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) {
+  gfx::Rect rect_1 = gfx::BoundingRect(b1.edge_top, b2.edge_bottom);
+  gfx::Rect rect_2 = gfx::BoundingRect(b1.edge_bottom, b2.edge_top);
+  return gfx::UnionRects(rect_1, rect_2);

[mohsen, 2014/11/10 22:25:59]

This might not work properly if width of one of rect_1 and rect_2 is zero.

[mfomitchev, 2014/11/10 23:07:29]

One of {rect_1, rect_2} will be equal to the union of rect_1 and rect_2, so I
think it's fine.

[mohsen, 2014/11/11 01:24:39]

At least, if both have width of zero (which for example happens when both
handles have the same x coordinate), gfx::UnionRect() will arbitrarily return
one which might not be the one you expect. (Also, I'm not sure if your first
sentence is correct in the general case).

[mfomitchev, 2014/11/12 18:32:49]

Yes, good point. Ok, I'll just go with the straightforward approach then. 

+}
+
 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