Support variable line heights in the editor

[hediet]

This would allow to use larger font sizes for markdown headers.

[usernamehw]

@hediet Is this issue for TextMate grammar or editor decorations or both?

Grammar makes sense for markdown headers but editor decorations would be great too. For example, adding an image decoration (bigger than one line) without a webview (like code inset #85682).

[hediet]

It is not clear yet what mechanism will be used for that.

How would you add that image if you could set the line height? By using css?

[usernamehw]

It's already supported, the image is just very small (1 line).

In decoration options after.contentIconPath

---

Hmmm, actually it renders the full image ignoring width & height

window.activeTextEditor?.setDecorations(window.createTextEditorDecorationType({
	after: {
		contentIconPath: Uri.parse('https://random.imagecdn.app/500/150'),
		margin: '0 20ch',
		height: '2ch',
		width: '2ch',
	},
}), [new Range(0, 0, 0, 0)]);

[yume-chan]

Another use case would be shrinking empty lines #66468

Visual Studio has an extension (by Microsoft) to do that. https://marketplace.visualstudio.com/items?itemName=VisualStudioPlatformTeam.SyntacticLineCompression2022

[folcik]

+1 on this
Decorations can already modify the font size/font family/line height of a portion of text, but none of those changes render properly without the line height being variable.
Use cases for this include:

• Different font (size/family/height) for keywords or for searched text
• Inline markdown editor/viewer
• Inline images or icons
• Increasing or reducing the size of font/lines that may be irrelevant (say, big function header comments can be slightly smaller if you want them to be less distracting, or TODO items could be larger or more apparent)
• Could allow some very clever community extensions for "rich" editing (I understand this is not intended to be a rich text editor, but it is very close to being able to be one)

[MrScottyTay]

+1 Trying to migrate over to VS Code and the shrink empty lines extension for Visual Studio was amazing