source: trunk/doc/src/examples/treemodelcompleter.qdoc@ 624

Last change on this file since 624 was 561, checked in by Dmitry A. Kuminov, 16 years ago

trunk: Merged in qt 4.6.1 sources.
File size: 7.9 KB
Line 
1/****************************************************************************
2**
3** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
4** All rights reserved.
5** Contact: Nokia Corporation (qt-info@nokia.com)
6**
7** This file is part of the documentation of the Qt Toolkit.
8**
9** $QT_BEGIN_LICENSE:LGPL$
10** Commercial Usage
11** Licensees holding valid Qt Commercial licenses may use this file in
12** accordance with the Qt Commercial License Agreement provided with the
13** Software or, alternatively, in accordance with the terms contained in
14** a written agreement between you and Nokia.
15**
16** GNU Lesser General Public License Usage
17** Alternatively, this file may be used under the terms of the GNU Lesser
18** General Public License version 2.1 as published by the Free Software
19** Foundation and appearing in the file LICENSE.LGPL included in the
20** packaging of this file. Please review the following information to
21** ensure the GNU Lesser General Public License version 2.1 requirements
22** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
23**
24** In addition, as a special exception, Nokia gives you certain additional
25** rights. These rights are described in the Nokia Qt LGPL Exception
26** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
27**
28** GNU General Public License Usage
29** Alternatively, this file may be used under the terms of the GNU
30** General Public License version 3.0 as published by the Free Software
31** Foundation and appearing in the file LICENSE.GPL included in the
32** packaging of this file. Please review the following information to
33** ensure the GNU General Public License version 3.0 requirements will be
34** met: http://www.gnu.org/copyleft/gpl.html.
35**
36** If you have questions regarding the use of this file, please contact
37** Nokia at qt-info@nokia.com.
38** $QT_END_LICENSE$
39**
40****************************************************************************/
41
42/*!
43 \example tools/treemodelcompleter
44 \title Tree Model Completer Example
45
46 The Tree Model Completer example shows how to provide completion
47 facilities for a hierarchical model, using a period as the separator
48 to access Child, GrandChild and GrandGrandChild level objects.
49
50 \image treemodelcompleter-example.png
51
52 Similar to the \l{Completer Example}, we provide QComboBox objects to
53 enable selection for completion mode and case sensitivity, as well as
54 a QCheckBox for wrap completions.
55
56 \section1 The Resource File
57
58 The contents of the TreeModelCompleter is read from \e treemodel.txt.
59 This file is embedded within the \e treemodelcompleter.qrc resource file,
60 which contains the following:
61
62 \quotefile examples/tools/treemodelcompleter/treemodelcompleter.qrc
63
64 \section1 TreeModelCompleter Class Definition
65
66 The \c TreeModelCompleter is a subclass of QCompleter with two
67 constructors - one with \a parent as an argument and another with
68 \a parent and \a model as arguments.
69
70 \snippet examples/tools/treemodelcompleter/treemodelcompleter.h 0
71
72 The class reimplements the protected functions
73 \l{QCompleter::splitPath()}{splitPath()} and
74 \l{QCompleter::pathFromIndex()}{pathFromIndex()} to suit a tree model.
75 For more information on customizing QCompleter to suit tree models, refer
76 to \l{QCompleter#Handling Tree Models}{Handling Tree Models}.
77
78 \c TreeModelCompleter also has a separator property which is declared
79 using the Q_PROPERTY() macro. The separator has READ and WRITE attributes
80 and the corresponding functions \c separator() and \c setSeparator(). For
81 more information on Q_PROPERTY(), refer to \l{Qt's Property System}.
82
83 \section1 TreeModelCompleter Class Implementation
84
85 The first constructor constructs a \c TreeModelCompleter object with a
86 parent while the second constructor constructs an object with a parent
87 and a QAbstractItemModel, \a model.
88
89 \snippet examples/tools/treemodelcompleter/treemodelcompleter.cpp 0
90 \codeline
91 \snippet examples/tools/treemodelcompleter/treemodelcompleter.cpp 1
92
93 The \c separator() function is a getter function that returns the
94 separator string.
95
96 \snippet examples/tools/treemodelcompleter/treemodelcompleter.cpp 2
97
98 As mentioned earlier, the \c splitPath() function is reimplemented because
99 the default implementation is more suited to QDirModel or list models. In
100 order for QCompleter to split the path into a list of strings that are
101 matched at each level, we split it using QString::split() with \c sep as its
102 separator.
103
104 \snippet examples/tools/treemodelcompleter/treemodelcompleter.cpp 3
105
106 The \c pathFromIndex() function returns data for the completionRole() for a
107 tree model. This function is reimplemented as its default implementation is
108 more suitable for list models. If there is no separator, we use
109 \l{QCompleter}'s default implementation, otherwise we use the
110 \l{QStringList::prepend()}{prepend()} function to navigate upwards and
111 accumulate the data. The function then returns a QStringList, \c dataList,
112 using a separator to join objects of different levels.
113
114 \snippet examples/tools/treemodelcompleter/treemodelcompleter.cpp 4
115
116 \section1 MainWindow Class Definition
117
118 The \c MainWindow class is a subclass of QMainWindow and implements five
119 custom slots: \c about(), \c changeCase(), \c changeMode(),
120 \c highlight(), and \c updateContentsLabel().
121
122 \snippet examples/tools/treemodelcompleter/mainwindow.h 0
123
124 In addition, the class has two private functions, \c createMenu() and
125 \c modelFromFile(), as well as private instances of QTreeView, QComboBox,
126 QLabel, \c TreeModelCompleter and QLineEdit.
127
128 \snippet examples/tools/treemodelcompleter/mainwindow.h 1
129
130 \section1 MainWindow Class Implementation
131
132 The \c{MainWindow}'s constructor creates a \c MainWindow object with a
133 parent and initializes the \c completer and \c lineEdit. The
134 \c createMenu() function is invoked to set up the "File" menu and "Help"
135 menu. The \c{completer}'s model is set to the QAbstractItemModel obtained
136 from \c modelFromFile(), and the \l{QCompleter::highlighted()}
137 {highlighted()} signal is connected to \c{MainWindow}'s \c highlight()
138 slot.
139
140 \snippet examples/tools/treemodelcompleter/mainwindow.cpp 0
141
142 The QLabel objects \c modelLabel, \c modeLabel and \c caseLabel are
143 instantiated. Also, the QComboBox objects, \c modeCombo and \c caseCombo,
144 are instantiated and populated. By default, the \c{completer}'s mode is
145 "Filtered Popup" and the case is insensitive.
146
147 \snippet examples/tools/treemodelcompleter/mainwindow.cpp 1
148 \codeline
149 \snippet examples/tools/treemodelcompleter/mainwindow.cpp 2
150
151 We use a QGridLayout to place all the objects in the \c MainWindow.
152
153 \snippet examples/tools/treemodelcompleter/mainwindow.cpp 3
154
155 The \c createMenu() function sets up the QAction objects required and
156 adds them to the "File" menu and "Help" menu. The
157 \l{QAction::triggered()}{triggered()} signals from these actions are
158 connected to their respective slots.
159
160 \snippet examples/tools/treemodelcompleter/mainwindow.cpp 4
161
162 The \c changeMode() function accepts an \a index corresponding to the
163 user's choice of completion mode and changes the \c{completer}'s mode
164 accordingly.
165
166 \snippet examples/tools/treemodelcompleter/mainwindow.cpp 5
167
168 The \c about() function provides a brief description on the Tree Model
169 Completer example.
170
171 \snippet examples/tools/treemodelcompleter/mainwindow.cpp 6
172
173 The \c changeCase() function alternates between \l{Qt::CaseSensitive}
174 {Case Sensitive} and \l{Qt::CaseInsensitive}{Case Insensitive} modes,
175 depending on the value of \a cs.
176
177 \snippet examples/tools/treemodelcompleter/mainwindow.cpp 7
178
179 \section1 \c main() Function
180
181 The \c main() function instantiates \c MainWindow and invokes the
182 \l{QWidget::show()}{show()} function to display it.
183
184 \snippet examples/tools/treemodelcompleter/main.cpp 0
185*/
Note: See TracBrowser for help on using the repository browser.