org.eclipse.swt.graphics.GC Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2010, 2012 EclipseSource and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* EclipseSource - initial API and implementation
******************************************************************************/
package org.eclipse.swt.graphics;
import java.io.IOException;
import java.io.NotSerializableException;
import java.io.ObjectOutputStream;
import org.eclipse.swt.SWT;
import org.eclipse.swt.SWTError;
import org.eclipse.swt.SWTException;
import org.eclipse.swt.widgets.Control;
/**
* 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.
*
*
*
*
* @see org.eclipse.swt.events.PaintEvent
*
* @since 1.3
*/
public class GC extends Resource {
private final GCDelegate delegate;
private boolean advanced;
private int antialias;
private int textAntialias;
/**
* 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.
*
* @param drawable the drawable to draw on
* @exception 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
*
* @exception 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
*
*/
public GC( Drawable drawable ) {
this( drawable, SWT.NONE );
}
/**
* 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.
*
*
* @param drawable the drawable to draw on
* @param style the style of GC to construct
*
* @exception 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
*
* @exception 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
*
*/
public GC( Drawable drawable, int style ) {
super( determineDevice( drawable ) );
if( drawable == null ) {
SWT.error( SWT.ERROR_NULL_ARGUMENT );
}
delegate = determineDelegate( drawable );
antialias = SWT.DEFAULT;
textAntialias = SWT.DEFAULT;
}
/**
* 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.
*
* @param font the new font for the receiver, or null to indicate a default font
*
* @exception IllegalArgumentException
* - ERROR_INVALID_ARGUMENT - if the font has been disposed
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public void setFont( Font font ) {
checkDisposed();
if( font != null && font.isDisposed() ) {
SWT.error( SWT.ERROR_INVALID_ARGUMENT );
}
Font newFont = font != null ? font : delegate.getDefaultFont();
delegate.setFont( newFont );
}
/**
* Returns the font currently being used by the receiver
* to draw and measure text.
*
* @return the receiver's font
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public Font getFont() {
checkDisposed();
return delegate.getFont();
}
/**
* 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.
*
*
* @param ch the character to measure
* @return the width of the character
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public int getCharWidth( char ch ) {
checkDisposed();
return delegate.stringExtent( Character.toString( ch ) ).x;
}
/**
* 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).
*
*
* @param string the string to measure
* @return a point containing the extent of the string
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the string is null
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public Point stringExtent( String string ) {
checkDisposed();
if( string == null ) {
SWT.error( SWT.ERROR_NULL_ARGUMENT );
}
return delegate.stringExtent( 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).
*
*
* @param string the string to measure
* @return a point containing the extent of the string
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the string is null
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public Point textExtent( String string ) {
checkDisposed();
if( string == null ) {
SWT.error( SWT.ERROR_NULL_ARGUMENT );
}
return delegate.textExtent( string, 0 );
}
/**
* Returns a FontMetrics which contains information
* about the font currently being used by the receiver
* to draw and measure text.
*
* @return font metrics for the receiver's font
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public FontMetrics getFontMetrics() {
checkDisposed();
return new FontMetrics( delegate.getFont() );
}
/**
* Sets the background color. The background color is used
* for fill operations and as the background color when text
* is drawn.
*
* @param color the new background color for the receiver
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the color is null
* - ERROR_INVALID_ARGUMENT - if the color has been disposed
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public void setBackground( Color color ) {
checkDisposed();
if( color == null ) {
SWT.error( SWT.ERROR_NULL_ARGUMENT );
}
if( color.isDisposed() ) {
SWT.error( SWT.ERROR_INVALID_ARGUMENT );
}
delegate.setBackground( color );
}
/**
* Returns the background color.
*
* @return the receiver's background color
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public Color getBackground() {
checkDisposed();
return delegate.getBackground();
}
/**
* Sets the foreground color. The foreground color is used
* for drawing operations including when text is drawn.
*
* @param color the new foreground color for the receiver
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the color is null
* - ERROR_INVALID_ARGUMENT - if the color has been disposed
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public void setForeground( Color color ) {
checkDisposed();
if( color == null ) {
SWT.error( SWT.ERROR_NULL_ARGUMENT );
}
if( color.isDisposed() ) {
SWT.error( SWT.ERROR_INVALID_ARGUMENT );
}
delegate.setForeground( color );
}
/**
* Returns the receiver's foreground color.
*
* @return the color used for drawing foreground things
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public Color getForeground() {
checkDisposed();
return delegate.getForeground();
}
/**
* 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.
*
* @return the bounding rectangle of the clipping region
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public Rectangle getClipping() {
checkDisposed();
return delegate.getClipping();
}
/**
* 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.
*
* @param alpha the alpha value
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* - ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available
*
*/
public void setAlpha( int alpha ) {
checkDisposed();
if( alpha >= 0 && alpha <= 255 && delegate.getAlpha() != alpha ) {
delegate.setAlpha( alpha );
advanced = true;
}
}
/**
* Returns the receiver's alpha value. The alpha value
* is between 0 (transparent) and 255 (opaque).
*
* @return the alpha value
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public int getAlpha() {
checkDisposed();
return delegate.getAlpha();
}
/**
* 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.
*
* @param lineWidth the width of a line
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public void setLineWidth( int lineWidth ) {
checkDisposed();
if( delegate.getLineWidth() != lineWidth ) {
delegate.setLineWidth( lineWidth );
}
}
/**
* 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.
*
* @return the receiver's line width
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public int getLineWidth() {
checkDisposed();
return delegate.getLineWidth();
}
/**
* 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.
*
* @param lineCap the cap style to be used for drawing lines
*
* @exception IllegalArgumentException
* - ERROR_INVALID_ARGUMENT - if the style is not valid
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public void setLineCap( int lineCap ) {
checkDisposed();
if( delegate.getLineCap() != lineCap ) {
switch( lineCap ) {
case SWT.CAP_ROUND:
case SWT.CAP_FLAT:
case SWT.CAP_SQUARE:
break;
default:
SWT.error( SWT.ERROR_INVALID_ARGUMENT );
}
delegate.setLineCap( lineCap );
}
}
/**
* Returns the receiver's line cap style, which will be one
* of the constants SWT.CAP_FLAT, SWT.CAP_ROUND,
* or SWT.CAP_SQUARE.
*
* @return the cap style used for drawing lines
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public int getLineCap() {
checkDisposed();
return delegate.getLineCap();
}
/**
* 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.
*
* @param lineJoin the join style to be used for drawing lines
*
* @exception IllegalArgumentException
* - ERROR_INVALID_ARGUMENT - if the style is not valid
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public void setLineJoin( int lineJoin ) {
checkDisposed();
if( delegate.getLineJoin() != lineJoin ) {
switch( lineJoin ) {
case SWT.JOIN_MITER:
case SWT.JOIN_ROUND:
case SWT.JOIN_BEVEL:
break;
default:
SWT.error( SWT.ERROR_INVALID_ARGUMENT );
}
delegate.setLineJoin( lineJoin );
}
}
/**
* Returns the receiver's line join style, which will be one
* of the constants SWT.JOIN_MITER, SWT.JOIN_ROUND,
* or SWT.JOIN_BEVEL.
*
* @return the join style used for drawing lines
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public int getLineJoin() {
checkDisposed();
return delegate.getLineJoin();
}
/**
* Sets the receiver's line attributes.
*
* This operation requires the operating system's advanced
* graphics subsystem which may not be available on some
* platforms.
*
* @param attributes the line attributes
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the attributes is null
* - ERROR_INVALID_ARGUMENT - if any of the line attributes is not valid
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* - ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available
*
*
* @see LineAttributes
*/
public void setLineAttributes( LineAttributes attributes ) {
checkDisposed();
if( attributes == null ) {
SWT.error( SWT.ERROR_NULL_ARGUMENT );
}
setLineWidth( ( int )attributes.width );
setLineCap( attributes.cap );
setLineJoin( attributes.join );
advanced = true;
}
/**
* Returns the receiver's line attributes.
*
* @return the line attributes used for drawing lines
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public LineAttributes getLineAttributes() {
checkDisposed();
int lineWidth = delegate.getLineWidth();
int lineCap = delegate.getLineCap();
int lineJoin = delegate.getLineJoin();
return new LineAttributes( lineWidth, lineCap, lineJoin );
}
/**
* 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.
*
*
* @param advanced the new advanced graphics state
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @see #setAlpha
* @see #setAntialias
* @see #setLineAttributes
* @see #setTextAntialias
* @see #getAdvanced
*
* @since 1.4
*/
// * @see #setClipping(Path)
// * @see #setInterpolation
// * @see #setForegroundPattern
// * @see #setBackgroundPattern
// * @see #setTransform
public void setAdvanced( boolean advanced ) {
checkDisposed();
this.advanced = advanced;
if( !advanced ) {
delegate.setAlpha( 255 );
antialias = SWT.DEFAULT;
textAntialias = SWT.DEFAULT;
}
}
/**
* 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.
*
*
* @param antialias the anti-aliasing setting
*
* @exception IllegalArgumentException
* - ERROR_INVALID_ARGUMENT - if the parameter is not one of
SWT.DEFAULT,
* SWT.OFF or SWT.ON
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* - ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available
*
*
* @see #getAdvanced
* @see #setAdvanced
* @see #setTextAntialias
*
* @since 1.5
*/
public void setAntialias( int antialias ) {
if( antialias != SWT.DEFAULT && antialias != SWT.ON && antialias != SWT.OFF ) {
SWT.error( SWT.ERROR_INVALID_ARGUMENT );
}
this.antialias = antialias;
advanced = true;
}
/**
* 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.
*
* @return the anti-aliasing setting
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @see #getTextAntialias
*
* @since 1.5
*/
public int getAntialias() {
return 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.
*
*
* @param antialias the anti-aliasing setting
*
* @exception IllegalArgumentException
* - ERROR_INVALID_ARGUMENT - if the parameter is not one of
SWT.DEFAULT,
* SWT.OFF or SWT.ON
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* - ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available
*
*
* @see #getAdvanced
* @see #setAdvanced
* @see #setAntialias
*
* @since 1.5
*/
public void setTextAntialias( int antialias ) {
if( antialias != SWT.DEFAULT && antialias != SWT.ON && antialias != SWT.OFF ) {
SWT.error( SWT.ERROR_INVALID_ARGUMENT );
}
textAntialias = antialias;
advanced = true;
}
/**
* 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.
*
* @return the anti-aliasing setting
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @see #getAntialias
*
* @since 1.5
*/
public int getTextAntialias() {
return textAntialias;
}
/**
* 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.
*
*
* @return the advanced value
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @see #setAdvanced
*
* @since 1.4
*/
public boolean getAdvanced() {
checkDisposed();
return advanced;
}
/**
* Draws a line, using the foreground color, between the points
* (x1, y1) and (x2, y2).
*
* @param x1 the first point's x coordinate
* @param y1 the first point's y coordinate
* @param x2 the second point's x coordinate
* @param y2 the second point's y coordinate
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public void drawLine( int x1, int y1, int x2, int y2 )
{
checkDisposed();
delegate.drawLine( x1, y1, x2, y2 );
}
/**
* 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.
*
* @param rect the rectangle to draw
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the rectangle is null
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public void drawRectangle( Rectangle rect ) {
if( rect == null ) {
SWT.error( SWT.ERROR_NULL_ARGUMENT );
}
drawRectangle( rect.x, rect.y, rect.width, rect.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.
*
* @param x the x coordinate of the rectangle to be drawn
* @param y the y coordinate of the rectangle to be drawn
* @param width the width of the rectangle to be drawn
* @param height the height of the rectangle to be drawn
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public void drawRectangle( int x, int y, int width, int height )
{
checkDisposed();
drawRectangle( x, y, width, height, 0, 0, false );
}
/**
* 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.
*
* @param x the x coordinate of the rectangle
* @param y the y coordinate of the rectangle
* @param width the width of the rectangle
* @param height the height of the rectangle
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @see #drawRectangle(int, int, int, int)
*/
public void drawFocus( int x, int y, int width, int height )
{
drawRectangle( x, y, width, height );
}
/**
* Fills the interior of the specified rectangle, using the receiver's
* background color.
*
* @param rect the rectangle to be filled
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the rectangle is null
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @see #drawRectangle(int, int, int, int)
*/
public void fillRectangle( Rectangle rect ) {
if( rect == null ) {
SWT.error( SWT.ERROR_NULL_ARGUMENT );
}
fillRectangle( rect.x, rect.y, rect.width, rect.height );
}
/**
* Fills the interior of the rectangle specified by the arguments,
* using the receiver's background color.
*
* @param x the x coordinate of the rectangle to be filled
* @param y the y coordinate of the rectangle to be filled
* @param width the width of the rectangle to be filled
* @param height the height of the rectangle to be filled
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @see #drawRectangle(int, int, int, int)
*/
public void fillRectangle( int x, int y, int width, int height ) {
checkDisposed();
drawRectangle( x, y, width, height, 0, 0, true );
}
/**
* 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.
*
* @param x the x coordinate of the rectangle to be filled
* @param y the y coordinate of the rectangle to be filled
* @param width the width of the rectangle to be filled, may be negative
* (inverts direction of gradient if horizontal)
* @param height the height of the rectangle to be filled, may be negative
* (inverts direction of gradient if vertical)
* @param vertical if true sweeps from top to bottom, else
* sweeps from left to right
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @see #drawRectangle(int, int, int, int)
*/
public void fillGradientRectangle( int x, int y, int width, int height, boolean vertical )
{
checkDisposed();
if( width != 0 && height != 0 ) {
if( delegate.getBackground().equals( delegate.getForeground() ) ) {
fillRectangle( x, y, width, height );
} else {
fillGradientRect( x, y, width, height, vertical );
}
}
}
/**
* 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.
*
* @param x the x coordinate of the rectangle to be drawn
* @param y the y coordinate of the rectangle to be drawn
* @param width the width of the rectangle to be drawn
* @param height the height of the rectangle to be drawn
* @param arcWidth the width of the arc
* @param arcHeight the height of the arc
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public void drawRoundRectangle( int x, int y, int width, int height, int arcWidth, int arcHeight )
{
checkDisposed();
drawRectangle( x, y, width, height, arcWidth, arcHeight, false );
}
/**
* Fills the interior of the round-cornered rectangle specified by
* the arguments, using the receiver's background color.
*
* @param x the x coordinate of the rectangle to be filled
* @param y the y coordinate of the rectangle to be filled
* @param width the width of the rectangle to be filled
* @param height the height of the rectangle to be filled
* @param arcWidth the width of the arc
* @param arcHeight the height of the arc
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @see #drawRoundRectangle
*/
public void fillRoundRectangle( int x, int y, int width, int height, int arcWidth, int arcHeight )
{
checkDisposed();
drawRectangle( x, y, width, height, arcWidth, arcHeight, true );
}
/**
* 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.
*
*
* @param x the x coordinate of the upper left corner of the oval to be drawn
* @param y the y coordinate of the upper left corner of the oval to be drawn
* @param width the width of the oval to be drawn
* @param height the height of the oval to be drawn
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public void drawOval( int x, int y, int width, int height ) {
checkDisposed();
drawArc( x, y, width, height, 0, 360, false );
}
/**
* Fills the interior of an oval, within the specified
* rectangular area, with the receiver's background
* color.
*
* @param x the x coordinate of the upper left corner of the oval to be filled
* @param y the y coordinate of the upper left corner of the oval to be filled
* @param width the width of the oval to be filled
* @param height the height of the oval to be filled
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @see #drawOval
*/
public void fillOval( int x, int y, int width, int height ) {
checkDisposed();
drawArc( x, y, width, height, 0, 360, true );
}
/**
* 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.
*
*
* @param x the x coordinate of the upper-left corner of the arc to be drawn
* @param y the y coordinate of the upper-left corner of the arc to be drawn
* @param width the width of the arc to be drawn
* @param height the height of the arc to be drawn
* @param startAngle the beginning angle
* @param arcAngle the angular extent of the arc, relative to the start angle
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public void drawArc( int x, int y, int width, int height, int startAngle, int arcAngle ) {
checkDisposed();
drawArc( x, y, width, height, startAngle, arcAngle, false );
}
/**
* 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.
*
*
* @param x the x coordinate of the upper-left corner of the arc to be filled
* @param y the y coordinate of the upper-left corner of the arc to be filled
* @param width the width of the arc to be filled
* @param height the height of the arc to be filled
* @param startAngle the beginning angle
* @param arcAngle the angular extent of the arc, relative to the start angle
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @see #drawArc
*/
public void fillArc( int x, int y, int width, int height, int startAngle, int arcAngle ) {
checkDisposed();
drawArc( x, y, width, height, startAngle, arcAngle, true );
}
/**
* 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.
*
* @param pointArray an array of alternating x and y values which are the vertices of the polygon
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT if pointArray is null
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public void drawPolygon( int[] pointArray ) {
checkDisposed();
if( pointArray == null ) {
SWT.error( SWT.ERROR_NULL_ARGUMENT );
}
delegate.drawPolyline( pointArray, true, false );
}
/**
* 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.
*
* @param pointArray an array of alternating x and y values which are the vertices of the polygon
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT if pointArray is null
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*
* @see #drawPolygon
*/
public void fillPolygon( int[] pointArray ) {
checkDisposed();
if( pointArray == null ) {
SWT.error( SWT.ERROR_NULL_ARGUMENT );
}
delegate.drawPolyline( pointArray, true, true );
}
/**
* 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.
*
* @param pointArray an array of alternating x and y values which are the corners of the polyline
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the point array is null
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public void drawPolyline( int[] pointArray ) {
checkDisposed();
if( pointArray == null ) {
SWT.error( SWT.ERROR_NULL_ARGUMENT );
}
delegate.drawPolyline( pointArray, false, false );
}
/**
* 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.
*
*
* @param x the point's x coordinate
* @param y the point's y coordinate
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public void drawPoint( int x, int y ) {
checkDisposed();
delegate.drawPoint( x, y );
}
/**
* Draws the given image in the receiver at the specified
* coordinates.
*
* @param image the image to draw
* @param x the x coordinate of where to draw
* @param y the y coordinate of where to draw
*
* @exception 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
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
* @exception SWTError
* - ERROR_NO_HANDLES - if no handles are available to perform the operation
*
*/
public void drawImage( Image image, int x, int y) {
checkDisposed();
if( image == null ) {
SWT.error( SWT.ERROR_NULL_ARGUMENT );
}
if( image.isDisposed() ) {
SWT.error( SWT.ERROR_INVALID_ARGUMENT );
}
Rectangle src = new Rectangle( 0, 0, -1, -1 );
Rectangle dest = new Rectangle( x, y, -1, -1 );
delegate.drawImage( image, src, dest, true );
}
/**
* 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.
*
* @param image the source image
* @param srcX the x coordinate in the source image to copy from
* @param srcY the y coordinate in the source image to copy from
* @param srcWidth the width in pixels to copy from the source
* @param srcHeight the height in pixels to copy from the source
* @param destX the x coordinate in the destination to copy to
* @param destY the y coordinate in the destination to copy to
* @param destWidth the width in pixels of the destination rectangle
* @param destHeight the height in pixels of the destination rectangle
*
* @exception 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
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
* @exception SWTError
* - ERROR_NO_HANDLES - if no handles are available to perform the operation
*
*/
public void drawImage( Image image,
int srcX,
int srcY,
int srcWidth,
int srcHeight,
int destX,
int destY,
int destWidth,
int destHeight )
{
checkDisposed();
if( srcWidth != 0 && srcHeight != 0 && destWidth != 0 && destHeight != 0 ) {
if( srcX < 0
|| srcY < 0
|| srcWidth < 0
|| srcHeight < 0
|| destWidth < 0
|| destHeight < 0 )
{
SWT.error( SWT.ERROR_INVALID_ARGUMENT );
}
if( image == null ) {
SWT.error( SWT.ERROR_NULL_ARGUMENT );
}
if( image.isDisposed() ) {
SWT.error( SWT.ERROR_INVALID_ARGUMENT );
}
int imgWidth = image.getBounds().width;
int imgHeight = image.getBounds().height;
if( srcX + srcWidth > imgWidth || srcY + srcHeight > imgHeight ) {
SWT.error( SWT.ERROR_INVALID_ARGUMENT );
}
Rectangle src = new Rectangle( srcX, srcY, srcWidth, srcHeight );
Rectangle dest = new Rectangle( destX, destY, destWidth, destHeight );
delegate.drawImage( image, src, dest, false );
}
}
/**
* 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.
*
* @param string the string to be drawn
* @param x the x coordinate of the top left corner of the rectangular area where the string is to be drawn
* @param y the y coordinate of the top left corner of the rectangular area where the string is to be drawn
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the string is null
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public void drawString( String string, int x, int y ) {
drawString( string, x, y, false );
}
/**
* 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.
*
* @param string the string to be drawn
* @param x the x coordinate of the top left corner of the rectangular area where the string is to be drawn
* @param y the y coordinate of the top left corner of the rectangular area where the string is to be drawn
* @param isTransparent if true the background will be transparent, otherwise it will be opaque
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the string is null
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public void drawString( String string, int x, int y, boolean isTransparent )
{
int flags = isTransparent ? SWT.DRAW_TRANSPARENT : SWT.NONE;
drawText( string, x, y, flags );
}
/**
* 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.
*
* @param string the string to be drawn
* @param x the x coordinate of the top left corner of the rectangular area where the text is to be drawn
* @param y the y coordinate of the top left corner of the rectangular area where the text is to be drawn
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the string is null
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public void drawText( String string, int x, int y ) {
drawText( string, x, y, SWT.DRAW_DELIMITER | SWT.DRAW_TAB );
}
/**
* 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.
*
* @param string the string to be drawn
* @param x the x coordinate of the top left corner of the rectangular area where the text is to be drawn
* @param y the y coordinate of the top left corner of the rectangular area where the text is to be drawn
* @param isTransparent if true the background will be transparent, otherwise it will be opaque
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the string is null
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public void drawText( String string, int x, int y, boolean isTransparent ) {
int flags = SWT.DRAW_DELIMITER | SWT.DRAW_TAB;
if( isTransparent ) {
flags |= SWT.DRAW_TRANSPARENT;
}
drawText( string, x, y, 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
*
*
*
* @param string the string to be drawn
* @param x the x coordinate of the top left corner of the rectangular area where the text is to be drawn
* @param y the y coordinate of the top left corner of the rectangular area where the text is to be drawn
* @param flags the flags specifying how to process the text
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the string is null
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public void drawText( String string, int x, int y, int flags ) {
checkDisposed();
if( string == null ) {
SWT.error( SWT.ERROR_NULL_ARGUMENT );
}
if( string.length() != 0 ) {
delegate.drawText( string, x, y, flags );
}
}
/**
* 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.
*
*
* @return the style bits
*
* @exception SWTException
* - ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
*
*/
public int getStyle() {
checkDisposed();
return SWT.LEFT_TO_RIGHT;
}
GCDelegate getGCDelegate() {
return delegate;
}
static Rectangle checkBounds( int x, int y, int width, int height ) {
Rectangle result = new Rectangle( x, y, width, height );
if( width < 0 ) {
result.x = x + width;
result.width = -width;
}
if( height < 0 ) {
result.y = y + height;
result.height = -height;
}
return result;
}
private void checkDisposed() {
if( isDisposed() ) {
SWT.error( SWT.ERROR_GRAPHIC_DISPOSED );
}
}
private void drawArc( int x,
int y,
int width,
int height,
int startAngle,
int arcAngle,
boolean fill )
{
Rectangle bounds = checkBounds( x, y, width, height );
if( bounds.width != 0 && bounds.height != 0 && arcAngle != 0 ) {
delegate.drawArc( bounds, startAngle, arcAngle, fill );
}
}
private void drawRectangle( int x,
int y,
int width,
int height,
int arcWidth,
int arcHeight,
boolean fill )
{
Rectangle bounds = checkBounds( x, y, width, height );
if( bounds.width != 0 && bounds.height != 0 ) {
if( arcWidth == 0 || arcHeight == 0 ) {
delegate.drawRectangle( bounds, fill );
} else {
int absArcWidth = Math.abs( arcWidth );
int absArcHeight = Math.abs( arcHeight );
delegate.drawRoundRectangle( bounds, absArcWidth, absArcHeight, fill );
}
}
}
private void fillGradientRect( int x, int y, int width, int height, boolean vertical ) {
Rectangle bounds = new Rectangle( x, y, width, height );
delegate.fillGradientRectangle( bounds, vertical );
}
private static GCDelegate determineDelegate( Drawable drawable ) {
GCDelegate result = null;
// Assume that Drawable is either a Control or a Device
if( drawable instanceof Control ) {
result = new ControlGC( ( Control )drawable );
} else if( drawable instanceof Device ) {
result = new DeviceGC( ( Device )drawable );
}
return result;
}
private static Device determineDevice( Drawable drawable ) {
Device result = null;
if( drawable instanceof Control ) {
result = ( ( Control )drawable ).getDisplay();
} else if( drawable instanceof Device ) {
result = ( Device )drawable;
}
return result;
}
void writeObject( ObjectOutputStream stream ) throws IOException {
throw new NotSerializableException( getClass().getName() );
}
}