layer.h revision 0529e5d033099cbfc42635f6f6183833b09dff6e 
1// Copyright 2010 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_LAYER_H_
6#define CC_LAYERS_LAYER_H_
7
8#include <set>
9#include <string>
10
11#include "base/callback.h"
12#include "base/memory/ref_counted.h"
13#include "base/observer_list.h"
14#include "cc/animation/layer_animation_controller.h"
15#include "cc/animation/layer_animation_value_observer.h"
16#include "cc/animation/layer_animation_value_provider.h"
17#include "cc/base/cc_export.h"
18#include "cc/base/region.h"
19#include "cc/base/scoped_ptr_vector.h"
20#include "cc/debug/micro_benchmark.h"
21#include "cc/layers/draw_properties.h"
22#include "cc/layers/layer_lists.h"
23#include "cc/layers/layer_position_constraint.h"
24#include "cc/layers/paint_properties.h"
25#include "cc/layers/render_surface.h"
26#include "cc/output/filter_operations.h"
27#include "skia/ext/refptr.h"
28#include "third_party/skia/include/core/SkColor.h"
29#include "third_party/skia/include/core/SkImageFilter.h"
30#include "third_party/skia/include/core/SkPicture.h"
31#include "third_party/skia/include/core/SkXfermode.h"
32#include "ui/gfx/rect.h"
33#include "ui/gfx/rect_f.h"
34#include "ui/gfx/transform.h"
35
36namespace gfx {
37class BoxF;
38}
39
40namespace base {
41namespace debug {
42class ConvertableToTraceFormat;
43}
44}
45
46namespace cc {
47
48class Animation;
49class AnimationDelegate;
50struct AnimationEvent;
51class CopyOutputRequest;
52class LayerAnimationDelegate;
53class LayerAnimationEventObserver;
54class LayerClient;
55class LayerImpl;
56class LayerTreeHost;
57class LayerTreeImpl;
58class PriorityCalculator;
59class RenderingStatsInstrumentation;
60class ResourceUpdateQueue;
61class ScrollbarLayerInterface;
62struct AnimationEvent;
63template <typename LayerType>
64class OcclusionTracker;
65
66// Base class for composited layers. Special layer types are derived from
67// this class.
68class CC_EXPORT Layer : public base::RefCounted<Layer>,
69                        public LayerAnimationValueObserver,
70                        public LayerAnimationValueProvider {
71 public:
72  typedef RenderSurfaceLayerList RenderSurfaceListType;
73  typedef LayerList LayerListType;
74  typedef RenderSurface RenderSurfaceType;
75
76  enum LayerIdLabels {
77    INVALID_ID = -1,
78  };
79
80  static scoped_refptr<Layer> Create();
81
82  int id() const { return layer_id_; }
83
84  Layer* RootLayer();
85  Layer* parent() { return parent_; }
86  const Layer* parent() const { return parent_; }
87  void AddChild(scoped_refptr<Layer> child);
88  void InsertChild(scoped_refptr<Layer> child, size_t index);
89  void ReplaceChild(Layer* reference, scoped_refptr<Layer> new_layer);
90  void RemoveFromParent();
91  void RemoveAllChildren();
92  void SetChildren(const LayerList& children);
93  bool HasAncestor(const Layer* ancestor) const;
94
95  const LayerList& children() const { return children_; }
96  Layer* child_at(size_t index) { return children_[index].get(); }
97
98  // This requests the layer and its subtree be rendered and given to the
99  // callback. If the copy is unable to be produced (the layer is destroyed
100  // first), then the callback is called with a NULL/empty result.
101  void RequestCopyOfOutput(scoped_ptr<CopyOutputRequest> request);
102  bool HasCopyRequest() const {
103    return !copy_requests_.empty();
104  }
105
106  void SetAnchorPoint(const gfx::PointF& anchor_point);
107  gfx::PointF anchor_point() const { return anchor_point_; }
108
109  void SetAnchorPointZ(float anchor_point_z);
110  float anchor_point_z() const { return anchor_point_z_; }
111
112  virtual void SetBackgroundColor(SkColor background_color);
113  SkColor background_color() const { return background_color_; }
114  // If contents_opaque(), return an opaque color else return a
115  // non-opaque color.  Tries to return background_color(), if possible.
116  SkColor SafeOpaqueBackgroundColor() const;
117
118  // A layer's bounds are in logical, non-page-scaled pixels (however, the
119  // root layer's bounds are in physical pixels).
120  void SetBounds(const gfx::Size& bounds);
121  gfx::Size bounds() const { return bounds_; }
122
123  void SetMasksToBounds(bool masks_to_bounds);
124  bool masks_to_bounds() const { return masks_to_bounds_; }
125
126  void SetMaskLayer(Layer* mask_layer);
127  Layer* mask_layer() { return mask_layer_.get(); }
128  const Layer* mask_layer() const { return mask_layer_.get(); }
129
130  virtual void SetNeedsDisplayRect(const gfx::RectF& dirty_rect);
131  void SetNeedsDisplay() { SetNeedsDisplayRect(gfx::RectF(bounds())); }
132
133  void SetOpacity(float opacity);
134  float opacity() const { return opacity_; }
135  bool OpacityIsAnimating() const;
136  virtual bool OpacityCanAnimateOnImplThread() const;
137
138  void SetBlendMode(SkXfermode::Mode blend_mode);
139  SkXfermode::Mode blend_mode() const { return blend_mode_; }
140
141  bool uses_default_blend_mode() const {
142    return blend_mode_ == SkXfermode::kSrcOver_Mode;
143  }
144
145  // A layer is root for an isolated group when it and all its descendants are
146  // drawn over a black and fully transparent background, creating an isolated
147  // group. It should be used along with SetBlendMode(), in order to restrict
148  // layers within the group to blend with layers outside this group.
149  void SetIsRootForIsolatedGroup(bool root);
150  bool is_root_for_isolated_group() const {
151    return is_root_for_isolated_group_;
152  }
153
154  void SetFilters(const FilterOperations& filters);
155  const FilterOperations& filters() const { return filters_; }
156  bool FilterIsAnimating() const;
157
158  // Background filters are filters applied to what is behind this layer, when
159  // they are viewed through non-opaque regions in this layer. They are used
160  // through the WebLayer interface, and are not exposed to HTML.
161  void SetBackgroundFilters(const FilterOperations& filters);
162  const FilterOperations& background_filters() const {
163    return background_filters_;
164  }
165
166  virtual void SetContentsOpaque(bool opaque);
167  bool contents_opaque() const { return contents_opaque_; }
168
169  void SetPosition(const gfx::PointF& position);
170  gfx::PointF position() const { return position_; }
171
172  void SetIsContainerForFixedPositionLayers(bool container);
173  bool IsContainerForFixedPositionLayers() const;
174
175  void SetPositionConstraint(const LayerPositionConstraint& constraint);
176  const LayerPositionConstraint& position_constraint() const {
177    return position_constraint_;
178  }
179
180  void SetTransform(const gfx::Transform& transform);
181  const gfx::Transform& transform() const { return transform_; }
182  bool TransformIsAnimating() const;
183  bool transform_is_invertible() const { return transform_is_invertible_; }
184
185  void SetScrollParent(Layer* parent);
186
187  Layer* scroll_parent() { return scroll_parent_; }
188  const Layer* scroll_parent() const { return scroll_parent_; }
189
190  void AddScrollChild(Layer* child);
191  void RemoveScrollChild(Layer* child);
192
193  std::set<Layer*>* scroll_children() { return scroll_children_.get(); }
194  const std::set<Layer*>* scroll_children() const {
195    return scroll_children_.get();
196  }
197
198  void SetClipParent(Layer* ancestor);
199
200  Layer* clip_parent() { return clip_parent_; }
201  const Layer* clip_parent() const {
202    return clip_parent_;
203  }
204
205  void AddClipChild(Layer* child);
206  void RemoveClipChild(Layer* child);
207
208  std::set<Layer*>* clip_children() { return clip_children_.get(); }
209  const std::set<Layer*>* clip_children() const {
210    return clip_children_.get();
211  }
212
213  DrawProperties<Layer>& draw_properties() { return draw_properties_; }
214  const DrawProperties<Layer>& draw_properties() const {
215    return draw_properties_;
216  }
217
218  // The following are shortcut accessors to get various information from
219  // draw_properties_
220  const gfx::Transform& draw_transform() const {
221    return draw_properties_.target_space_transform;
222  }
223  const gfx::Transform& screen_space_transform() const {
224    return draw_properties_.screen_space_transform;
225  }
226  float draw_opacity() const { return draw_properties_.opacity; }
227  bool draw_opacity_is_animating() const {
228    return draw_properties_.opacity_is_animating;
229  }
230  bool draw_transform_is_animating() const {
231    return draw_properties_.target_space_transform_is_animating;
232  }
233  bool screen_space_transform_is_animating() const {
234    return draw_properties_.screen_space_transform_is_animating;
235  }
236  bool screen_space_opacity_is_animating() const {
237    return draw_properties_.screen_space_opacity_is_animating;
238  }
239  bool can_use_lcd_text() const { return draw_properties_.can_use_lcd_text; }
240  bool is_clipped() const { return draw_properties_.is_clipped; }
241  gfx::Rect clip_rect() const { return draw_properties_.clip_rect; }
242  gfx::Rect drawable_content_rect() const {
243    return draw_properties_.drawable_content_rect;
244  }
245  gfx::Rect visible_content_rect() const {
246    return draw_properties_.visible_content_rect;
247  }
248  Layer* render_target() {
249    DCHECK(!draw_properties_.render_target ||
250           draw_properties_.render_target->render_surface());
251    return draw_properties_.render_target;
252  }
253  const Layer* render_target() const {
254    DCHECK(!draw_properties_.render_target ||
255           draw_properties_.render_target->render_surface());
256    return draw_properties_.render_target;
257  }
258  RenderSurface* render_surface() const {
259    return draw_properties_.render_surface.get();
260  }
261  int num_unclipped_descendants() const {
262    return draw_properties_.num_unclipped_descendants;
263  }
264
265  void SetScrollOffset(gfx::Vector2d scroll_offset);
266  gfx::Vector2d scroll_offset() const { return scroll_offset_; }
267  void SetScrollOffsetFromImplSide(const gfx::Vector2d& scroll_offset);
268
269  void SetScrollClipLayerId(int clip_layer_id);
270  bool scrollable() const { return scroll_clip_layer_id_ != INVALID_ID; }
271
272  void SetUserScrollable(bool horizontal, bool vertical);
273  bool user_scrollable_horizontal() const {
274    return user_scrollable_horizontal_;
275  }
276  bool user_scrollable_vertical() const { return user_scrollable_vertical_; }
277
278  void SetShouldScrollOnMainThread(bool should_scroll_on_main_thread);
279  bool should_scroll_on_main_thread() const {
280    return should_scroll_on_main_thread_;
281  }
282
283  void SetHaveWheelEventHandlers(bool have_wheel_event_handlers);
284  bool have_wheel_event_handlers() const { return have_wheel_event_handlers_; }
285
286  void SetHaveScrollEventHandlers(bool have_scroll_event_handlers);
287  bool have_scroll_event_handlers() const {
288    return have_scroll_event_handlers_;
289  }
290
291  void SetNonFastScrollableRegion(const Region& non_fast_scrollable_region);
292  const Region& non_fast_scrollable_region() const {
293    return non_fast_scrollable_region_;
294  }
295
296  void SetTouchEventHandlerRegion(const Region& touch_event_handler_region);
297  const Region& touch_event_handler_region() const {
298    return touch_event_handler_region_;
299  }
300
301  void set_did_scroll_callback(const base::Closure& callback) {
302    did_scroll_callback_ = callback;
303  }
304
305  void SetDrawCheckerboardForMissingTiles(bool checkerboard);
306  bool draw_checkerboard_for_missing_tiles() const {
307    return draw_checkerboard_for_missing_tiles_;
308  }
309
310  void SetForceRenderSurface(bool force_render_surface);
311  bool force_render_surface() const { return force_render_surface_; }
312
313  gfx::Vector2d ScrollDelta() const { return gfx::Vector2d(); }
314  gfx::Vector2dF TotalScrollOffset() const {
315    // Floating point to match the LayerImpl version.
316    return scroll_offset() + ScrollDelta();
317  }
318
319  void SetDoubleSided(bool double_sided);
320  bool double_sided() const { return double_sided_; }
321
322  void SetShouldFlattenTransform(bool flatten);
323  bool should_flatten_transform() const { return should_flatten_transform_; }
324
325  void SetIs3dSorted(bool sorted);
326  bool is_3d_sorted() const { return is_3d_sorted_; }
327
328  void set_use_parent_backface_visibility(bool use) {
329    use_parent_backface_visibility_ = use;
330  }
331  bool use_parent_backface_visibility() const {
332    return use_parent_backface_visibility_;
333  }
334
335  virtual void SetLayerTreeHost(LayerTreeHost* host);
336
337  bool HasDelegatedContent() const { return false; }
338  bool HasContributingDelegatedRenderPasses() const { return false; }
339
340  void SetIsDrawable(bool is_drawable);
341
342  void SetHideLayerAndSubtree(bool hide);
343  bool hide_layer_and_subtree() const { return hide_layer_and_subtree_; }
344
345  void SetReplicaLayer(Layer* layer);
346  Layer* replica_layer() { return replica_layer_.get(); }
347  const Layer* replica_layer() const { return replica_layer_.get(); }
348
349  bool has_mask() const { return !!mask_layer_.get(); }
350  bool has_replica() const { return !!replica_layer_.get(); }
351  bool replica_has_mask() const {
352    return replica_layer_.get() &&
353           (mask_layer_.get() || replica_layer_->mask_layer_.get());
354  }
355
356  // These methods typically need to be overwritten by derived classes.
357  virtual bool DrawsContent() const;
358  virtual void SavePaintProperties();
359  // Returns true iff any resources were updated that need to be committed.
360  virtual bool Update(ResourceUpdateQueue* queue,
361                      const OcclusionTracker<Layer>* occlusion);
362  virtual bool NeedMoreUpdates();
363  virtual void SetIsMask(bool is_mask) {}
364  virtual void ReduceMemoryUsage() {}
365  virtual void OnOutputSurfaceCreated() {}
366
367  virtual scoped_refptr<base::debug::ConvertableToTraceFormat> TakeDebugInfo();
368
369  void SetLayerClient(LayerClient* client) { client_ = client; }
370
371  virtual void PushPropertiesTo(LayerImpl* layer);
372
373  void CreateRenderSurface();
374  void ClearRenderSurface();
375
376  // The contents scale converts from logical, non-page-scaled pixels to target
377  // pixels. The contents scale is 1 for the root layer as it is already in
378  // physical pixels. By default contents scale is forced to be 1 except for
379  // subclasses of ContentsScalingLayer.
380  float contents_scale_x() const { return draw_properties_.contents_scale_x; }
381  float contents_scale_y() const { return draw_properties_.contents_scale_y; }
382  gfx::Size content_bounds() const { return draw_properties_.content_bounds; }
383
384  virtual void CalculateContentsScale(float ideal_contents_scale,
385                                      float device_scale_factor,
386                                      float page_scale_factor,
387                                      float maximum_animation_contents_scale,
388                                      bool animating_transform_to_screen,
389                                      float* contents_scale_x,
390                                      float* contents_scale_y,
391                                      gfx::Size* content_bounds);
392
393  LayerTreeHost* layer_tree_host() { return layer_tree_host_; }
394  const LayerTreeHost* layer_tree_host() const { return layer_tree_host_; }
395
396  // Set the priority of all desired textures in this layer.
397  virtual void SetTexturePriorities(const PriorityCalculator& priority_calc) {}
398
399  bool AddAnimation(scoped_ptr<Animation> animation);
400  void PauseAnimation(int animation_id, double time_offset);
401  void RemoveAnimation(int animation_id);
402
403  LayerAnimationController* layer_animation_controller() {
404    return layer_animation_controller_.get();
405  }
406  void SetLayerAnimationControllerForTest(
407      scoped_refptr<LayerAnimationController> controller);
408
409  void set_layer_animation_delegate(AnimationDelegate* delegate) {
410    layer_animation_controller_->set_layer_animation_delegate(delegate);
411  }
412
413  bool HasActiveAnimation() const;
414
415  void AddLayerAnimationEventObserver(
416      LayerAnimationEventObserver* animation_observer);
417  void RemoveLayerAnimationEventObserver(
418      LayerAnimationEventObserver* animation_observer);
419
420  virtual Region VisibleContentOpaqueRegion() const;
421
422  virtual ScrollbarLayerInterface* ToScrollbarLayer();
423
424  gfx::Rect LayerRectToContentRect(const gfx::RectF& layer_rect) const;
425
426  virtual skia::RefPtr<SkPicture> GetPicture() const;
427
428  // Constructs a LayerImpl of the correct runtime type for this Layer type.
429  virtual scoped_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl);
430
431  bool NeedsDisplayForTesting() const { return !update_rect_.IsEmpty(); }
432  void ResetNeedsDisplayForTesting() { update_rect_ = gfx::RectF(); }
433
434  RenderingStatsInstrumentation* rendering_stats_instrumentation() const;
435
436  const PaintProperties& paint_properties() const {
437    return paint_properties_;
438  }
439
440  // The scale at which contents should be rastered, to match the scale at
441  // which they will drawn to the screen. This scale is a component of the
442  // contents scale but does not include page/device scale factors.
443  // TODO(danakj): This goes away when TiledLayer goes away.
444  void set_raster_scale(float scale) { raster_scale_ = scale; }
445  float raster_scale() const { return raster_scale_; }
446  bool raster_scale_is_unknown() const { return raster_scale_ == 0.f; }
447
448  virtual bool SupportsLCDText() const;
449
450  void SetNeedsPushProperties();
451  bool needs_push_properties() const { return needs_push_properties_; }
452  bool descendant_needs_push_properties() const {
453    return num_dependents_need_push_properties_ > 0;
454  }
455  void reset_needs_push_properties_for_testing() {
456    needs_push_properties_ = false;
457  }
458
459  virtual void RunMicroBenchmark(MicroBenchmark* benchmark);
460
461 protected:
462  friend class LayerImpl;
463  friend class TreeSynchronizer;
464  virtual ~Layer();
465
466  Layer();
467
468  // These SetNeeds functions are in order of severity of update:
469  //
470  // Called when this layer has been modified in some way, but isn't sure
471  // that it needs a commit yet.  It needs CalcDrawProperties and UpdateLayers
472  // before it knows whether or not a commit is required.
473  void SetNeedsUpdate();
474  // Called when a property has been modified in a way that the layer
475  // knows immediately that a commit is required.  This implies SetNeedsUpdate
476  // as well as SetNeedsPushProperties to push that property.
477  void SetNeedsCommit();
478  // Called when there's been a change in layer structure.  Implies both
479  // SetNeedsUpdate and SetNeedsCommit, but not SetNeedsPushProperties.
480  void SetNeedsFullTreeSync();
481
482  // Called when the next commit should wait until the pending tree is activated
483  // before finishing the commit and unblocking the main thread. Used to ensure
484  // unused resources on the impl thread are returned before commit completes.
485  void SetNextCommitWaitsForActivation();
486
487  // Called when the blend mode or filters have been changed.
488  void SetNeedsFilterContextIfNeeded();
489
490  void AddDependentNeedsPushProperties();
491  void RemoveDependentNeedsPushProperties();
492  bool parent_should_know_need_push_properties() const {
493    return needs_push_properties() || descendant_needs_push_properties();
494  }
495
496  bool IsPropertyChangeAllowed() const;
497
498  // If this layer has a scroll parent, it removes |this| from its list of
499  // scroll children.
500  void RemoveFromScrollTree();
501
502  // If this layer has a clip parent, it removes |this| from its list of clip
503  // children.
504  void RemoveFromClipTree();
505
506  void reset_raster_scale_to_unknown() { raster_scale_ = 0.f; }
507
508  // This flag is set when the layer needs to push properties to the impl
509  // side.
510  bool needs_push_properties_;
511
512  // The number of direct children or dependent layers that need to be recursed
513  // to in order for them or a descendent of them to push properties to the impl
514  // side.
515  int num_dependents_need_push_properties_;
516
517  // Tracks whether this layer may have changed stacking order with its
518  // siblings.
519  bool stacking_order_changed_;
520
521  // The update rect is the region of the compositor resource that was
522  // actually updated by the compositor. For layers that may do updating
523  // outside the compositor's control (i.e. plugin layers), this information
524  // is not available and the update rect will remain empty.
525  // Note this rect is in layer space (not content space).
526  gfx::RectF update_rect_;
527
528  scoped_refptr<Layer> mask_layer_;
529
530  int layer_id_;
531
532  // When true, the layer is about to perform an update. Any commit requests
533  // will be handled implicitly after the update completes.
534  bool ignore_set_needs_commit_;
535
536 private:
537  friend class base::RefCounted<Layer>;
538
539  void SetParent(Layer* layer);
540  bool DescendantIsFixedToContainerLayer() const;
541
542  // Returns the index of the child or -1 if not found.
543  int IndexOfChild(const Layer* reference);
544
545  // This should only be called from RemoveFromParent().
546  void RemoveChildOrDependent(Layer* child);
547
548  // LayerAnimationValueProvider implementation.
549  virtual gfx::Vector2dF ScrollOffsetForAnimation() const OVERRIDE;
550
551  // LayerAnimationValueObserver implementation.
552  virtual void OnFilterAnimated(const FilterOperations& filters) OVERRIDE;
553  virtual void OnOpacityAnimated(float opacity) OVERRIDE;
554  virtual void OnTransformAnimated(const gfx::Transform& transform) OVERRIDE;
555  virtual void OnScrollOffsetAnimated(
556      const gfx::Vector2dF& scroll_offset) OVERRIDE;
557  virtual void OnAnimationWaitingForDeletion() OVERRIDE;
558  virtual bool IsActive() const OVERRIDE;
559
560  LayerList children_;
561  Layer* parent_;
562
563  // Layer instances have a weak pointer to their LayerTreeHost.
564  // This pointer value is nil when a Layer is not in a tree and is
565  // updated via SetLayerTreeHost() if a layer moves between trees.
566  LayerTreeHost* layer_tree_host_;
567
568  scoped_refptr<LayerAnimationController> layer_animation_controller_;
569
570  // Layer properties.
571  gfx::Size bounds_;
572
573  gfx::Vector2d scroll_offset_;
574  // This variable indicates which ancestor layer (if any) whose size,
575  // transformed relative to this layer, defines the maximum scroll offset for
576  // this layer.
577  int scroll_clip_layer_id_;
578  bool should_scroll_on_main_thread_ : 1;
579  bool have_wheel_event_handlers_ : 1;
580  bool have_scroll_event_handlers_ : 1;
581  bool user_scrollable_horizontal_ : 1;
582  bool user_scrollable_vertical_ : 1;
583  bool is_root_for_isolated_group_ : 1;
584  bool is_container_for_fixed_position_layers_ : 1;
585  bool is_drawable_ : 1;
586  bool hide_layer_and_subtree_ : 1;
587  bool masks_to_bounds_ : 1;
588  bool contents_opaque_ : 1;
589  bool double_sided_ : 1;
590  bool should_flatten_transform_ : 1;
591  bool use_parent_backface_visibility_ : 1;
592  bool draw_checkerboard_for_missing_tiles_ : 1;
593  bool force_render_surface_ : 1;
594  bool is_3d_sorted_ : 1;
595  bool transform_is_invertible_ : 1;
596  Region non_fast_scrollable_region_;
597  Region touch_event_handler_region_;
598  gfx::PointF position_;
599  gfx::PointF anchor_point_;
600  SkColor background_color_;
601  float opacity_;
602  SkXfermode::Mode blend_mode_;
603  FilterOperations filters_;
604  FilterOperations background_filters_;
605  float anchor_point_z_;
606  LayerPositionConstraint position_constraint_;
607  Layer* scroll_parent_;
608  scoped_ptr<std::set<Layer*> > scroll_children_;
609
610  Layer* clip_parent_;
611  scoped_ptr<std::set<Layer*> > clip_children_;
612
613  gfx::Transform transform_;
614
615  // Replica layer used for reflections.
616  scoped_refptr<Layer> replica_layer_;
617
618  // Transient properties.
619  float raster_scale_;
620
621  LayerClient* client_;
622
623  ScopedPtrVector<CopyOutputRequest> copy_requests_;
624
625  base::Closure did_scroll_callback_;
626
627  DrawProperties<Layer> draw_properties_;
628
629  PaintProperties paint_properties_;
630
631  DISALLOW_COPY_AND_ASSIGN(Layer);
632};
633
634}  // namespace cc
635
636#endif  // CC_LAYERS_LAYER_H_
637