bundles/org.simantics.g2d/src/org/simantics/g2d/utils/CanvasUtils.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.utils;
  13
  14 import java.util.function.Supplier;
  15
  16 import org.simantics.g2d.canvas.Hints;
  17 import org.simantics.g2d.canvas.ICanvasContext;
  18 import org.simantics.g2d.diagram.DiagramHints;
  19 import org.simantics.g2d.diagram.IDiagram;
  20 import org.simantics.scenegraph.g2d.events.command.Command;
  21 import org.simantics.scenegraph.g2d.events.command.CommandEvent;
  22 import org.simantics.scenegraph.g2d.events.command.Commands;
  23 import org.simantics.utils.threads.IThreadWorkQueue;
  24 import org.simantics.utils.threads.ThreadUtils;
  25
  26 /**
  27  * @author Toni Kalajainen
  28  * @author Tuukka Lehtonen
  29  */
  30 public class CanvasUtils {
  31
  32     /**
  33      * Enqueue a command in the event queue of the specified canvas context.
  34      *
  35      * @param ctx queue context
  36      * @param commandId ID of the command to queue
  37      *
  38      * @see #sendCommand(ICanvasContext, Command)
  39      */
  40     public static void sendCommand(ICanvasContext ctx, String commandId)
  41     {
  42         sendCommand(ctx, new Command(commandId));
  43     }
  44
  45     /**
  46      * Enqueue a command in the event queue of the specified canvas context.
  47      *
  48      * @param ctx queue context
  49      * @param cmd the command to queue
  50      */
  51     public static void sendCommand(ICanvasContext ctx, Command cmd)
  52     {
  53         CommandEvent e = new CommandEvent(ctx, System.currentTimeMillis(), cmd);
  54         ctx.getEventQueue().queueEvent(e);
  55     }
  56
  57     /**
  58      * A utility for scheduling a zoom-to-fit operation when an Eclipse
  59      * workbench editor is initially opened.
  60      *
  61      * <p>
  62      * There are two asynchronous calls, first into the workbench (SWT) UI
  63      * thread and then into the canvas context thread. This will guarantee that
  64      * the parenting SWT control has been resized to its actual size instead of
  65      * the initial (0,0) size which widgets start out at. In order to perform a
  66      * zoom-to-fit operation we simply have to know the bounds of the parenting
  67      * control. Thus, we need to ensure that this information is available and
  68      * correct.
  69      *
  70      * @param swtThread
  71      * @param disposed
  72      * @param canvasContext
  73      * @param diagramToFit
  74      */
  75     public static void scheduleZoomToFit(IThreadWorkQueue swtThread, final Supplier<Boolean> disposed,
  76             final ICanvasContext canvasContext, final IDiagram diagramToFit)
  77     {
  78         scheduleZoomToFit(swtThread, disposed, canvasContext, diagramToFit, true);
  79     }
  80
  81     /**
  82      * A utility for scheduling a zoom-to-fit operation when an Eclipse
  83      * workbench editor is initially opened.
  84      *
  85      * <p>
  86      * There are two asynchronous calls, first into the workbench (SWT) UI
  87      * thread and then into the canvas context thread. This will guarantee that
  88      * the parenting SWT control has been resized to its actual size instead of
  89      * the initial (0,0) size which widgets start out at. In order to perform a
  90      * zoom-to-fit operation we simply have to know the bounds of the parenting
  91      * control. Thus, we need to ensure that this information is available and
  92      * correct.
  93      *
  94      * @param swtThread
  95      * @param disposed
  96      * @param canvasContext
  97      * @param diagramToFit
  98      * @param zoomToFit
  99      */
 100     public static void scheduleZoomToFit(IThreadWorkQueue swtThread, final Supplier<Boolean> disposed,
 101             final ICanvasContext canvasContext, final IDiagram diagramToFit, boolean zoomToFit)
 102     {
 103         if (diagramToFit == null)
 104             throw new IllegalStateException("source diagram is null");
 105
 106         Boolean canvasZoomToFit = canvasContext.getHintStack().getHint(DiagramHints.KEY_INITIAL_ZOOM_TO_FIT);
 107         diagramToFit.setHint(Hints.KEY_DISABLE_PAINTING, Boolean.TRUE);
 108         if (zoomToFit && !Boolean.FALSE.equals(canvasZoomToFit))
 109             diagramToFit.setHint(DiagramHints.KEY_INITIAL_ZOOM_TO_FIT, Boolean.TRUE);
 110
 111         ThreadUtils.asyncExec(swtThread, new Runnable() {
 112             @Override
 113             public void run() {
 114                 if (disposed.get() || canvasContext.isDisposed())
 115                     return;
 116
 117                 ThreadUtils.asyncExec(canvasContext.getThreadAccess(), new Runnable() {
 118                     @Override
 119                     public void run() {
 120                         if (disposed.get() || canvasContext.isDisposed())
 121                             return;
 122
 123                         Boolean zoomToFit = diagramToFit.removeHint(DiagramHints.KEY_INITIAL_ZOOM_TO_FIT);
 124                         diagramToFit.removeHint(Hints.KEY_DISABLE_PAINTING);
 125
 126                         if (Boolean.TRUE.equals(zoomToFit))
 127                             CanvasUtils.sendCommand(canvasContext, Commands.ZOOM_TO_FIT);
 128                         CanvasUtils.sendCommand(canvasContext, Commands.ENABLE_PAINTING);
 129                     }
 130                 });
 131             }
 132         });
 133     }
 134
 135 }