69453 - We need ability to disable and enable image loading "on-the-fly"

Status: VERIFIED FIXED

(Core Graveyard :: Embedding: APIs, defect, P4)

Description

[Marek Z. Jeziorek]

We need ability to disable and enable image loading "on-the-fly". The client 
will initially disable image loading and proceed to load and render the document 
body. When the document is complete, the client and interpose any required 
processing, then enable image loading, and request the images. This will give us 
the ability to modify the DOM immediately after the body is loaded, rather than 
waiting until after the images have loaded.

Comment 1

[Judson Valeski]

We need this on a per-top-level window basis. over to pavlov for suggestions. I
should be able to call some method on nsIWebBrowser() like setImages(boolean).

Comment 2

[Stuart Parmenter]

I will start work on this soon.

Comment 3

[Stuart Parmenter]

is this needed for embedding ?  if so, please add the keywords that are needed.

Comment 4

[Judson Valeski]

it's needed by embedding. there are no embedding keywords (just meta bugs (as 
indicated)). the "embed" keyword is depricated and shouldn't even be on here 
(removing).

Comment 5

[Stuart Parmenter]

could a style element not be dynamically added to the document as it is 
being loaded like:
img { display: none; }
which would keep the image frames from being created and thus block the image 
loads.  then remove the style rule and they would come in.

Comment 6

[Johnny Stenback (:jst)]

No, adding a stylesheet element would modify the content model which would screw
up roundtripping, and would add unexpected DOM nodes into the DOM tree. We need
an API to say images are turned off...

Comment 7

[Stuart Parmenter]

ok.. then should the embedding team provide some api for this for me to call to 
see if i can load an image or not?  should this use the nsIContentPolicy stuff?

Comment 8

[Judson Valeski]

cc'ing shaver about nsIContentPolicy.

nsIContentPolicy currently doesn't have per-top-leve-window policy querying 
capability, so we'd have to add that first.

nsIWebBrowserSetup is currently our per-top-level-window content enable/disable 
iface, maybe you could add an attrib there.

don't overlook that this is _per-window_, *not* global. Also, if you don't load 
an image on the first pass, can choose to load it later (as in, when the attrib 
got flipped)?

Comment 9

[Stuart Parmenter]

I don't really care how this is done, but someone is going to have to provide 
APIs for me to call with either a URL and/or a content node or frame and tell me 
if it can be loaded or not.  Let me know where there are available APIs to do 
the check and I'll add code to call your APIs.

Comment 10

[Stuart Parmenter]

shaver, for me to do this, nsIContentPolicy needs to known about windows.  Is 
there a bug filed on that?

Comment 11

[Michael Dunn]

Correction: Changing QA contact for the Embed API bugs to David Epstein.

Comment 12

[Stuart Parmenter]

shaver?

Comment 13

[Gagan]

so who is responsible for making nsIContentPolicy be window specific? shaver?

Comment 14

[Stuart Parmenter]

Reassigning to shaver.  The image code to check nsIContentPolicy is written and 
checked in (if 0'd out since I was unable to find a good way to test it.)  
Additional things are needed here such as making nsIContentPolicy be window-
aware.

Comment 15

[Mike Shaver (:shaver -- probably not reading bugmail closely)]

nsIContentPolicy doesn't need to know about per-window decisions, but whatever
implements it does. I'm not yet clear enough on exactly how these decisions will
be made (where does the data for the decision come from?) to do anything
meaningful with this.

I don't think nsIContentPolicy will need to change at all to accomodate this
stuff, but I'm happy to adjust the interface if I'm wrong.

Reassigning to gagan until I can get a clear description of how this feature
will work.

Comment 16

[Gagan]

Pavlov: can you better describe your requirements for shaver? 

Comment 17

[Stuart Parmenter]

I have no real requirements.  If you don't want an image, then don't request
it.  This is handled in nsImageFrame in layout with checks to things like the
security manager and nsIContentPolicy.  beyond that, I don't know much else.

Comment 18

[Stuart Parmenter]

as I understand it, this is an embedding requirement.  someone on embedding
should know better I would think?

Comment 19

[Gagan]

AFAIK there are 3 separate issues here-- 

1. Imagelib needs to check nsIContentPolicy to see if images are switched on or
off for this load. 

2. nsIContentPolicy needs to be able to determine if images need to be loaded or
not on a per window basis-- does so by being set by nsIWebBrowser[Setup](?)

3. nsIWebBrowser[Setup](?) needs a way to switch images off and on a global
level. 

Bug for 1 is this one that Pavlov will own and has very little left to do
(switch on an #if 0) I am going to file bug 2 which I think belongs with shaver
and bug 3 would be valeski? 

So assigning this back to pavlov (and going to create bugs for #2 and #3)

Comment 20

[Gagan]

adding dependencies...

Comment 21

[Stuart Parmenter]

valeski removed the ifdefs in nsImageFrame... is the work here basically done 
now, or is there more left to do?

Comment 22

[Judson Valeski]

I checked in the fixes for this yesterday. use nsIWebBrowserSetup to disable 
image loading in a particular window.

Comment 23

[David Epstein]

image loading on per win basis. per verfs of 81260 & 81263, verifying this.