void
InputQueue::SweepDepletedBlocks()
{
// We're going to start a new block, so clear out any depleted blocks at the head of the queue.
// See corresponding comment in ProcessInputBlocks.
while (!mInputBlockQueue.IsEmpty()) {
CancelableBlockState* block = mInputBlockQueue[0].get();
if (!block->IsReadyForHandling() || block->HasEvents()) {
break;
}
INPQ_LOG("discarding depleted %s block %p\n", block->Type(), block);
mInputBlockQueue.RemoveElementAt(0);
}
}
void
InputQueue::ProcessInputBlocks() {
APZThreadUtils::AssertOnControllerThread();
do {
CancelableBlockState* curBlock = CurrentBlock();
if (!curBlock->IsReadyForHandling()) {
break;
}
INPQ_LOG("processing input block %p; preventDefault %d target %p\n",
curBlock, curBlock->IsDefaultPrevented(),
curBlock->GetTargetApzc().get());
RefPtr<AsyncPanZoomController> target = curBlock->GetTargetApzc();
// target may be null here if the initial target was unconfirmed and then
// we later got a confirmed null target. in that case drop the events.
if (!target) {
curBlock->DropEvents();
} else if (curBlock->IsDefaultPrevented()) {
curBlock->DropEvents();
target->ResetInputState();
} else {
UpdateActiveApzc(curBlock->GetTargetApzc());
curBlock->HandleEvents();
}
MOZ_ASSERT(!curBlock->HasEvents());
if (mInputBlockQueue.Length() == 1 && curBlock->MustStayActive()) {
// Some types of blocks (e.g. touch blocks) accumulate events until the
// next input block is started. Therefore we cannot remove the block from
// the queue until we have started another block. This block will be
// removed by SweepDeletedBlocks() whenever a new block is added.
break;
}
// If we get here, we know there are more touch blocks in the queue after
// |curBlock|, so we can remove |curBlock| and try to process the next one.
INPQ_LOG("discarding processed %s block %p\n", curBlock->Type(), curBlock);
mInputBlockQueue.RemoveElementAt(0);
} while (!mInputBlockQueue.IsEmpty());
}
