[cairo] erasing overlay on GTK drawing area widget.

Michael K vk2bea at yahoo.com
Wed Mar 30 15:33:04 UTC 2022


 Well, I'll ask the question in a cairo only way then...
Can I overlay text onto a cairo surface and then erase the text without destroying the image below?Could I, for example, copy/cache the rectangle under the text  before writing (using extents to determine the dimensions) so that I could later use that to effectively restore the underlying image before writing new text.Is there a better / simpler way to do this?
thanks
    On Wednesday, March 30, 2022, 08:18:10 AM EDT, Emmanuele Bassi <ebassi at gmail.com> wrote:  
 
 Hi;
if you have questions about GTK, you should use the GNOME Discourse:
https://discourse.gnome.org/tag/gtk
Ciao, Emmanuele.

On Tue, 29 Mar 2022 at 16:45, Michael K <vk2bea at yahoo.com> wrote:

I'm attempting to have two GtkDrawingArea widgets in a GtkOverlay container.
The lower widget is a graph and the top widget shows dynamically changing information related to the graph based on the mouse position.
I cannot seem to erase the top drawing area without wiping out the graph on the bottom drawing area.
Is this at all possible or am I just doing something wrong ?


-- 
https://www.bassi.io
[@] ebassi [@gmail.com]  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cairographics.org/archives/cairo/attachments/20220330/8de22ac3/attachment.htm>


More information about the cairo mailing list