Bug 86891 – [Skia] Add a way to clear the cached GDI settings for cleartype

• Component: Platform
• Status: RESOLVED WONTFIX

[Shezan Baig]

The SPI_GETFONTSMOOTHINGTYPE system parameter is cached in SkiaFontWin.cpp in getDefaultGDITextFlags.  This means that if the setting is changed (through the Control Panel), skia-based text will continue using the first setting and the process needs to be restarted to pick up the new settings.

There should be some method to reset this cache.  In Windows, all top-level windows receive WM_SETTINGCHANGE that notifies the applications whenever a system-wide setting is changed.  If SkiaFontWin.cpp exposes a function to reset this cached value, an embedder can invoke this function whenever the WM_SETTINGCHANGE message is received.

MSDN Reference: http://msdn.microsoft.com/en-us/library/windows/desktop/ms725497%28v=vs.85%29.aspx

[Shezan Baig]

Created attachment 142782 [details]
Patch

[James Robinson]

Do you have a plan (or better patches) to follow through on the rest of the plumbing for this?

[Shezan Baig]

(In reply to comment #2)
> Do you have a plan (or better patches) to follow through on the rest of the plumbing for this?

Yeah, I could work on the plumbing to the chrome top-level window.  Will give me a chance to learn about how chrome's windows/tabs/processes work :)

[Shezan Baig]

After reading through the log of http://codereview.chromium.org/9370026, I'm not sure the plumbing for Chrome would be too beneficial, from the log (msg#20): "The WebKit code that uses Skia just queries it once and caches those values forever. But it's per renderer process, which come and go and so would eventually pick up the new settings"

[Darin Adler]

Comment on attachment 142782 [details]
Patch

Clearing flag from Skia-specific patch.