Change: Disable NewGRF window apply button if no change was made

[perezdidac]

Motivation / Problem

The NewGRF window has a 'Apply changes' button that's always enabled, even if the user has not made any change to the NewGRF. In addition, closing the NewGRF window without having made any change executes the reload of NewGRF which can take some time.

Description

This change makes the 'Apply changes' button to be disabled (grayed out) by default until changes are made, including loading a preset, dragging/dropping from/to the inactive NewGRFs list, clicking on the 'Add' or 'Remove' button, toggling the palette, and opening the parameters window. I believe with this all changes are covered. I have also verified with the scenario editor, where NewGRFs cannot be modified by default unless the hidden developer option is changed in the configuration file.

Limitations

None I can think of.

Checklist for review

Some things are not automated, and forgotten often. This list is a reminder for the reviewers.

• The bug fix is important enough to be backported? (label: 'backport requested')
• This PR affects the save game format? (label 'savegame upgrade')
• This PR affects the GS/AI API? (label 'needs review: Script API')
  • ai_changelog.hpp, gs_changelog.hpp need updating.
  • The compatibility wrappers (compat_*.nut) need updating.
• This PR affects the NewGRF API? (label 'needs review: NewGRF')
  • newgrf_debug_data.h may need updating.
  • PR must be added to API tracker

[LordAro]

The NewGRF window is (along with a lot of the other new game menus) is going to be rewritten for 1.12, so I'm tempted to close this as it's not a change that will ever see a release... (happy for other opinions)

[perezdidac]

The NewGRF window is (along with a lot of the other new game menus) is going to be rewritten for 1.12, so I'm tempted to close this as it's not a change that will ever see a release... (happy for other opinions)

Good to know, is there a wiki or documentation about the plans? I don't want to work on things that will be re-written :)
Submitting this will benefit patches like JGRPP though, and making sure the next design adheres to the right UX principles.

[perezdidac]

Thanks @michicc for the comments, I just made simplifications and looks pretty cleaner now.

[michicc]

Found a missed variant: Moving a NewGRF in the active list up or down does not enable the apply button.

[perezdidac]

Found a missed variant: Moving a NewGRF in the active list up or down does not enable the apply button.

Wohaa! Good catch! I can't believe I missed that, well that's awesome, let me fix that and force push the new code.