Class GC


  • public class GC
    extends Resource
    Class GC is where all of the drawing capabilities that are supported by SWT are located. Instances are used to draw on a Control.
    Styles:
    LEFT_TO_RIGHT

    The SWT drawing coordinate system is the two-dimensional space with the origin (0,0) at the top left corner of the drawing area and with (x,y) values increasing to the right and downward respectively.

    Application code must explicitly invoke the GC.dispose() method to release the operating system resources managed by each instance when those instances are no longer required.

    Since:
    1.3
    See Also:
    PaintEvent
    • Constructor Summary

      Constructors 
      Constructor Description
      GC​(Drawable drawable)
      Constructs a new instance of this class which has been configured to draw on the specified drawable.
      GC​(Drawable drawable, int style)
      Constructs a new instance of this class which has been configured to draw on the specified drawable.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void drawArc​(int x, int y, int width, int height, int startAngle, int arcAngle)
      Draws the outline of a circular or elliptical arc within the specified rectangular area.
      void drawFocus​(int x, int y, int width, int height)
      Draws a rectangle, based on the specified arguments, which has the appearance of the platform's focus rectangle if the platform supports such a notion, and otherwise draws a simple rectangle in the receiver's foreground color.
      void drawImage​(Image image, int x, int y)
      Draws the given image in the receiver at the specified coordinates.
      void drawImage​(Image image, int srcX, int srcY, int srcWidth, int srcHeight, int destX, int destY, int destWidth, int destHeight)
      Copies a rectangular area from the source image into a (potentially different sized) rectangular area in the receiver.
      void drawLine​(int x1, int y1, int x2, int y2)
      Draws a line, using the foreground color, between the points (x1, y1) and (x2, y2).
      void drawOval​(int x, int y, int width, int height)
      Draws the outline of an oval, using the foreground color, within the specified rectangular area.
      void drawPath​(Path path)
      Draws the path described by the parameter.
      void drawPoint​(int x, int y)
      Draws a pixel, using the foreground color, at the specified point (x, y).
      void drawPolygon​(int[] pointArray)
      Draws the closed polygon which is defined by the specified array of integer coordinates, using the receiver's foreground color.
      void drawPolyline​(int[] pointArray)
      Draws the polyline which is defined by the specified array of integer coordinates, using the receiver's foreground color.
      void drawRectangle​(int x, int y, int width, int height)
      Draws the outline of the rectangle specified by the arguments, using the receiver's foreground color.
      void drawRectangle​(Rectangle rect)
      Draws the outline of the specified rectangle, using the receiver's foreground color.
      void drawRoundRectangle​(int x, int y, int width, int height, int arcWidth, int arcHeight)
      Draws the outline of the round-cornered rectangle specified by the arguments, using the receiver's foreground color.
      void drawString​(java.lang.String string, int x, int y)
      Draws the given string, using the receiver's current font and foreground color.
      void drawString​(java.lang.String string, int x, int y, boolean isTransparent)
      Draws the given string, using the receiver's current font and foreground color.
      void drawText​(java.lang.String string, int x, int y)
      Draws the given string, using the receiver's current font and foreground color.
      void drawText​(java.lang.String string, int x, int y, boolean isTransparent)
      Draws the given string, using the receiver's current font and foreground color.
      void drawText​(java.lang.String string, int x, int y, int flags)
      Draws the given string, using the receiver's current font and foreground color.
      void fillArc​(int x, int y, int width, int height, int startAngle, int arcAngle)
      Fills the interior of a circular or elliptical arc within the specified rectangular area, with the receiver's background color.
      void fillGradientRectangle​(int x, int y, int width, int height, boolean vertical)
      Fills the interior of the specified rectangle with a gradient sweeping from left to right or top to bottom progressing from the receiver's foreground color to its background color.
      void fillOval​(int x, int y, int width, int height)
      Fills the interior of an oval, within the specified rectangular area, with the receiver's background color.
      void fillPath​(Path path)
      Fills the path described by the parameter.
      void fillPolygon​(int[] pointArray)
      Fills the interior of the closed polygon which is defined by the specified array of integer coordinates, using the receiver's background color.
      void fillRectangle​(int x, int y, int width, int height)
      Fills the interior of the rectangle specified by the arguments, using the receiver's background color.
      void fillRectangle​(Rectangle rect)
      Fills the interior of the specified rectangle, using the receiver's background color.
      void fillRoundRectangle​(int x, int y, int width, int height, int arcWidth, int arcHeight)
      Fills the interior of the round-cornered rectangle specified by the arguments, using the receiver's background color.
      boolean getAdvanced()
      Returns true if receiver is using the operating system's advanced graphics subsystem.
      int getAlpha()
      Returns the receiver's alpha value.
      int getAntialias()
      Returns the receiver's anti-aliasing setting value, which will be one of SWT.DEFAULT, SWT.OFF or SWT.ON.
      Color getBackground()
      Returns the background color.
      int getCharWidth​(char ch)
      Returns the width of the specified character in the font selected into the receiver.
      Rectangle getClipping()
      Returns the bounding rectangle of the receiver's clipping region.
      Font getFont()
      Returns the font currently being used by the receiver to draw and measure text.
      FontMetrics getFontMetrics()
      Returns a FontMetrics which contains information about the font currently being used by the receiver to draw and measure text.
      Color getForeground()
      Returns the receiver's foreground color.
      LineAttributes getLineAttributes()
      Returns the receiver's line attributes.
      int getLineCap()
      Returns the receiver's line cap style, which will be one of the constants SWT.CAP_FLAT, SWT.CAP_ROUND, or SWT.CAP_SQUARE.
      int[] getLineDash()
      Returns the receiver's line dash style.
      int getLineJoin()
      Returns the receiver's line join style, which will be one of the constants SWT.JOIN_MITER, SWT.JOIN_ROUND, or SWT.JOIN_BEVEL.
      int getLineStyle()
      Returns the receiver's line style, which will be one of the constants SWT.LINE_SOLID, SWT.LINE_DASH, SWT.LINE_DOT, SWT.LINE_DASHDOT or SWT.LINE_DASHDOTDOT.
      int getLineWidth()
      Returns the width that will be used when drawing lines for all of the figure drawing operations (that is, drawLine, drawRectangle, drawPolyline, and so forth.
      int getStyle()
      Returns the receiver's style information.
      int getTextAntialias()
      Returns the receiver's text drawing anti-aliasing setting value, which will be one of SWT.DEFAULT, SWT.OFF or SWT.ON.
      void getTransform​(Transform transform)
      Sets the parameter to the transform that is currently being used by the receiver.
      void setAdvanced​(boolean advanced)
      Sets the receiver to always use the operating system's advanced graphics subsystem for all graphics operations if the argument is true.
      void setAlpha​(int alpha)
      Sets the receiver's alpha value which must be between 0 (transparent) and 255 (opaque).
      void setAntialias​(int antialias)
      Sets the receiver's anti-aliasing value to the parameter, which must be one of SWT.DEFAULT, SWT.OFF or SWT.ON.
      void setBackground​(Color color)
      Sets the background color.
      void setClipping​(int x, int y, int width, int height)
      Sets the area of the receiver which can be changed by drawing operations to the rectangular area specified by the arguments.
      void setClipping​(Path path)
      Sets the area of the receiver which can be changed by drawing operations to the path specified by the argument.
      void setClipping​(Rectangle rect)
      Sets the area of the receiver which can be changed by drawing operations to the rectangular area specified by the argument.
      void setFont​(Font font)
      Sets the font which will be used by the receiver to draw and measure text to the argument.
      void setForeground​(Color color)
      Sets the foreground color.
      void setLineAttributes​(LineAttributes attributes)
      Sets the receiver's line attributes.
      void setLineCap​(int lineCap)
      Sets the receiver's line cap style to the argument, which must be one of the constants SWT.CAP_FLAT, SWT.CAP_ROUND, or SWT.CAP_SQUARE.
      void setLineDash​(int[] dashes)
      Sets the receiver's line dash style to the argument.
      void setLineJoin​(int lineJoin)
      Sets the receiver's line join style to the argument, which must be one of the constants SWT.JOIN_MITER, SWT.JOIN_ROUND, or SWT.JOIN_BEVEL.
      void setLineStyle​(int lineStyle)
      Sets the receiver's line style to the argument, which must be one of the constants SWT.LINE_SOLID, SWT.LINE_DASH, SWT.LINE_DOT, SWT.LINE_DASHDOT or SWT.LINE_DASHDOTDOT.
      void setLineWidth​(int lineWidth)
      Sets the width that will be used when drawing lines for all of the figure drawing operations (that is, drawLine, drawRectangle, drawPolyline, and so forth.
      void setTextAntialias​(int antialias)
      Sets the receiver's text anti-aliasing value to the parameter, which must be one of SWT.DEFAULT, SWT.OFF or SWT.ON.
      void setTransform​(Transform transform)
      Sets the transform that is currently being used by the receiver.
      Point stringExtent​(java.lang.String string)
      Returns the extent of the given string.
      Point textExtent​(java.lang.String string)
      Returns the extent of the given string.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • GC

        public GC​(Drawable drawable)
        Constructs a new instance of this class which has been configured to draw on the specified drawable. Sets the foreground color, background color and font in the GC to match those in the drawable.

        You must dispose the graphics context when it is no longer required.

        Parameters:
        drawable - the drawable to draw on
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the drawable is null
        • ERROR_NULL_ARGUMENT - if there is no current device
        • ERROR_INVALID_ARGUMENT - if the drawable is an image that is not a bitmap or an icon - if the drawable is an image or printer that is already selected into another graphics context
        SWTError -
        • ERROR_NO_HANDLES if a handle could not be obtained for GC creation
        • ERROR_THREAD_INVALID_ACCESS if not called from the thread that created the drawable
      • GC

        public GC​(Drawable drawable,
                  int style)
        Constructs a new instance of this class which has been configured to draw on the specified drawable. Sets the foreground color, background color and font in the GC to match those in the drawable.

        You must dispose the graphics context when it is no longer required.

        Parameters:
        drawable - the drawable to draw on
        style - the style of GC to construct
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the drawable is null
        • ERROR_NULL_ARGUMENT - if there is no current device
        • ERROR_INVALID_ARGUMENT - if the drawable is an image that is not a bitmap or an icon - if the drawable is an image or printer that is already selected into another graphics context
        SWTError -
        • ERROR_NO_HANDLES if a handle could not be obtained for GC creation
        • ERROR_THREAD_INVALID_ACCESS if not called from the thread that created the drawable
    • Method Detail

      • setFont

        public void setFont​(Font font)
        Sets the font which will be used by the receiver to draw and measure text to the argument. If the argument is null, then a default font appropriate for the platform will be used instead.
        Parameters:
        font - the new font for the receiver, or null to indicate a default font
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_INVALID_ARGUMENT - if the font has been disposed
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • getFont

        public Font getFont()
        Returns the font currently being used by the receiver to draw and measure text.
        Returns:
        the receiver's font
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • getCharWidth

        public int getCharWidth​(char ch)
        Returns the width of the specified character in the font selected into the receiver.

        The width is defined as the space taken up by the actual character, not including the leading and tailing whitespace or overhang.

        Parameters:
        ch - the character to measure
        Returns:
        the width of the character
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • stringExtent

        public Point stringExtent​(java.lang.String string)
        Returns the extent of the given string. No tab expansion or carriage return processing will be performed.

        The extent of a string is the width and height of the rectangular area it would cover if drawn in a particular font (in this case, the current font in the receiver).

        Parameters:
        string - the string to measure
        Returns:
        a point containing the extent of the string
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the string is null
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • textExtent

        public Point textExtent​(java.lang.String string)
        Returns the extent of the given string. Tab expansion and carriage return processing are performed.

        The extent of a string is the width and height of the rectangular area it would cover if drawn in a particular font (in this case, the current font in the receiver).

        Parameters:
        string - the string to measure
        Returns:
        a point containing the extent of the string
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the string is null
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • getFontMetrics

        public FontMetrics getFontMetrics()
        Returns a FontMetrics which contains information about the font currently being used by the receiver to draw and measure text.
        Returns:
        font metrics for the receiver's font
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • setBackground

        public void setBackground​(Color color)
        Sets the background color. The background color is used for fill operations and as the background color when text is drawn.
        Parameters:
        color - the new background color for the receiver
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the color is null
        • ERROR_INVALID_ARGUMENT - if the color has been disposed
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • getBackground

        public Color getBackground()
        Returns the background color.
        Returns:
        the receiver's background color
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • setForeground

        public void setForeground​(Color color)
        Sets the foreground color. The foreground color is used for drawing operations including when text is drawn.
        Parameters:
        color - the new foreground color for the receiver
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the color is null
        • ERROR_INVALID_ARGUMENT - if the color has been disposed
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • getForeground

        public Color getForeground()
        Returns the receiver's foreground color.
        Returns:
        the color used for drawing foreground things
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • setClipping

        public void setClipping​(Rectangle rect)
        Sets the area of the receiver which can be changed by drawing operations to the rectangular area specified by the argument. Specifying null for the rectangle reverts the receiver's clipping area to its original value.
        Parameters:
        rect - the clipping rectangle or null
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        Since:
        3.0
      • setClipping

        public void setClipping​(int x,
                                int y,
                                int width,
                                int height)
        Sets the area of the receiver which can be changed by drawing operations to the rectangular area specified by the arguments.
        Parameters:
        x - the x coordinate of the clipping rectangle
        y - the y coordinate of the clipping rectangle
        width - the width of the clipping rectangle
        height - the height of the clipping rectangle
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        Since:
        3.0
      • setClipping

        public void setClipping​(Path path)
        Sets the area of the receiver which can be changed by drawing operations to the path specified by the argument.

        This operation requires the operating system's advanced graphics subsystem which may not be available on some platforms.

        Parameters:
        path - the clipping path.
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_INVALID_ARGUMENT - if the path has been disposed
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        • ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available
        Since:
        3.0
        See Also:
        Path, getAdvanced(), setAdvanced(boolean)
      • getClipping

        public Rectangle getClipping()
        Returns the bounding rectangle of the receiver's clipping region. If no clipping region is set, the return value will be a rectangle which covers the entire bounds of the object the receiver is drawing on.
        Returns:
        the bounding rectangle of the clipping region
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • setAlpha

        public void setAlpha​(int alpha)
        Sets the receiver's alpha value which must be between 0 (transparent) and 255 (opaque).

        This operation requires the operating system's advanced graphics subsystem which may not be available on some platforms.

        Parameters:
        alpha - the alpha value
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        • ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available
      • getAlpha

        public int getAlpha()
        Returns the receiver's alpha value. The alpha value is between 0 (transparent) and 255 (opaque).
        Returns:
        the alpha value
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • setLineWidth

        public void setLineWidth​(int lineWidth)
        Sets the width that will be used when drawing lines for all of the figure drawing operations (that is, drawLine, drawRectangle, drawPolyline, and so forth.
        Parameters:
        lineWidth - the width of a line
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • getLineWidth

        public int getLineWidth()
        Returns the width that will be used when drawing lines for all of the figure drawing operations (that is, drawLine, drawRectangle, drawPolyline, and so forth.
        Returns:
        the receiver's line width
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • setLineCap

        public void setLineCap​(int lineCap)
        Sets the receiver's line cap style to the argument, which must be one of the constants SWT.CAP_FLAT, SWT.CAP_ROUND, or SWT.CAP_SQUARE.
        Parameters:
        lineCap - the cap style to be used for drawing lines
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_INVALID_ARGUMENT - if the style is not valid
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • getLineCap

        public int getLineCap()
        Returns the receiver's line cap style, which will be one of the constants SWT.CAP_FLAT, SWT.CAP_ROUND, or SWT.CAP_SQUARE.
        Returns:
        the cap style used for drawing lines
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • setLineJoin

        public void setLineJoin​(int lineJoin)
        Sets the receiver's line join style to the argument, which must be one of the constants SWT.JOIN_MITER, SWT.JOIN_ROUND, or SWT.JOIN_BEVEL.
        Parameters:
        lineJoin - the join style to be used for drawing lines
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_INVALID_ARGUMENT - if the style is not valid
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • getLineJoin

        public int getLineJoin()
        Returns the receiver's line join style, which will be one of the constants SWT.JOIN_MITER, SWT.JOIN_ROUND, or SWT.JOIN_BEVEL.
        Returns:
        the join style used for drawing lines
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • setLineStyle

        public void setLineStyle​(int lineStyle)
        Sets the receiver's line style to the argument, which must be one of the constants SWT.LINE_SOLID, SWT.LINE_DASH, SWT.LINE_DOT, SWT.LINE_DASHDOT or SWT.LINE_DASHDOTDOT.
        Parameters:
        lineStyle - the style to be used for drawing lines
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_INVALID_ARGUMENT - if the style is not valid
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        Since:
        3.19
      • getLineStyle

        public int getLineStyle()
        Returns the receiver's line style, which will be one of the constants SWT.LINE_SOLID, SWT.LINE_DASH, SWT.LINE_DOT, SWT.LINE_DASHDOT or SWT.LINE_DASHDOTDOT.
        Returns:
        the style used for drawing lines
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        Since:
        3.19
      • setLineDash

        public void setLineDash​(int[] dashes)
        Sets the receiver's line dash style to the argument. The default value is null. If the argument is not null, the receiver's line style is set to SWT.LINE_CUSTOM, otherwise it is set to SWT.LINE_SOLID.
        Parameters:
        dashes - the dash style to be used for drawing lines
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_INVALID_ARGUMENT - if any of the values in the array is less than or equal 0
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        Since:
        3.19
      • getLineDash

        public int[] getLineDash()
        Returns the receiver's line dash style. The default value is null.
        Returns:
        the line dash style used for drawing lines
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        Since:
        3.19
      • setLineAttributes

        public void setLineAttributes​(LineAttributes attributes)
        Sets the receiver's line attributes.

        This operation requires the operating system's advanced graphics subsystem which may not be available on some platforms.

        Parameters:
        attributes - the line attributes
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the attributes is null
        • ERROR_INVALID_ARGUMENT - if any of the line attributes is not valid
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        • ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available
        See Also:
        LineAttributes
      • getLineAttributes

        public LineAttributes getLineAttributes()
        Returns the receiver's line attributes.
        Returns:
        the line attributes used for drawing lines
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • setAdvanced

        public void setAdvanced​(boolean advanced)
        Sets the receiver to always use the operating system's advanced graphics subsystem for all graphics operations if the argument is true. If the argument is false, the advanced graphics subsystem is no longer used, advanced graphics state is cleared and the normal graphics subsystem is used from now on.

        Normally, the advanced graphics subsystem is invoked automatically when any one of the alpha, antialias, patterns, interpolation, paths, clipping or transformation operations in the receiver is requested. When the receiver is switched into advanced mode, the advanced graphics subsystem performs both advanced and normal graphics operations. Because the two subsystems are different, their output may differ. Switching to advanced graphics before any graphics operations are performed ensures that the output is consistent.

        Advanced graphics may not be installed for the operating system. In this case, this operation does nothing. Some operating system have only one graphics subsystem, so switching from normal to advanced graphics does nothing. However, switching from advanced to normal graphics will always clear the advanced graphics state, even for operating systems that have only one graphics subsystem.

        Parameters:
        advanced - the new advanced graphics state
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        Since:
        1.4
        See Also:
        setAlpha(int), setAntialias(int), setClipping(Path), setLineAttributes(org.eclipse.swt.graphics.LineAttributes), setTextAntialias(int), setTransform(org.eclipse.swt.graphics.Transform), getAdvanced()
      • setAntialias

        public void setAntialias​(int antialias)
        Sets the receiver's anti-aliasing value to the parameter, which must be one of SWT.DEFAULT, SWT.OFF or SWT.ON. Note that this controls anti-aliasing for all non-text drawing operations.

        This operation requires the operating system's advanced graphics subsystem which may not be available on some platforms.

        Parameters:
        antialias - the anti-aliasing setting
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_INVALID_ARGUMENT - if the parameter is not one of SWT.DEFAULT, SWT.OFF or SWT.ON
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        • ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available
        Since:
        1.5
        See Also:
        getAdvanced(), setAdvanced(boolean), setTextAntialias(int)
      • getAntialias

        public int getAntialias()
        Returns the receiver's anti-aliasing setting value, which will be one of SWT.DEFAULT, SWT.OFF or SWT.ON. Note that this controls anti-aliasing for all non-text drawing operations.
        Returns:
        the anti-aliasing setting
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        Since:
        1.5
        See Also:
        getTextAntialias()
      • setTextAntialias

        public void setTextAntialias​(int antialias)
        Sets the receiver's text anti-aliasing value to the parameter, which must be one of SWT.DEFAULT, SWT.OFF or SWT.ON. Note that this controls anti-aliasing only for all text drawing operations.

        This operation requires the operating system's advanced graphics subsystem which may not be available on some platforms.

        Parameters:
        antialias - the anti-aliasing setting
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_INVALID_ARGUMENT - if the parameter is not one of SWT.DEFAULT, SWT.OFF or SWT.ON
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        • ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available
        Since:
        1.5
        See Also:
        getAdvanced(), setAdvanced(boolean), setAntialias(int)
      • getTextAntialias

        public int getTextAntialias()
        Returns the receiver's text drawing anti-aliasing setting value, which will be one of SWT.DEFAULT, SWT.OFF or SWT.ON. Note that this controls anti-aliasing only for text drawing operations.
        Returns:
        the anti-aliasing setting
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        Since:
        1.5
        See Also:
        getAntialias()
      • getAdvanced

        public boolean getAdvanced()
        Returns true if receiver is using the operating system's advanced graphics subsystem. Otherwise, false is returned to indicate that normal graphics are in use.

        Advanced graphics may not be installed for the operating system. In this case, false is always returned. Some operating system have only one graphics subsystem. If this subsystem supports advanced graphics, then true is always returned. If any graphics operation such as alpha, antialias, patterns, interpolation, paths, clipping or transformation has caused the receiver to switch from regular to advanced graphics mode, true is returned. If the receiver has been explicitly switched to advanced mode and this mode is supported, true is returned.

        Returns:
        the advanced value
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        Since:
        1.4
        See Also:
        setAdvanced(boolean)
      • setTransform

        public void setTransform​(Transform transform)
        Sets the transform that is currently being used by the receiver. If the argument is null, the current transform is set to the identity transform.

        This operation requires the operating system's advanced graphics subsystem which may not be available on some platforms.

        Parameters:
        transform - the transform to set
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_INVALID_ARGUMENT - if the parameter has been disposed
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        • ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available
        Since:
        3.1
        See Also:
        Transform, getAdvanced(), setAdvanced(boolean)
      • getTransform

        public void getTransform​(Transform transform)
        Sets the parameter to the transform that is currently being used by the receiver.
        Parameters:
        transform - the destination to copy the transform into
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the parameter is null
        • ERROR_INVALID_ARGUMENT - if the parameter has been disposed
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        Since:
        3.1
        See Also:
        Transform
      • drawLine

        public void drawLine​(int x1,
                             int y1,
                             int x2,
                             int y2)
        Draws a line, using the foreground color, between the points (x1, y1) and (x2, y2).
        Parameters:
        x1 - the first point's x coordinate
        y1 - the first point's y coordinate
        x2 - the second point's x coordinate
        y2 - the second point's y coordinate
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • drawRectangle

        public void drawRectangle​(Rectangle rect)
        Draws the outline of the specified rectangle, using the receiver's foreground color. The left and right edges of the rectangle are at rect.x and rect.x + rect.width. The top and bottom edges are at rect.y and rect.y + rect.height.
        Parameters:
        rect - the rectangle to draw
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the rectangle is null
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • drawRectangle

        public void drawRectangle​(int x,
                                  int y,
                                  int width,
                                  int height)
        Draws the outline of the rectangle specified by the arguments, using the receiver's foreground color. The left and right edges of the rectangle are at x and x + width. The top and bottom edges are at y and y + height.
        Parameters:
        x - the x coordinate of the rectangle to be drawn
        y - the y coordinate of the rectangle to be drawn
        width - the width of the rectangle to be drawn
        height - the height of the rectangle to be drawn
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • drawFocus

        public void drawFocus​(int x,
                              int y,
                              int width,
                              int height)
        Draws a rectangle, based on the specified arguments, which has the appearance of the platform's focus rectangle if the platform supports such a notion, and otherwise draws a simple rectangle in the receiver's foreground color.
        Parameters:
        x - the x coordinate of the rectangle
        y - the y coordinate of the rectangle
        width - the width of the rectangle
        height - the height of the rectangle
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        See Also:
        drawRectangle(int, int, int, int)
      • fillRectangle

        public void fillRectangle​(Rectangle rect)
        Fills the interior of the specified rectangle, using the receiver's background color.
        Parameters:
        rect - the rectangle to be filled
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the rectangle is null
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        See Also:
        drawRectangle(int, int, int, int)
      • fillRectangle

        public void fillRectangle​(int x,
                                  int y,
                                  int width,
                                  int height)
        Fills the interior of the rectangle specified by the arguments, using the receiver's background color.
        Parameters:
        x - the x coordinate of the rectangle to be filled
        y - the y coordinate of the rectangle to be filled
        width - the width of the rectangle to be filled
        height - the height of the rectangle to be filled
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        See Also:
        drawRectangle(int, int, int, int)
      • fillGradientRectangle

        public void fillGradientRectangle​(int x,
                                          int y,
                                          int width,
                                          int height,
                                          boolean vertical)
        Fills the interior of the specified rectangle with a gradient sweeping from left to right or top to bottom progressing from the receiver's foreground color to its background color.
        Parameters:
        x - the x coordinate of the rectangle to be filled
        y - the y coordinate of the rectangle to be filled
        width - the width of the rectangle to be filled, may be negative (inverts direction of gradient if horizontal)
        height - the height of the rectangle to be filled, may be negative (inverts direction of gradient if vertical)
        vertical - if true sweeps from top to bottom, else sweeps from left to right
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        See Also:
        drawRectangle(int, int, int, int)
      • drawRoundRectangle

        public void drawRoundRectangle​(int x,
                                       int y,
                                       int width,
                                       int height,
                                       int arcWidth,
                                       int arcHeight)
        Draws the outline of the round-cornered rectangle specified by the arguments, using the receiver's foreground color. The left and right edges of the rectangle are at x and x + width. The top and bottom edges are at y and y + height. The roundness of the corners is specified by the arcWidth and arcHeight arguments, which are respectively the width and height of the ellipse used to draw the corners.
        Parameters:
        x - the x coordinate of the rectangle to be drawn
        y - the y coordinate of the rectangle to be drawn
        width - the width of the rectangle to be drawn
        height - the height of the rectangle to be drawn
        arcWidth - the width of the arc
        arcHeight - the height of the arc
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • fillRoundRectangle

        public void fillRoundRectangle​(int x,
                                       int y,
                                       int width,
                                       int height,
                                       int arcWidth,
                                       int arcHeight)
        Fills the interior of the round-cornered rectangle specified by the arguments, using the receiver's background color.
        Parameters:
        x - the x coordinate of the rectangle to be filled
        y - the y coordinate of the rectangle to be filled
        width - the width of the rectangle to be filled
        height - the height of the rectangle to be filled
        arcWidth - the width of the arc
        arcHeight - the height of the arc
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        See Also:
        drawRoundRectangle(int, int, int, int, int, int)
      • drawOval

        public void drawOval​(int x,
                             int y,
                             int width,
                             int height)
        Draws the outline of an oval, using the foreground color, within the specified rectangular area.

        The result is a circle or ellipse that fits within the rectangle specified by the x, y, width, and height arguments.

        The oval covers an area that is width + 1 pixels wide and height + 1 pixels tall.

        Parameters:
        x - the x coordinate of the upper left corner of the oval to be drawn
        y - the y coordinate of the upper left corner of the oval to be drawn
        width - the width of the oval to be drawn
        height - the height of the oval to be drawn
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • fillOval

        public void fillOval​(int x,
                             int y,
                             int width,
                             int height)
        Fills the interior of an oval, within the specified rectangular area, with the receiver's background color.
        Parameters:
        x - the x coordinate of the upper left corner of the oval to be filled
        y - the y coordinate of the upper left corner of the oval to be filled
        width - the width of the oval to be filled
        height - the height of the oval to be filled
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        See Also:
        drawOval(int, int, int, int)
      • drawArc

        public void drawArc​(int x,
                            int y,
                            int width,
                            int height,
                            int startAngle,
                            int arcAngle)
        Draws the outline of a circular or elliptical arc within the specified rectangular area.

        The resulting arc begins at startAngle and extends for arcAngle degrees, using the current color. Angles are interpreted such that 0 degrees is at the 3 o'clock position. A positive value indicates a counter-clockwise rotation while a negative value indicates a clockwise rotation.

        The center of the arc is the center of the rectangle whose origin is (x, y) and whose size is specified by the width and height arguments.

        The resulting arc covers an area width + 1 pixels wide by height + 1 pixels tall.

        Parameters:
        x - the x coordinate of the upper-left corner of the arc to be drawn
        y - the y coordinate of the upper-left corner of the arc to be drawn
        width - the width of the arc to be drawn
        height - the height of the arc to be drawn
        startAngle - the beginning angle
        arcAngle - the angular extent of the arc, relative to the start angle
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • fillArc

        public void fillArc​(int x,
                            int y,
                            int width,
                            int height,
                            int startAngle,
                            int arcAngle)
        Fills the interior of a circular or elliptical arc within the specified rectangular area, with the receiver's background color.

        The resulting arc begins at startAngle and extends for arcAngle degrees, using the current color. Angles are interpreted such that 0 degrees is at the 3 o'clock position. A positive value indicates a counter-clockwise rotation while a negative value indicates a clockwise rotation.

        The center of the arc is the center of the rectangle whose origin is (x, y) and whose size is specified by the width and height arguments.

        The resulting arc covers an area width + 1 pixels wide by height + 1 pixels tall.

        Parameters:
        x - the x coordinate of the upper-left corner of the arc to be filled
        y - the y coordinate of the upper-left corner of the arc to be filled
        width - the width of the arc to be filled
        height - the height of the arc to be filled
        startAngle - the beginning angle
        arcAngle - the angular extent of the arc, relative to the start angle
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        See Also:
        drawArc(int, int, int, int, int, int)
      • drawPolygon

        public void drawPolygon​(int[] pointArray)
        Draws the closed polygon which is defined by the specified array of integer coordinates, using the receiver's foreground color. The array contains alternating x and y values which are considered to represent points which are the vertices of the polygon. Lines are drawn between each consecutive pair, and between the first pair and last pair in the array.
        Parameters:
        pointArray - an array of alternating x and y values which are the vertices of the polygon
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT if pointArray is null
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • fillPolygon

        public void fillPolygon​(int[] pointArray)
        Fills the interior of the closed polygon which is defined by the specified array of integer coordinates, using the receiver's background color. The array contains alternating x and y values which are considered to represent points which are the vertices of the polygon. Lines are drawn between each consecutive pair, and between the first pair and last pair in the array.
        Parameters:
        pointArray - an array of alternating x and y values which are the vertices of the polygon
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT if pointArray is null
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        See Also:
        drawPolygon(int[])
      • drawPolyline

        public void drawPolyline​(int[] pointArray)
        Draws the polyline which is defined by the specified array of integer coordinates, using the receiver's foreground color. The array contains alternating x and y values which are considered to represent points which are the corners of the polyline. Lines are drawn between each consecutive pair, but not between the first pair and last pair in the array.
        Parameters:
        pointArray - an array of alternating x and y values which are the corners of the polyline
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the point array is null
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • drawPoint

        public void drawPoint​(int x,
                              int y)
        Draws a pixel, using the foreground color, at the specified point (x, y).

        Note that the receiver's line attributes do not affect this operation.

        Parameters:
        x - the point's x coordinate
        y - the point's y coordinate
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • drawImage

        public void drawImage​(Image image,
                              int x,
                              int y)
        Draws the given image in the receiver at the specified coordinates.
        Parameters:
        image - the image to draw
        x - the x coordinate of where to draw
        y - the y coordinate of where to draw
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the image is null
        • ERROR_INVALID_ARGUMENT - if the image has been disposed
        • ERROR_INVALID_ARGUMENT - if the given coordinates are outside the bounds of the image
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        SWTError -
        • ERROR_NO_HANDLES - if no handles are available to perform the operation
      • drawImage

        public void drawImage​(Image image,
                              int srcX,
                              int srcY,
                              int srcWidth,
                              int srcHeight,
                              int destX,
                              int destY,
                              int destWidth,
                              int destHeight)
        Copies a rectangular area from the source image into a (potentially different sized) rectangular area in the receiver. If the source and destination areas are of differing sizes, then the source area will be stretched or shrunk to fit the destination area as it is copied. The copy fails if any part of the source rectangle lies outside the bounds of the source image, or if any of the width or height arguments are negative.
        Parameters:
        image - the source image
        srcX - the x coordinate in the source image to copy from
        srcY - the y coordinate in the source image to copy from
        srcWidth - the width in pixels to copy from the source
        srcHeight - the height in pixels to copy from the source
        destX - the x coordinate in the destination to copy to
        destY - the y coordinate in the destination to copy to
        destWidth - the width in pixels of the destination rectangle
        destHeight - the height in pixels of the destination rectangle
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the image is null
        • ERROR_INVALID_ARGUMENT - if the image has been disposed
        • ERROR_INVALID_ARGUMENT - if any of the width or height arguments are negative.
        • ERROR_INVALID_ARGUMENT - if the source rectangle is not contained within the bounds of the source image
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        SWTError -
        • ERROR_NO_HANDLES - if no handles are available to perform the operation
      • drawString

        public void drawString​(java.lang.String string,
                               int x,
                               int y)
        Draws the given string, using the receiver's current font and foreground color. No tab expansion or carriage return processing will be performed. The background of the rectangular area where the string is being drawn will be filled with the receiver's background color.
        Parameters:
        string - the string to be drawn
        x - the x coordinate of the top left corner of the rectangular area where the string is to be drawn
        y - the y coordinate of the top left corner of the rectangular area where the string is to be drawn
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the string is null
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • drawString

        public void drawString​(java.lang.String string,
                               int x,
                               int y,
                               boolean isTransparent)
        Draws the given string, using the receiver's current font and foreground color. No tab expansion or carriage return processing will be performed. If isTransparent is true, then the background of the rectangular area where the string is being drawn will not be modified, otherwise it will be filled with the receiver's background color.
        Parameters:
        string - the string to be drawn
        x - the x coordinate of the top left corner of the rectangular area where the string is to be drawn
        y - the y coordinate of the top left corner of the rectangular area where the string is to be drawn
        isTransparent - if true the background will be transparent, otherwise it will be opaque
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the string is null
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • drawText

        public void drawText​(java.lang.String string,
                             int x,
                             int y)
        Draws the given string, using the receiver's current font and foreground color. Tab expansion and carriage return processing are performed. The background of the rectangular area where the text is being drawn will be filled with the receiver's background color.
        Parameters:
        string - the string to be drawn
        x - the x coordinate of the top left corner of the rectangular area where the text is to be drawn
        y - the y coordinate of the top left corner of the rectangular area where the text is to be drawn
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the string is null
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • drawText

        public void drawText​(java.lang.String string,
                             int x,
                             int y,
                             boolean isTransparent)
        Draws the given string, using the receiver's current font and foreground color. Tab expansion and carriage return processing are performed. If isTransparent is true, then the background of the rectangular area where the text is being drawn will not be modified, otherwise it will be filled with the receiver's background color.
        Parameters:
        string - the string to be drawn
        x - the x coordinate of the top left corner of the rectangular area where the text is to be drawn
        y - the y coordinate of the top left corner of the rectangular area where the text is to be drawn
        isTransparent - if true the background will be transparent, otherwise it will be opaque
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the string is null
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • drawText

        public void drawText​(java.lang.String string,
                             int x,
                             int y,
                             int flags)
        Draws the given string, using the receiver's current font and foreground color. Tab expansion, line delimiter and mnemonic processing are performed according to the specified flags. If flags includes DRAW_TRANSPARENT, then the background of the rectangular area where the text is being drawn will not be modified, otherwise it will be filled with the receiver's background color.

        The parameter flags may be a combination of:

        DRAW_DELIMITER
        draw multiple lines
        DRAW_TAB
        expand tabs
        DRAW_MNEMONIC
        underline the mnemonic character
        DRAW_TRANSPARENT
        transparent background

        Parameters:
        string - the string to be drawn
        x - the x coordinate of the top left corner of the rectangular area where the text is to be drawn
        y - the y coordinate of the top left corner of the rectangular area where the text is to be drawn
        flags - the flags specifying how to process the text
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the string is null
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • drawPath

        public void drawPath​(Path path)
        Draws the path described by the parameter.

        This operation requires the operating system's advanced graphics subsystem which may not be available on some platforms.

        Parameters:
        path - the path to draw
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the parameter is null
        • ERROR_INVALID_ARGUMENT - if the parameter has been disposed
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        • ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available
        Since:
        2.1
        See Also:
        Path
      • fillPath

        public void fillPath​(Path path)
        Fills the path described by the parameter.

        This operation requires the operating system's advanced graphics subsystem which may not be available on some platforms.

        Parameters:
        path - the path to fill
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the parameter is null
        • ERROR_INVALID_ARGUMENT - if the parameter has been disposed
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
        • ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available
        Since:
        2.1
        See Also:
        Path
      • getStyle

        public int getStyle()
        Returns the receiver's style information.

        Note that the value which is returned by this method may not match the value which was provided to the constructor when the receiver was created. This can occur when the underlying operating system does not support a particular combination of requested styles.

        Returns:
        the style bits
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed