content/browser/renderer_host/render_widget_host_view_base.h

// Copyright (c) 2012 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.

#ifndef CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_BASE_H_
#define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_BASE_H_

#include <stddef.h>
#include <stdint.h>

#include <memory>
#include <string>
#include <vector>

#include "base/callback_forward.h"
#include "base/macros.h"
#include "base/observer_list.h"
#include "base/process/kill.h"
#include "base/strings/string16.h"
#include "base/timer/timer.h"
#include "build/build_config.h"
#include "cc/output/compositor_frame.h"
#include "cc/surfaces/surface_id.h"
#include "content/browser/renderer_host/event_with_latency_info.h"
#include "content/common/content_export.h"
#include "content/common/input/input_event_ack_state.h"
#include "content/public/browser/readback_types.h"
#include "content/public/browser/render_widget_host_view.h"
#include "content/public/common/screen_info.h"
#include "ipc/ipc_listener.h"
#include "third_party/WebKit/public/platform/modules/screen_orientation/WebScreenOrientationType.h"
#include "third_party/WebKit/public/web/WebPopupType.h"
#include "third_party/WebKit/public/web/WebTextDirection.h"
#include "third_party/skia/include/core/SkImageInfo.h"
#include "ui/base/ime/text_input_mode.h"
#include "ui/base/ime/text_input_type.h"
#include "ui/display/display.h"
#include "ui/gfx/geometry/rect.h"
#include "ui/gfx/native_widget_types.h"
#include "ui/gfx/range/range.h"
#include "ui/surface/transport_dib.h"

class SkBitmap;

struct AccessibilityHostMsg_EventParams;
struct ViewHostMsg_SelectionBounds_Params;

namespace media {
class VideoFrame;
}

namespace blink {
class WebMouseEvent;
class WebMouseWheelEvent;
}

namespace cc {
class SurfaceHittestDelegate;
}

namespace ui {
class LatencyInfo;
struct DidOverscrollParams;
}

namespace content {
class BrowserAccessibilityDelegate;
class BrowserAccessibilityManager;
class RenderWidgetHostImpl;
class RenderWidgetHostViewBaseObserver;
class SyntheticGesture;
class SyntheticGestureTarget;
class TextInputManager;
class WebCursor;
struct NativeWebKeyboardEvent;
struct TextInputState;

// Basic implementation shared by concrete RenderWidgetHostView subclasses.
class CONTENT_EXPORT RenderWidgetHostViewBase : public RenderWidgetHostView,
                                                public IPC::Listener {
 public:
  ~RenderWidgetHostViewBase() override;

  float current_device_scale_factor() const {
    return current_device_scale_factor_;
  }

  // Returns the focused RenderWidgetHost inside this |view|'s RWH.
  RenderWidgetHostImpl* GetFocusedWidget() const;

  // RenderWidgetHostView implementation.
  RenderWidgetHost* GetRenderWidgetHost() const override;
  void SetBackgroundColor(SkColor color) override;
  void SetBackgroundColorToDefault() final;
  bool GetBackgroundOpaque() override;
  ui::TextInputClient* GetTextInputClient() override;
  void WasUnOccluded() override {}
  void WasOccluded() override {}
  bool IsShowingContextMenu() const override;
  void SetShowingContextMenu(bool showing_menu) override;
  base::string16 GetSelectedText() override;
  bool IsMouseLocked() override;
  gfx::Size GetVisibleViewportSize() const override;
  void SetInsets(const gfx::Insets& insets) override;
  void BeginFrameSubscription(
      std::unique_ptr<RenderWidgetHostViewFrameSubscriber> subscriber) override;
  void EndFrameSubscription() override;
  void FocusedNodeTouched(const gfx::Point& location_dips_screen,
                          bool editable) override;

  // This only needs to be overridden by RenderWidgetHostViewBase subclasses
  // that handle content embedded within other RenderWidgetHostViews.
  gfx::Point TransformPointToRootCoordSpace(const gfx::Point& point) override;
  gfx::PointF TransformPointToRootCoordSpaceF(
      const gfx::PointF& point) override;

  // IPC::Listener implementation:
  bool OnMessageReceived(const IPC::Message& msg) override;

  void SetPopupType(blink::WebPopupType popup_type);

  blink::WebPopupType GetPopupType();

  // Return a value that is incremented each time the renderer swaps a new frame
  // to the view.
  uint32_t RendererFrameNumber();

  // Called each time the RenderWidgetHost receives a new frame for display from
  // the renderer.
  void DidReceiveRendererFrame();

  // Notification that a resize or move session ended on the native widget.
  void UpdateScreenInfo(gfx::NativeView view);

  // Tells if the display property (work area/scale factor) has
  // changed since the last time.
  bool HasDisplayPropertyChanged(gfx::NativeView view);

  // Called by the TextInputManager to notify the view about being removed from
  // the list of registered views, i.e., TextInputManager is no longer tracking
  // TextInputState from this view. The RWHV should reset |text_input_manager_|
  // to nullptr.
  void DidUnregisterFromTextInputManager(TextInputManager* text_input_manager);

  base::WeakPtr<RenderWidgetHostViewBase> GetWeakPtr();

  //----------------------------------------------------------------------------
  // The following methods can be overridden by derived classes.

  // Notifies the View that the renderer text selection has changed.
  virtual void SelectionChanged(const base::string16& text,
                                size_t offset,
                                const gfx::Range& range);

  // The requested size of the renderer. May differ from GetViewBounds().size()
  // when the view requires additional throttling.
  virtual gfx::Size GetRequestedRendererSize() const;

  // The size of the view's backing surface in non-DPI-adjusted pixels.
  virtual gfx::Size GetPhysicalBackingSize() const;

  // Whether or not Blink's viewport size should be shrunk by the height of the
  // URL-bar.
  virtual bool DoTopControlsShrinkBlinkSize() const;

  // The height of the URL-bar top controls.
  virtual float GetTopControlsHeight() const;

  // The height of the bottom bar.
  virtual float GetBottomControlsHeight() const;

  // Called prior to forwarding input event messages to the renderer, giving
  // the view a chance to perform in-process event filtering or processing.
  // Return values of |NOT_CONSUMED| or |UNKNOWN| will result in |input_event|
  // being forwarded.
  virtual InputEventAckState FilterInputEvent(
      const blink::WebInputEvent& input_event);

  // Called by the host when it requires an input flush; the flush call should
  // by synchronized with BeginFrame.
  virtual void OnSetNeedsFlushInput();

  virtual void WheelEventAck(const blink::WebMouseWheelEvent& event,
                             InputEventAckState ack_result);

  virtual void GestureEventAck(const blink::WebGestureEvent& event,
                               InputEventAckState ack_result);

  // Create a platform specific SyntheticGestureTarget implementation that will
  // be used to inject synthetic input events.
  virtual std::unique_ptr<SyntheticGestureTarget>
  CreateSyntheticGestureTarget();

  // Create a BrowserAccessibilityManager for a frame in this view.
  // If |for_root_frame| is true, creates a BrowserAccessibilityManager
  // suitable for the root frame, which may be linked to its native
  // window container.
  virtual BrowserAccessibilityManager* CreateBrowserAccessibilityManager(
      BrowserAccessibilityDelegate* delegate, bool for_root_frame);

  virtual void AccessibilityShowMenu(const gfx::Point& point);
  virtual gfx::Point AccessibilityOriginInScreen(const gfx::Rect& bounds);
  virtual gfx::AcceleratedWidget AccessibilityGetAcceleratedWidget();
  virtual gfx::NativeViewAccessible AccessibilityGetNativeViewAccessible();

  // Informs that the focused DOM node has changed.
  virtual void FocusedNodeChanged(bool is_editable_node,
                                  const gfx::Rect& node_bounds_in_screen) {}

  virtual void OnSwapCompositorFrame(uint32_t compositor_frame_sink_id,
                                     cc::CompositorFrame frame) {}

  // This method exists to allow removing of displayed graphics, after a new
  // page has been loaded, to prevent the displayed URL from being out of sync
  // with what is visible on screen.
  virtual void ClearCompositorFrame() = 0;

  // Because the associated remote WebKit instance can asynchronously
  // prevent-default on a dispatched touch event, the touch events are queued in
  // the GestureRecognizer until invocation of ProcessAckedTouchEvent releases
  // it to be consumed (when |ack_result| is NOT_CONSUMED OR NO_CONSUMER_EXISTS)
  // or ignored (when |ack_result| is CONSUMED).
  virtual void ProcessAckedTouchEvent(const TouchEventWithLatencyInfo& touch,
                                      InputEventAckState ack_result) {}

  virtual void DidOverscroll(const ui::DidOverscrollParams& params) {}

  virtual void DidStopFlinging() {}

  // Returns the compositing surface ID namespace, or 0 if Surfaces are not
  // enabled.
  virtual cc::FrameSinkId GetFrameSinkId();

  // When there are multiple RenderWidgetHostViews for a single page, input
  // events need to be targeted to the correct one for handling. The following
  // methods are invoked on the RenderWidgetHostView that should be able to
  // properly handle the event (i.e. it has focus for keyboard events, or has
  // been identified by hit testing mouse, touch or gesture events).
  virtual cc::FrameSinkId FrameSinkIdAtPoint(
      cc::SurfaceHittestDelegate* delegate,
      const gfx::Point& point,
      gfx::Point* transformed_point);
  virtual void ProcessKeyboardEvent(const NativeWebKeyboardEvent& event) {}
  virtual void ProcessMouseEvent(const blink::WebMouseEvent& event,
                                 const ui::LatencyInfo& latency) {}
  virtual void ProcessMouseWheelEvent(const blink::WebMouseWheelEvent& event,
                                      const ui::LatencyInfo& latency) {}
  virtual void ProcessTouchEvent(const blink::WebTouchEvent& event,
                                 const ui::LatencyInfo& latency) {}
  virtual void ProcessGestureEvent(const blink::WebGestureEvent& event,
                                   const ui::LatencyInfo& latency) {}

  // Transform a point that is in the coordinate space of a Surface that is
  // embedded within the RenderWidgetHostViewBase's Surface to the
  // coordinate space of an embedding, or embedded, Surface. Typically this
  // means that a point was received from an out-of-process iframe's
  // RenderWidget and needs to be translated to viewport coordinates for the
  // root RWHV, in which case this method is called on the root RWHV with the
  // out-of-process iframe's SurfaceId.
  // Returns false when this attempts to transform a point between coordinate
  // spaces of surfaces where one does not contain the other. To transform
  // between sibling surfaces, the point must be transformed to the root's
  // coordinate space as an intermediate step.
  virtual bool TransformPointToLocalCoordSpace(
      const gfx::Point& point,
      const cc::SurfaceId& original_surface,
      gfx::Point* transformed_point);

  // Transform a point that is in the coordinate space for the current
  // RenderWidgetHostView to the coordinate space of the target_view.
  virtual bool TransformPointToCoordSpaceForView(
      const gfx::Point& point,
      RenderWidgetHostViewBase* target_view,
      gfx::Point* transformed_point);

  // TODO(kenrb, wjmaclean): This is a temporary subclass identifier for
  // RenderWidgetHostViewGuests that is needed for special treatment during
  // input event routing. It can be removed either when RWHVGuests properly
  // support direct mouse event routing, or when RWHVGuest is removed
  // entirely, which comes first.
  virtual bool IsRenderWidgetHostViewGuest();

  // Subclass identifier for RenderWidgetHostViewChildFrames. This is useful
  // to be able to know if this RWHV is embedded within another RWHV. If
  // other kinds of embeddable RWHVs are created, this should be renamed to
  // a more generic term -- in which case, static casts to RWHVChildFrame will
  // need to also be resolved.
  virtual bool IsRenderWidgetHostViewChildFrame();

  //----------------------------------------------------------------------------
  // The following methods are related to IME.
  // TODO(ekaramad): Most of the IME methods should not stay virtual after IME
  // is implemented for OOPIF. After fixing IME, mark the corresponding methods
  // non-virtual (https://crbug.com/578168).

  // Updates the state of the input method attached to the view.
  virtual void TextInputStateChanged(const TextInputState& text_input_state);

  // Cancel the ongoing composition of the input method attached to the view.
  virtual void ImeCancelComposition();

  // Notifies the view that the renderer selection bounds has changed.
  // Selection bounds are described as a focus bound which is the current
  // position of caret on the screen, as well as the anchor bound which is the
  // starting position of the selection. The coordinates are with respect to
  // RenderWidget's window's origin. Focus and anchor bound are represented as
  // gfx::Rect.
  virtual void SelectionBoundsChanged(
      const ViewHostMsg_SelectionBounds_Params& params);

  // Updates the range of the marked text in an IME composition.
  virtual void ImeCompositionRangeChanged(
      const gfx::Range& range,
      const std::vector<gfx::Rect>& character_bounds);

  //----------------------------------------------------------------------------
  // The following pure virtual methods are implemented by derived classes.

  // Perform all the initialization steps necessary for this object to represent
  // a popup (such as a <select> dropdown), then shows the popup at |pos|.
  virtual void InitAsPopup(RenderWidgetHostView* parent_host_view,
                           const gfx::Rect& bounds) = 0;

  // Perform all the initialization steps necessary for this object to represent
  // a full screen window.
  // |reference_host_view| is the view associated with the creating page that
  // helps to position the full screen widget on the correct monitor.
  virtual void InitAsFullscreen(RenderWidgetHostView* reference_host_view) = 0;

  // Sets the cursor to the one associated with the specified cursor_type
  virtual void UpdateCursor(const WebCursor& cursor) = 0;

  // Indicates whether the page has finished loading.
  virtual void SetIsLoading(bool is_loading) = 0;

  // Notifies the View that the renderer has ceased to exist.
  virtual void RenderProcessGone(base::TerminationStatus status,
                                 int error_code) = 0;

  // Tells the View to destroy itself.
  virtual void Destroy() = 0;

  // Tells the View that the tooltip text for the current mouse position over
  // the page has changed.
  virtual void SetTooltipText(const base::string16& tooltip_text) = 0;

  // Copies the contents of the compositing surface, providing a new SkBitmap
  // result via an asynchronously-run |callback|. |src_subrect| is specified in
  // layer space coordinates for the current platform (e.g., DIP for Aura/Mac,
  // physical for Android), and is the region to be copied from this view. When
  // |src_subrect| is empty then the whole surface will be copied. The copy is
  // then scaled to a SkBitmap of size |dst_size|. If |dst_size| is empty then
  // output will be unscaled. |callback| is run with true on success,
  // false otherwise. A smaller region than |src_subrect| may be copied
  // if the underlying surface is smaller than |src_subrect|.
  virtual void CopyFromCompositingSurface(
      const gfx::Rect& src_subrect,
      const gfx::Size& dst_size,
      const ReadbackRequestCallback& callback,
      const SkColorType preferred_color_type) = 0;

  // Copies the contents of the compositing surface, populating the given
  // |target| with YV12 image data. |src_subrect| is specified in layer space
  // coordinates for the current platform (e.g., DIP for Aura/Mac, physical for
  // Android), and is the region to be copied from this view. The copy is then
  // scaled and letterboxed with black borders to fit |target|. Finally,
  // |callback| is asynchronously run with true/false for
  // success/failure. |target| must point to an allocated, YV12 video frame of
  // the intended size. This operation will fail if there is no available
  // compositing surface.
  virtual void CopyFromCompositingSurfaceToVideoFrame(
      const gfx::Rect& src_subrect,
      const scoped_refptr<media::VideoFrame>& target,
      const base::Callback<void(const gfx::Rect&, bool)>& callback) = 0;

  // Returns true if CopyFromCompositingSurfaceToVideoFrame() is likely to
  // succeed.
  //
  // TODO(nick): When VideoFrame copies are broadly implemented, this method
  // should be renamed to HasCompositingSurface(), or unified with
  // IsSurfaceAvailableForCopy() and HasAcceleratedSurface().
  virtual bool CanCopyToVideoFrame() const = 0;

  // Return true if the view has an accelerated surface that contains the last
  // presented frame for the view. If |desired_size| is non-empty, true is
  // returned only if the accelerated surface size matches.
  virtual bool HasAcceleratedSurface(const gfx::Size& desired_size) = 0;

  // Compute the orientation type of the display assuming it is a mobile device.
  static ScreenOrientationValues GetOrientationTypeForMobile(
      const display::Display& display);

  // Compute the orientation type of the display assuming it is a desktop.
  static ScreenOrientationValues GetOrientationTypeForDesktop(
      const display::Display& display);

  // Gets the bounds of the window, in screen coordinates.
  virtual gfx::Rect GetBoundsInRootWindow() = 0;

  // Called by the RenderWidgetHost when an ambiguous gesture is detected to
  // show the disambiguation popup bubble.
  virtual void ShowDisambiguationPopup(const gfx::Rect& rect_pixels,
                                       const SkBitmap& zoomed_bitmap);

  // Called by the WebContentsImpl when a user tries to navigate a new page on
  // main frame.
  virtual void OnDidNavigateMainFrameToNewPage();

  // Instructs the view to not drop the surface even when the view is hidden.
  virtual void LockCompositingSurface() = 0;
  virtual void UnlockCompositingSurface() = 0;

  // Add and remove observers for lifetime event notifications. The order in
  // which notifications are sent to observers is undefined. Clients must be
  // sure to remove the observer before they go away.
  void AddObserver(RenderWidgetHostViewBaseObserver* observer);
  void RemoveObserver(RenderWidgetHostViewBaseObserver* observer);

  // Returns a reference to the current instance of TextInputManager. The
  // reference is obtained from RenderWidgetHostDelegate. The first time a non-
  // null reference is obtained, its value is cached in |text_input_manager_|
  // and this view is registered with it. The RWHV will unregister from the
  // TextInputManager if it is destroyed or if the TextInputManager itself is
  // destroyed. The unregistration of the RWHV from TextInputManager is
  // necessary and must be done by explicitly calling
  // TextInputManager::Unregister.
  // It is safer to use this method rather than directly dereferencing
  // |text_input_manager_|.
  TextInputManager* GetTextInputManager();

  bool is_fullscreen() { return is_fullscreen_; }

  // Exposed for testing.
  virtual bool IsChildFrameForTesting() const;
  virtual cc::SurfaceId SurfaceIdForTesting() const;

 protected:
  // Interface class only, do not construct.
  RenderWidgetHostViewBase();

  void NotifyObserversAboutShutdown();

  // Is this a fullscreen view?
  bool is_fullscreen_;

  // Whether this view is a popup and what kind of popup it is (select,
  // autofill...).
  blink::WebPopupType popup_type_;

  // The background color of the web content.
  SkColor background_color_;

  // While the mouse is locked, the cursor is hidden from the user. Mouse events
  // are still generated. However, the position they report is the last known
  // mouse position just as mouse lock was entered; the movement they report
  // indicates what the change in position of the mouse would be had it not been
  // locked.
  bool mouse_locked_;

  // Whether we are showing a context menu.
  bool showing_context_menu_;

// TODO(ekaramad): In aura, text selection tracking for IME is done through the
// TextInputManager. We still need the following variables for other platforms.
// Remove them when tracking is done by TextInputManager on all platforms
// (https://crbug.com/578168 and https://crbug.com/602427).
#if !defined(USE_AURA)
  // A buffer containing the text inside and around the current selection range.
  base::string16 selection_text_;

  // The offset of the text stored in |selection_text_| relative to the start of
  // the web page.
  size_t selection_text_offset_;

  // The current selection range relative to the start of the web page.
  gfx::Range selection_range_;
#endif

  // The scale factor of the display the renderer is currently on.
  float current_device_scale_factor_;

  // The orientation of the display the renderer is currently on.
  display::Display::Rotation current_display_rotation_;

  // A reference to current TextInputManager instance this RWHV is registered
  // with. This is initially nullptr until the first time the view calls
  // GetTextInputManager(). It also becomes nullptr when TextInputManager is
  // destroyed before the RWHV is destroyed.
  TextInputManager* text_input_manager_;

 private:
  void FlushInput();

  gfx::Rect current_display_area_;

  uint32_t renderer_frame_number_;

  base::OneShotTimer flush_input_timer_;

  base::ObserverList<RenderWidgetHostViewBaseObserver> observers_;

  base::WeakPtrFactory<RenderWidgetHostViewBase> weak_factory_;

  DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewBase);
};

}  // namespace content

#endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_BASE_H_