| package org.eclipse.swt.widgets;
|
|
|
| /*
|
| * Copyright (c) 2000, 2002 IBM Corp. All rights reserved. |
| * This file is made available under the terms of the Common Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/cpl-v10.html
|
| */
|
|
|
| import org.eclipse.swt.*;
|
| import org.eclipse.swt.internal.photon.*;
|
| import org.eclipse.swt.graphics.*;
|
|
|
| /** |
| * Instances of this class provide a surface for drawing |
| * arbitrary graphics. |
| * <dl> |
| * <dt><b>Styles:</b></dt> |
| * <dd>(none)</dd> |
| * <dt><b>Events:</b></dt> |
| * <dd>(none)</dd> |
| * </dl> |
| * <p> |
| * This class may be subclassed by custom control implementors |
| * who are building controls that are <em>not</em> constructed |
| * from aggregates of other controls. That is, they are either |
| * painted using SWT graphics calls or are handled by native |
| * methods. |
| * </p> |
| * |
| * @see Composite |
| */ |
| public class Canvas extends Composite {
|
| Caret caret;
|
|
|
| Canvas () {
|
| /* Do nothing */
|
| }
|
|
|
| /** |
| * Constructs a new instance of this class given its parent |
| * and a style value describing its behavior and appearance. |
| * <p> |
| * The style value is either one of the style constants defined in |
| * class <code>SWT</code> which is applicable to instances of this |
| * class, or must be built by <em>bitwise OR</em>'ing together |
| * (that is, using the <code>int</code> "|" operator) two or more |
| * of those <code>SWT</code> style constants. The class description |
| * lists the style constants that are applicable to the class. |
| * Style bits are also inherited from superclasses. |
| * </p> |
| * |
| * @param parent a composite control which will be the parent of the new instance (cannot be null) |
| * @param style the style of control to construct |
| * |
| * @exception IllegalArgumentException <ul> |
| * <li>ERROR_NULL_ARGUMENT - if the parent is null</li> |
| * </ul> |
| * @exception SWTException <ul> |
| * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li> |
| * <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li> |
| * </ul> |
| * |
| * @see SWT |
| * @see Widget#checkSubclass |
| * @see Widget#getStyle |
| */ |
| public Canvas (Composite parent, int style) {
|
| super (parent, style);
|
| }
|
|
|
| /** |
| * Returns the caret. |
| * <p> |
| * The caret for the control is automatically hidden |
| * and shown when the control is painted or resized, |
| * when focus is gained or lost and when an the control |
| * is scrolled. To avoid drawing on top of the caret, |
| * the programmer must hide and show the caret when |
| * drawing in the window any other time. |
| * </p> |
| * |
| * @return the caret |
| * |
| * @exception SWTException <ul> |
| * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> |
| * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> |
| * </ul> |
| */ |
| public Caret getCaret () {
|
| checkWidget();
|
| return caret;
|
| }
|
|
|
| int processFocusIn (int info) {
|
| int result = super.processFocusIn (info);
|
| if (caret != null) caret.setFocus ();
|
| return result;
|
| }
|
| int processFocusOut (int info) {
|
| int result = super.processFocusOut (info);
|
| if (caret != null) caret.killFocus ();
|
| return result;
|
| }
|
|
|
| int processPaint (int callData) {
|
| boolean isVisible = caret != null && caret.isVisible ();
|
| if (isVisible) caret.hideCaret ();
|
| int result = super.processPaint (callData);
|
| if (isVisible) caret.showCaret ();
|
| return result;
|
| }
|
|
|
| public void redraw () {
|
| checkWidget();
|
| boolean isVisible = caret != null && caret.isVisible ();
|
| if (isVisible) caret.hideCaret ();
|
| super.redraw ();
|
| if (isVisible) caret.showCaret ();
|
| }
|
|
|
| public void redraw (int x, int y, int width, int height, boolean all) {
|
| checkWidget();
|
| boolean isVisible = caret != null && caret.isVisible ();
|
| if (isVisible) caret.hideCaret ();
|
| super.redraw (x, y, width, height, all);
|
| if (isVisible) caret.showCaret ();
|
| }
|
|
|
| void releaseWidget () {
|
| if (caret != null) {
|
| caret.releaseWidget ();
|
| caret.releaseHandle ();
|
| }
|
| caret = null;
|
| super.releaseWidget();
|
| }
|
|
|
| /** |
| * Scrolls a rectangular area of the receiver by first copying |
| * the source area to the destination and then causing the area |
| * of the source which is not covered by the destination to |
| * be repainted. Children that intersect the rectangle are |
| * optionally moved during the operation. In addition, outstanding |
| * paint events are flushed before the source area is copied to |
| * ensure that the contents of the canvas are drawn correctly. |
| * |
| * @param destX the x coordinate of the destination |
| * @param destY the y coordinate of the destination |
| * @param x the x coordinate of the source |
| * @param y the y coordinate of the source |
| * @param width the width of the area |
| * @param height the height of the area |
| * @param all <code>true</code>if children should be scrolled, and <code>false</code> otherwise |
| * |
| * @exception SWTException <ul> |
| * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> |
| * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> |
| * </ul> |
| */ |
| public void scroll (int destX, int destY, int x, int y, int width, int height, boolean all) {
|
| checkWidget();
|
| if (width <= 0 || height <= 0) return;
|
| int deltaX = destX - x, deltaY = destY - y;
|
| if (deltaX == 0 && deltaY == 0) return;
|
| if (!isVisible ()) return;
|
| boolean isVisible = caret != null && caret.isVisible ();
|
| if (isVisible) caret.hideCaret ();
|
| GC gc = new GC (this);
|
| gc.copyArea (x, y, width, height, destX, destY);
|
| gc.dispose ();
|
| if (isVisible) caret.showCaret ();
|
| }
|
|
|
| boolean setBounds (int x, int y, int width, int height, boolean move, boolean resize) {
|
| checkWidget();
|
| boolean isVisible = (caret != null) && (caret.isVisible ());
|
| if (isVisible) caret.hideCaret ();
|
| boolean changed = super.setBounds (x, y, width, height, move, resize);
|
| if (isVisible) caret.showCaret ();
|
| return changed;
|
| }
|
|
|
| /** |
| * Sets the receiver's caret. |
| * <p> |
| * The caret for the control is automatically hidden |
| * and shown when the control is painted or resized, |
| * when focus is gained or lost and when an the control |
| * is scrolled. To avoid drawing on top of the caret, |
| * the programmer must hide and show the caret when |
| * drawing in the window any other time. |
| * </p> |
| * @param caret the new caret for the receiver, may be null |
| * |
| * @exception IllegalArgumentException <ul> |
| * <li>ERROR_INVALID_ARGUMENT - if the caret has been disposed</li> |
| * </ul> |
| * @exception SWTException <ul> |
| * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> |
| * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> |
| * </ul> |
| */ |
| public void setCaret (Caret caret) {
|
| checkWidget();
|
| Caret newCaret = caret;
|
| Caret oldCaret = this.caret;
|
| this.caret = newCaret;
|
| if (isFocusControl ()) {
|
| if (oldCaret != null) oldCaret.killFocus ();
|
| if (newCaret != null) {
|
| if (newCaret.isDisposed()) error(SWT.ERROR_INVALID_ARGUMENT);
|
| newCaret.setFocus ();
|
| }
|
| }
|
| }
|
|
|
| }
|