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/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Nokia Corporation (qt-info@nokia.com)
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** This file is part of the documentation of the Qt Toolkit.
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/*!
\example tools/treemodelcompleter
\title Tree Model Completer Example
The Tree Model Completer example shows how to provide completion
facilities for a hierarchical model, using a period as the separator
to access Child, GrandChild and GrandGrandChild level objects.
\image treemodelcompleter-example.png
Similar to the \l{Completer Example}, we provide QComboBox objects to
enable selection for completion mode and case sensitivity, as well as
a QCheckBox for wrap completions.
\section1 The Resource File
The contents of the TreeModelCompleter is read from \e treemodel.txt.
This file is embedded within the \e treemodelcompleter.qrc resource file,
which contains the following:
\quotefile examples/tools/treemodelcompleter/treemodelcompleter.qrc
\section1 TreeModelCompleter Class Definition
The \c TreeModelCompleter is a subclass of QCompleter with two
constructors - one with \a parent as an argument and another with
\a parent and \a model as arguments.
\snippet examples/tools/treemodelcompleter/treemodelcompleter.h 0
The class reimplements the protected functions
\l{QCompleter::splitPath()}{splitPath()} and
\l{QCompleter::pathFromIndex()}{pathFromIndex()} to suit a tree model.
For more information on customizing QCompleter to suit tree models, refer
to \l{QCompleter#Handling Tree Models}{Handling Tree Models}.
\c TreeModelCompleter also has a separator property which is declared
using the Q_PROPERTY() macro. The separator has READ and WRITE attributes
and the corresponding functions \c separator() and \c setSeparator(). For
more information on Q_PROPERTY(), refer to \l{Qt's Property System}.
\section1 TreeModelCompleter Class Implementation
The first constructor constructs a \c TreeModelCompleter object with a
parent while the second constructor constructs an object with a parent
and a QAbstractItemModel, \a model.
\snippet examples/tools/treemodelcompleter/treemodelcompleter.cpp 0
\codeline
\snippet examples/tools/treemodelcompleter/treemodelcompleter.cpp 1
The \c separator() function is a getter function that returns the
separator string.
\snippet examples/tools/treemodelcompleter/treemodelcompleter.cpp 2
As mentioned earlier, the \c splitPath() function is reimplemented because
the default implementation is more suited to QDirModel or list models. In
order for QCompleter to split the path into a list of strings that are
matched at each level, we split it using QString::split() with \c sep as its
separator.
\snippet examples/tools/treemodelcompleter/treemodelcompleter.cpp 3
The \c pathFromIndex() function returns data for the completionRole() for a
tree model. This function is reimplemented as its default implementation is
more suitable for list models. If there is no separator, we use
\l{QCompleter}'s default implementation, otherwise we use the
\l{QStringList::prepend()}{prepend()} function to navigate upwards and
accumulate the data. The function then returns a QStringList, \c dataList,
using a separator to join objects of different levels.
\snippet examples/tools/treemodelcompleter/treemodelcompleter.cpp 4
\section1 MainWindow Class Definition
The \c MainWindow class is a subclass of QMainWindow and implements five
custom slots: \c about(), \c changeCase(), \c changeMode(),
\c highlight(), and \c updateContentsLabel().
\snippet examples/tools/treemodelcompleter/mainwindow.h 0
In addition, the class has two private functions, \c createMenu() and
\c modelFromFile(), as well as private instances of QTreeView, QComboBox,
QLabel, \c TreeModelCompleter and QLineEdit.
\snippet examples/tools/treemodelcompleter/mainwindow.h 1
\section1 MainWindow Class Implementation
The \c{MainWindow}'s constructor creates a \c MainWindow object with a
parent and initializes the \c completer and \c lineEdit. The
\c createMenu() function is invoked to set up the "File" menu and "Help"
menu. The \c{completer}'s model is set to the QAbstractItemModel obtained
from \c modelFromFile(), and the \l{QCompleter::highlighted()}
{highlighted()} signal is connected to \c{MainWindow}'s \c highlight()
slot.
\snippet examples/tools/treemodelcompleter/mainwindow.cpp 0
The QLabel objects \c modelLabel, \c modeLabel and \c caseLabel are
instantiated. Also, the QComboBox objects, \c modeCombo and \c caseCombo,
are instantiated and populated. By default, the \c{completer}'s mode is
"Filtered Popup" and the case is insensitive.
\snippet examples/tools/treemodelcompleter/mainwindow.cpp 1
\codeline
\snippet examples/tools/treemodelcompleter/mainwindow.cpp 2
We use a QGridLayout to place all the objects in the \c MainWindow.
\snippet examples/tools/treemodelcompleter/mainwindow.cpp 3
The \c createMenu() function sets up the QAction objects required and
adds them to the "File" menu and "Help" menu. The
\l{QAction::triggered()}{triggered()} signals from these actions are
connected to their respective slots.
\snippet examples/tools/treemodelcompleter/mainwindow.cpp 4
The \c changeMode() function accepts an \a index corresponding to the
user's choice of completion mode and changes the \c{completer}'s mode
accordingly.
\snippet examples/tools/treemodelcompleter/mainwindow.cpp 5
The \c about() function provides a brief description on the Tree Model
Completer example.
\snippet examples/tools/treemodelcompleter/mainwindow.cpp 6
The \c changeCase() function alternates between \l{Qt::CaseSensitive}
{Case Sensitive} and \l{Qt::CaseInsensitive}{Case Insensitive} modes,
depending on the value of \a cs.
\snippet examples/tools/treemodelcompleter/mainwindow.cpp 7
\section1 \c main() Function
The \c main() function instantiates \c MainWindow and invokes the
\l{QWidget::show()}{show()} function to display it.
\snippet examples/tools/treemodelcompleter/main.cpp 0
*/
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