[2] | 1 | /****************************************************************************
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| 2 | **
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[846] | 3 | ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
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[561] | 4 | ** All rights reserved.
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| 5 | ** Contact: Nokia Corporation (qt-info@nokia.com)
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[2] | 6 | **
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| 7 | ** This file is part of the QtGui module of the Qt Toolkit.
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| 8 | **
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| 9 | ** $QT_BEGIN_LICENSE:LGPL$
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| 10 | ** Commercial Usage
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| 11 | ** Licensees holding valid Qt Commercial licenses may use this file in
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| 12 | ** accordance with the Qt Commercial License Agreement provided with the
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| 13 | ** Software or, alternatively, in accordance with the terms contained in
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| 14 | ** a written agreement between you and Nokia.
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| 15 | **
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| 16 | ** GNU Lesser General Public License Usage
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| 17 | ** Alternatively, this file may be used under the terms of the GNU Lesser
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| 18 | ** General Public License version 2.1 as published by the Free Software
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| 19 | ** Foundation and appearing in the file LICENSE.LGPL included in the
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| 20 | ** packaging of this file. Please review the following information to
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| 21 | ** ensure the GNU Lesser General Public License version 2.1 requirements
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| 22 | ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
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| 23 | **
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[561] | 24 | ** In addition, as a special exception, Nokia gives you certain additional
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| 25 | ** rights. These rights are described in the Nokia Qt LGPL Exception
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| 26 | ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
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[2] | 27 | **
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| 28 | ** GNU General Public License Usage
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| 29 | ** Alternatively, this file may be used under the terms of the GNU
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| 30 | ** General Public License version 3.0 as published by the Free Software
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| 31 | ** Foundation and appearing in the file LICENSE.GPL included in the
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| 32 | ** packaging of this file. Please review the following information to
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| 33 | ** ensure the GNU General Public License version 3.0 requirements will be
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| 34 | ** met: http://www.gnu.org/copyleft/gpl.html.
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| 35 | **
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[561] | 36 | ** If you have questions regarding the use of this file, please contact
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| 37 | ** Nokia at qt-info@nokia.com.
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[2] | 38 | ** $QT_END_LICENSE$
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| 39 | **
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| 40 | ****************************************************************************/
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| 41 |
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| 42 | #include "qfont.h"
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| 43 | #include "qpaintdevice.h"
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| 44 | #include "qfontmetrics.h"
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| 45 |
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| 46 | #include "qfont_p.h"
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| 47 | #include "qfontengine_p.h"
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| 48 | #include <private/qunicodetables_p.h>
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| 49 |
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| 50 | #include <math.h>
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| 51 |
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| 52 | #ifdef Q_WS_X11
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| 53 | #include "qx11info_x11.h"
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| 54 | #endif
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| 55 |
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| 56 | QT_BEGIN_NAMESPACE
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| 57 |
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| 58 | #ifdef Q_WS_X11
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| 59 | extern const QX11Info *qt_x11Info(const QPaintDevice *pd);
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| 60 | #endif
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| 61 |
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| 62 | extern void qt_format_text(const QFont& font, const QRectF &_r,
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| 63 | int tf, const QString &text, QRectF *brect,
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| 64 | int tabStops, int *tabArray, int tabArrayLen,
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| 65 | QPainter *painter);
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[769] | 66 | Q_GUI_EXPORT extern int qt_defaultDpi();
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[2] | 67 |
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| 68 | /*****************************************************************************
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| 69 | QFontMetrics member functions
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| 70 | *****************************************************************************/
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| 71 |
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| 72 | /*!
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| 73 | \class QFontMetrics
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| 74 | \reentrant
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| 75 |
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| 76 | \brief The QFontMetrics class provides font metrics information.
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| 77 |
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[561] | 78 | \ingroup painting
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[2] | 79 | \ingroup shared
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| 80 |
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| 81 | QFontMetrics functions calculate the size of characters and
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| 82 | strings for a given font. There are three ways you can create a
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| 83 | QFontMetrics object:
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| 84 |
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| 85 | \list 1
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| 86 | \o Calling the QFontMetrics constructor with a QFont creates a
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| 87 | font metrics object for a screen-compatible font, i.e. the font
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| 88 | cannot be a printer font. If the font is changed
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| 89 | later, the font metrics object is \e not updated.
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| 90 |
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| 91 | (Note: If you use a printer font the values returned may be
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| 92 | inaccurate. Printer fonts are not always accessible so the nearest
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| 93 | screen font is used if a printer font is supplied.)
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| 94 |
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| 95 | \o QWidget::fontMetrics() returns the font metrics for a widget's
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| 96 | font. This is equivalent to QFontMetrics(widget->font()). If the
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| 97 | widget's font is changed later, the font metrics object is \e not
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| 98 | updated.
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| 99 |
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| 100 | \o QPainter::fontMetrics() returns the font metrics for a
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| 101 | painter's current font. If the painter's font is changed later, the
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| 102 | font metrics object is \e not updated.
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| 103 | \endlist
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| 104 |
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| 105 | Once created, the object provides functions to access the
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| 106 | individual metrics of the font, its characters, and for strings
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| 107 | rendered in the font.
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| 108 |
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| 109 | There are several functions that operate on the font: ascent(),
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| 110 | descent(), height(), leading() and lineSpacing() return the basic
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| 111 | size properties of the font. The underlinePos(), overlinePos(),
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| 112 | strikeOutPos() and lineWidth() functions, return the properties of
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| 113 | the line that underlines, overlines or strikes out the
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| 114 | characters. These functions are all fast.
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| 115 |
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| 116 | There are also some functions that operate on the set of glyphs in
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| 117 | the font: minLeftBearing(), minRightBearing() and maxWidth().
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| 118 | These are by necessity slow, and we recommend avoiding them if
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| 119 | possible.
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| 120 |
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| 121 | For each character, you can get its width(), leftBearing() and
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| 122 | rightBearing() and find out whether it is in the font using
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| 123 | inFont(). You can also treat the character as a string, and use
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| 124 | the string functions on it.
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| 125 |
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| 126 | The string functions include width(), to return the width of a
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| 127 | string in pixels (or points, for a printer), boundingRect(), to
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| 128 | return a rectangle large enough to contain the rendered string,
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| 129 | and size(), to return the size of that rectangle.
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| 130 |
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| 131 | Example:
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| 132 | \snippet doc/src/snippets/code/src_gui_text_qfontmetrics.cpp 0
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| 133 |
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| 134 | \sa QFont, QFontInfo, QFontDatabase, QFontComboBox, {Character Map Example}
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| 135 | */
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| 136 |
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| 137 | /*!
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| 138 | \fn QRect QFontMetrics::boundingRect(int x, int y, int width, int height,
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| 139 | int flags, const QString &text, int tabStops, int *tabArray) const
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| 140 | \overload
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| 141 |
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| 142 | Returns the bounding rectangle for the given \a text within the
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| 143 | rectangle specified by the \a x and \a y coordinates, \a width, and
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| 144 | \a height.
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| 145 |
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| 146 | If Qt::TextExpandTabs is set in \a flags and \a tabArray is
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| 147 | non-null, it specifies a 0-terminated sequence of pixel-positions
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| 148 | for tabs; otherwise, if \a tabStops is non-zero, it is used as the
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| 149 | tab spacing (in pixels).
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| 150 | */
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| 151 |
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| 152 | /*!
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| 153 | Constructs a font metrics object for \a font.
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| 154 |
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| 155 | The font metrics will be compatible with the paintdevice used to
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| 156 | create \a font.
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| 157 |
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| 158 | The font metrics object holds the information for the font that is
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| 159 | passed in the constructor at the time it is created, and is not
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| 160 | updated if the font's attributes are changed later.
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| 161 |
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| 162 | Use QFontMetrics(const QFont &, QPaintDevice *) to get the font
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| 163 | metrics that are compatible with a certain paint device.
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| 164 | */
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| 165 | QFontMetrics::QFontMetrics(const QFont &font)
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[561] | 166 | : d(font.d.data())
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[2] | 167 | {
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| 168 | }
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| 169 |
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| 170 | /*!
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| 171 | Constructs a font metrics object for \a font and \a paintdevice.
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| 172 |
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| 173 | The font metrics will be compatible with the paintdevice passed.
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| 174 | If the \a paintdevice is 0, the metrics will be screen-compatible,
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| 175 | ie. the metrics you get if you use the font for drawing text on a
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| 176 | \link QWidget widgets\endlink or \link QPixmap pixmaps\endlink,
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| 177 | not on a QPicture or QPrinter.
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| 178 |
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| 179 | The font metrics object holds the information for the font that is
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| 180 | passed in the constructor at the time it is created, and is not
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| 181 | updated if the font's attributes are changed later.
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| 182 | */
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| 183 | QFontMetrics::QFontMetrics(const QFont &font, QPaintDevice *paintdevice)
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| 184 | {
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| 185 | int dpi = paintdevice ? paintdevice->logicalDpiY() : qt_defaultDpi();
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| 186 | #ifdef Q_WS_X11
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| 187 | const QX11Info *info = qt_x11Info(paintdevice);
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| 188 | int screen = info ? info->screen() : 0;
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| 189 | #else
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| 190 | const int screen = 0;
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| 191 | #endif
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| 192 | if (font.d->dpi != dpi || font.d->screen != screen ) {
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| 193 | d = new QFontPrivate(*font.d);
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| 194 | d->dpi = dpi;
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| 195 | d->screen = screen;
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| 196 | } else {
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[561] | 197 | d = font.d.data();
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[2] | 198 | }
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| 199 |
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| 200 | }
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| 201 |
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| 202 | /*!
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| 203 | Constructs a copy of \a fm.
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| 204 | */
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| 205 | QFontMetrics::QFontMetrics(const QFontMetrics &fm)
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[561] | 206 | : d(fm.d.data())
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| 207 | {
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| 208 | }
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[2] | 209 |
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| 210 | /*!
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| 211 | Destroys the font metrics object and frees all allocated
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| 212 | resources.
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| 213 | */
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| 214 | QFontMetrics::~QFontMetrics()
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| 215 | {
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| 216 | }
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| 217 |
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| 218 | /*!
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| 219 | Assigns the font metrics \a fm.
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| 220 | */
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| 221 | QFontMetrics &QFontMetrics::operator=(const QFontMetrics &fm)
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| 222 | {
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[561] | 223 | d = fm.d.data();
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[2] | 224 | return *this;
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| 225 | }
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| 226 |
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| 227 | /*!
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| 228 | \overload
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| 229 | Returns true if \a other is equal to this object; otherwise
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| 230 | returns false.
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| 231 |
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| 232 | Two font metrics are considered equal if they were constructed
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| 233 | from the same QFont and the paint devices they were constructed
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| 234 | for are considered compatible.
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| 235 |
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| 236 | \sa operator!=()
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| 237 | */
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| 238 | bool QFontMetrics::operator ==(const QFontMetrics &other) const
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| 239 | {
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| 240 | return d == other.d;
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| 241 | }
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| 242 |
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| 243 | /*!
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| 244 | Returns true if \a other is equal to this object; otherwise
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| 245 | returns false.
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| 246 |
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| 247 | Two font metrics are considered equal if they were constructed
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| 248 | from the same QFont and the paint devices they were constructed
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| 249 | for are considered compatible.
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| 250 |
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| 251 | \sa operator!=()
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| 252 | */
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| 253 | bool QFontMetrics::operator ==(const QFontMetrics &other)
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| 254 | {
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| 255 | return d == other.d;
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| 256 | }
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| 257 |
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| 258 | /*!
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| 259 | \fn bool QFontMetrics::operator!=(const QFontMetrics &other)
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| 260 |
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| 261 | Returns true if \a other is not equal to this object; otherwise returns false.
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| 262 |
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| 263 | Two font metrics are considered equal if they were constructed
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| 264 | from the same QFont and the paint devices they were constructed
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| 265 | for are considered compatible.
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| 266 |
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| 267 | \sa operator==()
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| 268 | */
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| 269 |
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| 270 | /*!
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| 271 | \fn bool QFontMetrics::operator !=(const QFontMetrics &other) const
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| 272 |
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| 273 | Returns true if \a other is not equal to this object; otherwise returns false.
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| 274 |
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| 275 | Two font metrics are considered equal if they were constructed
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| 276 | from the same QFont and the paint devices they were constructed
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| 277 | for are considered compatible.
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| 278 |
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| 279 | \sa operator==()
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| 280 | */
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| 281 |
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| 282 | /*!
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| 283 | Returns the ascent of the font.
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| 284 |
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| 285 | The ascent of a font is the distance from the baseline to the
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| 286 | highest position characters extend to. In practice, some font
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| 287 | designers break this rule, e.g. when they put more than one accent
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| 288 | on top of a character, or to accommodate an unusual character in
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| 289 | an exotic language, so it is possible (though rare) that this
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| 290 | value will be too small.
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| 291 |
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| 292 | \sa descent()
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| 293 | */
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| 294 | int QFontMetrics::ascent() const
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| 295 | {
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| 296 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
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| 297 | Q_ASSERT(engine != 0);
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| 298 | return qRound(engine->ascent());
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| 299 | }
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| 300 |
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| 301 |
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| 302 | /*!
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| 303 | Returns the descent of the font.
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| 304 |
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| 305 | The descent is the distance from the base line to the lowest point
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| 306 | characters extend to. In practice, some font designers break this rule,
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| 307 | e.g. to accommodate an unusual character in an exotic language, so
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| 308 | it is possible (though rare) that this value will be too small.
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| 309 |
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| 310 | \sa ascent()
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| 311 | */
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| 312 | int QFontMetrics::descent() const
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| 313 | {
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| 314 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
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| 315 | Q_ASSERT(engine != 0);
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| 316 | return qRound(engine->descent());
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| 317 | }
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| 318 |
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| 319 | /*!
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| 320 | Returns the height of the font.
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| 321 |
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| 322 | This is always equal to ascent()+descent()+1 (the 1 is for the
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| 323 | base line).
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| 324 |
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| 325 | \sa leading(), lineSpacing()
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| 326 | */
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| 327 | int QFontMetrics::height() const
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| 328 | {
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| 329 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
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| 330 | Q_ASSERT(engine != 0);
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[846] | 331 | return qRound(engine->ascent()) + qRound(engine->descent()) + 1;
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[2] | 332 | }
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| 333 |
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| 334 | /*!
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| 335 | Returns the leading of the font.
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| 336 |
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| 337 | This is the natural inter-line spacing.
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| 338 |
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| 339 | \sa height(), lineSpacing()
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| 340 | */
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| 341 | int QFontMetrics::leading() const
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| 342 | {
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| 343 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
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| 344 | Q_ASSERT(engine != 0);
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| 345 | return qRound(engine->leading());
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| 346 | }
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| 347 |
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| 348 | /*!
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| 349 | Returns the distance from one base line to the next.
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| 350 |
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| 351 | This value is always equal to leading()+height().
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| 352 |
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| 353 | \sa height(), leading()
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| 354 | */
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| 355 | int QFontMetrics::lineSpacing() const
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| 356 | {
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| 357 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
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| 358 | Q_ASSERT(engine != 0);
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[846] | 359 | return qRound(engine->leading()) + qRound(engine->ascent()) + qRound(engine->descent()) + 1;
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[2] | 360 | }
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| 361 |
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| 362 | /*!
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| 363 | Returns the minimum left bearing of the font.
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| 364 |
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| 365 | This is the smallest leftBearing(char) of all characters in the
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| 366 | font.
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| 367 |
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| 368 | Note that this function can be very slow if the font is large.
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| 369 |
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| 370 | \sa minRightBearing(), leftBearing()
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| 371 | */
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| 372 | int QFontMetrics::minLeftBearing() const
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| 373 | {
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| 374 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
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| 375 | Q_ASSERT(engine != 0);
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| 376 | return qRound(engine->minLeftBearing());
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| 377 | }
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| 378 |
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| 379 | /*!
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| 380 | Returns the minimum right bearing of the font.
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| 381 |
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| 382 | This is the smallest rightBearing(char) of all characters in the
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| 383 | font.
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| 384 |
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| 385 | Note that this function can be very slow if the font is large.
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| 386 |
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| 387 | \sa minLeftBearing(), rightBearing()
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| 388 | */
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| 389 | int QFontMetrics::minRightBearing() const
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| 390 | {
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| 391 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
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| 392 | Q_ASSERT(engine != 0);
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| 393 | return qRound(engine->minRightBearing());
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| 394 | }
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| 395 |
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| 396 | /*!
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| 397 | Returns the width of the widest character in the font.
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| 398 | */
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| 399 | int QFontMetrics::maxWidth() const
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| 400 | {
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| 401 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
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| 402 | Q_ASSERT(engine != 0);
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| 403 | return qRound(engine->maxCharWidth());
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| 404 | }
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| 405 |
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| 406 | /*!
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| 407 | Returns the 'x' height of the font. This is often but not always
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| 408 | the same as the height of the character 'x'.
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| 409 | */
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| 410 | int QFontMetrics::xHeight() const
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| 411 | {
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| 412 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
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| 413 | Q_ASSERT(engine != 0);
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| 414 | if (d->capital == QFont::SmallCaps)
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| 415 | return qRound(d->smallCapsFontPrivate()->engineForScript(QUnicodeTables::Common)->ascent());
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| 416 | return qRound(engine->xHeight());
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| 417 | }
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| 418 |
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| 419 | /*!
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| 420 | \since 4.2
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| 421 |
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| 422 | Returns the average width of glyphs in the font.
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| 423 | */
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| 424 | int QFontMetrics::averageCharWidth() const
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| 425 | {
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| 426 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
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| 427 | Q_ASSERT(engine != 0);
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| 428 | return qRound(engine->averageCharWidth());
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| 429 | }
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| 430 |
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| 431 | /*!
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| 432 | Returns true if character \a ch is a valid character in the font;
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| 433 | otherwise returns false.
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| 434 | */
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| 435 | bool QFontMetrics::inFont(QChar ch) const
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| 436 | {
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| 437 | const int script = QUnicodeTables::script(ch);
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| 438 | QFontEngine *engine = d->engineForScript(script);
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| 439 | Q_ASSERT(engine != 0);
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| 440 | if (engine->type() == QFontEngine::Box)
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| 441 | return false;
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| 442 | return engine->canRender(&ch, 1);
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| 443 | }
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| 444 |
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| 445 | /*!
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| 446 | Returns the left bearing of character \a ch in the font.
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| 447 |
|
---|
| 448 | The left bearing is the right-ward distance of the left-most pixel
|
---|
| 449 | of the character from the logical origin of the character. This
|
---|
| 450 | value is negative if the pixels of the character extend to the
|
---|
| 451 | left of the logical origin.
|
---|
| 452 |
|
---|
| 453 | See width(QChar) for a graphical description of this metric.
|
---|
| 454 |
|
---|
| 455 | \sa rightBearing(), minLeftBearing(), width()
|
---|
| 456 | */
|
---|
| 457 | int QFontMetrics::leftBearing(QChar ch) const
|
---|
| 458 | {
|
---|
| 459 | const int script = QUnicodeTables::script(ch);
|
---|
| 460 | QFontEngine *engine;
|
---|
| 461 | if (d->capital == QFont::SmallCaps && ch.isLower())
|
---|
| 462 | engine = d->smallCapsFontPrivate()->engineForScript(script);
|
---|
| 463 | else
|
---|
| 464 | engine = d->engineForScript(script);
|
---|
| 465 | Q_ASSERT(engine != 0);
|
---|
| 466 | if (engine->type() == QFontEngine::Box)
|
---|
| 467 | return 0;
|
---|
| 468 |
|
---|
| 469 | d->alterCharForCapitalization(ch);
|
---|
| 470 |
|
---|
| 471 | QGlyphLayoutArray<10> glyphs;
|
---|
| 472 | int nglyphs = 9;
|
---|
| 473 | engine->stringToCMap(&ch, 1, &glyphs, &nglyphs, 0);
|
---|
| 474 | // ### can nglyphs != 1 happen at all? Not currently I think
|
---|
[769] | 475 | qreal lb;
|
---|
| 476 | engine->getGlyphBearings(glyphs.glyphs[0], &lb);
|
---|
| 477 | return qRound(lb);
|
---|
[2] | 478 | }
|
---|
| 479 |
|
---|
| 480 | /*!
|
---|
| 481 | Returns the right bearing of character \a ch in the font.
|
---|
| 482 |
|
---|
| 483 | The right bearing is the left-ward distance of the right-most
|
---|
| 484 | pixel of the character from the logical origin of a subsequent
|
---|
| 485 | character. This value is negative if the pixels of the character
|
---|
| 486 | extend to the right of the width() of the character.
|
---|
| 487 |
|
---|
| 488 | See width() for a graphical description of this metric.
|
---|
| 489 |
|
---|
| 490 | \sa leftBearing(), minRightBearing(), width()
|
---|
| 491 | */
|
---|
| 492 | int QFontMetrics::rightBearing(QChar ch) const
|
---|
| 493 | {
|
---|
| 494 | const int script = QUnicodeTables::script(ch);
|
---|
| 495 | QFontEngine *engine;
|
---|
| 496 | if (d->capital == QFont::SmallCaps && ch.isLower())
|
---|
| 497 | engine = d->smallCapsFontPrivate()->engineForScript(script);
|
---|
| 498 | else
|
---|
| 499 | engine = d->engineForScript(script);
|
---|
| 500 | Q_ASSERT(engine != 0);
|
---|
| 501 | if (engine->type() == QFontEngine::Box)
|
---|
| 502 | return 0;
|
---|
| 503 |
|
---|
| 504 | d->alterCharForCapitalization(ch);
|
---|
| 505 |
|
---|
| 506 | QGlyphLayoutArray<10> glyphs;
|
---|
| 507 | int nglyphs = 9;
|
---|
| 508 | engine->stringToCMap(&ch, 1, &glyphs, &nglyphs, 0);
|
---|
| 509 | // ### can nglyphs != 1 happen at all? Not currently I think
|
---|
[769] | 510 | qreal rb;
|
---|
| 511 | engine->getGlyphBearings(glyphs.glyphs[0], 0, &rb);
|
---|
| 512 | return qRound(rb);
|
---|
[2] | 513 | }
|
---|
| 514 |
|
---|
| 515 | /*!
|
---|
| 516 | Returns the width in pixels of the first \a len characters of \a
|
---|
| 517 | text. If \a len is negative (the default), the entire string is
|
---|
| 518 | used.
|
---|
| 519 |
|
---|
| 520 | Note that this value is \e not equal to boundingRect().width();
|
---|
| 521 | boundingRect() returns a rectangle describing the pixels this
|
---|
| 522 | string will cover whereas width() returns the distance to where
|
---|
| 523 | the next string should be drawn.
|
---|
| 524 |
|
---|
| 525 | \sa boundingRect()
|
---|
| 526 | */
|
---|
| 527 | int QFontMetrics::width(const QString &text, int len) const
|
---|
| 528 | {
|
---|
[846] | 529 | return width(text, len, 0);
|
---|
| 530 | }
|
---|
| 531 |
|
---|
| 532 | /*!
|
---|
| 533 | \internal
|
---|
| 534 | */
|
---|
| 535 | int QFontMetrics::width(const QString &text, int len, int flags) const
|
---|
| 536 | {
|
---|
[561] | 537 | int pos = text.indexOf(QLatin1Char('\x9c'));
|
---|
| 538 | if (pos != -1) {
|
---|
| 539 | len = (len < 0) ? pos : qMin(pos, len);
|
---|
| 540 | } else if (len < 0) {
|
---|
[2] | 541 | len = text.length();
|
---|
[561] | 542 | }
|
---|
[2] | 543 | if (len == 0)
|
---|
| 544 | return 0;
|
---|
| 545 |
|
---|
[846] | 546 | if (flags & Qt::TextBypassShaping) {
|
---|
| 547 | // Skip harfbuzz complex shaping, only use advances
|
---|
| 548 | int numGlyphs = len;
|
---|
| 549 | QVarLengthGlyphLayoutArray glyphs(numGlyphs);
|
---|
| 550 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
|
---|
| 551 | if (!engine->stringToCMap(text.data(), len, &glyphs, &numGlyphs, 0)) {
|
---|
| 552 | glyphs.resize(numGlyphs);
|
---|
| 553 | if (!engine->stringToCMap(text.data(), len, &glyphs, &numGlyphs, 0))
|
---|
| 554 | Q_ASSERT_X(false, Q_FUNC_INFO, "stringToCMap shouldn't fail twice");
|
---|
| 555 | }
|
---|
| 556 |
|
---|
| 557 | QFixed width;
|
---|
| 558 | for (int i = 0; i < numGlyphs; ++i)
|
---|
| 559 | width += glyphs.advances_x[i];
|
---|
| 560 | return qRound(width);
|
---|
| 561 | }
|
---|
| 562 |
|
---|
| 563 | QStackTextEngine layout(text, d.data());
|
---|
[2] | 564 | layout.ignoreBidi = true;
|
---|
| 565 | return qRound(layout.width(0, len));
|
---|
| 566 | }
|
---|
| 567 |
|
---|
| 568 | /*!
|
---|
| 569 | \overload
|
---|
| 570 |
|
---|
| 571 | \img bearings.png Bearings
|
---|
| 572 |
|
---|
| 573 | Returns the logical width of character \a ch in pixels. This is a
|
---|
| 574 | distance appropriate for drawing a subsequent character after \a
|
---|
| 575 | ch.
|
---|
| 576 |
|
---|
| 577 | Some of the metrics are described in the image to the right. The
|
---|
| 578 | central dark rectangles cover the logical width() of each
|
---|
| 579 | character. The outer pale rectangles cover the leftBearing() and
|
---|
| 580 | rightBearing() of each character. Notice that the bearings of "f"
|
---|
| 581 | in this particular font are both negative, while the bearings of
|
---|
| 582 | "o" are both positive.
|
---|
| 583 |
|
---|
| 584 | \warning This function will produce incorrect results for Arabic
|
---|
| 585 | characters or non-spacing marks in the middle of a string, as the
|
---|
| 586 | glyph shaping and positioning of marks that happens when
|
---|
[561] | 587 | processing strings cannot be taken into account. When implementing
|
---|
| 588 | an interactive text control, use QTextLayout instead.
|
---|
[2] | 589 |
|
---|
[561] | 590 | \sa boundingRect()
|
---|
[2] | 591 | */
|
---|
| 592 | int QFontMetrics::width(QChar ch) const
|
---|
| 593 | {
|
---|
| 594 | if (QChar::category(ch.unicode()) == QChar::Mark_NonSpacing)
|
---|
| 595 | return 0;
|
---|
| 596 |
|
---|
| 597 | const int script = QUnicodeTables::script(ch);
|
---|
| 598 | QFontEngine *engine;
|
---|
| 599 | if (d->capital == QFont::SmallCaps && ch.isLower())
|
---|
| 600 | engine = d->smallCapsFontPrivate()->engineForScript(script);
|
---|
| 601 | else
|
---|
| 602 | engine = d->engineForScript(script);
|
---|
| 603 | Q_ASSERT(engine != 0);
|
---|
| 604 |
|
---|
| 605 | d->alterCharForCapitalization(ch);
|
---|
| 606 |
|
---|
| 607 | QGlyphLayoutArray<8> glyphs;
|
---|
| 608 | int nglyphs = 7;
|
---|
| 609 | engine->stringToCMap(&ch, 1, &glyphs, &nglyphs, 0);
|
---|
| 610 | return qRound(glyphs.advances_x[0]);
|
---|
| 611 | }
|
---|
| 612 |
|
---|
| 613 | /*! \obsolete
|
---|
| 614 |
|
---|
| 615 | Returns the width of the character at position \a pos in the
|
---|
| 616 | string \a text.
|
---|
| 617 |
|
---|
| 618 | The whole string is needed, as the glyph drawn may change
|
---|
| 619 | depending on the context (the letter before and after the current
|
---|
| 620 | one) for some languages (e.g. Arabic).
|
---|
| 621 |
|
---|
| 622 | This function also takes non spacing marks and ligatures into
|
---|
| 623 | account.
|
---|
| 624 | */
|
---|
| 625 | int QFontMetrics::charWidth(const QString &text, int pos) const
|
---|
| 626 | {
|
---|
| 627 | if (pos < 0 || pos > (int)text.length())
|
---|
| 628 | return 0;
|
---|
| 629 |
|
---|
| 630 | QChar ch = text.unicode()[pos];
|
---|
| 631 | const int script = QUnicodeTables::script(ch);
|
---|
| 632 | int width;
|
---|
| 633 |
|
---|
| 634 | if (script != QUnicodeTables::Common) {
|
---|
| 635 | // complex script shaping. Have to do some hard work
|
---|
| 636 | int from = qMax(0, pos - 8);
|
---|
| 637 | int to = qMin(text.length(), pos + 8);
|
---|
| 638 | QString cstr = QString::fromRawData(text.unicode() + from, to - from);
|
---|
[846] | 639 | QStackTextEngine layout(cstr, d.data());
|
---|
[2] | 640 | layout.ignoreBidi = true;
|
---|
| 641 | layout.itemize();
|
---|
| 642 | width = qRound(layout.width(pos-from, 1));
|
---|
| 643 | } else if (QChar::category(ch.unicode()) == QChar::Mark_NonSpacing) {
|
---|
| 644 | width = 0;
|
---|
| 645 | } else {
|
---|
| 646 | QFontEngine *engine;
|
---|
| 647 | if (d->capital == QFont::SmallCaps && ch.isLower())
|
---|
| 648 | engine = d->smallCapsFontPrivate()->engineForScript(script);
|
---|
| 649 | else
|
---|
| 650 | engine = d->engineForScript(script);
|
---|
| 651 | Q_ASSERT(engine != 0);
|
---|
| 652 |
|
---|
| 653 | d->alterCharForCapitalization(ch);
|
---|
| 654 |
|
---|
| 655 | QGlyphLayoutArray<8> glyphs;
|
---|
| 656 | int nglyphs = 7;
|
---|
| 657 | engine->stringToCMap(&ch, 1, &glyphs, &nglyphs, 0);
|
---|
| 658 | width = qRound(glyphs.advances_x[0]);
|
---|
| 659 | }
|
---|
| 660 | return width;
|
---|
| 661 | }
|
---|
| 662 |
|
---|
| 663 | /*!
|
---|
| 664 | Returns the bounding rectangle of the characters in the string
|
---|
| 665 | specified by \a text. The bounding rectangle always covers at least
|
---|
| 666 | the set of pixels the text would cover if drawn at (0, 0).
|
---|
| 667 |
|
---|
| 668 | Note that the bounding rectangle may extend to the left of (0, 0),
|
---|
| 669 | e.g. for italicized fonts, and that the width of the returned
|
---|
| 670 | rectangle might be different than what the width() method returns.
|
---|
| 671 |
|
---|
| 672 | If you want to know the advance width of the string (to layout
|
---|
| 673 | a set of strings next to each other), use width() instead.
|
---|
| 674 |
|
---|
| 675 | Newline characters are processed as normal characters, \e not as
|
---|
| 676 | linebreaks.
|
---|
| 677 |
|
---|
| 678 | The height of the bounding rectangle is at least as large as the
|
---|
| 679 | value returned by height().
|
---|
| 680 |
|
---|
| 681 | \sa width(), height(), QPainter::boundingRect(), tightBoundingRect()
|
---|
| 682 | */
|
---|
| 683 | QRect QFontMetrics::boundingRect(const QString &text) const
|
---|
| 684 | {
|
---|
| 685 | if (text.length() == 0)
|
---|
| 686 | return QRect();
|
---|
| 687 |
|
---|
[846] | 688 | QStackTextEngine layout(text, d.data());
|
---|
[2] | 689 | layout.ignoreBidi = true;
|
---|
| 690 | layout.itemize();
|
---|
| 691 | glyph_metrics_t gm = layout.boundingBox(0, text.length());
|
---|
| 692 | return QRect(qRound(gm.x), qRound(gm.y), qRound(gm.width), qRound(gm.height));
|
---|
| 693 | }
|
---|
| 694 |
|
---|
| 695 | /*!
|
---|
| 696 | Returns the rectangle that is covered by ink if character \a ch
|
---|
| 697 | were to be drawn at the origin of the coordinate system.
|
---|
| 698 |
|
---|
[561] | 699 | Note that the bounding rectangle may extend to the left of (0, 0)
|
---|
| 700 | (e.g., for italicized fonts), and that the text output may cover \e
|
---|
[2] | 701 | all pixels in the bounding rectangle. For a space character the rectangle
|
---|
| 702 | will usually be empty.
|
---|
| 703 |
|
---|
| 704 | Note that the rectangle usually extends both above and below the
|
---|
| 705 | base line.
|
---|
| 706 |
|
---|
| 707 | \warning The width of the returned rectangle is not the advance width
|
---|
| 708 | of the character. Use boundingRect(const QString &) or width() instead.
|
---|
| 709 |
|
---|
| 710 | \sa width()
|
---|
| 711 | */
|
---|
| 712 | QRect QFontMetrics::boundingRect(QChar ch) const
|
---|
| 713 | {
|
---|
| 714 | const int script = QUnicodeTables::script(ch);
|
---|
| 715 | QFontEngine *engine;
|
---|
| 716 | if (d->capital == QFont::SmallCaps && ch.isLower())
|
---|
| 717 | engine = d->smallCapsFontPrivate()->engineForScript(script);
|
---|
| 718 | else
|
---|
| 719 | engine = d->engineForScript(script);
|
---|
| 720 | Q_ASSERT(engine != 0);
|
---|
| 721 |
|
---|
| 722 | d->alterCharForCapitalization(ch);
|
---|
| 723 |
|
---|
| 724 | QGlyphLayoutArray<10> glyphs;
|
---|
| 725 | int nglyphs = 9;
|
---|
| 726 | engine->stringToCMap(&ch, 1, &glyphs, &nglyphs, 0);
|
---|
| 727 | glyph_metrics_t gm = engine->boundingBox(glyphs.glyphs[0]);
|
---|
| 728 | return QRect(qRound(gm.x), qRound(gm.y), qRound(gm.width), qRound(gm.height));
|
---|
| 729 | }
|
---|
| 730 |
|
---|
| 731 | /*!
|
---|
| 732 | \overload
|
---|
| 733 |
|
---|
| 734 | Returns the bounding rectangle of the characters in the string
|
---|
| 735 | specified by \a text, which is the set of pixels the text would
|
---|
| 736 | cover if drawn at (0, 0). The drawing, and hence the bounding
|
---|
| 737 | rectangle, is constrained to the rectangle \a rect.
|
---|
| 738 |
|
---|
| 739 | The \a flags argument is the bitwise OR of the following flags:
|
---|
| 740 | \list
|
---|
| 741 | \o Qt::AlignLeft aligns to the left border, except for
|
---|
| 742 | Arabic and Hebrew where it aligns to the right.
|
---|
| 743 | \o Qt::AlignRight aligns to the right border, except for
|
---|
| 744 | Arabic and Hebrew where it aligns to the left.
|
---|
| 745 | \o Qt::AlignJustify produces justified text.
|
---|
| 746 | \o Qt::AlignHCenter aligns horizontally centered.
|
---|
| 747 | \o Qt::AlignTop aligns to the top border.
|
---|
| 748 | \o Qt::AlignBottom aligns to the bottom border.
|
---|
| 749 | \o Qt::AlignVCenter aligns vertically centered
|
---|
| 750 | \o Qt::AlignCenter (== \c{Qt::AlignHCenter | Qt::AlignVCenter})
|
---|
| 751 | \o Qt::TextSingleLine ignores newline characters in the text.
|
---|
| 752 | \o Qt::TextExpandTabs expands tabs (see below)
|
---|
[561] | 753 | \o Qt::TextShowMnemonic interprets "&x" as \underline{x}; i.e., underlined.
|
---|
[2] | 754 | \o Qt::TextWordWrap breaks the text to fit the rectangle.
|
---|
| 755 | \endlist
|
---|
| 756 |
|
---|
| 757 | Qt::Horizontal alignment defaults to Qt::AlignLeft and vertical
|
---|
| 758 | alignment defaults to Qt::AlignTop.
|
---|
| 759 |
|
---|
| 760 | If several of the horizontal or several of the vertical alignment
|
---|
| 761 | flags are set, the resulting alignment is undefined.
|
---|
| 762 |
|
---|
| 763 | If Qt::TextExpandTabs is set in \a flags, then: if \a tabArray is
|
---|
| 764 | non-null, it specifies a 0-terminated sequence of pixel-positions
|
---|
| 765 | for tabs; otherwise if \a tabStops is non-zero, it is used as the
|
---|
| 766 | tab spacing (in pixels).
|
---|
| 767 |
|
---|
| 768 | Note that the bounding rectangle may extend to the left of (0, 0),
|
---|
| 769 | e.g. for italicized fonts, and that the text output may cover \e
|
---|
| 770 | all pixels in the bounding rectangle.
|
---|
| 771 |
|
---|
| 772 | Newline characters are processed as linebreaks.
|
---|
| 773 |
|
---|
| 774 | Despite the different actual character heights, the heights of the
|
---|
| 775 | bounding rectangles of "Yes" and "yes" are the same.
|
---|
| 776 |
|
---|
| 777 | The bounding rectangle returned by this function is somewhat larger
|
---|
| 778 | than that calculated by the simpler boundingRect() function. This
|
---|
| 779 | function uses the \link minLeftBearing() maximum left \endlink and
|
---|
| 780 | \link minRightBearing() right \endlink font bearings as is
|
---|
| 781 | necessary for multi-line text to align correctly. Also,
|
---|
| 782 | fontHeight() and lineSpacing() are used to calculate the height,
|
---|
| 783 | rather than individual character heights.
|
---|
| 784 |
|
---|
| 785 | \sa width(), QPainter::boundingRect(), Qt::Alignment
|
---|
| 786 | */
|
---|
| 787 | QRect QFontMetrics::boundingRect(const QRect &rect, int flags, const QString &text, int tabStops,
|
---|
| 788 | int *tabArray) const
|
---|
| 789 | {
|
---|
| 790 | int tabArrayLen = 0;
|
---|
| 791 | if (tabArray)
|
---|
| 792 | while (tabArray[tabArrayLen])
|
---|
| 793 | tabArrayLen++;
|
---|
| 794 |
|
---|
| 795 | QRectF rb;
|
---|
| 796 | QRectF rr(rect);
|
---|
[561] | 797 | qt_format_text(QFont(d.data()), rr, flags | Qt::TextDontPrint, text, &rb, tabStops, tabArray,
|
---|
[2] | 798 | tabArrayLen, 0);
|
---|
| 799 |
|
---|
| 800 | return rb.toAlignedRect();
|
---|
| 801 | }
|
---|
| 802 |
|
---|
| 803 | /*!
|
---|
| 804 | Returns the size in pixels of \a text.
|
---|
| 805 |
|
---|
| 806 | The \a flags argument is the bitwise OR of the following flags:
|
---|
| 807 | \list
|
---|
| 808 | \o Qt::TextSingleLine ignores newline characters.
|
---|
| 809 | \o Qt::TextExpandTabs expands tabs (see below)
|
---|
[561] | 810 | \o Qt::TextShowMnemonic interprets "&x" as \underline{x}; i.e., underlined.
|
---|
[2] | 811 | \o Qt::TextWordBreak breaks the text to fit the rectangle.
|
---|
| 812 | \endlist
|
---|
| 813 |
|
---|
| 814 | If Qt::TextExpandTabs is set in \a flags, then: if \a tabArray is
|
---|
| 815 | non-null, it specifies a 0-terminated sequence of pixel-positions
|
---|
| 816 | for tabs; otherwise if \a tabStops is non-zero, it is used as the
|
---|
| 817 | tab spacing (in pixels).
|
---|
| 818 |
|
---|
| 819 | Newline characters are processed as linebreaks.
|
---|
| 820 |
|
---|
| 821 | Despite the different actual character heights, the heights of the
|
---|
| 822 | bounding rectangles of "Yes" and "yes" are the same.
|
---|
| 823 |
|
---|
| 824 | \sa boundingRect()
|
---|
| 825 | */
|
---|
| 826 | QSize QFontMetrics::size(int flags, const QString &text, int tabStops, int *tabArray) const
|
---|
| 827 | {
|
---|
[561] | 828 | return boundingRect(QRect(0,0,0,0), flags | Qt::TextLongestVariant, text, tabStops, tabArray).size();
|
---|
[2] | 829 | }
|
---|
| 830 |
|
---|
| 831 | /*!
|
---|
| 832 | \since 4.3
|
---|
| 833 |
|
---|
| 834 | Returns a tight bounding rectangle around the characters in the
|
---|
| 835 | string specified by \a text. The bounding rectangle always covers
|
---|
| 836 | at least the set of pixels the text would cover if drawn at (0,
|
---|
| 837 | 0).
|
---|
| 838 |
|
---|
| 839 | Note that the bounding rectangle may extend to the left of (0, 0),
|
---|
| 840 | e.g. for italicized fonts, and that the width of the returned
|
---|
| 841 | rectangle might be different than what the width() method returns.
|
---|
| 842 |
|
---|
| 843 | If you want to know the advance width of the string (to layout
|
---|
| 844 | a set of strings next to each other), use width() instead.
|
---|
| 845 |
|
---|
| 846 | Newline characters are processed as normal characters, \e not as
|
---|
| 847 | linebreaks.
|
---|
| 848 |
|
---|
| 849 | \warning Calling this method is very slow on Windows.
|
---|
| 850 |
|
---|
| 851 | \sa width(), height(), boundingRect()
|
---|
| 852 | */
|
---|
| 853 | QRect QFontMetrics::tightBoundingRect(const QString &text) const
|
---|
| 854 | {
|
---|
| 855 | if (text.length() == 0)
|
---|
| 856 | return QRect();
|
---|
| 857 |
|
---|
[846] | 858 | QStackTextEngine layout(text, d.data());
|
---|
[2] | 859 | layout.ignoreBidi = true;
|
---|
| 860 | layout.itemize();
|
---|
| 861 | glyph_metrics_t gm = layout.tightBoundingBox(0, text.length());
|
---|
| 862 | return QRect(qRound(gm.x), qRound(gm.y), qRound(gm.width), qRound(gm.height));
|
---|
| 863 | }
|
---|
| 864 |
|
---|
| 865 |
|
---|
| 866 | /*!
|
---|
| 867 | \since 4.2
|
---|
| 868 |
|
---|
| 869 | If the string \a text is wider than \a width, returns an elided
|
---|
| 870 | version of the string (i.e., a string with "..." in it).
|
---|
| 871 | Otherwise, returns the original string.
|
---|
| 872 |
|
---|
| 873 | The \a mode parameter specifies whether the text is elided on the
|
---|
| 874 | left (e.g., "...tech"), in the middle (e.g., "Tr...ch"), or on
|
---|
| 875 | the right (e.g., "Trol...").
|
---|
| 876 |
|
---|
| 877 | The \a width is specified in pixels, not characters.
|
---|
| 878 |
|
---|
| 879 | The \a flags argument is optional and currently only supports
|
---|
| 880 | Qt::TextShowMnemonic as value.
|
---|
| 881 |
|
---|
| 882 | The elide mark will follow the \l{Qt::LayoutDirection}{layout
|
---|
| 883 | direction}; it will be on the right side of the text for
|
---|
| 884 | right-to-left layouts, and on the left side for right-to-left
|
---|
| 885 | layouts. Note that this behavior is independent of the text
|
---|
| 886 | language.
|
---|
| 887 | */
|
---|
| 888 | QString QFontMetrics::elidedText(const QString &text, Qt::TextElideMode mode, int width, int flags) const
|
---|
| 889 | {
|
---|
[561] | 890 | QString _text = text;
|
---|
| 891 | if (!(flags & Qt::TextLongestVariant)) {
|
---|
| 892 | int posA = 0;
|
---|
| 893 | int posB = _text.indexOf(QLatin1Char('\x9c'));
|
---|
| 894 | while (posB >= 0) {
|
---|
| 895 | QString portion = _text.mid(posA, posB - posA);
|
---|
| 896 | if (size(flags, portion).width() <= width)
|
---|
| 897 | return portion;
|
---|
| 898 | posA = posB + 1;
|
---|
| 899 | posB = _text.indexOf(QLatin1Char('\x9c'), posA);
|
---|
| 900 | }
|
---|
| 901 | _text = _text.mid(posA);
|
---|
| 902 | }
|
---|
| 903 | QStackTextEngine engine(_text, QFont(d.data()));
|
---|
[2] | 904 | return engine.elidedText(mode, width, flags);
|
---|
| 905 | }
|
---|
| 906 |
|
---|
| 907 | /*!
|
---|
| 908 | Returns the distance from the base line to where an underscore
|
---|
| 909 | should be drawn.
|
---|
| 910 |
|
---|
| 911 | \sa overlinePos(), strikeOutPos(), lineWidth()
|
---|
| 912 | */
|
---|
| 913 | int QFontMetrics::underlinePos() const
|
---|
| 914 | {
|
---|
| 915 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
|
---|
| 916 | Q_ASSERT(engine != 0);
|
---|
| 917 | return qRound(engine->underlinePosition());
|
---|
| 918 | }
|
---|
| 919 |
|
---|
| 920 | /*!
|
---|
| 921 | Returns the distance from the base line to where an overline
|
---|
| 922 | should be drawn.
|
---|
| 923 |
|
---|
| 924 | \sa underlinePos(), strikeOutPos(), lineWidth()
|
---|
| 925 | */
|
---|
| 926 | int QFontMetrics::overlinePos() const
|
---|
| 927 | {
|
---|
| 928 | return ascent() + 1;
|
---|
| 929 | }
|
---|
| 930 |
|
---|
| 931 | /*!
|
---|
| 932 | Returns the distance from the base line to where the strikeout
|
---|
| 933 | line should be drawn.
|
---|
| 934 |
|
---|
| 935 | \sa underlinePos(), overlinePos(), lineWidth()
|
---|
| 936 | */
|
---|
| 937 | int QFontMetrics::strikeOutPos() const
|
---|
| 938 | {
|
---|
| 939 | int pos = ascent() / 3;
|
---|
| 940 | return pos > 0 ? pos : 1;
|
---|
| 941 | }
|
---|
| 942 |
|
---|
| 943 | /*!
|
---|
| 944 | Returns the width of the underline and strikeout lines, adjusted
|
---|
| 945 | for the point size of the font.
|
---|
| 946 |
|
---|
| 947 | \sa underlinePos(), overlinePos(), strikeOutPos()
|
---|
| 948 | */
|
---|
| 949 | int QFontMetrics::lineWidth() const
|
---|
| 950 | {
|
---|
| 951 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
|
---|
| 952 | Q_ASSERT(engine != 0);
|
---|
| 953 | return qRound(engine->lineThickness());
|
---|
| 954 | }
|
---|
| 955 |
|
---|
| 956 |
|
---|
| 957 |
|
---|
| 958 |
|
---|
| 959 | /*****************************************************************************
|
---|
| 960 | QFontMetricsF member functions
|
---|
| 961 | *****************************************************************************/
|
---|
| 962 |
|
---|
| 963 | /*!
|
---|
| 964 | \class QFontMetricsF
|
---|
| 965 | \reentrant
|
---|
| 966 |
|
---|
| 967 | \brief The QFontMetricsF class provides font metrics information.
|
---|
| 968 |
|
---|
[561] | 969 | \ingroup painting
|
---|
[2] | 970 | \ingroup shared
|
---|
| 971 |
|
---|
| 972 | QFontMetricsF functions calculate the size of characters and
|
---|
| 973 | strings for a given font. You can construct a QFontMetricsF object
|
---|
| 974 | with an existing QFont to obtain metrics for that font. If the
|
---|
| 975 | font is changed later, the font metrics object is \e not updated.
|
---|
| 976 |
|
---|
| 977 | Once created, the object provides functions to access the
|
---|
| 978 | individual metrics of the font, its characters, and for strings
|
---|
| 979 | rendered in the font.
|
---|
| 980 |
|
---|
| 981 | There are several functions that operate on the font: ascent(),
|
---|
| 982 | descent(), height(), leading() and lineSpacing() return the basic
|
---|
| 983 | size properties of the font. The underlinePos(), overlinePos(),
|
---|
| 984 | strikeOutPos() and lineWidth() functions, return the properties of
|
---|
| 985 | the line that underlines, overlines or strikes out the
|
---|
| 986 | characters. These functions are all fast.
|
---|
| 987 |
|
---|
| 988 | There are also some functions that operate on the set of glyphs in
|
---|
| 989 | the font: minLeftBearing(), minRightBearing() and maxWidth().
|
---|
| 990 | These are by necessity slow, and we recommend avoiding them if
|
---|
| 991 | possible.
|
---|
| 992 |
|
---|
| 993 | For each character, you can get its width(), leftBearing() and
|
---|
| 994 | rightBearing() and find out whether it is in the font using
|
---|
| 995 | inFont(). You can also treat the character as a string, and use
|
---|
| 996 | the string functions on it.
|
---|
| 997 |
|
---|
| 998 | The string functions include width(), to return the width of a
|
---|
| 999 | string in pixels (or points, for a printer), boundingRect(), to
|
---|
| 1000 | return a rectangle large enough to contain the rendered string,
|
---|
| 1001 | and size(), to return the size of that rectangle.
|
---|
| 1002 |
|
---|
| 1003 | Example:
|
---|
| 1004 | \snippet doc/src/snippets/code/src_gui_text_qfontmetrics.cpp 1
|
---|
| 1005 |
|
---|
| 1006 | \sa QFont QFontInfo QFontDatabase
|
---|
| 1007 | */
|
---|
| 1008 |
|
---|
| 1009 | /*!
|
---|
| 1010 | \since 4.2
|
---|
| 1011 |
|
---|
| 1012 | Constructs a font metrics object with floating point precision
|
---|
| 1013 | from the given \a fontMetrics object.
|
---|
| 1014 | */
|
---|
| 1015 | QFontMetricsF::QFontMetricsF(const QFontMetrics &fontMetrics)
|
---|
[561] | 1016 | : d(fontMetrics.d.data())
|
---|
[2] | 1017 | {
|
---|
| 1018 | }
|
---|
| 1019 |
|
---|
| 1020 | /*!
|
---|
| 1021 | \since 4.2
|
---|
| 1022 |
|
---|
| 1023 | Assigns \a other to this object.
|
---|
| 1024 | */
|
---|
| 1025 | QFontMetricsF &QFontMetricsF::operator=(const QFontMetrics &other)
|
---|
| 1026 | {
|
---|
[561] | 1027 | d = other.d.data();
|
---|
[2] | 1028 | return *this;
|
---|
| 1029 | }
|
---|
| 1030 |
|
---|
| 1031 | /*!
|
---|
| 1032 | Constructs a font metrics object for \a font.
|
---|
| 1033 |
|
---|
| 1034 | The font metrics will be compatible with the paintdevice used to
|
---|
| 1035 | create \a font.
|
---|
| 1036 |
|
---|
| 1037 | The font metrics object holds the information for the font that is
|
---|
| 1038 | passed in the constructor at the time it is created, and is not
|
---|
| 1039 | updated if the font's attributes are changed later.
|
---|
| 1040 |
|
---|
| 1041 | Use QFontMetricsF(const QFont &, QPaintDevice *) to get the font
|
---|
| 1042 | metrics that are compatible with a certain paint device.
|
---|
| 1043 | */
|
---|
| 1044 | QFontMetricsF::QFontMetricsF(const QFont &font)
|
---|
[561] | 1045 | : d(font.d.data())
|
---|
[2] | 1046 | {
|
---|
| 1047 | }
|
---|
| 1048 |
|
---|
| 1049 | /*!
|
---|
| 1050 | Constructs a font metrics object for \a font and \a paintdevice.
|
---|
| 1051 |
|
---|
| 1052 | The font metrics will be compatible with the paintdevice passed.
|
---|
| 1053 | If the \a paintdevice is 0, the metrics will be screen-compatible,
|
---|
| 1054 | ie. the metrics you get if you use the font for drawing text on a
|
---|
| 1055 | \link QWidget widgets\endlink or \link QPixmap pixmaps\endlink,
|
---|
| 1056 | not on a QPicture or QPrinter.
|
---|
| 1057 |
|
---|
| 1058 | The font metrics object holds the information for the font that is
|
---|
| 1059 | passed in the constructor at the time it is created, and is not
|
---|
| 1060 | updated if the font's attributes are changed later.
|
---|
| 1061 | */
|
---|
| 1062 | QFontMetricsF::QFontMetricsF(const QFont &font, QPaintDevice *paintdevice)
|
---|
| 1063 | {
|
---|
| 1064 | int dpi = paintdevice ? paintdevice->logicalDpiY() : qt_defaultDpi();
|
---|
| 1065 | #ifdef Q_WS_X11
|
---|
| 1066 | const QX11Info *info = qt_x11Info(paintdevice);
|
---|
| 1067 | int screen = info ? info->screen() : 0;
|
---|
| 1068 | #else
|
---|
| 1069 | const int screen = 0;
|
---|
| 1070 | #endif
|
---|
| 1071 | if (font.d->dpi != dpi || font.d->screen != screen ) {
|
---|
| 1072 | d = new QFontPrivate(*font.d);
|
---|
| 1073 | d->dpi = dpi;
|
---|
| 1074 | d->screen = screen;
|
---|
| 1075 | } else {
|
---|
[561] | 1076 | d = font.d.data();
|
---|
[2] | 1077 | }
|
---|
| 1078 |
|
---|
| 1079 | }
|
---|
| 1080 |
|
---|
| 1081 | /*!
|
---|
| 1082 | Constructs a copy of \a fm.
|
---|
| 1083 | */
|
---|
| 1084 | QFontMetricsF::QFontMetricsF(const QFontMetricsF &fm)
|
---|
[561] | 1085 | : d(fm.d.data())
|
---|
| 1086 | {
|
---|
| 1087 | }
|
---|
[2] | 1088 |
|
---|
| 1089 | /*!
|
---|
| 1090 | Destroys the font metrics object and frees all allocated
|
---|
| 1091 | resources.
|
---|
| 1092 | */
|
---|
| 1093 | QFontMetricsF::~QFontMetricsF()
|
---|
| 1094 | {
|
---|
| 1095 | }
|
---|
| 1096 |
|
---|
| 1097 | /*!
|
---|
| 1098 | Assigns the font metrics \a fm to this font metrics object.
|
---|
| 1099 | */
|
---|
| 1100 | QFontMetricsF &QFontMetricsF::operator=(const QFontMetricsF &fm)
|
---|
| 1101 | {
|
---|
[561] | 1102 | d = fm.d.data();
|
---|
[2] | 1103 | return *this;
|
---|
| 1104 | }
|
---|
| 1105 |
|
---|
| 1106 | /*!
|
---|
| 1107 | \overload
|
---|
| 1108 | Returns true if the font metrics are equal to the \a other font
|
---|
| 1109 | metrics; otherwise returns false.
|
---|
| 1110 |
|
---|
| 1111 | Two font metrics are considered equal if they were constructed from the
|
---|
| 1112 | same QFont and the paint devices they were constructed for are
|
---|
| 1113 | considered to be compatible.
|
---|
| 1114 | */
|
---|
| 1115 | bool QFontMetricsF::operator ==(const QFontMetricsF &other) const
|
---|
| 1116 | {
|
---|
| 1117 | return d == other.d;
|
---|
| 1118 | }
|
---|
| 1119 |
|
---|
| 1120 | /*!
|
---|
| 1121 | Returns true if the font metrics are equal to the \a other font
|
---|
| 1122 | metrics; otherwise returns false.
|
---|
| 1123 |
|
---|
| 1124 | Two font metrics are considered equal if they were constructed from the
|
---|
| 1125 | same QFont and the paint devices they were constructed for are
|
---|
| 1126 | considered to be compatible.
|
---|
| 1127 | */
|
---|
| 1128 | bool QFontMetricsF::operator ==(const QFontMetricsF &other)
|
---|
| 1129 | {
|
---|
| 1130 | return d == other.d;
|
---|
| 1131 | }
|
---|
| 1132 |
|
---|
| 1133 | /*!
|
---|
| 1134 | \fn bool QFontMetricsF::operator!=(const QFontMetricsF &other)
|
---|
| 1135 |
|
---|
| 1136 | Returns true if the font metrics are not equal to the \a other font
|
---|
| 1137 | metrics; otherwise returns false.
|
---|
| 1138 |
|
---|
| 1139 | \sa operator==()
|
---|
| 1140 | */
|
---|
| 1141 |
|
---|
| 1142 | /*!
|
---|
| 1143 | \fn bool QFontMetricsF::operator !=(const QFontMetricsF &other) const
|
---|
| 1144 | \overload
|
---|
| 1145 |
|
---|
| 1146 | Returns true if the font metrics are not equal to the \a other font
|
---|
| 1147 | metrics; otherwise returns false.
|
---|
| 1148 |
|
---|
| 1149 | \sa operator==()
|
---|
| 1150 | */
|
---|
| 1151 |
|
---|
| 1152 | /*!
|
---|
| 1153 | Returns the ascent of the font.
|
---|
| 1154 |
|
---|
| 1155 | The ascent of a font is the distance from the baseline to the
|
---|
| 1156 | highest position characters extend to. In practice, some font
|
---|
| 1157 | designers break this rule, e.g. when they put more than one accent
|
---|
| 1158 | on top of a character, or to accommodate an unusual character in
|
---|
| 1159 | an exotic language, so it is possible (though rare) that this
|
---|
| 1160 | value will be too small.
|
---|
| 1161 |
|
---|
| 1162 | \sa descent()
|
---|
| 1163 | */
|
---|
| 1164 | qreal QFontMetricsF::ascent() const
|
---|
| 1165 | {
|
---|
| 1166 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
|
---|
| 1167 | Q_ASSERT(engine != 0);
|
---|
| 1168 | return engine->ascent().toReal();
|
---|
| 1169 | }
|
---|
| 1170 |
|
---|
| 1171 |
|
---|
| 1172 | /*!
|
---|
| 1173 | Returns the descent of the font.
|
---|
| 1174 |
|
---|
| 1175 | The descent is the distance from the base line to the lowest point
|
---|
| 1176 | characters extend to. (Note that this is different from X, which
|
---|
| 1177 | adds 1 pixel.) In practice, some font designers break this rule,
|
---|
| 1178 | e.g. to accommodate an unusual character in an exotic language, so
|
---|
| 1179 | it is possible (though rare) that this value will be too small.
|
---|
| 1180 |
|
---|
| 1181 | \sa ascent()
|
---|
| 1182 | */
|
---|
| 1183 | qreal QFontMetricsF::descent() const
|
---|
| 1184 | {
|
---|
| 1185 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
|
---|
| 1186 | Q_ASSERT(engine != 0);
|
---|
| 1187 | return engine->descent().toReal();
|
---|
| 1188 | }
|
---|
| 1189 |
|
---|
| 1190 | /*!
|
---|
| 1191 | Returns the height of the font.
|
---|
| 1192 |
|
---|
| 1193 | This is always equal to ascent()+descent()+1 (the 1 is for the
|
---|
| 1194 | base line).
|
---|
| 1195 |
|
---|
| 1196 | \sa leading(), lineSpacing()
|
---|
| 1197 | */
|
---|
| 1198 | qreal QFontMetricsF::height() const
|
---|
| 1199 | {
|
---|
| 1200 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
|
---|
| 1201 | Q_ASSERT(engine != 0);
|
---|
| 1202 |
|
---|
| 1203 | return (engine->ascent() + engine->descent() + 1).toReal();
|
---|
| 1204 | }
|
---|
| 1205 |
|
---|
| 1206 | /*!
|
---|
| 1207 | Returns the leading of the font.
|
---|
| 1208 |
|
---|
| 1209 | This is the natural inter-line spacing.
|
---|
| 1210 |
|
---|
| 1211 | \sa height(), lineSpacing()
|
---|
| 1212 | */
|
---|
| 1213 | qreal QFontMetricsF::leading() const
|
---|
| 1214 | {
|
---|
| 1215 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
|
---|
| 1216 | Q_ASSERT(engine != 0);
|
---|
| 1217 | return engine->leading().toReal();
|
---|
| 1218 | }
|
---|
| 1219 |
|
---|
| 1220 | /*!
|
---|
| 1221 | Returns the distance from one base line to the next.
|
---|
| 1222 |
|
---|
| 1223 | This value is always equal to leading()+height().
|
---|
| 1224 |
|
---|
| 1225 | \sa height(), leading()
|
---|
| 1226 | */
|
---|
| 1227 | qreal QFontMetricsF::lineSpacing() const
|
---|
| 1228 | {
|
---|
| 1229 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
|
---|
| 1230 | Q_ASSERT(engine != 0);
|
---|
| 1231 | return (engine->leading() + engine->ascent() + engine->descent() + 1).toReal();
|
---|
| 1232 | }
|
---|
| 1233 |
|
---|
| 1234 | /*!
|
---|
| 1235 | Returns the minimum left bearing of the font.
|
---|
| 1236 |
|
---|
| 1237 | This is the smallest leftBearing(char) of all characters in the
|
---|
| 1238 | font.
|
---|
| 1239 |
|
---|
| 1240 | Note that this function can be very slow if the font is large.
|
---|
| 1241 |
|
---|
| 1242 | \sa minRightBearing(), leftBearing()
|
---|
| 1243 | */
|
---|
| 1244 | qreal QFontMetricsF::minLeftBearing() const
|
---|
| 1245 | {
|
---|
| 1246 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
|
---|
| 1247 | Q_ASSERT(engine != 0);
|
---|
| 1248 | return engine->minLeftBearing();
|
---|
| 1249 | }
|
---|
| 1250 |
|
---|
| 1251 | /*!
|
---|
| 1252 | Returns the minimum right bearing of the font.
|
---|
| 1253 |
|
---|
| 1254 | This is the smallest rightBearing(char) of all characters in the
|
---|
| 1255 | font.
|
---|
| 1256 |
|
---|
| 1257 | Note that this function can be very slow if the font is large.
|
---|
| 1258 |
|
---|
| 1259 | \sa minLeftBearing(), rightBearing()
|
---|
| 1260 | */
|
---|
| 1261 | qreal QFontMetricsF::minRightBearing() const
|
---|
| 1262 | {
|
---|
| 1263 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
|
---|
| 1264 | Q_ASSERT(engine != 0);
|
---|
| 1265 | return engine->minRightBearing();
|
---|
| 1266 | }
|
---|
| 1267 |
|
---|
| 1268 | /*!
|
---|
| 1269 | Returns the width of the widest character in the font.
|
---|
| 1270 | */
|
---|
| 1271 | qreal QFontMetricsF::maxWidth() const
|
---|
| 1272 | {
|
---|
| 1273 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
|
---|
| 1274 | Q_ASSERT(engine != 0);
|
---|
| 1275 | return engine->maxCharWidth();
|
---|
| 1276 | }
|
---|
| 1277 |
|
---|
| 1278 | /*!
|
---|
| 1279 | Returns the 'x' height of the font. This is often but not always
|
---|
| 1280 | the same as the height of the character 'x'.
|
---|
| 1281 | */
|
---|
| 1282 | qreal QFontMetricsF::xHeight() const
|
---|
| 1283 | {
|
---|
| 1284 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
|
---|
| 1285 | Q_ASSERT(engine != 0);
|
---|
| 1286 | if (d->capital == QFont::SmallCaps)
|
---|
| 1287 | return d->smallCapsFontPrivate()->engineForScript(QUnicodeTables::Common)->ascent().toReal();
|
---|
| 1288 | return engine->xHeight().toReal();
|
---|
| 1289 | }
|
---|
| 1290 |
|
---|
| 1291 | /*!
|
---|
| 1292 | \since 4.2
|
---|
| 1293 |
|
---|
| 1294 | Returns the average width of glyphs in the font.
|
---|
| 1295 | */
|
---|
| 1296 | qreal QFontMetricsF::averageCharWidth() const
|
---|
| 1297 | {
|
---|
| 1298 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
|
---|
| 1299 | Q_ASSERT(engine != 0);
|
---|
| 1300 | return engine->averageCharWidth().toReal();
|
---|
| 1301 | }
|
---|
| 1302 |
|
---|
| 1303 | /*!
|
---|
| 1304 | Returns true if character \a ch is a valid character in the font;
|
---|
| 1305 | otherwise returns false.
|
---|
| 1306 | */
|
---|
| 1307 | bool QFontMetricsF::inFont(QChar ch) const
|
---|
| 1308 | {
|
---|
| 1309 | const int script = QUnicodeTables::script(ch);
|
---|
| 1310 | QFontEngine *engine = d->engineForScript(script);
|
---|
| 1311 | Q_ASSERT(engine != 0);
|
---|
| 1312 | if (engine->type() == QFontEngine::Box)
|
---|
| 1313 | return false;
|
---|
| 1314 | return engine->canRender(&ch, 1);
|
---|
| 1315 | }
|
---|
| 1316 |
|
---|
| 1317 | /*!
|
---|
| 1318 | Returns the left bearing of character \a ch in the font.
|
---|
| 1319 |
|
---|
| 1320 | The left bearing is the right-ward distance of the left-most pixel
|
---|
| 1321 | of the character from the logical origin of the character. This
|
---|
| 1322 | value is negative if the pixels of the character extend to the
|
---|
| 1323 | left of the logical origin.
|
---|
| 1324 |
|
---|
| 1325 | See width(QChar) for a graphical description of this metric.
|
---|
| 1326 |
|
---|
| 1327 | \sa rightBearing(), minLeftBearing(), width()
|
---|
| 1328 | */
|
---|
| 1329 | qreal QFontMetricsF::leftBearing(QChar ch) const
|
---|
| 1330 | {
|
---|
| 1331 | const int script = QUnicodeTables::script(ch);
|
---|
| 1332 | QFontEngine *engine;
|
---|
| 1333 | if (d->capital == QFont::SmallCaps && ch.isLower())
|
---|
| 1334 | engine = d->smallCapsFontPrivate()->engineForScript(script);
|
---|
| 1335 | else
|
---|
| 1336 | engine = d->engineForScript(script);
|
---|
| 1337 | Q_ASSERT(engine != 0);
|
---|
| 1338 | if (engine->type() == QFontEngine::Box)
|
---|
| 1339 | return 0;
|
---|
| 1340 |
|
---|
| 1341 | d->alterCharForCapitalization(ch);
|
---|
| 1342 |
|
---|
| 1343 | QGlyphLayoutArray<10> glyphs;
|
---|
| 1344 | int nglyphs = 9;
|
---|
| 1345 | engine->stringToCMap(&ch, 1, &glyphs, &nglyphs, 0);
|
---|
| 1346 | // ### can nglyphs != 1 happen at all? Not currently I think
|
---|
[769] | 1347 | qreal lb;
|
---|
| 1348 | engine->getGlyphBearings(glyphs.glyphs[0], &lb);
|
---|
| 1349 | return lb;
|
---|
[2] | 1350 | }
|
---|
| 1351 |
|
---|
| 1352 | /*!
|
---|
| 1353 | Returns the right bearing of character \a ch in the font.
|
---|
| 1354 |
|
---|
| 1355 | The right bearing is the left-ward distance of the right-most
|
---|
| 1356 | pixel of the character from the logical origin of a subsequent
|
---|
| 1357 | character. This value is negative if the pixels of the character
|
---|
| 1358 | extend to the right of the width() of the character.
|
---|
| 1359 |
|
---|
| 1360 | See width() for a graphical description of this metric.
|
---|
| 1361 |
|
---|
| 1362 | \sa leftBearing(), minRightBearing(), width()
|
---|
| 1363 | */
|
---|
| 1364 | qreal QFontMetricsF::rightBearing(QChar ch) const
|
---|
| 1365 | {
|
---|
| 1366 | const int script = QUnicodeTables::script(ch);
|
---|
| 1367 | QFontEngine *engine;
|
---|
| 1368 | if (d->capital == QFont::SmallCaps && ch.isLower())
|
---|
| 1369 | engine = d->smallCapsFontPrivate()->engineForScript(script);
|
---|
| 1370 | else
|
---|
| 1371 | engine = d->engineForScript(script);
|
---|
| 1372 | Q_ASSERT(engine != 0);
|
---|
| 1373 | if (engine->type() == QFontEngine::Box)
|
---|
| 1374 | return 0;
|
---|
| 1375 |
|
---|
| 1376 | d->alterCharForCapitalization(ch);
|
---|
| 1377 |
|
---|
| 1378 | QGlyphLayoutArray<10> glyphs;
|
---|
| 1379 | int nglyphs = 9;
|
---|
| 1380 | engine->stringToCMap(&ch, 1, &glyphs, &nglyphs, 0);
|
---|
| 1381 | // ### can nglyphs != 1 happen at all? Not currently I think
|
---|
[769] | 1382 | qreal rb;
|
---|
| 1383 | engine->getGlyphBearings(glyphs.glyphs[0], 0, &rb);
|
---|
| 1384 | return rb;
|
---|
| 1385 |
|
---|
[2] | 1386 | }
|
---|
| 1387 |
|
---|
| 1388 | /*!
|
---|
| 1389 | Returns the width in pixels of the characters in the given \a text.
|
---|
| 1390 |
|
---|
| 1391 | Note that this value is \e not equal to the width returned by
|
---|
| 1392 | boundingRect().width() because boundingRect() returns a rectangle
|
---|
| 1393 | describing the pixels this string will cover whereas width()
|
---|
| 1394 | returns the distance to where the next string should be drawn.
|
---|
| 1395 |
|
---|
| 1396 | \sa boundingRect()
|
---|
| 1397 | */
|
---|
| 1398 | qreal QFontMetricsF::width(const QString &text) const
|
---|
| 1399 | {
|
---|
[561] | 1400 | int pos = text.indexOf(QLatin1Char('\x9c'));
|
---|
| 1401 | int len = (pos != -1) ? pos : text.length();
|
---|
| 1402 |
|
---|
[846] | 1403 | QStackTextEngine layout(text, d.data());
|
---|
[2] | 1404 | layout.ignoreBidi = true;
|
---|
| 1405 | layout.itemize();
|
---|
[561] | 1406 | return layout.width(0, len).toReal();
|
---|
[2] | 1407 | }
|
---|
| 1408 |
|
---|
| 1409 | /*!
|
---|
| 1410 | \overload
|
---|
| 1411 |
|
---|
| 1412 | \img bearings.png Bearings
|
---|
| 1413 |
|
---|
| 1414 | Returns the logical width of character \a ch in pixels. This is a
|
---|
| 1415 | distance appropriate for drawing a subsequent character after \a
|
---|
| 1416 | ch.
|
---|
| 1417 |
|
---|
| 1418 | Some of the metrics are described in the image to the right. The
|
---|
| 1419 | central dark rectangles cover the logical width() of each
|
---|
| 1420 | character. The outer pale rectangles cover the leftBearing() and
|
---|
| 1421 | rightBearing() of each character. Notice that the bearings of "f"
|
---|
| 1422 | in this particular font are both negative, while the bearings of
|
---|
| 1423 | "o" are both positive.
|
---|
| 1424 |
|
---|
| 1425 | \warning This function will produce incorrect results for Arabic
|
---|
| 1426 | characters or non-spacing marks in the middle of a string, as the
|
---|
| 1427 | glyph shaping and positioning of marks that happens when
|
---|
[561] | 1428 | processing strings cannot be taken into account. When implementing
|
---|
| 1429 | an interactive text control, use QTextLayout instead.
|
---|
[2] | 1430 |
|
---|
| 1431 | \sa boundingRect()
|
---|
| 1432 | */
|
---|
| 1433 | qreal QFontMetricsF::width(QChar ch) const
|
---|
| 1434 | {
|
---|
| 1435 | if (QChar::category(ch.unicode()) == QChar::Mark_NonSpacing)
|
---|
| 1436 | return 0.;
|
---|
| 1437 |
|
---|
| 1438 | const int script = QUnicodeTables::script(ch);
|
---|
| 1439 | QFontEngine *engine;
|
---|
| 1440 | if (d->capital == QFont::SmallCaps && ch.isLower())
|
---|
| 1441 | engine = d->smallCapsFontPrivate()->engineForScript(script);
|
---|
| 1442 | else
|
---|
| 1443 | engine = d->engineForScript(script);
|
---|
| 1444 | Q_ASSERT(engine != 0);
|
---|
| 1445 |
|
---|
| 1446 | d->alterCharForCapitalization(ch);
|
---|
| 1447 |
|
---|
| 1448 | QGlyphLayoutArray<8> glyphs;
|
---|
| 1449 | int nglyphs = 7;
|
---|
| 1450 | engine->stringToCMap(&ch, 1, &glyphs, &nglyphs, 0);
|
---|
| 1451 | return glyphs.advances_x[0].toReal();
|
---|
| 1452 | }
|
---|
| 1453 |
|
---|
| 1454 | /*!
|
---|
| 1455 | Returns the bounding rectangle of the characters in the string
|
---|
| 1456 | specified by \a text. The bounding rectangle always covers at least
|
---|
| 1457 | the set of pixels the text would cover if drawn at (0, 0).
|
---|
| 1458 |
|
---|
| 1459 | Note that the bounding rectangle may extend to the left of (0, 0),
|
---|
| 1460 | e.g. for italicized fonts, and that the width of the returned
|
---|
| 1461 | rectangle might be different than what the width() method returns.
|
---|
| 1462 |
|
---|
| 1463 | If you want to know the advance width of the string (to layout
|
---|
| 1464 | a set of strings next to each other), use width() instead.
|
---|
| 1465 |
|
---|
| 1466 | Newline characters are processed as normal characters, \e not as
|
---|
| 1467 | linebreaks.
|
---|
| 1468 |
|
---|
| 1469 | The height of the bounding rectangle is at least as large as the
|
---|
| 1470 | value returned height().
|
---|
| 1471 |
|
---|
| 1472 | \sa width(), height(), QPainter::boundingRect()
|
---|
| 1473 | */
|
---|
| 1474 | QRectF QFontMetricsF::boundingRect(const QString &text) const
|
---|
| 1475 | {
|
---|
| 1476 | int len = text.length();
|
---|
| 1477 | if (len == 0)
|
---|
| 1478 | return QRectF();
|
---|
| 1479 |
|
---|
[846] | 1480 | QStackTextEngine layout(text, d.data());
|
---|
[2] | 1481 | layout.ignoreBidi = true;
|
---|
| 1482 | layout.itemize();
|
---|
| 1483 | glyph_metrics_t gm = layout.boundingBox(0, len);
|
---|
| 1484 | return QRectF(gm.x.toReal(), gm.y.toReal(),
|
---|
| 1485 | gm.width.toReal(), gm.height.toReal());
|
---|
| 1486 | }
|
---|
| 1487 |
|
---|
| 1488 | /*!
|
---|
| 1489 | Returns the bounding rectangle of the character \a ch relative to
|
---|
| 1490 | the left-most point on the base line.
|
---|
| 1491 |
|
---|
| 1492 | Note that the bounding rectangle may extend to the left of (0, 0),
|
---|
| 1493 | e.g. for italicized fonts, and that the text output may cover \e
|
---|
| 1494 | all pixels in the bounding rectangle.
|
---|
| 1495 |
|
---|
| 1496 | Note that the rectangle usually extends both above and below the
|
---|
| 1497 | base line.
|
---|
| 1498 |
|
---|
| 1499 | \sa width()
|
---|
| 1500 | */
|
---|
| 1501 | QRectF QFontMetricsF::boundingRect(QChar ch) const
|
---|
| 1502 | {
|
---|
| 1503 | const int script = QUnicodeTables::script(ch);
|
---|
| 1504 | QFontEngine *engine;
|
---|
| 1505 | if (d->capital == QFont::SmallCaps && ch.isLower())
|
---|
| 1506 | engine = d->smallCapsFontPrivate()->engineForScript(script);
|
---|
| 1507 | else
|
---|
| 1508 | engine = d->engineForScript(script);
|
---|
| 1509 | Q_ASSERT(engine != 0);
|
---|
| 1510 |
|
---|
| 1511 | d->alterCharForCapitalization(ch);
|
---|
| 1512 |
|
---|
| 1513 | QGlyphLayoutArray<10> glyphs;
|
---|
| 1514 | int nglyphs = 9;
|
---|
| 1515 | engine->stringToCMap(&ch, 1, &glyphs, &nglyphs, 0);
|
---|
| 1516 | glyph_metrics_t gm = engine->boundingBox(glyphs.glyphs[0]);
|
---|
| 1517 | return QRectF(gm.x.toReal(), gm.y.toReal(), gm.width.toReal(), gm.height.toReal());
|
---|
| 1518 | }
|
---|
| 1519 |
|
---|
| 1520 | /*!
|
---|
| 1521 | \overload
|
---|
| 1522 |
|
---|
| 1523 | Returns the bounding rectangle of the characters in the given \a text.
|
---|
| 1524 | This is the set of pixels the text would cover if drawn when constrained
|
---|
| 1525 | to the bounding rectangle specified by \a rect.
|
---|
| 1526 |
|
---|
| 1527 | The \a flags argument is the bitwise OR of the following flags:
|
---|
| 1528 | \list
|
---|
| 1529 | \o Qt::AlignLeft aligns to the left border, except for
|
---|
| 1530 | Arabic and Hebrew where it aligns to the right.
|
---|
| 1531 | \o Qt::AlignRight aligns to the right border, except for
|
---|
| 1532 | Arabic and Hebrew where it aligns to the left.
|
---|
| 1533 | \o Qt::AlignJustify produces justified text.
|
---|
| 1534 | \o Qt::AlignHCenter aligns horizontally centered.
|
---|
| 1535 | \o Qt::AlignTop aligns to the top border.
|
---|
| 1536 | \o Qt::AlignBottom aligns to the bottom border.
|
---|
| 1537 | \o Qt::AlignVCenter aligns vertically centered
|
---|
| 1538 | \o Qt::AlignCenter (== \c{Qt::AlignHCenter | Qt::AlignVCenter})
|
---|
| 1539 | \o Qt::TextSingleLine ignores newline characters in the text.
|
---|
| 1540 | \o Qt::TextExpandTabs expands tabs (see below)
|
---|
[561] | 1541 | \o Qt::TextShowMnemonic interprets "&x" as \underline{x}; i.e., underlined.
|
---|
[2] | 1542 | \o Qt::TextWordWrap breaks the text to fit the rectangle.
|
---|
| 1543 | \endlist
|
---|
| 1544 |
|
---|
| 1545 | Qt::Horizontal alignment defaults to Qt::AlignLeft and vertical
|
---|
| 1546 | alignment defaults to Qt::AlignTop.
|
---|
| 1547 |
|
---|
| 1548 | If several of the horizontal or several of the vertical alignment
|
---|
| 1549 | flags are set, the resulting alignment is undefined.
|
---|
| 1550 |
|
---|
| 1551 | These flags are defined in \l{Qt::AlignmentFlag}.
|
---|
| 1552 |
|
---|
| 1553 | If Qt::TextExpandTabs is set in \a flags, the following behavior is
|
---|
| 1554 | used to interpret tab characters in the text:
|
---|
| 1555 | \list
|
---|
| 1556 | \o If \a tabArray is non-null, it specifies a 0-terminated sequence of
|
---|
| 1557 | pixel-positions for tabs in the text.
|
---|
| 1558 | \o If \a tabStops is non-zero, it is used as the tab spacing (in pixels).
|
---|
| 1559 | \endlist
|
---|
| 1560 |
|
---|
| 1561 | Note that the bounding rectangle may extend to the left of (0, 0),
|
---|
| 1562 | e.g. for italicized fonts.
|
---|
| 1563 |
|
---|
| 1564 | Newline characters are processed as line breaks.
|
---|
| 1565 |
|
---|
| 1566 | Despite the different actual character heights, the heights of the
|
---|
| 1567 | bounding rectangles of "Yes" and "yes" are the same.
|
---|
| 1568 |
|
---|
| 1569 | The bounding rectangle returned by this function is somewhat larger
|
---|
| 1570 | than that calculated by the simpler boundingRect() function. This
|
---|
| 1571 | function uses the \link minLeftBearing() maximum left \endlink and
|
---|
| 1572 | \link minRightBearing() right \endlink font bearings as is
|
---|
| 1573 | necessary for multi-line text to align correctly. Also,
|
---|
| 1574 | fontHeight() and lineSpacing() are used to calculate the height,
|
---|
| 1575 | rather than individual character heights.
|
---|
| 1576 |
|
---|
| 1577 | \sa width(), QPainter::boundingRect(), Qt::Alignment
|
---|
| 1578 | */
|
---|
| 1579 | QRectF QFontMetricsF::boundingRect(const QRectF &rect, int flags, const QString& text,
|
---|
| 1580 | int tabStops, int *tabArray) const
|
---|
| 1581 | {
|
---|
| 1582 | int tabArrayLen = 0;
|
---|
| 1583 | if (tabArray)
|
---|
| 1584 | while (tabArray[tabArrayLen])
|
---|
| 1585 | tabArrayLen++;
|
---|
| 1586 |
|
---|
| 1587 | QRectF rb;
|
---|
[561] | 1588 | qt_format_text(QFont(d.data()), rect, flags | Qt::TextDontPrint, text, &rb, tabStops, tabArray,
|
---|
[2] | 1589 | tabArrayLen, 0);
|
---|
| 1590 | return rb;
|
---|
| 1591 | }
|
---|
| 1592 |
|
---|
| 1593 | /*!
|
---|
| 1594 | Returns the size in pixels of the characters in the given \a text.
|
---|
| 1595 |
|
---|
| 1596 | The \a flags argument is the bitwise OR of the following flags:
|
---|
| 1597 | \list
|
---|
| 1598 | \o Qt::TextSingleLine ignores newline characters.
|
---|
| 1599 | \o Qt::TextExpandTabs expands tabs (see below)
|
---|
[561] | 1600 | \o Qt::TextShowMnemonic interprets "&x" as \underline{x}; i.e., underlined.
|
---|
[2] | 1601 | \o Qt::TextWordBreak breaks the text to fit the rectangle.
|
---|
| 1602 | \endlist
|
---|
| 1603 |
|
---|
| 1604 | These flags are defined in \l{Qt::TextFlags}.
|
---|
| 1605 |
|
---|
| 1606 | If Qt::TextExpandTabs is set in \a flags, the following behavior is
|
---|
| 1607 | used to interpret tab characters in the text:
|
---|
| 1608 | \list
|
---|
| 1609 | \o If \a tabArray is non-null, it specifies a 0-terminated sequence of
|
---|
| 1610 | pixel-positions for tabs in the text.
|
---|
| 1611 | \o If \a tabStops is non-zero, it is used as the tab spacing (in pixels).
|
---|
| 1612 | \endlist
|
---|
| 1613 |
|
---|
| 1614 | Newline characters are processed as line breaks.
|
---|
| 1615 |
|
---|
| 1616 | Note: Despite the different actual character heights, the heights of the
|
---|
| 1617 | bounding rectangles of "Yes" and "yes" are the same.
|
---|
| 1618 |
|
---|
| 1619 | \sa boundingRect()
|
---|
| 1620 | */
|
---|
| 1621 | QSizeF QFontMetricsF::size(int flags, const QString &text, int tabStops, int *tabArray) const
|
---|
| 1622 | {
|
---|
[561] | 1623 | return boundingRect(QRectF(), flags | Qt::TextLongestVariant, text, tabStops, tabArray).size();
|
---|
[2] | 1624 | }
|
---|
| 1625 |
|
---|
| 1626 | /*!
|
---|
| 1627 | \since 4.3
|
---|
| 1628 |
|
---|
| 1629 | Returns a tight bounding rectangle around the characters in the
|
---|
| 1630 | string specified by \a text. The bounding rectangle always covers
|
---|
| 1631 | at least the set of pixels the text would cover if drawn at (0,
|
---|
| 1632 | 0).
|
---|
| 1633 |
|
---|
| 1634 | Note that the bounding rectangle may extend to the left of (0, 0),
|
---|
| 1635 | e.g. for italicized fonts, and that the width of the returned
|
---|
| 1636 | rectangle might be different than what the width() method returns.
|
---|
| 1637 |
|
---|
| 1638 | If you want to know the advance width of the string (to layout
|
---|
| 1639 | a set of strings next to each other), use width() instead.
|
---|
| 1640 |
|
---|
| 1641 | Newline characters are processed as normal characters, \e not as
|
---|
| 1642 | linebreaks.
|
---|
| 1643 |
|
---|
| 1644 | \warning Calling this method is very slow on Windows.
|
---|
| 1645 |
|
---|
| 1646 | \sa width(), height(), boundingRect()
|
---|
| 1647 | */
|
---|
| 1648 | QRectF QFontMetricsF::tightBoundingRect(const QString &text) const
|
---|
| 1649 | {
|
---|
| 1650 | if (text.length() == 0)
|
---|
| 1651 | return QRect();
|
---|
| 1652 |
|
---|
[846] | 1653 | QStackTextEngine layout(text, d.data());
|
---|
[2] | 1654 | layout.ignoreBidi = true;
|
---|
| 1655 | layout.itemize();
|
---|
| 1656 | glyph_metrics_t gm = layout.tightBoundingBox(0, text.length());
|
---|
| 1657 | return QRectF(gm.x.toReal(), gm.y.toReal(), gm.width.toReal(), gm.height.toReal());
|
---|
| 1658 | }
|
---|
| 1659 |
|
---|
| 1660 | /*!
|
---|
| 1661 | \since 4.2
|
---|
| 1662 |
|
---|
| 1663 | If the string \a text is wider than \a width, returns an elided
|
---|
| 1664 | version of the string (i.e., a string with "..." in it).
|
---|
| 1665 | Otherwise, returns the original string.
|
---|
| 1666 |
|
---|
| 1667 | The \a mode parameter specifies whether the text is elided on the
|
---|
| 1668 | left (e.g., "...tech"), in the middle (e.g., "Tr...ch"), or on
|
---|
| 1669 | the right (e.g., "Trol...").
|
---|
| 1670 |
|
---|
| 1671 | The \a width is specified in pixels, not characters.
|
---|
| 1672 |
|
---|
| 1673 | The \a flags argument is optional and currently only supports
|
---|
| 1674 | Qt::TextShowMnemonic as value.
|
---|
| 1675 | */
|
---|
| 1676 | QString QFontMetricsF::elidedText(const QString &text, Qt::TextElideMode mode, qreal width, int flags) const
|
---|
| 1677 | {
|
---|
[561] | 1678 | QString _text = text;
|
---|
| 1679 | if (!(flags & Qt::TextLongestVariant)) {
|
---|
| 1680 | int posA = 0;
|
---|
| 1681 | int posB = _text.indexOf(QLatin1Char('\x9c'));
|
---|
| 1682 | while (posB >= 0) {
|
---|
| 1683 | QString portion = _text.mid(posA, posB - posA);
|
---|
| 1684 | if (size(flags, portion).width() <= width)
|
---|
| 1685 | return portion;
|
---|
| 1686 | posA = posB + 1;
|
---|
| 1687 | posB = _text.indexOf(QLatin1Char('\x9c'), posA);
|
---|
| 1688 | }
|
---|
| 1689 | _text = _text.mid(posA);
|
---|
| 1690 | }
|
---|
| 1691 | QStackTextEngine engine(_text, QFont(d.data()));
|
---|
[2] | 1692 | return engine.elidedText(mode, QFixed::fromReal(width), flags);
|
---|
| 1693 | }
|
---|
| 1694 |
|
---|
| 1695 | /*!
|
---|
| 1696 | Returns the distance from the base line to where an underscore
|
---|
| 1697 | should be drawn.
|
---|
| 1698 |
|
---|
| 1699 | \sa overlinePos(), strikeOutPos(), lineWidth()
|
---|
| 1700 | */
|
---|
| 1701 | qreal QFontMetricsF::underlinePos() const
|
---|
| 1702 | {
|
---|
| 1703 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
|
---|
| 1704 | Q_ASSERT(engine != 0);
|
---|
| 1705 | return engine->underlinePosition().toReal();
|
---|
| 1706 | }
|
---|
| 1707 |
|
---|
| 1708 | /*!
|
---|
| 1709 | Returns the distance from the base line to where an overline
|
---|
| 1710 | should be drawn.
|
---|
| 1711 |
|
---|
| 1712 | \sa underlinePos(), strikeOutPos(), lineWidth()
|
---|
| 1713 | */
|
---|
| 1714 | qreal QFontMetricsF::overlinePos() const
|
---|
| 1715 | {
|
---|
| 1716 | return ascent() + 1;
|
---|
| 1717 | }
|
---|
| 1718 |
|
---|
| 1719 | /*!
|
---|
| 1720 | Returns the distance from the base line to where the strikeout
|
---|
| 1721 | line should be drawn.
|
---|
| 1722 |
|
---|
| 1723 | \sa underlinePos(), overlinePos(), lineWidth()
|
---|
| 1724 | */
|
---|
| 1725 | qreal QFontMetricsF::strikeOutPos() const
|
---|
| 1726 | {
|
---|
| 1727 | return ascent() / 3.;
|
---|
| 1728 | }
|
---|
| 1729 |
|
---|
| 1730 | /*!
|
---|
| 1731 | Returns the width of the underline and strikeout lines, adjusted
|
---|
| 1732 | for the point size of the font.
|
---|
| 1733 |
|
---|
| 1734 | \sa underlinePos(), overlinePos(), strikeOutPos()
|
---|
| 1735 | */
|
---|
| 1736 | qreal QFontMetricsF::lineWidth() const
|
---|
| 1737 | {
|
---|
| 1738 | QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
|
---|
| 1739 | Q_ASSERT(engine != 0);
|
---|
| 1740 | return engine->lineThickness().toReal();
|
---|
| 1741 | }
|
---|
| 1742 |
|
---|
| 1743 | /*!
|
---|
| 1744 | \fn QSize QFontMetrics::size(int flags, const QString &text, int len,
|
---|
| 1745 | int tabStops, int *tabArray) const
|
---|
| 1746 | \compat
|
---|
| 1747 |
|
---|
| 1748 | Use the size() function in combination with QString::left()
|
---|
| 1749 | instead.
|
---|
| 1750 |
|
---|
| 1751 | \oldcode
|
---|
| 1752 | QSize size = size(flags, str, len, tabstops, tabarray);
|
---|
| 1753 | \newcode
|
---|
| 1754 | QSize size = size(flags, str.left(len), tabstops, tabarray);
|
---|
| 1755 | \endcode
|
---|
| 1756 | */
|
---|
| 1757 |
|
---|
| 1758 | /*!
|
---|
| 1759 | \fn QRect QFontMetrics::boundingRect(int x, int y, int w, int h, int flags,
|
---|
| 1760 | const QString& text, int len, int tabStops, int *tabArray) const
|
---|
| 1761 | \compat
|
---|
| 1762 |
|
---|
| 1763 | Use the boundingRect() function in combination with
|
---|
| 1764 | QString::left() and a QRect constructor instead.
|
---|
| 1765 |
|
---|
| 1766 | \oldcode
|
---|
| 1767 | QRect rect = boundingRect(x, y, w, h , flags, text, len,
|
---|
| 1768 | tabStops, tabArray);
|
---|
| 1769 | \newcode
|
---|
| 1770 | QRect rect = boundingRect(QRect(x, y, w, h), flags, text.left(len),
|
---|
| 1771 | tabstops, tabarray);
|
---|
| 1772 | \endcode
|
---|
| 1773 |
|
---|
| 1774 | */
|
---|
| 1775 |
|
---|
| 1776 | /*!
|
---|
| 1777 | \fn QRect QFontMetrics::boundingRect(const QString &text, int len) const
|
---|
| 1778 | \compat
|
---|
| 1779 |
|
---|
| 1780 | Use the boundingRect() function in combination with
|
---|
| 1781 | QString::left() instead.
|
---|
| 1782 |
|
---|
| 1783 | \oldcode
|
---|
| 1784 | QRect rect = boundingRect(text, len);
|
---|
| 1785 | \newcode
|
---|
| 1786 | QRect rect = boundingRect(text.left(len));
|
---|
| 1787 | \endcode
|
---|
| 1788 | */
|
---|
| 1789 |
|
---|
| 1790 | QT_END_NAMESPACE
|
---|