Add soft light border in dark theme

assets/handy-window-dark.css

@@ -0,0 +1,16 @@
+window.csd.unified:not(.solid-csd):not(.fullscreen):not(.maximized) decoration-overlay {
+  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.07);
+}
+
+window.csd.unified:not(.solid-csd):not(.fullscreen):not(.maximized) headerbar {
+  box-shadow: none;
+}
+
+decoration {
+  box-shadow: 0 3px 9px 1px rgba(0,0,0,.5);
+}
+
+decoration:backdrop {
+  box-shadow: 0 3px 9px 1px transparent,
+              0 2px 6px 2px rgba(0,0,0,.2);
+}

example/linux/flutter/generated_plugin_registrant.cc

@@ -8,6 +8,7 @@
 
 #include <handy_window/handy_window_plugin.h>
 #include <url_launcher_linux/url_launcher_plugin.h>
+#include <yaru/yaru_plugin.h>
 
 void fl_register_plugins(FlPluginRegistry* registry) {
   g_autoptr(FlPluginRegistrar) handy_window_registrar =
@@ -16,4 +17,7 @@ void fl_register_plugins(FlPluginRegistry* registry) {
   g_autoptr(FlPluginRegistrar) url_launcher_linux_registrar =
       fl_plugin_registry_get_registrar_for_plugin(registry, "UrlLauncherPlugin");
   url_launcher_plugin_register_with_registrar(url_launcher_linux_registrar);
+  g_autoptr(FlPluginRegistrar) yaru_registrar =
+      fl_plugin_registry_get_registrar_for_plugin(registry, "YaruPlugin");
+  yaru_plugin_register_with_registrar(yaru_registrar);
 }

example/linux/flutter/generated_plugins.cmake

@@ -5,6 +5,7 @@
 list(APPEND FLUTTER_PLUGIN_LIST
   handy_window
   url_launcher_linux
+  yaru
 )
 
 list(APPEND FLUTTER_FFI_PLUGIN_LIST

linux/CMakeLists.txt

@@ -8,12 +8,17 @@ set(PLUGIN_NAME "handy_window_plugin")
 
 add_library(${PLUGIN_NAME} SHARED
   "handy_window_plugin.cc"
+  "settings/handy_gnome_settings.cc"
+  "settings/handy_settings_portal.cc"
+  "settings/handy_settings.cc"
 )
 apply_standard_settings(${PLUGIN_NAME})
 set_target_properties(${PLUGIN_NAME} PROPERTIES
   CXX_VISIBILITY_PRESET hidden)
 target_compile_options(${PLUGIN_NAME} PRIVATE -Wall -Wextra -Werror)
 target_compile_definitions(${PLUGIN_NAME} PRIVATE FLUTTER_PLUGIN_IMPL)
+target_include_directories(${PLUGIN_NAME} PRIVATE
+  "${CMAKE_CURRENT_SOURCE_DIR}/settings")
 target_include_directories(${PLUGIN_NAME} INTERFACE
   "${CMAKE_CURRENT_SOURCE_DIR}/include")
 target_link_libraries(${PLUGIN_NAME} PRIVATE flutter)

linux/handy_window_plugin.cc

@@ -8,6 +8,8 @@
 
 #include <functional>
 
+#include "handy_settings.h"
+
 #define _HANDY_INSIDE
 #include "hdy-window-mixin-private.h"
 #undef _HANDY_INSIDE
@@ -163,6 +165,37 @@ static gboolean use_csd(GtkWidget* window) {
   return true;
 }
 
+static void load_css(HandySettings* settings) {
+  GdkScreen* screen = gdk_screen_get_default();
+  gpointer css_provider =
+      g_object_get_data(G_OBJECT(screen), "_handy_window_css_provider_");
+
+  if (css_provider == nullptr) {
+    css_provider = gtk_css_provider_new();
+    gtk_style_context_add_provider_for_screen(
+        screen, GTK_STYLE_PROVIDER(css_provider),
+        GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
+    g_object_set_data_full(G_OBJECT(screen), "_handy_window_css_provider_",
+                           css_provider, g_object_unref);
+  }
+
+  HandyColorScheme color_scheme = handy_settings_get_color_scheme(settings);
+
+  g_autoptr(GError) error = nullptr;
+  g_autofree gchar* exe_path = g_file_read_link("/proc/self/exe", &error);
+  g_autofree gchar* app_path = g_path_get_dirname(exe_path);
+  const gchar* asset_path = "data/flutter_assets/packages/handy_window/assets";
+  const gchar* css_file = color_scheme == HANDY_COLOR_SCHEME_DARK
+                              ? "handy-window-dark.css"
+                              : "handy-window.css";
+  g_autofree gchar* css_path =
+      g_build_filename(app_path, asset_path, css_file, nullptr);
+  if (!gtk_css_provider_load_from_path(GTK_CSS_PROVIDER(css_provider), css_path,
+                                       &error)) {
+    g_warning("%s: %s", css_path, error->message);
+  }
+}
+
 static void setup_handy_window(FlView* view) {
   GtkWidget* window = gtk_widget_get_toplevel(GTK_WIDGET(view));
 
@@ -242,6 +275,12 @@ static void setup_handy_window(FlView* view) {
     gtk_widget_show(header_bar);
   }
   gtk_widget_show(GTK_WIDGET(view));
+
+  // css
+  HandySettings* settings = handy_settings_new();
+  load_css(settings);
+  g_signal_connect_object(settings, "changed", G_CALLBACK(load_css), settings,
+                          G_CONNECT_SWAPPED);
 }
 
 void handy_window_plugin_register_with_registrar(FlPluginRegistrar* registrar) {

linux/settings/LICENCE

@@ -0,0 +1,25 @@
+Copyright 2013 The Flutter Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+    * Neither the name of Google Inc. nor the names of its
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

linux/settings/README.md

@@ -0,0 +1,4 @@
+# HandySettings
+
+Based on FlSettings, FlSettingsPortal, and FlGnomeSettings:
+https://github.com/flutter/engine/tree/main/shell/platform/linux

linux/settings/handy_gnome_settings.cc

@@ -0,0 +1,120 @@
+// 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 "handy_gnome_settings.h"
+
+#include <gio/gio.h>
+#include <glib.h>
+
+static constexpr char kDesktopInterfaceSchema[] = "org.gnome.desktop.interface";
+static constexpr char kDesktopGtkThemeKey[] = "gtk-theme";
+
+static constexpr char kGtkThemeDarkSuffix[] = "-dark";
+static constexpr char kInterfaceSettings[] = "interface-settings";
+
+struct _HandyGnomeSettings {
+  GObject parent_instance;
+
+  GSettings* interface_settings;
+};
+
+enum { kProp0, kPropInterfaceSettings, kPropLast };
+
+static void handy_gnome_settings_iface_init(HandySettingsInterface* iface);
+
+G_DEFINE_TYPE_WITH_CODE(HandyGnomeSettings, handy_gnome_settings, G_TYPE_OBJECT,
+                        G_IMPLEMENT_INTERFACE(handy_settings_get_type(),
+                                              handy_gnome_settings_iface_init))
+
+static HandyColorScheme handy_gnome_settings_get_color_scheme(
+    HandySettings* settings) {
+  HandyGnomeSettings* self = HANDY_GNOME_SETTINGS(settings);
+
+  HandyColorScheme color_scheme = HANDY_COLOR_SCHEME_LIGHT;
+
+  if (self->interface_settings != nullptr) {
+    // check whether org.gnome.desktop.interface.gtk-theme ends with "-dark"
+    g_autofree gchar* value =
+        g_settings_get_string(self->interface_settings, kDesktopGtkThemeKey);
+    if (g_str_has_suffix(value, kGtkThemeDarkSuffix)) {
+      color_scheme = HANDY_COLOR_SCHEME_DARK;
+    }
+  }
+  return color_scheme;
+}
+
+static void handy_gnome_settings_set_interface_settings(
+    HandyGnomeSettings* self, GSettings* settings) {
+  g_return_if_fail(G_IS_SETTINGS(settings));
+
+  g_signal_connect_object(settings, "changed::gtk-theme",
+                          G_CALLBACK(handy_settings_emit_changed), self,
+                          G_CONNECT_SWAPPED);
+
+  self->interface_settings = G_SETTINGS(g_object_ref(settings));
+}
+
+static void handy_gnome_settings_set_property(GObject* object, guint prop_id,
+                                              const GValue* value,
+                                              GParamSpec* pspec) {
+  HandyGnomeSettings* self = HANDY_GNOME_SETTINGS(object);
+  switch (prop_id) {
+    case kPropInterfaceSettings:
+      handy_gnome_settings_set_interface_settings(
+          self, G_SETTINGS(g_value_get_object(value)));
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
+      break;
+  }
+}
+
+static void handy_gnome_settings_dispose(GObject* object) {
+  HandyGnomeSettings* self = HANDY_GNOME_SETTINGS(object);
+
+  g_clear_object(&self->interface_settings);
+
+  G_OBJECT_CLASS(handy_gnome_settings_parent_class)->dispose(object);
+}
+
+static void handy_gnome_settings_class_init(HandyGnomeSettingsClass* klass) {
+  GObjectClass* object_class = G_OBJECT_CLASS(klass);
+  object_class->dispose = handy_gnome_settings_dispose;
+  object_class->set_property = handy_gnome_settings_set_property;
+
+  g_object_class_install_property(
+      object_class, kPropInterfaceSettings,
+      g_param_spec_object(
+          kInterfaceSettings, kInterfaceSettings, kDesktopInterfaceSchema,
+          g_settings_get_type(),
+          static_cast<GParamFlags>(G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY |
+                                   G_PARAM_STATIC_STRINGS)));
+}
+
+static void handy_gnome_settings_iface_init(HandySettingsInterface* iface) {
+  iface->get_color_scheme = handy_gnome_settings_get_color_scheme;
+}
+
+static void handy_gnome_settings_init(HandyGnomeSettings*) {}
+
+static GSettings* create_settings(const gchar* schema_id) {
+  GSettings* settings = nullptr;
+  GSettingsSchemaSource* source = g_settings_schema_source_get_default();
+  if (source != nullptr) {
+    g_autoptr(GSettingsSchema) schema =
+        g_settings_schema_source_lookup(source, schema_id, TRUE);
+    if (schema != nullptr) {
+      settings = g_settings_new_full(schema, nullptr, nullptr);
+    }
+  }
+  return settings;
+}
+
+HandySettings* handy_gnome_settings_new() {
+  g_autoptr(GSettings) interface_settings =
+      create_settings(kDesktopInterfaceSchema);
+  return HANDY_SETTINGS(g_object_new(handy_gnome_settings_get_type(),
+                                     kInterfaceSettings, interface_settings,
+                                     nullptr));
+}

linux/settings/handy_gnome_settings.h

@@ -0,0 +1,26 @@
+// 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.
+
+#ifndef HANDY_GNOME_SETTINGS_H_
+#define HANDY_GNOME_SETTINGS_H_
+
+#include "handy_settings.h"
+
+G_BEGIN_DECLS
+
+G_DECLARE_FINAL_TYPE(HandyGnomeSettings, handy_gnome_settings, HANDY,
+                     GNOME_SETTINGS, GObject);
+
+/**
+ * handy_gnome_settings_new:
+ *
+ * Creates a new settings instance for GNOME.
+ *
+ * Returns: a new #HandySettings.
+ */
+HandySettings* handy_gnome_settings_new();
+
+G_END_DECLS
+
+#endif  // HANDY_GNOME_SETTINGS_H_

linux/settings/handy_settings.cc

@@ -0,0 +1,50 @@
+// 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 "handy_settings.h"
+
+#include "handy_gnome_settings.h"
+#include "handy_settings_portal.h"
+
+G_DEFINE_INTERFACE(HandySettings, handy_settings, G_TYPE_OBJECT)
+
+enum {
+  kSignalChanged,
+  kSignalLastSignal,
+};
+
+static guint signals[kSignalLastSignal];
+
+static void handy_settings_default_init(HandySettingsInterface* iface) {
+  /**
+   * HandySettings::changed:
+   * @settings: an #HandySettings
+   *
+   * This signal is emitted after the settings have been changed.
+   */
+  signals[kSignalChanged] =
+      g_signal_new("changed", G_TYPE_FROM_INTERFACE(iface), G_SIGNAL_RUN_LAST,
+                   0, NULL, NULL, NULL, G_TYPE_NONE, 0);
+}
+
+HandyColorScheme handy_settings_get_color_scheme(HandySettings* self) {
+  return HANDY_SETTINGS_GET_IFACE(self)->get_color_scheme(self);
+}
+
+void handy_settings_emit_changed(HandySettings* self) {
+  g_return_if_fail(HANDY_IS_SETTINGS(self));
+  g_signal_emit(self, signals[kSignalChanged], 0);
+}
+
+HandySettings* handy_settings_new() {
+  g_autoptr(HandySettingsPortal) portal = handy_settings_portal_new();
+
+  g_autoptr(GError) error = nullptr;
+  if (!handy_settings_portal_start(portal, &error)) {
+    g_debug("XDG desktop portal settings unavailable: %s", error->message);
+    return handy_gnome_settings_new();
+  }
+
+  return HANDY_SETTINGS(g_object_ref(portal));
+}