596969 - Viewport is resized when switching tabs

Status: VERIFIED FIXED

(Firefox for Android Graveyard :: General, defect)

Description

[Matt Brubeck (:mbrubeck)]

Steps to reproduce:
1. Open a page with non-default viewport width, e.g. http://touch.facebook.com
2. Switch to a different tab, then back to the first tab

Expected results: Page layout remains the same
Actual results: Viewport width changes

This is a regression from bug 576192.

Comment 1

[Matt Brubeck (:mbrubeck)]

This seems to (maybe?) happen as a result of nsFrameLoader::ShowRemoteFrame calling GetSubDocumentSize and then TabParent::Move - the dimensions passed to Move do not match the explicit viewport metadata.

Comment 2

[Matt Brubeck (:mbrubeck)]

This might be helped by the new API proposed in bug 589337 to replace Show/Hide for switching tabs.

Comment 3

[Matt Brubeck (:mbrubeck)]

We'd like to change the platform to *not* change the CSS viewport size on window/widget resize, if an override has been set using nsIDOMWindowUtils.setCSSViewport.

Comment 4

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

Attachment: Allow a document's CSS viewport to be permanently overridden by chrome script

To be clear, the fennec frontend wants to use this feature to implement the <meta viewport> tag available to web content, in such a way that the frontend doesn't have to always listen for resizes (e.g. on device orientation change) and reset them back to the <meta viewport>.  That's a bit tricky and can be expensive if we don't prevent the reflow in time.

Comment 5

[Matt Brubeck (:mbrubeck)]

How should we call ResizeReflowOverride from the frontend?  Should nsDOMWindowUtils::SetCSSViewport call it for us (maybe optionally)?

Comment 6

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

Attachment: Allow a document's CSS viewport to be permanently overridden by chrome script, v2

Thanks Matt!  I didn't change the nsDOMWindowUtils callsite, and my test was wrong.

Comment 7

[Matt Brubeck (:mbrubeck)]

This is working great, but it seems to make bug 597230 happen more often.  Working on a patch in that bug.

Comment 8

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

Comment on attachment 477787 [details] [diff] [review]
Allow a document's CSS viewport to be permanently overridden by chrome script, v2

sr=dbaron

Comment 9

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

http://hg.mozilla.org/mozilla-central/rev/1c33f957836a

Comment 10

[Aakash Desai [:aakashd]]

verified FIXED on builds:
Mozilla/5.0 (Maemo; Linux armv71; rv:2.0b6pre) Gecko/20100927 Namoroka/4.0b7pre Fennec/2.0b1pre

and

Mozilla/5.0 (Android; Linux armv71; rv:2.0b6pre) Gecko/20100927 Namoroka/4.0b7pre Fennec/2.0b1pre