QDecoration Class Reference
[QtGui module]

Detailed Description

The QDecoration class is a base class for window decorations in Qt for Embedded Linux

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

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

When creating a custom decoration, implement the paint() function to paint the border and title decoration, and the region() function to return the regions the decoration occupies. Reimplement the regionClicked() and regionDoubleClicked() 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 the DecorationRegion enum that describes the various regions of the window decoration, and the regionAt() function to determine the region containing a given point. The QDecoration class also provides the DecorationState 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 the buildSysMenu() function; whenever an action in this menu is triggered, the menuTriggered() function is called automatically.

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

See also QDecorationFactory, QDecorationPlugin, and Qt for Embedded Linux Architecture.

Member Type Documentation

enum QDecoration::DecorationRegion

This enum describes the various regions of the window decoration.

See also region(), regionAt(), and DecorationState.

enum QDecoration::DecorationState

This enum describes the various states of a decoration region.

See also paint() and DecorationRegion.

Member Function Documentation

QDecoration::QDecoration ()

Constructs a decoration object.

QDecoration::~QDecoration ()   [virtual]

Destroys this decoration object.

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

Builds the system menu for the given top level widget, adding Restore, Move, Size, Minimize, Maximize and Close actions to the given menu.

See also menuTriggered().

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 the regionClicked() function passing the widget and action parameters as arguments.

See also buildSysMenu().

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

Implement this function to paint the border and title decoration for the specified top level widget using the given painter and decoration state. The specified decorationRegion is a bitmask of the values described by the DecorationRegion enum.

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

See also region().

QRegion QDecoration::region ( const QWidget * widget, const QRect & rectangle, int decorationRegion = All )   [pure virtual]

Implement this function to return the region specified by decorationRegion for the given top level widget.

The rectangle parameter specifies the rectangle the decoration is wrapped around. The decorationRegion is a bitmask of the values described by the DecorationRegion enum.

See also regionAt() and paint().

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

This is an overloaded member function, provided for convenience.

int QDecoration::regionAt ( const QWidget * widget, const QPoint & point )   [virtual]

Returns the type of the first region of the specified top level widget containing the given point.

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

See also region().

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

Handles the event that the specified region in the given top level widget is activated by a single click (the region parameter is described using the DecorationRegion 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 also regionDoubleClicked() and region().

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

Handles the event that the specified region in the given top level widget is activated by a double click (the region parameter is described using the DecorationRegion 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 also regionClicked() and region().

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

Starts to move the given top level widget by making its Title region active and grabbing the mouse input.

See also startResize().

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

Starts to resize the given top level widget by making its BottomRight region active and grabbing the mouse input.

See also startMove().