Set accent color based on wallpaper

.github/workflows/main.yml

@@ -15,7 +15,7 @@ jobs:
     - name: Install Dependencies
       run: |
         apt update
-        apt install -y gettext gnome-settings-daemon-dev gsettings-desktop-schemas-dev libbamf3-dev libcanberra-dev libcanberra-gtk3-dev libclutter-1.0-dev libgee-0.8-dev libglib2.0-dev libgnome-desktop-3-dev libgranite-dev libgtk-3-dev libmutter-6-dev libplank-dev libxml2-utils meson valac valadoc
+        apt install -y gettext gnome-settings-daemon-dev gsettings-desktop-schemas-dev libbamf3-dev libcanberra-dev libcanberra-gtk3-dev libclutter-1.0-dev libgee-0.8-dev libglib2.0-dev libgnome-desktop-3-dev libgranite-dev libgtk-3-dev libmutter-6-dev libplank-dev libxml2-utils libgexiv2-dev meson valac valadoc
     - name: Build
       env:
         DESTDIR: out

README.md

@@ -14,6 +14,7 @@ You'll need the following dependencies:
 * libcanberra-gtk3-dev
 * libclutter-1.0-dev (>= 1.12.0)
 * libgee-0.8-dev
+* libgexiv2-dev
 * libglib2.0-dev (>= 2.44)
 * libgnome-desktop-3-dev
 * libgranite-dev (>= 5.4.0)

meson.build

@@ -92,6 +92,7 @@ granite_dep = dependency('granite', version: '>= 5.4.0')
 gnome_desktop_dep = dependency('gnome-desktop-3.0')
 gsd_dep = dependency('gnome-settings-daemon', version: '>= @0@'.format(gsd_version_required))
 m_dep = cc.find_library('m', required: false)
+gexiv2_dep = dependency('gexiv2')
 
 mutter_dep = []
 libmutter_dep = []
@@ -133,7 +134,7 @@ mutter_typelib_dir = libmutter_dep.get_pkgconfig_variable('typelibdir')
 add_project_arguments(vala_flags, language: 'vala')
 add_project_link_arguments(['-Wl,-rpath,@0@'.format(mutter_typelib_dir)], language: 'c')
 
-gala_base_dep = [glib_dep, gobject_dep, gio_dep, gmodule_dep, gee_dep, gtk_dep, plank_dep, mutter_dep, granite_dep, gnome_desktop_dep, m_dep, config_dep]
+gala_base_dep = [glib_dep, gobject_dep, gio_dep, gmodule_dep, gee_dep, gtk_dep, plank_dep, mutter_dep, granite_dep, gnome_desktop_dep, m_dep, gexiv2_dep, config_dep]
 
 subdir('data')
 subdir('lib')

src/AccentColor/AccentColorManager.vala

@@ -0,0 +1,166 @@
+/*
+ * Copyright 2021 elementary, Inc. (https://elementary.io)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA
+ *
+ * Authored by: Marius Meisenzahl <mariusmeisenzahl@gmail.com>
+ */
+
+ public class Gala.AccentColorManager : Object {
+    private const string INTERFACE_SCHEMA = "org.gnome.desktop.interface";
+    private const string STYLESHEET_KEY = "gtk-theme";
+    private const string TAG_ACCENT_COLOR = "Xmp.xmp.io.elementary.AccentColor";
+
+    private const string THEME_BLUE = "io.elementary.stylesheet.blueberry";
+    private const string THEME_MINT = "io.elementary.stylesheet.mint";
+    private const string THEME_GREEN = "io.elementary.stylesheet.lime";
+    private const string THEME_YELLOW = "io.elementary.stylesheet.banana";
+    private const string THEME_ORANGE = "io.elementary.stylesheet.orange";
+    private const string THEME_RED = "io.elementary.stylesheet.strawberry";
+    private const string THEME_PINK = "io.elementary.stylesheet.bubblegum";
+    private const string THEME_PURPLE = "io.elementary.stylesheet.grape";
+    private const string THEME_BROWN = "io.elementary.stylesheet.cocoa";
+    private const string THEME_GRAY = "io.elementary.stylesheet.slate";
+
+    private Gala.AccountsService? gala_accounts_service = null;
+
+    private Settings background_settings;
+    private Settings interface_settings;
+
+    private NamedColor[] theme_colors = {
+        new NamedColor ("Blue", THEME_BLUE),
+        new NamedColor ("Mint", THEME_MINT),
+        new NamedColor ("Green", THEME_GREEN),
+        new NamedColor ("Yellow", THEME_YELLOW),
+        new NamedColor ("Orange", THEME_ORANGE),
+        new NamedColor ("Red", THEME_RED),
+        new NamedColor ("Pink", THEME_PINK),
+        new NamedColor ("Purple", THEME_PURPLE),
+        new NamedColor ("Brown", THEME_BROWN),
+        new NamedColor ("Gray", THEME_GRAY)
+    };
+
+    construct {
+        background_settings = new Settings ("org.gnome.desktop.background");
+        interface_settings = new Settings (INTERFACE_SCHEMA);
+
+        string? user_path = null;
+        try {
+            FDO.Accounts? accounts_service = GLib.Bus.get_proxy_sync (
+                GLib.BusType.SYSTEM,
+               "org.freedesktop.Accounts",
+               "/org/freedesktop/Accounts"
+            );
+
+            user_path = accounts_service.find_user_by_name (GLib.Environment.get_user_name ());
+        } catch (Error e) {
+            critical (e.message);
+        }
+
+        if (user_path != null) {
+            try {
+                gala_accounts_service = GLib.Bus.get_proxy_sync (
+                    GLib.BusType.SYSTEM,
+                    "org.freedesktop.Accounts",
+                    user_path
+                );
+
+                ((DBusProxy)gala_accounts_service).g_properties_changed.connect (() => {
+                    update_accent_color ();
+                });
+            } catch (Error e) {
+                warning ("Unable to get AccountsService proxy, accent color preference may be incorrect");
+            }
+        }
+
+        background_settings.changed["picture-uri"].connect (update_accent_color);
+
+        update_accent_color ();
+    }
+
+    private void update_accent_color () {
+        bool set_accent_color_based_on_wallpaper = gala_accounts_service.prefers_accent_color == 0;
+
+        if (set_accent_color_based_on_wallpaper) {
+            var picture_uri = background_settings.get_string ("picture-uri");
+
+            var current_stylesheet = interface_settings.get_string (STYLESHEET_KEY);
+
+            debug ("Current wallpaper: %s", picture_uri);
+            debug ("Current stylesheet: %s", current_stylesheet);
+
+            NamedColor? new_color = null;
+            var accent_color_name = read_accent_color_name_from_exif (picture_uri);
+            if (accent_color_name != null) {
+                for (int i = 0; i < theme_colors.length; i++) {
+                    if (theme_colors[i].name == accent_color_name) {
+                        new_color = theme_colors[i];
+                        break;
+                    }
+                }
+            } else {
+                new_color = get_accent_color_of_picture_simple (picture_uri);
+            }
+
+            if (new_color != null && new_color.theme != current_stylesheet) {
+                debug ("New stylesheet: %s", new_color.theme);
+
+                interface_settings.set_string (
+                    STYLESHEET_KEY,
+                    new_color.theme
+                );
+            }
+        }
+    }
+
+    private string? read_accent_color_name_from_exif (string picture_uri) {
+        string path = "";
+        GExiv2.Metadata metadata;
+        try {
+            path = Filename.from_uri (picture_uri);
+            metadata = new GExiv2.Metadata ();
+            metadata.open_path (path);
+        } catch (Error e) {
+            warning ("Error parsing exif metadata of \"%s\": %s", path, e.message);
+            return null;
+        }
+
+        return metadata.get_tag_string (TAG_ACCENT_COLOR);
+    }
+
+    public NamedColor? get_accent_color_of_picture_simple (string picture_uri) {
+        NamedColor new_color = null;
+
+        var file = File.new_for_uri (picture_uri);
+
+        try {
+            var pixbuf = new Gdk.Pixbuf.from_file (file.get_path ());
+            var color_extractor = new ColorExtractor (pixbuf);
+
+            var palette = new Gee.ArrayList<Granite.Drawing.Color> ();
+            for (int i = 0; i < theme_colors.length; i++) {
+                palette.add (theme_colors[i].color);
+            }
+
+            var index = color_extractor.get_dominant_color_index (palette);
+            new_color = theme_colors[index];
+        } catch (Error e) {
+            warning (e.message);
+        }
+
+        return new_color;
+    }
+}

src/AccentColor/ColorExtractor.vala

@@ -0,0 +1,87 @@
+/*
+ * Copyright 2021 elementary, Inc. (https://elementary.io)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA
+ *
+ * Authored by: Marius Meisenzahl <mariusmeisenzahl@gmail.com>
+ */
+
+public class Gala.ColorExtractor : Object {
+    private const double PERCENTAGE_SAMPLE_PIXELS = 0.01;
+
+    public Gdk.Pixbuf pixbuf { get; construct set; }
+
+    private Gee.List<Granite.Drawing.Color> pixels;
+
+    public ColorExtractor (Gdk.Pixbuf pixbuf) {
+        Object (pixbuf: pixbuf);
+
+        pixels = convert_pixels_to_rgb (pixbuf.get_pixels_with_length (), pixbuf.has_alpha);
+    }
+
+    public int get_dominant_color_index (Gee.List<Granite.Drawing.Color> palette) {
+        int index = 0;
+        var matches = new double[palette.size];
+
+        pixels.foreach ((pixel) => {
+            for (int i = 0; i < palette.size; i++) {
+                var color = palette.get (i);
+
+                var distance = Math.sqrt (
+                    Math.pow ((pixel.R - color.R), 2) +
+                    Math.pow ((pixel.G - color.G), 2) +
+                    Math.pow ((pixel.B - color.B), 2)
+                );
+
+                if (distance > 0.25) {
+                    continue;
+                }
+
+                matches[i] += 1.0 - distance;
+            }
+
+            return true;
+        });
+
+        double best_match = double.MIN;
+        for (int i = 0; i < matches.length; i++) {
+            if (matches[i] > best_match) {
+                best_match = matches[i];
+                index = i;
+            }
+        }
+
+        return index;
+    }
+
+    private Gee.ArrayList<Granite.Drawing.Color> convert_pixels_to_rgb (uint8[] pixels, bool has_alpha) {
+        var list = new Gee.ArrayList<Granite.Drawing.Color> ();
+
+        int factor = 3 + (int) has_alpha;
+        int step_size = (int) (pixels.length / factor * PERCENTAGE_SAMPLE_PIXELS);
+
+        for (int i = 0; i < pixels.length / factor; i += step_size) {
+            int offset = i * factor;
+            double red = pixels[offset] / 255.0;
+            double green = pixels[offset + 1] / 255.0;
+            double blue = pixels[offset + 2] / 255.0;
+
+            list.add (new Granite.Drawing.Color (red, green, blue, 0.0));
+        }
+
+        return list;
+    }
+}

src/AccentColor/NamedColor.vala

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2021 elementary, Inc. (https://elementary.io)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA
+ *
+ * Authored by: Marius Meisenzahl <mariusmeisenzahl@gmail.com>
+ */
+
+public class Gala.NamedColor : Object {
+    public string name { get; construct set; }
+    public string theme { get; construct set; }
+    public Granite.Drawing.Color color { get; construct set; }
+
+    public NamedColor (string name, string theme) {
+        Object (
+            name: name,
+            theme: theme,
+            color: InternalUtils.get_accent_color_by_theme_name (theme)
+        );
+    }
+}

src/GalaAccountsServicePlugin.vala

@@ -0,0 +1,9 @@
+[DBus (name = "io.elementary.pantheon.AccountsService")]
+interface Gala.AccountsService : Object {
+    public abstract int prefers_accent_color { get; }
+}
+
+[DBus (name = "org.freedesktop.Accounts")]
+interface Gala.FDO.Accounts : Object {
+    public abstract string find_user_by_name (string username) throws GLib.Error;
+}

src/InternalUtils.vala

@@ -357,6 +357,24 @@ namespace Gala {
             );
         }
 
+        public static Granite.Drawing.Color get_accent_color_by_theme_name (string theme_name) {
+            var label_widget_path = new Gtk.WidgetPath ();
+            label_widget_path.append_type (GLib.Type.from_name ("label"));
+            label_widget_path.iter_set_object_name (-1, "selection");
+
+            var selection_style_context = new Gtk.StyleContext ();
+            unowned Gtk.CssProvider theme_provider = Gtk.CssProvider.get_named (theme_name, null);
+            selection_style_context.add_provider (theme_provider, Gtk.STYLE_PROVIDER_PRIORITY_USER);
+            selection_style_context.set_path (label_widget_path);
+
+            var rgba = (Gdk.RGBA) selection_style_context.get_property (
+                Gtk.STYLE_PROPERTY_BACKGROUND_COLOR,
+                Gtk.StateFlags.NORMAL
+            );
+
+            return new Granite.Drawing.Color.from_rgba (rgba);
+        }
+
         /**
          * Returns the workspaces geometry following the only_on_primary settings.
          */

src/WindowManager.vala

@@ -81,6 +81,8 @@ namespace Gala {
          */
         Zoom? zoom = null;
 
+        AccentColorManager accent_color_manager;
+
         Clutter.Actor? tile_preview;
 
         private Meta.Window? moving; //place for the window that is being moved over
@@ -292,6 +294,8 @@ namespace Gala {
 
             zoom = new Zoom (this);
 
+            accent_color_manager = new AccentColorManager ();
+
             // initialize plugins and add default components if no plugin overrides them
             var plugin_manager = PluginManager.get_default ();
             plugin_manager.initialize (this);