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liufei
864
Util/ListViewDragDropManager.cs
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864
Util/ListViewDragDropManager.cs
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// Copyright (C) Josh Smith - January 2007
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using System;
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using System.Collections.ObjectModel;
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using System.ComponentModel;
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using System.Diagnostics;
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using System.Windows;
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using System.Windows.Controls;
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using System.Windows.Controls.Primitives;
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using System.Windows.Documents;
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using System.Windows.Media;
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using System.Windows.Input;
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using WPF.JoshSmith.Adorners;
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using WPF.JoshSmith.Controls.Utilities;
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namespace WPF.JoshSmith.ServiceProviders.UI
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{
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#region ListViewDragDropManager
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/// <summary>
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/// Manages the dragging and dropping of ListViewItems in a ListView.
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/// The ItemType type parameter indicates the type of the objects in
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/// the ListView's items source. The ListView's ItemsSource must be
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/// set to an instance of ObservableCollection of ItemType, or an
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/// Exception will be thrown.
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/// </summary>
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/// <typeparam name="ItemType">The type of the ListView's items.</typeparam>
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public class ListViewDragDropManager<ItemType> where ItemType : class
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{
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#region Data
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bool canInitiateDrag;
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DragAdorner dragAdorner;
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double dragAdornerOpacity;
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int indexToSelect;
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bool isDragInProgress;
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ItemType itemUnderDragCursor;
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ListView listView;
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Point ptMouseDown;
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bool showDragAdorner;
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#endregion // Data
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#region Constructors
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/// <summary>
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/// Initializes a new instance of ListViewDragManager.
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/// </summary>
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public ListViewDragDropManager()
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{
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this.canInitiateDrag = false;
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this.dragAdornerOpacity = 0.7;
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this.indexToSelect = -1;
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this.showDragAdorner = true;
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}
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/// <summary>
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/// Initializes a new instance of ListViewDragManager.
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/// </summary>
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/// <param name="listView"></param>
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public ListViewDragDropManager( ListView listView )
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: this()
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{
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this.ListView = listView;
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}
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/// <summary>
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/// Initializes a new instance of ListViewDragManager.
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/// </summary>
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/// <param name="listView"></param>
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/// <param name="dragAdornerOpacity"></param>
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public ListViewDragDropManager( ListView listView, double dragAdornerOpacity )
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: this( listView )
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{
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this.DragAdornerOpacity = dragAdornerOpacity;
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}
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/// <summary>
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/// Initializes a new instance of ListViewDragManager.
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/// </summary>
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/// <param name="listView"></param>
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/// <param name="showDragAdorner"></param>
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public ListViewDragDropManager( ListView listView, bool showDragAdorner )
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: this( listView )
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{
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this.ShowDragAdorner = showDragAdorner;
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}
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#endregion // Constructors
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#region Public Interface
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#region DragAdornerOpacity
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/// <summary>
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/// Gets/sets the opacity of the drag adorner. This property has no
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/// effect if ShowDragAdorner is false. The default value is 0.7
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/// </summary>
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public double DragAdornerOpacity
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{
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get { return this.dragAdornerOpacity; }
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set
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{
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if( this.IsDragInProgress )
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throw new InvalidOperationException( "Cannot set the DragAdornerOpacity property during a drag operation." );
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if( value < 0.0 || value > 1.0 )
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throw new ArgumentOutOfRangeException( "DragAdornerOpacity", value, "Must be between 0 and 1." );
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this.dragAdornerOpacity = value;
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}
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}
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#endregion // DragAdornerOpacity
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#region IsDragInProgress
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/// <summary>
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/// Returns true if there is currently a drag operation being managed.
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/// </summary>
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public bool IsDragInProgress
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{
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get { return this.isDragInProgress; }
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private set { this.isDragInProgress = value; }
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}
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#endregion // IsDragInProgress
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#region ListView
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/// <summary>
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/// Gets/sets the ListView whose dragging is managed. This property
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/// can be set to null, to prevent drag management from occuring. If
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/// the ListView's AllowDrop property is false, it will be set to true.
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/// </summary>
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public ListView ListView
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{
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get { return listView; }
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set
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{
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if( this.IsDragInProgress )
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throw new InvalidOperationException( "Cannot set the ListView property during a drag operation." );
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if( this.listView != null )
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{
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#region Unhook Events
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this.listView.PreviewMouseLeftButtonDown -= listView_PreviewMouseLeftButtonDown;
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this.listView.PreviewMouseMove -= listView_PreviewMouseMove;
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this.listView.DragOver -= listView_DragOver;
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this.listView.DragLeave -= listView_DragLeave;
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this.listView.DragEnter -= listView_DragEnter;
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this.listView.Drop -= listView_Drop;
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#endregion // Unhook Events
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}
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this.listView = value;
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if( this.listView != null )
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{
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if( !this.listView.AllowDrop )
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this.listView.AllowDrop = true;
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#region Hook Events
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this.listView.PreviewMouseLeftButtonDown += listView_PreviewMouseLeftButtonDown;
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this.listView.PreviewMouseMove += listView_PreviewMouseMove;
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this.listView.DragOver += listView_DragOver;
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this.listView.DragLeave += listView_DragLeave;
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this.listView.DragEnter += listView_DragEnter;
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this.listView.Drop += listView_Drop;
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#endregion // Hook Events
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}
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}
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}
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#endregion // ListView
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#region ProcessDrop [event]
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/// <summary>
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/// Raised when a drop occurs. By default the dropped item will be moved
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/// to the target index. Handle this event if relocating the dropped item
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/// requires custom behavior. Note, if this event is handled the default
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/// item dropping logic will not occur.
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/// </summary>
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public event EventHandler<ProcessDropEventArgs<ItemType>> ProcessDrop;
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#endregion // ProcessDrop [event]
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#region ShowDragAdorner
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/// <summary>
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/// Gets/sets whether a visual representation of the ListViewItem being dragged
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/// follows the mouse cursor during a drag operation. The default value is true.
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/// </summary>
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public bool ShowDragAdorner
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{
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get { return this.showDragAdorner; }
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set
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{
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if( this.IsDragInProgress )
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throw new InvalidOperationException( "Cannot set the ShowDragAdorner property during a drag operation." );
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this.showDragAdorner = value;
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}
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}
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#endregion // ShowDragAdorner
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#endregion // Public Interface
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#region Event Handling Methods
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#region listView_PreviewMouseLeftButtonDown
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void listView_PreviewMouseLeftButtonDown( object sender, MouseButtonEventArgs e )
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{
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if( this.IsMouseOverScrollbar )
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{
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// 4/13/2007 - Set the flag to false when cursor is over scrollbar.
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this.canInitiateDrag = false;
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return;
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}
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int index = this.IndexUnderDragCursor;
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this.canInitiateDrag = index > -1;
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if( this.canInitiateDrag )
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{
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// Remember the location and index of the ListViewItem the user clicked on for later.
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this.ptMouseDown = MouseUtilities.GetMousePosition( this.listView );
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this.indexToSelect = index;
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}
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else
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{
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this.ptMouseDown = new Point( -10000, -10000 );
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this.indexToSelect = -1;
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}
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}
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#endregion // listView_PreviewMouseLeftButtonDown
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#region listView_PreviewMouseMove
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void listView_PreviewMouseMove( object sender, MouseEventArgs e )
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{
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if( !this.CanStartDragOperation )
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return;
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// Select the item the user clicked on.
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if( this.listView.SelectedIndex != this.indexToSelect )
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this.listView.SelectedIndex = this.indexToSelect;
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// If the item at the selected index is null, there's nothing
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// we can do, so just return;
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if( this.listView.SelectedItem == null )
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return;
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ListViewItem itemToDrag = this.GetListViewItem( this.listView.SelectedIndex );
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if( itemToDrag == null )
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return;
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AdornerLayer adornerLayer = this.ShowDragAdornerResolved ? this.InitializeAdornerLayer( itemToDrag ) : null;
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this.InitializeDragOperation( itemToDrag );
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this.PerformDragOperation();
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this.FinishDragOperation( itemToDrag, adornerLayer );
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}
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#endregion // listView_PreviewMouseMove
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#region listView_DragOver
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void listView_DragOver( object sender, DragEventArgs e )
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{
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e.Effects = DragDropEffects.Move;
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if( this.ShowDragAdornerResolved )
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this.UpdateDragAdornerLocation();
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// Update the item which is known to be currently under the drag cursor.
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int index = this.IndexUnderDragCursor;
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this.ItemUnderDragCursor = index < 0 ? null : this.ListView.Items[index] as ItemType;
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}
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#endregion // listView_DragOver
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#region listView_DragLeave
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void listView_DragLeave( object sender, DragEventArgs e )
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{
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if( !this.IsMouseOver( this.listView ) )
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{
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if( this.ItemUnderDragCursor != null )
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this.ItemUnderDragCursor = null;
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if( this.dragAdorner != null )
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this.dragAdorner.Visibility = Visibility.Collapsed;
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}
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}
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#endregion // listView_DragLeave
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#region listView_DragEnter
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void listView_DragEnter( object sender, DragEventArgs e )
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{
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if( this.dragAdorner != null && this.dragAdorner.Visibility != Visibility.Visible )
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{
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// Update the location of the adorner and then show it.
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this.UpdateDragAdornerLocation();
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this.dragAdorner.Visibility = Visibility.Visible;
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}
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}
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#endregion // listView_DragEnter
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#region listView_Drop
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void listView_Drop( object sender, DragEventArgs e )
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{
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if( this.ItemUnderDragCursor != null )
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this.ItemUnderDragCursor = null;
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e.Effects = DragDropEffects.None;
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if( !e.Data.GetDataPresent( typeof( ItemType ) ) )
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return;
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// Get the data object which was dropped.
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ItemType data = e.Data.GetData( typeof( ItemType ) ) as ItemType;
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if( data == null )
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return;
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// Get the ObservableCollection<ItemType> which contains the dropped data object.
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ObservableCollection<ItemType> itemsSource = this.listView.ItemsSource as ObservableCollection<ItemType>;
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if( itemsSource == null )
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throw new Exception(
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"A ListView managed by ListViewDragManager must have its ItemsSource set to an ObservableCollection<ItemType>." );
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int oldIndex = itemsSource.IndexOf( data );
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int newIndex = this.IndexUnderDragCursor;
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if( newIndex < 0 )
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{
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// The drag started somewhere else, and our ListView is empty
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// so make the new item the first in the list.
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if( itemsSource.Count == 0 )
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newIndex = 0;
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// The drag started somewhere else, but our ListView has items
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// so make the new item the last in the list.
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else if( oldIndex < 0 )
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newIndex = itemsSource.Count;
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// The user is trying to drop an item from our ListView into
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// our ListView, but the mouse is not over an item, so don't
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// let them drop it.
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else
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return;
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}
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// Dropping an item back onto itself is not considered an actual 'drop'.
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if( oldIndex == newIndex )
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return;
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if( this.ProcessDrop != null )
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{
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// Let the client code process the drop.
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ProcessDropEventArgs<ItemType> args = new ProcessDropEventArgs<ItemType>( itemsSource, data, oldIndex, newIndex, e.AllowedEffects );
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this.ProcessDrop( this, args );
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e.Effects = args.Effects;
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}
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else
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{
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// Move the dragged data object from it's original index to the
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// new index (according to where the mouse cursor is). If it was
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// not previously in the ListBox, then insert the item.
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if( oldIndex > -1 )
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itemsSource.Move( oldIndex, newIndex );
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else
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itemsSource.Insert( newIndex, data );
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// Set the Effects property so that the call to DoDragDrop will return 'Move'.
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e.Effects = DragDropEffects.Move;
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}
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}
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#endregion // listView_Drop
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#endregion // Event Handling Methods
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#region Private Helpers
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#region CanStartDragOperation
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bool CanStartDragOperation
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{
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get
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{
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if( Mouse.LeftButton != MouseButtonState.Pressed )
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return false;
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if( !this.canInitiateDrag )
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return false;
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if( this.indexToSelect == -1 )
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return false;
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if( !this.HasCursorLeftDragThreshold )
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return false;
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return true;
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}
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}
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#endregion // CanStartDragOperation
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#region FinishDragOperation
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void FinishDragOperation( ListViewItem draggedItem, AdornerLayer adornerLayer )
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{
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// Let the ListViewItem know that it is not being dragged anymore.
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ListViewItemDragState.SetIsBeingDragged( draggedItem, false );
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this.IsDragInProgress = false;
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if( this.ItemUnderDragCursor != null )
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this.ItemUnderDragCursor = null;
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// Remove the drag adorner from the adorner layer.
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if( adornerLayer != null )
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{
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adornerLayer.Remove( this.dragAdorner );
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this.dragAdorner = null;
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}
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}
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#endregion // FinishDragOperation
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#region GetListViewItem
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ListViewItem GetListViewItem( int index )
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{
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if( this.listView.ItemContainerGenerator.Status != GeneratorStatus.ContainersGenerated )
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return null;
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return this.listView.ItemContainerGenerator.ContainerFromIndex( index ) as ListViewItem;
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}
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ListViewItem GetListViewItem( ItemType dataItem )
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{
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if( this.listView.ItemContainerGenerator.Status != GeneratorStatus.ContainersGenerated )
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return null;
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return this.listView.ItemContainerGenerator.ContainerFromItem( dataItem ) as ListViewItem;
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}
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#endregion // GetListViewItem
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#region HasCursorLeftDragThreshold
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bool HasCursorLeftDragThreshold
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{
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get
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{
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if( this.indexToSelect < 0 )
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return false;
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ListViewItem item = this.GetListViewItem( this.indexToSelect );
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Rect bounds = VisualTreeHelper.GetDescendantBounds( item );
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Point ptInItem = this.listView.TranslatePoint( this.ptMouseDown, item );
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// In case the cursor is at the very top or bottom of the ListViewItem
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// we want to make the vertical threshold very small so that dragging
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// over an adjacent item does not select it.
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double topOffset = Math.Abs( ptInItem.Y );
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double btmOffset = Math.Abs( bounds.Height - ptInItem.Y );
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double vertOffset = Math.Min( topOffset, btmOffset );
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double width = SystemParameters.MinimumHorizontalDragDistance * 2;
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double height = Math.Min( SystemParameters.MinimumVerticalDragDistance, vertOffset ) * 2;
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Size szThreshold = new Size( width, height );
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Rect rect = new Rect( this.ptMouseDown, szThreshold );
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rect.Offset( szThreshold.Width / -2, szThreshold.Height / -2 );
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Point ptInListView = MouseUtilities.GetMousePosition( this.listView );
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return !rect.Contains( ptInListView );
|
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}
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}
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#endregion // HasCursorLeftDragThreshold
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#region IndexUnderDragCursor
|
||||
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/// <summary>
|
||||
/// Returns the index of the ListViewItem underneath the
|
||||
/// drag cursor, or -1 if the cursor is not over an item.
|
||||
/// </summary>
|
||||
int IndexUnderDragCursor
|
||||
{
|
||||
get
|
||||
{
|
||||
int index = -1;
|
||||
for( int i = 0; i < this.listView.Items.Count; ++i )
|
||||
{
|
||||
ListViewItem item = this.GetListViewItem( i );
|
||||
if( this.IsMouseOver( item ) )
|
||||
{
|
||||
index = i;
|
||||
break;
|
||||
}
|
||||
}
|
||||
return index;
|
||||
}
|
||||
}
|
||||
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||||
#endregion // IndexUnderDragCursor
|
||||
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||||
#region InitializeAdornerLayer
|
||||
|
||||
AdornerLayer InitializeAdornerLayer( ListViewItem itemToDrag )
|
||||
{
|
||||
// Create a brush which will paint the ListViewItem onto
|
||||
// a visual in the adorner layer.
|
||||
VisualBrush brush = new VisualBrush( itemToDrag );
|
||||
|
||||
// Create an element which displays the source item while it is dragged.
|
||||
this.dragAdorner = new DragAdorner( this.listView, itemToDrag.RenderSize, brush );
|
||||
|
||||
// Set the drag adorner's opacity.
|
||||
this.dragAdorner.Opacity = this.DragAdornerOpacity;
|
||||
|
||||
AdornerLayer layer = AdornerLayer.GetAdornerLayer( this.listView );
|
||||
layer.Add( dragAdorner );
|
||||
|
||||
// Save the location of the cursor when the left mouse button was pressed.
|
||||
this.ptMouseDown = MouseUtilities.GetMousePosition( this.listView );
|
||||
|
||||
return layer;
|
||||
}
|
||||
|
||||
#endregion // InitializeAdornerLayer
|
||||
|
||||
#region InitializeDragOperation
|
||||
|
||||
void InitializeDragOperation( ListViewItem itemToDrag )
|
||||
{
|
||||
// Set some flags used during the drag operation.
|
||||
this.IsDragInProgress = true;
|
||||
this.canInitiateDrag = false;
|
||||
|
||||
// Let the ListViewItem know that it is being dragged.
|
||||
ListViewItemDragState.SetIsBeingDragged( itemToDrag, true );
|
||||
}
|
||||
|
||||
#endregion // InitializeDragOperation
|
||||
|
||||
#region IsMouseOver
|
||||
|
||||
bool IsMouseOver( Visual target )
|
||||
{
|
||||
// We need to use MouseUtilities to figure out the cursor
|
||||
// coordinates because, during a drag-drop operation, the WPF
|
||||
// mechanisms for getting the coordinates behave strangely.
|
||||
|
||||
Rect bounds = VisualTreeHelper.GetDescendantBounds( target );
|
||||
Point mousePos = MouseUtilities.GetMousePosition( target );
|
||||
return bounds.Contains( mousePos );
|
||||
}
|
||||
|
||||
#endregion // IsMouseOver
|
||||
|
||||
#region IsMouseOverScrollbar
|
||||
|
||||
/// <summary>
|
||||
/// Returns true if the mouse cursor is over a scrollbar in the ListView.
|
||||
/// </summary>
|
||||
bool IsMouseOverScrollbar
|
||||
{
|
||||
get
|
||||
{
|
||||
Point ptMouse = MouseUtilities.GetMousePosition( this.listView );
|
||||
HitTestResult res = VisualTreeHelper.HitTest( this.listView, ptMouse );
|
||||
if( res == null )
|
||||
return false;
|
||||
|
||||
DependencyObject depObj = res.VisualHit;
|
||||
while( depObj != null )
|
||||
{
|
||||
if( depObj is ScrollBar )
|
||||
return true;
|
||||
|
||||
// VisualTreeHelper works with objects of type Visual or Visual3D.
|
||||
// If the current object is not derived from Visual or Visual3D,
|
||||
// then use the LogicalTreeHelper to find the parent element.
|
||||
if( depObj is Visual || depObj is System.Windows.Media.Media3D.Visual3D )
|
||||
depObj = VisualTreeHelper.GetParent( depObj );
|
||||
else
|
||||
depObj = LogicalTreeHelper.GetParent( depObj );
|
||||
}
|
||||
|
||||
return false;
|
||||
}
|
||||
}
|
||||
|
||||
#endregion // IsMouseOverScrollbar
|
||||
|
||||
#region ItemUnderDragCursor
|
||||
|
||||
ItemType ItemUnderDragCursor
|
||||
{
|
||||
get { return this.itemUnderDragCursor; }
|
||||
set
|
||||
{
|
||||
if( this.itemUnderDragCursor == value )
|
||||
return;
|
||||
|
||||
// The first pass handles the previous item under the cursor.
|
||||
// The second pass handles the new one.
|
||||
for( int i = 0; i < 2; ++i )
|
||||
{
|
||||
if( i == 1 )
|
||||
this.itemUnderDragCursor = value;
|
||||
|
||||
if( this.itemUnderDragCursor != null )
|
||||
{
|
||||
ListViewItem listViewItem = this.GetListViewItem( this.itemUnderDragCursor );
|
||||
if( listViewItem != null )
|
||||
ListViewItemDragState.SetIsUnderDragCursor( listViewItem, i == 1 );
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
#endregion // ItemUnderDragCursor
|
||||
|
||||
#region PerformDragOperation
|
||||
|
||||
void PerformDragOperation()
|
||||
{
|
||||
ItemType selectedItem = this.listView.SelectedItem as ItemType;
|
||||
DragDropEffects allowedEffects = DragDropEffects.Move | DragDropEffects.Move | DragDropEffects.Link;
|
||||
if( DragDrop.DoDragDrop( this.listView, selectedItem, allowedEffects ) != DragDropEffects.None )
|
||||
{
|
||||
// The item was dropped into a new location,
|
||||
// so make it the new selected item.
|
||||
this.listView.SelectedItem = selectedItem;
|
||||
}
|
||||
}
|
||||
|
||||
#endregion // PerformDragOperation
|
||||
|
||||
#region ShowDragAdornerResolved
|
||||
|
||||
bool ShowDragAdornerResolved
|
||||
{
|
||||
get { return this.ShowDragAdorner && this.DragAdornerOpacity > 0.0; }
|
||||
}
|
||||
|
||||
#endregion // ShowDragAdornerResolved
|
||||
|
||||
#region UpdateDragAdornerLocation
|
||||
|
||||
void UpdateDragAdornerLocation()
|
||||
{
|
||||
if( this.dragAdorner != null )
|
||||
{
|
||||
Point ptCursor = MouseUtilities.GetMousePosition( this.ListView );
|
||||
|
||||
double left = ptCursor.X - this.ptMouseDown.X;
|
||||
|
||||
// 4/13/2007 - Made the top offset relative to the item being dragged.
|
||||
ListViewItem itemBeingDragged = this.GetListViewItem( this.indexToSelect );
|
||||
Point itemLoc = itemBeingDragged.TranslatePoint( new Point( 0, 0 ), this.ListView );
|
||||
double top = itemLoc.Y + ptCursor.Y - this.ptMouseDown.Y;
|
||||
|
||||
this.dragAdorner.SetOffsets( left, top );
|
||||
}
|
||||
}
|
||||
|
||||
#endregion // UpdateDragAdornerLocation
|
||||
|
||||
#endregion // Private Helpers
|
||||
}
|
||||
|
||||
#endregion // ListViewDragDropManager
|
||||
|
||||
#region ListViewItemDragState
|
||||
|
||||
/// <summary>
|
||||
/// Exposes attached properties used in conjunction with the ListViewDragDropManager class.
|
||||
/// Those properties can be used to allow triggers to modify the appearance of ListViewItems
|
||||
/// in a ListView during a drag-drop operation.
|
||||
/// </summary>
|
||||
public static class ListViewItemDragState
|
||||
{
|
||||
#region IsBeingDragged
|
||||
|
||||
/// <summary>
|
||||
/// Identifies the ListViewItemDragState's IsBeingDragged attached property.
|
||||
/// This field is read-only.
|
||||
/// </summary>
|
||||
public static readonly DependencyProperty IsBeingDraggedProperty =
|
||||
DependencyProperty.RegisterAttached(
|
||||
"IsBeingDragged",
|
||||
typeof( bool ),
|
||||
typeof( ListViewItemDragState ),
|
||||
new UIPropertyMetadata( false ) );
|
||||
|
||||
/// <summary>
|
||||
/// Returns true if the specified ListViewItem is being dragged, else false.
|
||||
/// </summary>
|
||||
/// <param name="item">The ListViewItem to check.</param>
|
||||
public static bool GetIsBeingDragged( ListViewItem item )
|
||||
{
|
||||
return (bool)item.GetValue( IsBeingDraggedProperty );
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Sets the IsBeingDragged attached property for the specified ListViewItem.
|
||||
/// </summary>
|
||||
/// <param name="item">The ListViewItem to set the property on.</param>
|
||||
/// <param name="value">Pass true if the element is being dragged, else false.</param>
|
||||
internal static void SetIsBeingDragged( ListViewItem item, bool value )
|
||||
{
|
||||
item.SetValue( IsBeingDraggedProperty, value );
|
||||
}
|
||||
|
||||
#endregion // IsBeingDragged
|
||||
|
||||
#region IsUnderDragCursor
|
||||
|
||||
/// <summary>
|
||||
/// Identifies the ListViewItemDragState's IsUnderDragCursor attached property.
|
||||
/// This field is read-only.
|
||||
/// </summary>
|
||||
public static readonly DependencyProperty IsUnderDragCursorProperty =
|
||||
DependencyProperty.RegisterAttached(
|
||||
"IsUnderDragCursor",
|
||||
typeof( bool ),
|
||||
typeof( ListViewItemDragState ),
|
||||
new UIPropertyMetadata( false ) );
|
||||
|
||||
/// <summary>
|
||||
/// Returns true if the specified ListViewItem is currently underneath the cursor
|
||||
/// during a drag-drop operation, else false.
|
||||
/// </summary>
|
||||
/// <param name="item">The ListViewItem to check.</param>
|
||||
public static bool GetIsUnderDragCursor( ListViewItem item )
|
||||
{
|
||||
return (bool)item.GetValue( IsUnderDragCursorProperty );
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Sets the IsUnderDragCursor attached property for the specified ListViewItem.
|
||||
/// </summary>
|
||||
/// <param name="item">The ListViewItem to set the property on.</param>
|
||||
/// <param name="value">Pass true if the element is underneath the drag cursor, else false.</param>
|
||||
internal static void SetIsUnderDragCursor( ListViewItem item, bool value )
|
||||
{
|
||||
item.SetValue( IsUnderDragCursorProperty, value );
|
||||
}
|
||||
|
||||
#endregion // IsUnderDragCursor
|
||||
}
|
||||
|
||||
#endregion // ListViewItemDragState
|
||||
|
||||
#region ProcessDropEventArgs
|
||||
|
||||
/// <summary>
|
||||
/// Event arguments used by the ListViewDragDropManager.ProcessDrop event.
|
||||
/// </summary>
|
||||
/// <typeparam name="ItemType">The type of data object being dropped.</typeparam>
|
||||
public class ProcessDropEventArgs<ItemType> : EventArgs where ItemType : class
|
||||
{
|
||||
#region Data
|
||||
|
||||
ObservableCollection<ItemType> itemsSource;
|
||||
ItemType dataItem;
|
||||
int oldIndex;
|
||||
int newIndex;
|
||||
DragDropEffects allowedEffects = DragDropEffects.None;
|
||||
DragDropEffects effects = DragDropEffects.None;
|
||||
|
||||
#endregion // Data
|
||||
|
||||
#region Constructor
|
||||
|
||||
internal ProcessDropEventArgs(
|
||||
ObservableCollection<ItemType> itemsSource,
|
||||
ItemType dataItem,
|
||||
int oldIndex,
|
||||
int newIndex,
|
||||
DragDropEffects allowedEffects )
|
||||
{
|
||||
this.itemsSource = itemsSource;
|
||||
this.dataItem = dataItem;
|
||||
this.oldIndex = oldIndex;
|
||||
this.newIndex = newIndex;
|
||||
this.allowedEffects = allowedEffects;
|
||||
}
|
||||
|
||||
#endregion // Constructor
|
||||
|
||||
#region Public Properties
|
||||
|
||||
/// <summary>
|
||||
/// The items source of the ListView where the drop occurred.
|
||||
/// </summary>
|
||||
public ObservableCollection<ItemType> ItemsSource
|
||||
{
|
||||
get { return this.itemsSource; }
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// The data object which was dropped.
|
||||
/// </summary>
|
||||
public ItemType DataItem
|
||||
{
|
||||
get { return this.dataItem; }
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// The current index of the data item being dropped, in the ItemsSource collection.
|
||||
/// </summary>
|
||||
public int OldIndex
|
||||
{
|
||||
get { return this.oldIndex; }
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// The target index of the data item being dropped, in the ItemsSource collection.
|
||||
/// </summary>
|
||||
public int NewIndex
|
||||
{
|
||||
get { return this.newIndex; }
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// The drag drop effects allowed to be performed.
|
||||
/// </summary>
|
||||
public DragDropEffects AllowedEffects
|
||||
{
|
||||
get { return allowedEffects; }
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// The drag drop effect(s) performed on the dropped item.
|
||||
/// </summary>
|
||||
public DragDropEffects Effects
|
||||
{
|
||||
get { return effects; }
|
||||
set { effects = value; }
|
||||
}
|
||||
|
||||
#endregion // Public Properties
|
||||
}
|
||||
|
||||
#endregion // ProcessDropEventArgs
|
||||
}
|
||||
Reference in New Issue
Block a user