Replace some obsolete methods with non-obsolete ones
Summary:
There are some deprecated methods in the code:
Test Plan:
- Run Gwenview, select an image.
- Use Edit -> Crop to ensure that cropping is working as expected.
- Press F11 to go to the full screen mode. The top panel should appear as expected.
Reviewers: Gwenview, ngraham
Reviewed By: Gwenview, ngraham
Subscribers: meven, ngraham, tommo
Tags: Gwenview
Differential Revision: https://phabricator.kde.org/D22527