Package org.eclipse.swt.graphics

Class GC

java.lang.Object
org.eclipse.swt.graphics.Resource
org.eclipse.swt.graphics.GC
public final 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 either an Image, a Control, or directly on a Display.
Styles:
LEFT_TO_RIGHT, RIGHT_TO_LEFT

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.

The result of drawing on an image that was created with an indexed palette using a color that is not in the palette is platform specific. Some platforms will match to the nearest color while other will draw the color itself. This happens because the allocated image might use a direct palette on platforms that do not support indexed palette.

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. This is particularly important on Windows95 and Windows98 where the operating system has a limited number of device contexts available.

Note: Only one of LEFT_TO_RIGHT and RIGHT_TO_LEFT may be specified.

See Also:

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    long
    handle
    the handle to the OS device context (Warning: This field is platform dependent)

  • 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

    Modifier and Type
    Method
    Description
    void
    copyArea(int srcX, int srcY, int width, int height, int destX, int destY)
    Copies a rectangular area of the receiver at the source position onto the receiver at the destination position.
    void
    copyArea(int srcX, int srcY, int width, int height, int destX, int destY, boolean paint)
    Copies a rectangular area of the receiver at the source position onto the receiver at the destination position.
    void
    copyArea(Image image, int x, int y)
    Copies a rectangular area of the receiver at the specified position into the image, which must be of type SWT.BITMAP.
    void
    dispose()
    Disposes of the operating system resources associated with this resource.
    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 an SWT logical point, 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(String string, int x, int y)
    Draws the given string, using the receiver's current font and foreground color.
    void
    drawString(String string, int x, int y, boolean isTransparent)
    Draws the given string, using the receiver's current font and foreground color.
    void
    drawText(String string, int x, int y)
    Draws the given string, using the receiver's current font and foreground color.
    void
    drawText(String string, int x, int y, boolean isTransparent)
    Draws the given string, using the receiver's current font and foreground color.
    void
    drawText(String string, int x, int y, int flags)
    Draws the given string, using the receiver's current font and foreground color.
    boolean
    equals(Object object)
    Compares the argument to the receiver, and returns true if they represent the same object using a class specific comparison.
    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
    getAdvanceWidth(char ch)
    Returns the advance width of the specified character in the font which is currently selected into the receiver.
    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.
    Pattern
    getBackgroundPattern()
    Returns the background pattern.
    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.
    void
    getClipping(Region region)
    Sets the region managed by the argument to the current clipping region of the receiver.
    int
    getFillRule()
    Returns the receiver's fill rule, which will be one of SWT.FILL_EVEN_ODD or SWT.FILL_WINDING.
    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.
    Pattern
    getForegroundPattern()
    Returns the foreground pattern.
    GCData
    getGCData()
    Returns the GCData.
    int
    getInterpolation()
    Returns the receiver's interpolation setting, which will be one of SWT.DEFAULT, SWT.NONE, SWT.LOW or SWT.HIGH.
    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.
    boolean
    getXORMode()
    Returns true if this GC is drawing in the mode where the resulting color in the destination is the exclusive or of the color values in the source and the destination, and false if it is drawing in the mode where the destination color is being replaced with the source color value.
    int
    hashCode()
    Returns an integer hash code for the receiver.
    boolean
    isClipped()
    Returns true if the receiver has a clipping region set into it, and false otherwise.
    boolean
    isDisposed()
    Returns true if the GC has been disposed, and false otherwise.
    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
    setBackgroundPattern(Pattern pattern)
    Sets the background pattern.
    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
    setClipping(Region region)
    Sets the area of the receiver which can be changed by drawing operations to the region specified by the argument.
    void
    setFillRule(int rule)
    Sets the receiver's fill rule to the parameter, which must be one of SWT.FILL_EVEN_ODD or SWT.FILL_WINDING.
    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
    setForegroundPattern(Pattern pattern)
    Sets the foreground pattern.
    void
    setInterpolation(int interpolation)
    Sets the receiver's interpolation setting to the parameter, which must be one of SWT.DEFAULT, SWT.NONE, SWT.LOW or SWT.HIGH.
    void
    setLineAttributes(LineAttributes attributes)
    Sets the receiver's line attributes.
    void
    setLineCap(int cap)
    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 join)
    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.
    void
    setXORMode(boolean xor)
    If the argument is true, puts the receiver in a drawing mode where the resulting color in the destination is the exclusive or of the color values in the source and the destination, and if the argument is false, puts the receiver in a drawing mode where the destination color is replaced with the source color value.
    Point
    stringExtent(String string)
    Returns the extent of the given string.
    Point
    textExtent(String string)
    Returns the extent of the given string.
    Point
    textExtent(String string, int flags)
    Returns the extent of the given string.
    String
    toString()
    Returns a string containing a concise, human-readable description of the receiver.
    static GC
    win32_new(long hDC, GCData data)
    Invokes platform specific functionality to wrap a graphics context.
    static GC
    win32_new(Drawable drawable, GCData data)
    Invokes platform specific functionality to allocate a new graphics context.

    Methods inherited from class org.eclipse.swt.graphics.Resource

    getDevice, setNonDisposeHandler

    Methods inherited from class java.lang.Object

    clone, finalize, getClass, notify, notifyAll, wait, wait, wait

  • Field Details

    • handle

      public long handle
      the handle to the OS device context (Warning: This field is platform dependent)

      IMPORTANT: This field is not part of the SWT public API. It is marked public only so that it can be shared within the packages provided by SWT. It is not available on all platforms and should never be accessed from application code.

      Restriction:
      This field is not intended to be referenced by clients.

  • Constructor Details

    • 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:
      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
      See Also:

    • 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:
      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
      Since:
      2.1.2
      See Also:

  • Method Details

    • copyArea

      public void copyArea(Image image, int x, int y)
      Copies a rectangular area of the receiver at the specified position into the image, which must be of type SWT.BITMAP.
      Parameters:
      image - the image to copy into
      x - the x coordinate in the receiver of the area to be copied
      y - the y coordinate in the receiver of the area to be copied
      Throws:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the image is null
      • ERROR_INVALID_ARGUMENT - if the image is not a bitmap or has been disposed
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

    • copyArea

      public void copyArea(int srcX, int srcY, int width, int height, int destX, int destY)
      Copies a rectangular area of the receiver at the source position onto the receiver at the destination position.
      Parameters:
      srcX - the x coordinate in the receiver of the area to be copied
      srcY - the y coordinate in the receiver of the area to be copied
      width - the width of the area to copy
      height - the height of the area to copy
      destX - the x coordinate in the receiver of the area to copy to
      destY - the y coordinate in the receiver of the area to copy to
      Throws:
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

    • copyArea

      public void copyArea(int srcX, int srcY, int width, int height, int destX, int destY, boolean paint)
      Copies a rectangular area of the receiver at the source position onto the receiver at the destination position.
      Parameters:
      srcX - the x coordinate in the receiver of the area to be copied
      srcY - the y coordinate in the receiver of the area to be copied
      width - the width of the area to copy
      height - the height of the area to copy
      destX - the x coordinate in the receiver of the area to copy to
      destY - the y coordinate in the receiver of the area to copy to
      paint - if true paint events will be generated for old and obscured areas
      Throws:
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      Since:
      3.1

    • 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 points wide by height + 1 points 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

    • 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:

    • 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:
      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 points to copy from the source
      srcHeight - the height in points 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 points of the destination rectangle
      destHeight - the height in points of the destination rectangle
      Throws:
      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

    • 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

    • 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 points wide and height + 1 points 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

    • 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:
      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:
      3.1
      See Also:

    • drawPoint

      public void drawPoint(int x, int y)
      Draws an SWT logical point, 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
      Since:
      3.0

    • 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:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT if pointArray is null
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

    • 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:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the point array 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

    • 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:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the rectangle is null
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

    • 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

    • drawString

      public void drawString(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.

      On Windows, drawString(java.lang.String, int, int) and drawText(java.lang.String, int, int) are slightly different, see drawString(String, int, int, boolean) for explanation.
      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:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the string is null
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

    • drawString

      public void drawString(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.

      On Windows, drawString(java.lang.String, int, int) and drawText(java.lang.String, int, int) are slightly different:
      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:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the string is null
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

    • drawText

      public void drawText(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.

      On Windows, drawString(java.lang.String, int, int) and drawText(java.lang.String, int, int) are slightly different, see drawString(String, int, int, boolean) for explanation.
      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:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the string is null
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

    • drawText

      public void drawText(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.

      On Windows, drawString(java.lang.String, int, int) and drawText(java.lang.String, int, int) are slightly different, see drawString(String, int, int, boolean) for explanation.
      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:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the string is null
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

    • drawText

      public void drawText(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.

      On Windows, drawString(java.lang.String, int, int) and drawText(java.lang.String, int, int) are slightly different, see drawString(String, int, int, boolean) for explanation.

      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:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the string is null
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

    • equals

      public boolean equals(Object object)
      Compares the argument to the receiver, and returns true if they represent the same object using a class specific comparison.
      Overrides:
      equals in class Object
      Parameters:
      object - the object to compare with this object
      Returns:
      true if the object is the same as this object and false otherwise
      See Also:

    • 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 points wide by height + 1 points 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:

    • 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:

    • 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:

    • 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:
      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:
      3.1
      See Also:

    • 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:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT if pointArray is null
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      See Also:

    • 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:

    • 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:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the rectangle is null
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      See Also:

    • 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:

    • getAdvanceWidth

      public int getAdvanceWidth(char ch)
      Returns the advance width of the specified character in the font which is currently selected into the receiver.

      The advance width is defined as the horizontal distance the cursor should move after printing the character in the selected font.

      Parameters:
      ch - the character to measure
      Returns:
      the distance in the x direction to move past the character before painting the next
      Throws:
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

    • 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:
      3.1
      See Also:

    • 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
      Since:
      3.1

    • 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:
      3.1
      See Also:

    • 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

    • getBackgroundPattern

      public Pattern getBackgroundPattern()
      Returns the background pattern. The default value is null.
      Returns:
      the receiver's background pattern
      Throws:
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      Since:
      3.1
      See Also:

    • 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

    • 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

    • getClipping

      public void getClipping(Region region)
      Sets the region managed by the argument to the current clipping region of the receiver.
      Parameters:
      region - the region to fill with the clipping region
      Throws:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the region is null
      • ERROR_INVALID_ARGUMENT - if the region is disposed
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

    • getFillRule

      public int getFillRule()
      Returns the receiver's fill rule, which will be one of SWT.FILL_EVEN_ODD or SWT.FILL_WINDING.
      Returns:
      the receiver's fill rule
      Throws:
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      Since:
      3.1

    • 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

    • 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

    • 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

    • getForegroundPattern

      public Pattern getForegroundPattern()
      Returns the foreground pattern. The default value is null.
      Returns:
      the receiver's foreground pattern
      Throws:
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      Since:
      3.1
      See Also:

    • getGCData

      public GCData getGCData()
      Returns the GCData.

      IMPORTANT: This method is not part of the public API for GC. It is marked public only so that it can be shared within the packages provided by SWT. It is not available on all platforms, and should never be called from application code.

      Returns:
      the receiver's GCData
      Throws:
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      Since:
      3.2
      See Also:
      Restriction:
      This method is not intended to be referenced by clients.

    • getInterpolation

      public int getInterpolation()
      Returns the receiver's interpolation setting, which will be one of SWT.DEFAULT, SWT.NONE, SWT.LOW or SWT.HIGH.
      Returns:
      the receiver's interpolation setting
      Throws:
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      Since:
      3.1

    • 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
      Since:
      3.3

    • 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
      Since:
      3.1

    • 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:
      3.1

    • 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
      Since:
      3.1

    • 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

    • 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

    • 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
      Since:
      2.1.2

    • 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:
      3.1
      See Also:

    • 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:
      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:

    • getXORMode

      public boolean getXORMode()
      Returns true if this GC is drawing in the mode where the resulting color in the destination is the exclusive or of the color values in the source and the destination, and false if it is drawing in the mode where the destination color is being replaced with the source color value.
      Returns:
      true true if the receiver is in XOR mode, and false otherwise
      Throws:
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

    • hashCode

      public int hashCode()
      Returns an integer hash code for the receiver. Any two objects that return true when passed to equals must return the same value for this method.
      Overrides:
      hashCode in class Object
      Returns:
      the receiver's hash
      Throws:
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      See Also:

    • isClipped

      public boolean isClipped()
      Returns true if the receiver has a clipping region set into it, and false otherwise. If this method returns false, the receiver will draw on all available space in the destination. If it returns true, it will draw only in the area that is covered by the region that can be accessed with getClipping(region).
      Returns:
      true if the GC has a clipping region, and false otherwise
      Throws:
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

    • isDisposed

      public boolean isDisposed()
      Returns true if the GC has been disposed, and false otherwise.

      This method gets the dispose state for the GC. When a GC has been disposed, it is an error to invoke any other method (except dispose()) using the GC.

      Specified by:
      isDisposed in class Resource
      Returns:
      true when the GC is disposed and false otherwise

    • 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:
      3.1
      See Also:

    • 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:
      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:
      3.1
      See Also:

    • 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
      Since:
      3.1
      See Also:

    • 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:
      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

    • setBackgroundPattern

      public void setBackgroundPattern(Pattern pattern)
      Sets the background pattern. The default value is null.

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

      Parameters:
      pattern - the new background pattern
      Throws:
      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:

    • 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

    • 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:
      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:
      3.1
      See Also:

    • 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

    • setClipping

      public void setClipping(Region region)
      Sets the area of the receiver which can be changed by drawing operations to the region specified by the argument. Specifying null for the region reverts the receiver's clipping area to its original value.
      Parameters:
      region - the clipping region or null
      Throws:
      IllegalArgumentException -
      • ERROR_INVALID_ARGUMENT - if the region has been disposed
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

    • setFillRule

      public void setFillRule(int rule)
      Sets the receiver's fill rule to the parameter, which must be one of SWT.FILL_EVEN_ODD or SWT.FILL_WINDING.
      Parameters:
      rule - the new fill rule
      Throws:
      IllegalArgumentException -
      • ERROR_INVALID_ARGUMENT - if the rule is not one of SWT.FILL_EVEN_ODD or SWT.FILL_WINDING
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      Since:
      3.1

    • 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:
      IllegalArgumentException -
      • ERROR_INVALID_ARGUMENT - if the font has been disposed
      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:
      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

    • setForegroundPattern

      public void setForegroundPattern(Pattern pattern)
      Sets the foreground pattern. The default value is null.

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

      Parameters:
      pattern - the new foreground pattern
      Throws:
      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:

    • setInterpolation

      public void setInterpolation(int interpolation)
      Sets the receiver's interpolation setting to the parameter, which must be one of SWT.DEFAULT, SWT.NONE, SWT.LOW or SWT.HIGH.

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

      Parameters:
      interpolation - the new interpolation setting
      Throws:
      IllegalArgumentException -
      • ERROR_INVALID_ARGUMENT - if the rule is not one of SWT.DEFAULT, SWT.NONE, SWT.LOW or SWT.HIGH
      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:

    • 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:
      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
      Since:
      3.3
      See Also:

    • setLineCap

      public void setLineCap(int cap)
      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:
      cap - the cap style to be used for drawing lines
      Throws:
      IllegalArgumentException -
      • ERROR_INVALID_ARGUMENT - if the style is not valid
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      Since:
      3.1

    • 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:
      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:
      3.1

    • setLineJoin

      public void setLineJoin(int join)
      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:
      join - the join style to be used for drawing lines
      Throws:
      IllegalArgumentException -
      • ERROR_INVALID_ARGUMENT - if the style is not valid
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      Since:
      3.1

    • 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:
      IllegalArgumentException -
      • ERROR_INVALID_ARGUMENT - if the style is not valid
      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.

      Note that line width of zero is used as a hint to indicate that the fastest possible line drawing algorithms should be used. This means that the output may be different from line width one and specially at high DPI it's not recommended to mix line width zero with other line widths.

      Parameters:
      lineWidth - the width of a line
      Throws:
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

    • setXORMode

      public void setXORMode(boolean xor)
      If the argument is true, puts the receiver in a drawing mode where the resulting color in the destination is the exclusive or of the color values in the source and the destination, and if the argument is false, puts the receiver in a drawing mode where the destination color is replaced with the source color value.
      Parameters:
      xor - if true, then xor mode is used, otherwise source copy mode is used
      Throws:
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

    • 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:
      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:
      3.1
      See Also:

    • 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:
      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:

    • stringExtent

      public Point stringExtent(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:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the string is null
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

    • textExtent

      public Point textExtent(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:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the string is null
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

    • textExtent

      public Point textExtent(String string, int flags)
      Returns the extent of the given string. Tab expansion, line delimiter and mnemonic processing are performed according to the specified flags, which can be a combination of:
      DRAW_DELIMITER
      draw multiple lines
      DRAW_TAB
      expand tabs
      DRAW_MNEMONIC
      underline the mnemonic character
      DRAW_TRANSPARENT
      transparent background

      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
      flags - the flags specifying how to process the text
      Returns:
      a point containing the extent of the string
      Throws:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the string is null
      SWTException -
      • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

    • toString

      public String toString()
      Returns a string containing a concise, human-readable description of the receiver.
      Overrides:
      toString in class Object
      Returns:
      a string representation of the receiver

    • win32_new

      public static GC win32_new(Drawable drawable, GCData data)
      Invokes platform specific functionality to allocate a new graphics context.

      IMPORTANT: This method is not part of the public API for GC. It is marked public only so that it can be shared within the packages provided by SWT. It is not available on all platforms, and should never be called from application code.

      Parameters:
      drawable - the Drawable for the receiver.
      data - the data for the receiver.
      Returns:
      a new GC
      Restriction:
      This method is not intended to be referenced by clients.

    • win32_new

      public static GC win32_new(long hDC, GCData data)
      Invokes platform specific functionality to wrap a graphics context.

      IMPORTANT: This method is not part of the public API for GC. It is marked public only so that it can be shared within the packages provided by SWT. It is not available on all platforms, and should never be called from application code.

      Parameters:
      hDC - the Windows HDC.
      data - the data for the receiver.
      Returns:
      a new GC
      Restriction:
      This method is not intended to be referenced by clients.

    • dispose

      public void dispose()
      Description copied from class: Resource
      Disposes of the operating system resources associated with this resource. Applications must dispose of all resources which they allocate. This method does nothing if the resource is already disposed.
      Overrides:
      dispose in class Resource