Initial implementation of WebUI generator (WUG) toolkit.

components/wug/view.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 CHROME_BROWSER_UI_WEBUI_WUG_VIEW_H_
+#define CHROME_BROWSER_UI_WEBUI_WUG_VIEW_H_
+
+#include "base/containers/scoped_ptr_hash_map.h"
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "components/wug/export.h"
+
+namespace base {
+class DictionaryValue;
+}
+
+namespace wug {
+
+class ViewModel;
+
+/**
+ * Base block of the UI. Every View instance is associated with single

[Nikita (slow), 2015/02/26 14:28:58]

nit: please mention what type of UI.
There's no mention about WebUI here.

[dzhioev (left Google), 2015/03/02 11:02:32]

Done.

+ * ViewModel instance which provides a context for the view. Views are
+ * hierarchical. Every child of view has an unique id.
+ */
+class WUG_EXPORT View {
+ public:
+  explicit View(const std::string& id);
+  virtual ~View();
+
+  virtual void Init();

[Denis Kuznetsov (DE-MUC), 2015/02/26 14:35:23]

It is not obvious that  OnReady should be called as a result of Init call,
should be documented on Init().
Generally, all virtual methods should have some contract that declares how
someone should override them.

[dzhioev (left Google), 2015/03/02 11:02:33]

Done.

+
+  // Root view is a view without parent.
+  // Root view should have id equal to "WUG_ROOT".
+  bool IsRootView() const;
+
+  ViewModel* GetViewModel() const;
+
+  // Called by view-model when it is ready.
+  void OnViewModelReady();
+
+  const std::string& id() const { return id_; }
+
+  // Every view has an unique path in a view hierarchy which is:
+  //  a) |id| for the root view;
+  //  b) concatenation of parent's path, $-sign and |id| for not-root views.
+  const std::string& path() const { return path_; }
+
+  View* GetChild(const std::string& id) const;

[Denis Kuznetsov (DE-MUC), 2015/02/26 14:35:23]

Add comment to method, including specifics on how missing children are handled.

[dzhioev (left Google), 2015/03/02 11:02:31]

Done.

+
+  // Called by view-model when it changes the context.
+  virtual void OnContextChanged(const base::DictionaryValue& diff) = 0;
+
+ protected:
+  // Called when view is ready, which means view-model and all children are
+  // ready.
+  virtual void OnReady();
+
+  // Forwards context changes stored in |diff| to view-model.
+  void UpdateContext(const base::DictionaryValue& diff);
+
+  // Forwards |event| to view-model.
+  void HandleEvent(const std::string& event);
+
+  bool ready() const { return ready_; }
+
+  base::ScopedPtrHashMap<std::string, View>& children() { return children_; }
+
+  void AddChild(View* child);
+
+  virtual std::string GetType() = 0;
+  virtual ViewModel* CreateViewModel() = 0;
+  virtual void CreateAndAddChildren() = 0;
+
+ private:
+  void OnChildReady(View* child);

[Denis Kuznetsov (DE-MUC), 2015/02/26 14:35:23]

Need a bit more details on "Ready" contract:
 - Can we  (dynamically) add children after Init is called? 
 - After whole tree is ready?

[dzhioev (left Google), 2015/03/02 11:02:31]

Added to comments here and near AddChild().

+  void OnChildrenReady();
+  void set_parent(View* parent) { parent_ = parent; }
+
+  View* parent_;
+  std::string id_;
+  std::string path_;
+
+  // Number of ready child views.

[Nikita (slow), 2015/02/26 14:28:58]

nit: number of child views that are ready.

[dzhioev (left Google), 2015/03/02 11:02:32]

Done.

+  int ready_children_;
+
+  bool view_model_ready_;
+  bool ready_;
+  base::ScopedPtrHashMap<std::string, View> children_;
+  scoped_ptr<ViewModel> view_model_;
+  base::WeakPtrFactory<View> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(View);
+};
+
+}  // namespace wug
+
+#endif  // CHROME_BROWSER_UI_WEBUI_WUG_VIEW_H_