third_party/WebKit/public/web/WebViewClient.h

/*
 * Copyright (C) 2009 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef WebViewClient_h
#define WebViewClient_h

#include "WebAXEnums.h"
#include "WebFrame.h"
#include "WebPopupType.h"
#include "WebTextDirection.h"
#include "WebWidgetClient.h"
#include "public/platform/WebString.h"
#include "third_party/WebKit/common/page/page_visibility_state.mojom-shared.h"

namespace blink {

class WebDateTimeChooserCompletion;
class WebFileChooserCompletion;
class WebNode;
class WebSpeechRecognizer;
class WebURL;
class WebURLRequest;
class WebView;
class WebWidget;
enum class WebSandboxFlags;
struct WebDateTimeChooserParams;
struct WebRect;
struct WebSize;
struct WebWindowFeatures;

// Since a WebView is a WebWidget, a WebViewClient is a WebWidgetClient.
// Virtual inheritance allows an implementation of WebWidgetClient to be
// easily reused as part of an implementation of WebViewClient.
class WebViewClient : protected WebWidgetClient {
 public:
  ~WebViewClient() override = default;
  // Factory methods -----------------------------------------------------

  // Create a new related WebView.  This method must clone its session storage
  // so any subsequent calls to createSessionStorageNamespace conform to the
  // WebStorage specification.
  // The request parameter is only for the client to check if the request
  // could be fulfilled.  The client should not load the request.
  // The policy parameter indicates how the new view will be displayed in
  // WebWidgetClient::show.
  virtual WebView* CreateView(WebLocalFrame* creator,
                              const WebURLRequest& request,
                              const WebWindowFeatures& features,
                              const WebString& name,
                              WebNavigationPolicy policy,
                              bool suppress_opener,
                              WebSandboxFlags) {
    return nullptr;
  }

  // Create a new popup WebWidget.
  virtual WebWidget* CreatePopup(WebLocalFrame*, WebPopupType) {
    return nullptr;
  }

  // Returns the session storage namespace id associated with this WebView.
  virtual int64_t GetSessionStorageNamespaceId() { return 0; }

  // Misc ----------------------------------------------------------------

  // Called when script in the page calls window.print().  If frame is
  // non-null, then it selects a particular frame, including its
  // children, to print.  Otherwise, the main frame and its children
  // should be printed.
  virtual void PrintPage(WebLocalFrame*) {}

  // This method enumerates all the files in the path. It returns immediately
  // and asynchronously invokes the WebFileChooserCompletion with all the
  // files in the directory. Returns false if the WebFileChooserCompletion
  // will never be called.
  virtual bool EnumerateChosenDirectory(const WebString& path,
                                        WebFileChooserCompletion*) {
    return false;
  }

  // Called when PageImportanceSignals for the WebView is updated.
  virtual void PageImportanceSignalsChanged() {}

  // Called to get the position of the root window containing the widget
  // in screen coordinates.
  virtual WebRect RootWindowRect() { return WebRect(); }

  // Dialogs -------------------------------------------------------------

  // Ask users to choose date/time for the specified parameters. When a user
  // chooses a value, an implementation of this function should call
  // WebDateTimeChooserCompletion::didChooseValue or didCancelChooser. If the
  // implementation opened date/time chooser UI successfully, it should return
  // true. This function is used only if ExternalDateTimeChooser is used.
  virtual bool OpenDateTimeChooser(const WebDateTimeChooserParams&,
                                   WebDateTimeChooserCompletion*) {
    return false;
  }

  // UI ------------------------------------------------------------------

  // Called when hovering over an anchor with the given URL.
  virtual void SetMouseOverURL(const WebURL&) {}

  // Called when keyboard focus switches to an anchor with the given URL.
  virtual void SetKeyboardFocusURL(const WebURL&) {}

  // Called to determine if drag-n-drop operations may initiate a page
  // navigation.
  virtual bool AcceptsLoadDrops() { return true; }

  // Take focus away from the WebView by focusing an adjacent UI element
  // in the containing window.
  virtual void FocusNext() {}
  virtual void FocusPrevious() {}

  // Called when a new node gets focused. |fromNode| is the previously focused
  // node, |toNode| is the newly focused node. Either can be null.
  virtual void FocusedNodeChanged(const WebNode& from_node,
                                  const WebNode& to_node) {}

  // Called to check if layout update should be processed.
  virtual bool CanUpdateLayout() { return false; }

  // Indicates two things:
  //   1) This view may have a new layout now.
  //   2) Calling layout() is a no-op.
  // After calling WebWidget::layout(), expect to get this notification
  // unless the view did not need a layout.
  virtual void DidUpdateLayout() {}

  // Return true to swallow the input event if the embedder will start a
  // disambiguation popup
  virtual bool DidTapMultipleTargets(const WebSize& visual_viewport_offset,
                                     const WebRect& touch_rect,
                                     const WebVector<WebRect>& target_rects) {
    return false;
  }

  // Returns comma separated list of accept languages.
  virtual WebString AcceptLanguages() { return WebString(); }

  // Called when the View has changed size as a result of an auto-resize.
  virtual void DidAutoResize(const WebSize& new_size) {}

  // Called when the View acquires focus.
  virtual void DidFocus(WebLocalFrame* calling_frame) {}

  // Session history -----------------------------------------------------

  // Tells the embedder to navigate back or forward in session history by
  // the given offset (relative to the current position in session
  // history).
  virtual void NavigateBackForwardSoon(int offset) {}

  // Returns the number of history items before/after the current
  // history item.
  virtual int HistoryBackListCount() { return 0; }
  virtual int HistoryForwardListCount() { return 0; }

  // Developer tools -----------------------------------------------------

  // Called to notify the client that the inspector's settings were
  // changed and should be saved.  See WebView::inspectorSettings.
  virtual void DidUpdateInspectorSettings() {}

  virtual void DidUpdateInspectorSetting(const WebString& key,
                                         const WebString& value) {}

  // Speech --------------------------------------------------------------

  // Access the embedder API for speech recognition services.
  virtual WebSpeechRecognizer* SpeechRecognizer() { return nullptr; }

  // Zoom ----------------------------------------------------------------

  // Informs the browser that the zoom levels for this frame have changed from
  // the default values.
  virtual void ZoomLimitsChanged(double minimum_level, double maximum_level) {}

  // Informs the browser that the page scale has changed.
  virtual void PageScaleFactorChanged() {}

  // Gestures -------------------------------------------------------------

  virtual bool CanHandleGestureEvent() { return false; }

  // TODO(lfg): These methods are only exposed through WebViewClient while we
  // refactor WebView to not inherit from WebWidget.
  // WebWidgetClient overrides.
  void CloseWidgetSoon() override {}
  void ConvertViewportToWindow(WebRect* rect) override {}
  void ConvertWindowToViewport(WebFloatRect* rect) override {}
  void DidHandleGestureEvent(const WebGestureEvent& event,
                             bool event_cancelled) override {}
  void DidOverscroll(const WebFloatSize& overscroll_delta,
                     const WebFloatSize& accumulated_overscroll,
                     const WebFloatPoint& position_in_viewport,
                     const WebFloatSize& velocity_in_viewport,
                     const WebOverscrollBehavior& behavior) override {}
  void HasTouchEventHandlers(bool) override {}
  WebLayerTreeView* InitializeLayerTreeView() override { return nullptr; }
  WebScreenInfo GetScreenInfo() override { return WebScreenInfo(); }
  void SetTouchAction(WebTouchAction touch_action) override {}
  void ShowUnhandledTapUIIfNeeded(const WebTappedInfo& tapped_info) override {}
  void Show(WebNavigationPolicy) override {}
  virtual WebWidgetClient* WidgetClient() { return this; }

 protected:
};

}  // namespace blink

#endif