[Lazarus] How to hide pop-up menu before taking a screen snapshot?

Bo Berglund bo.berglund at gmail.com
Sun Feb 7 10:37:07 CET 2021

I have worked on a tool to copy a region of the Windows desktop for use in
illustrations. The tool consists of a transparent form which is supposed to be
located on top of the area to copy.

This form has a pop-up menu where there are 3 items to select from:
- Copy image
- Copy position
- Close

When I use the "Copy image" function the resulting image contains the selected
menu item caption on top of the copied desktop bitmap...

I have tried various ways to get rid of this but everything I tried has failed.
So how can I hide the menu item caption in code before I make the image

I even added a timer set to 50 ms interval and put the image copy in its ontimer
event hoping that the menu click should have exited and the text disappeared
before the image copy happened, but no go...

Here is the way the copy is commanded via the popup menu:

And here is a captured image where the popup caption is visible:

As you can see the caption of the clicked menu item is still present in the
screenshot image...

Here is parts of the code:

procedure TfrmMain.miCopyImageClick(Sender : TObject);
  //CopyScreenRect;  //Moved to timer
  //miCopyImage.Visible := false; //Does not work
  //self.Refresh;  //Does not work
  timCopyImg.Enabled := true;  //make copy inside timer event?

procedure TfrmMain.miCopyPosClick(Sender : TObject);
  SaveRectCoords; //Saving rect coordinates to clipboard (OK)

procedure TfrmMain.timCopyImgTimer(Sender : TObject);
  timCopyImg.Enabled := false;
  miCopyImage.Visible := false; //Does not work, caption still present
  self.Refresh;  //Does also not work to remove caption
  miCopyImage.Visible := true;  //Put it back to enable next capture

procedure TfrmMain.CopyScreenRect;
  MyCapture : TBgraBitmap;
  Clip: TRect;
    Clip := Bounds(Self.Left, Self.Top, Self.Width, Self.Height);
    Self.Visible := false; //Hide selection form before copy
    //Self.Hide;  //Not working for popup menu item...
    MyCapture := TBgraBitmap.Create();
    Self.Visible := true; //Show selection form after copy is done
    //Self.Show;  //Not working for popup menu item...
    on E: exception do
      Clipboard.AsText := E.Message;

Even Self.Visible or Self.Hide do not remove the menuitem caption....

What can I do?

Lazarus 2.0.10 / fpc 3.2.0 on Windows 10

Bo Berglund
Developer in Sweden

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