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| 1 | +// Copyright 2013 The Flutter Authors. All rights reserved. |
| 2 | +// Use of this source code is governed by a BSD-style license that can be |
| 3 | +// found in the LICENSE file. |
| 4 | + |
| 5 | +#include "flutter/shell/platform/linux/public/flutter_linux/fl_event_channel.h" |
| 6 | + |
| 7 | +#include <gmodule.h> |
| 8 | + |
| 9 | +#include "flutter/shell/platform/linux/fl_method_codec_private.h" |
| 10 | + |
| 11 | +static constexpr char kListenMethod[] = "listen"; |
| 12 | +static constexpr char kCancelMethod[] = "cancel"; |
| 13 | +static constexpr char kEventRequestError[] = "error"; |
| 14 | + |
| 15 | +struct _FlEventChannel { |
| 16 | + GObject parent_instance; |
| 17 | + |
| 18 | + // Messenger to communicate on. |
| 19 | + FlBinaryMessenger* messenger; |
| 20 | + |
| 21 | + // Channel name. |
| 22 | + gchar* name; |
| 23 | + |
| 24 | + // Codec to en/decode messages. |
| 25 | + FlMethodCodec* codec; |
| 26 | + |
| 27 | + // Function called when the stream is listened to / cancelled. |
| 28 | + FlEventChannelHandler listen_handler; |
| 29 | + FlEventChannelHandler cancel_handler; |
| 30 | + gpointer handler_data; |
| 31 | + GDestroyNotify handler_data_destroy_notify; |
| 32 | +}; |
| 33 | + |
| 34 | +struct _FlEventChannelResponseHandle { |
| 35 | + GObject parent_instance; |
| 36 | + |
| 37 | + FlBinaryMessengerResponseHandle* response_handle; |
| 38 | +}; |
| 39 | + |
| 40 | +// Added here to stop the compiler from optimising this function away. |
| 41 | +G_MODULE_EXPORT GType fl_event_channel_get_type(); |
| 42 | + |
| 43 | +G_DEFINE_TYPE(FlEventChannel, fl_event_channel, G_TYPE_OBJECT) |
| 44 | + |
| 45 | +// Handle method calls from the Dart side of the channel. |
| 46 | +static FlMethodErrorResponse* handle_method_call(FlEventChannel* self, |
| 47 | + const gchar* name, |
| 48 | + FlValue* args) { |
| 49 | + FlEventChannelHandler handler; |
| 50 | + if (g_strcmp0(name, kListenMethod) == 0) { |
| 51 | + handler = self->listen_handler; |
| 52 | + } else if (g_strcmp0(name, kCancelMethod) == 0) { |
| 53 | + handler = self->cancel_handler; |
| 54 | + } else { |
| 55 | + g_autofree gchar* message = |
| 56 | + g_strdup_printf("Unknown event channel request '%s'", name); |
| 57 | + return fl_method_error_response_new(kEventRequestError, message, nullptr); |
| 58 | + } |
| 59 | + |
| 60 | + // If not handled, just accept requests. |
| 61 | + if (handler == nullptr) { |
| 62 | + return nullptr; |
| 63 | + } |
| 64 | + |
| 65 | + return handler(self, args, self->handler_data); |
| 66 | +} |
| 67 | + |
| 68 | +// Called when a binary message is received on this channel. |
| 69 | +static void message_cb(FlBinaryMessenger* messenger, |
| 70 | + const gchar* channel, |
| 71 | + GBytes* message, |
| 72 | + FlBinaryMessengerResponseHandle* response_handle, |
| 73 | + gpointer user_data) { |
| 74 | + FlEventChannel* self = FL_EVENT_CHANNEL(user_data); |
| 75 | + |
| 76 | + g_autofree gchar* name = nullptr; |
| 77 | + g_autoptr(GError) error = nullptr; |
| 78 | + g_autoptr(FlValue) args = nullptr; |
| 79 | + if (!fl_method_codec_decode_method_call(self->codec, message, &name, &args, |
| 80 | + &error)) { |
| 81 | + g_warning("Failed to decode message on event channel %s: %s", self->name, |
| 82 | + error->message); |
| 83 | + fl_binary_messenger_send_response(messenger, response_handle, nullptr, |
| 84 | + nullptr); |
| 85 | + return; |
| 86 | + } |
| 87 | + |
| 88 | + g_autoptr(FlMethodErrorResponse) response = |
| 89 | + handle_method_call(self, name, args); |
| 90 | + |
| 91 | + g_autoptr(GBytes) data = nullptr; |
| 92 | + if (response == nullptr) { |
| 93 | + g_autoptr(GError) codec_error = nullptr; |
| 94 | + data = fl_method_codec_encode_success_envelope(self->codec, nullptr, |
| 95 | + &codec_error); |
| 96 | + if (data == nullptr) { |
| 97 | + g_warning("Failed to encode event channel %s success response: %s", |
| 98 | + self->name, codec_error->message); |
| 99 | + } |
| 100 | + } else { |
| 101 | + g_autoptr(GError) codec_error = nullptr; |
| 102 | + data = fl_method_codec_encode_error_envelope( |
| 103 | + self->codec, fl_method_error_response_get_code(response), |
| 104 | + fl_method_error_response_get_message(response), |
| 105 | + fl_method_error_response_get_details(response), &codec_error); |
| 106 | + if (data == nullptr) { |
| 107 | + g_warning("Failed to encode event channel %s error response: %s", |
| 108 | + self->name, codec_error->message); |
| 109 | + } |
| 110 | + } |
| 111 | + |
| 112 | + if (!fl_binary_messenger_send_response(messenger, response_handle, data, |
| 113 | + &error)) { |
| 114 | + g_warning("Failed to send event channel response: %s", error->message); |
| 115 | + } |
| 116 | +} |
| 117 | + |
| 118 | +// Removes handlers and their associated data. |
| 119 | +static void remove_handlers(FlEventChannel* self) { |
| 120 | + if (self->handler_data_destroy_notify != nullptr) { |
| 121 | + self->handler_data_destroy_notify(self->handler_data); |
| 122 | + } |
| 123 | + self->listen_handler = nullptr; |
| 124 | + self->cancel_handler = nullptr; |
| 125 | + self->handler_data = nullptr; |
| 126 | + self->handler_data_destroy_notify = nullptr; |
| 127 | +} |
| 128 | + |
| 129 | +// Called when the channel handler is closed. |
| 130 | +static void channel_closed_cb(gpointer user_data) { |
| 131 | + g_autoptr(FlEventChannel) self = FL_EVENT_CHANNEL(user_data); |
| 132 | + remove_handlers(self); |
| 133 | +} |
| 134 | + |
| 135 | +static void fl_event_channel_dispose(GObject* object) { |
| 136 | + FlEventChannel* self = FL_EVENT_CHANNEL(object); |
| 137 | + |
| 138 | + if (self->messenger != nullptr) { |
| 139 | + fl_binary_messenger_set_message_handler_on_channel( |
| 140 | + self->messenger, self->name, nullptr, nullptr, nullptr); |
| 141 | + } |
| 142 | + |
| 143 | + g_clear_object(&self->messenger); |
| 144 | + g_clear_pointer(&self->name, g_free); |
| 145 | + g_clear_object(&self->codec); |
| 146 | + |
| 147 | + remove_handlers(self); |
| 148 | + |
| 149 | + G_OBJECT_CLASS(fl_event_channel_parent_class)->dispose(object); |
| 150 | +} |
| 151 | + |
| 152 | +static void fl_event_channel_class_init(FlEventChannelClass* klass) { |
| 153 | + G_OBJECT_CLASS(klass)->dispose = fl_event_channel_dispose; |
| 154 | +} |
| 155 | + |
| 156 | +static void fl_event_channel_init(FlEventChannel* self) {} |
| 157 | + |
| 158 | +G_MODULE_EXPORT FlEventChannel* fl_event_channel_new( |
| 159 | + FlBinaryMessenger* messenger, |
| 160 | + const gchar* name, |
| 161 | + FlMethodCodec* codec) { |
| 162 | + g_return_val_if_fail(FL_IS_BINARY_MESSENGER(messenger), nullptr); |
| 163 | + g_return_val_if_fail(name != nullptr, nullptr); |
| 164 | + g_return_val_if_fail(FL_IS_METHOD_CODEC(codec), nullptr); |
| 165 | + |
| 166 | + FlEventChannel* self = |
| 167 | + FL_EVENT_CHANNEL(g_object_new(fl_event_channel_get_type(), nullptr)); |
| 168 | + |
| 169 | + self->messenger = FL_BINARY_MESSENGER(g_object_ref(messenger)); |
| 170 | + self->name = g_strdup(name); |
| 171 | + self->codec = FL_METHOD_CODEC(g_object_ref(codec)); |
| 172 | + |
| 173 | + fl_binary_messenger_set_message_handler_on_channel( |
| 174 | + self->messenger, self->name, message_cb, g_object_ref(self), |
| 175 | + channel_closed_cb); |
| 176 | + |
| 177 | + return self; |
| 178 | +} |
| 179 | + |
| 180 | +G_MODULE_EXPORT void fl_event_channel_set_stream_handlers( |
| 181 | + FlEventChannel* self, |
| 182 | + FlEventChannelHandler listen_handler, |
| 183 | + FlEventChannelHandler cancel_handler, |
| 184 | + gpointer user_data, |
| 185 | + GDestroyNotify destroy_notify) { |
| 186 | + g_return_if_fail(FL_IS_EVENT_CHANNEL(self)); |
| 187 | + |
| 188 | + remove_handlers(self); |
| 189 | + self->listen_handler = listen_handler; |
| 190 | + self->cancel_handler = cancel_handler; |
| 191 | + self->handler_data = user_data; |
| 192 | + self->handler_data_destroy_notify = destroy_notify; |
| 193 | +} |
| 194 | + |
| 195 | +G_MODULE_EXPORT gboolean fl_event_channel_send(FlEventChannel* self, |
| 196 | + FlValue* event, |
| 197 | + GCancellable* cancellable, |
| 198 | + GError** error) { |
| 199 | + g_return_val_if_fail(FL_IS_EVENT_CHANNEL(self), FALSE); |
| 200 | + g_return_val_if_fail(event != nullptr, FALSE); |
| 201 | + |
| 202 | + g_autoptr(GBytes) data = |
| 203 | + fl_method_codec_encode_success_envelope(self->codec, event, error); |
| 204 | + if (data == nullptr) { |
| 205 | + return FALSE; |
| 206 | + } |
| 207 | + |
| 208 | + fl_binary_messenger_send_on_channel(self->messenger, self->name, data, |
| 209 | + cancellable, nullptr, nullptr); |
| 210 | + |
| 211 | + return TRUE; |
| 212 | +} |
| 213 | + |
| 214 | +G_MODULE_EXPORT gboolean fl_event_channel_send_error(FlEventChannel* self, |
| 215 | + const gchar* code, |
| 216 | + const gchar* message, |
| 217 | + FlValue* details, |
| 218 | + GCancellable* cancellable, |
| 219 | + GError** error) { |
| 220 | + g_return_val_if_fail(FL_IS_EVENT_CHANNEL(self), FALSE); |
| 221 | + g_return_val_if_fail(code != nullptr, FALSE); |
| 222 | + g_return_val_if_fail(message != nullptr, FALSE); |
| 223 | + |
| 224 | + g_autoptr(GBytes) data = fl_method_codec_encode_error_envelope( |
| 225 | + self->codec, code, message, details, error); |
| 226 | + if (data == nullptr) { |
| 227 | + return FALSE; |
| 228 | + } |
| 229 | + |
| 230 | + fl_binary_messenger_send_on_channel(self->messenger, self->name, data, |
| 231 | + cancellable, nullptr, nullptr); |
| 232 | + |
| 233 | + return TRUE; |
| 234 | +} |
| 235 | + |
| 236 | +G_MODULE_EXPORT gboolean |
| 237 | +fl_event_channel_send_end_of_stream(FlEventChannel* self, |
| 238 | + GCancellable* cancellable, |
| 239 | + GError** error) { |
| 240 | + g_return_val_if_fail(FL_IS_EVENT_CHANNEL(self), FALSE); |
| 241 | + fl_binary_messenger_send_on_channel(self->messenger, self->name, nullptr, |
| 242 | + cancellable, nullptr, nullptr); |
| 243 | + return TRUE; |
| 244 | +} |
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