Wt
4.10.3
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The abstract base class for a paint device. More...
#include <Wt/WPaintDevice.h>
Public Types | |
typedef PaintDeviceFeatureFlag | FeatureFlag |
Typedef for enum Wt::PaintDeviceFeatureFlag. | |
Protected Member Functions | |
virtual WPainter * | painter () const =0 |
Returns the painter that is currently painting on the device. | |
virtual void | setPainter (WPainter *painter)=0 |
Sets the painter. | |
The abstract base class for a paint device.
A WPaintDevice is a device on which may be painted using a WPainter. You should never paint directly on a paint device.
The device defines the size of the drawing area, using width() and height(). These dimensions must be defined in pixel units. In the future, additional information will be included to convert these pixel units to lengths (using DPI information).
You should reimplement this class if you wish to extend the Wt paint system to paint on other devices than the ones provided by the library.
Note: this interface is subject to changes to increase optimization possibilities for the painting using different devices.
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virtual |
Destructor.
Frees all resources associated with this device.
Finishes painting on the device.
This method is called when a WPainter stopped painting.
Implemented in Wt::WCanvasPaintDevice, Wt::WMeasurePaintDevice, Wt::WPdfImage, Wt::WRasterImage, Wt::WSvgImage, and Wt::WVmlImage.
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pure virtual |
Draws an arc.
The arc describes the segment of an ellipse enclosed by the rect. The segment starts at startAngle
, and spans an angle given by spanAngle
. These angles have as unit degree, and are measured counter-clockwise starting from the 3 o'clock position.
The arc must be stroked, filled, and transformed using the current painter settings.
Implemented in Wt::WCanvasPaintDevice, Wt::WMeasurePaintDevice, Wt::WPdfImage, Wt::WRasterImage, Wt::WSvgImage, and Wt::WVmlImage.
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pure virtual |
Draws an image.
Draws sourceRect from the image with URL imageUri
and original dimensions imgWidth and imgHeight
to the location, into the rectangle defined by rect
.
The image is transformed using the current painter settings.
Implemented in Wt::WCanvasPaintDevice, Wt::WMeasurePaintDevice, Wt::WPdfImage, Wt::WRasterImage, Wt::WSvgImage, and Wt::WVmlImage.
Draws a line.
The line must be stroked and transformed using the current painter settings.
Implemented in Wt::WCanvasPaintDevice, Wt::WMeasurePaintDevice, Wt::WPdfImage, Wt::WRasterImage, Wt::WSvgImage, and Wt::WVmlImage.
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pure virtual |
Draws a path.
The path must be stroked, filled, and transformed using the current painter settings.
Implemented in Wt::WCanvasPaintDevice, Wt::WMeasurePaintDevice, Wt::WPdfImage, Wt::WRasterImage, Wt::WSvgImage, and Wt::WVmlImage.
Draws a rectangle.
The rect must be stroked, filled, and transformed using the current painter settings.
Implemented in Wt::WPdfImage, Wt::WRasterImage, Wt::WCanvasPaintDevice, Wt::WMeasurePaintDevice, Wt::WSvgImage, and Wt::WVmlImage.
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pure virtual |
Draws text.
The text must be rendered, stroked and transformed using the current painter settings.
If clipPoint is not null, a check is performed whether the point is inside of the current clip area. If not, the text is not drawn.
Implemented in Wt::WCanvasPaintDevice, Wt::WMeasurePaintDevice, Wt::WPdfImage, Wt::WRasterImage, Wt::WSvgImage, and Wt::WVmlImage.
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pure virtual |
Returns font metrics.
This returns font metrics for the current font.
Throws a std::logic_error if the underlying device does not provide font metrics.
Implemented in Wt::WCanvasPaintDevice, Wt::WMeasurePaintDevice, Wt::WPdfImage, Wt::WRasterImage, Wt::WSvgImage, and Wt::WVmlImage.
Returns the device height.
The device height, in pixels, establishes the height of the device coordinate system.
Implemented in Wt::WCanvasPaintDevice, Wt::WMeasurePaintDevice, Wt::WPdfImage, Wt::WRasterImage, Wt::WSvgImage, and Wt::WVmlImage.
Initializes the device for painting.
This method is called when a WPainter starts painting.
Implemented in Wt::WCanvasPaintDevice, Wt::WMeasurePaintDevice, Wt::WPdfImage, Wt::WRasterImage, Wt::WSvgImage, and Wt::WVmlImage.
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pure virtual |
Measures rendered text size.
Returns the bounding rect of the given text when rendered using the current font.
If maxWidth
!= -1, then the text is truncated to fit in the width.
If wordWrap
= true
then text is truncated only at word boundaries. Note that in this case the whitespace at the truncated position is included in the text but not accounted for by the returned width (since usually you will not render the whitespace at the end of a line).
Throws a std::logic_error if the underlying device does not provide font metrics.
Implemented in Wt::WCanvasPaintDevice, Wt::WMeasurePaintDevice, Wt::WPdfImage, Wt::WRasterImage, Wt::WSvgImage, and Wt::WVmlImage.
Returns whether painting is active.
Implemented in Wt::WCanvasPaintDevice, Wt::WMeasurePaintDevice, Wt::WPdfImage, Wt::WRasterImage, Wt::WSvgImage, and Wt::WVmlImage.
Returns the painter that is currently painting on the device.
Implemented in Wt::WCanvasPaintDevice, Wt::WMeasurePaintDevice, Wt::WPdfImage, Wt::WRasterImage, Wt::WSvgImage, and Wt::WVmlImage.
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pure virtual |
Indicates changes in painter state.
The flags
argument is the logical OR of one or more change flags.
Implemented in Wt::WCanvasPaintDevice, Wt::WMeasurePaintDevice, Wt::WPdfImage, Wt::WRasterImage, Wt::WSvgImage, and Wt::WVmlImage.
Returns the device width.
The device width, in pixels, establishes the width of the device coordinate system.
Implemented in Wt::WCanvasPaintDevice, Wt::WMeasurePaintDevice, Wt::WPdfImage, Wt::WRasterImage, Wt::WSvgImage, and Wt::WVmlImage.