QCustomRasterPaintDevice Class Reference

The QCustomRasterPaintDevice class is provided to activate hardware accelerated paint engines in Qt for Embedded Linux. More...

#include <qpaintengine_raster_p.h>

Inheritance diagram for QCustomRasterPaintDevice:

Public Functions
virtual int	bytesPerLine () const
	Returns the number of bytes per line in the framebuffer. More...
int	devType () const
virtual QImage::Format	format () const
	Returns the format of the device's memory buffet. More...
virtual void *	memory () const
	Returns a pointer to the paint device's memory buffer, or 0 if no such buffer exists. More...
virtual int	metric (PaintDeviceMetric m) const
	Reimplemented Function More...
	QCustomRasterPaintDevice (QWidget *w)
	Constructs a custom raster based paint device for the given top-level widget. More...
virtual QSize	size () const
Public Functions inherited from QPaintDevice
int	colorCount () const
int	depth () const
virtual HDC	getDC () const
int	height () const
int	heightMM () const
int	logicalDpiX () const
int	logicalDpiY () const
QT_DEPRECATED int	numColors () const
virtual QPaintEngine *	paintEngine () const =0
bool	paintingActive () const
int	physicalDpiX () const
int	physicalDpiY () const
virtual void	releaseDC (HDC hdc) const
int	width () const
int	widthMM () const
virtual	~QPaintDevice ()

Properties
QWidget *	widget

Additional Inherited Members
Public Types inherited from QPaintDevice
enum	PaintDeviceMetric {   PdmWidth = 1, PdmHeight, PdmWidthMM, PdmHeightMM,   PdmNumColors, PdmDepth, PdmDpiX, PdmDpiY,   PdmPhysicalDpiX, PdmPhysicalDpiY }
Static Public Functions inherited from QPaintDevice
static QWSDisplay *	qwsDisplay ()
Protected Functions inherited from QPaintDevice
	QPaintDevice ()
Protected Variables inherited from QPaintDevice
ushort	painters
Related Functions inherited from QPaintDevice
const Q_GUI_EXPORT QX11Info *	qt_x11Info (const QPaintDevice *pd)
	Returns the QX11Info structure for the pd paint device. More...

Detailed Description

The QCustomRasterPaintDevice class is provided to activate hardware accelerated paint engines in Qt for Embedded Linux.

This function is under development and subject to change.

Since

4.2

Note that this class is only available in Qt for Embedded Linux.

In Qt for Embedded Linux, painting is a pure software implementation. But starting with Qt 4.2, it is possible to add an accelerated graphics driver to take advantage of available hardware resources.

Hardware acceleration is accomplished by creating a custom screen driver, accelerating the copying from memory to the screen, and implementing a custom paint engine accelerating the various painting operations. Then a custom paint device (derived from the QCustomRasterPaintDevice class) and a custom window surface (derived from QWSWindowSurface) must be implemented to make Qt for Embedded Linux aware of the accelerated driver.

See the Adding an Accelerated Graphics Driver to Qt for Embedded Linux documentation for details.

See also

QRasterPaintEngine, QPaintDevice

Definition at line 468 of file qpaintengine_raster_p.h.

Constructors and Destructors

QCustomRasterPaintDevice()

QCustomRasterPaintDevice::QCustomRasterPaintDevice ( QWidget *  w )

inline

Constructs a custom raster based paint device for the given top-level widget.

Definition at line 471 of file qpaintengine_raster_p.h.

: widget(w) {}

Functions

bytesPerLine()

int QCustomRasterPaintDevice::bytesPerLine ( ) const

virtual

Returns the number of bytes per line in the framebuffer.

Note that this number might be larger than the framebuffer width.

Reimplemented in QDirectFBPaintDevice.

Definition at line 3983 of file qpaintengine_raster.cpp.

Referenced by QRasterBuffer::prepare().

{
    return (width() * depth() + 7) / 8;
}

devType()

int QCustomRasterPaintDevice::devType ( ) const

inlinevirtual

Warning

This function is not part of the public interface.

Reimplemented from QPaintDevice.

Definition at line 473 of file qpaintengine_raster_p.h.

{ return QInternal::CustomRaster; }

format()

QImage::Format QCustomRasterPaintDevice::format ( ) const

inlinevirtual

Returns the format of the device's memory buffet.

The default format is QImage::Format_ARGB32_Premultiplied. The only other valid format is QImage::Format_RGB16.

Reimplemented in QDirectFBPaintDevice.

Definition at line 479 of file qpaintengine_raster_p.h.

Referenced by QRasterBuffer::prepare().

                                        {
        return QImage::Format_ARGB32_Premultiplied;
    }

memory()

void * QCustomRasterPaintDevice::memory ( ) const

inlinevirtual

Returns a pointer to the paint device's memory buffer, or 0 if no such buffer exists.

Reimplemented in QDirectFBPaintDevice.

Definition at line 477 of file qpaintengine_raster_p.h.

Referenced by QRasterBuffer::prepare().

{ return 0; }

metric()

int QCustomRasterPaintDevice::metric ( PaintDeviceMetric  m ) const

virtual

Reimplemented Function

Reimplemented from QPaintDevice.

Reimplemented in QDirectFBPixmapData, and QDirectFBPaintDevice.

Definition at line 3969 of file qpaintengine_raster.cpp.

{
    switch (m) {
    case PdmWidth:
        return widget->frameGeometry().width();
    case PdmHeight:
        return widget->frameGeometry().height();
    default:
        break;
    }

    return qt_paint_device_metric(widget, m);
}

size()

QSize QCustomRasterPaintDevice::size ( ) const

inlinevirtual

Warning

This function is not part of the public interface.

Reimplemented in QDirectFBPaintDevice.

Definition at line 485 of file qpaintengine_raster_p.h.

                               {
        return static_cast<QRasterPaintEngine*>(paintEngine())->size();
    }

Properties

widget

QWidget* QCustomRasterPaintDevice::widget

private

Definition at line 490 of file qpaintengine_raster_p.h.

---

The documentation for this class was generated from the following files:

• /src/gui/painting/qpaintengine_raster_p.h
• /src/gui/painting/qpaintengine_raster.cpp