private void Button_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
Button button = sender as Button;
if (button?.DataContext == null)
{
return;
}
GridCell gridCellVM = button.DataContext as GridCell;
if (gridCellVM == null)
{
return;
}
GridLayoutViewModel vm = GridLayoutViewModel;
if (vm == null)
{
return;
}
if ((Keyboard.IsKeyDown(Key.LeftShift) || Keyboard.IsKeyDown(Key.RightShift)) && vm.SelectedCells.Count > 0)
{
GridCell lastSelected = vm.SelectedCells[vm.SelectedCells.Count - 1];
System.Drawing.Rectangle extent = System.Drawing.Rectangle.Union(lastSelected.CellExtent, gridCellVM.CellExtent);
Dictionary <GridCell, GridCell> selectSet = new Dictionary <GridCell, GridCell>();
foreach (GridCell cell in vm.SelectedCells)
{
selectSet[cell] = cell;
extent = System.Drawing.Rectangle.Union(cell.CellExtent, extent);
}
while (true)
{
int selCount = 0;
foreach (GridCell cell in vm.GridElements)
{
if (cell.CellExtent.IntersectsWith(extent))
{
if (selectSet.ContainsKey(cell))
{
continue;
}
extent = System.Drawing.Rectangle.Union(cell.CellExtent, extent);
vm.AddToSelection(cell);
selectSet[cell] = cell;
selCount++;
}
else
{
cell.IsHighlighted = false;
}
}
if (selCount == 0)
{
break;
}
}
}
else
{
if (!Keyboard.IsKeyDown(Key.LeftCtrl) && !Keyboard.IsKeyDown(Key.RightCtrl))
{
vm.ClearSelection();
}
if (vm.SelectedCells.Contains(gridCellVM))
{
gridCellVM.IsSelected = false;
gridCellVM.IsHighlighted = false;
vm.RemoveFromSelection(gridCellVM);
}
else
{
gridCellVM.IsSelected = true;
gridCellVM.IsHighlighted = true;
vm.AddToSelection(gridCellVM);
}
if (vm.SelectedCells.Count == 0)
{
return;
}
}
}
