Painter example Undo/Ctrl-Z

by Martin Fitzpatrick Last updated PyQt5 FAQ
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Paapu | 2020-05-10 20:21:13 UTC | #1

I tried to figure out how to cancel a part of a drawing (using subsequent ctrl-Z or something). Would this be doable? (I could not make it...)

martin | 2020-05-10 20:22:07 UTC | #2

Hi @Paapu it should be! One simple way would be to take a snapshot of the current pixmap canvas on every mouse down (start drawing) and store this in a temporary variable. Then when Ctrl-Z is pressed (detected using a QAction) you can copy that back over the current canvas.

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Martin Fitzpatrick

Painter example Undo/Ctrl-Z was written by Martin Fitzpatrick.

Martin Fitzpatrick has been developing Python/Qt apps for 8 years. Building desktop applications to make data-analysis tools more user-friendly, Python was the obvious choice. Starting with Tk, later moving to wxWidgets and finally adopting PyQt. Martin founded PythonGUIs to provide easy to follow GUI programming tutorials to the Python community. He has written a number of popular Python books on the subject.

Painter example Undo/Ctrl-Z was published in faq on (updated ) . Feedback & Corrections can be submitted here.

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