[webkit-dev] Anonymous Rendering Objects in Web Inspector

Alex Milowski alex at milowski.org
Thu Jan 21 11:22:14 PST 2010

On Thu, Jan 21, 2010 at 10:43 AM, Dan Bernstein <mitz at apple.com> wrote:
> On Jan 21, 2010, at 9:44 AM, Alex Milowski wrote:
>> In my MathML code I often wrap the direct rendering objects for a particular
>> element in an anonymous rendering object.  When I inspect these elements
>> I get the particular rendering object for the element but between that
>> element and the parent's rendering object there are these anonymous
>> objects used for layout control.
>> Is there some way to see these objects when you inspect the element?
>> Is there another tool I can use to inspect the render object tree?
> The Mac OS X version of Safari includes a Show Render Tree command in its internal Debug menu. To enable the Debug menu, use
> defaults write com.apple.Safari IncludeInternalDebugMenu -bool YES

So, when I try this with the trunk I get an error on the console:

   2010-01-21 11:17:24.288 Safari[20905:80f] *** -[WebRenderNode
initWithWebFrameView:]: unrecognized selector sent to instance

and nothing happens.

> It would be great to add more knowledge of the render tree, including anonymous renderers, to the Web Inspector!

It would be never nice to be able to select an element in the web
inspector and then be
able to say "show me the rendering tree".  That would result in the
tree display with that
element's rendering object being selected.

I would want to be able have similar information to what is displayed
in the web inspector
for an element.  Specifically, I'd want the computed style and metrics.

--Alex Milowski
"The excellence of grammar as a guide is proportional to the paucity of the
inflexions, i.e. to the degree of analysis effected by the language

Bertrand Russell in a footnote of Principles of Mathematics

More information about the webkit-dev mailing list