Added views::ViewModelT<T>, a type-safe template version of ViewModel.

ui/views/view_model_utils.h

 // Copyright (c) 2012 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 UI_VIEWS_VIEW_MODEL_UTILS_H_
 #define UI_VIEWS_VIEW_MODEL_UTILS_H_
 
 #include "base/basictypes.h"
+#include "ui/views/view.h"
+#include "ui/views/view_model.h"
 #include "ui/views/views_export.h"
 
 namespace views {
 
-class View;
-class ViewModel;
-
 class VIEWS_EXPORT ViewModelUtils {
  public:
   enum Alignment {
     HORIZONTAL,
     VERTICAL
   };
 
   // Sets the bounds of each view to its ideal bounds.
-  static void SetViewBoundsToIdealBounds(const ViewModel& model);
+  template <class T>
+  static void SetViewBoundsToIdealBounds(const ViewModel<T>& model);
 
   // Returns true if the Views in |model| are at their ideal bounds.
-  static bool IsAtIdealBounds(const ViewModel& model);
+  template <class T>
+  static bool IsAtIdealBounds(const ViewModel<T>& model);
 
   // Returns the index to move |view| to based on a coordinate of |x| and |y|.
-  static int DetermineMoveIndex(const ViewModel& model,
+  template <class T>
+  static int DetermineMoveIndex(const ViewModel<T>& model,
                                 View* view,
                                 Alignment alignment,
                                 int x,
                                 int y);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(ViewModelUtils);
 };
 
+namespace {
+
+// Used in calculating ideal bounds.
+int primary_axis_coordinate(ViewModelUtils::Alignment alignment,
+                            int x,
+                            int y) {
+  return alignment == ViewModelUtils::HORIZONTAL ? x : y;
+}
+
+}  // namespace
+
+// static
+template <class T>
+void ViewModelUtils::SetViewBoundsToIdealBounds(const ViewModel<T>& model) {
+  for (int i = 0; i < model.view_size(); ++i)
+    model.view_at(i)->SetBoundsRect(model.ideal_bounds(i));
+}
+
+// static
+template <class T>
+bool ViewModelUtils::IsAtIdealBounds(const ViewModel<T>& model) {
+  for (int i = 0; i < model.view_size(); ++i) {
+    View* view = model.view_at(i);
+    if (view->bounds() != model.ideal_bounds(i))
+      return false;
+  }
+  return true;
+}
+
+// static
+template <class T>
+int ViewModelUtils::DetermineMoveIndex(const ViewModel<T>& model,
+                                       View* view,
+                                       Alignment alignment,
+                                       int x,
+                                       int y) {
+  int value = primary_axis_coordinate(alignment, x, y);
+  int current_index = model.GetIndexOfView(view);
+  DCHECK_NE(-1, current_index);
+  for (int i = 0; i < current_index; ++i) {
+    int mid_point = primary_axis_coordinate(
+        alignment,
+        model.ideal_bounds(i).x() + model.ideal_bounds(i).width() / 2,
+        model.ideal_bounds(i).y() + model.ideal_bounds(i).height() / 2);
+    if (value < mid_point)
+      return i;
+  }
+
+  if (current_index + 1 == model.view_size())
+    return current_index;
+
+  // For indices after the current index ignore the bounds of the view being
+  // dragged. This keeps the view from bouncing around as moved.
+  int delta = primary_axis_coordinate(
+      alignment,
+      model.ideal_bounds(current_index + 1).x() -
+      model.ideal_bounds(current_index).x(),
+      model.ideal_bounds(current_index + 1).y() -
+      model.ideal_bounds(current_index).y());
+  for (int i = current_index + 1; i < model.view_size(); ++i) {
+    const gfx::Rect& bounds(model.ideal_bounds(i));
+    int mid_point = primary_axis_coordinate(
+        alignment,
+        bounds.x() + bounds.width() / 2 - delta,
+        bounds.y() + bounds.height() / 2 - delta);
+    if (value < mid_point)
+      return i - 1;
+  }
+  return model.view_size() - 1;
+}
+
 }  // namespace views
 
 #endif  // UI_VIEWS_VIEW_MODEL_UTILS_H_