Implement Linux part of examples (#108068) Add Linux files for hello_world and platform_channel examples
diff --git a/examples/platform_channel/linux/my_application.cc b/examples/platform_channel/linux/my_application.cc new file mode 100644 index 0000000..da99a0b --- /dev/null +++ b/examples/platform_channel/linux/my_application.cc
@@ -0,0 +1,297 @@ +// Copyright 2014 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 "my_application.h" + +#include <flutter_linux/flutter_linux.h> +#include <math.h> +#include <upower.h> +#ifdef GDK_WINDOWING_X11 +#include <gdk/gdkx.h> +#endif + +#include "flutter/generated_plugin_registrant.h" + +struct _MyApplication { + GtkApplication parent_instance; + char** dart_entrypoint_arguments; + + FlView* view; + + // Connection to UPower. + UpClient* up_client; + GPtrArray* battery_devices; + + // Channel for Dart code to request the battery information. + FlMethodChannel* battery_channel; + + // Channel to send updates to Dart code about battery charging state. + FlEventChannel* charging_channel; + gchar* last_charge_event; + bool emit_charge_events; +}; + +G_DEFINE_TYPE(MyApplication, my_application, GTK_TYPE_APPLICATION) + +// Checks the charging state and emits an event if necessary. +static void update_charging_state(MyApplication* self) { + if (!self->emit_charge_events) { + return; + } + + const gchar* charge_event = "discharging"; + for (guint i = 0; i < self->battery_devices->len; i++) { + UpDevice* device = + static_cast<UpDevice*>(g_ptr_array_index(self->battery_devices, i)); + + guint state; + g_object_get(device, "state", &state, nullptr); + if (state == UP_DEVICE_STATE_CHARGING || + state == UP_DEVICE_STATE_FULLY_CHARGED) { + charge_event = "charging"; + } + } + + if (g_strcmp0(charge_event, self->last_charge_event) != 0) { + g_autoptr(GError) error = nullptr; + g_autoptr(FlValue) value = fl_value_new_string(charge_event); + if (!fl_event_channel_send(self->charging_channel, value, nullptr, + &error)) { + g_warning("Failed to send charging event: %s", error->message); + return; + } + g_free(self->last_charge_event); + self->last_charge_event = g_strdup(charge_event); + } +} + +// Called when a UPower device changes state. +static void up_device_state_changed_cb(MyApplication* self, GParamSpec* pspec, + UpDevice* device) { + update_charging_state(self); +} + +// Called when UPower devices are added. +static void up_device_added_cb(MyApplication* self, UpDevice* device) { + // Listen for state changes from battery_devices. + guint kind; + g_object_get(device, "kind", &kind, nullptr); + if (kind == UP_DEVICE_KIND_BATTERY) { + g_ptr_array_add(self->battery_devices, g_object_ref(device)); + g_signal_connect_swapped(device, "notify::state", + G_CALLBACK(up_device_state_changed_cb), self); + up_device_state_changed_cb(self, nullptr, device); + } +} + +// Called when UPower devices are removed. +static void up_device_removed_cb(MyApplication* self, UpDevice* device) { + g_ptr_array_remove(self->battery_devices, device); + g_signal_handlers_disconnect_matched( + device, G_SIGNAL_MATCH_FUNC, 0, 0, nullptr, + reinterpret_cast<GClosure*>(up_device_state_changed_cb), nullptr); +} + +// Gets the current battery level. +static FlMethodResponse* get_battery_level(MyApplication* self) { + // Find the first available battery and use that. + for (guint i = 0; i < self->battery_devices->len; i++) { + UpDevice* device = + static_cast<UpDevice*>(g_ptr_array_index(self->battery_devices, i)); + + double percentage; + g_object_get(device, "percentage", &percentage, nullptr); + g_autoptr(FlValue) result = + fl_value_new_int(static_cast<int64_t>(round(percentage))); + return FL_METHOD_RESPONSE(fl_method_success_response_new(result)); + } + + return FL_METHOD_RESPONSE(fl_method_error_response_new( + "NO_BATTERY", "Device does not have a battery.", nullptr)); +} + +// Called when the Dart code requests battery information. +static void battery_method_call_cb(FlMethodChannel* channel, + FlMethodCall* method_call, + gpointer user_data) { + MyApplication* self = static_cast<MyApplication*>(user_data); + + g_autoptr(FlMethodResponse) response = nullptr; + if (strcmp(fl_method_call_get_name(method_call), "getBatteryLevel") == 0) { + response = get_battery_level(self); + } else { + response = FL_METHOD_RESPONSE(fl_method_not_implemented_response_new()); + } + + g_autoptr(GError) error = nullptr; + if (!fl_method_call_respond(method_call, response, &error)) { + g_warning("Failed to send response: %s", error->message); + } +} + +// Called when the Dart code starts listening for charging events. +static FlMethodErrorResponse* charging_listen_cb(FlEventChannel* channel, + FlValue* args, + gpointer user_data) { + MyApplication* self = static_cast<MyApplication*>(user_data); + + self->emit_charge_events = true; + update_charging_state(self); + + return nullptr; +} + +// Called when the Dart code stops listening for charging events. +static FlMethodErrorResponse* charging_cancel_cb(FlEventChannel* channel, + FlValue* args, + gpointer user_data) { + MyApplication* self = static_cast<MyApplication*>(user_data); + + self->emit_charge_events = false; + + return nullptr; +} + +// Creates the platform channels this application provides. +static void create_channels(MyApplication* self) { + FlEngine* engine = fl_view_get_engine(self->view); + FlBinaryMessenger* messenger = fl_engine_get_binary_messenger(engine); + g_autoptr(FlStandardMethodCodec) codec = fl_standard_method_codec_new(); + + self->battery_channel = fl_method_channel_new( + messenger, "samples.flutter.io/battery", FL_METHOD_CODEC(codec)); + fl_method_channel_set_method_call_handler( + self->battery_channel, battery_method_call_cb, self, nullptr); + + self->charging_channel = fl_event_channel_new( + messenger, "samples.flutter.io/charging", FL_METHOD_CODEC(codec)); + fl_event_channel_set_stream_handlers(self->charging_channel, + charging_listen_cb, charging_cancel_cb, + self, nullptr); +} + +// Implements GApplication::activate. +static void my_application_activate(GApplication* application) { + MyApplication* self = MY_APPLICATION(application); + GtkWindow* window = + GTK_WINDOW(gtk_application_window_new(GTK_APPLICATION(application))); + + // Use a header bar when running in GNOME as this is the common style used + // by applications and is the setup most users will be using (e.g. Ubuntu + // desktop). + // If running on X and not using GNOME then just use a traditional title bar + // in case the window manager does more exotic layout, e.g. tiling. + // If running on Wayland assume the header bar will work (may need changing + // if future cases occur). + gboolean use_header_bar = TRUE; +#ifdef GDK_WINDOWING_X11 + GdkScreen* screen = gtk_window_get_screen(window); + if (GDK_IS_X11_SCREEN(screen)) { + const gchar* wm_name = gdk_x11_screen_get_window_manager_name(screen); + if (g_strcmp0(wm_name, "GNOME Shell") != 0) { + use_header_bar = FALSE; + } + } +#endif + if (use_header_bar) { + GtkHeaderBar* header_bar = GTK_HEADER_BAR(gtk_header_bar_new()); + gtk_widget_show(GTK_WIDGET(header_bar)); + gtk_header_bar_set_title(header_bar, "platform_channel"); + gtk_header_bar_set_show_close_button(header_bar, TRUE); + gtk_window_set_titlebar(window, GTK_WIDGET(header_bar)); + } else { + gtk_window_set_title(window, "platform_channel"); + } + + gtk_window_set_default_size(window, 1280, 720); + gtk_widget_show(GTK_WIDGET(window)); + + g_autoptr(FlDartProject) project = fl_dart_project_new(); + fl_dart_project_set_dart_entrypoint_arguments( + project, self->dart_entrypoint_arguments); + + // Connect to UPower. + self->up_client = up_client_new(); + g_signal_connect_swapped(self->up_client, "device-added", + G_CALLBACK(up_device_added_cb), self); + g_signal_connect_swapped(self->up_client, "device-removed", + G_CALLBACK(up_device_removed_cb), self); + g_autoptr(GPtrArray) devices = up_client_get_devices(self->up_client); + for (guint i = 0; i < devices->len; i++) { + g_autoptr(UpDevice) device = + static_cast<UpDevice*>(g_ptr_array_index(devices, i)); + up_device_added_cb(self, device); + } + + self->view = fl_view_new(project); + gtk_widget_show(GTK_WIDGET(self->view)); + gtk_container_add(GTK_CONTAINER(window), GTK_WIDGET(self->view)); + + fl_register_plugins(FL_PLUGIN_REGISTRY(self->view)); + + // Create application specific platform channels. + create_channels(self); + + gtk_widget_grab_focus(GTK_WIDGET(self->view)); +} + +// Implements GApplication::local_command_line. +static gboolean my_application_local_command_line(GApplication* application, + gchar*** arguments, + int* exit_status) { + MyApplication* self = MY_APPLICATION(application); + // Strip out the first argument as it is the binary name. + self->dart_entrypoint_arguments = g_strdupv(*arguments + 1); + + g_autoptr(GError) error = nullptr; + if (!g_application_register(application, nullptr, &error)) { + g_warning("Failed to register: %s", error->message); + *exit_status = 1; + return TRUE; + } + + g_application_activate(application); + *exit_status = 0; + + return TRUE; +} + +// Implements GObject::dispose. +static void my_application_dispose(GObject* object) { + MyApplication* self = MY_APPLICATION(object); + + for (guint i = 0; i < self->battery_devices->len; i++) { + UpDevice* device = + static_cast<UpDevice*>(g_ptr_array_index(self->battery_devices, i)); + g_signal_handlers_disconnect_matched(device, G_SIGNAL_MATCH_DATA, 0, 0, + nullptr, nullptr, self); + } + g_signal_handlers_disconnect_matched(self->up_client, G_SIGNAL_MATCH_DATA, 0, + 0, nullptr, nullptr, self); + + g_clear_pointer(&self->dart_entrypoint_arguments, g_strfreev); + g_clear_object(&self->up_client); + g_clear_object(&self->battery_devices); + g_clear_object(&self->battery_channel); + g_clear_object(&self->charging_channel); + g_clear_pointer(&self->last_charge_event, g_free); + G_OBJECT_CLASS(my_application_parent_class)->dispose(object); +} + +static void my_application_class_init(MyApplicationClass* klass) { + G_APPLICATION_CLASS(klass)->activate = my_application_activate; + G_APPLICATION_CLASS(klass)->local_command_line = + my_application_local_command_line; + G_OBJECT_CLASS(klass)->dispose = my_application_dispose; +} + +static void my_application_init(MyApplication* self) { + self->battery_devices = g_ptr_array_new_with_free_func(g_object_unref); +} + +MyApplication* my_application_new() { + return MY_APPLICATION(g_object_new(my_application_get_type(), + "application-id", APPLICATION_ID, "flags", + G_APPLICATION_NON_UNIQUE, nullptr)); +}