[issue20917] Idle: Enhance font change notification system

Change by Cheryl Sabella : -- dependencies: +IDLE: Add docstrings and tests for codecontext versions: +Python 3.8 -Python 3.6 ___ Python tracker ___

[issue20917] Idle: Enhance font change notification system

Terry J. Reedy added the comment: I believe I saw somewhere that the 'somehow' in the opening post is looping through the windows listed under the Window tab. This issue was inspired by #17642, which allows hotkeys (^-, ^+) and wheel to change font size in editor window. If the size change on

[issue20917] Idle: Enhance font change notification system

Changes by Terry J. Reedy : -- assignee: -> terry.reedy components: +IDLE stage: -> test needed versions: +Python 3.6, Python 3.7 -Python 2.7, Python 3.3, Python 3.4 ___ Python tracker ___

[issue20917] Idle: Enhance font change notification system

Mark Roseman added the comment: The new 'component' infrastructure provides the mechanism for passing these kinds of notifications around. Allowing extensions (in whatever form they'll exist with the new stuff) to take part in this notification mechanism would be a small (and sensible) additi

[issue20917] Idle: Enhance font change notification system

Terry J. Reedy added the comment: Changing CodeContext.py to drop the font polling and use the new mechanism is part of this issue. Such a change would effectively be part of its test. -- ___ Python tracker __

[issue20917] Idle: Enhance font change notification system

New submission from Terry J. Reedy: If one changes the font in the Idle Preferences dialog, all open windows are somehow notified and they immediately respond. Classes defined in extensions do not get notified. So CodeContext sets up a polling loop. Roger Serwy's line number extension (posted