Support for Adaptive Handle Orientation

ui/touch_selection/touch_selection_controller.cc

 // Copyright 2014 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/touch_selection/touch_selection_controller.h"
 
 #include "base/auto_reset.h"
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 
 namespace ui {
 namespace {
 
-gfx::Vector2dF ComputeLineOffsetFromBottom(const SelectionBound& bound) {
-  gfx::Vector2dF line_offset =
-      gfx::ScaleVector2d(bound.edge_top() - bound.edge_bottom(), 0.5f);
+gfx::Vector2dF ComputeLineOffsetFromBottom(const SelectionBound& bound,
+                                           bool compute_from_top) {
+  gfx::Vector2dF vertical_offset =
+      compute_from_top ? (bound.edge_bottom() - bound.edge_top())
+                       : (bound.edge_top() - bound.edge_bottom());
+  gfx::Vector2dF line_offset = gfx::ScaleVector2d(vertical_offset, 0.5f);
   // An offset of 5 DIPs is sufficient for most line sizes. For small lines,
   // using half the line height avoids synthesizing a point on a line above
   // (or below) the intended line.
   const gfx::Vector2dF kMaxLineOffset(5.f, 5.f);
   line_offset.SetToMin(kMaxLineOffset);
   line_offset.SetToMax(-kMaxLineOffset);
   return line_offset;
 }
 
 TouchHandleOrientation ToTouchHandleOrientation(SelectionBound::Type type) {
@@ skipping 25 matching lines @@
       response_pending_input_event_(INPUT_EVENT_TYPE_NONE),
       start_orientation_(TouchHandleOrientation::UNDEFINED),
       end_orientation_(TouchHandleOrientation::UNDEFINED),
       is_insertion_active_(false),
       activate_insertion_automatically_(false),
       is_selection_active_(false),
       activate_selection_automatically_(false),
       selection_empty_(false),
       selection_editable_(false),
       temporarily_hidden_(false),
+      viewport_size_changed_(false),
       selection_handle_dragged_(false) {
   DCHECK(client_);
 }
 
 TouchSelectionController::~TouchSelectionController() {
 }
 
+void TouchSelectionController::OnViewportChanged(
+    const gfx::RectF viewport_rect) {
+  if (viewport_rect_ == viewport_rect)
+    return;
+  viewport_size_changed_ = true;
+  viewport_rect_ = viewport_rect;
+}
+
 void TouchSelectionController::OnSelectionBoundsChanged(
     const SelectionBound& start,
     const SelectionBound& end) {
-  if (start == start_ && end_ == end)
+  if (start == start_ && end_ == end && !viewport_size_changed_)
     return;
 
   start_ = start;
   end_ = end;
   start_orientation_ = ToTouchHandleOrientation(start_.type());
   end_orientation_ = ToTouchHandleOrientation(end_.type());
+  viewport_size_changed_ = false;
 
   if (!activate_selection_automatically_ &&
       !activate_insertion_automatically_) {
     DCHECK_EQ(INPUT_EVENT_TYPE_NONE, response_pending_input_event_);
     return;
   }
 
   // Ensure that |response_pending_input_event_| is cleared after the method
   // completes, while also making its current value available for the duration
   // of the call.
@@ skipping 285 matching lines @@
   client_->OnSelectionEvent(INSERTION_CLEARED, gfx::PointF());
 }
 
 void TouchSelectionController::ActivateSelection() {
   DCHECK(!is_insertion_active_);
 
   if (!start_selection_handle_) {
     start_selection_handle_.reset(new TouchHandle(this, start_orientation_));
   } else {
     start_selection_handle_->SetEnabled(true);
-    start_selection_handle_->SetOrientation(start_orientation_);
+    start_selection_handle_->SetOrientation(start_orientation_, viewport_rect_,
+                                            start_.edge_bottom());
   }
 
   if (!end_selection_handle_) {
     end_selection_handle_.reset(new TouchHandle(this, end_orientation_));
   } else {
     end_selection_handle_->SetEnabled(true);
-    end_selection_handle_->SetOrientation(end_orientation_);
+    end_selection_handle_->SetOrientation(end_orientation_, viewport_rect_,
+                                          end_.edge_bottom());
   }
 
   // As a long press received while a selection is already active may trigger
   // an entirely new selection, notify the client but avoid sending an
   // intervening SELECTION_CLEARED update to avoid unnecessary state changes.
   if (!is_selection_active_ || response_pending_input_event_ == LONG_PRESS) {
     if (is_selection_active_) {
       // The active selection session finishes with the start of the new one.
       LogSelectionEnd();
     }
@@ skipping 20 matching lines @@
 void TouchSelectionController::ResetCachedValuesIfInactive() {
   if (is_selection_active_ || is_insertion_active_)
     return;
   start_ = SelectionBound();
   end_ = SelectionBound();
   start_orientation_ = TouchHandleOrientation::UNDEFINED;
   end_orientation_ = TouchHandleOrientation::UNDEFINED;
 }
 
 const gfx::PointF& TouchSelectionController::GetStartPosition() const {
+  if (start_selection_handle_ && start_selection_handle_->is_inverted())
+    return start_.edge_top();
   return start_.edge_bottom();
 }
 
 const gfx::PointF& TouchSelectionController::GetEndPosition() const {
+  if (end_selection_handle_ && end_selection_handle_->is_inverted())
+    return end_.edge_top();
   return end_.edge_bottom();
 }
 
 gfx::Vector2dF TouchSelectionController::GetStartLineOffset() const {
-  return ComputeLineOffsetFromBottom(start_);
+  DCHECK(start_selection_handle_);
+  bool compute_from_top = start_selection_handle_->is_inverted();
+  return ComputeLineOffsetFromBottom(start_, compute_from_top);
 }
 
 gfx::Vector2dF TouchSelectionController::GetEndLineOffset() const {
-  return ComputeLineOffsetFromBottom(end_);
+  DCHECK(end_selection_handle_);
+  bool compute_from_top = end_selection_handle_->is_inverted();
+  return ComputeLineOffsetFromBottom(end_, compute_from_top);
 }
 
 bool TouchSelectionController::GetStartVisible() const {
   return start_.visible() && !temporarily_hidden_;
 }
 
 bool TouchSelectionController::GetEndVisible() const {
   return end_.visible() && !temporarily_hidden_;
 }
 
@@ skipping 13 matching lines @@
     base::TimeDelta duration = base::TimeTicks::Now() - selection_start_time_;
     UMA_HISTOGRAM_CUSTOM_TIMES("Event.TouchSelection.WasDraggedDuration",
                                duration,
                                base::TimeDelta::FromMilliseconds(500),
                                base::TimeDelta::FromSeconds(60),
                                60);
   }
 }
 
 }  // namespace ui