TdxLayoutSplitterItem.OnOpened Event

Allows you to respond to a layout splitter expand operation.

Declaration

property OnOpened: TdxLayoutSplitterItemMovedEvent read; write;

Remarks

Handle OnOpened and OnClosed events to execute custom code in response to splitter expand and collapse operations.

Event Occurrence

The OnOpened event occurs every time the splitter expands its target layout item.

Event Parameters

Sender

Provides access to the layout splitter that raised the expand event.

AArgs

Allows you to access layout items delimited by the Sender splitter and identify item boundaries before and after the expand operation.

Refer to the TdxLayoutSplitterItemMovedEvent procedural type description for detailed information on all parameters accessible within an OnOpened event handler.

Code Example: Keep Only One Grouped Layout Item Expanded at a Time

The code example in this section demonstrates OnClosed and OnOpened event handlers that allow you to keep only one layout item expanded within a layout group that contains items delimited by splitters. The form’s OnCreate event handler assigns the same event handlers to all splitters within the target group.

Delphi

procedure TMyForm.SplitterItemClosed(Sender: TdxLayoutSplitterItem;
  AArgs: TdxLayoutSplitterItemMovedEventArgs);
var
  I: Integer;
begin
  for I := 0 to dxLayoutGroup1.Count - 1 do
    if((dxLayoutGroup1.Items[I].ClassType = TdxLayoutSplitterItem) and
      (dxLayoutGroup1.Items[I] <> Sender)) then
      if (dxLayoutGroup1.Items[I] as TdxLayoutSplitterItem).IsClosed then
        (dxLayoutGroup1.Items[I] as TdxLayoutSplitterItem).Open;
end;

procedure TMyForm.SplitterItemOpened(Sender: TdxLayoutSplitterItem;
  AArgs: TdxLayoutSplitterItemMovedEventArgs);
var
  I: Integer;
begin
  for I := 0 to dxLayoutGroup1.Count - 1 do
    if ((dxLayoutGroup1.Items[I].ClassType = TdxLayoutSplitterItem) and
       (dxLayoutGroup1.Items[I] <> Sender)) then
       if not (dxLayoutGroup1.Items[I] as TdxLayoutSplitterItem).IsClosed then
         (dxLayoutGroup1.Items[I] as TdxLayoutSplitterItem).Close;
end;

procedure TMyForm.FormCreate(Sender: TObject);
var
  I: Integer;
begin
  for I := 0 to dxLayoutGroup1.Count - 1 do
    if(dxLayoutGroup1.Items[I].ClassType = TdxLayoutSplitterItem) then
    begin
      (dxLayoutGroup1.Items[I] as TdxLayoutSplitterItem).AllowCloseOnClick := True;
      (dxLayoutGroup1.Items[I] as TdxLayoutSplitterItem).OnOpened := SplitterItemOpened;
      (dxLayoutGroup1.Items[I] as TdxLayoutSplitterItem).OnClosed := SplitterItemClosed;
    end;
end;

C++

void __fastcall TMyForm::SplitterItemClosed(TdxLayoutSplitterItem *Sender,
  TdxLayoutSplitterItemMovedEventArgs *AArgs)
{
  for(int i = 0; i < dxLayoutGroup1->Count; i++)
  {
    if((dxLayoutGroup1->Items[i]->ClassType() == __classid(TdxLayoutSplitterItem)) &&
      (dxLayoutGroup1->Items[i] != Sender))
      {
        if(dynamic_cast<TdxLayoutSplitterItem*>(dxLayoutGroup1->Items[i]->IsClosed))
          dynamic_cast<TdxLayoutSplitterItem*>(dxLayoutGroup1->Items[i])->Open();
      }
  }
}

void __fastcall TMyForm::SplitterItemOpened(TdxLayoutSplitterItem *Sender,
  TdxLayoutSplitterItemMovedEventArgs *AArgs)
{
  for(int i = 0; i < dxLayoutGroup1->Count; i++)
  {
    if((dxLayoutGroup1->Items[i]->ClassType() == __classid(TdxLayoutSplitterItem)) &&
      (dxLayoutGroup1->Items[i] != Sender))
      {
        if(!dynamic_cast<TdxLayoutSplitterItem*>(dxLayoutGroup1->Items[i]->IsClosed))
          dynamic_cast<TdxLayoutSplitterItem*>(dxLayoutGroup1->Items[i])->Close();
      }
  }
}

void __fastcall TMyForm::FormCreate(TObject *Sender)
{
  for(int i = 0; i < dxLayoutGroup1->Count; i++)
  {
    if(dxLayoutGroup1->Items[i]->ClassType == __classid(TdxLayoutSplitterItem))
    {
      dynamic_cast<TdxLayoutSplitterItem*>(dxLayoutGroup1->Items[i])->AllowCloseOnClick = true;
      dynamic_cast<TdxLayoutSplitterItem*>(dxLayoutGroup1->Items[i])->OnOpened = SplitterItemOpened;
      dynamic_cast<TdxLayoutSplitterItem*>(dxLayoutGroup1->Items[i])->OnClosed = SplitterItemClosed;
    }
  }
}