void ctx.clearHitRegions() was added to canvas in https://html5.org/r/8747 "When the clearHitRegions() method is invoked, the user agent must remove all the hit regions from the rendering context's scratch bitmap's hit region list." MDN https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D.clearHitRegions

I usually only document and not implement features, but I thought I give this a shot. Feel free to tweak as needed or let me know what to do here.

Comment on attachment 8546293 [details] [diff] [review] bug1119527.patch Review of attachment 8546293 [details] [diff] [review]: ----------------------------------------------------------------- Drive by feedback... ::: dom/canvas/CanvasRenderingContext2D.cpp @@ +3232,5 @@ > > +void > +CanvasRenderingContext2D::ClearHitRegions() > +{ > + mHitRegionsOptions.ClearAndRetainStorage(); Why not just Clear()? ::: dom/canvas/test/test_hitregion_canvas.html @@ +39,5 @@ > ctx.removeHitRegion("b"); > + > + ctx.addHitRegion("x"); > + ctx.addHitRegion("y"); > + ctx.clearHitRegions(); I don't think there are regions x and y - I'd just add clearHitRegions() after all the removes - to test if clear works properly when there are no regions, but also copy the whole try{} and do clear instead of the three removes, to test the clear when there are valid regions around.

(In reply to Milan Sreckovic [:milan] from comment #3) > > + mHitRegionsOptions.ClearAndRetainStorage(); > > Why not just Clear()? > No idea, I found that in CanvasRenderingContext2D::Reset() and thought it would do the right thing. https://dxr.mozilla.org/mozilla-central/source/dom/canvas/CanvasRenderingContext2D.cpp#1037 Changed to just Clear() which seems to make more sense. > I don't think there are regions x and y - I'd just add clearHitRegions() > after all the removes - to test if clear works properly when there are no > regions, but also copy the whole try{} and do clear instead of the three > removes, to test the clear when there are valid regions around. Done.

A try run and this should be ready to go...

I have no try server access. Could someone push that for me? :)

Sure! https://treeherder.mozilla.org/#/jobs?repo=try&revision=5f665990af13

If I interpret the try run correctly, it looks all good. Setting checkin-needed.

this need Dom peer review for the change in WebIDL file dom/webidl/CanvasRenderingContext2D.webidl

Comment on attachment 8546729 [details] [diff] [review] bug1119527.patch r=me

https://developer.mozilla.org/en-US/Firefox/Releases/38#Interfaces.2FAPIs.2FDOM https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D.clearHitRegions