| 1 | /****************************************************************************
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| 2 | ** $Id: qpaintdevicemetrics.cpp 2 2005-11-16 15:49:26Z dmik $
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| 3 | **
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| 4 | ** Implementation of QPaintDeviceMetrics class
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| 5 | **
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| 6 | ** Created : 941109
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| 7 | **
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| 8 | ** Copyright (C) 1992-2000 Trolltech AS. All rights reserved.
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| 9 | **
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| 10 | ** This file is part of the kernel module of the Qt GUI Toolkit.
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| 11 | **
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| 12 | ** This file may be distributed under the terms of the Q Public License
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| 13 | ** as defined by Trolltech AS of Norway and appearing in the file
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| 14 | ** LICENSE.QPL included in the packaging of this file.
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| 15 | **
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| 16 | ** This file may be distributed and/or modified under the terms of the
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| 17 | ** GNU General Public License version 2 as published by the Free Software
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| 18 | ** Foundation and appearing in the file LICENSE.GPL included in the
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| 19 | ** packaging of this file.
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| 20 | **
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| 21 | ** Licensees holding valid Qt Enterprise Edition or Qt Professional Edition
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| 22 | ** licenses may use this file in accordance with the Qt Commercial License
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| 23 | ** Agreement provided with the Software.
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| 24 | **
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| 25 | ** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
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| 26 | ** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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| 27 | **
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| 28 | ** See http://www.trolltech.com/pricing.html or email sales@trolltech.com for
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| 29 | ** information about Qt Commercial License Agreements.
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| 30 | ** See http://www.trolltech.com/qpl/ for QPL licensing information.
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| 31 | ** See http://www.trolltech.com/gpl/ for GPL licensing information.
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| 32 | **
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| 33 | ** Contact info@trolltech.com if any conditions of this licensing are
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| 34 | ** not clear to you.
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| 35 | **
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| 36 | **********************************************************************/
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| 37 |
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| 38 | #include "qpaintdevicemetrics.h"
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| 39 |
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| 40 | /*!
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| 41 | \class QPaintDeviceMetrics qpaintdevicemetrics.h
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| 42 | \brief The QPaintDeviceMetrics class provides information about a
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| 43 | paint device.
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| 44 |
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| 45 | \ingroup graphics
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| 46 | \ingroup images
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| 47 |
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| 48 | Sometimes when drawing graphics it is necessary to obtain
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| 49 | information about the physical characteristics of a paint device.
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| 50 | This class provides the information. For example, to compute the
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| 51 | aspect ratio of a paint device:
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| 52 |
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| 53 | \code
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| 54 | QPaintDeviceMetrics pdm( myWidget );
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| 55 | double aspect = (double)pdm.widthMM() / (double)pdm.heightMM();
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| 56 | \endcode
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| 57 |
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| 58 | QPaintDeviceMetrics contains methods to provide the width and
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| 59 | height of a device in both pixels (width() and height()) and
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| 60 | millimeters (widthMM() and heightMM()), the number of colors the
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| 61 | device supports (numColors()), the number of bit planes (depth()),
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| 62 | and the resolution of the device (logicalDpiX() and
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| 63 | logicalDpiY()).
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| 64 |
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| 65 | It is not always possible for QPaintDeviceMetrics to compute the
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| 66 | values you ask for, particularly for external devices. The
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| 67 | ultimate example is asking for the resolution of of a QPrinter
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| 68 | that is set to "print to file": who knows what printer that file
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| 69 | will end up on?
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| 70 | */
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| 71 |
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| 72 | /*!
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| 73 | Constructs a metric for the paint device \a pd.
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| 74 | */
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| 75 | QPaintDeviceMetrics::QPaintDeviceMetrics( const QPaintDevice *pd )
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| 76 | {
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| 77 | pdev = (QPaintDevice *)pd;
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| 78 | }
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| 79 |
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| 80 |
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| 81 | /*!
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| 82 | \fn int QPaintDeviceMetrics::width() const
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| 83 |
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| 84 | Returns the width of the paint device in default coordinate system
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| 85 | units (e.g. pixels for QPixmap and QWidget).
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| 86 | */
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| 87 |
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| 88 | /*!
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| 89 | \fn int QPaintDeviceMetrics::height() const
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| 90 |
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| 91 | Returns the height of the paint device in default coordinate
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| 92 | system units (e.g. pixels for QPixmap and QWidget).
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| 93 | */
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| 94 |
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| 95 | /*!
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| 96 | \fn int QPaintDeviceMetrics::widthMM() const
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| 97 |
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| 98 | Returns the width of the paint device, measured in millimeters.
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| 99 | */
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| 100 |
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| 101 | /*!
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| 102 | \fn int QPaintDeviceMetrics::heightMM() const
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| 103 |
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| 104 | Returns the height of the paint device, measured in millimeters.
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| 105 | */
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| 106 |
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| 107 | /*!
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| 108 | \fn int QPaintDeviceMetrics::numColors() const
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| 109 |
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| 110 | Returns the number of different colors available for the paint
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| 111 | device. Since this value is an int will not be sufficient to represent
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| 112 | the number of colors on 32 bit displays, in which case INT_MAX is
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| 113 | returned instead.
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| 114 | */
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| 115 |
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| 116 | /*!
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| 117 | \fn int QPaintDeviceMetrics::depth() const
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| 118 |
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| 119 | Returns the bit depth (number of bit planes) of the paint device.
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| 120 | */
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| 121 |
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| 122 | /*!
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| 123 | \fn int QPaintDeviceMetrics::logicalDpiX() const
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| 124 |
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| 125 | Returns the horizontal resolution of the device in dots per inch,
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| 126 | which is used when computing font sizes. For X, this is usually
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| 127 | the same as could be computed from widthMM(), but it varies on
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| 128 | Windows.
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| 129 | */
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| 130 |
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| 131 | /*!
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| 132 | \fn int QPaintDeviceMetrics::logicalDpiY() const
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| 133 |
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| 134 | Returns the vertical resolution of the device in dots per inch,
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| 135 | which is used when computing font sizes. For X, this is usually
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| 136 | the same as could be computed from heightMM(), but it varies on
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| 137 | Windows.
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| 138 | */
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| 139 |
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| 140 | /*!
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| 141 | \fn int QPaintDeviceMetrics::physicalDpiX() const
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| 142 | \internal
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| 143 | */
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| 144 | /*!
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| 145 | \fn int QPaintDeviceMetrics::physicalDpiY() const
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| 146 | \internal
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| 147 | */
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| 148 |
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