VirtualStringTree and PaintText
lazarus / 21-General

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bobonwhidbey · 2021-06-13 17:58

I'm just starting to learn about all the amazing capabilities of
TVirtualStringTree. I think a whole book might be written on it with
all it's properties and options. I'd like to be able to "paint" the
text area. I was hoping that something like this in onPaintText would
work.
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i     Data :=
VST.GetNodeData(Node);    TargetCanvas.TextOut(x,y,Data.Text);
In this manner I could have some of the text in one color, and some in
another. I also need to stop the text from being painted by the
component.

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winni · 2021-06-13 18:20

Hi!

Look at  the example page of VirtualTreeView and look at the
onPaintText section:

https://wiki.freepascal.org/VirtualTreeview_Example_for_Lazarus

Winni

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balazsszekely · 2021-06-13 18:23

@bobonwhidbey
QuoteI'm just starting to learn about all the amazing capabilities of
TVirtualStringTree. I think a whole book might be written on it with
all it's properties and options. I'd like to be able to "paint" the
text area. I was hoping that something like this in onPaintText would
work.Try something like this:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i type  PData
= ^TData;  TData = record    FBold: Boolean;    FColored: Boolean; 
end; procedure TForm1.VSTPaintText(Sender: TBaseVirtualTree;  const
TargetCanvas: TCanvas; Node: PVirtualNode; Column: TColumnIndex; 
TextType: TVSTTextType);var  Data: PData;begin  if TextType <>
ttNormal then    Exit;  Data := VST.GetNodeData(Node);  case Column
of    -1: begin //if no columns are defined, the case is not needed  
     if Data^.FBold then           TargetCanvas.Font.Style :=
TargetCanvas.Font.Style + [fsBold];          if Data^.FColored then  
       if Node = Sender.FocusedNode then           
 TargetCanvas.Font.Color := VST.Colors.SelectionTextColor         
 else             TargetCanvas.Font.Color := clRed;       end;    0:
begin         //each column has different font       end;   
end;end; procedure TForm1.Button1Click(Sender: TObject);var  Node:
PVirtualNode;  Data: PData;begin  Node := VST.AddChild(nil);  Data :=
VST.GetNodeData(Node);  Data^.FBold := True;  Data^.FColored :=
False;   Node := VST.AddChild(nil);  Data := VST.GetNodeData(Node); 
Data^.FBold := False;  Data^.FColored := True;end;

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bobonwhidbey · 2021-06-13 18:45

The examples and GetMem's approach seem to require that the text for
the entire column must use the same font attributes. I want to have
some text in one color/style and other parts of the text in another.

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balazsszekely · 2021-06-13 18:54

@ bobonwhidbey
QuoteThe examples and GetMem's approach seem to require that the text
for the entire column must use the same font attributes. I want to
have some text in one color/style and other parts of the text in
another.
If you wish to have full control over the drawing then VirtualDrawTree
is a much better option. You can find an example in the following
post(see attachment):
https://forum.lazarus.freepascal.org/index.php/topic,37834.msg257241.h
tml#msg257241

Please check the VDTDrawNode event.