On 22 nov, 12:00, Michael <[email protected]> wrote: > I have been using the GWT 2.1.0's MVP framework for a couple of weeks > now, and I really like it. > > However the flickering during place "transitions" really bothers me, > and today I tried to do something about it. > > Sofar I've found > this:http://code.google.com/p/google-web-toolkit/source/detail?r=9049 > > Notice the second part, "Also undoes demo-time hack that left stopped > widgets in place to reduce flicker" > > Using an activitymanager that leaves the stopped widgets in place > removed the flickering. But I assume there's a problem with this > approach?
See http://tbroyer.posterous.com/gwt-21-activities (which needs some update...) """In response to a user action (“show this mail conversation”, “go back to inbox”, etc.), the current activity has to be stopped and another started. As the next activity is starting (remember, this is already the current activity from the ActivityManager's point of view), the current activity (previous one actually) is still displayed, but it's already logically stopped (its onStop() method has already been called). Please note that this behavior will change in the next release: the display region's widget will be set to null as soon as the activity is stopped and until the next one is fully initialized. It's your job as a developer to choose which behavior you want: the view is disabled, or it might trigger navigation. Technically, it could still handle all user events but, because it's already stopped, it can be replaced at any given time and you won't have any notification (well, there's the widget's onUnload(), but anyway it's probably already too late to do anything useful). I'd therefore advise you to not do it, except to trigger navigation as it's about leaving the activity (which, you'll agree, doesn't conflicts with the already-stopped status of the activity). The rule of thumb is thus to disable any action when an activity is stopped (i.e. from its onStop() method), except possibly navigation. It's up to you to decide whether this is done by disabling (graying out) widgets or just turning a deaf ear to their events.""" > Anyone have a suggestion to a better strategy for removing the > flickering? Some sort of cache was mentionend in the above link. In the AcceptsOneWidget you give to the ActivityManager, just handle a 'null' widget differently, assuming your activities will never call setWidget(null) themselves (if they need to, you could have them pass a non-null IsWidget whose asWidget returns null). final SimplePanel realPanel = new SimplePanel(); activityManager;setWIdget(new AcceptsOneWidget() { public void setWidget(isWidget widget) { if (widget == null) { // note that widget.asWidget() == null goes the other path // here, you can do whatever you want to "reduce flicker"; if you don't call realPaneL;setWidget(null), then the view will lie around // you could also "mask" and/or "blur" it with a "glass panel" } else { realPanel.setWidget(widget); } } } -- You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-web-toolkit?hl=en.
