chrome/browser/ash/input_method/multi_word_suggester.h - chromium/src - Git at Google

 // Copyright 2021 The Chromium Authors
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #ifndef CHROME_BROWSER_ASH_INPUT_METHOD_MULTI_WORD_SUGGESTER_H_
 #define CHROME_BROWSER_ASH_INPUT_METHOD_MULTI_WORD_SUGGESTER_H_

 #include <optional>

 #include "base/memory/raw_ptr.h"
 #include "base/time/time.h"
 #include "chrome/browser/ash/input_method/suggester.h"
 #include "chrome/browser/ash/input_method/suggestion_enums.h"
 #include "chrome/browser/ash/input_method/suggestion_handler_interface.h"
 #include "chromeos/ash/services/ime/public/cpp/assistive_suggestions.h"

 namespace ash {
 namespace input_method {

 // Integrates multi word suggestions produced by the system with the assistive
 // framework. Handles showing / accepting / dismissing any multi word
 // suggestions generated by the system.
 class MultiWordSuggester : public Suggester {
  public:
   // `suggestion_handler` and `profile` need to exist longer than the lifetime
   // of this object.
   MultiWordSuggester(SuggestionHandlerInterface* suggestion_handler,
                      Profile* profile);
   ~MultiWordSuggester() override;

   // Suggester overrides:
   void OnFocus(int context_id) override;
   void OnBlur() override;
   void OnExternalSuggestionsUpdated(
       const std::vector<ime::AssistiveSuggestion>& suggestions,
       const std::optional<ime::SuggestionsTextContext>& context) override;
   SuggestionStatus HandleKeyEvent(const ui::KeyEvent& event) override;
   bool TrySuggestWithSurroundingText(const std::u16string& text,
                                      gfx::Range selection_range) override;
   bool AcceptSuggestion(size_t index = 0) override;
   void DismissSuggestion() override;
   AssistiveType GetProposeActionType() override;
   bool HasSuggestions() override;
   std::vector<ime::AssistiveSuggestion> GetSuggestions() override;

   // Used to capture any changes to the current input text.
   void OnSurroundingTextChanged(const std::u16string& text,
                                 gfx::Range selection_range);

  private:
   // Used to capture any internal state around the previously or currently
   // shown suggestions.
   class SuggestionState {
    public:
     enum State {
       kNoSuggestionShown,
       kPredictionSuggestionShown,
       kCompletionSuggestionShown,
       kTrackingLastSuggestionShown,
       kSuggestionDismissed,
       kSuggestionAccepted,
     };

     struct Suggestion {
       ime::AssistiveSuggestionMode mode;
       std::u16string text;
       size_t confirmed_length;
       size_t initial_confirmed_length;
       base::TimeTicks time_first_shown;
       bool highlighted = false;
       size_t original_surrounding_text_length;
     };

     struct SurroundingText {
       std::u16string text;
       size_t cursor_pos;
       size_t prev_cursor_pos;
       bool cursor_at_end_of_text;
     };

     explicit SuggestionState(MultiWordSuggester* suggester);
     ~SuggestionState();

     // As the name suggests, used to update the current state and perform
     // any actions required during a transition.
     void UpdateState(const State& state);

     // Captures surrounding text context.
     void UpdateSurroundingText(const SurroundingText& surrounding_text);

     // Captures new suggestion context.
     void UpdateSuggestion(const Suggestion& suggestion,
                           bool new_tracking_behavior);

     // Validates the given suggestion text context with the current surrounding
     // text, and returns the state of the given suggestion context.
     MultiWordSuggestionState ValidateSuggestion(
         const Suggestion& suggestion,
         const ime::SuggestionsTextContext& context);

     // Takes the current suggestion and surrounding text state, and ensures the
     // confirmed length or any other suggestion details are correct.
     void ReconcileSuggestionWithText();

     // Toggles the highlight state of the current suggeston.
     void ToggleSuggestionHighlight();

     // As the name suggests, is there a suggestion currently shown to the user?
     bool IsSuggestionShowing();

     // Is the user's cursor located at the end of the text they are currently
     // editing?
     bool IsCursorAtEndOfText();

     // Has the user highlighted the current suggestion showing?
     bool IsSuggestionHighlighted();

     // Returns the current suggestion state if there is any available.
     std::optional<Suggestion> GetSuggestion();

     // Returns the last suggestion type shown to the user. This suggestion may,
     // or may not, be currently showing to the user.
     AssistiveType GetLastSuggestionType();

     // Resets the current suggestion context, and any other related state.
     void ResetSuggestion();

    private:
     // Not owned by this class
     raw_ptr<MultiWordSuggester> suggester_;

     // The current state of the suggester (eg is a suggestion shown or not).
     State state_ = State::kNoSuggestionShown;

     // Last known surrounding text context captured by the suggester.
     std::optional<SurroundingText> surrounding_text_;

     // The current suggestion shown to the user by the suggester.
     std::optional<Suggestion> suggestion_;

     // The last suggestion type shown to the user.
     AssistiveType last_suggestion_type_ = AssistiveType::kGenericAction;
   };

   void DisplaySuggestionIfAvailable();
   void DisplaySuggestion(const SuggestionState::Suggestion& suggestion);
   void ResetSuggestionState();
   void ResetTextState();

   // Visibly highlight the suggestion in the ui shown to the user.
   void SetSuggestionHighlight(bool highlighted);

   // Announce the given message to the user.
   void Announce(const std::u16string& message);

   // The currently focused input (nullopt if none are focused)
   std::optional<int> focused_context_id_;

   // Not owned by this class
   raw_ptr<SuggestionHandlerInterface, DanglingUntriaged> suggestion_handler_;

   // Current suggestion state
   SuggestionState state_;

   ui::ime::AssistiveWindowButton suggestion_button_;

   // The current user's Chrome user profile.
   const raw_ptr<Profile> profile_;
 };

 }  // namespace input_method
 }  // namespace ash

 #endif  // CHROME_BROWSER_ASH_INPUT_METHOD_MULTI_WORD_SUGGESTER_H_
	// Copyright 2021 The Chromium Authors
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#ifndef CHROME_BROWSER_ASH_INPUT_METHOD_MULTI_WORD_SUGGESTER_H_
	#define CHROME_BROWSER_ASH_INPUT_METHOD_MULTI_WORD_SUGGESTER_H_

	#include <optional>

	#include "base/memory/raw_ptr.h"
	#include "base/time/time.h"
	#include "chrome/browser/ash/input_method/suggester.h"
	#include "chrome/browser/ash/input_method/suggestion_enums.h"
	#include "chrome/browser/ash/input_method/suggestion_handler_interface.h"
	#include "chromeos/ash/services/ime/public/cpp/assistive_suggestions.h"

	namespace ash {
	namespace input_method {

	// Integrates multi word suggestions produced by the system with the assistive
	// framework. Handles showing / accepting / dismissing any multi word
	// suggestions generated by the system.
	class MultiWordSuggester : public Suggester {
	public:
	// `suggestion_handler` and `profile` need to exist longer than the lifetime
	// of this object.
	MultiWordSuggester(SuggestionHandlerInterface* suggestion_handler,
	Profile* profile);
	~MultiWordSuggester() override;

	// Suggester overrides:
	void OnFocus(int context_id) override;
	void OnBlur() override;
	void OnExternalSuggestionsUpdated(
	const std::vector<ime::AssistiveSuggestion>& suggestions,
	const std::optional<ime::SuggestionsTextContext>& context) override;
	SuggestionStatus HandleKeyEvent(const ui::KeyEvent& event) override;
	bool TrySuggestWithSurroundingText(const std::u16string& text,
	gfx::Range selection_range) override;
	bool AcceptSuggestion(size_t index = 0) override;
	void DismissSuggestion() override;
	AssistiveType GetProposeActionType() override;
	bool HasSuggestions() override;
	std::vector<ime::AssistiveSuggestion> GetSuggestions() override;

	// Used to capture any changes to the current input text.
	void OnSurroundingTextChanged(const std::u16string& text,
	gfx::Range selection_range);

	private:
	// Used to capture any internal state around the previously or currently
	// shown suggestions.
	class SuggestionState {
	public:
	enum State {
	kNoSuggestionShown,
	kPredictionSuggestionShown,
	kCompletionSuggestionShown,
	kTrackingLastSuggestionShown,
	kSuggestionDismissed,
	kSuggestionAccepted,
	};

	struct Suggestion {
	ime::AssistiveSuggestionMode mode;
	std::u16string text;
	size_t confirmed_length;
	size_t initial_confirmed_length;
	base::TimeTicks time_first_shown;
	bool highlighted = false;
	size_t original_surrounding_text_length;
	};

	struct SurroundingText {
	std::u16string text;
	size_t cursor_pos;
	size_t prev_cursor_pos;
	bool cursor_at_end_of_text;
	};

	explicit SuggestionState(MultiWordSuggester* suggester);
	~SuggestionState();

	// As the name suggests, used to update the current state and perform
	// any actions required during a transition.
	void UpdateState(const State& state);

	// Captures surrounding text context.
	void UpdateSurroundingText(const SurroundingText& surrounding_text);

	// Captures new suggestion context.
	void UpdateSuggestion(const Suggestion& suggestion,
	bool new_tracking_behavior);

	// Validates the given suggestion text context with the current surrounding
	// text, and returns the state of the given suggestion context.
	MultiWordSuggestionState ValidateSuggestion(
	const Suggestion& suggestion,
	const ime::SuggestionsTextContext& context);

	// Takes the current suggestion and surrounding text state, and ensures the
	// confirmed length or any other suggestion details are correct.
	void ReconcileSuggestionWithText();

	// Toggles the highlight state of the current suggeston.
	void ToggleSuggestionHighlight();

	// As the name suggests, is there a suggestion currently shown to the user?
	bool IsSuggestionShowing();

	// Is the user's cursor located at the end of the text they are currently
	// editing?
	bool IsCursorAtEndOfText();

	// Has the user highlighted the current suggestion showing?
	bool IsSuggestionHighlighted();

	// Returns the current suggestion state if there is any available.
	std::optional<Suggestion> GetSuggestion();

	// Returns the last suggestion type shown to the user. This suggestion may,
	// or may not, be currently showing to the user.
	AssistiveType GetLastSuggestionType();

	// Resets the current suggestion context, and any other related state.
	void ResetSuggestion();

	private:
	// Not owned by this class
	raw_ptr<MultiWordSuggester> suggester_;

	// The current state of the suggester (eg is a suggestion shown or not).
	State state_ = State::kNoSuggestionShown;

	// Last known surrounding text context captured by the suggester.
	std::optional<SurroundingText> surrounding_text_;

	// The current suggestion shown to the user by the suggester.
	std::optional<Suggestion> suggestion_;

	// The last suggestion type shown to the user.
	AssistiveType last_suggestion_type_ = AssistiveType::kGenericAction;
	};

	void DisplaySuggestionIfAvailable();
	void DisplaySuggestion(const SuggestionState::Suggestion& suggestion);
	void ResetSuggestionState();
	void ResetTextState();

	// Visibly highlight the suggestion in the ui shown to the user.
	void SetSuggestionHighlight(bool highlighted);

	// Announce the given message to the user.
	void Announce(const std::u16string& message);

	// The currently focused input (nullopt if none are focused)
	std::optional<int> focused_context_id_;

	// Not owned by this class
	raw_ptr<SuggestionHandlerInterface, DanglingUntriaged> suggestion_handler_;

	// Current suggestion state
	SuggestionState state_;

	ui::ime::AssistiveWindowButton suggestion_button_;

	// The current user's Chrome user profile.
	const raw_ptr<Profile> profile_;
	};

	} // namespace input_method
	} // namespace ash

	#endif // CHROME_BROWSER_ASH_INPUT_METHOD_MULTI_WORD_SUGGESTER_H_