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POHow to draw the element part in right to left (RTL) direction when drawing with DrawThemeBackground?
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copied!<p>I'm trying to draw the <code>ttGlyphClosed</code> element of <code>Explorer::Treeview</code> class in right to left direction (like when the <code>BiDiMode</code> would be <code>bdLeftToRight</code>). I have a problem, that I don't know how to make my offscreen bitmap to be transparent. The bitmap's background is always white.</p> <p>I'm using the following code to mirror the image:</p> <pre><code>procedure TForm5.FormPaint(Sender: TObject); var bm: TBitmap; ARect: TRect; Details: TThemedElementDetails; begin if ExplorerTreeviewhTheme = 0 then ExplorerTreeviewhTheme := OpenThemeData(0, 'Explorer::Treeview'); ARect := Rect(20, 20, 40, 40); Details := ThemeServices.GetElementDetails(ttGlyphClosed); DrawThemeBackground(ExplorerTreeviewhTheme, Canvas.Handle, Details.Part, Details.State, ARect, nil); //Ok bm := TBitmap.Create; try bm.Width := 20; bm.Height := 20; ARect := Rect(00, 00, 20, 20); DrawThemeBackground(ExplorerTreeviewhTheme, bm.Canvas.Handle, Details.Part, Details.State, ARect, nil); // rendered result has white background Canvas.Draw(60, 10, bm); // rendered result is mirrored but has also white background StretchBlt(Canvas.Handle, 100, 10, -20, 20, bm.Canvas.Handle, 0, 0, 20, 20, SRCCOPY); finally bm.Free; end; end; </code></pre> <p>The question is how to mirror element drawn by the <code>DrawThemeBackground</code> function (for RTL reading) or how to use this function for RTL (right to left) rendering ?</p>

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