How do I use functions named GUI_Disp... and GUI_Draw... for drawing on a widget?

shinec712 · November 21, 2023 at 4:58 AM

Do I have to use a text widget on top of the image widget to draw text?

is there another way??

SEGGER - Florian · November 22, 2023 at 9:16 AM

Hi,

The easiest way would indeed be to place a TEXT widget on top of the IMAGE widget.

The other way would be to call the GUI_Disp... routine within a callback when reacting on a WM_PAINT message. So you would manually handle the drawing of the widget.

In your case you would set a custom callback to the IMAGE widget and call your drawing function after calling the default IMAGE callback to ensure that the image is still drawn normally.

C

case WM_PAINT:
  //
  // Call standard IMAGE callback so that the image is still displayed.
  //
  IMAGE_Callback(pMsg);
  //
  // Display something on top...
  //
  GUI_Disp...
  break;

In our wiki you can find a simple example on how to set a custom callback to a widget.

Best regards,
Florian

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