Implement robust minimum pane size

[tim-blackbird]

We need a robust pane resizing implementation that prevents panes from being resized below a minimum size.

The minimum size along the height should be the height of the panel header.
I'm don't see an obvious choice for the minimum width. I'd pick the panel header height as minimum here as well for now.

Keep in mind that this also needs to prevent the panes going below the limit when the entire window is being resized.

[n1ght-hunter]

shouldn't the minimum size be based on the content?

[tim-blackbird]

Currently not planned, for the sake of flexibility and user-control of the layout.
I'd say the current trajectory for the prototype is somewhat like blender where toolbars and related menus are embedded within the pane rather than being separate like in Maya.

But of course my opinion isn't everything. Please do share your thoughts :)

[n1ght-hunter]

oh maybe i misunderstood a little.
i think each pane should have a min size associated with it i.e.

struct SomePane {
    min_height: f32,
    min_width: f32,
   ... other things
}