Qt 4.8: QPaintEngineState Class Reference

Qt Reference Documentation

- Qt 4.8
- ALL VERSIONS

- A
- A
- A
- Print

# QPaintEngineState Class Reference

The QPaintEngineState class provides information about the active paint engine's current state. More...

     #include <QPaintEngineState>

Note: All functions in this class are reentrant.

This class was introduced in Qt 4.1.

- List of all members, including inherited members
- Obsolete members

## Public Functions

QBrush | backgroundBrush () const
Qt::BGMode | backgroundMode () const
QBrush | brush () const
bool | brushNeedsResolving () const
QPointF | brushOrigin () const
Qt::ClipOperation | clipOperation () const
QPainterPath | clipPath () const
QRegion | clipRegion () const
QPainter::CompositionMode | compositionMode () const
QFont | font () const
bool | isClipEnabled () const
qreal | opacity () const
QPainter * | painter () const
QPen | pen () const
bool | penNeedsResolving () const
QPainter::RenderHints | renderHints () const
QPaintEngine::DirtyFlags | state () const
QTransform | transform () const

## Detailed Description

The QPaintEngineState class provides information about the active paint engine's current state.

QPaintEngineState records which properties that have changed since the last time the paint engine was updated, as well as their current value.

Which properties that have changed can at any time be retrieved using the state() function. This function returns an instance of the QPaintEngine::DirtyFlags type which stores an OR combination of QPaintEngine::DirtyFlag values. The QPaintEngine::DirtyFlag enum defines whether a property has changed since the last update or not.

If a property is marked with a dirty flag, its current value can be retrieved using the corresponding get function:

Property Flag | Current Property Value
--- | ---
QPaintEngine::DirtyBackground | backgroundBrush()
QPaintEngine::DirtyBackgroundMode | backgroundMode()
QPaintEngine::DirtyBrush | brush()
QPaintEngine::DirtyBrushOrigin | brushOrigin()
QPaintEngine::DirtyClipRegion or QPaintEngine::DirtyClipPath | clipOperation()
QPaintEngine::DirtyClipPath | clipPath()
QPaintEngine::DirtyClipRegion | clipRegion()
QPaintEngine::DirtyCompositionMode | compositionMode()
QPaintEngine::DirtyFont | font()
QPaintEngine::DirtyTransform | transform()
QPaintEngine::DirtyClipEnabled | isClipEnabled()
QPaintEngine::DirtyPen | pen()
QPaintEngine::DirtyHints | renderHints()

The QPaintEngineState class also provide the painter() function which returns a pointer to the painter that is currently updating the paint engine.

An instance of this class, representing the current state of the active paint engine, is passed as argument to the QPaintEngine::updateState() function. The only situation in which you will have to use this class directly is when implementing your own paint engine.

See also QPaintEngine.

## Member Function Documentation

### QBrush QPaintEngineState::backgroundBrush () const

Returns the background brush in the current paint engine state.

This variable should only be used when the state() returns a combination which includes the QPaintEngine::DirtyBackground flag.

See also state() and QPaintEngine::updateState().

### Qt::BGMode QPaintEngineState::backgroundMode () const

Returns the background mode in the current paint engine state.

This variable should only be used when the state() returns a combination which includes the QPaintEngine::DirtyBackgroundMode flag.

See also state() and QPaintEngine::updateState().

### QBrush QPaintEngineState::brush () const

Returns the brush in the current paint engine state.

This variable should only be used when the state() returns a combination which includes the QPaintEngine::DirtyBrush flag.

See also state() and QPaintEngine::updateState().

### bool QPaintEngineState::brushNeedsResolving () const

Returns whether the coordinate of the fill have been specified as bounded by the current rendering operation and have to be resolved (about the currently rendered primitive).

This function was introduced in Qt 4.3.

### QPointF QPaintEngineState::brushOrigin () const

Returns the brush origin in the current paint engine state.

This variable should only be used when the state() returns a combination which includes the QPaintEngine::DirtyBrushOrigin flag.

See also state() and QPaintEngine::updateState().

### Qt::ClipOperation QPaintEngineState::clipOperation () const

Returns the clip operation in the current paint engine state.

This variable should only be used when the state() returns a combination which includes either the QPaintEngine::DirtyClipPath or the QPaintEngine::DirtyClipRegion flag.

See also state() and QPaintEngine::updateState().

### QPainterPath QPaintEngineState::clipPath () const

Returns the clip path in the current paint engine state.

This variable should only be used when the state() returns a combination which includes the QPaintEngine::DirtyClipPath flag.

See also state() and QPaintEngine::updateState().

### QRegion QPaintEngineState::clipRegion () const

Returns the clip region in the current paint engine state.

This variable should only be used when the state() returns a combination which includes the QPaintEngine::DirtyClipRegion flag.

See also state() and QPaintEngine::updateState().

### QPainter::CompositionMode QPaintEngineState::compositionMode () const

Returns the composition mode in the current paint engine state.

This variable should only be used when the state() returns a combination which includes the QPaintEngine::DirtyCompositionMode flag.

See also state() and QPaintEngine::updateState().

### QFont QPaintEngineState::font () const

Returns the font in the current paint engine state.

This variable should only be used when the state() returns a combination which includes the QPaintEngine::DirtyFont flag.

See also state() and QPaintEngine::updateState().

### bool QPaintEngineState::isClipEnabled () const

Returns whether clipping is enabled or not in the current paint engine state.

This variable should only be used when the state() returns a combination which includes the QPaintEngine::DirtyClipEnabled flag.

See also state() and QPaintEngine::updateState().

### qreal QPaintEngineState::opacity () const

Returns the opacity in the current paint engine state.

This function was introduced in Qt 4.2.

### QPainter * QPaintEngineState::painter () const

Returns a pointer to the painter currently updating the paint engine.

### QPen QPaintEngineState::pen () const

Returns the pen in the current paint engine state.

This variable should only be used when the state() returns a combination which includes the QPaintEngine::DirtyPen flag.

See also state() and QPaintEngine::updateState().

### bool QPaintEngineState::penNeedsResolving () const

Returns whether the coordinate of the stroke have been specified as bounded by the current rendering operation and have to be resolved (about the currently rendered primitive).

This function was introduced in Qt 4.3.

### QPainter::RenderHints QPaintEngineState::renderHints () const

Returns the render hints in the current paint engine state.

This variable should only be used when the state() returns a combination which includes the QPaintEngine::DirtyHints flag.

See also state() and QPaintEngine::updateState().

### QPaintEngine::DirtyFlags QPaintEngineState::state () const

Returns a combination of flags identifying the set of properties that need to be updated when updating the paint engine's state (i.e. during a call to the QPaintEngine::updateState() function).

See also QPaintEngine::updateState().

### QTransform QPaintEngineState::transform () const

Returns the matrix in the current paint engine state.

This variable should only be used when the state() returns a combination which includes the QPaintEngine::DirtyTransform flag.

This function was introduced in Qt 4.3.

See also state() and QPaintEngine::updateState().