public override bool Merge(CommandItem newitem) { SelectionMovedOrResizedCI newitemx = newitem as SelectionMovedOrResizedCI; // Ensure items are of the same type. if (newitemx == null || newitemx._editingOperationCount != _editingOperationCount || !StrokeCollectionsAreEqual(newitemx._selection, _selection)) { return(false); } // Keep former oldrect, latter newrect. _newrect = newitemx._newrect; return(true); }
public override bool Merge(CommandItem newitem) { StrokesAddedOrRemovedCI newitemx = newitem as StrokesAddedOrRemovedCI; if (newitemx == null || newitemx._editingMode != _editingMode || newitemx._editingOperationCount != _editingOperationCount) { return(false); } // We only implement merging for repeated point-erase operations. if (_editingMode != InkCanvasEditingMode.EraseByPoint) { return(false); } if (newitemx._editingMode != InkCanvasEditingMode.EraseByPoint) { return(false); } // Note: possible for point-erase to have hit intersection of >1 strokes! // For each newly hit stroke, merge results into this command item. foreach (Stroke doomed in newitemx._removed) { if (_added.Contains(doomed)) { _added.Remove(doomed); } else { _removed.Add(doomed); } } _added.Add(newitemx._added); return(true); }
/// <summary> /// Take the top item off the command stack. /// </summary> public void Redo() { if (!CanRedo) { throw new InvalidOperationException(); } CommandItem item = _redoStack.Pop(); // Invoke the redo operation, with change-tracking temporarily suspended. _disableChangeTracking = true; try { item.Redo(); } finally { _disableChangeTracking = false; } //place this item on the undo stack _undoStack.Push(item); }
// Allows multiple subsequent commands of the same type to roll-up into one // logical undoable/redoable command -- return false if newitem is incompatable. public abstract bool Merge(CommandItem newitem);