blob: d688e1cc0356a878749ec706708a6056072fab0d [file] [log] [blame]
// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <fuchsia/ui/input/cpp/fidl.h>
#include <fuchsia/ui/input3/cpp/fidl.h>
#include <fuchsia/ui/views/cpp/fidl.h>
#include <lib/fidl/cpp/binding.h>
#include <memory>
#include "src/embedder/engine/embedder.h"
#include "src/embedder/keyboard.h"
#include "src/embedder/logging.h"
namespace embedder {
/// The channel name used for text editing platofrm messages.
constexpr char kTextInputChannel[] = "flutter/textinput";
/// The channel name used for key event platform messages.
constexpr char kKeyEventChannel[] = "flutter/keyevent";
/// TextDelegate handles keyboard input and text editing.
/// It mediates between Fuchsia's input and Flutter's platform messages. When it
/// is initialized, it contacts `fuchsia.ui.input.Keyboard` to register itself
/// as listener of key events.
/// Whenever a text editing request comes from the
/// Flutter app, it will activate Fuchsia's input method editor, and will send
/// text edit actions coming from the Fuchsia platform over to the Flutter app,
/// by converting FIDL messages (`fuchsia.ui.input.InputMethodEditorClient`
/// calls) to appropriate text editing Flutter platform messages.
/// For details refer to:
/// * Flutter side:
/// * Fuchsia side:
/// TODO(naudzghebre):
/// 1. Handle 'flutter/keyevent' platform messages
/// 2. Handle 'flutter/textinput' platform messages
class TextDelegate : public fuchsia::ui::input3::KeyboardListener,
public fuchsia::ui::input::InputMethodEditorClient {
/// Creates a new TextDelegate.
/// Args:
/// view_ref: the reference to the app's view. Required for registration
/// with Fuchsia.
/// ime_service: a handle to Fuchsia's input method service.
/// keyboard: the keyboard listener, gets notified of key presses and
/// releases.
/// dispatch_callback: a function used to send a Flutter platform message.
TextDelegate(fuchsia::ui::views::ViewRef view_ref,
fuchsia::ui::input::ImeServiceHandle ime_service,
fuchsia::ui::input3::KeyboardHandle keyboard,
std::function<void(const FlutterKeyEvent*)> dispatch_callback);
TextDelegate(const TextDelegate&) = delete;
TextDelegate& operator=(const TextDelegate&) = delete;
/// |fuchsia.ui.input3.KeyboardListener|
/// Called by the embedder every time there is a key event to process.
void OnKeyEvent(fuchsia::ui::input3::KeyEvent key_event,
fuchsia::ui::input3::KeyboardListener::OnKeyEventCallback callback) override;
/// |fuchsia::ui::input::InputMethodEditorClient|
/// Called by the embedder every time the edit state is updated.
void DidUpdateState(fuchsia::ui::input::TextInputState state,
std::unique_ptr<fuchsia::ui::input::InputEvent> event) override;
/// |fuchsia::ui::input::InputMethodEditorClient|
/// Called by the embedder when the action key is pressed, and the requested
/// action is supplied to Flutter.
void OnAction(fuchsia::ui::input::InputMethodAction action) override;
/// Gets a new input method editor from the input connection. Run when both
/// Scenic has focus and Flutter has requested input with setClient.
void ActivateIme();
/// Detaches the input method editor connection, ending the edit session and
/// closing the onscreen keyboard. Call when input is no longer desired,
/// either because Scenic says we lost focus or when Flutter no longer has a
/// text field focused.
void DeactivateIme();
/// Returns true if there is a text state (i.e. if some text editing is in
/// progress).
bool HasTextState() { return last_text_state_.has_value(); }
/// Activates the input method editor, assigning |action| to the "enter" key.
/// This action will be reported by |OnAction| above when the "enter" key is
/// pressed. Note that in the case of multi-line text editors, |OnAction| will
/// never be called: instead, the text editor will insert a newline into the
/// edited text.
void ActivateIme(fuchsia::ui::input::InputMethodAction action);
/// Converts Fuchsia platform key codes into Flutter key codes.
Keyboard keyboard_translator_;
/// A callback for sending a single Flutter platform message.
std::function<void(const FlutterKeyEvent* event)> dispatch_callback_;
/// TextDelegate server-side binding. Methods called when the text edit state
/// is updated.
fidl::Binding<fuchsia::ui::input::InputMethodEditorClient> ime_client_;
/// An interface for interacting with a text input control.
fuchsia::ui::input::InputMethodEditorPtr ime_;
/// An interface for requesting the InputMethodEditor.
fuchsia::ui::input::ImeServicePtr text_sync_service_;
/// The locally-unique identifier of the text input currently in use. Flutter
/// usually uses only one at a time.
/// int current_text_input_client_ = 0;
/// TextDelegate server side binding. Methods called when a key is pressed.
fidl::Binding<fuchsia::ui::input3::KeyboardListener> keyboard_listener_binding_;
/// The client-side stub for calling the Keyboard protocol.
fuchsia::ui::input3::KeyboardPtr keyboard_;
/// last_text_state_ is the last state of the text input as reported by the IME
/// or initialized by Flutter. We set it to null if Flutter doesn't want any
/// input, since then there is no text input state at all.
/// If nullptr, then no editing is in progress.
std::optional<fuchsia::ui::input::TextInputState> last_text_state_;
/// The action that Flutter expects to happen when the user presses the "enter"
/// key. For example, it could be `InputMethodAction::DONE` which would cause
/// text editing to stop and the current text to be accepted.
/// If set to std::nullopt, then no editing is in progress.
std::optional<fuchsia::ui::input::InputMethodAction> requested_text_action_;
} // namespace embedder