Contents

• Public Types
• Public Functions
• Static Public Members
• Detailed Description

Detailed Description

TheQDecoration class is a base class for window decorations in Qt for Embedded Linux

Note that this class is non-portable and only available inQt for Embedded Linux.

Qt for Embedded Linux provides window management of top level windows and several ready made decorations (i.e.,Default,Styled andWindows). Custom decorations can be implemented by subclassing theQDecoration class and creating a decoration plugin (derived fromQDecorationPlugin). The default implementation of theQDecorationFactory class will automatically detect the plugin, and load the decoration into the application at run-time using Qt'splugin system. To actually apply a decoration, use theQApplication::qwsSetDecoration() function.

When creating a custom decoration, implement thepaint() function to paint the border and title decoration, and theregion() function to return the regions the decoration occupies. Reimplement theregionClicked() andregionDoubleClicked() functions to respond to mouse clicks (the default implementations responds to (single) clicks on items in a widget's system menu and double clicks on a widget's title).

QDecoration provides theDecorationRegion enum that describes the various regions of the window decoration, and theregionAt() function to determine the region containing a given point. TheQDecoration class also provides theDecorationState enum describing the state of a given region, e.g. whether it is active or not.

In addition, it is possible to build the system menu for a given top level widget using thebuildSysMenu() function; whenever an action in this menu is triggered, themenuTriggered() function is called automatically.

Finally, theQDecoration class provides a couple of static functions,startMove() andstartResize(), which start a move or resize action by making the appropriate decoration region active and grabbing the mouse input.

Member Type Documentation

enum QDecoration::DecorationRegion

This enum describes the various regions of the window decoration.

See alsoregion(),regionAt(), andDecorationState.

enum QDecoration::DecorationState

This enum describes the various states of a decoration region.

See alsopaint() andDecorationRegion.

Member Function Documentation

QDecoration::QDecoration()

Constructs a decoration object.

[virtual]QDecoration::~QDecoration()

Destroys this decoration object.

[virtual]void QDecoration::buildSysMenu(QWidget * widget,QMenu * menu)

Builds the system menu for the given top levelwidget, addingRestore,Move,Size,Minimize,Maximize andClose actions to the givenmenu.

See alsomenuTriggered().

void QDecoration::menuTriggered(QWidget * widget,QAction * action)

This function is called whenever an action in a top level widget's menu is triggered, and simply calls theregionClicked() function passing thewidget andaction parameters as arguments.

See alsobuildSysMenu().

[pure virtual]bool QDecoration::paint(QPainter * painter, constQWidget * widget,int decorationRegion = All,DecorationState state = Normal)

Implement this function to paint the border and title decoration for the specified top levelwidget using the givenpainter and decorationstate. The specifieddecorationRegion is a bitmask of the values described by theDecorationRegion enum.

Note thatQt for Embedded Linux expects this function to return true if any of the widget's decorations are repainted; otherwise it should return false.

See alsoregion().

[pure virtual]QRegion QDecoration::region(constQWidget * widget, constQRect & rectangle,int decorationRegion = All)

Implement this function to return the region specified bydecorationRegion for the given top levelwidget.

Therectangle parameter specifies the rectangle the decoration is wrapped around. ThedecorationRegion is a bitmask of the values described by theDecorationRegion enum.

See alsoregionAt() andpaint().

QRegion QDecoration::region(constQWidget * widget,int decorationRegion = All)

This is an overloaded function.

[virtual]int QDecoration::regionAt(constQWidget * widget, constQPoint & point)

Returns the type of the first region of the specified top levelwidget containing the givenpoint.

The return value is one of theDecorationRegion enum's values. Use theregion() function to retrieve the actual region. If none of the widget's regions contain the point, this function returnsNone.

See alsoregion().

[virtual]void QDecoration::regionClicked(QWidget * widget,int region)

Handles the event that the specifiedregion in the given top levelwidget is activated by a single click (theregion parameter is described using theDecorationRegion enum).

This function is called whenever a region in a top level widget is clicked; the default implementation responds to clicks on items in the system menu, performing the requested actions.

See alsoregionDoubleClicked() andregion().

[virtual]void QDecoration::regionDoubleClicked(QWidget * widget,int region)

Handles the event that the specifiedregion in the given top levelwidget is activated by a double click (the region parameter is described using theDecorationRegion enum).

This function is called whenever a region in a top level widget is double clicked; the default implementation responds to a double click on the widget's title, toggling its size between the maximum and its normal size.

See alsoregionClicked() andregion().

[static]void QDecoration::startMove(QWidget * widget)

Starts to move the given top levelwidget by making itsTitle region active and grabbing the mouse input.

See alsostartResize().

[static]void QDecoration::startResize(QWidget * widget)

Starts to resize the given top levelwidget by making itsBottomRight region active and grabbing the mouse input.

See alsostartMove().