1753814 - Add an option to configure the maximum amount of pinch zoom that is available

Status: RESOLVED FIXED

(Core :: Panning and Zooming, enhancement, P3)

Description

[Peter Bašista]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:96.0) Gecko/20100101 Firefox/96.0

Steps to reproduce:

Use the pinch zoom feature.

Actual results:

The page is zoomed. But only to a maximum amount that is hardcoded.

Expected results:

The page should be zoomed in the same way as it is now. But the maximum amount of pinch zoom that is available should be configurable by user.

Comment 1

[Botond Ballo [:botond]]

Thanks for filing.

I'm going to mark this as a mentored bug, it's a nice simple change for someone looking to start contributing to the Firefox codebase.

Comment 2

[Matteo Ruello]

Do I understand correctly that we still want to limit the zoom, but we want users to configure kViewportMaxScale ? This number is then multiplied by other factors to actually compute the maxZoom factor.

Comment 3

[Botond Ballo [:botond]]

(In reply to Matteo Ruello from comment #2)

Do I understand correctly that we still want to limit the zoom, but we want users to configure kViewportMaxScale ? This number is then multiplied by other factors to actually compute the maxZoom factor.

Yup, that's right. I do think the browser should still enforce a (less strict) hardcoded limit, e.g. for zooming out you should be able to change the minimum zoom to be lower than the default minimum of 0.25, but we should still clamp it to some smaller threshold (e.g. 0.1). Otherwise, if we allow the user to reach an extreme value (say, 0.001), on a sufficiently large page the browser's going to run into stability issues (e.g. trying to rasterize a huge number of text glyphs and running out of memory or something like that).

The preferences can be defined in StaticPrefList.yaml, with names such as apz.min_zoom and apz.max_zoom. In the code, they'll then be accessible as StaticPrefs::apz_min_zoom() etc.

Comment 4

[Botond Ballo [:botond]]

Assigning to Matteo who is interested in working on this.

Comment 5

[Matteo Ruello]

Attachment: WIP: Bug 1753814 max/minZoom are now configurable through prefs

Comment 6

[Botond Ballo [:botond]]

Hi Matteo, I was wondering if you're interested in continuing to work on this? If not, we have another contribution who may be interested in picking it up.

Comment 7

[BugBot [:suhaib / :marco/ :calixte]]

The bug assignee is inactive on Bugzilla, so the assignee is being reset.

Comment 8

[Razvan Cojocaru]

Attachment: Bug 1753814 - Add an option to configure the maximum amount of pinch zoom that is available. r?dlrobertson

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/2e4152e77b7b
Add an option to configure the maximum amount of pinch zoom that is available. r=dlrobertson

Comment 10

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/2e4152e77b7b