From f2e8d919f0c026e1ce81e54fd612368f088999a1 Mon Sep 17 00:00:00 2001
From: Zoltan Ujhelyi <ujhelyiz@mit.bme.hu>
Date: Thu, 9 Feb 2012 23:22:39 +0100
Subject: [PATCH] Initial support for multitouch zoom

---
 .../org/eclipse/zest/core/widgets/Graph.java  | 27 +++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/org.eclipse.zest.core/src/org/eclipse/zest/core/widgets/Graph.java b/org.eclipse.zest.core/src/org/eclipse/zest/core/widgets/Graph.java
index 2189a78f7..60d4f34dd 100644
--- a/org.eclipse.zest.core/src/org/eclipse/zest/core/widgets/Graph.java
+++ b/org.eclipse.zest.core/src/org/eclipse/zest/core/widgets/Graph.java
@@ -39,6 +39,8 @@
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.events.ControlEvent;
 import org.eclipse.swt.events.ControlListener;
+import org.eclipse.swt.events.GestureEvent;
+import org.eclipse.swt.events.GestureListener;
 import org.eclipse.swt.events.PaintEvent;
 import org.eclipse.swt.events.PaintListener;
 import org.eclipse.swt.events.SelectionAdapter;
@@ -61,6 +63,8 @@
  */
 public class Graph extends FigureCanvas implements IContainer {
 
+	private static final double MINIMUM_ZOOM = 0.1;
+	private static final double MAXIMUM_ZOOM = 10.0;
 	// CLASS CONSTANTS
 	public static final int ANIMATION_TIME = 500;
 	public static final int FISHEYE_ANIMATION_TIME = 100;
@@ -197,6 +201,29 @@ public void controlMoved(ControlEvent e) {
 				// do nothing
 			}
 		});
+		this.addGestureListener(new GestureListener() {
+
+			double zoom = 1.0;
+
+			public void gesture(GestureEvent e) {
+				switch (e.detail) {
+				case SWT.GESTURE_BEGIN:
+					zoom = getRootLayer().getScale();
+					break;
+				case SWT.GESTURE_END:
+					break;
+				case SWT.GESTURE_MAGNIFY:
+					double newValue = zoom * e.magnification;
+					if (newValue >= MINIMUM_ZOOM && newValue <= MAXIMUM_ZOOM) {
+						getRootLayer().setScale(newValue);
+						getRootLayer().repaint();
+					}
+					break;
+				default:
+					// Do nothing
+				}
+			}
+		});
 	}
 
 	/**