/// <summary>
/// Occurs when dragging ends because of dropping.
/// </summary>
/// <param name="screenPt">Ending screen point when dropping.</param>
/// <returns>Drop was performed and the source can perform any removal of pages as required.</returns>
public virtual bool DragEnd(Point screenPt)
{
if (IsDisposed)
{
throw new InvalidOperationException("Cannot DragEnd when instance have been disposed.");
}
if (!IsDragging)
{
throw new InvalidOperationException("Cannot DragEnd when DragStart has not been called.");
}
// Different feedback objects implement visual feeback differently and so only the feedback
// instance knows the correct target to use for the given screen point and drag data.
_currentTarget = _dragFeedback.Feedback(screenPt, _currentTarget);
// Remove visual feedback
_dragFeedback.Quit();
// Inform target it needs to perform the drop action
bool ret = false;
if (_currentTarget != null)
{
ret = _currentTarget.PerformDrop(screenPt, _pageDragEndData);
}
ClearTargets();
RestoreCursor();
EndDragging();
return(ret);
}
private DockCluster FindTargetCluster(DragTarget target)
{
foreach (DockCluster cluster in _clusters)
{
if (!cluster.ExcludeCluster && cluster.ScreenRect.Equals(target.ScreenRect))
{
return(cluster);
}
}
return(null);
}
/// <summary>
/// Initialize a new instance of the DockCluster class.
/// </summary>
/// <param name="paletteDragDrop">Drawing palette.</param>
/// <param name="renderer">Drawing renderer.</param>
/// <param name="target">Initial target for the cluster.</param>
public DockCluster(IPaletteDragDrop paletteDragDrop,
IRenderer renderer,
DragTarget target)
{
_paletteDragDrop = paletteDragDrop;
_renderer = renderer;
_screenRect = target.ScreenRect;
_drawRect = target.DrawRect;
_hintToTarget = new HintToTarget();
_hintToTarget.Add(target.Hint & DragTargetHint.ExcludeFlags, target);
_excludeCluster = (target.Hint & DragTargetHint.ExcludeCluster) == DragTargetHint.ExcludeCluster;
}
/// <summary>
/// Add the new target to the cluster.
/// </summary>
/// <param name="target">Target to add into cluster.</param>
public void Add(DragTarget target)
{
// Find the hint that excludes extra flags
DragTargetHint hint = target.Hint & DragTargetHint.ExcludeFlags;
// Can only add one of each hint value
if (!_hintToTarget.ContainsKey(hint))
{
_hintToTarget.Add(hint, target);
// Make sure the drawing rectangle encloses all targets
DrawRect = Rectangle.Union(DrawRect, target.DrawRect);
}
}
private void ClearTargets()
{
if (_dragTargets != null)
{
// Dispose the targets to ensure references are removed to prevent memory leaks
foreach (DragTarget target in _dragTargets)
{
target.Dispose();
}
_dragTargets.Clear();
}
_currentTarget = null;
}
/// <summary>
/// Occurs on dragging movement.
/// </summary>
/// <param name="screenPt">Latest screen point during dragging.</param>
public virtual void DragMove(Point screenPt)
{
if (IsDisposed)
{
throw new InvalidOperationException("Cannot DragMove when instance have been disposed.");
}
if (!IsDragging)
{
throw new InvalidOperationException("Cannot DragMove when DragStart has not been called.");
}
// Different feedback objects implement visual feeback differently and so only the feedback
// instance knows the correct target to use for the given screen point and drag data.
_currentTarget = _dragFeedback.Feedback(screenPt, _currentTarget);
// Check if we need a cursor to indicate the drag state
UpdateCursor();
}
/// <summary>
/// Called to request feedback be shown for the specified target.
/// </summary>
/// <param name="screenPt">Current screen point of mouse.</param>
/// <param name="target">Target that needs feedback.</param>
/// <returns>Updated drag target.</returns>
public override DragTarget Feedback(Point screenPt, DragTarget target)
{
// If the current target no longer matches the new point, we need a new target.
if ((target != null) && !target.IsMatch(screenPt, PageDragEndData))
{
target = null;
}
// Only find a new target if we do not already have a target
if (target == null)
{
target = FindTarget(screenPt, PageDragEndData);
}
if (_solid != null)
{
_solid.SolidRect = (target != null) ? target.DrawRect : Rectangle.Empty;
}
return(target);
}
/// <summary>
/// Called to request feedback be shown for the specified target.
/// </summary>
/// <param name="screenPt">Current screen point of mouse.</param>
/// <param name="target">Target that needs feedback.</param>
/// <returns>Updated drag target.</returns>
public override DragTarget Feedback(Point screenPt, DragTarget target)
{
DragTarget matchTarget = null;
// Update each cluster so it shows/hides docking indicators based on mouse position
foreach (DockCluster cluster in _clusters)
{
DragTarget clusterTarget = cluster.Feedback(screenPt, _dragFeedback);
// We use the first matching target found in a cluster
if ((clusterTarget != null) && (matchTarget == null))
{
matchTarget = clusterTarget;
}
}
// Update the solid feedback rectangle with area of the specific target
if (_solid != null)
{
_solid.SolidRect = (matchTarget != null) ? matchTarget.DrawRect : Rectangle.Empty;
}
return(matchTarget);
}
/// <summary> /// Called to request feedback be shown for the specified target. /// </summary> /// <param name="screenPt">Current screen point of mouse.</param> /// <param name="target">Target that needs feedback.</param> /// <returns>Updated drag target.</returns> public abstract DragTarget Feedback(Point screenPt, DragTarget target);