fl_method_channel.h File Reference

#include <gio/gio.h>
#include <glib-object.h>
#include <gmodule.h>
#include "fl_binary_messenger.h"
#include "fl_method_call.h"
#include "fl_method_codec.h"
#include "fl_method_response.h"

Go to the source code of this file.

Functions
G_BEGIN_DECLS G_MODULE_EXPORT	G_DECLARE_FINAL_TYPE (FlMethodChannel, fl_method_channel, FL, METHOD_CHANNEL, GObject) typedef void(*FlMethodChannelMethodCallHandler)(FlMethodChannel *channel
: a channel name.
fl_method_channel_new: @messenger: an #FlBinaryMessenger. @codec: the method codec. Creates a new method channel. @codec must match the codec used on the Dart end of the channel. Returns: a new #FlMethodChannel.
FlMethodChannel *	fl_method_channel_new (FlBinaryMessenger *messenger, const gchar *name, FlMethodCodec *codec)
void	fl_method_channel_set_method_call_handler (FlMethodChannel *channel, FlMethodChannelMethodCallHandler handler, gpointer user_data, GDestroyNotify destroy_notify)
void	fl_method_channel_invoke_method (FlMethodChannel *channel, const gchar *method, FlValue *args, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data)
FlMethodResponse *	fl_method_channel_invoke_method_finish (FlMethodChannel *channel, GAsyncResult *result, GError **error)

Variables
G_BEGIN_DECLS G_MODULE_EXPORT FlMethodCall *	method_call
G_BEGIN_DECLS G_MODULE_EXPORT FlMethodCall gpointer	user_data

Function Documentation

fl_method_channel_invoke_method()

void fl_method_channel_invoke_method	(	FlMethodChannel *	channel,
		const gchar *	method,
		FlValue *	args,
		GCancellable *	cancellable,
		GAsyncReadyCallback	callback,
		gpointer	user_data
	)

fl_method_channel_invoke_method: @channel: an #FlMethodChannel. @method: the method to call. @args: (allow-none): arguments to the method, must match what the #FlMethodCodec supports. @cancellable: (allow-none): a #GCancellable or NULL. @callback: (scope async): (allow-none): a #GAsyncReadyCallback to call when the request is satisfied or NULL to ignore the response. @user_data: (closure): user data to pass to @callback.

Calls a method on this channel.

Definition at line 162 of file fl_method_channel.cc.

                        {
  g_return_if_fail(FL_IS_METHOD_CHANNEL(self));
  g_return_if_fail(method != nullptr);
 
  g_autoptr(GTask) task =
      callback != nullptr ? g_task_new(self, cancellable, callback, user_data)
                          : nullptr;
 
  g_autoptr(GError) error = nullptr;
  g_autoptr(GBytes) message =
      fl_method_codec_encode_method_call(self->codec, method, args, &error);
  if (message == nullptr) {
    if (task != nullptr) {
      g_task_return_error(task, error);
    }
    return;
  }
 
  fl_binary_messenger_send_on_channel(
      self->messenger, self->name, message, cancellable,
      callback != nullptr ? message_response_cb : nullptr,
      g_steal_pointer(&task));
}

fl_method_channel_invoke_method_finish()

FlMethodResponse * fl_method_channel_invoke_method_finish	(	FlMethodChannel *	channel,
		GAsyncResult *	result,
		GError **	error
	)

fl_method_channel_invoke_method_finish: @channel: an #FlMethodChannel.

Returns

: #GAsyncResult. @error: (allow-none): #GError location to store the error occurring, or NULL to ignore.

Completes request started with fl_method_channel_invoke_method().

Returns: (transfer full): an #FlMethodResponse or NULL on error.

Definition at line 192 of file fl_method_channel.cc.

                    {
  g_return_val_if_fail(FL_IS_METHOD_CHANNEL(self), nullptr);
  g_return_val_if_fail(g_task_is_valid(result, self), nullptr);
 
  g_autoptr(GTask) task = G_TASK(result);
  GAsyncResult* r = G_ASYNC_RESULT(g_task_propagate_pointer(task, nullptr));
 
  g_autoptr(GBytes) response =
      fl_binary_messenger_send_on_channel_finish(self->messenger, r, error);
  if (response == nullptr) {
    return nullptr;
  }
 
  return fl_method_codec_decode_response(self->codec, response, error);
}

fl_method_channel_new()

FlMethodChannel * fl_method_channel_new	(	FlBinaryMessenger *	messenger,
		const gchar *	name,
		FlMethodCodec *	codec
	)

Definition at line 112 of file fl_method_channel.cc.

                          {
  g_return_val_if_fail(FL_IS_BINARY_MESSENGER(messenger), nullptr);
  g_return_val_if_fail(name != nullptr, nullptr);
  g_return_val_if_fail(FL_IS_METHOD_CODEC(codec), nullptr);
 
  FlMethodChannel* self =
      FL_METHOD_CHANNEL(g_object_new(fl_method_channel_get_type(), nullptr));
 
  self->messenger = FL_BINARY_MESSENGER(g_object_ref(messenger));
  self->name = g_strdup(name);
  self->codec = FL_METHOD_CODEC(g_object_ref(codec));
 
  fl_binary_messenger_set_message_handler_on_channel(
      self->messenger, self->name, message_cb, g_object_ref(self),
      channel_closed_cb);
 
  return self;
}

fl_method_channel_set_method_call_handler()

void fl_method_channel_set_method_call_handler	(	FlMethodChannel *	channel,
		FlMethodChannelMethodCallHandler	handler,
		gpointer	user_data,
		GDestroyNotify	destroy_notify
	)

fl_method_channel_set_method_call_handler: @channel: an #FlMethodChannel. @handler: function to call when a method call is received on this channel. @user_data: (closure): user data to pass to @handler. @destroy_notify: (allow-none): a function which gets called to free @user_data, or NULL.

Sets the function called when a method call is received from the Dart side of the channel. See #FlMethodChannelMethodCallHandler for details on how to respond to method calls.

The handler is removed if the channel is closed or is replaced by another handler, set @destroy_notify if you want to detect this.

Definition at line 134 of file fl_method_channel.cc.

                                   {
  g_return_if_fail(FL_IS_METHOD_CHANNEL(self));
 
  // Don't set handler if channel closed.
  if (self->channel_closed) {
    if (handler != nullptr) {
      g_warning(
          "Attempted to set method call handler on a closed FlMethodChannel");
    }
    if (destroy_notify != nullptr) {
      destroy_notify(user_data);
    }
    return;
  }
 
  if (self->method_call_handler_destroy_notify != nullptr) {
    self->method_call_handler_destroy_notify(self->method_call_handler_data);
  }
 
  self->method_call_handler = handler;
  self->method_call_handler_data = user_data;
  self->method_call_handler_destroy_notify = destroy_notify;
}

G_DECLARE_FINAL_TYPE()

G_BEGIN_DECLS G_MODULE_EXPORT G_DECLARE_FINAL_TYPE	(	FlMethodChannel	,
		fl_method_channel	,
		FL	,
		METHOD_CHANNEL	,
		GObject
	)

FlMethodChannel:

#FlMethodChannel is an object that allows method calls to and from Dart code.

The following example shows how to call and handle methods on a channel. See #FlMethodResponse for how to handle errors in more detail.

|[ static FlMethodChannel *channel = NULL;

static void method_call_cb (FlMethodChannel* channel, FlMethodCall* method_call, gpointer user_data) { g_autoptr(FlMethodResponse) response = NULL; if (strcmp (fl_method_call_get_name (method_call), "Foo.bar") == 0) { g_autoptr(GError) bar_error = NULL; g_autoptr(FlValue) result = do_bar (fl_method_call_get_args (method_call), &bar_error); if (result == NULL) { response = FL_METHOD_RESPONSE (fl_method_error_response_new ("bar error", bar_error->message, nullptr); } else { response = FL_METHOD_RESPONSE (fl_method_success_response_new (result)); } } else { response = FL_METHOD_RESPONSE (fl_method_not_implemented_response_new ()); }

g_autoptr(GError) error = NULL; if (!fl_method_call_respond(method_call, response, &error)) g_warning ("Failed to send response: %s", error->message); }

static void method_response_cb(GObject *object, GAsyncResult *result, gpointer user_data) { g_autoptr(GError) error = NULL; g_autoptr(FlMethodResponse) response = fl_method_channel_invoke_method_finish (FL_METHOD_CODEC (object), result, &error); if (response == NULL) { g_warning ("Failed to call method: %s", error->message); return; }

g_autoptr(FlValue) value = fl_method_response_get_result (response, &error); if (response == NULL) { g_warning ("Method returned error: %s", error->message); return; }

use_result (value); }

static void call_method () { g_autoptr(FlStandardMethodCodec) codec = fl_standard_method_codec_new (); channel = fl_method_channel_new(messenger, "flutter/foo", FL_METHOD_CODEC (codec)); fl_method_channel_set_method_call_handler (channel, method_call_cb, NULL, NULL);

g_autoptr(FlValue) args = fl_value_new_string ("Hello World"); fl_method_channel_invoke_method (channel, "Foo.foo", args, cancellable, method_response_cb, NULL); } ]|

#FlMethodChannel matches the MethodChannel class in the Flutter services library. FlMethodChannelMethodCallHandler: @channel: an #FlMethodChannel. @method_call: an #FlMethodCall. @user_data: (closure): data provided when registering this handler.

Function called when a method call is received. Respond to the method call with fl_method_call_respond(). If the response is not occurring in this callback take a reference to @method_call and release that once it has been responded to. Failing to respond before the last reference to @method_call is dropped is a programming error.

Variable Documentation

method_call

G_BEGIN_DECLS G_MODULE_EXPORT FlMethodCall* method_call

Definition at line 120 of file fl_method_channel.h.

user_data

G_BEGIN_DECLS G_MODULE_EXPORT FlMethodCall gpointer user_data

Definition at line 121 of file fl_method_channel.h.