| // 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 "flutter/shell/platform/linux/fl_key_event_plugin.h" |
| |
| #include <gtk/gtk.h> |
| |
| #include "flutter/shell/platform/linux/fl_text_input_plugin.h" |
| #include "flutter/shell/platform/linux/public/flutter_linux/fl_basic_message_channel.h" |
| #include "flutter/shell/platform/linux/public/flutter_linux/fl_json_message_codec.h" |
| |
| static constexpr char kChannelName[] = "flutter/keyevent"; |
| static constexpr char kTypeKey[] = "type"; |
| static constexpr char kTypeValueUp[] = "keyup"; |
| static constexpr char kTypeValueDown[] = "keydown"; |
| static constexpr char kKeymapKey[] = "keymap"; |
| static constexpr char kKeyCodeKey[] = "keyCode"; |
| static constexpr char kScanCodeKey[] = "scanCode"; |
| static constexpr char kModifiersKey[] = "modifiers"; |
| static constexpr char kToolkitKey[] = "toolkit"; |
| static constexpr char kUnicodeScalarValuesKey[] = "unicodeScalarValues"; |
| |
| static constexpr char kGtkToolkit[] = "gtk"; |
| static constexpr char kLinuxKeymap[] = "linux"; |
| |
| static constexpr uint64_t kMaxPendingEvents = 1000; |
| |
| // Definition of the FlKeyEventPlugin GObject class. |
| |
| struct _FlKeyEventPlugin { |
| GObject parent_instance; |
| |
| FlBasicMessageChannel* channel = nullptr; |
| FlTextInputPlugin* text_input_plugin = nullptr; |
| FlKeyEventPluginCallback response_callback = nullptr; |
| GPtrArray* pending_events; |
| }; |
| |
| G_DEFINE_TYPE(FlKeyEventPlugin, fl_key_event_plugin, G_TYPE_OBJECT) |
| |
| // Declare and define a private pair object to bind the id and the event |
| // together. |
| |
| G_DECLARE_FINAL_TYPE(FlKeyEventPair, |
| fl_key_event_pair, |
| FL, |
| KEY_EVENT_PAIR, |
| GObject); |
| |
| struct _FlKeyEventPair { |
| GObject parent_instance; |
| |
| uint64_t id; |
| GdkEventKey* event; |
| }; |
| |
| G_DEFINE_TYPE(FlKeyEventPair, fl_key_event_pair, G_TYPE_OBJECT) |
| |
| // Dispose method for FlKeyEventPair. |
| static void fl_key_event_pair_dispose(GObject* object) { |
| // Redundant, but added so that we don't get a warning about unused function |
| // for FL_IS_KEY_EVENT_PAIR. |
| g_return_if_fail(FL_IS_KEY_EVENT_PAIR(object)); |
| |
| FlKeyEventPair* self = FL_KEY_EVENT_PAIR(object); |
| g_clear_pointer(&self->event, gdk_event_free); |
| G_OBJECT_CLASS(fl_key_event_pair_parent_class)->dispose(object); |
| } |
| |
| // Class Initialization method for FlKeyEventPair class. |
| static void fl_key_event_pair_class_init(FlKeyEventPairClass* klass) { |
| G_OBJECT_CLASS(klass)->dispose = fl_key_event_pair_dispose; |
| } |
| |
| // Initialization for FlKeyEventPair instances. |
| static void fl_key_event_pair_init(FlKeyEventPair* self) {} |
| |
| // Creates a new FlKeyEventPair instance, given a unique ID, and an event struct |
| // to keep. |
| FlKeyEventPair* fl_key_event_pair_new(uint64_t id, GdkEventKey* event) { |
| FlKeyEventPair* self = |
| FL_KEY_EVENT_PAIR(g_object_new(fl_key_event_pair_get_type(), nullptr)); |
| |
| // Copy the event to preserve refcounts for referenced values (mainly the |
| // window). |
| GdkEventKey* event_copy = reinterpret_cast<GdkEventKey*>( |
| gdk_event_copy(reinterpret_cast<GdkEvent*>(event))); |
| self->id = id; |
| self->event = event_copy; |
| return self; |
| } |
| |
| // Declare and define a private class to hold response data from the framework. |
| G_DECLARE_FINAL_TYPE(FlKeyEventResponseData, |
| fl_key_event_response_data, |
| FL, |
| KEY_EVENT_RESPONSE_DATA, |
| GObject); |
| |
| struct _FlKeyEventResponseData { |
| GObject parent_instance; |
| |
| FlKeyEventPlugin* plugin; |
| uint64_t id; |
| gpointer user_data; |
| }; |
| |
| // Definition for FlKeyEventResponseData private class. |
| G_DEFINE_TYPE(FlKeyEventResponseData, fl_key_event_response_data, G_TYPE_OBJECT) |
| |
| // Dispose method for FlKeyEventResponseData private class. |
| static void fl_key_event_response_data_dispose(GObject* object) { |
| g_return_if_fail(FL_IS_KEY_EVENT_RESPONSE_DATA(object)); |
| FlKeyEventResponseData* self = FL_KEY_EVENT_RESPONSE_DATA(object); |
| // Don't need to weak pointer anymore. |
| g_object_remove_weak_pointer(G_OBJECT(self->plugin), |
| reinterpret_cast<gpointer*>(&(self->plugin))); |
| } |
| |
| // Class initialization method for FlKeyEventResponseData private class. |
| static void fl_key_event_response_data_class_init( |
| FlKeyEventResponseDataClass* klass) { |
| G_OBJECT_CLASS(klass)->dispose = fl_key_event_response_data_dispose; |
| } |
| |
| // Instance initialization method for FlKeyEventResponseData private class. |
| static void fl_key_event_response_data_init(FlKeyEventResponseData* self) {} |
| |
| // Creates a new FlKeyEventResponseData private class with a plugin that created |
| // the request, a unique ID for tracking, and optional user data. |
| // Will keep a weak pointer to the plugin. |
| FlKeyEventResponseData* fl_key_event_response_data_new(FlKeyEventPlugin* plugin, |
| uint64_t id, |
| gpointer user_data) { |
| FlKeyEventResponseData* self = FL_KEY_EVENT_RESPONSE_DATA( |
| g_object_new(fl_key_event_response_data_get_type(), nullptr)); |
| |
| self->plugin = plugin; |
| // Add a weak pointer so we can know if the key event plugin disappeared |
| // while the framework was responding. |
| g_object_add_weak_pointer(G_OBJECT(plugin), |
| reinterpret_cast<gpointer*>(&(self->plugin))); |
| self->id = id; |
| self->user_data = user_data; |
| return self; |
| } |
| |
| // Calculates a unique ID for a given GdkEventKey object to use for |
| // identification of responses from the framework. |
| static uint64_t get_event_id(GdkEventKey* event) { |
| // Combine the event timestamp, the type of event, and the hardware keycode |
| // (scan code) of the event to come up with a unique id for this event that |
| // can be derived solely from the event data itself, so that we can identify |
| // whether or not we have seen this event already. |
| return (event->time & 0xffffffff) | |
| (static_cast<uint64_t>(event->type) & 0xffff) << 32 | |
| (static_cast<uint64_t>(event->hardware_keycode) & 0xffff) << 48; |
| } |
| |
| // Finds an event in the event queue that was sent to the framework by its ID. |
| static GdkEventKey* find_pending_event(FlKeyEventPlugin* self, uint64_t id) { |
| if (self->pending_events->len == 0 || |
| FL_KEY_EVENT_PAIR(g_ptr_array_index(self->pending_events, 0))->id != id) { |
| return nullptr; |
| } |
| |
| return FL_KEY_EVENT_PAIR(g_ptr_array_index(self->pending_events, 0))->event; |
| } |
| |
| // Removes an event from the pending event queue. |
| static void remove_pending_event(FlKeyEventPlugin* self, uint64_t id) { |
| if (self->pending_events->len == 0 || |
| FL_KEY_EVENT_PAIR(g_ptr_array_index(self->pending_events, 0))->id != id) { |
| g_warning( |
| "Tried to remove pending event with id %ld, but the event was out of " |
| "order, or is unknown.", |
| id); |
| return; |
| } |
| g_ptr_array_remove_index(self->pending_events, 0); |
| } |
| |
| // Adds an GdkEventKey to the pending event queue, with a unique ID, and the |
| // plugin that added it. |
| static void add_pending_event(FlKeyEventPlugin* self, |
| uint64_t id, |
| GdkEventKey* event) { |
| if (self->pending_events->len > kMaxPendingEvents) { |
| g_warning( |
| "There are %d keyboard events that have not yet received a " |
| "response from the framework. Are responses being sent?", |
| self->pending_events->len); |
| } |
| g_ptr_array_add(self->pending_events, fl_key_event_pair_new(id, event)); |
| } |
| |
| // Handles a response from the framework to a key event sent to the framework |
| // earlier. |
| static void handle_response(GObject* object, |
| GAsyncResult* result, |
| gpointer user_data) { |
| g_autoptr(FlKeyEventResponseData) data = |
| FL_KEY_EVENT_RESPONSE_DATA(user_data); |
| |
| // Will also return if the weak pointer has been destroyed. |
| if (data->plugin == nullptr) { |
| return; |
| } |
| |
| FlKeyEventPlugin* self = data->plugin; |
| |
| g_autoptr(GError) error = nullptr; |
| FlBasicMessageChannel* messageChannel = FL_BASIC_MESSAGE_CHANNEL(object); |
| FlValue* message = |
| fl_basic_message_channel_send_finish(messageChannel, result, &error); |
| if (error != nullptr) { |
| g_warning("Unable to retrieve framework response: %s", error->message); |
| return; |
| } |
| g_autoptr(FlValue) handled_value = fl_value_lookup_string(message, "handled"); |
| bool handled = FALSE; |
| if (handled_value != nullptr) { |
| GdkEventKey* event = find_pending_event(self, data->id); |
| if (event == nullptr) { |
| g_warning( |
| "Event response for event id %ld received, but event was received " |
| "out of order, or is unknown.", |
| data->id); |
| } else { |
| handled = fl_value_get_bool(handled_value); |
| if (!handled) { |
| if (self->text_input_plugin != nullptr) { |
| // Propagate the event to the text input plugin. |
| handled = fl_text_input_plugin_filter_keypress( |
| self->text_input_plugin, event); |
| } |
| // Dispatch the event to other GTK windows if the text input plugin |
| // didn't handle it. We keep track of the event id so we can recognize |
| // the event when our window receives it again and not respond to it. If |
| // the response callback is set, then use that instead. |
| if (!handled && self->response_callback == nullptr) { |
| gdk_event_put(reinterpret_cast<GdkEvent*>(event)); |
| } |
| } |
| } |
| } |
| |
| if (handled) { |
| // Because the event was handled, we no longer need to track it. Unhandled |
| // events will be removed when the event is re-dispatched to the window. |
| remove_pending_event(self, data->id); |
| } |
| |
| if (self->response_callback != nullptr) { |
| self->response_callback(object, message, handled, data->user_data); |
| } |
| } |
| |
| // Disposes of an FlKeyEventPlugin instance. |
| static void fl_key_event_plugin_dispose(GObject* object) { |
| FlKeyEventPlugin* self = FL_KEY_EVENT_PLUGIN(object); |
| |
| g_clear_object(&self->channel); |
| g_object_remove_weak_pointer( |
| G_OBJECT(self->text_input_plugin), |
| reinterpret_cast<gpointer*>(&(self->text_input_plugin))); |
| g_ptr_array_free(self->pending_events, TRUE); |
| |
| G_OBJECT_CLASS(fl_key_event_plugin_parent_class)->dispose(object); |
| } |
| |
| // Initializes the FlKeyEventPlugin class methods. |
| static void fl_key_event_plugin_class_init(FlKeyEventPluginClass* klass) { |
| G_OBJECT_CLASS(klass)->dispose = fl_key_event_plugin_dispose; |
| } |
| |
| // Initializes an FlKeyEventPlugin instance. |
| static void fl_key_event_plugin_init(FlKeyEventPlugin* self) {} |
| |
| // Creates a new FlKeyEventPlugin instance, with a messenger used to send |
| // messages to the framework, an FlTextInputPlugin used to handle key events |
| // that the framework doesn't handle. Mainly for testing purposes, it also takes |
| // an optional callback to call when a response is received, and an optional |
| // channel name to use when sending messages. |
| FlKeyEventPlugin* fl_key_event_plugin_new( |
| FlBinaryMessenger* messenger, |
| FlTextInputPlugin* text_input_plugin, |
| FlKeyEventPluginCallback response_callback, |
| const char* channel_name) { |
| g_return_val_if_fail(FL_IS_BINARY_MESSENGER(messenger), nullptr); |
| g_return_val_if_fail(FL_IS_TEXT_INPUT_PLUGIN(text_input_plugin), nullptr); |
| |
| FlKeyEventPlugin* self = FL_KEY_EVENT_PLUGIN( |
| g_object_new(fl_key_event_plugin_get_type(), nullptr)); |
| |
| g_autoptr(FlJsonMessageCodec) codec = fl_json_message_codec_new(); |
| self->channel = fl_basic_message_channel_new( |
| messenger, channel_name == nullptr ? kChannelName : channel_name, |
| FL_MESSAGE_CODEC(codec)); |
| self->response_callback = response_callback; |
| // Add a weak pointer so we know if the text input plugin goes away. |
| g_object_add_weak_pointer( |
| G_OBJECT(text_input_plugin), |
| reinterpret_cast<gpointer*>(&(self->text_input_plugin))); |
| self->text_input_plugin = text_input_plugin; |
| |
| self->pending_events = g_ptr_array_new_with_free_func(g_object_unref); |
| return self; |
| } |
| |
| // Sends a key event to the framework. |
| bool fl_key_event_plugin_send_key_event(FlKeyEventPlugin* self, |
| GdkEventKey* event, |
| gpointer user_data) { |
| g_return_val_if_fail(FL_IS_KEY_EVENT_PLUGIN(self), FALSE); |
| g_return_val_if_fail(event != nullptr, FALSE); |
| |
| // Get an ID for the event, so we can match them up when we get a response |
| // from the framework. Use the event time, type, and hardware keycode as a |
| // unique ID, since they are part of the event structure that we can look up |
| // when we receive a random event that may or may not have been |
| // tracked/produced by this code. |
| uint64_t id = get_event_id(event); |
| if (self->pending_events->len != 0 && |
| FL_KEY_EVENT_PAIR(g_ptr_array_index(self->pending_events, 0))->id == id) { |
| // If the event is at the head of the queue of pending events we've seen, |
| // and has the same id, then we know that this is a re-dispatched event, and |
| // we shouldn't respond to it, but we should remove it from tracking. |
| remove_pending_event(self, id); |
| return FALSE; |
| } |
| |
| const gchar* type; |
| switch (event->type) { |
| case GDK_KEY_PRESS: |
| type = kTypeValueDown; |
| break; |
| case GDK_KEY_RELEASE: |
| type = kTypeValueUp; |
| break; |
| default: |
| return FALSE; |
| } |
| |
| int64_t scan_code = event->hardware_keycode; |
| int64_t unicodeScalarValues = gdk_keyval_to_unicode(event->keyval); |
| |
| // For most modifier keys, GTK keeps track of the "pressed" state of the |
| // modifier keys. Flutter uses this information to keep modifier keys from |
| // being "stuck" when a key-up event is lost because it happens after the app |
| // loses focus. |
| // |
| // For Lock keys (ShiftLock, CapsLock, NumLock), however, GTK keeps track of |
| // the state of the locks themselves, not the "pressed" state of the key. |
| // |
| // Since Flutter expects the "pressed" state of the modifier keys, the lock |
| // state for these keys is discarded here, and it is substituted for the |
| // pressed state of the key. |
| // |
| // This code has the flaw that if a key event is missed due to the app losing |
| // focus, then this state will still think the key is pressed when it isn't, |
| // but that is no worse than for "regular" keys until we implement the |
| // sync/cancel events on app focus changes. |
| // |
| // This is necessary to do here instead of in the framework because Flutter |
| // does modifier key syncing in the framework, and will turn on/off these keys |
| // as being "pressed" whenever the lock is on, which breaks a lot of |
| // interactions (for example, if shift-lock is on, tab traversal is broken). |
| // |
| // TODO(gspencergoog): get rid of this tracked state when we are tracking the |
| // state of all keys and sending sync/cancel events when focus is gained/lost. |
| |
| // Remove lock states from state mask. |
| guint state = event->state & ~(GDK_LOCK_MASK | GDK_MOD2_MASK); |
| |
| static bool shift_lock_pressed = FALSE; |
| static bool caps_lock_pressed = FALSE; |
| static bool num_lock_pressed = FALSE; |
| switch (event->keyval) { |
| case GDK_KEY_Num_Lock: |
| num_lock_pressed = event->type == GDK_KEY_PRESS; |
| break; |
| case GDK_KEY_Caps_Lock: |
| caps_lock_pressed = event->type == GDK_KEY_PRESS; |
| break; |
| case GDK_KEY_Shift_Lock: |
| shift_lock_pressed = event->type == GDK_KEY_PRESS; |
| break; |
| } |
| |
| // Add back in the state matching the actual pressed state of the lock keys, |
| // not the lock states. |
| state |= (shift_lock_pressed || caps_lock_pressed) ? GDK_LOCK_MASK : 0x0; |
| state |= num_lock_pressed ? GDK_MOD2_MASK : 0x0; |
| |
| g_autoptr(FlValue) message = fl_value_new_map(); |
| fl_value_set_string_take(message, kTypeKey, fl_value_new_string(type)); |
| fl_value_set_string_take(message, kKeymapKey, |
| fl_value_new_string(kLinuxKeymap)); |
| fl_value_set_string_take(message, kScanCodeKey, fl_value_new_int(scan_code)); |
| fl_value_set_string_take(message, kToolkitKey, |
| fl_value_new_string(kGtkToolkit)); |
| fl_value_set_string_take(message, kKeyCodeKey, |
| fl_value_new_int(event->keyval)); |
| fl_value_set_string_take(message, kModifiersKey, fl_value_new_int(state)); |
| if (unicodeScalarValues != 0) { |
| fl_value_set_string_take(message, kUnicodeScalarValuesKey, |
| fl_value_new_int(unicodeScalarValues)); |
| } |
| |
| // Track the event as pending a response from the framework. |
| add_pending_event(self, id, event); |
| FlKeyEventResponseData* data = |
| fl_key_event_response_data_new(self, id, user_data); |
| // Send the message off to the framework for handling (or not). |
| fl_basic_message_channel_send(self->channel, message, nullptr, |
| handle_response, data); |
| // Return true before we know what the framework will do, because if it |
| // doesn't handle the key, we'll re-dispatch it later. |
| return TRUE; |
| } |