Bug 34501 – [Qt] Poor Performance of QtWebKit layouting on Mac

• Status: RESOLVED
• Resolution: DUPLICATE
• Component: Platform

[Justin Camerer]

Created attachment 47971 [details]
tarball of some profiling output of webkit vs qtwebkit

In comparison to Safari or Chrome, QtWebKit is incredibly slow in a few areas. The main problems are:

  * Scroll speed (causes dom manipulation in this example)
  * Window resizing
  * CSS resizable columns of from “resize: horizontal”

I am attempting to create a cross platform application that depends on these working smoothly. Have these problems surfaced before?

[Benjamin Poulain]

  * Scroll speed (causes dom manipulation in this example)

This is a known issue. On Mac, with Qt, the scroll() function does not blit the pixels, it forces a full repaint of the view.

This is not a WebKit issue, and the developers of Qt are aware of the problem.
You can try to render the web page with OpenGL. OpenGL always do full update, but the speed of rendering should compensate.


  * Window resizing
  * CSS resizable columns of from “resize: horizontal”

These are layouting problems. I did not know there was an issue on Mac, some profiling will be needed.

[Benjamin Poulain]

*** This bug has been marked as a duplicate of bug 38179 ***