876323 - nsSVGTextFrame2 should avoid recomputing mPositions when COORD_CONTEXT_CHANGED unless percentages were used

Status: RESOLVED FIXED

(Core :: SVG, defect)

Description

[Cameron McCormack (:heycam)]

When nsSVGTextFrame2::NotifySVGChanged is called with COORD_CONTEXT_CHANGED, we can avoid calling NotifyGlyphMetricsChange unless we actually did use percentage values in the text positioning attributes.

Comment 1

[Cameron McCormack (:heycam)]

Attachment: test

For example you wouldn't expect this to need to call DoGlyphPositioning on each resize.

Comment 2

[Cameron McCormack (:heycam)]

Attachment: patch

Comment 3

[Robert Longson [:longsonr]]

Should use a frame state bit for the flag (as well as mPositioningDirty)

Comment 4

[Cameron McCormack (:heycam)]

There's bug 865901 for mPositioningDirty.  How about we do them both at once over there.  (We're at least not increasing the size of the frame object by adding this second one.)

Comment 5

[Jonathan Watt [:jwatt]]

Comment on attachment 754330 [details] [diff] [review]
patch

Nice.

Regarding "mPositioningUsesPercentages", I think you should put the word "may" in there so that it's clear to readers that it's not a certainty even without reading the doc comment.

Other than that, can you add a reftest along the lines of layout/reftests/svg/stroke-width-percentage-03.xhtml where we check that things work when the content window changes size? (Changing the width/height attributes on an <svg> will cause reflow that may mask bugs with content area resizing which won't necessarily cause reflow.)

Given the "Percentage values beyond the number of addressable characters, however, do not influence mPositioningUsesPercentages" comment, it would also be good to have similar tests that add text after MozReftestInvalidate making an "out of bounds percentage" have something to apply to, and make sure that works.

Comment 6

[Cameron McCormack (:heycam)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/cc20743e8fe9

Comment 7

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/cc20743e8fe9