Home | History | Annotate | Download | only in input 
      1 // Copyright 2014 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #include "content/browser/renderer_host/input/gesture_text_selector.h"
      6 
      7 #include "ui/events/event_constants.h"
      8 #include "ui/events/gesture_detection/gesture_event_data.h"
      9 #include "ui/events/gesture_detection/motion_event.h"
     10 
     11 namespace content {
     12 
     13 GestureTextSelector::GestureTextSelector(GestureTextSelectorClient* client)
     14     : client_(client),
     15       text_selection_triggered_(false),
     16       anchor_x_(0.0f),
     17       anchor_y_(0.0f) {
     18 }
     19 
     20 GestureTextSelector::~GestureTextSelector() {
     21 }
     22 
     23 bool GestureTextSelector::OnTouchEvent(const ui::MotionEvent& event) {
     24   if (event.GetAction() == ui::MotionEvent::ACTION_DOWN) {
     25     // Only trigger selection on ACTION_DOWN to prevent partial touch or gesture
     26     // sequences from being forwarded.
     27     text_selection_triggered_ = ShouldStartTextSelection(event);
     28   }
     29   return text_selection_triggered_;
     30 }
     31 
     32 bool GestureTextSelector::OnGestureEvent(const ui::GestureEventData& gesture) {
     33   if (!text_selection_triggered_)
     34     return false;
     35 
     36   switch (gesture.type()) {
     37     case ui::ET_GESTURE_TAP: {
     38       client_->LongPress(gesture.time, gesture.x, gesture.y);
     39       break;
     40     }
     41     case ui::ET_GESTURE_SCROLL_BEGIN: {
     42       client_->Unselect();
     43       anchor_x_ = gesture.x;
     44       anchor_y_ = gesture.y;
     45       break;
     46     }
     47     case ui::ET_GESTURE_SCROLL_UPDATE: {
     48       // TODO(changwan): check if we can show handles on ET_GESTURE_SCROLL_END
     49       // instead. Currently it is not possible as ShowSelectionHandles should
     50       // be called before we change the selection.
     51       client_->ShowSelectionHandlesAutomatically();
     52       client_->SelectRange(anchor_x_, anchor_y_, gesture.x, gesture.y);
     53       break;
     54     }
     55     default:
     56       // Suppress all other gestures when we are selecting text.
     57       break;
     58   }
     59   return true;
     60 }
     61 
     62 // static
     63 bool GestureTextSelector::ShouldStartTextSelection(
     64     const ui::MotionEvent& event) {
     65   DCHECK_GT(event.GetPointerCount(), 0u);
     66   // Currently we are supporting stylus-only cases.
     67   const bool is_stylus =
     68       event.GetToolType(0) == ui::MotionEvent::TOOL_TYPE_STYLUS;
     69   const bool is_only_secondary_button_pressed =
     70       event.GetButtonState() == ui::MotionEvent::BUTTON_SECONDARY;
     71   return is_stylus && is_only_secondary_button_pressed;
     72 }
     73 
     74 }  // namespace content
     75