WIP Hittest Component.

components/viz/hittest/hittest.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_H_
+#define COMPONENTS_VIZ_HITTEST_HITTEST_H_
+
+#include <stdint.h>
+
+#include <map>
+#include <memory>
+
+#include "cc/output/compositor_frame.h"

[rjkroege, 2017/05/29 15:58:02]

not a correct dependency in my opinion.

+#include "cc/surfaces/surface_id.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 {
+
+// Hittest

[rjkroege, 2017/05/29 15:58:03]

you could merge this line with the one below

+// 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.
+

[rjkroege, 2017/05/29 15:58:03]

no space? git cl format?

+class HITTEST_EXPORT Hittest {
+ public:
+  static cc::SurfaceId SurfaceIdAtPoint(cc::SurfaceId root_surface_id,

[rjkroege, 2017/05/29 15:58:03]

i'm not sure that this is right.

[gklassen, 2017/06/05 21:32:13]

what would you change?

+                                        const gfx::Point& point,
+                                        gfx::Point* transformed_point) {
+    return GetInstance()->InternalGetSurfaceIdAtPoint(root_surface_id, point,
+                                                      transformed_point);
+  }
+
+  static void DisplayWillDrawAndSwap(bool will_draw_and_swap,

[rjkroege, 2017/05/29 15:58:03]

seems not right.

hittest component should provide some kind of DrawAndSwap observer
implementation that DrawandSwap will invoke? Can you modify DisplayCompositor to
have an observer of DrawAndSwap?

+                                     const cc::RenderPassList& render_passes) {
+    GetInstance()->Aggregate();
+  }
+
+ private:
+  static Hittest* instance_;
+
+  static Hittest* GetInstance() {

[rjkroege, 2017/05/29 15:58:03]

are you trying to create a singleton? I'd argue that you should avoid this.
Instead, the GpuService (or Framesinkmanager) should build the Hittest
component. That way you don't need to worry about singleton stuff

+    if (instance_ == NULL) {
+      instance_ = new Hittest();
+    }
+    return instance_;
+  }
+
+  Hittest();
+  ~Hittest();
+
+  std::map<cc::SurfaceId, viz::hittest::mojom::HittestData> pending_;
+
+  struct Region;
+  std::vector<Region> regions_[2];

[rjkroege, 2017/05/29 15:58:03]

this is the shared memory? AFAIK: vector is not a POD type?

+  std::vector<Region>* current_regions_;
+
+  cc::SurfaceId InternalGetSurfaceIdAtPoint(cc::SurfaceId root_surface_id,

[rjkroege, 2017/05/29 15:58:02]

these all need method comments?

+                                            const gfx::Point& point,
+                                            gfx::Point* transformed_point);
+
+  void SubmitHittestData(viz::hittest::mojom::HittestData& hittest_data);
+
+  void Aggregate();
+
+  void swap();
+};
+
+}  // namespace viz
+
+#endif  //  COMPONENTS_VIZ_HITTEST_HITTEST_H_