BUG: 377562
KTextEditor::KateViewInternal::wheelEvent() implements text zoom in reaction to Ctrl+Wheel events, something Qt also implements or used to implement for QTextEdit and/or QTextBrowser.
Problems can occur with systems with a trackpad that use 2-finger scrolling and scroll inertia. These are subject to unexpected, accidental text zooming when the user holds presses the Ctrl key to trigger a shortcut (say, Ctrl-S to save the current document) before scroll coasting has stopped completely.
The end of coasting isn't always clear: scroll events may continue to come in with sub-threshold deltas, or when the view has already reached its extreme position and can scroll no further. This affects me much more frequently than I would like in applications like KDevelop and is especially annoying since there is no standard shortcut to return to 100% (no zoom).
Qt itself has a form of protection against this kind of annoyance on Mac and possibly other systems where inertial scrolling has better platform support than under X11.
This patch provides what I hope is a reasonably minimal implementation of a similar protection that ignores Control modifier changes that occur within a certain lapse of time after the start of a series of wheel events.