Show status text for screenshots in the main menu

[siliconsniffer]

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Note

I used an LLM Chatbot/Assistant during development, but I take full responsibility for the submitted changes.

This is a follow-up PR of #16749.

• Goal of the PR
  Display status messages in the main menu.
• How does the PR work?
  Implements a new GUI component GUIStatusText for displaying temporary status messages.
• Does it resolve any reported issue?
  Closes [Formspec] Status messages in the main menu (e.g. for screenshots) #16759
• Does this relate to a goal in the roadmap?
  Not directly, as far as I can tell.
• If not a bug fix, why is this PR needed? What usecases does it solve?
  It hints to the user that a screenshot has been made.

To do

This PR is ready for review.

• Styling of the status message?
• Test on Android.

How to test

open luanti → press F12 / screenshot keybind → observe that a status message appears and fades out again

Preview

[sfan5]

Styling of the status message?

I think the black background is unnecessary.

[CrazyladMT]

I think the black background is unnecessary.

I think it looks fine. Without it, the text would be unreadable on the eye cancer shade of blue used for the menu background.

[siliconsniffer]

I think the black background is unnecessary.

I disagree. On a smaller screen, the text will overlap with the gamebar and will be hardly readable.

For comparison, here it is with the background.

[siliconsniffer]

It does work on Android, but while testing I noticed two things:

• the long path renders the status message practically worthless
• in contrast to the opaque background shown above, it is transparent

[Zughy]

Wait, why do you need to notice players on Android? Doesn't the OS already play an animation on its own when taking a screenshot?

[sfan5]

Wait, why do you need to notice players on Android? Doesn't the OS already play an animation on its own when taking a screenshot?

This is about the F12 screenshot function in Luanti. This is not even accessible on Android unless you have a keyboard connected.

[siliconsniffer]

A slightly simpler design: