third_party/blink/renderer/core/page/scrolling/text_fragment_selector_generator.h

// Copyright 2020 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 THIRD_PARTY_BLINK_RENDERER_CORE_PAGE_SCROLLING_TEXT_FRAGMENT_SELECTOR_GENERATOR_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_PAGE_SCROLLING_TEXT_FRAGMENT_SELECTOR_GENERATOR_H_

#include "third_party/blink/public/mojom/link_to_text/link_to_text.mojom-blink.h"
#include "third_party/blink/renderer/core/editing/forward.h"
#include "third_party/blink/renderer/core/page/scrolling/text_fragment_finder.h"
#include "third_party/blink/renderer/core/page/scrolling/text_fragment_selector.h"
#include "third_party/blink/renderer/platform/mojo/heap_mojo_receiver.h"

namespace blink {

class LocalFrame;

// TextFragmentSelectorGenerator is responsible for generating text fragment
// selectors for the user selected text according to spec in
// https://github.com/WICG/scroll-to-text-fragment#proposed-solution.
// Generated selectors would be later used to highlight the same
// text if successfully parsed by |TextFragmentAnchor |. Generation will be
// triggered when users request "link to text" for the selected text.
class CORE_EXPORT TextFragmentSelectorGenerator final
    : public GarbageCollected<TextFragmentSelectorGenerator>,
      public TextFragmentFinder::Client,
      public blink::mojom::blink::TextFragmentSelectorProducer {
 public:
  explicit TextFragmentSelectorGenerator() = default;

  void BindTextFragmentSelectorProducer(
      mojo::PendingReceiver<mojom::blink::TextFragmentSelectorProducer>
          producer);

  // Sets the frame and range of the current selection.
  void UpdateSelection(LocalFrame* selection_frame,
                       const EphemeralRangeInFlatTree& selection_range);

  // blink::mojom::blink::TextFragmentSelectorProducer interface
  // Generates selector for current selection.
  void GenerateSelector(GenerateSelectorCallback callback) override;

  // TextFragmentFinder::Client interface
  void DidFindMatch(const EphemeralRangeInFlatTree& match,
                    const TextFragmentAnchorMetrics::Match match_metrics,
                    bool is_unique) override;

  // Notifies the results of |GenerateSelector|.
  void NotifySelectorReady(const TextFragmentSelector& selector);

  // Releases members if necessary.
  void ClearSelection();

  void Trace(Visitor*) const;

 private:
  Member<LocalFrame> selection_frame_;
  Member<Range> selection_range_;
  std::unique_ptr<TextFragmentSelector> selector_;

  // Used for communication between |TextFragmentSelectorGenerator| in renderer
  // and |TextFragmentSelectorClientImpl| in browser.
  HeapMojoReceiver<blink::mojom::blink::TextFragmentSelectorProducer,
                   TextFragmentSelectorGenerator>
      selector_producer_{this, nullptr};
  GenerateSelectorCallback pending_generate_selector_callback_;

  DISALLOW_COPY_AND_ASSIGN(TextFragmentSelectorGenerator);
};

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_PAGE_SCROLLING_TEXT_FRAGMENT_SELECTOR_GENERATOR_H_