Add zoom command.

[smblott-github]

Examples:

map = zoom in factor=1.1
map - zoom in factor=1.1

map = zoom factor=1.1
map - zoom factor=0.90909

Fixes #1866.

[ghost]

Please merge 😻

[NightMachinery]

Please merge.

[maxim-danilov]

It's a very useful feature. I use zooming on every site. Please add support:

map q zoomIn
map w zoomOut

Or just merge the commit.

[Monirzadeh]

please merge

[alfozan]

+1

[philc]

@smblott-github we used to have a zoom command in the early days of Vimium. Here's the initial commit (d367e58). We even saved the preference per domain, and had a configurable default zoom level (6042b7f) in Vimium.

I removed (dc114c1) this command because setting document.body.style.zoom doesn't work the same as whatever Chrome is doing when you use Chrome's native zoom. In particular, text would start unexpectedly wrapping on some pages based on the zoom level, which never happens with Chrome's native zoom.

See git log --grep=zoom for all related commits and for some of the complexity this feature caused.

If we rework this to use Chrome's native zoom API rather than document.body.style.zoom, that should solve the zoom robustness piece.

To make this feature more robust, we could then add:

1. Remembering the setting for the given domain as Chrome does (assuming use of the zoom settings API doesn't already do that by default; requires further investigation).
2. Implement a default zoom level setting, as Chrome has. That way, we will start zooming or unzooming from the user's default, rather than from 100%. For my use case, I wanted every page to be zoomed to 120% by default, and wanted a command to increase or decrease it from there. Chrome's default functionality implements this well.

I would argue that this command is not acceptable without adding #1, because our zoom is inferior to Chrome's native zoom in a really annoying way (i.e. it has a hidden sharp edge). I could see people navigating to reddit.com, zooming in, and the next time they navigate there, zooming in again because their settings weren't saved, and doing that every time they load the page. With Chrome's native zoom functionality, they would only have to zoom once.

EDIT: fixed commit IDs.

[j-cr]

Saka key has this feature:
https://github.com/lusakasa/saka-key/blob/3ec7984c1a1d630f6c1eb5b9a6932678cf6a21a3/src/modes/command/background/commands/tab.js#L161

const zoomStep = 10 // for 10%

/** Zoom in the active tab of the current window */
export async function zoomIn () {
  const [tab] = await browser.tabs.query({ currentWindow: true, active: true })
  const zoomFactor = await browser.tabs.getZoom()
  await browser.tabs.setZoom(tab.id, Math.min(zoomFactor + zoomStep / 100, 3.0))
}

/** Zoom out the active tab of the current window */
export async function zoomOut () {
  const [tab] = await browser.tabs.query({ currentWindow: true, active: true })
  const zoomFactor = await browser.tabs.getZoom()
  await browser.tabs.setZoom(tab.id, Math.max(zoomFactor - zoomStep / 100, 0.3))
}

/** Reset the zoom of the active tab of the current window */
export async function zoomReset () {
  const [tab] = await browser.tabs.query({ currentWindow: true, active: true })
  await browser.tabs.setZoom(tab.id, 0)
}

Seems straightforward?

(1) and (2) from the comment above already work as expected in saka key.

EDIT: reopen #1866 since this PR is in coffeescript?

[philc]

Closing this PR because it's outdated, but I've reopened #1866 to track the feature request.