mozart: Initial commit of the view manager.

services/ui/view_manager/view_state.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 SERVICES_UI_VIEW_MANAGER_VIEW_STATE_H_
+#define SERVICES_UI_VIEW_MANAGER_VIEW_STATE_H_
+
+#include <memory>
+#include <set>
+#include <unordered_map>
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "mojo/services/ui/views/interfaces/views.mojom.h"
+#include "services/ui/view_manager/view_layout_request.h"
+
+namespace view_manager {
+
+class ViewTreeState;
+
+// Describes the state of a particular view.
+// This object is owned by the ViewRegistry that created it.
+class ViewState {
+ public:
+  using ChildrenMap = std::unordered_map<uint32_t, ViewState*>;
+
+  ViewState(mojo::ui::ViewPtr view, uint32_t view_token_value);
+  ~ViewState();
+
+  base::WeakPtr<ViewState> GetWeakPtr() { return weak_factory_.GetWeakPtr(); }
+
+  // Gets the view interface, never null.
+  // Caller does not obtain ownership of the view.
+  mojo::ui::View* view() const { return view_.get(); }
+
+  // Gets the view token value used to refer to this view globally.
+  uint32_t view_token_value() const { return view_token_value_; }
+
+  // Sets the associated host implementation and takes ownership of it.
+  void set_view_host(mojo::ui::ViewHost* host) { view_host_.reset(host); }
+
+  // Sets the connection error handler for the view.
+  void set_view_connection_error_handler(const base::Closure& handler) {
+    view_.set_connection_error_handler(handler);
+  }
+
+  // Gets the view tree to which this view belongs, or null if none.
+  ViewTreeState* tree() const { return tree_; }
+
+  // Gets the parent view state, or null if none.
+  ViewState* parent() const { return parent_; }
+
+  // Gets the key that this child has in its container, or 0 if none.
+  uint32_t key() const { return key_; }
+
+  // Recursively sets the view tree to which this view and all of its
+  // descendents belongs.  Must not be null.  This method must only be called
+  // on root views.
+  void SetTree(ViewTreeState* tree, uint32_t key);
+
+  // Sets the parent view state pointer, the child's key in its parent,
+  // and set its view tree to that of its parent.  Must not be null.
+  void SetParent(ViewState* parent, uint32_t key);
+
+  // Resets the parent view state and tree pointers to null.
+  void ResetContainer();
+
+  // Gets the view's service provider.
+  void GetServiceProvider(
+      mojo::InterfaceRequest<mojo::ServiceProvider> service_provider);
+
+  // The map of children, indexed by child key.
+  // Child view state may be null if the child with the given key has
+  // become unavailable but not yet removed.
+  ChildrenMap& children() { return children_; }
+
+  // The set of children needing layout.
+  // This set must never contain non-existent or unavailable children.
+  std::set<uint32_t>& children_needing_layout() {
+    return children_needing_layout_;
+  }
+
+  // The list of pending layout requests.
+  std::vector<std::unique_ptr<ViewLayoutRequest>>& pending_layout_requests() {
+    return pending_layout_requests_;
+  }
+
+  // The layout parameters most recently processed by the view,
+  // or null if none.  These parameters are preserved across reparenting.
+  mojo::ui::ViewLayoutParamsPtr& layout_params() { return layout_params_; }
+
+  // The layout information most recently provided by the view in
+  // response to the value of |layout_params|, or null if none.  These
+  // results are preserved across reparenting.
+  mojo::ui::ViewLayoutInfoPtr& layout_info() { return layout_info_; }
+
+  // The id of the Surface which the view manager itself created to wrap the
+  // view's own Surface, or null if none.  The wrapped Surface is destroyed
+  // when the view is reparented so that the old parent can no longer embed
+  // the view's actual content.
+  mojo::SurfaceIdPtr& wrapped_surface() { return wrapped_surface_; }
+
+ private:
+  void SetTreeUnchecked(ViewTreeState* tree);
+
+  mojo::ui::ViewPtr view_;
+  const uint32_t view_token_value_;
+
+  std::unique_ptr<mojo::ui::ViewHost> view_host_;
+  ViewTreeState* tree_;
+  ViewState* parent_;
+  uint32_t key_;
+  ChildrenMap children_;
+  std::set<uint32_t> children_needing_layout_;
+  std::vector<std::unique_ptr<ViewLayoutRequest>> pending_layout_requests_;
+  mojo::ui::ViewLayoutParamsPtr layout_params_;
+  mojo::ui::ViewLayoutInfoPtr layout_info_;
+  mojo::SurfaceIdPtr wrapped_surface_;
+
+  base::WeakPtrFactory<ViewState> weak_factory_;  // must be last
+
+  DISALLOW_COPY_AND_ASSIGN(ViewState);
+};
+
+}  // namespace view_manager
+
+#endif  // SERVICES_UI_VIEW_MANAGER_VIEW_STATE_H_