ui/touch_selection/touch_handle_drawable_aura.cc

   1 // Copyright 2015 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 "ui/touch_selection/touch_handle_drawable_aura.h"
   6
   7 #include "ui/aura/window.h"
   8 #include "ui/aura/window_targeter.h"
   9 #include "ui/aura_extra/image_window_delegate.h"
  10 #include "ui/base/cursor/cursor.h"
  11 #include "ui/base/hit_test.h"
  12 #include "ui/base/resource/resource_bundle.h"
  13 #include "ui/events/event.h"
  14 #include "ui/gfx/canvas.h"
  15 #include "ui/gfx/geometry/rect_conversions.h"
  16 #include "ui/resources/grit/ui_resources.h"
  17
  18 namespace ui {
  19 namespace {
  20
  21 // The distance by which a handle image is offset from the focal point (i.e.
  22 // text baseline) downwards.
  23 const int kSelectionHandleVerticalVisualOffset = 2;
  24
  25 // The padding around the selection handle image can be used to extend the
  26 // handle window so that touch events near the selection handle image are
  27 // targeted to the selection handle window.
  28 const int kSelectionHandlePadding = 0;
  29
  30 // Epsilon value used to compare float values to zero.
  31 const float kEpsilon = 1e-8f;
  32
  33 // Returns the appropriate handle image based on the handle orientation.
  34 gfx::Image* GetHandleImage(TouchHandleOrientation orientation) {
  35   int resource_id = 0;
  36   switch (orientation) {
  37     case TouchHandleOrientation::LEFT:
  38       resource_id = IDR_TEXT_SELECTION_HANDLE_LEFT;
  39       break;
  40     case TouchHandleOrientation::CENTER:
  41       resource_id = IDR_TEXT_SELECTION_HANDLE_CENTER;
  42       break;
  43     case TouchHandleOrientation::RIGHT:
  44       resource_id = IDR_TEXT_SELECTION_HANDLE_RIGHT;
  45       break;
  46     case TouchHandleOrientation::UNDEFINED:
  47       NOTREACHED() << "Invalid touch handle bound type.";
  48       return nullptr;
  49   };
  50   return &ResourceBundle::GetSharedInstance().GetImageNamed(resource_id);
  51 }
  52
  53 bool IsNearlyZero(float value) {
  54   return std::abs(value) < kEpsilon;
  55 }
  56
  57 }  // namespace
  58
  59 TouchHandleDrawableAura::TouchHandleDrawableAura(aura::Window* parent)
  60     : window_delegate_(new aura_extra::ImageWindowDelegate),
  61       window_(new aura::Window(window_delegate_)),
  62       enabled_(false),
  63       alpha_(0),
  64       orientation_(TouchHandleOrientation::UNDEFINED) {
  65   window_delegate_->set_image_offset(gfx::Vector2d(kSelectionHandlePadding,
  66                                                    kSelectionHandlePadding));
  67   window_delegate_->set_background_color(SK_ColorTRANSPARENT);
  68   window_->SetTransparent(true);
  69   window_->Init(LAYER_TEXTURED);
  70   window_->set_owned_by_parent(false);
  71   window_->set_ignore_events(true);
  72   parent->AddChild(window_.get());
  73 }
  74
  75 TouchHandleDrawableAura::~TouchHandleDrawableAura() {
  76 }
  77
  78 void TouchHandleDrawableAura::UpdateBounds() {
  79   gfx::RectF new_bounds = relative_bounds_;
  80   new_bounds.Offset(focal_position_.x(), focal_position_.y());
  81   window_->SetBounds(gfx::ToEnclosingRect(new_bounds));
  82 }
  83
  84 bool TouchHandleDrawableAura::IsVisible() const {
  85   return enabled_ && !IsNearlyZero(alpha_);
  86 }
  87
  88 void TouchHandleDrawableAura::SetEnabled(bool enabled) {
  89   if (enabled == enabled_)
  90     return;
  91
  92   enabled_ = enabled;
  93   if (IsVisible())
  94     window_->Show();
  95   else
  96     window_->Hide();
  97 }
  98
  99 void TouchHandleDrawableAura::SetOrientation(
 100     TouchHandleOrientation orientation) {
 101   if (orientation_ == orientation)
 102     return;
 103   orientation_ = orientation;
 104   gfx::Image* image = GetHandleImage(orientation);
 105   window_delegate_->SetImage(*image);
 106
 107   // Calculate the relative bounds.
 108   gfx::Size image_size = image->Size();
 109   int window_width = image_size.width() + 2 * kSelectionHandlePadding;
 110   int window_height = image_size.height() + 2 * kSelectionHandlePadding;
 111   // Due to the shape of the handle images, the window is aligned differently to
 112   // the selection bound depending on the orientation.
 113   int window_left = 0;
 114   switch (orientation) {
 115     case TouchHandleOrientation::LEFT:
 116       window_left = -image_size.width() - kSelectionHandlePadding;
 117       break;
 118     case TouchHandleOrientation::RIGHT:
 119       window_left = -kSelectionHandlePadding;
 120       break;
 121     case TouchHandleOrientation::CENTER:
 122       window_left = -window_width / 2;
 123       break;
 124     case TouchHandleOrientation::UNDEFINED:
 125       NOTREACHED() << "Undefined handle orientation.";
 126       break;
 127   };
 128   relative_bounds_ = gfx::RectF(
 129       window_left,
 130       kSelectionHandleVerticalVisualOffset - kSelectionHandlePadding,
 131       window_width,
 132       window_height);
 133   UpdateBounds();
 134 }
 135
 136 void TouchHandleDrawableAura::SetAlpha(float alpha) {
 137   if (alpha == alpha_)
 138     return;
 139
 140   alpha_ = alpha;
 141   window_->layer()->SetOpacity(alpha_);
 142   if (IsVisible())
 143     window_->Show();
 144   else
 145     window_->Hide();
 146 }
 147
 148 void TouchHandleDrawableAura::SetFocus(const gfx::PointF& position) {
 149   focal_position_ = position;
 150   UpdateBounds();
 151 }
 152
 153 gfx::RectF TouchHandleDrawableAura::GetVisibleBounds() const {
 154   gfx::RectF bounds(window_->bounds());
 155   bounds.Inset(kSelectionHandlePadding,
 156                kSelectionHandlePadding + kSelectionHandleVerticalVisualOffset,
 157                kSelectionHandlePadding,
 158                kSelectionHandlePadding);
 159   return bounds;
 160 }
 161
 162 }  // namespace ui