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1 /*******************************************************************************
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2 * Copyright (c) 2000, 2004 IBM Corporation and others.
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3 * All rights reserved. This program and the accompanying materials
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4 * are made available under the terms of the Eclipse Public License v1.0
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5 * which accompanies this distribution, and is available at
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6 * http://www.eclipse.org/legal/epl-v10.html
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7 *
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8 * Contributors:
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9 * IBM Corporation - initial API and implementation
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10 * D Port:
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11 * Bill Baxter <wbaxter> at gmail com
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12 *******************************************************************************/
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13 module snippets.canvas.Snippet48;
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14
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15 /*
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16 * Canvas example snippet: scroll an image (flicker free, no double buffering)
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17 *
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18 * For a list of all SWT example snippets see
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19 * http://www.eclipse.org/swt/snippets/
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20 */
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21 import dwt.DWT;
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22 import dwt.graphics.GC;
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23 import dwt.graphics.Point;
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24 import dwt.graphics.Rectangle;
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25 import dwt.graphics.Color;
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26 import dwt.graphics.Image;
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27 import dwt.layout.FillLayout;
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28 import dwt.widgets.Display;
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29 import dwt.widgets.Shell;
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30 import dwt.widgets.Event;
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31 import dwt.widgets.Listener;
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32 import dwt.widgets.FileDialog;
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33 import dwt.widgets.Canvas;
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34 import dwt.widgets.ScrollBar;
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35 import dwt.layout.FillLayout;
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36
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37 import dwt.dwthelper.utils;
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38
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39 void main () {
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40 Display display = new Display ();
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41 Shell shell = new Shell (display);
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42 shell.setLayout(new FillLayout());
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43 Image originalImage = null;
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44 FileDialog dialog = new FileDialog (shell, DWT.OPEN);
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45 dialog.setText ("Open an image file or cancel");
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46 String string = dialog.open ();
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47 if (string !is null) {
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48 originalImage = new Image (display, string);
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49 }
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50 if (originalImage is null) {
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51 int width = 150, height = 200;
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52 originalImage = new Image (display, width, height);
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53 GC gc = new GC (originalImage);
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54 gc.fillRectangle (0, 0, width, height);
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55 gc.drawLine (0, 0, width, height);
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56 gc.drawLine (0, height, width, 0);
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57 gc.drawText ("Default Image", 10, 10);
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58 gc.dispose ();
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59 }
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60 final Image image = originalImage;
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61 final Point origin = new Point (0, 0);
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62 final Canvas canvas = new Canvas (shell, DWT.NO_BACKGROUND |
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63 DWT.NO_REDRAW_RESIZE | DWT.V_SCROLL | DWT.H_SCROLL);
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64 final ScrollBar hBar = canvas.getHorizontalBar ();
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65 void onHBarSelection (Event e) {
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66 int hSelection = hBar.getSelection ();
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67 int destX = -hSelection - origin.x;
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68 Rectangle rect = image.getBounds ();
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69 canvas.scroll (destX, 0, 0, 0, rect.width, rect.height, false);
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70 origin.x = -hSelection;
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71 }
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72 final ScrollBar vBar = canvas.getVerticalBar ();
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73 void onVBarSelection(Event e) {
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74 int vSelection = vBar.getSelection ();
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75 int destY = -vSelection - origin.y;
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76 Rectangle rect = image.getBounds ();
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77 canvas.scroll (0, destY, 0, 0, rect.width, rect.height, false);
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78 origin.y = -vSelection;
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79 }
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80 void onResize(Event e) {
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81 Rectangle rect = image.getBounds ();
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82 Rectangle client = canvas.getClientArea ();
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83 hBar.setMaximum (rect.width);
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84 vBar.setMaximum (rect.height);
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85 hBar.setThumb (Math.min (rect.width, client.width));
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86 vBar.setThumb (Math.min (rect.height, client.height));
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87 int hPage = rect.width - client.width;
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88 int vPage = rect.height - client.height;
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89 int hSelection = hBar.getSelection ();
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90 int vSelection = vBar.getSelection ();
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91 if (hSelection >= hPage) {
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92 if (hPage <= 0) hSelection = 0;
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93 origin.x = -hSelection;
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94 }
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95 if (vSelection >= vPage) {
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96 if (vPage <= 0) vSelection = 0;
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97 origin.y = -vSelection;
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98 }
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99 canvas.redraw ();
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100 }
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101 void onPaint (Event e) {
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102 GC gc = e.gc;
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103 gc.drawImage (image, origin.x, origin.y);
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104 Rectangle rect = image.getBounds ();
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105 Rectangle client = canvas.getClientArea ();
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106 int marginWidth = client.width - rect.width;
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107 if (marginWidth > 0) {
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108 gc.fillRectangle (rect.width, 0, marginWidth, client.height);
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109 }
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110 int marginHeight = client.height - rect.height;
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111 if (marginHeight > 0) {
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112 gc.fillRectangle (0, rect.height, client.width, marginHeight);
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113 }
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114 }
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115
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116 hBar.addListener (DWT.Selection, dgListener(&onHBarSelection));
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117 vBar.addListener (DWT.Selection, dgListener(&onVBarSelection));
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118 canvas.addListener (DWT.Resize, dgListener(&onResize));
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119 canvas.addListener (DWT.Paint, dgListener(&onPaint));
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120
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121 shell.setSize (200, 150);
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122 shell.open ();
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123 while (!shell.isDisposed ()) {
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124 if (!display.readAndDispatch ()) display.sleep ();
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125 }
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126 originalImage.dispose();
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127 display.dispose ();
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128 }
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129
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