(Almost) finished the 'custom triangle view control'...

Well, actually it's just a workaround to intercept keystrokes...
It still can't even catch arrow-keys, looks like I missed something... :-\

2.10/Source/CustomDrawControl.pas

@@ -0,0 +1,62 @@
+unit CustomDrawControl;
+
+interface
+
+uses
+  Classes, Controls, Messages, Windows, Graphics;
+
+type
+  TCustomDrawControl = class(TCustomControl)
+  private
+    FOnPaint: TNotifyEvent;
+
+    procedure WMEraseBkgnd(var Message: TWMEraseBkgnd); message WM_ERASEBKGND;
+//    procedure WMSetFocus(var Message: TWMSetFocus); message WM_SETFOCUS;
+//    procedure WMKillFocus(var Message: TWMKillFocus); message WM_KILLFOCUS;
+  protected
+
+  public
+    procedure Paint; override;
+
+    property OnPaint: TNotifyEvent read FOnPaint write FOnPaint;
+    property Canvas;
+
+    property OnDblClick;
+    property OnKeyDown;
+//    property OnKeyPress;
+//    property OnKeyUp;
+    property OnMouseDown;
+    property OnMouseMove;
+    property OnMouseUp;
+    property OnMouseWheel;
+//    property OnMouseWheelDown;
+//    property OnMouseWheelUp;
+    property OnEnter;
+    property OnExit;
+  end;
+
+implementation
+
+procedure TCustomDrawControl.WMEraseBkgnd(var Message: TWMEraseBkgnd);
+begin
+  Message.Result := 1;
+end;
+
+{
+procedure TCustomDrawControl.WMSetFocus(var Message: TWMSetFocus);
+begin
+  Invalidate;
+end;
+
+procedure TCustomDrawControl.WMKillFocus(var Message: TWMKillFocus);
+begin
+  Invalidate;
+end;
+}
+
+procedure TCustomDrawControl.Paint;
+begin
+  if Assigned(FOnPaint) then FOnPaint(Self);
+end;
+
+end.