[Resolved] TTreeView Changing Arrow based on Selection Status
lazarus / 31-LCL

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daz · 2018-11-25 20:59

I am doing a lot of color customization / butchering with TTreeView 

One of things I have done is changed the selection color and enabled
RowSelect

OnCustomDrawArrow works great, except I don't think there's a way to
tell if the current item the arrow being drawn for is a selected item
or not.

For example, see my attached screenshots.

I would like that if I am drawing the arrow for the currently selected
node, I would draw the arrow in a different color (black).

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 procedure
TfrmMain.tvNotebookCustomDrawArrow(Sender: TCustomTreeView;  const
ARect: TRect; ACollapsed: Boolean);var  points: array of TPoint;begin 
Sender.Canvas.Brush.Color := clBlack;  Sender.Canvas.FillRect(ARect); 
Sender.Canvas.Pen.Width := 0;  Sender.Canvas.Pen.Color := clWhite; 
Sender.Canvas.Brush.Color := clWhite;  if ACollapsed then begin   
SetLength(points, 3);    points[0] := Point(ARect.Left, ARect.Top);  
points[1] := Point(ARect.Left, ARect.Top + ARect.Height);    points[2]
:= Point(ARect.Left + ARect.Width, ARect.Top + ARect.Height div 2);  
Sender.Canvas.Polygon(points);  end else begin    SetLength(points,
3);    points[0] := Point(ARect.Left, ARect.Top);    points[1] :=
Point(ARect.Left + ARect.Width, ARect.Top);    points[2] :=
Point(ARect.Left + ARect.Width div 2, ARect.Top + ARect.Height);   
Sender.Canvas.Polygon(points);  end;  Sender.Canvas.Brush.Style :=
bsClear;end;

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wp · 2018-11-25 21:32

Use the method GetNodeAt(X,Y) to determine the node from the rectangle
passed as a parameter:

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 procedure
TForm1.TreeView1CustomDrawArrow(Sender: TCustomTreeView;  const ARect:
TRect; ACollapsed: Boolean);var  node: TTreeNode;begin  node :=
Sender.GetNodeAt(ARect.Left+1, ARect.Top+1);  if node =
Sender.Selected then begin      // this is for selected node  end
else    // this is for normal nodeend;

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daz · 2018-11-25 21:54

This works perfect, thanks a bunch!