feat: add hover effects to divider in ResizablePaneManager

[Haz3-jolt]

Purpose / Description

• Resizable divider onHover changes PointerIcon to a resizing indicator and sets divider to dragColor

Fixes

• For GSoC 2025: Tablet & Chromebook UI

Approach

• As suggested by @SanjaySargam this will add a onHoverListner to the ResizablePaneManager to show users that it is resizable

How Has This Been Tested?

Tested on Chromebook emulator - API 34
hover.webm

Checklist

• You have a descriptive commit message with a short title (first line, max 50 chars).
• You have commented your code, particularly in hard-to-understand areas
• You have performed a self-review of your own code
• UI changes: include screenshots of all affected screens (in particular showing any new or changed strings)
• UI Changes: You have tested your change using the Google Accessibility Scanner

[david-allison]

Could you make the color change much more subtle (probably to another gray)

It's a jarring color transition right now for a hover effect

[Haz3-jolt]

Could you make the color change much more subtle (probably to another gray)

It's a jarring color transition right now for a hover effect

I chose this because it's the norm for resizing screens on desktop sites:

colors.mp4

[david-allison]

Ok, the video works.

Have the area which changes color match the width of the area in the video you provided.

[SanjaySargam]

duplicates some color-setting behavior from touch events - consider extracting common visual state methods

Something like this:

private fun setDividerVisualState(view: View, backgroundColor: Int, pointerIcon: PointerIcon?) {
              view.setBackgroundColor(backgroundColor)
              view.pointerIcon = pointerIcon
      }

[Haz3-jolt]

Ok, the video works.

Have the area which changes color match the width of the area in the video you provided.

Wait so I should reduce the width of the divider? because all it is doing is changing it's background color.

[david-allison]

• add an issue so we can deal with this later, no hover colour is better than a bad hoover colour
• Keep the pointer effect, we can get this PR in now
• Consider moving the Frame Layout + View to a custom view, so we can better handle onDraw

[Haz3-jolt]

• add an issue so we can deal with this later, no hover colour is better than a bad hoover colour

  • Keep the pointer effect, we can get this PR in now

  • Consider moving the Frame Layout + View to a custom view, so we can better handle onDraw

I'll update it tomorrow!

[SanjaySargam]

LGTM 🚀