WIP Hittest Component.

components/viz/hittest/hittest_aggregator.h

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_VIZ_HITTEST_HITTEST_AGGREGATOR_H_
+#define COMPONENTS_VIZ_HITTEST_HITTEST_AGGREGATOR_H_
+
+#include <stdint.h>
+
+#include <map>
+#include <memory>
+
+#include "cc/surfaces/surface_id.h"
+#include "cc/surfaces/surface_observer.h"
+#include "components/viz/hittest/hittest_export.h"
+#include "components/viz/hittest/public/interfaces/hittest_data.mojom.h"
+#include "ui/gfx/geometry/quad_f.h"
+
+namespace viz {
+
+namespace test {
+class HittestAggregatorTest;
+}
+
+// Hittest maintains maping between display regions and associated surfaces
+// in shared memory to enable efficient hit testing across processes.
+//
+// This is intended to be created in the viz or GPU process. For mus+ash this
+// will be true after the mus process split.
+
+#define LAST_REGION -2
+
+typedef std::map<cc::SurfaceId, hittest::mojom::HittestDataPtr> HittestDataMap;

[rjkroege, 2017/06/02 22:45:45]

chrome style prefers using

is a HittestDataPtr a std::unique_ptr<HittestData>?

+
+class HITTEST_EXPORT HittestAggregator : public cc::SurfaceObserver {

[rjkroege, 2017/06/02 22:45:45]

Note that since this is per display, you will need one of these for each
display. Not plumbed right for that afaik.

+  friend class test::HittestAggregatorTest;
+
+ public:
+  HittestAggregator();
+  ~HittestAggregator();
+
+  cc::SurfaceId SurfaceIdAtPoint(cc::SurfaceId root_surface_id,

[rjkroege, 2017/06/02 22:45:45]

we argued about this. Am not convinced that you need this.

+                                 const gfx::Point& point,
+                                 gfx::Point* transformed_point);
+  void SubmitHittestData(hittest::mojom::HittestDataPtr hittest_data);
+  void Aggregate(cc::SurfaceId display_surface_id);
+
+  // SurfaceObserver

[rjkroege, 2017/06/02 22:45:45]

overrides can be private

+  void OnSurfaceCreated(const cc::SurfaceInfo& surface_info) override {}
+  void OnSurfaceDestroyed(const cc::SurfaceId& surface_id) override {}
+  void OnSurfaceDamaged(const cc::SurfaceId& surface_id,
+                        const cc::BeginFrameAck& ack,
+                        bool* changed) override {}
+  void OnSurfaceDiscarded(const cc::SurfaceId& surface_id) override;
+  void OnSurfaceDamageExpected(const cc::SurfaceId& surface_id,
+                               const cc::BeginFrameArgs& args) override {}
+  void OnSurfaceWillDraw(const cc::SurfaceId& surface_id) override;
+
+ private:
+  std::map<cc::SurfaceId, hittest::mojom::HittestDataPtr> pending_;

[rjkroege, 2017/06/02 22:45:45]

use your using aka typedef?

+  std::map<cc::SurfaceId, hittest::mojom::HittestDataPtr> active_;

[rjkroege, 2017/06/02 22:45:45]

active_ are ones that have been marked as in the display CompositorFrame?

+
+  struct Element {
+    int child_count_;
+    hittest::mojom::HittestRegion region_;
+  };
+
+  Element* regions_[2];
+  Element* current_regions_;
+
+  void swap();
+};
+
+}  // namespace viz
+
+#endif  //  COMPONENTS_VIZ_HITTEST_HITTEST_AGGREGATOR_H_