bundles/org.simantics.g2d/src/org/simantics/g2d/element/handler/impl/AbstractGrabbable.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management
   3  * in Industry THTH ry.
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     VTT Technical Research Centre of Finland - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.g2d.element.handler.impl;
  13
  14 import java.awt.geom.Point2D;
  15 import java.util.HashMap;
  16 import java.util.Map;
  17 import java.util.Map.Entry;
  18
  19 import org.simantics.g2d.canvas.ICanvasContext;
  20 import org.simantics.g2d.canvas.IMouseCaptureHandle;
  21 import org.simantics.g2d.diagram.participant.DiagramParticipant;
  22 import org.simantics.g2d.diagram.participant.ElementInteractor;
  23 import org.simantics.g2d.element.ElementUtils;
  24 import org.simantics.g2d.element.IElement;
  25 import org.simantics.g2d.element.handler.HandleMouseEvent;
  26 import org.simantics.scenegraph.g2d.events.MouseEvent;
  27 import org.simantics.scenegraph.g2d.events.MouseEvent.MouseButtonEvent;
  28 import org.simantics.scenegraph.g2d.events.MouseEvent.MouseButtonPressedEvent;
  29 import org.simantics.scenegraph.g2d.events.MouseEvent.MouseButtonReleasedEvent;
  30 import org.simantics.scenegraph.g2d.events.MouseEvent.MouseClickEvent;
  31 import org.simantics.scenegraph.g2d.events.MouseEvent.MouseDragBegin;
  32 import org.simantics.scenegraph.g2d.events.MouseEvent.MouseMovedEvent;
  33 import org.simantics.utils.datastructures.hints.IHintContext.Key;
  34 import org.simantics.utils.datastructures.hints.IHintContext.MouseSpecificKeyOf;
  35
  36 /**
  37  * Base implementation for handlers that handle grabbable objects.
  38  *
  39  * TODO Esc button cancels grab
  40  *
  41  * @author Toni Kalajainen
  42  */
  43 public abstract class AbstractGrabbable implements HandleMouseEvent {
  44
  45         private static final long serialVersionUID = -3620527648364111724L;
  46         Double strayDistance;
  47         protected int grabMouseButton = MouseEvent.LEFT_BUTTON;
  48
  49         /**
  50          * Create grabbable
  51          * @param strayDistance stray distance or null for no limit
  52          */
  53         public AbstractGrabbable(Double strayDistance)
  54         {
  55                 this.strayDistance = strayDistance;
  56         }
  57
  58         public AbstractGrabbable()
  59         {
  60                 this.strayDistance = 1000.0;
  61         }
  62
  63         @Override
  64         public boolean handleMouseEvent(IElement e, ICanvasContext ctx, MouseEvent me) {
  65                 int     pointerId               = me.mouseId;
  66                 GrabInfo gi                             = getGrabInfo(e, ctx, pointerId);
  67
  68                 if ((me instanceof MouseClickEvent)||(me instanceof MouseDragBegin)) {
  69                         return gi!=null;
  70                 }
  71
  72                 if ((me instanceof MouseMovedEvent)) {
  73                         MouseMovedEvent mme = (MouseMovedEvent) me;
  74                         if (gi==null) return false;
  75
  76                         gi.prevPosCanvas.setLocation( gi.dragPosCanvas );
  77                         gi.prevPosControl.setLocation( gi.dragPosControl );
  78                         gi.prevPosElement.setLocation( gi.dragPosElement );
  79
  80                         // Update drag positions
  81                         gi.dragPosControl.setLocation(me.controlPosition);
  82                         ElementUtils.controlToCanvasCoordinate(ctx, mme.controlPosition, gi.dragPosCanvas);
  83                         ElementUtils.controlToElementCoordinate(e, ctx, mme.controlPosition, gi.dragPosElement);
  84                         // Check if pointer has strayed too far, if so release grab
  85                         double dist = gi.dragPosControl.distance(gi.grabPosControl);
  86
  87                         // Pointer has strayed too far -> release the pointer from the button
  88                         if (dist>strayDistance)
  89                         {
  90                                 releaseGrab(e, ctx, pointerId);
  91                                 onGrabCancel(gi, ctx);
  92                                 return true;
  93                         }
  94
  95                         // Handle event
  96                         onDrag(gi, ctx);
  97                         // Consume event
  98                         return true;
  99                 }
 100
 101                 // Mouse released
 102                 if (me instanceof MouseButtonReleasedEvent)
 103                 {
 104                         MouseButtonEvent mbe = (MouseButtonEvent) me;
 105                         if (mbe.button != grabMouseButton) return false;
 106                         if (gi==null) return false;
 107                         releaseGrab(e, ctx, pointerId);
 108                         onRelease(gi, ctx);
 109                         return true;
 110                 }
 111                 // Mouse pressed
 112                 if (me instanceof MouseButtonPressedEvent)
 113                 {
 114                         MouseButtonEvent mbe = (MouseButtonEvent) me;
 115                         if (mbe.button != grabMouseButton) return false;
 116                         if (!onGrabCheck(e, ctx, pointerId, me.controlPosition))
 117                                 return false;
 118                         gi = grabMouse(e, ctx, pointerId, me.controlPosition);
 119                         onGrab(gi,ctx);
 120                         return true;
 121                 }
 122
 123                 return false;
 124         }
 125
 126         /**
 127          * Checks whether grab accepted
 128          * @param e element
 129          * @param pickPos pick position in element coordinates
 130          * @return true if position is grabbable
 131          */
 132         protected abstract boolean onGrabCheck(IElement e, ICanvasContext ctx, int pointerId, Point2D pickPos);
 133
 134         protected abstract void onGrab(GrabInfo gi, ICanvasContext ctx);
 135
 136         /**
 137          * Event when grab is released (and not canceled)
 138          * Invoked after grab is released.
 139          * @param gi
 140          * @param ctx
 141          */
 142         protected abstract void onRelease(GrabInfo gi, ICanvasContext ctx);
 143
 144         protected abstract void onDrag(GrabInfo gi, ICanvasContext ctx);
 145
 146         /**
 147          * Event notified when grab is canceled. Canceling occurs automatically
 148          * when mouse strays too far and when user sends cancel command (presses esc)
 149          *
 150          * @param e
 151          * @param grabPos
 152          */
 153         protected abstract void onGrabCancel(GrabInfo gi, ICanvasContext ctx);
 154
 155         protected void cancelGrab() {
 156         }
 157
 158         public static class GrabInfo {
 159                 // Grabbed element
 160                 public IElement e;
 161                 // grabbing pointer
 162                 public int pointerId;
 163                 // Grab position
 164                 public Point2D grabPosControl = new Point2D.Double();
 165                 public Point2D grabPosCanvas = new Point2D.Double();
 166                 public Point2D grabPosElement = new Point2D.Double();
 167                 // Drag position
 168                 public Point2D dragPosControl = new Point2D.Double();
 169                 public Point2D dragPosCanvas  = new Point2D.Double();
 170                 public Point2D dragPosElement = new Point2D.Double();
 171                 // Prev position
 172                 public Point2D prevPosControl = new Point2D.Double();
 173                 public Point2D prevPosCanvas  = new Point2D.Double();
 174                 public Point2D prevPosElement = new Point2D.Double();
 175                 // Capture handle
 176                 private IMouseCaptureHandle hnd;
 177         }
 178
 179         /**
 180          * Remove GrabInfo object
 181          * @param e
 182          * @param ctx
 183          * @param pointerId
 184          */
 185         private void removeGrabInfo(IElement e, ICanvasContext ctx, int pointerId)
 186         {
 187                 DiagramParticipant dp = ctx.getSingleItem(DiagramParticipant.class);
 188                 Key key = new MouseSpecificKeyOf(pointerId, GrabInfo.class);
 189                 dp.removeElementHint(e, key);
 190         }
 191
 192         /**
 193          * Set GrabInfo object
 194          * @param e
 195          * @param ctx
 196          * @param pointerId
 197          * @param gi
 198          */
 199         private void setGrabInfo(IElement e, ICanvasContext ctx, int pointerId, GrabInfo gi)
 200         {
 201                 DiagramParticipant dp = ctx.getSingleItem(DiagramParticipant.class);
 202                 Key key = new MouseSpecificKeyOf(pointerId, GrabInfo.class);
 203                 dp.setElementHint(e, key, gi);
 204
 205         }
 206
 207         /**
 208          * Get GrabInfo Object
 209          * @param e
 210          * @param ctx
 211          * @param pointerId
 212          * @return
 213          */
 214         private GrabInfo getGrabInfo(IElement e, ICanvasContext ctx, int pointerId)
 215         {
 216                 DiagramParticipant dp = ctx.getSingleItem(DiagramParticipant.class);
 217                 Key key = new MouseSpecificKeyOf(pointerId, GrabInfo.class);
 218                 return dp.getElementHint(e, key);
 219         }
 220
 221         /**
 222          * Get all pointer grabs
 223          * @return
 224          */
 225         protected Map<Integer, GrabInfo> getGrabs(IElement e, ICanvasContext ctx)
 226         {
 227                 DiagramParticipant dp = ctx.getSingleItem(DiagramParticipant.class);
 228                 Map<Key, Object> map = dp.getElementHints(e);
 229                 if (map==null) return null;
 230                 Map<Integer, GrabInfo> result = new HashMap<Integer, GrabInfo>();
 231                 for (Entry<Key, Object> entry : map.entrySet())
 232                 {
 233                         if (!(entry.getValue() instanceof GrabInfo)) continue;
 234                         GrabInfo gi = (GrabInfo) entry.getValue();
 235                         result.put(gi.pointerId, gi);
 236                 }
 237                 return result;
 238         }
 239
 240         protected int getGrabCount(IElement e, ICanvasContext ctx)
 241         {
 242                 DiagramParticipant dp = ctx.getSingleItem(DiagramParticipant.class);
 243                 Map<Key, Object> map = dp.getElementHints(e);
 244                 if (map==null) return 0;
 245                 int result = 0;
 246                 for (Entry<Key, Object> entry : map.entrySet())
 247                 {
 248                         if (!(entry.getValue() instanceof GrabInfo)) continue;
 249                         result ++;
 250                 }
 251                 return result;
 252         }
 253
 254         /**
 255          * Release grab of a pointer
 256          * @param e
 257          * @param ctx
 258          * @param pointerId
 259          */
 260         protected void releaseGrab(IElement e, ICanvasContext ctx, int pointerId)
 261         {
 262                 GrabInfo gi = getGrabInfo(e, ctx, pointerId);
 263                 if (gi==null) return;
 264                 gi.hnd.release();
 265                 removeGrabInfo(e, ctx, pointerId);
 266         }
 267
 268         /**
 269          * Grab a pointer
 270          * @param e
 271          * @param ctx
 272          * @param pointerId
 273          * @param grabPointControl
 274          * @return
 275          */
 276         private GrabInfo grabMouse(IElement e, ICanvasContext ctx, int pointerId, Point2D grabPointControl)
 277         {
 278                 // Release previous capture, if exists
 279                 releaseGrab(e, ctx, pointerId);
 280
 281                 ElementInteractor ei = ctx.getSingleItem(ElementInteractor.class);
 282                 IMouseCaptureHandle hnd = ei.captureMouse(e, pointerId);
 283                 if (hnd == null) return null;
 284
 285                 Point2D grabPointCanvas = ElementUtils.controlToCanvasCoordinate(ctx, grabPointControl, new Point2D.Double());
 286                 Point2D grabPointElement = ElementUtils.controlToElementCoordinate(e, ctx, grabPointControl, new Point2D.Double());
 287
 288                 GrabInfo gi = new GrabInfo();
 289                 gi.e = e;
 290                 gi.hnd = hnd;
 291                 gi.pointerId = pointerId;
 292                 gi.grabPosControl.setLocation(grabPointControl);
 293                 gi.grabPosCanvas.setLocation(grabPointCanvas);
 294                 gi.grabPosElement.setLocation(grabPointElement);
 295
 296                 gi.dragPosControl.setLocation(grabPointControl);
 297                 gi.dragPosCanvas.setLocation(grabPointCanvas);
 298                 gi.dragPosElement.setLocation(grabPointElement);
 299
 300                 gi.prevPosControl.setLocation(grabPointControl);
 301                 gi.prevPosCanvas.setLocation(grabPointCanvas);
 302                 gi.prevPosElement.setLocation(grabPointElement);
 303
 304                 setGrabInfo(e, ctx, pointerId, gi);
 305
 306                 return gi;
 307         }
 308
 309 }