User Interface: Zoom In / Out Using Keyboard / Pen

[ghost]

Zoom In / Out Using The Keyboard/Pen

ALT- Pen already 'pans' across the board, so that is good, but the Zoom needs to be consistent with using the pen and keyboard as well, and could mimic other software interfaces that users are already familiar with and expecting to work the same way.

Photoshop, Krita, Affinity Designer:
Spacebar-Down = Pan image
Ctl - Spacebar + PenDown + Up/Down Movement = Zoom In / Out

Pretty sure this is common for many other applications, with some variation.

Note: I don't consider this an enhancement, but a basic UI interface requirement :D

[mbrlabs]

This is already implemented in the main branch (but not available in the latest release). See: #71