There was logic in ViewGroup that assumed that an accelerated
view must always be able to get a display list for any child
that it was drawing. One situation occurred, however, that
caused a problem with this - a contacts activity was started
and not yet attached, but was being asked to render into an
accelerated canvas. We assumed that the child would have a display
list and simply called getDisplayList(). But since that call
returned null, we later deref'd the null object.
The fix is to check whether a child can have a display list
instead of assuming that it can just because the container view
is accelerated.
Change-Id: I7de62fd597ad50720c9585d621bec02e77c171df
* @hide
*/
protected void dispatchGetDisplayList() {}
+
+ /**
+ * A view that is not attached or hardware accelerated cannot create a display list.
+ * This method checks these conditions and returns the appropriate result.
+ *
+ * @return true if view has the ability to create a display list, false otherwise.
+ *
+ * @hide
+ */
+ public boolean canHaveDisplayList() {
+ if (mAttachInfo == null || mAttachInfo.mHardwareRenderer == null) {
+ return false;
+ }
+ return true;
+ }
/**
* <p>Returns a display list that can be used to draw this view again
* @hide
*/
public DisplayList getDisplayList() {
- if (mAttachInfo == null || mAttachInfo.mHardwareRenderer == null) {
+ if (!canHaveDisplayList()) {
return null;
}
} else if (layerType == LAYER_TYPE_NONE) {
// Delay getting the display list until animation-driven alpha values are
// set up and possibly passed on to the view
- hasDisplayList = true;
+ hasDisplayList = child.canHaveDisplayList();
}
}
}