Bug 483946

SUMMARY
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The usability of the image preview needs to be improved. The most frequent use case is viewing photos with mouse alone. The zoom should be controllable with just the mouse scroll wheel without pressing the Ctrl key. 
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STEPS TO REPRODUCE
1. Switch to Preview mode by double clicking an image
2. Try to zoom into the image by rolling just the scroll wheel on the mouse. Do not press the control key

OBSERVED RESULT
Nothing happens, if the image does not fit inside the viewer window then the image scrolls vertically 

EXPECTED RESULT
The image should zoom using just the scroll wheel.

REASONING
1. Every single image viewer by convention uses the scroll wheel to zoom the image without pressing any other modifier keys. The behavior should be made consistent with what users expect from other apps
2. The default behavior of scrolling the image when it's already zoomed in is a document convention , not an image convention
3. The current behavior of scrolling the image when the mouse wheel is used is not really useful for 3 reasons
   a. the wheel does nothing if the image is sized to or smaller than the preview window
   b. The scroll wheel only scrolls the zoomed in image vertically, not horizontally
   c. If one is already using a mouse. It's a much user friendly experience to drag the zoomed in image in both axes simultaneously (as done by all other imaging apps) rather than scrolling the image vertically


SOFTWARE/OS VERSIONS
Linux: Linux Mint 21.2 Cinnamon