Fix aspect ratio in selection widget when pressing CTRL

[ElTh0r0]

Another approach to fix aspect ratio in selection widget when pressing CTRL (fix for #3436).

This PR gets the aspect ratio only once when the left mouse button is pressed. Before, the aspect ratio was permanently calculated while the mouse was moved, but QWidget:geometry only returns a QRect with integer precision, so we constantly lost aspect ratio precision while the mouse was moved.

There is another old PR #3439, which was never finalized. It may be closed if this one is merged.

[mmahmoudian]

Nice fix. Also great to catch the division by zero. I initially didn't think about that.

As a general comment and not specific to this PR, I was puzzled why even changing the variable name and prepend m_. I think in general we need some more commenting in the codebase to explain some of these naming conventions.

[ElTh0r0]

Thank you for the review!

As a general comment and not specific to this PR, I was puzzled why even changing the variable name and prepend m_. I think in general we need some more commenting in the codebase to explain some of these naming conventions.

I moved the aspect ratio from a local function variable to a class member variable. The m_ prefix is a common naming convention in C++ projects and most / all (?) Flameshot classes are using this convention, so I added the prefix too, even if this rule is not written anywhere.
I am open for a separate discussion about this topic!

[andrewanswer]

ElTh0r0 Thank you for this patch, waiting for releasing that!

[ElTh0r0]

Hi @borgmanJeremy
once you have time, please review if this fix can be merged 😊

[borgmanJeremy]

Thanks for the ping! Lost track of this one.