Bug 84456 – [Qt] Multi-level tap-to-zoom

• Status: RESOLVED
• Resolution: FIXED
• Component: WebKit2

[Allan Sandfeld Jensen]

The current zoom-out feature of tap-to-zoom makes it impossible to zoom in to progressively smaller areas.

We need a way to both allow refining zoom and detecting zoom-out gesture.

[Allan Sandfeld Jensen]

Created attachment 138101 [details]
Patch

[Kenneth Rohde Christiansen]

Comment on attachment 138101 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=138101&action=review

> Source/WebKit2/ChangeLog:12
> +        Replace tap-to-zoomed flag with a stack of progressively higher zoom levels, 
> +        and zoom out to last zoom-level when attempting to zoom to current level.
> +        
> +        Additionally detect a series of tap-to-zoom gestures on the same level and 
> +        continue to zoom out.

I wonder how well this works in practise... let\s see

> Source/WebKit2/UIProcess/qt/QtViewportInteractionEngine.cpp:373
> +        // Zoom back out if attempting to scale to the same current scale, or
> +        // attempting to continue scaling out from the inner most level.

This is not exactly what we want, it depends on whether we have a position change (larger/smaller than a treshold) as well. It is kind of common to scroll on ios by double tapping when zoomed in, as it will scroll and be perfectly aligned

[Allan Sandfeld Jensen]

(In reply to comment #2)
> (From update of attachment 138101 [details])
> View in context: https://bugs.webkit.org/attachment.cgi?id=138101&action=review
> 
> > Source/WebKit2/ChangeLog:12
> > +        Replace tap-to-zoomed flag with a stack of progressively higher zoom levels, 
> > +        and zoom out to last zoom-level when attempting to zoom to current level.
> > +        
> > +        Additionally detect a series of tap-to-zoom gestures on the same level and 
> > +        continue to zoom out.
> 
> I wonder how well this works in practise... let\s see
> 
> > Source/WebKit2/UIProcess/qt/QtViewportInteractionEngine.cpp:373
> > +        // Zoom back out if attempting to scale to the same current scale, or
> > +        // attempting to continue scaling out from the inner most level.
> 
> This is not exactly what we want, it depends on whether we have a position change (larger/smaller than a treshold) as well. It is kind of common to scroll on ios by double tapping when zoomed in, as it will scroll and be perfectly aligned

Yeah, I am getting to that part :) I am just adding one feature at a time and making sure it works. 

This patch is intended to be a similar but improved version of what we do on the N9.

Next up is checking if the double-click should move instead of zooming, but if possible I would like to handle that in a separate bug.

[WebKit Review Bot]

Comment on attachment 138101 [details]
Patch

Clearing flags on attachment: 138101

Committed r114857: <http://trac.webkit.org/changeset/114857>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.