Limit interface scale

[AlbyIanna]

Motivation

The interface scaling of the IDE doesn't handle scaling properly:

• as stated in Application allows setting interface scaling interface past limits #1384, it's possible to find yourself in unpredictable situations we're only limiting the scaling when using the stepper input
• same thing happen with the editor font size
• when changing the scaling really fast (e.g.: holding down CTRL/CMD + = for a while), the interface seems to 'bounce' from bigger to smaller and viceversa until it's stable

Change description

• move the interface scaling logic to a separate contribution
• the stepper in the settings dialog and the related commands now uses common values for min/max scale and font size
• when the Automatic flag in the settings dialog is checked, enable/disable the 'Increase/Decrease Font Size' menu item and shortcuts when reaching -60% (min) and 280% (max)
• when the Automatic flag in the settings dialog is unchecked, enable/disable the 'Increase/Decrease Font Size' menu item and shortcuts when reaching 8 (min) and 72 (max)

Other information

Since Theia doesn't support dynamic menu items, to achieve this I needed to dispose the menu items and re-register them, and then update the mainMenuManager manually, otherwise they wouldn't get updated as expected.

Reviewer checklist

• PR addresses a single concern.
• The PR has no duplicates (please search among the Pull Requests before creating one)
• PR title and description are properly filled.
• Docs have been added / updated (for bug fixes / features)

[kittaakos]

Do you plan to get rid of the local settings field? Is this PR still in progress? See here: #1502 (comment).

[AlbyIanna]

Do you plan to get rid of the local settings field? Is this PR still in progress? See here: #1502 (comment).

@kittaakos I've already got rid of currentScale because it wasn't necessary (see last commit). About currentSettings – as stated in this comment → #1502 (comment) – I can't remove it because it's not only a duplicate but it also serves as temporary value in order to make the debouncing work correctly (see how I update the settings here)

[kittaakos]

Thank you! I checked the code and left a few remarks.

[kittaakos]

I have noticed some inconsistency between the disabled/enabled state of the menu item and the current editor.fontSize value.

Decrease expected to be disabled here:

Increase expected to be disabled here:

Decrease expected to be enabled here:

[AlbyIanna]

I have noticed some inconsistency between the disabled/enabled state of the menu item and the current editor.fontSize value.

Thank you @kittaakos, I wasn't registering the menus properly after changing fontScalingEnabled. Fixed in this commit.

I also the menu items weren't updating when changing the autoScaleInterface setting, so I also fixed that in the last commit

[per1234]

I verified it fixes #1384

Thanks Alberto!

[kittaakos]

It's working great. Thank you!