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author | Frederik Gladhorn <frederik.gladhorn@digia.com> | 2012-09-18 20:32:53 +0200 |
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committer | The Qt Project <gerrit-noreply@qt-project.org> | 2012-09-21 19:59:06 +0200 |
commit | d16c565ca6a55788435c52ad45647eda67854d80 (patch) | |
tree | 17e2c192b412e4959d422c1691e74ad172601ff7 /examples/widgets/doc/src/windowflags.qdoc | |
parent | 53373bdd9faf343611796e401805327e6de47586 (diff) |
Move opengl/wid/net example docs to proper folders.
Change-Id: I846439a9cf7ad965ed27a00f98dbc4ff97abe73b
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Reviewed-by: Martin Smith <martin.smith@digia.com>
Diffstat (limited to 'examples/widgets/doc/src/windowflags.qdoc')
-rw-r--r-- | examples/widgets/doc/src/windowflags.qdoc | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/examples/widgets/doc/src/windowflags.qdoc b/examples/widgets/doc/src/windowflags.qdoc new file mode 100644 index 0000000000..e85842b30a --- /dev/null +++ b/examples/widgets/doc/src/windowflags.qdoc @@ -0,0 +1,216 @@ +/**************************************************************************** +** +** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/ +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:FDL$ +** GNU Free Documentation License +** Alternatively, this file may be used under the terms of the GNU Free +** Documentation License version 1.3 as published by the Free Software +** Foundation and appearing in the file included in the packaging of +** this file. +** +** Other Usage +** Alternatively, this file may be used in accordance with the terms +** and conditions contained in a signed written agreement between you +** and Nokia. +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! + \example widgets/windowflags + \title Window Flags Example + + The Window Flags example shows how to use the window flags + available in Qt. + + A window flag is either a type or a hint. A type is used to + specify various window-system properties for the widget. A widget + can only have one type, and the default is Qt::Widget. However, a + widget can have zero or more hints. The hints are used to + customize the appearance of top-level windows. + + A widget's flags are stored in a Qt::WindowFlags type which stores + an OR combination of the flags. + + \image windowflags-example.png Screenshot of the Window Flags example + + The example consists of two classes: + + \list + \li \c ControllerWindow is the main application widget that allows + the user to choose among the available window flags, and displays + the effect on a separate preview window. + \li \c PreviewWindow is a custom widget displaying the name of + its currently set window flags in a read-only text editor. + \endlist + + We will start by reviewing the \c ControllerWindow class, then we + will take a look at the \c PreviewWindow class. + + \section1 ControllerWindow Class Definition + + \snippet widgets/windowflags/controllerwindow.h 0 + + The \c ControllerWindow class inherits QWidget. The widget allows + the user to choose among the available window flags, and displays + the effect on a separate preview window. + + We declare a private \c updatePreview() slot to refresh the + preview window whenever the user changes the window flags. + + We also declare several private functions to simplify the + constructor: We call the \c createTypeGroupBox() function to + create a radio button for each available window type, using the + private \c createButton() function, and gather them within a group + box. In a similar way we use the \c createHintsGroupBox() function + to create a check box for each available hint, using the private + \c createCheckBox() function. + + In addition to the various radio buttons and checkboxes, we need + an associated \c PreviewWindow to show the effect of the currently + chosen window flags. + + \image windowflags_controllerwindow.png Screenshot of the Controller Window + + \section1 ControllerWindow Class Implementation + + \snippet widgets/windowflags/controllerwindow.cpp 0 + + In the constructor we first create the preview window. Then we + create the group boxes containing the available window flags using + the private \c createTypeGroupBox() and \c createHintsGroupBox() + functions. In addition we create a \uicontrol Quit button. We put the + button and a stretchable space in a separate layout to make the + button appear in the \c WindowFlag widget's right bottom corner. + + Finally, we add the button's layout and the two goup boxes to a + QVBoxLayout, set the window title and refresh the preview window + using the \c updatePreview() slot. + + \snippet widgets/windowflags/controllerwindow.cpp 1 + \snippet widgets/windowflags/controllerwindow.cpp 2 + + The \c updatePreview() slot is called whenever the user changes + any of the window flags. First we create an empty Qt::WindowFlags + \c flags, then we determine which one of the types that is checked + and add it to \c flags. + + \snippet widgets/windowflags/controllerwindow.cpp 3 + + We also determine which of the hints that are checked, and add + them to \c flags using an OR operator. We use \c flags to set the + window flags for the preview window. + + \snippet widgets/windowflags/controllerwindow.cpp 4 + + We adjust the position of the preview window. The reason we do + that, is that playing around with the window's frame may on some + platforms cause the window's position to be changed behind our + back. If a window is located in the upper left corner of the + screen, parts of the window may not be visible. So we adjust the + widget's position to make sure that, if this happens, the window + is moved within the screen's boundaries. Finally, we call + QWidget::show() to make sure the preview window is visible. + + \omit + \skipto pos + \printuntil /^\}/ + \endomit + + \snippet widgets/windowflags/controllerwindow.cpp 5 + + The private \c createTypeGroupBox() function is called from the + constructor. + + First we create a group box, and then we create a radio button + (using the private \c createRadioButton() function) for each of + the available types among the window flags. We make Qt::Window the + initially applied type. We put the radio buttons into a + QGridLayout and install the layout on the group box. + + We do not include the default Qt::Widget type. The reason is that + it behaves somewhat different than the other types. If the type is + not specified for a widget, and it has no parent, the widget is a + window. However, if it has a parent, it is a standard child + widget. The other types are all top-level windows, and since the + hints only affect top-level windows, we abandon the Qt::Widget + type. + + \snippet widgets/windowflags/controllerwindow.cpp 6 + + The private \c createHintsGroupBox() function is also called from + the constructor. + + Again, the first thing we do is to create a group box. Then we + create a checkbox, using the private \c createCheckBox() function, + for each of the available hints among the window flags. We put the + checkboxes into a QGridLayout and install the layout on the group + box. + + \snippet widgets/windowflags/controllerwindow.cpp 7 + + The private \c createCheckBox() function is called from \c + createHintsGroupBox(). + + We simply create a QCheckBox with the provided text, connect it to + the private \c updatePreview() slot, and return a pointer to the + checkbox. + + \snippet widgets/windowflags/controllerwindow.cpp 8 + + In the private \c createRadioButton() function it is a + QRadioButton we create with the provided text, and connect to the + private \c updatePreview() slot. The function is called from \c + createTypeGroupBox(), and returns a pointer to the button. + + \section1 PreviewWindow Class Definition + + \snippet widgets/windowflags/previewwindow.h 0 + + The \c PreviewWindow class inherits QWidget. It is a custom widget + that displays the names of its currently set window flags in a + read-only text editor. It is also provided with a QPushbutton that + closes the window. + + We reimplement the constructor to create the \uicontrol Close button and + the text editor, and the QWidget::setWindowFlags() function to + display the names of the window flags. + + \image windowflags_previewwindow.png Screenshot of the Preview Window + + \section1 PreviewWindow Class Implementation + + \snippet widgets/windowflags/previewwindow.cpp 0 + + In the constructor, we first create a QTextEdit and make sure that + it is read-only. + + We also prohibit any line wrapping in the text editor using the + QTextEdit::setLineWrapMode() function. The result is that a + horizontal scrollbar appears when a window flag's name exceeds the + width of the editor. This is a reasonable solution since we + construct the displayed text with built-in line breaks. If no line + breaks were guaranteed, using another QTextEdit::LineWrapMode + would perhaps make more sense. + + Then we create the \uicontrol Close button, and put both the widgets + into a QVBoxLayout before we set the window title. + + \snippet widgets/windowflags/previewwindow.cpp 1 + + In our reimplementation of the \c setWindowFlags() function, we + first set the widgets flags using the QWidget::setWindowFlags() + function. Then we run through the available window flags, creating + a text that contains the names of the flags that matches the \c + flags parameter. Finally, we display the text in the widgets text + editor. +*/ |