Bug 165300 – [GTK] Process accelerated compositing env variables only if they are really enabled

• Component: WebKitGTK
• Status: RESOLVED FIXED

[Tomas Popela]

Only process WEBKIT_FORCE_COMPOSITING_MODE and WEBKIT_DISABLE_COMPOSITING_MODE env variables if they are really enabled (eg. WEBKIT_DISABLE_COMPOSITING_MODE=1) and ignore others (eg. WEBKIT_DISABLE_COMPOSITING_MODE=0). This will help WebKitGTK+ consumers to be able to not disable AC through the env variable if the user wants the AC to be turned on (he will usually have "export WEBKIT_DISABLE_COMPOSITING_MODE=0" somewhere).

[Tomas Popela]

Created attachment 295940 [details]
Patch

[Michael Catanzaro]

Comment on attachment 295940 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=295940&action=review

> Source/WebKit2/UIProcess/gtk/WebPreferencesGtk.cpp:50
> -    if (getenv("WEBKIT_FORCE_COMPOSITING_MODE"))
> +    if (!g_strcmp0(getenv("WEBKIT_FORCE_COMPOSITING_MODE"), "1"))

How about if (g_strcmp0(getenv("WEBKIT_FORCE_COMPOSITING_MODE"), "0")), that way you can disable it by setting it to 0, but set it to anything else and it'd still be enabled? That seems more familiar to me; what do other popular applications do?

> Source/WebKit2/UIProcess/gtk/WebPreferencesGtk.cpp:54
> -    if (getenv("WEBKIT_DISABLE_COMPOSITING_MODE")) {
> +    if (!g_strcmp0(getenv("WEBKIT_DISABLE_COMPOSITING_MODE"), "1")) {

Ditto.

[Tomas Popela]

(In reply to comment #2)
> Comment on attachment 295940 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=295940&action=review
> 
> > Source/WebKit2/UIProcess/gtk/WebPreferencesGtk.cpp:50
> > -    if (getenv("WEBKIT_FORCE_COMPOSITING_MODE"))
> > +    if (!g_strcmp0(getenv("WEBKIT_FORCE_COMPOSITING_MODE"), "1"))
> 
> How about if (g_strcmp0(getenv("WEBKIT_FORCE_COMPOSITING_MODE"), "0")), that
> way you can disable it by setting it to 0, but set it to anything else and
> it'd still be enabled? That seems more familiar to me; what do other popular
> applications do?

Could be as I don't have a strong preference on any of them. I don't any env variable apart from gtk's GTK_OVERLAY_SCROLLING:

gtk/gtkscrolledwindow.c:4415:  if (g_strcmp0 (g_getenv ("GTK_OVERLAY_SCROLLING"), "0") == 0)
 
and that behaves the same way you described.. Let's rework the patch :)..

[Tomas Popela]

Created attachment 296135 [details]
Patch

[Michael Catanzaro]

Comment on attachment 296135 [details]
Patch

This way also avoids breaking previous instructions. I doubt anybody was dumb enough to define WEBKIT_FORCE_COMPOSITING_MODE=0 and expect to get compositing mode, but it's not hard to imagine someone using WEBKIT_FORCE_COMPOSITING_MODE= or something.

[Tomas Popela]

Comment on attachment 296135 [details]
Patch

Clearing flags on attachment: 296135

Committed r209391: <http://trac.webkit.org/changeset/209391>

[Tomas Popela]

All reviewed patches have been landed.  Closing bug.

[WebKit Commit Bot]

Re-opened since this is blocked by bug 165501

[Michael Catanzaro]

Sorry about the bad advice, Tom. :)  To do it properly you'll need to check if the env variable is set, and then use plain strcmp instead of g_strcmp0 only if it's set, like Milan suggested.

[Tomas Popela]

Created attachment 296508 [details]
Patch

[Tomas Popela]

Comment on attachment 296508 [details]
Patch

Clearing flags on attachment: 296508

Committed r209534: <http://trac.webkit.org/changeset/209534>

[Tomas Popela]

All reviewed patches have been landed.  Closing bug.