Example #1
0
        private static void DragSource_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            // Ignore the click if the user has clicked on a scrollbar.
            if (HitTestScrollBar(sender, e))
            {
                _dragInfo = null;
                return;
            }

            _dragInfo = new DragInfo(sender, e);

            // If the sender is a list box that allows multiple selections, ensure that clicking on an
            // already selected item does not change the selection, otherwise dragging multiple items
            // is made impossible.
            var itemsControl = sender as ItemsControl;

            if (_dragInfo.VisualSourceItem == null || itemsControl == null || !itemsControl.CanSelectMultipleItems())
            {
                return;
            }

            var selectedItems = itemsControl
                                .GetSelectedItems()
                                .Cast <object>()
                                .ToList();

            if (selectedItems.Count() <= 1 || !selectedItems.Contains(_dragInfo.SourceItem))
            {
                return;
            }

            _clickSupressItem = _dragInfo.SourceItem;
            e.Handled         = true;
        }
Example #2
0
    /// <summary>
    /// Initializes a new instance of the DropInfo class.
    /// </summary>
    /// <param name="sender">
    /// The sender of the drag event.
    /// </param>
    /// <param name="e">
    /// The drag event.
    /// </param>
    /// <param name="dragInfo">
    /// Information about the source of the drag, if the drag came from within the framework.
    /// </param>
    public DropInfo(object sender, DragEventArgs e, DragInfo dragInfo)
    {
      string dataFormat = DragDrop.DataFormat.Name;
      Data = (e.Data.GetDataPresent(dataFormat)) ? e.Data.GetData(dataFormat) : e.Data;
      DragInfo = dragInfo;

      VisualTarget = sender as UIElement;
      if (VisualTarget == null)
        return;

      DropPosition = e.GetPosition(VisualTarget);

      if (!(sender is ItemsControl))
        return;

      var itemsControl = (ItemsControl)sender;
      UIElement item = itemsControl.GetItemContainerAt(DropPosition);
      bool directlyOverItem = item != null;

      TargetGroup = FindGroup(itemsControl, DropPosition);
      VisualTargetOrientation = itemsControl.GetItemsPanelOrientation();

      if (item == null)
      {
        item = itemsControl.GetItemContainerAt(DropPosition, VisualTargetOrientation);
        directlyOverItem = false;
      }

      if (item == null)
      {
        TargetCollection = itemsControl.ItemsSource ?? itemsControl.Items;
        InsertIndex = itemsControl.Items.Count;
        return;
      }
      
      ItemsControl itemParent = ItemsControl.ItemsControlFromItemContainer(item);

      InsertIndex = itemParent.ItemContainerGenerator.IndexFromContainer(item);
      TargetCollection = itemParent.ItemsSource ?? itemParent.Items;

      if (directlyOverItem)
      {
        TargetItem = itemParent.ItemContainerGenerator.ItemFromContainer(item);
        VisualTargetItem = item;
      }

      if (VisualTargetOrientation == Orientation.Vertical)
      {
        if (e.GetPosition(item).Y > item.RenderSize.Height / 2)
          InsertIndex++;
      }
      else
      {
        if (e.GetPosition(item).X > item.RenderSize.Width / 2)
          InsertIndex++;
      }
    }
Example #3
0
        private static void DragSource_PreviewMouseMove(object sender, MouseEventArgs e)
        {
            if (_dragInfo == null || _dragInProgress)
            {
                return;
            }

            Point dragStart = _dragInfo.DragStartPosition;
            Point position  = e.GetPosition(null);

            if (Math.Abs(position.X - dragStart.X) <= SystemParameters.MinimumHorizontalDragDistance &&
                Math.Abs(position.Y - dragStart.Y) <= SystemParameters.MinimumVerticalDragDistance)
            {
                return;
            }

            IDragSource dragHandler = GetDragHandler(_dragInfo.VisualSource);

            if (dragHandler != null)
            {
                dragHandler.StartDrag(_dragInfo);
            }
            else
            {
                DefaultDragHandler.StartDrag(_dragInfo);
            }

            if (_dragInfo.Effects == DragDropEffects.None || _dragInfo.Data == null)
            {
                return;
            }

            var data = new DataObject(DataFormat.Name, _dragInfo.Data);

            try
            {
                _dragInProgress = true;
                System.Windows.DragDrop.DoDragDrop(_dragInfo.VisualSource, data, _dragInfo.Effects);
            }
            finally
            {
                _dragInProgress = false;
            }

            _dragInfo = null;
        }
Example #4
0
        private static void DragSource_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
        {
            // If we prevented the control's default selection handling in DragSource_PreviewMouseLeftButtonDown
            // by setting 'e.Handled = true' and a drag was not initiated, manually set the selection here.
            var itemsControl = sender as ItemsControl;

            if (itemsControl != null && _dragInfo != null && _clickSupressItem == _dragInfo.SourceItem)
            {
                if ((Keyboard.Modifiers & ModifierKeys.Control) != 0)
                {
                    itemsControl.SetItemSelected(_dragInfo.SourceItem, false);
                }
                else
                {
                    itemsControl.SetSelectedItem(_dragInfo.SourceItem);
                }
            }

            _dragInfo         = null;
            _clickSupressItem = null;
        }
Example #5
0
        /// <summary>
        /// Initializes a new instance of the DropInfo class.
        /// </summary>
        /// <param name="sender">
        /// The sender of the drag event.
        /// </param>
        /// <param name="e">
        /// The drag event.
        /// </param>
        /// <param name="dragInfo">
        /// Information about the source of the drag, if the drag came from within the framework.
        /// </param>
        public DropInfo(object sender, DragEventArgs e, DragInfo dragInfo)
        {
            string dataFormat = DragDrop.DataFormat.Name;

            Data     = (e.Data.GetDataPresent(dataFormat)) ? e.Data.GetData(dataFormat) : e.Data;
            DragInfo = dragInfo;

            VisualTarget = sender as UIElement;
            if (VisualTarget == null)
            {
                return;
            }

            DropPosition = e.GetPosition(VisualTarget);

            if (!(sender is ItemsControl))
            {
                return;
            }

            var       itemsControl     = (ItemsControl)sender;
            UIElement item             = itemsControl.GetItemContainerAt(DropPosition);
            bool      directlyOverItem = item != null;

            TargetGroup             = FindGroup(itemsControl, DropPosition);
            VisualTargetOrientation = itemsControl.GetItemsPanelOrientation();

            if (item == null)
            {
                item             = itemsControl.GetItemContainerAt(DropPosition, VisualTargetOrientation);
                directlyOverItem = false;
            }

            if (item == null)
            {
                TargetCollection = itemsControl.ItemsSource ?? itemsControl.Items;
                InsertIndex      = itemsControl.Items.Count;
                return;
            }

            ItemsControl itemParent = ItemsControl.ItemsControlFromItemContainer(item);

            InsertIndex      = itemParent.ItemContainerGenerator.IndexFromContainer(item);
            TargetCollection = itemParent.ItemsSource ?? itemParent.Items;

            if (directlyOverItem)
            {
                TargetItem       = itemParent.ItemContainerGenerator.ItemFromContainer(item);
                VisualTargetItem = item;
            }

            if (VisualTargetOrientation == Orientation.Vertical)
            {
                if (e.GetPosition(item).Y > item.RenderSize.Height / 2)
                {
                    InsertIndex++;
                }
            }
            else
            {
                if (e.GetPosition(item).X > item.RenderSize.Width / 2)
                {
                    InsertIndex++;
                }
            }
        }
Example #6
0
    private static void DragSource_PreviewMouseMove(object sender, MouseEventArgs e)
    {
      if (_dragInfo == null || _dragInProgress)
        return;
      
      Point dragStart = _dragInfo.DragStartPosition;
      Point position = e.GetPosition(null);

      if (Math.Abs(position.X - dragStart.X) <= SystemParameters.MinimumHorizontalDragDistance &&
          Math.Abs(position.Y - dragStart.Y) <= SystemParameters.MinimumVerticalDragDistance)
        return;
      
      IDragSource dragHandler = GetDragHandler(_dragInfo.VisualSource);

      if (dragHandler != null)
        dragHandler.StartDrag(_dragInfo);
      else
        DefaultDragHandler.StartDrag(_dragInfo);

      if (_dragInfo.Effects == DragDropEffects.None || _dragInfo.Data == null)
        return;

      var data = new DataObject(DataFormat.Name, _dragInfo.Data);

      try
      {
        _dragInProgress = true;
        System.Windows.DragDrop.DoDragDrop(_dragInfo.VisualSource, data, _dragInfo.Effects);
      }
      finally
      {
        _dragInProgress = false;
      }

      _dragInfo = null;
    }
Example #7
0
    private static void DragSource_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
    {
      // If we prevented the control's default selection handling in DragSource_PreviewMouseLeftButtonDown
      // by setting 'e.Handled = true' and a drag was not initiated, manually set the selection here.
      var itemsControl = sender as ItemsControl;

      if (itemsControl != null && _dragInfo != null && _clickSupressItem == _dragInfo.SourceItem)
      {
        if ((Keyboard.Modifiers & ModifierKeys.Control) != 0)
          itemsControl.SetItemSelected(_dragInfo.SourceItem, false);
        else
          itemsControl.SetSelectedItem(_dragInfo.SourceItem);
      }

      _dragInfo = null;
      _clickSupressItem = null;
    }
Example #8
0
    private static void DragSource_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
      // Ignore the click if the user has clicked on a scrollbar.
      if (HitTestScrollBar(sender, e))
      {
        _dragInfo = null;
        return;
      }

      _dragInfo = new DragInfo(sender, e);

      // If the sender is a list box that allows multiple selections, ensure that clicking on an 
      // already selected item does not change the selection, otherwise dragging multiple items 
      // is made impossible.
      var itemsControl = sender as ItemsControl;

      if (_dragInfo.VisualSourceItem == null || itemsControl == null || !itemsControl.CanSelectMultipleItems())
        return;

      var selectedItems = itemsControl
        .GetSelectedItems()
        .Cast<object>()
        .ToList();

      if (selectedItems.Count() <= 1 || !selectedItems.Contains(_dragInfo.SourceItem))
        return;

      _clickSupressItem = _dragInfo.SourceItem;
      e.Handled = true;
    }