375519 - window.innerWidth/Height units

Status: RESOLVED FIXED

(Core :: DOM: Core & HTML, defect)

Description

[Marco Pesenti Gritti]

window.innerWidth/Height are currently returned in device pixels rather than in CSS pixels.

On high DPI screens this breaks sites like google maps or gtalk which use window.innerWidth/Height to adapt divs position/size to the browser window.

Is there a reason for this behavior or is it just a bug?

(screen.width and screen.height are returned in CSS pixels)

Comment 1

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Just a bug I presume.

Comment 2

[Eli Friedman]

Just a bug; high DPI hasn't been getting much testing.

Probably just need to add a bit of code to nsGlobalWindow::Get/SetInnerWidth/Height to grab a prescontext and do something like presContext::AppUnitsToIntCSSPixels(presContext->DevPixelsToAppUnits(width)); it's a bit messy, but pretty straightforward.  The prescontext can be obtained from nsIDocShell.

I'll put together a patch soon.

Comment 3

[Marco Pesenti Gritti]

Attachment: Convert between device and css pixels for window.InnerWidth/Height

Something like this?

Comment 4

[Eli Friedman]

(In reply to comment #3)
> Created an attachment (id=259996) [details]
> Convert between device and css pixels for window.InnerWidth/Height
> 
> Something like this?

Looks good.  Just to be on the safe side, though, I'd null-check mDocShell. I'm not quite sure when it can be null.

Comment 5

[Marco Pesenti Gritti]

Attachment: Checks for mDocShell

I used NS_ENSURE_STATE(mDocShell)... From what I can tell looking at nsDocShell.cpp this is an unexpected state. Also we are doing the same in GlobalWindow::Prompt. Make sense?

Comment 6

[Eli Friedman]

Comment on attachment 260139 [details] [diff] [review]
Checks for mDocShell

NS_ENSURE_STATE is fine.

Comment 7

[Marco Pesenti Gritti]

[marco@localhost mozilla]$ cvs commit dom/src/base/nsGlobalWindow.cpp
Checking in dom/src/base/nsGlobalWindow.cpp;
/cvsroot/mozilla/dom/src/base/nsGlobalWindow.cpp,v  <--  nsGlobalWindow.cpp
new revision: 1.919; previous revision: 1.918
done

Comment 8

[Johnny Stenback (:jst)]

For the record, this caused bug 400204.