cc/layers/scrollbar_layer_impl_base.h

   1 // Copyright 2013 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 #ifndef CC_LAYERS_SCROLLBAR_LAYER_IMPL_BASE_H_
   6 #define CC_LAYERS_SCROLLBAR_LAYER_IMPL_BASE_H_
   7
   8 #include "cc/base/cc_export.h"
   9 #include "cc/input/scrollbar.h"
  10 #include "cc/layers/layer.h"
  11 #include "cc/layers/layer_impl.h"
  12
  13 namespace cc {
  14
  15 class LayerTreeImpl;
  16
  17 class CC_EXPORT ScrollbarLayerImplBase : public LayerImpl {
  18  public:
  19   int ScrollLayerId() const {
  20     return scroll_layer_ ? scroll_layer_->id() : Layer::INVALID_ID;
  21   }
  22   int ClipLayerId() const {
  23     return clip_layer_ ? clip_layer_->id() : Layer::INVALID_ID;
  24   }
  25
  26   void SetScrollLayerAndClipLayerByIds(int scroll_layer_id, int clip_layer_id);
  27   void ClearScrollLayer() { scroll_layer_ = nullptr; }
  28   void ClearClipLayer() { clip_layer_ = nullptr; }
  29
  30   float current_pos() const { return current_pos_; }
  31   bool SetCurrentPos(float current_pos);
  32   int maximum() const { return maximum_; }
  33   bool SetMaximum(int maximum);
  34
  35   bool SetVerticalAdjust(float vertical_adjust);
  36
  37   bool is_overlay_scrollbar() const { return is_overlay_scrollbar_; }
  38   void set_is_overlay_scrollbar(bool is_overlay) {
  39     is_overlay_scrollbar_ = is_overlay;
  40   }
  41
  42   ScrollbarOrientation orientation() const { return orientation_; }
  43   bool is_left_side_vertical_scrollbar() {
  44     return is_left_side_vertical_scrollbar_;
  45   }
  46
  47   bool CanScrollOrientation() const;
  48
  49   void PushPropertiesTo(LayerImpl* layer) override;
  50   ScrollbarLayerImplBase* ToScrollbarLayer() override;
  51   void PushScrollClipPropertiesTo(LayerImpl* layer);
  52
  53   bool SetVisibleToTotalLengthRatio(float ratio);
  54   // Thumb quad rect in layer space.
  55   virtual gfx::Rect ComputeThumbQuadRect() const;
  56
  57   float thumb_thickness_scale_factor() {
  58     return thumb_thickness_scale_factor_;
  59   }
  60   bool SetThumbThicknessScaleFactor(float thumb_thickness_scale_factor);
  61
  62   void ScrollbarParametersDidChange(bool on_resize);
  63
  64  protected:
  65   ScrollbarLayerImplBase(LayerTreeImpl* tree_impl,
  66                          int id,
  67                          ScrollbarOrientation orientation,
  68                          bool is_left_side_vertical_scrollbar,
  69                          bool is_overlay);
  70   ~ScrollbarLayerImplBase() override;
  71
  72   float visible_to_total_length_ratio() const {
  73     return visible_to_total_length_ratio_;
  74   }
  75   float vertical_adjust() const { return vertical_adjust_; }
  76
  77   virtual int ThumbThickness() const = 0;
  78   virtual int ThumbLength() const = 0;
  79   virtual float TrackLength() const = 0;
  80   virtual int TrackStart() const = 0;
  81   // Indicates whether the thumb length can be changed without going back to the
  82   // main thread.
  83   virtual bool IsThumbResizable() const = 0;
  84
  85  private:
  86   LayerImpl* scroll_layer_;
  87   LayerImpl* clip_layer_;
  88   bool is_overlay_scrollbar_;
  89
  90   float thumb_thickness_scale_factor_;
  91   float current_pos_;
  92   int maximum_;
  93   ScrollbarOrientation orientation_;
  94   bool is_left_side_vertical_scrollbar_;
  95
  96   // Difference between the clip layer's height and the visible viewport
  97   // height (which may differ in the presence of top-controls hiding).
  98   float vertical_adjust_;
  99
 100   float visible_to_total_length_ratio_;
 101
 102   DISALLOW_COPY_AND_ASSIGN(ScrollbarLayerImplBase);
 103 };
 104
 105 }  // namespace cc
 106
 107 #endif  // CC_LAYERS_SCROLLBAR_LAYER_IMPL_BASE_H_