PinchViewports::PinchViewports(WebViewImpl* owner)
: m_owner(owner)
, m_innerViewportContainerLayer(GraphicsLayer::create(m_owner->graphicsLayerFactory(), this))
, m_pageScaleLayer(GraphicsLayer::create(m_owner->graphicsLayerFactory(), this))
, m_innerViewportScrollLayer(GraphicsLayer::create(m_owner->graphicsLayerFactory(), this))
, m_overlayScrollbarHorizontal(GraphicsLayer::create(m_owner->graphicsLayerFactory(), this))
, m_overlayScrollbarVertical(GraphicsLayer::create(m_owner->graphicsLayerFactory(), this))
{
ASSERT(m_owner);
WebCore::ScrollingCoordinator* coordinator = m_owner->page()->scrollingCoordinator();
ASSERT(coordinator);
coordinator->setLayerIsContainerForFixedPositionLayers(m_innerViewportScrollLayer.get(), true);
// No need for the inner viewport to clip, since the compositing
// surface takes care of it -- and clipping here would interfere with
// dynamically-sized viewports on Android.
m_innerViewportContainerLayer->setMasksToBounds(false);
m_innerViewportScrollLayer->platformLayer()->setScrollClipLayer(
m_innerViewportContainerLayer->platformLayer());
m_innerViewportScrollLayer->platformLayer()->setUserScrollable(true, true);
m_innerViewportContainerLayer->addChild(m_pageScaleLayer.get());
m_pageScaleLayer->addChild(m_innerViewportScrollLayer.get());
m_innerViewportContainerLayer->addChild(m_overlayScrollbarHorizontal.get());
m_innerViewportContainerLayer->addChild(m_overlayScrollbarVertical.get());
// Setup the inner viewport overlay scrollbars.
setupScrollbar(WebScrollbar::Horizontal);
setupScrollbar(WebScrollbar::Vertical);
}
// Modifies the top of the graphics layer tree to add layers needed to support
// the inner/outer viewport fixed-position model for pinch zoom. When finished,
// the tree will look like this (with * denoting added layers):
//
// *rootTransformLayer
// +- *innerViewportContainerLayer (fixed pos container)
// +- *pageScaleLayer
// | +- *innerViewportScrollLayer
// | +-- overflowControlsHostLayer (root layer)
// | +-- outerViewportContainerLayer (fixed pos container) [frame container layer in RenderLayerCompositor]
// | | +-- outerViewportScrollLayer [frame scroll layer in RenderLayerCompositor]
// | | +-- content layers ...
// | +-- horizontal ScrollbarLayer (non-overlay)
// | +-- verticalScrollbarLayer (non-overlay)
// | +-- scroll corner (non-overlay)
// +- *horizontalScrollbarLayer (overlay)
// +- *verticalScrollbarLayer (overlay)
//
void PinchViewport::attachToLayerTree(GraphicsLayer* currentLayerTreeRoot, GraphicsLayerFactory* graphicsLayerFactory)
{
TRACE_EVENT1("blink", "PinchViewport::attachToLayerTree", "currentLayerTreeRoot", (bool)currentLayerTreeRoot);
if (!currentLayerTreeRoot) {
m_innerViewportScrollLayer->removeAllChildren();
return;
}
if (currentLayerTreeRoot->parent() && currentLayerTreeRoot->parent() == m_innerViewportScrollLayer)
return;
if (!m_innerViewportScrollLayer) {
ASSERT(!m_overlayScrollbarHorizontal
&& !m_overlayScrollbarVertical
&& !m_pageScaleLayer
&& !m_innerViewportContainerLayer);
// FIXME: The root transform layer should only be created on demand.
m_rootTransformLayer = GraphicsLayer::create(graphicsLayerFactory, this);
m_innerViewportContainerLayer = GraphicsLayer::create(graphicsLayerFactory, this);
m_pageScaleLayer = GraphicsLayer::create(graphicsLayerFactory, this);
m_innerViewportScrollLayer = GraphicsLayer::create(graphicsLayerFactory, this);
m_overlayScrollbarHorizontal = GraphicsLayer::create(graphicsLayerFactory, this);
m_overlayScrollbarVertical = GraphicsLayer::create(graphicsLayerFactory, this);
WebCore::ScrollingCoordinator* coordinator = m_frameHost.page().scrollingCoordinator();
ASSERT(coordinator);
coordinator->setLayerIsContainerForFixedPositionLayers(m_innerViewportScrollLayer.get(), true);
// Set masks to bounds so the compositor doesn't clobber a manually
// set inner viewport container layer size.
m_innerViewportContainerLayer->setMasksToBounds(m_frameHost.settings().mainFrameClipsContent());
m_innerViewportContainerLayer->setSize(m_size);
m_innerViewportScrollLayer->platformLayer()->setScrollClipLayer(
m_innerViewportContainerLayer->platformLayer());
m_innerViewportScrollLayer->platformLayer()->setUserScrollable(true, true);
m_rootTransformLayer->addChild(m_innerViewportContainerLayer.get());
m_innerViewportContainerLayer->addChild(m_pageScaleLayer.get());
m_pageScaleLayer->addChild(m_innerViewportScrollLayer.get());
m_innerViewportContainerLayer->addChild(m_overlayScrollbarHorizontal.get());
m_innerViewportContainerLayer->addChild(m_overlayScrollbarVertical.get());
// Ensure this class is set as the scroll layer's ScrollableArea.
coordinator->scrollableAreaScrollLayerDidChange(this);
// Setup the inner viewport overlay scrollbars.
setupScrollbar(WebScrollbar::Horizontal);
setupScrollbar(WebScrollbar::Vertical);
}
m_innerViewportScrollLayer->removeAllChildren();
m_innerViewportScrollLayer->addChild(currentLayerTreeRoot);
// We only need to disable the existing (outer viewport) scrollbars
// if the existing ones are already overlay.
// FIXME: If we knew in advance before the overflowControlsHostLayer goes
// away, we would re-enable the drawing of these scrollbars.
// FIXME: This doesn't seem to work (at least on Android). Commenting out for now until
// I figure out how to access RenderLayerCompositor from here.
// if (GraphicsLayer* scrollbar = m_frameHost->compositor()->layerForHorizontalScrollbar())
// scrollbar->setDrawsContent(!page->mainFrame()->view()->hasOverlayScrollbars());
// if (GraphicsLayer* scrollbar = m_frameHost->compositor()->layerForVerticalScrollbar())
// scrollbar->setDrawsContent(!page->mainFrame()->view()->hasOverlayScrollbars());
}