implement gtk4 theming over libadwaita apps

by overwriting the GTK4 CSS

src/applythemes.py

@@ -23,7 +23,7 @@ class BaseApplyThemes:
     """
     The base theme applying mechanism: write themes and settings to config files
     """
-    def applyThemes(self, props, gtk2Theme, gtk4Theme, kvantumTheme, kvantumThemeFilePath, cssText):
+    def applyThemes(self, props, gtk2Theme, gtk4Theme, kvantumTheme, kvantumThemeFilePath, cssText, gtk4ThemePath):
         gtkKeyFile = GLib.KeyFile()
 
         gtkKeyFile.set_string("Settings", "gtk-theme-name", gtk4Theme)
@@ -99,6 +99,9 @@ def applyThemes(self, props, gtk2Theme, gtk4Theme, kvantumTheme, kvantumThemeFil
         with open(os.path.join(GLib.get_user_config_dir(), "gtk-3.0", "gtk.css"), "w") as cssFile:
             cssFile.write(cssText)
         with open(os.path.join(GLib.get_user_config_dir(), "gtk-4.0", "gtk.css"), "w") as cssFile:
+            if gtk4ThemePath is not None:
+                cssFile.write("* {all: unset;}\n")
+                cssFile.write(f'@import url("{gtk4ThemePath}")\n')
             cssFile.write(cssText)
 
 class GSettingsApplyThemes(BaseApplyThemes):

src/getavailablethemes.py

@@ -1,15 +1,15 @@
 # Copyright (C) 2021  Popa Ioan Alexandru
-# 
+#
 # 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 2 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.
@@ -31,17 +31,16 @@ def uniquifySortedListStore(listStore):
 """
 The functions below create Gtk.ListStore's that store themes
 for use in SearchableThemeList's and have the following columns:
-1. A str column which holds the display name of the theme
-2. A str column which holds the underlying theme name
-3. (Optional, depends on which kind of themes are used)
- a) A GdkPixbuf.Pixbuf column which holds the theme's preview image
- b) A str column which holds the theme file path (for Kvantum)
+0. A str column which holds the display name of the theme
+1. A str column which holds the underlying theme name
+2. A str column which holds the theme file/folder path (those starting in "//" are fake ones that show a lack of a theme file)
+3. (Optional) A GdkPixbuf.Pixbuf column which holds the theme's preview image
 """
 
 def getAvailableGtk3Themes():
-    availableThemes = Gtk.ListStore(str, str, GdkPixbuf.Pixbuf)
+    availableThemes = Gtk.ListStore(str, str, str, GdkPixbuf.Pixbuf)
     availableThemes.set_sort_column_id(0, Gtk.SortType.ASCENDING)
-    availableThemes.append([" Adwaita", "Adwaita",
+    availableThemes.append([" Adwaita", "Adwaita", "//none",
         GdkPixbuf.Pixbuf.new_from_resource(
             "/com/github/alex11br/themechanger/adwaita.png"
         )
@@ -58,7 +57,7 @@ def getAvailableGtk3Themes():
                     availableThemes.append([
                         # we add a space to the beginning of the display name
                         # to create spacing between the theme preview image and the theme name text
-                        " "+f, f,
+                        " "+f, f, os.path.join(lookupPath, f),
                         GdkPixbuf.Pixbuf.new_from_file_at_size(
                             thumbnailFile, 120, 35
                         ) if os.path.isfile(thumbnailFile) else GdkPixbuf.Pixbuf.new_from_resource(
@@ -70,7 +69,7 @@ def getAvailableGtk3Themes():
     return uniquifySortedListStore(availableThemes)
 
 def getAvailableIconThemes():
-    availableThemes = Gtk.ListStore(str, str, GdkPixbuf.Pixbuf)
+    availableThemes = Gtk.ListStore(str, str, str, GdkPixbuf.Pixbuf)
     availableThemes.set_sort_column_id(0, Gtk.SortType.ASCENDING)
     lookupPaths = [
         os.path.join(GLib.get_user_data_dir(), "icons"),
@@ -89,7 +88,7 @@ def getAvailableIconThemes():
                         )
                         if (themeFileParser.get_string("Icon Theme", "Directories")):
                             availableThemes.append([
-                                themeFileParser.get_locale_string("Icon Theme", "Name"), f,
+                                themeFileParser.get_locale_string("Icon Theme", "Name"), f, os.path.join(lookupPath, f),
                                 iconTheme.load_icon(
                                     iconTheme.get_example_icon_name(),
                                     32, Gtk.IconLookupFlags.FORCE_SIZE
@@ -102,10 +101,10 @@ def getAvailableIconThemes():
     return uniquifySortedListStore(availableThemes)
 
 def getAvailableCursorThemes():
-    availableThemes = Gtk.ListStore(str, str, GdkPixbuf.Pixbuf)
+    availableThemes = Gtk.ListStore(str, str, str, GdkPixbuf.Pixbuf)
     availableThemes.set_sort_column_id(0, Gtk.SortType.ASCENDING)
     availableThemes.append([
-        "Default cursor", "default",
+        "Default cursor", "default", "//none",
         GdkPixbuf.Pixbuf.new_from_resource(
             "/com/github/alex11br/themechanger/defaultcursor.png"
         )
@@ -125,7 +124,7 @@ def getAvailableCursorThemes():
                             os.path.join(lookupPath, f, "index.theme"), GLib.KeyFileFlags.NONE
                         )
                         availableThemes.append([
-                            themeFileParser.get_locale_string("Icon Theme", "Name"), f,
+                            themeFileParser.get_locale_string("Icon Theme", "Name"), f, os.path.join(lookupPath, f),
                             pixbufFromXCursor(
                                 cursorPath
                             ) if os.path.isfile(cursorPath) else GdkPixbuf.Pixbuf.new_from_resource(
@@ -139,9 +138,9 @@ def getAvailableCursorThemes():
     return uniquifySortedListStore(availableThemes)
 
 def getAvailableGtk4Themes():
-    availableThemes = Gtk.ListStore(str, str)
+    availableThemes = Gtk.ListStore(str, str, str)
     availableThemes.set_sort_column_id(0, Gtk.SortType.ASCENDING)
-    availableThemes.append(["Adwaita", "Adwaita"])
+    availableThemes.append(["Adwaita", "Adwaita", "//none"])
     lookupPaths = [
         os.path.join(GLib.get_user_data_dir(), "themes"),
         os.path.join(GLib.get_home_dir(), ".themes"),
@@ -150,13 +149,13 @@ def getAvailableGtk4Themes():
         try:
             for f in os.listdir(lookupPath):
                 if os.path.isfile(os.path.join(lookupPath, f, "gtk-4.0", "gtk.css")):
-                    availableThemes.append([f, f])
+                    availableThemes.append([f, f, os.path.join(lookupPath, f)])
         except:
             pass
     return uniquifySortedListStore(availableThemes)
 
 def getAvailableGtk2Themes():
-    availableThemes = Gtk.ListStore(str, str)
+    availableThemes = Gtk.ListStore(str, str, str)
     availableThemes.set_sort_column_id(0, Gtk.SortType.ASCENDING)
     lookupPaths = [
         os.path.join(GLib.get_user_data_dir(), "themes"),
@@ -166,7 +165,7 @@ def getAvailableGtk2Themes():
         try:
             for f in os.listdir(lookupPath):
                 if os.path.isfile(os.path.join(lookupPath, f, "gtk-2.0", "gtkrc")):
-                    availableThemes.append([f, f])
+                    availableThemes.append([f, f, os.path.join(lookupPath, f)])
         except:
             pass
     return uniquifySortedListStore(availableThemes)

src/searchablethemelist.py

@@ -1,15 +1,15 @@
 # Copyright (C) 2021  Popa Ioan Alexandru
-# 
+#
 # 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 2 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.
@@ -38,8 +38,8 @@ def __init__(self, themesTreeViewModel, selectedTheme, onThemeSelectedCallback,
         if hasPixbuf:
             pixbufCell = Gtk.CellRendererPixbuf()
             themeColumn.pack_start(pixbufCell, False)
-            themeColumn.add_attribute(pixbufCell, "pixbuf", 2)
-            
+            themeColumn.add_attribute(pixbufCell, "pixbuf", 3)
+
         nameCell = Gtk.CellRendererText()
         themeColumn.pack_start(nameCell, True)
         themeColumn.add_attribute(nameCell, "text", 0)
@@ -54,10 +54,12 @@ def selectTheme(self):
                     self.themesTreeViewModelFiltered.get_path(row.iter),
                     None, False
                 )
+                self.selectedThemeRow = row
                 return
         # Maybe the selectedTheme isn't in the model; we'll properly handle this case here
         firstRow = self.themesTreeViewModelFiltered[0]
         self.selectedTheme = firstRow[1]
+        self.selectedThemeRow = firstRow
         self.themesTreeViewSelection.select_iter(firstRow.iter)
         self.themesTreeView.scroll_to_point(0, 0)
 
@@ -70,7 +72,7 @@ def setThemesTreeViewModel(self, themesTreeViewModel):
 
     def setScrolledWindowOverlayScrolling(self, state):
         self.themesScrolledWindow.set_overlay_scrolling(state)
-        
+
     def filterFunc(self, model, treeiter, data):
         return self.themesSearchEntry.get_text().lower() in model[treeiter][0].lower()
 
@@ -83,6 +85,7 @@ def onThemeSelected(self, selection):
         if not treeiter:
             return
         self.selectedTheme = model[treeiter][1]
+        self.selectedThemeRow = model[treeiter]
         if self.hasThemeFilePath:
             self.onThemeSelectedCallback(self.selectedTheme, model[treeiter][2])
         else:
@@ -93,4 +96,3 @@ def onChangeFilter(self, searchentry):
         self.themesTreeViewModelFiltered.refilter()
         # This handles the case in which the newly filtered model doen't have the selectedTheme anymore
         self.selectTheme()
-

src/window.py

@@ -246,6 +246,22 @@ def setDefaultCursor(self):
         defaultCursor = Gdk.Cursor.new_for_display(self.defaultDisplay, Gdk.CursorType.LEFT_PTR)
         self.defaultScreen.get_root_window().set_cursor(defaultCursor)
 
+    def getGtk4ThemeCssPath(self):
+        if self.anotherGtk4ThemeSwitch.get_active():
+            gtk4ThemeRoot = self.gtk4SearchableThemeList.selectedThemeRow[2]
+        else:
+            gtk4ThemeRoot = self.gtkSearchableThemeList.selectedThemeRow[2]
+
+        if gtk4ThemeRoot[:2] == "//":
+            return None
+
+        gtk4ThemeCssPath = os.path.join(gtk4ThemeRoot, "gtk-4.0", "gtk-dark.css" if self.gtkProps.gtk_application_prefer_dark_theme else "gtk.css")
+        if not os.path.isfile(gtk4ThemeCssPath):
+            gtk4ThemeCssPath = os.path.join(gtk4ThemeRoot, "gtk-4.0", "gtk.css")
+            if not os.path.isfile(gtk4ThemeCssPath):
+                return None
+        return gtk4ThemeCssPath
+
     def onGtkThemeChanged(self, themename):
         self.onSettingChanged()
 
@@ -380,7 +396,8 @@ def applySettings(self, *args):
                 gtk4Theme=self.gtk4ThemeName,
                 kvantumTheme=self.kvantumThemeName,
                 kvantumThemeFilePath=self.kvantumThemeFilePath,
-                cssText=self.cssTextBuffer.props.text
+                cssText=self.cssTextBuffer.props.text,
+                gtk4ThemePath=self.getGtk4ThemeCssPath()
             )
         except Exception as err:
             showErrorDialog("Error: Could not apply settings", str(err))

src/window.ui

@@ -248,7 +248,7 @@
                                       <object class="GtkLabel">
                                         <property name="visible">True</property>
                                         <property name="can-focus">False</property>
-                                        <property name="label" translatable="yes">Instantaneous theme changing is supported. This means that setting another theme for GTK2 or GTK4 won't have any effect.</property>
+                                        <property name="label" translatable="yes">Instantaneous theme changing is supported. This means that setting another theme for GTK2 won't have any effect.</property>
                                         <property name="wrap">True</property>
                                       </object>
                                       <packing>