Add a space between the menu and the caption

[trmdi]

Current:

Expect:

When there is not enough space, the caption should be hidden or something like that, but there should be always a space between them.

[Zren]

I originally was planning to have a gradient fadeaway when the menu covered it, then I found outthe existing code can center the caption if not covered, or draw in the remaining space when the center position is overlapped.

I should probably get rid of the gradient, and center it in the remaining space. It already doesn't draw the caption when the menu is overflowing.

[trmdi]

Yes, but in some case centering it may be not enough e.g. when the remaining space == the caption's length.

[trmdi]

Maybe we should always center it in the whole length of the titlebar (not the remaining space) AND only show it if the space between the menu and the caption >= some minimum value ?

[trmdi]

A video about the behavior of Unity's LIM: https://youtu.be/nzFXRz-b3Ns?t=40

[ripefig]

Yeah, with the Unity implementaton all the problems go away.

[Zren]

Yep Unity's "drag even app buttons" is requested in Issue #2.