45 Move the view of the viewbox to a given position

[mariehartung]

resolves #45

This draft PR will be transformed into a full pull request as soon as issue 10 is merged into main. Therefore, this can already be reviewed.

View of the viewbox can be moved using normalized coordinates

The following changes were implemented in the class MainW in cellpose/gui/gui.py:

• method center_view_on_position was created
• method takes normalized coordinates as input
• height and width of image are extracted using self.img.image.shape and used to calculate new positions
• current zoom is calculated using view-range self.p0.viewRange(): used to calculate width and height of view range to maintain zoom level
• new view range with given coordinates as center is calculated and implemented

Information for testing

This issue is part of the former ticket 13. The extraction of the coordinates will be implemented in ticket 44. Ticket 46 will combine the two features.
For testing the functionality of this implementation, I recommend calling the function using self.center_view_on_position(0.5, 0.5) in the method minimap_window in gui.py.
The parameters 0.5, 0.5 refer to normalized x- and y-coordinates; this will put the center of the current image at the center of the view box. When using the minimap_window method, the minimap button in the menu will have to be (un)toggled to call this method.
I suggest trying out different values (between 0 and 1) as well as different zoom levels.

Showcase

Zoom
For a picture zoomed out, this should look (when using 0.5, 0.5) similar to this:

And for a picture zoomed in, similar to this:

Coordinates
When using different values than 0.5, 0.5, other parts of the picture should be at the center:
E.g. for 0,0, the upper left corner should be at the center:

[RukiyyeE]

It looks good! I tested the function as described with different coordinates in minimap_window, and the images are centered as expected. The code is well documented and structured. Running Cellpose does not produce any error messages, and the code does not cause any issues. I don't have any suggestions for changes anymore and would therefore approve it. Great job :)

The merge-base changed after approval.

The merge-base changed after approval.

[NicolasDelgadoL]

Great job! The code has a very clear structure and is well commented, it reflects how the problem was broken down into smaller steps and makes it easy to understand whats happening. I also didn't encounter any bugs or errors while testing and would approve 👍