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Author Topic: [Solved] VirtualDrawTree question-Child displayed in wrong location  (Read 2133 times)

bobonwhidbey

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I haven't been able to find a good example using the TVirtualDrawTree so I'm stumbling in the dark. This simple example I've put together has a record with only the one Caption:string. Here's how I'm adding root and child records...seems to be working:
Code: Pascal  [Select][+][-]
  1. procedure TForm.VDTaddClick(Sender: TObject);
  2. var
  3.   Data: PMyRec;
  4.   Node: PVirtualNode;
  5. begin
  6.   with VDT do
  7.     case (Sender as TButton).Tag of
  8.       0:
  9.       begin // add to root
  10.         Node := VDT.AddChild(nil);
  11.         Data := VDT.GetNodeData(Node);
  12.         Data^.Caption := 'Root ' + IntToStr(RootNodeCount);
  13.       end;
  14.       1: if Assigned(FocusedNode) then  // add as child
  15.         begin
  16.           ChildCount[FocusedNode] := ChildCount[FocusedNode] + 1;
  17.           Expanded[FocusedNode] := True;
  18.           InvalidateToBottom(FocusedNode);
  19.           Node := VDT.AddChild(nil);
  20.           Data := VDT.GetNodeData(Node);
  21.           Data^.Caption := 'Child ' + IntToStr(RootNodeCount);
  22. //          Data^.Caption := 'Child ' + IntToStr(Node.Index);
  23.         end;
  24.     end;
  25. end;
  26.  

When I display the tree with this, you can see, in the attachment, that the tree indentions seem to be correct but the text is showing up at the bottom, like a main root record rather than a child record.

Code: Pascal  [Select][+][-]
  1. procedure TForm.VDTDrawNode(Sender: TBaseVirtualTree; const PaintInfo: TVTPaintInfo);
  2. var
  3.   Data: PMyRec;
  4.   R: TRect;
  5.   I, w: integer;
  6.   s, s1: string;
  7. begin
  8.   with Sender as TVirtualDrawTree, PaintInfo do
  9.   begin
  10.     Data := VDT.GetNodeData(Node);
  11.     SetBKMode(Canvas.Handle, TRANSPARENT);
  12.     R := ContentRect;
  13.     if vsSelected in Node^.States then
  14.       Canvas.Font.Color := clWhite
  15.     else
  16.       Canvas.Font.Color := clBlack;
  17.     s := Data^.Caption;
  18.     DrawText(Canvas.Handle, PChar(s), Length(s), R, DT_LEFT or
  19.       DT_BOTTOM or DT_SINGLELINE);
  20.   end;
  21. end;
  22.  

Can someone provide help or a good VDT example?
« Last Edit: June 18, 2021, 07:53:15 pm by bobonwhidbey »
Win10 64-bit / Lazarus 32-bit 2.0.12 / FPC 3.2.0

jamie

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Re: VirtualDrawTree question-Child displayed in wrong location
« Reply #1 on: June 17, 2021, 02:30:45 am »
Try the CELLRECT instead for the text out...
The only true wisdom is knowing you know nothing

bobonwhidbey

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Re: VirtualDrawTree question-Child displayed in wrong location
« Reply #2 on: June 17, 2021, 02:36:32 am »
Same problem :(  Attached shows the results after adding 3 at the root, then selecting the middle line and adding a child.
Code: Pascal  [Select][+][-]
  1.   with Sender as TVirtualDrawTree, PaintInfo do
  2.   begin
  3.     Data := VDT.GetNodeData(Node);
  4.     s := Data^.Caption;
  5.     SetBKMode(Canvas.Handle, TRANSPARENT);
  6.     if vsSelected in Node^.States then
  7.       Canvas.Font.Color := clWhite
  8.     else
  9.       Canvas.Font.Color := clBlack;
  10.     R := CellRect;
  11.     DrawText(Canvas.Handle, PChar(s), Length(s), R, DT_LEFT or
  12.       DT_BOTTOM or DT_SINGLELINE);
  13.   end;
  14.  
« Last Edit: June 17, 2021, 02:38:07 am by bobonwhidbey »
Win10 64-bit / Lazarus 32-bit 2.0.12 / FPC 3.2.0

jamie

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Re: VirtualDrawTree question-Child displayed in wrong location
« Reply #3 on: June 17, 2021, 02:54:13 am »
you add a child node but you don't give it a parent node so its just going to keep showing in the root path..

on the second case step, use the focused node for example as the parent node instead of nil
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