376245 - Drag image with custom image doesn't work any more

Status: RESOLVED FIXED

(Core :: DOM: Copy & Paste and Drag & Drop, defect)

Description

[Neil Deakin]

Attachment: testcase, needs chrome privileges

###!!! ASSERTION: DrawImage should no longer be called with thebes: 'Not Reached', file /builds/trunk-dragimage/mozilla/gfx/src/thebes/nsThebesRenderingContext.cpp, line 940

This was caused by bug 371434, which removed nsIRenderingContext::DrawImage What should be called instead, nsIImage::Draw or nsLayoutUtils::DrawImage?

Comment 1

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Probably nsLayoutUtils::DrawImage, at least if the caller is in layout.  Although, really, whichever one is easier.

Comment 2

[Neil Deakin]

Attachment: use nsIImage::Draw to draw the image instead

Comment 3

[Jeremy Lea]

(In reply to comment #2)
> Created an attachment (id=260471) [details]
> use nsIImage::Draw to draw the image instead
> 

I think this patch is wrong.  The second block converts dev pixels to app units (using ScaleRoundOut) then converts these (without scaling) to gfxFloats (which are dev pixels), then draws...  The conversion to app units should be skipped?  Unless the interface for img->Draw is screwed up and it's taking floating point app units...

Regards,
  -Jeremy

Comment 4

[Neil Deakin]

Attachment: yes, we can just get rid of the scaling part