/**
* Called when the mouse was moved during a drag and drop operation
*
* @param DragDropEvent The event that describes this drag drop operation.
*/
void FDockingDragOperation::OnDragged( const FDragDropEvent& DragDropEvent )
{
const bool bPreviewingTarget = HoveredDockTarget.TargetNode.IsValid();
if ( !bPreviewingTarget )
{
// The tab is being dragged. Move the the decorator window to match the cursor position.
FVector2D TargetPosition = DragDropEvent.GetScreenSpacePosition() - GetDecoratorOffsetFromCursor();
CursorDecoratorWindow->UpdateMorphTargetShape( FSlateRect(TargetPosition.X, TargetPosition.Y, TargetPosition.X + LastContentSize.X, TargetPosition.Y + LastContentSize.Y) );
CursorDecoratorWindow->MoveWindowTo( TargetPosition );
}
}
/**
* Invoked when the drag and drop operation has ended.
*
* @param bDropWasHandled true when the drop was handled by some widget; false otherwise
*/
void FDockingDragOperation::OnDrop( bool bDropWasHandled, const FPointerEvent& MouseEvent )
{
check(CursorDecoratorWindow.IsValid());
const FVector2D WindowSize = CursorDecoratorWindow->GetSizeInScreen();
// Destroy the CursorDecoratorWindow by calling the base class implementation because we are relocating the content into a more permanent home.
FDragDropOperation::OnDrop(bDropWasHandled, MouseEvent);
TabBeingDragged->SetDraggedOverDockArea( NULL );
if (!bDropWasHandled)
{
// If we dropped the tab into an existing DockNode then it would have handled the DropEvent.
// We are here because that didn't happen, so make a new window with a new DockNode and drop the tab into that.
const FVector2D PositionToDrop = MouseEvent.GetScreenSpacePosition() - GetDecoratorOffsetFromCursor();
TSharedRef<FTabManager> MyTabManager = TabBeingDragged->GetTabManager();
TSharedPtr<SWindow> NewWindowParent = MyTabManager->GetPrivateApi().GetParentWindow();
TSharedRef<SWindow> NewWindow = SNew(SWindow)
.Title( FGlobalTabmanager::Get()->GetApplicationTitle() )
.AutoCenter(EAutoCenter::None)
.ScreenPosition( PositionToDrop )
// Make room for the title bar; otherwise windows will get progressive smaller whenver you float them.
.ClientSize( SWindow::ComputeWindowSizeForContent( WindowSize ) )
.CreateTitleBar(false);
TSharedPtr<SDockingTabStack> NewDockNode;
if ( TabBeingDragged->GetTabRole() == ETabRole::NomadTab )
{
TabBeingDragged->SetTabManager(FGlobalTabmanager::Get());
}
// Create a new dockarea
TSharedRef<SDockingArea> NewDockArea =
SNew(SDockingArea, TabBeingDragged->GetTabManager(), FTabManager::NewPrimaryArea())
. ParentWindow( NewWindow )
. InitialContent
(
SAssignNew(NewDockNode, SDockingTabStack, FTabManager::NewStack())
);
if (TabBeingDragged->GetTabRole() == ETabRole::MajorTab || TabBeingDragged->GetTabRole() == ETabRole::NomadTab)
{
TSharedPtr<SWindow> RootWindow = FGlobalTabmanager::Get()->GetRootWindow();
if ( RootWindow.IsValid() )
{
// We have a root window, so all MajorTabs are nested under it.
FSlateApplication::Get().AddWindowAsNativeChild( NewWindow, RootWindow.ToSharedRef() )->SetContent(NewDockArea);
}
else
{
// App tabs get put in top-level windows. They show up on the taskbar.
FSlateApplication::Get().AddWindow( NewWindow )->SetContent(NewDockArea);
}
}
else
{
// Other tab types are placed in child windows. Their life is controlled by the top-level windows.
// They do not show up on the taskbar.
if ( NewWindowParent.IsValid() )
{
FSlateApplication::Get().AddWindowAsNativeChild( NewWindow, NewWindowParent.ToSharedRef() )->SetContent(NewDockArea);
}
else
{
FSlateApplication::Get().AddWindow( NewWindow )->SetContent(NewDockArea);
}
}
// Do this after the window parenting so that the window title is set correctly
NewDockNode->OpenTab(TabBeingDragged.ToSharedRef());
// Let every widget under this tab manager know that this tab has found a new home.
TabOwnerAreaOfOrigin->GetTabManager()->GetPrivateApi().OnTabRelocated( TabBeingDragged.ToSharedRef(), NewWindow );
}
else
{
// The event was handled, so we HAVE to have some window that we dropped onto.
TSharedRef<SWindow> WindowDroppedInto = MouseEvent.GetWindow();
// Let every widget under this tab manager know that this tab has found a new home.
TSharedPtr<SWindow> NewWindow = ( TabOwnerAreaOfOrigin->GetParentWindow() == WindowDroppedInto )
// Tab dropped into same window as before, meaning there is no NewWindow.
? TSharedPtr<SWindow>()
// Tab was dropped into a different window, so the tab manager needs to know in order to re-parent child windows.
: WindowDroppedInto;
TabOwnerAreaOfOrigin->GetTabManager()->GetPrivateApi().OnTabRelocated( TabBeingDragged.ToSharedRef(), WindowDroppedInto );
}
}