bundles/org.simantics.utils.ui/src/org/simantics/utils/ui/color/ColorGradientCanvas.java

   1 /*******************************************************************************\r
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
   3  * in Industry THTH ry.\r
   4  * All rights reserved. This program and the accompanying materials\r
   5  * are made available under the terms of the Eclipse Public License v1.0\r
   6  * which accompanies this distribution, and is available at\r
   7  * http://www.eclipse.org/legal/epl-v10.html\r
   8  *\r
   9  * Contributors:\r
  10  *     VTT Technical Research Centre of Finland - initial API and implementation\r
  11  *******************************************************************************/\r
  12 package org.simantics.utils.ui.color;\r
  13 \r
  14 import org.eclipse.swt.SWT;\r
  15 import org.eclipse.swt.events.PaintEvent;\r
  16 import org.eclipse.swt.events.PaintListener;\r
  17 import org.eclipse.swt.graphics.GC;\r
  18 import org.eclipse.swt.graphics.Image;\r
  19 import org.eclipse.swt.graphics.Rectangle;\r
  20 import org.eclipse.swt.widgets.Canvas;\r
  21 import org.eclipse.swt.widgets.Composite;\r
  22 import org.eclipse.swt.widgets.Display;\r
  23 \r
  24 /**\r
  25  * \r
  26  * Canvas that shows color gradients\r
  27  * \r
  28  * @author Marko Luukkainen\r
  29  *\r
  30  */\r
  31 public class ColorGradientCanvas extends Canvas{\r
  32         ColorGradient gradient;\r
  33         int style;\r
  34         \r
  35         public ColorGradientCanvas(Composite parent, int style) {\r
  36                 super(parent,(style|SWT.BORDER)&(~(SWT.VERTICAL|SWT.HORIZONTAL)));\r
  37                 this.style = style & (SWT.VERTICAL | SWT.HORIZONTAL) ;\r
  38                 addPaintListener(createPaintListener());\r
  39         }\r
  40         \r
  41         public void setGradient(ColorGradient gradient) {\r
  42                 this.gradient = gradient;\r
  43                 this.redraw();\r
  44         }       \r
  45         \r
  46         protected PaintListener createPaintListener() {\r
  47                 return new PaintListener() {\r
  48                 public void paintControl(PaintEvent e) {\r
  49                         GC gc = e.gc;\r
  50                         Rectangle clip = gc.getClipping();\r
  51                         paintGradient(gc, clip);\r
  52                 }\r
  53             };\r
  54         }\r
  55         \r
  56         protected void paintGradient(GC gc, Rectangle clip) {\r
  57                 if (gradient != null) {\r
  58                         Image image = gradient.getGradientImage(clip.width,clip.height,ColorGradientCanvas.this.style);\r
  59                         gc.drawImage(image, 0, 0);\r
  60                         image.dispose();                \r
  61                 } else {\r
  62                         gc.setBackground(Display.getCurrent().getSystemColor(SWT.COLOR_WHITE));\r
  63                         gc.fillRectangle(clip);\r
  64                 }\r
  65         }\r
  66 \r
  67 }\r