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Viewing changes to src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Project/Services/ClickOrDragMouseGesture.cs

  • Committer: sk
  • Date: 2011-09-10 05:17:57 UTC
  • Revision ID: halega@halega.com-20110910051757-qfouz1llya9m6boy
4.1.0.7915 Release Candidate 1

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src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Project/Services/ClickOrDragMouseGesture.cs
 
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// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
 
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// This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
 
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using System;
 
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using System.Diagnostics;
 
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using System.Windows;
 
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using System.Windows.Input;
 
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namespace ICSharpCode.WpfDesign.Designer.Services
 
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{
 
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        /// <summary>
 
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        /// Base class for mouse gestures that should start dragging only after a minimum drag distance.
 
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        /// </summary>
 
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        abstract class ClickOrDragMouseGesture : MouseGestureBase
 
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        {
 
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                protected Point startPoint;
 
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                protected bool hasDragStarted;
 
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                protected IInputElement positionRelativeTo;
 
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                const double MinimumDragDistance = 3;
 
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                protected sealed override void OnStarted(MouseButtonEventArgs e)
 
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                {
 
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                        Debug.Assert(positionRelativeTo != null);
 
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                        hasDragStarted = false;
 
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                        startPoint = e.GetPosition(positionRelativeTo);
 
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                }
 
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                protected override void OnMouseMove(object sender, MouseEventArgs e)
 
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                {
 
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                        if (!hasDragStarted) {
 
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                                Vector v = e.GetPosition(positionRelativeTo) - startPoint;
 
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                                if (Math.Abs(v.X) >= SystemParameters.MinimumHorizontalDragDistance
 
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                                    || Math.Abs(v.Y) >= SystemParameters.MinimumVerticalDragDistance) {
 
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                                        hasDragStarted = true;
 
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                                        OnDragStarted(e);
 
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                                }
 
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                        }
 
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                }
 
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                protected override void OnStopped()
 
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                {
 
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                        hasDragStarted = false;
 
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                }
 
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                protected virtual void OnDragStarted(MouseEventArgs e) {}
 
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        }
 
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}