/*******************************************************************************
* Copyright (c) 2000, 2007 IBM Corporation and others.
* Portion Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).
* 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:
* IBM Corporation - initial API and implementation
* Nokia Corporation - Qt implementation
*******************************************************************************/
package org.eclipse.swt.graphics;
import org.eclipse.swt.SWT;
import org.eclipse.swt.internal.qt.GCData;
import org.eclipse.swt.internal.qt.OS;
import org.eclipse.swt.internal.qt.graphics.GraphicsContext;
import org.eclipse.swt.internal.qt.graphics.WindowSurface;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Internal_PackageSupport;
/**
* Class <code>GC</code> is where all of the drawing capabilities that are
* supported by SWT are located. Instances are used to draw on either an
* <code>Image</code>, a <code>Control</code>, or directly on a
* <code>Display</code>.
* <dl>
* <dt><b>Styles:</b></dt>
* <dd>LEFT_TO_RIGHT, RIGHT_TO_LEFT</dd>
* </dl>
*
* <p>
* 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.
* </p>
*
* <p>
* Application code must explicitly invoke the <code>GC.dispose()</code> method
* to release the operating system resources managed by each instance when those
* instances are no longer required. This is <em>particularly</em> important on
* Windows95 and Windows98 where the operating system has a limited number of
* device contexts available.
* </p>
*
* <p>
* Note: Only one of LEFT_TO_RIGHT and RIGHT_TO_LEFT may be specified.
* </p>
*
* @see org.eclipse.swt.events.PaintEvent
*/
public final class GC {
// FontMetrics
private final static int FM_ASCENT = 0;
private final static int FM_AVERAGE_CHAR_WIDTH = 1;
private final static int FM_DESCENT = 2;
private final static int FM_HEIGHT = 3;
private final static int FM_LEADING = 4;
private final static int FM_DATA_COUNT = 5;
// Configuration flags
final static int FOREGROUND = 1 << 0;
final static int BACKGROUND = 1 << 1;
final static int FONT = 1 << 2;
final static int LINE_STYLE = 1 << 3;
final static int LINE_CAP = 1 << 4;
final static int LINE_JOIN = 1 << 5;
final static int LINE_WIDTH = 1 << 6;
final static int LINE_MITERLIMIT = 1 << 7;
final static int BACKGROUND_BG = 1 << 8;
final static int DRAW_OFFSET = 1 << 9;
final static int DRAW = FOREGROUND | LINE_WIDTH | LINE_STYLE | LINE_CAP
| LINE_JOIN | LINE_MITERLIMIT | DRAW_OFFSET;
final static int FILL = BACKGROUND;
static int checkStyle(int style) {
if ((style & SWT.LEFT_TO_RIGHT) != 0) {
style &= ~SWT.RIGHT_TO_LEFT;
}
return style & (SWT.LEFT_TO_RIGHT | SWT.RIGHT_TO_LEFT);
}
int handle;
GCData data;
Color customForeground;
Color customBackground;
Drawable drawable;
/**
* Prevents uninitialized instances from being created outside the package.
*/
GC() {
}
/**
* 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.
* <p>
* You must dispose the graphics context when it is no longer required.
* </p>
*
* @param drawable
* the drawable to draw on
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the drawable is null</li>
* <li>ERROR_NULL_ARGUMENT - if there is no current device</li>
* <li>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
* </li>
* </ul>
* @exception SWTError
* <ul>
* <li>ERROR_NO_HANDLES if a handle could not be obtained for GC
* creation</li>
* <li>ERROR_THREAD_INVALID_ACCESS if not called from the thread
* that created the drawable</li>
* </ul>
*/
public GC(Drawable drawable) {
this(drawable, 0);
}
/**
* 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.
* <p>
* You must dispose the graphics context when it is no longer required.
* </p>
*
* @param drawable
* the drawable to draw on
* @param style
* the style of GC to construct
*
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the drawable is null</li>
* <li>ERROR_NULL_ARGUMENT - if there is no current device</li>
* <li>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
* </li>
* </ul>
* @exception SWTError
* <ul>
* <li>ERROR_NO_HANDLES if a handle could not be obtained for GC
* creation</li>
* <li>ERROR_THREAD_INVALID_ACCESS if not called from the thread
* that created the drawable</li>
* </ul>
*
*/
public GC(Drawable drawable, int style) {
if (drawable == null) {
SWT.error(SWT.ERROR_NULL_ARGUMENT);
}
GCData data = new GCData();
data.style = checkStyle(style);
int gcHandle = drawable.internal_new_GC(data);
try {
init(drawable, data, gcHandle);
} catch (Error e) {
drawable.internal_dispose_GC(data);
throw e;
}
}
/*
* Here it's checked based on the data.state flags which gc attributes need to
* be configured. State flags are set when configuration is up-to-date and
* cleared when configuration is invalidated.
*/
void checkGC(int mask) {
int state = data.state;
if ((state & mask) == mask)
return;
state = (state ^ mask) & mask; // take out bits not in mask
data.state |= mask;
if((data.state & FOREGROUND) != 0) {
if ((data.style & SWT.MIRRORED) != 0) {
int width = OS.QPaintDevice_width(data.drawable);
data.internalGc.resetTransform();
data.internalGc.translate(width - 1, 0);
data.internalGc.scale(-1, 1);
}
}
}
/**
* Copies a rectangular area of the receiver at the specified position into the
* image, which must be of type <code>SWT.BITMAP</code>.
*
* @param image
* the image to copy into
* @param x
* the x coordinate in the receiver of the area to be copied
* @param y
* the y coordinate in the receiver of the area to be copied
*
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the image is null</li>
* <li>ERROR_INVALID_ARGUMENT - if the image is not a bitmap or
* has been disposed</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public void copyArea(Image image, int x, int y) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (image == null) {
SWT.error(SWT.ERROR_NULL_ARGUMENT);
}
if (image.type != SWT.BITMAP || image.isDisposed()) {
SWT.error(SWT.ERROR_INVALID_ARGUMENT);
}
// Reset all mirroring transformation and calculate the mirrored coordinates
// manually.
if ((data.style & SWT.MIRRORED) != 0) {
data.internalGc.resetTransform();
data.state = ~FOREGROUND;
int clientWidth = OS.QPaintDevice_width(data.drawable);
x = clientWidth - x - image.getBounds().width;
}
data.internalGc.copyArea(image.getImage(), x, y);
}
/**
* Copies a rectangular area of the receiver at the source position onto the
* receiver at the destination position.
*
* @param srcX
* the x coordinate in the receiver of the area to be copied
* @param srcY
* the y coordinate in the receiver of the area to be copied
* @param width
* the width of the area to copy
* @param height
* the height of the area to copy
* @param destX
* the x coordinate in the receiver of the area to copy to
* @param destY
* the y coordinate in the receiver of the area to copy to
*
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public void copyArea(int srcX, int srcY, int width, int height, int destX,
int destY) {
copyArea(srcX, srcY, width, height, destX, destY, true);
}
/**
* Copies a rectangular area of the receiver at the source
* position onto the receiver at the destination position.
*
* @param srcX the x coordinate in the receiver of the area to be copied
* @param srcY the y coordinate in the receiver of the area to be copied
* @param width the width of the area to copy
* @param height the height of the area to copy
* @param destX the x coordinate in the receiver of the area to copy to
* @param destY the y coordinate in the receiver of the area to copy to
* @param paint if <code>true</code> paint events will be generated for old and obscured areas
*
* @exception SWTException <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
* </ul>
*
* @since 3.1
*/
public void copyArea(int srcX, int srcY, int width, int height, int destX, int destY, boolean paint) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (width <= 0 || height <= 0) {
return;
}
int deltaX = destX - srcX;
int deltaY = destY - srcY;
if (deltaX == 0 && deltaY == 0) {
return;
}
// Reset all mirroring transformation and calculate the mirrored coordinates
// manually.
if ((data.style & SWT.MIRRORED) != 0) {
data.internalGc.resetTransform();
data.state = ~FOREGROUND;
int clientWidth = OS.QPaintDevice_width(data.drawable);
srcX = clientWidth - srcX - width;
destX = clientWidth - destX - width;
}
data.internalGc.copyArea(srcX, srcY, width, height, destX, destY, paint);
}
/**
* Disposes of the operating system resources associated with the graphics
* context. Applications must dispose of all the GCs which they allocate.
*
* @exception SWTError
* <ul>
* <li>ERROR_THREAD_INVALID_ACCESS if not called from the thread
* that created the drawable</li>
*/
public void dispose() {
final Display display = (Display)data.device;
if(display.getThread() != Thread.currentThread()) {
SWT.error(SWT.ERROR_THREAD_INVALID_ACCESS);
}
if (drawable != null && handle != 0) {
if (data.buffered && (drawable instanceof Control)) {
display.syncExec(new Runnable() {
public void run() {
((Control) drawable).redraw();
while (display.readAndDispatch())
;
}
});
}
drawable.internal_dispose_GC(data);
}
data.destroy();
handle = SWT.NULL;
customForeground = null;
customBackground = null;
drawable = null;
}
/**
* Draws the outline of a circular or elliptical arc within the specified
* rectangular area.
* <p>
* The resulting arc begins at <code>startAngle</code> and extends for <code>
* arcAngle</code> 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.
* </p>
* <p>
* The center of the arc is the center of the rectangle whose origin is (<code>x
* </code>, <code>y</code>) and whose size is specified by the <code>width
* </code> and <code>height</code> arguments.
* </p>
* <p>
* The resulting arc covers an area <code>width + 1</code> pixels wide by <code>
* height + 1</code> pixels tall.
* </p>
*
* @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
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public void drawArc(int x, int y, int width, int height, int startAngle,
int arcAngle) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (width < 0) {
x = x + width;
width = -width;
}
if (height < 0) {
y = y + height;
height = -height;
}
if (width == 0 || height == 0 || arcAngle == 0) {
return;
}
checkGC(FOREGROUND);
data.internalGc.drawArc(x, y, width, height, startAngle, arcAngle);
}
/**
* Draws a rectangle, based on the specified arguments, which has the appearance
* of the platform's <em>focus rectangle</em> 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
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*
* @see #drawRectangle(int, int, int, int)
*/
public void drawFocus(int x, int y, int width, int height) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
checkGC(FOREGROUND);
data.internalGc.drawFocus(x, y, width, height);
}
/**
* 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
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the image is null</li>
* <li>ERROR_INVALID_ARGUMENT - if the image has been disposed</li>
* <li>ERROR_INVALID_ARGUMENT - if the given coordinates are
* outside the bounds of the image</li>
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
* @exception SWTError
* <ul>
* <li>ERROR_NO_HANDLES - if no handles are available to perform
* the operation</li>
* </ul>
*/
public void drawImage(Image image, int x, int y) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (image == null) {
SWT.error(SWT.ERROR_NULL_ARGUMENT);
}
if (image.isDisposed()) {
SWT.error(SWT.ERROR_INVALID_ARGUMENT);
}
// Reset all mirroring transformation and calculate the mirrored coordinates
// manually.
if ((data.style & SWT.MIRRORED) != 0) {
data.internalGc.resetTransform();
data.state = ~FOREGROUND;
int clientWidth = OS.QPaintDevice_width(data.drawable);
x = clientWidth - x - image.getBounds().width;
}
data.internalGc.drawImage(image.getImage(), x, y);
}
/**
* 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
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the image is null</li>
* <li>ERROR_INVALID_ARGUMENT - if the image has been disposed</li>
* <li>ERROR_INVALID_ARGUMENT - if any of the width or height
* arguments are negative.
* <li>ERROR_INVALID_ARGUMENT - if the source rectangle is not
* contained within the bounds of the source image</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
* @exception SWTError
* <ul>
* <li>ERROR_NO_HANDLES - if no handles are available to perform
* the operation</li>
* </ul>
*/
public void drawImage(Image image, int srcX, int srcY, int srcWidth,
int srcHeight, int destX, int destY, int destWidth, int destHeight) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (srcWidth == 0 || srcHeight == 0 || destWidth == 0 || destHeight == 0) {
return;
}
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);
}
// Reset all mirroring transformation and calculate the mirrored coordinates
// manually.
if ((data.style & SWT.MIRRORED) != 0) {
data.internalGc.resetTransform();
data.state = ~FOREGROUND;
int clientWidth = OS.QPaintDevice_width(data.drawable);
srcX = image.getBounds().width - srcX - srcWidth;
destX = clientWidth - destX - destWidth;
}
data.internalGc.drawImage(image.getImage(), destX, destY,
destWidth, destHeight, srcX, srcY, srcWidth, srcHeight);
}
/**
* Draws a line, using the foreground color, between the points (<code>x1</code>
* , <code>y1</code>) and (<code>x2</code>, <code>y2</code>).
*
* @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
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public void drawLine(int x1, int y1, int x2, int y2) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
checkGC(FOREGROUND);
data.internalGc.drawLine(x1, y1, x2, y2);
}
/**
* Draws the outline of an oval, using the foreground color, within the
* specified rectangular area.
* <p>
* The result is a circle or ellipse that fits within the rectangle specified by
* the <code>x</code>, <code>y</code>, <code>width</code>, and
* <code>height</code> arguments.
* </p>
* <p>
* The oval covers an area that is <code>width + 1</code> pixels wide and
* <code>height + 1</code> pixels tall.
* </p>
*
* @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
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public void drawOval(int x, int y, int width, int height) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (width < 0) {
x = x + width;
width = -width;
}
if (height < 0) {
y = y + height;
height = -height;
}
checkGC(FOREGROUND);
data.internalGc.drawEllipse(x, y, width, height);
}
/**
* Draws a pixel, using the foreground color, at the specified point (
* <code>x</code>, <code>y</code>).
* <p>
* Note that the receiver's line attributes do not affect this operation.
* </p>
*
* @param x
* the point's x coordinate
* @param y
* the point's y coordinate
*
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*
* @since 3.0
*/
public void drawPoint(int x, int y) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
checkGC(FOREGROUND);
data.internalGc.drawPoint(x, y);
}
/**
* 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
* <ul>
* <li>ERROR_NULL_ARGUMENT if pointArray is null</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public void drawPolygon(int[] pointArray) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (pointArray == null) {
SWT.error(SWT.ERROR_NULL_ARGUMENT);
}
checkGC(FOREGROUND);
data.internalGc.drawPolygon(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.
*
* @param pointArray
* an array of alternating x and y values which are the corners of
* the polyline
*
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the point array is null</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public void drawPolyline(int[] pointArray) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (pointArray == null) {
SWT.error(SWT.ERROR_NULL_ARGUMENT);
}
checkGC(FOREGROUND);
data.internalGc.drawPolyline(pointArray);
}
/**
* 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
* <code>x</code> and <code>x + width</code>. The top and bottom edges are at
* <code>y</code> and <code>y + height</code>.
*
* @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
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public void drawRectangle(int x, int y, int width, int height) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (width < 0) {
x = x + width;
width = -width;
}
if (height < 0) {
y = y + height;
height = -height;
}
checkGC(FOREGROUND);
data.internalGc.drawRect(x, y, width, height);
}
/**
* Draws the outline of the specified rectangle, using the receiver's foreground
* color. The left and right edges of the rectangle are at <code>rect.x</code>
* and <code>rect.x + rect.width</code>. The top and bottom edges are at
* <code>rect.y</code> and <code>rect.y + rect.height</code>.
*
* @param rect
* the rectangle to draw
*
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the rectangle is null</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
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 round-cornered rectangle specified by the arguments,
* using the receiver's foreground color. The left and right edges of the
* rectangle are at <code>x</code> and <code>x + width</code>. The top and
* bottom edges are at <code>y</code> and <code>y + height</code>. The
* <em>roundness</em> of the corners is specified by the <code>arcWidth</code>
* and <code>arcHeight</code> 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
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public void drawRoundRectangle(int x, int y, int width, int height,
int arcWidth, int arcHeight) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
checkGC(FOREGROUND);
data.internalGc.drawRoundRect(x, y, width, height, arcWidth, arcHeight);
}
/**
* 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
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the string is null</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
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
* <code>isTransparent</code> is <code>true</code>, 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 <code>true</code> the background will be transparent, otherwise
* it will be opaque
*
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the string is null</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public void drawString(String string, int x, int y, boolean isTransparent) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (string == null) {
SWT.error(SWT.ERROR_NULL_ARGUMENT);
}
if (string.length() == 0) {
return;
}
// Reset all mirroring transformation and calculate the mirrored coordinates
// manually.
if ((data.style & SWT.MIRRORED) != 0) {
data.internalGc.resetTransform();
data.state = ~FOREGROUND;
int clientWidth = OS.QPaintDevice_width(data.drawable);
int box[] = new int[4];
data.internalGc
.getTextBoundingBox(
box,
string,
(GraphicsContext.ALIGNMENT_LEFT | GraphicsContext.ALIGNMENT_TOP),
GraphicsContext.TEXT_SINGLE_LINE);
x = clientWidth - x - box[GraphicsContext.RECT_WIDTH];
}
data.internalGc.drawString(string, x, y, isTransparent);
}
/**
* 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
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the string is null</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
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, line delimiter and mnemonic processing are performed
* according to the specified flags. If <code>flags</code> includes
* <code>DRAW_TRANSPARENT</code>, 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.
* <p>
* The parameter <code>flags</code> may be a combination of:
* <dl>
* <dt><b>DRAW_DELIMITER</b></dt>
* <dd>draw multiple lines</dd>
* <dt><b>DRAW_TAB</b></dt>
* <dd>expand tabs</dd>
* <dt><b>DRAW_MNEMONIC</b></dt>
* <dd>underline the mnemonic character</dd>
* <dt><b>DRAW_TRANSPARENT</b></dt>
* <dd>transparent background</dd>
* </dl>
* </p>
*
* @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
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the string is null</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public void drawText(String string, int x, int y, int flags) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (string == null) {
SWT.error(SWT.ERROR_NULL_ARGUMENT);
}
if (string.length() == 0) {
return;
}
int translatedFlags = 0;
boolean isTransparent = false;
if ((flags & SWT.DRAW_DELIMITER) == 0) {
translatedFlags |= GraphicsContext.TEXT_SINGLE_LINE;
}
if ((flags & SWT.DRAW_TAB) != 0) {
translatedFlags |= GraphicsContext.TEXT_EXPAND_TABS;
}
if ((flags & SWT.DRAW_MNEMONIC) != 0) {
translatedFlags |= GraphicsContext.TEXT_SHOW_MNEMONIC;
}
if ((flags & SWT.DRAW_TRANSPARENT) != 0) {
isTransparent = true;
}
// Reset all mirroring transformation and calculate the mirrored coordinates
// manually.
if ((data.style & SWT.MIRRORED) != 0) {
data.internalGc.resetTransform();
data.state = ~FOREGROUND;
int clientWidth = OS.QPaintDevice_width(data.drawable);
int box[] = new int[4];
data.internalGc
.getTextBoundingBox(
box,
string,
(GraphicsContext.ALIGNMENT_HCENTER | GraphicsContext.ALIGNMENT_LEFT),
translatedFlags);
x = clientWidth - x - box[GraphicsContext.RECT_WIDTH];
}
data.internalGc
.drawString(
string,
x,
y,
0,
0,
(GraphicsContext.ALIGNMENT_HCENTER | GraphicsContext.ALIGNMENT_LEFT),
translatedFlags, isTransparent);
}
/*
* Ends external rendering session.
*/
void endExternalRendering() {
if (drawable instanceof Control) {
Internal_PackageSupport.endWindowSurfaceSession((Control)drawable);
}
}
/**
* Compares the argument to the receiver, and returns true if they represent the
* <em>same</em> object using a class specific comparison.
*
* @param object
* the object to compare with this object
* @return <code>true</code> if the object is the same as this object and
* <code>false</code> otherwise
*
* @see #hashCode
*/
public boolean equals(Object object) {
if (object == this) {
return true;
}
if (!(object instanceof GC)) {
return false;
}
return handle == ((GC) object).handle;
}
/**
* Fills the interior of a circular or elliptical arc within the specified
* rectangular area, with the receiver's background color.
* <p>
* The resulting arc begins at <code>startAngle</code> and extends for
* <code>arcAngle</code> 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.
* </p>
* <p>
* The center of the arc is the center of the rectangle whose origin is (
* <code>x</code>, <code>y</code>) and whose size is specified by the
* <code>width</code> and <code>height</code> arguments.
* </p>
* <p>
* The resulting arc covers an area <code>width + 1</code> pixels wide by
* <code>height + 1</code> pixels tall.
* </p>
*
* @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
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*
* @see #drawArc
*/
public void fillArc(int x, int y, int width, int height, int startAngle,
int arcAngle) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (width < 0) {
x = x + width;
width = -width;
}
if (height < 0) {
y = y + height;
height = -height;
}
if (width == 0 || height == 0 || arcAngle == 0) {
return;
}
checkGC(FOREGROUND);
data.internalGc.fillArc(x, y, width, height, startAngle, arcAngle);
}
/**
* 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
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*
* @see #drawRectangle(int, int, int, int)
*/
public void fillGradientRectangle(int x, int y, int width, int height,
boolean vertical) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if ((width == 0) || (height == 0)) {
return;
}
boolean swapColors = false;
if (width < 0) {
if (!vertical) {
swapColors = true;
}
width = Math.abs(width);
}
if (height < 0) {
if (vertical) {
swapColors = true;
}
height = Math.abs(height);
}
checkGC(FOREGROUND);
data.internalGc.fillGradientRect(x, y, width, height, vertical, swapColors);
}
/**
* 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
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*
* @see #drawOval
*/
public void fillOval(int x, int y, int width, int height) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (width < 0) {
x = x + width;
width = -width;
}
if (height < 0) {
y = y + height;
height = -height;
}
checkGC(FOREGROUND);
data.internalGc.fillEllipse(x, y, width, height);
}
/**
* 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
* <ul>
* <li>ERROR_NULL_ARGUMENT if pointArray is null</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*
* @see #drawPolygon
*/
public void fillPolygon(int[] pointArray) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (pointArray == null) {
SWT.error(SWT.ERROR_NULL_ARGUMENT);
}
checkGC(FOREGROUND);
data.internalGc.fillPolygon(pointArray);
}
/**
* 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
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*
* @see #drawRectangle(int, int, int, int)
*/
public void fillRectangle(int x, int y, int width, int height) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (width < 0) {
x = x + width;
width = -width;
}
if (height < 0) {
y = y + height;
height = -height;
}
checkGC(FOREGROUND);
data.internalGc.fillRect(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
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the rectangle is null</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*
* @see #drawRectangle(int, int, int, int)
*/
public void fillRectangle(Rectangle rect) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (rect == null) {
SWT.error(SWT.ERROR_NULL_ARGUMENT);
}
fillRectangle(rect.x, rect.y, rect.width, rect.height);
}
/**
* 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
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*
* @see #drawRoundRectangle
*/
public void fillRoundRectangle(int x, int y, int width, int height,
int arcWidth, int arcHeight) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
checkGC(FOREGROUND);
data.internalGc.fillRoundRect(x, y, width, height, arcWidth, arcHeight);
}
/**
* Returns the <em>advance width</em> of the specified character in the font
* which is currently selected into the receiver.
* <p>
* The advance width is defined as the horizontal distance the cursor should
* move after printing the character in the selected font.
* </p>
*
* @param ch
* the character to measure
* @return the distance in the x direction to move past the character before
* painting the next
*
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public int getAdvanceWidth(char ch) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
return data.internalGc.getAdvancedCharacterWidth(ch);
}
/**
* Returns the receiver's alpha value. Default alpha value is 0xFF, fully opaque
*
*
* @return the alpha value
*
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public int getAlpha() {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
return data.alpha;
}
/**
* Returns the background color.
*
* @return the receiver's background color
*
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public Color getBackground() {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
return customBackground != null ? customBackground : data.background;
}
/**
* Returns the width of the specified character in the font selected into the
* receiver.
* <p>
* The width is defined as the space taken up by the actual character, not
* including the leading and tailing whitespace or overhang.
* </p>
*
* @param ch
* the character to measure
* @return the width of the character
*
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public int getCharWidth(char ch) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
return data.internalGc.getCharacterWidth(ch);
}
/**
* 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
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public Rectangle getClipping() {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
checkGC(FOREGROUND);
if (data.clippingRect == null) {
int[] clip = new int[4];
data.internalGc.getClip(clip);
data.clippingRect = new Rectangle(clip[GraphicsContext.RECT_X],
clip[GraphicsContext.RECT_Y], clip[GraphicsContext.RECT_WIDTH],
clip[GraphicsContext.RECT_HEIGHT]);
}
return new Rectangle(data.clippingRect.x, data.clippingRect.y,
data.clippingRect.width, data.clippingRect.height);
}
/**
* Returns the font currently being used by the receiver to draw and measure
* text.
*
* @return the receiver's font
*
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public Font getFont() {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
return data.font;
}
/**
* Returns a FontMetrics which contains information about the font currently
* being used by the receiver to draw and measure text. Note that if the font is
* changed later, the font metrics object is not updated accordingly.
*
* @return font metrics for the receiver's font
*
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public FontMetrics getFontMetrics() {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
// Read the FontMetrics data from the native
int fmData[] = new int[FM_DATA_COUNT];
data.internalGc.getFontMetricsData(fmData, 0, false);
// Create and fill up FonMetrics object.
FontMetrics fm = new FontMetrics();
fm.ascent = fmData[FM_ASCENT];
fm.averageCharWidth = fmData[FM_AVERAGE_CHAR_WIDTH];
fm.descent = fmData[FM_DESCENT];
fm.height = fmData[FM_HEIGHT];
fm.leading = fmData[FM_LEADING];
return fm;
}
/**
* Returns the receiver's foreground color.
*
* @return the color used for drawing foreground things
*
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public Color getForeground() {
if (isDisposed()) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
return customForeground != null ? customForeground : data.foreground;
}
/**
* Returns the GCData.
* <p>
* <b>IMPORTANT:</b> This method is <em>not</em> part of the public API for
* <code>GC</code>. 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.
* </p>
*
* @return the receiver's GCData
*
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*
* @see GCData
*
* @since 3.2
*/
public GCData getGCData() {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
return data;
}
/**
* Returns the receiver's line style, which will be one of the constants
* <code>SWT.LINE_SOLID</code>, <code>SWT.LINE_DASH</code>,
* <code>SWT.LINE_DOT</code>, <code>SWT.LINE_DASHDOT</code> or
* <code>SWT.LINE_DASHDOTDOT</code>.
*
* @return the style used for drawing lines
*
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public int getLineStyle() {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (data.lineStyle == GCData.NOT_DEFINED) {
data.lineStyle = GCData.translateStrokeStyle(data.internalGc
.getStrokeStyle(), false);
}
return data.lineStyle;
}
/**
* Returns the width that will be used when drawing lines for all of the figure
* drawing operations (that is, <code>drawLine</code>,
* <code>drawRectangle</code>, <code>drawPolyline</code>, and so forth.
*
* @return the receiver's line width
*
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public int getLineWidth() {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (data.lineWidth == GCData.NOT_DEFINED) {
data.lineWidth = data.internalGc.getStrokeWidth();
}
return data.lineWidth;
}
/**
* Returns the receiver's style information.
* <p>
* Note that the value which is returned by this method <em>may
* not match</em> 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.
* </p>
*
* @return the style bits. Possible values are:
* <ul>
* <li>LEFT_TO_RIGHT</li>
* <li>RIGHT_TO_LEFT</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*
* @since 2.1.2
*/
public int getStyle() {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
return data.style;
}
/**
* Returns <code>true</code> if this GC is drawing in the mode where the
* resulting color in the destination is the <em>exclusive or</em> of the color
* values in the source and the destination, and <code>false</code> if it is
* drawing in the mode where the destination color is being replaced with the
* source color value.
*
* @return <code>true</code> true if the receiver is in XOR mode, and false
* otherwise
*
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public boolean getXORMode() {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (data.xorMode == GCData.NOT_DEFINED) {
data.xorMode = (data.internalGc.getBlendingMode() == GraphicsContext.BLENDING_MODE_XOR ? GCData.XOR_MODE_ON
: GCData.XOR_MODE_OFF);
}
return (data.xorMode == GCData.XOR_MODE_ON);
}
/*
* Getter for the window surface which is target of this
* GC instance.
* @return related WindowSurface instance if the target is widget,
* otherwise null, if e.g. the target is instance of Image.
*/
WindowSurface getWindowSurface() {
if (drawable instanceof Control) {
return Internal_PackageSupport.getWindowsurface(((Control)drawable).getShell());
} else {
return null;
}
}
/**
* Returns an integer hash code for the receiver. Any two objects that return
* <code>true</code> when passed to <code>equals</code> must return the same
* value for this method.
*
* @return the receiver's hash
*
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*
* @see #equals
*/
public int hashCode() {
return handle;
}
void init(Drawable drawable, GCData data, int /* long */gcHandle) {
this.drawable = drawable;
this.data = data;
this.handle = gcHandle;
if (data.foreground == null) {
data.foreground = data.device.getSystemColor(SWT.COLOR_BLACK);
}
if (data.background == null) {
data.background = data.device.getSystemColor(SWT.COLOR_WHITE);
}
data.internalGc.setForegroundColor(data.foreground.getRed(),
data.foreground.getGreen(), data.foreground.getBlue());
data.internalGc.setBackgroundColor(data.background.getRed(),
data.background.getGreen(), data.background.getBlue());
this.drawable = drawable;
this.data = data;
handle = gcHandle;
}
/**
* Returns <code>true</code> if the receiver has a clipping region set into it,
* and <code>false</code> 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 <code>getClipping(region)</code>.
*
* @return <code>true</code> if the GC has a clipping region, and
* <code>false</code> otherwise
*
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public boolean isClipped() {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
return data.internalGc.hasClipping();
}
/**
* Returns <code>true</code> if the GC has been disposed, and <code>false</code>
* otherwise.
* <p>
* This method gets the dispose state for the GC. When a GC has been disposed,
* it is an error to invoke any other method using the GC.
*
* @return <code>true</code> when the GC is disposed and <code>false</code>
* otherwise
*/
public boolean isDisposed() {
return handle == 0;
}
/**
* Sets the receiver's alpha value.
* <p>
* This operation requires the operating system's advanced graphics subsystem
* which may not be available on some platforms.
* </p>
*
* @param alpha
* the alpha value
*
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not
* available</li>
* </ul>
*
* @see #getAdvanced
* @see #setAdvanced
*
* @since 3.1
*/
public void setAlpha(int alpha) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
data.alpha = alpha & 0xff;
data.internalGc.setForegroundAlpha(data.alpha);
data.internalGc.setBackgroundAlpha(data.alpha);
}
/**
* 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
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the color is null</li>
* <li>ERROR_INVALID_ARGUMENT - if the color has been disposed</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public void setBackground(Color color) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (color == null) {
SWT.error(SWT.ERROR_NULL_ARGUMENT);
}
if (color.isDisposed()) {
SWT.error(SWT.ERROR_INVALID_ARGUMENT);
}
this.customBackground = color;
data.internalGc.setBackgroundColor(color.getRed(), color.getGreen(), color
.getBlue());
}
/**
* Sets the area of the receiver which can be changed by drawing operations to
* the rectangular area specified by the arguments.
*
* @param x
* the x coordinate of the clipping rectangle
* @param y
* the y coordinate of the clipping rectangle
* @param width
* the width of the clipping rectangle
* @param height
* the height of the clipping rectangle
*
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public void setClipping(int x, int y, int width, int height) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (width < 0) {
x = x + width;
width = -width;
}
if (height < 0) {
y = y + height;
height = -height;
}
// Reset all mirroring transformation and calculate the mirrored coordinates
// manually.
if ((data.style & SWT.MIRRORED) != 0) {
data.internalGc.resetTransform();
data.state = ~FOREGROUND;
int clientWidth = OS.QPaintDevice_width(data.drawable);
x = clientWidth - x - (width + 1);
}
data.clippingRect = new Rectangle(x, y, width, height);
data.internalGc.setClip(x, y, width + 1, height, false);
}
/**
* Sets the area of the receiver which can be changed by drawing operations to
* the rectangular area specified by the argument. Specifying <code>null</code>
* for the rectangle reverts the receiver's clipping area to its original value.
*
* @param rect
* the clipping rectangle or <code>null</code>
*
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public void setClipping(Rectangle rect) {
if (handle == 0)
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
if (rect != null) {
setClipping(rect.x, rect.y, rect.width, rect.height);
} else {
data.internalGc.cancelClipping();
}
}
/**
* 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
* <ul>
* <li>ERROR_INVALID_ARGUMENT - if the font has been disposed</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public void setFont(Font font) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (font != null && font.isDisposed()) {
SWT.error(SWT.ERROR_INVALID_ARGUMENT);
}
data.font = font != null ? font : Font.qt_new(data.device, OS.SwtFontCache_cache(OS.QApplication_swt_font_new()));
data.internalGc.setFont(data.font.handle);
}
/**
* 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
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the color is null</li>
* <li>ERROR_INVALID_ARGUMENT - if the color has been disposed</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public void setForeground(Color color) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (color == null) {
SWT.error(SWT.ERROR_NULL_ARGUMENT);
}
if (color.isDisposed()) {
SWT.error(SWT.ERROR_INVALID_ARGUMENT);
}
customForeground = color;
data.internalGc.setForegroundColor(color.getRed(), color.getGreen(), color
.getBlue());
}
/**
* Sets the receiver's line style to the argument, which must be one of the
* constants <code>SWT.LINE_SOLID</code>, <code>SWT.LINE_DASH</code>,
* <code>SWT.LINE_DOT</code>, <code>SWT.LINE_DASHDOT</code> or
* <code>SWT.LINE_DASHDOTDOT</code>.
*
* @param lineStyle
* the style to be used for drawing lines
*
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_INVALID_ARGUMENT - if the style is not valid</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public void setLineStyle(int lineStyle) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (data.lineStyle == lineStyle) {
return;
}
data.internalGc
.setStrokeStyle(GCData.translateStrokeStyle(lineStyle, true));
data.lineStyle = lineStyle;
}
/**
* Sets the width that will be used when drawing lines for all of the figure
* drawing operations (that is, <code>drawLine</code>,
* <code>drawRectangle</code>, <code>drawPolyline</code>, and so forth.
* <p>
* 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.
* </p>
*
* @param lineWidth
* the width of a line
*
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public void setLineWidth(int lineWidth) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (data.lineWidth == lineWidth) {
return;
}
data.lineWidth = lineWidth;
data.internalGc.setStrokeWidth(lineWidth);
}
/**
* If the argument is <code>true</code>, puts the receiver in a drawing mode
* where the resulting color in the destination is the <em>exclusive or</em> of
* the color values in the source and the destination, and if the argument is
* <code>false</code>, puts the receiver in a drawing mode where the destination
* color is replaced with the source color value.
* <p>
* Note that this mode in fundamentally unsupportable on certain platforms,
* notably Carbon (Mac OS X). Clients that want their code to run on all
* platforms need to avoid this method.
* </p>
*
* @param xor
* if <code>true</code>, then <em>xor</em> mode is used, otherwise
* <em>source copy</em> mode is used
*
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public void setXORMode(boolean xor) {
if (handle == 0) {
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}
if (xor) {
if (data.xorMode == GCData.XOR_MODE_ON) {
return;
}
data.xorMode = GCData.XOR_MODE_ON;
data.internalGc.setBlendingMode(GraphicsContext.BLENDING_MODE_XOR);
} else {
if (data.xorMode == GCData.XOR_MODE_OFF) {
return;
}
data.xorMode = GCData.XOR_MODE_OFF;
data.internalGc.setBlendingMode(GraphicsContext.BLENDING_MODE_SRC_OVER);
}
}
/**
* Returns the extent of the given string. No tab expansion or carriage return
* processing will be performed.
* <p>
* The <em>extent</em> 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).
* </p>
*
* @param string
* the string to measure
* @return a point containing the extent of the string
*
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the string is null</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public Point stringExtent(String string) {
return textExtent(string, 0);
}
/*
* Starts external rendering session.
* The sessions must be opened before starting to render to the target outside GC.
* This is needed in order to open the rendering session to Qt window surface.
* Once rendering has completed the session must be closed with
* endExternalRendering() -call, which closes the window surface session.
*
* If the target of this GC is not Control, this call has no effect.
*
* @return the clip area of the GC in window coordinates
*/
Rectangle startExternalRendering() {
if (drawable instanceof Control) {
return Internal_PackageSupport.startWindowSurfaceSession((Control)drawable, getClipping());
}
return null;
}
/**
* Returns the extent of the given string. Tab expansion and carriage return
* processing are performed.
* <p>
* The <em>extent</em> 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).
* </p>
*
* @param string
* the string to measure
* @return a point containing the extent of the string
*
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the string is null</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public Point textExtent(String string) {
return textExtent(string, SWT.DRAW_DELIMITER | SWT.DRAW_TAB);
}
/**
* 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:
* <dl>
* <dt><b>DRAW_DELIMITER</b></dt>
* <dd>draw multiple lines</dd>
* <dt><b>DRAW_TAB</b></dt>
* <dd>expand tabs</dd>
* <dt><b>DRAW_MNEMONIC</b></dt>
* <dd>underline the mnemonic character</dd>
* <dt><b>DRAW_TRANSPARENT</b></dt>
* <dd>transparent background</dd>
* </dl>
* <p>
* The <em>extent</em> 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).
* </p>
*
* @param string
* the string to measure
* @param flags
* the flags specifying how to process the text
* @return a point containing the extent of the string
*
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the string is null</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
* </li>
* </ul>
*/
public Point textExtent(String string, int flags) {
if (handle == 0)
SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
if (string == null)
SWT.error(SWT.ERROR_NULL_ARGUMENT);
int[] box = new int[4];
int textFlags = 0;
if ((flags & SWT.DRAW_DELIMITER) == 0) {
textFlags |= GraphicsContext.TEXT_SINGLE_LINE;
}
if ((flags & SWT.DRAW_TAB) != 0) {
textFlags |= GraphicsContext.TEXT_EXPAND_TABS;
}
if ((flags & SWT.DRAW_MNEMONIC) != 0) {
textFlags |= GraphicsContext.TEXT_SHOW_MNEMONIC;
}
data.internalGc.getTextBoundingBox(box, string,
GraphicsContext.ALIGNMENT_LEFT, textFlags);
return new Point(box[GraphicsContext.RECT_WIDTH],
box[GraphicsContext.RECT_HEIGHT]);
}
/**
* Returns a string containing a concise, human-readable description of the
* receiver.
*
* @return a string representation of the receiver
*/
public String toString() {
if (isDisposed())
return "GC {*DISPOSED*}";
return "GC {" + handle + "}";
}
}