| // 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_settings_plugin.h" |
| |
| #include <gmodule.h> |
| #include <gtk/gtk.h> |
| #include <math.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/settings"; |
| static constexpr char kTextScaleFactorKey[] = "textScaleFactor"; |
| static constexpr char kAlwaysUse24HourFormatKey[] = "alwaysUse24HourFormat"; |
| static constexpr char kPlatformBrightnessKey[] = "platformBrightness"; |
| static constexpr char kPlatformBrightnessLight[] = "light"; |
| static constexpr char kPlatformBrightnessDark[] = "dark"; |
| |
| static constexpr char kDesktopInterfaceSchema[] = "org.gnome.desktop.interface"; |
| static constexpr char kDesktopTextScalingFactorKey[] = "text-scaling-factor"; |
| static constexpr char kDesktopClockFormatKey[] = "clock-format"; |
| static constexpr char kClockFormat24Hour[] = "24h"; |
| |
| enum class Brightness { Light, Dark }; |
| |
| struct _FlSettingsPlugin { |
| GObject parent_instance; |
| |
| FlBasicMessageChannel* channel; |
| |
| GSettings* interface_settings; |
| |
| GArray* connections; |
| }; |
| |
| G_DEFINE_TYPE(FlSettingsPlugin, fl_settings_plugin, G_TYPE_OBJECT) |
| |
| // The color brightness calculation has been adapted from theme_data.dart: |
| // https://github.com/flutter/flutter/blob/8fe4cc79648a952f9c7e49a5248756c2ff98fa3b/packages/flutter/lib/src/material/theme_data.dart#L1470-L1488 |
| |
| // See <https://www.w3.org/TR/WCAG20/#relativeluminancedef>. |
| static gdouble linearize_color_component(gdouble component) { |
| if (component <= 0.03928) { |
| return component / 12.92; |
| } |
| return pow((component + 0.055) / 1.055, 2.4); |
| } |
| |
| // See <https://en.wikipedia.org/wiki/Relative_luminance>. |
| gdouble compute_luminance(GdkRGBA* color) { |
| gdouble r = linearize_color_component(color->red); |
| gdouble g = linearize_color_component(color->green); |
| gdouble b = linearize_color_component(color->blue); |
| return 0.2126 * r + 0.7152 * g + 0.0722 * b; |
| } |
| |
| static Brightness estimate_brightness_for_color(GdkRGBA* color) { |
| gdouble relative_luminance = compute_luminance(color); |
| |
| // See <https://www.w3.org/TR/WCAG20/#contrast-ratiodef> and |
| // <https://material.io/go/design-theming#color-color-palette>. |
| const gdouble kThreshold = 0.15; |
| if ((relative_luminance + 0.05) * (relative_luminance + 0.05) > kThreshold) { |
| return Brightness::Light; |
| } |
| return Brightness::Dark; |
| } |
| |
| static bool is_dark_theme() { |
| // GTK doesn't have a specific flag for dark themes, so we check if the |
| // style text color is light or dark |
| GList* windows = gtk_window_list_toplevels(); |
| if (windows == nullptr) { |
| return false; |
| } |
| |
| GtkWidget* window = GTK_WIDGET(windows->data); |
| g_list_free(windows); |
| |
| GdkRGBA text_color; |
| GtkStyleContext* style = gtk_widget_get_style_context(window); |
| gtk_style_context_get_color(style, GTK_STATE_FLAG_NORMAL, &text_color); |
| return estimate_brightness_for_color(&text_color) == Brightness::Light; |
| } |
| |
| // Sends the current settings to the Flutter engine. |
| static void update_settings(FlSettingsPlugin* self) { |
| gdouble scaling_factor = 1.0; |
| gboolean always_use_24hr = FALSE; |
| const gchar* platform_brightness = kPlatformBrightnessLight; |
| |
| if (self->interface_settings != nullptr) { |
| scaling_factor = g_settings_get_double(self->interface_settings, |
| kDesktopTextScalingFactorKey); |
| g_autofree gchar* clock_format = |
| g_settings_get_string(self->interface_settings, kDesktopClockFormatKey); |
| always_use_24hr = g_strcmp0(clock_format, kClockFormat24Hour) == 0; |
| } |
| |
| if (is_dark_theme()) { |
| platform_brightness = kPlatformBrightnessDark; |
| } |
| |
| g_autoptr(FlValue) message = fl_value_new_map(); |
| fl_value_set_string_take(message, kTextScaleFactorKey, |
| fl_value_new_float(scaling_factor)); |
| fl_value_set_string_take(message, kAlwaysUse24HourFormatKey, |
| fl_value_new_bool(always_use_24hr)); |
| fl_value_set_string_take(message, kPlatformBrightnessKey, |
| fl_value_new_string(platform_brightness)); |
| fl_basic_message_channel_send(self->channel, message, nullptr, nullptr, |
| nullptr); |
| } |
| |
| static void fl_settings_plugin_dispose(GObject* object) { |
| FlSettingsPlugin* self = FL_SETTINGS_PLUGIN(object); |
| |
| for (guint i = 0; i < self->connections->len; i += 1) { |
| g_signal_handler_disconnect(self->interface_settings, |
| g_array_index(self->connections, gulong, i)); |
| } |
| g_array_unref(self->connections); |
| g_clear_object(&self->channel); |
| g_clear_object(&self->interface_settings); |
| |
| G_OBJECT_CLASS(fl_settings_plugin_parent_class)->dispose(object); |
| } |
| |
| static void fl_settings_plugin_class_init(FlSettingsPluginClass* klass) { |
| G_OBJECT_CLASS(klass)->dispose = fl_settings_plugin_dispose; |
| } |
| |
| static void fl_settings_plugin_init(FlSettingsPlugin* self) {} |
| |
| FlSettingsPlugin* fl_settings_plugin_new(FlBinaryMessenger* messenger) { |
| g_return_val_if_fail(FL_IS_BINARY_MESSENGER(messenger), nullptr); |
| |
| FlSettingsPlugin* self = |
| FL_SETTINGS_PLUGIN(g_object_new(fl_settings_plugin_get_type(), nullptr)); |
| |
| g_autoptr(FlJsonMessageCodec) codec = fl_json_message_codec_new(); |
| self->channel = fl_basic_message_channel_new(messenger, kChannelName, |
| FL_MESSAGE_CODEC(codec)); |
| self->connections = g_array_new(FALSE, FALSE, sizeof(gulong)); |
| |
| return self; |
| } |
| |
| void fl_settings_plugin_start(FlSettingsPlugin* self) { |
| g_return_if_fail(FL_IS_SETTINGS_PLUGIN(self)); |
| |
| // If we are on GNOME, get settings from GSettings. |
| GSettingsSchemaSource* source = g_settings_schema_source_get_default(); |
| if (source != nullptr) { |
| g_autoptr(GSettingsSchema) schema = |
| g_settings_schema_source_lookup(source, kDesktopInterfaceSchema, FALSE); |
| if (schema != nullptr) { |
| self->interface_settings = g_settings_new_full(schema, nullptr, nullptr); |
| gulong new_connections[] = { |
| g_signal_connect_object( |
| self->interface_settings, "changed::text-scaling-factor", |
| G_CALLBACK(update_settings), self, G_CONNECT_SWAPPED), |
| g_signal_connect_object( |
| self->interface_settings, "changed::clock-format", |
| G_CALLBACK(update_settings), self, G_CONNECT_SWAPPED), |
| g_signal_connect_object( |
| self->interface_settings, "changed::gtk-theme", |
| G_CALLBACK(update_settings), self, G_CONNECT_SWAPPED), |
| }; |
| g_array_append_vals(self->connections, new_connections, |
| sizeof(new_connections) / sizeof(gulong)); |
| } |
| } |
| |
| update_settings(self); |
| } |