| /******************************************************************************* |
| * Copyright (c) 2000, 2016 IBM Corporation 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: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.swt.graphics; |
| |
| import org.eclipse.swt.*; |
| import org.eclipse.swt.internal.*; |
| import org.eclipse.swt.internal.cairo.*; |
| |
| /** |
| * Instances of this class represent patterns to use while drawing. Patterns |
| * can be specified either as bitmaps or gradients. |
| * <p> |
| * Application code must explicitly invoke the <code>Pattern.dispose()</code> |
| * method to release the operating system resources managed by each instance |
| * when those instances are no longer required. |
| * </p> |
| * <p> |
| * This class requires the operating system's advanced graphics subsystem |
| * which may not be available on some platforms. |
| * </p> |
| * |
| * @see <a href="http://www.eclipse.org/swt/snippets/#path">Path, Pattern snippets</a> |
| * @see <a href="http://www.eclipse.org/swt/examples.php">SWT Example: GraphicsExample</a> |
| * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a> |
| * |
| * @since 3.1 |
| */ |
| public class Pattern extends Resource { |
| |
| /** |
| * the OS resource for the Pattern |
| * (Warning: This field is platform dependent) |
| * <p> |
| * <b>IMPORTANT:</b> This field is <em>not</em> part of the SWT |
| * public API. It is marked public only so that it can be shared |
| * within the packages provided by SWT. It is not available on all |
| * platforms and should never be accessed from application code. |
| * </p> |
| * |
| * @noreference This field is not intended to be referenced by clients. |
| */ |
| public long /*int*/ handle; |
| |
| long /*int*/ surface; |
| |
| /** |
| * Constructs a new Pattern given an image. Drawing with the resulting |
| * pattern will cause the image to be tiled over the resulting area. |
| * <p> |
| * This operation requires the operating system's advanced |
| * graphics subsystem which may not be available on some |
| * platforms. |
| * </p> |
| * <p> |
| * You must dispose the pattern when it is no longer required. |
| * </p> |
| * |
| * @param device the device on which to allocate the pattern |
| * @param image the image that the pattern will draw |
| * |
| * @exception IllegalArgumentException <ul> |
| * <li>ERROR_NULL_ARGUMENT - if the device is null and there is no current device, or the image is null</li> |
| * <li>ERROR_INVALID_ARGUMENT - if the image has been disposed</li> |
| * </ul> |
| * @exception SWTException <ul> |
| * <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li> |
| * </ul> |
| * @exception SWTError <ul> |
| * <li>ERROR_NO_HANDLES if a handle for the pattern could not be obtained</li> |
| * </ul> |
| * |
| * @see #dispose() |
| */ |
| public Pattern(Device device, Image image) { |
| super(device); |
| if (image == null) SWT.error(SWT.ERROR_NULL_ARGUMENT); |
| if (image.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT); |
| image.createSurface(); |
| handle = Cairo.cairo_pattern_create_for_surface(image.surface); |
| if (handle == 0) SWT.error(SWT.ERROR_NO_HANDLES); |
| Cairo.cairo_pattern_set_extend(handle, Cairo.CAIRO_EXTEND_REPEAT); |
| surface = image.surface; |
| init(); |
| } |
| |
| /** |
| * Constructs a new Pattern that represents a linear, two color |
| * gradient. Drawing with the pattern will cause the resulting area to be |
| * tiled with the gradient specified by the arguments. |
| * <p> |
| * This operation requires the operating system's advanced |
| * graphics subsystem which may not be available on some |
| * platforms. |
| * </p> |
| * <p> |
| * You must dispose the pattern when it is no longer required. |
| * </p> |
| * |
| * @param device the device on which to allocate the pattern |
| * @param x1 the x coordinate of the starting corner of the gradient |
| * @param y1 the y coordinate of the starting corner of the gradient |
| * @param x2 the x coordinate of the ending corner of the gradient |
| * @param y2 the y coordinate of the ending corner of the gradient |
| * @param color1 the starting color of the gradient |
| * @param color2 the ending color of the gradient |
| * |
| * @exception IllegalArgumentException <ul> |
| * <li>ERROR_NULL_ARGUMENT - if the device is null and there is no current device, |
| * or if either color1 or color2 is null</li> |
| * <li>ERROR_INVALID_ARGUMENT - if either color1 or color2 has been disposed</li> |
| * </ul> |
| * @exception SWTException <ul> |
| * <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li> |
| * </ul> |
| * @exception SWTError <ul> |
| * <li>ERROR_NO_HANDLES if a handle for the pattern could not be obtained</li> |
| * </ul> |
| * |
| * @see #dispose() |
| */ |
| public Pattern(Device device, float x1, float y1, float x2, float y2, Color color1, Color color2) { |
| this(device, x1, y1, x2, y2, color1, 0xFF, color2, 0xFF); |
| } |
| /** |
| * Constructs a new Pattern that represents a linear, two color |
| * gradient. Drawing with the pattern will cause the resulting area to be |
| * tiled with the gradient specified by the arguments. |
| * <p> |
| * This operation requires the operating system's advanced |
| * graphics subsystem which may not be available on some |
| * platforms. |
| * </p> |
| * <p> |
| * You must dispose the pattern when it is no longer required. |
| * </p> |
| * |
| * @param device the device on which to allocate the pattern |
| * @param x1 the x coordinate of the starting corner of the gradient |
| * @param y1 the y coordinate of the starting corner of the gradient |
| * @param x2 the x coordinate of the ending corner of the gradient |
| * @param y2 the y coordinate of the ending corner of the gradient |
| * @param color1 the starting color of the gradient |
| * @param alpha1 the starting alpha value of the gradient |
| * @param color2 the ending color of the gradient |
| * @param alpha2 the ending alpha value of the gradient |
| * |
| * @exception IllegalArgumentException <ul> |
| * <li>ERROR_NULL_ARGUMENT - if the device is null and there is no current device, |
| * or if either color1 or color2 is null</li> |
| * <li>ERROR_INVALID_ARGUMENT - if either color1 or color2 has been disposed</li> |
| * </ul> |
| * @exception SWTException <ul> |
| * <li>ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available</li> |
| * </ul> |
| * @exception SWTError <ul> |
| * <li>ERROR_NO_HANDLES if a handle for the pattern could not be obtained</li> |
| * </ul> |
| * |
| * @see #dispose() |
| * |
| * @since 3.2 |
| */ |
| public Pattern(Device device, float x1, float y1, float x2, float y2, Color color1, int alpha1, Color color2, int alpha2) { |
| super(device); |
| x1 = DPIUtil.autoScaleUp(x1); |
| y1 = DPIUtil.autoScaleUp(y1); |
| x2 = DPIUtil.autoScaleUp(x2); |
| y2 = DPIUtil.autoScaleUp(y2); |
| if (color1 == null) SWT.error(SWT.ERROR_NULL_ARGUMENT); |
| if (color1.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT); |
| if (color2 == null) SWT.error(SWT.ERROR_NULL_ARGUMENT); |
| if (color2.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT); |
| handle = Cairo.cairo_pattern_create_linear(x1, y1, x2, y2); |
| if (handle == 0) SWT.error(SWT.ERROR_NO_HANDLES); |
| GC.setCairoPatternColor(handle, 0, color1, alpha1); |
| GC.setCairoPatternColor(handle, 1, color2, alpha2); |
| Cairo.cairo_pattern_set_extend(handle, Cairo.CAIRO_EXTEND_REPEAT); |
| init(); |
| } |
| |
| @Override |
| void destroy() { |
| Cairo.cairo_pattern_destroy(handle); |
| handle = surface = 0; |
| } |
| |
| /** |
| * Returns <code>true</code> if the Pattern has been disposed, |
| * and <code>false</code> otherwise. |
| * <p> |
| * This method gets the dispose state for the Pattern. |
| * When a Pattern has been disposed, it is an error to |
| * invoke any other method (except {@link #dispose()}) using the Pattern. |
| * |
| * @return <code>true</code> when the Pattern is disposed, and <code>false</code> otherwise |
| */ |
| @Override |
| public boolean isDisposed() { |
| return handle == 0; |
| } |
| |
| /** |
| * Returns a string containing a concise, human-readable |
| * description of the receiver. |
| * |
| * @return a string representation of the receiver |
| */ |
| @Override |
| public String toString() { |
| if (isDisposed()) return "Pattern {*DISPOSED*}"; |
| return "Pattern {" + handle + "}"; |
| } |
| |
| } |