Implementing directional text selection handles

ui/base/touch/touch_editing_controller.cc

 // Copyright (c) 2013 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.
 
 #include "ui/base/touch/touch_editing_controller.h"
 
 namespace ui {
 
 namespace {
 TouchSelectionControllerFactory* g_shared_instance = NULL;
 }  // namespace
 
+SelectionBound::SelectionBound()
+    : type(ui::SelectionBound::EMPTY) {
+}
+
+SelectionBound::~SelectionBound() {
+}
+
+int SelectionBound::GetHeight() const {
+  return edge_bottom.y() - edge_top.y();
+}
+
+bool operator==(const SelectionBound& lhs, const SelectionBound& rhs) {
+  return lhs.type == rhs.type && lhs.edge_top == rhs.edge_top &&
+         lhs.edge_bottom == rhs.edge_bottom;
+}
+
+bool operator!=(const SelectionBound& lhs, const SelectionBound& rhs) {
+  return !(lhs == rhs);
+}
+
+gfx::Rect RectBetweenSelectionBounds(const SelectionBound& b1,
+                                     const SelectionBound& b2) {
+  int all_x[] ={
+      b1.edge_top.x(), b2.edge_top.x(), b1.edge_bottom.x(), b2.edge_bottom.x()
+  };
+  int all_y[] = {
+      b1.edge_top.y(), b2.edge_top.y(), b1.edge_bottom.y(), b2.edge_bottom.y()
+  };
+  const int num_elements = arraysize(all_x);
+  COMPILE_ASSERT(arraysize(all_y) == num_elements, array_size_mismatch);
+
+  int left = *std::min_element(all_x, all_x + num_elements);
+  int top = *std::min_element(all_y, all_y + num_elements);
+  int right = *std::max_element(all_x, all_x + num_elements);
+  int bottom = *std::max_element(all_y, all_y + num_elements);
+
+  return gfx::Rect(left, top, right - left, bottom - top);
+}
+
 TouchSelectionController* TouchSelectionController::create(
     TouchEditable* client_view) {
   if (g_shared_instance)
     return g_shared_instance->create(client_view);
   return NULL;
 }
 
 // static
 void TouchSelectionControllerFactory::SetInstance(
     TouchSelectionControllerFactory* instance) {
   g_shared_instance = instance;
 }
 
 }  // namespace ui