On Mon, Aug 16, 2010 at 9:43 PM, Dean Jackson <d...@apple.com> wrote:
> It was suggested I bring this to webkit-dev. > > There was some recent work to move the many parameters passed to the Page > constructor into a single PageClients structure. The current assumption is > that if a feature is enabled (at runtime or compile time) then Page will > always get a non-null client for that feature. > > This allows the Page constructor to have something like this: > > , m_deviceMotionController(RuntimeEnabledFeatures::deviceMotionEnabled() ? > n > ew DeviceMotionController(pageClients.deviceMotionClient) : 0) > > and DeviceMotionController's constructor has an ASSERT(m_client). > > The problem is that not every Page needs every client. SVGImage, for > example, creates a Page without all clients. Some platform ports branch > around this code. The current solution is to create EmptyClient > implementations. > > https://bugs.webkit.org/show_bug.cgi?id=43848 > https://bugs.webkit.org/show_bug.cgi?id=43533 > > Related discussion: > https://lists.webkit.org/pipermail/webkit-dev/2010-July/013597.html > > Wouldn't it be easier to allow null clients than to have these EmptyClient > implementations? > > Dean > > I think that'd be a lot of null checks. It seems like it could add a fair bit of code throughout WebCore, and folks would have to be careful not to forget any null checks. EmptyClients seems like a fairly isolated solution, which only requires maintenance when a client interface changes. -Darin
_______________________________________________ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
