Introduce generic theme variants.

data/darktableconfig.xml.in

@@ -40,6 +40,37 @@
     <default>false</default>
     <shortdescription>modify theme with user tweaks</shortdescription>
   </dtconfig>
+  <dtconfig common="yes">
+    <name>themes/rounded-header</name>
+    <type>bool</type>
+    <default>false</default>
+    <shortdescription>use rounded module's header</shortdescription>
+  </dtconfig>
+  <dtconfig common="yes">
+    <name>themes/focused-module-border</name>
+    <type>bool</type>
+    <default>false</default>
+    <shortdescription>use small border around module</shortdescription>
+  </dtconfig>
+  <dtconfig common="yes">
+    <name>themes/expanded-module-border</name>
+    <type>bool</type>
+    <default>false</default>
+    <shortdescription>use small border around module</shortdescription>
+  </dtconfig>
+  <dtconfig common="yes">
+    <name>themes/colored-accent</name>
+    <type>int</type>
+    <default>0</default>
+    <shortdescription>use colored accent for some UI elements</shortdescription>
+  </dtconfig>
+  <dtconfig common="yes">
+    <name>themes/condensed</name>
+    <type>bool</type>
+    <default>false</default>
+    <shortdescription>condensed panels' controls</shortdescription>
+    <longdescription>use condensed panels' controls in all views</longdescription>
+  </dtconfig>
   <dtconfig prefs="misc" section="accel">
     <name>accel/prefer_focused</name>
     <type>bool</type>
@@ -161,13 +192,6 @@
     <shortdescription>marker shape</shortdescription>
     <longdescription>the shape of the slider marker</longdescription>
   </dtconfig>
-  <dtconfig prefs="misc" section="interface" common="yes" restart="true">
-    <name>themes/condensed</name>
-    <type>bool</type>
-    <default>false</default>
-    <shortdescription>condensed panels' controls</shortdescription>
-    <longdescription>use condensed panels' controls in all views</longdescription>
-  </dtconfig>
   <dtconfig prefs="misc" section="interface" common="yes">
     <name>darkroom/ui/auto_module_name_update</name>
     <type>bool</type>

data/themes/chunk-blue-accent-color.css

@@ -0,0 +1,4 @@
+
+@define-color active_module_icon_fg @accent_blue;
+
+@import url("chunk-colored-accent.css");

data/themes/chunk-blue-expanded-module-border.css

@@ -0,0 +1,4 @@
+
+@define-color plugin_expanded_border_color @accent_blue;
+
+@import url("chunk-expanded-module-border.css");

data/themes/chunk-blue-focused-module-border.css

@@ -0,0 +1,4 @@
+
+@define-color plugin_focus_border_color @accent_blue;
+
+@import url("chunk-focused-module-border.css");

data/themes/chunk-colored-accent.css

@@ -0,0 +1,19 @@
+
+#right #module-header > button:first-child:checked,
+#right #basics-header-box > button:first-child:checked
+{
+  color: @active_module_icon_fg;
+}
+
+#right #module-header > button:first-child:hover,
+#right #basics-header-box > button:first-child:hover
+{
+  background-color: black;
+}
+
+#right > box:last-child #module-header
+{
+ background-color: @bg_color;
+ border-radius: 0px;
+ margin-right: 0.9em;
+}

data/themes/chunk-condensed.css

@@ -34,3 +34,12 @@
    min-height: 12px;
    font-size: 0.95em;
 }
+
+#left #module-header,
+#right #module-header,
+#right #basics-header-box
+{
+  border-radius: 0px;
+  margin: 0px;
+  padding: 4px;
+}

data/themes/chunk-dark-expanded-module-border.css

@@ -0,0 +1,4 @@
+
+@define-color plugin_expanded_border_color shade(@plugin_bg_color, 0.5);
+
+@import url("chunk-expanded-module-border.css");

data/themes/chunk-dark-focused-module-border.css

@@ -0,0 +1,4 @@
+
+@define-color plugin_focus_border_color shade(@plugin_bg_color, 0.5);
+
+@import url("chunk-focused-module-border.css");

data/themes/chunk-expanded-module-border.css

@@ -0,0 +1,13 @@
+
+/* ensure space for border is reserved for all modules */
+#iop-expander
+{
+  border: 0.1em solid @plugin_bg_color;
+  margin: 0.2em 0.2em 0 0.2em;
+}
+
+/* border for expanded modules */
+#iop-expander.dt_module_expanded
+{
+  border: 0.1em solid @plugin_expanded_border_color;
+}

data/themes/chunk-focused-module-border.css

@@ -0,0 +1,13 @@
+
+/* ensure space for border is reserved for all modules */
+#iop-expander
+{
+  border: 0.1em solid @plugin_bg_color;
+  margin: 0.2em 0.2em 0 0.2em;
+}
+
+/* border for focused modules */
+#iop-expander.dt_module_expanded.dt_module_focus
+{
+  border: 0.1em solid @plugin_focus_border_color;
+}

data/themes/chunk-green-accent-color.css

@@ -0,0 +1,4 @@
+
+@define-color active_module_icon_fg @accent_green;
+
+@import url("chunk-colored-accent.css");

data/themes/chunk-green-expanded-module-border.css

@@ -0,0 +1,4 @@
+
+@define-color plugin_expanded_border_color @accent_green;
+
+@import url("chunk-expanded-module-border.css");

data/themes/chunk-green-focused-module-border.css

@@ -0,0 +1,4 @@
+
+@define-color plugin_focus_border_color @accent_green;
+
+@import url("chunk-focused-module-border.css");

data/themes/chunk-light-expanded-module-border.css

@@ -0,0 +1,4 @@
+
+@define-color plugin_expanded_border_color shade(@plugin_bg_color, 2.0);
+
+@import url("chunk-expanded-module-border.css");

data/themes/chunk-light-focused-module-border.css

@@ -0,0 +1,4 @@
+
+@define-color plugin_focus_border_color shade(@plugin_bg_color, 2.0);
+
+@import url("chunk-focused-module-border.css");

data/themes/chunk-orange-accent-color.css

@@ -0,0 +1,4 @@
+
+@define-color active_module_icon_fg @accent_orange;
+
+@import url("chunk-colored-accent.css");

data/themes/chunk-orange-expanded-module-border.css

@@ -0,0 +1,4 @@
+
+@define-color plugin_expanded_border_color @accent_orange;
+
+@import url("chunk-expanded-module-border.css");

data/themes/chunk-orange-focused-module-border.css

@@ -0,0 +1,4 @@
+
+@define-color plugin_focus_border_color @accent_orange;
+
+@import url("chunk-focused-module-border.css");

data/themes/chunk-rounded-header.css

@@ -0,0 +1,28 @@
+
+@define-color header_color shade(@plugin_bg_color, 0.8);
+@define-color header_color_bg shade(@plugin_bg_color, 1.1);
+
+#left #module-header,
+#right #module-header,
+#right #basics-header-box
+{
+  background-color: @header_color;
+  border-radius: 0px;
+}
+
+#left #module-header
+{
+  border-top-right-radius: 15px;
+}
+
+#right #module-header,
+#right #basics-header-box
+{
+  border-top-left-radius: 15px;
+}
+
+#iop-expander,
+.dt_module_expanded
+{
+   background-color: @header_color_bg;
+}

data/themes/chunk-yellow-accent-color.css

@@ -0,0 +1,4 @@
+
+@define-color active_module_icon_fg @accent_yellow;
+
+@import url("chunk-colored-accent.css");

data/themes/chunk-yellow-expanded-module-border.css

@@ -0,0 +1,4 @@
+
+@define-color plugin_expanded_border_color @accent_yellow;
+
+@import url("chunk-expanded-module-border.css");

data/themes/chunk-yellow-focused-module-border.css

@@ -0,0 +1,4 @@
+
+@define-color plugin_focus_border_color @accent_yellow;
+
+@import url("chunk-focused-module-border.css");

data/themes/darktable.css

@@ -231,6 +231,12 @@ Why that? Just because it's a developer choice and most classes use underscore i
 @define-color colorlabel_yellow rgb(255,180,0);
 @define-color colorlabel_purple rgb(230,0,230);
 
+/* pastel colors for the variants (module borders and active module) */
+@define-color accent_green #C1E1C5;
+@define-color accent_blue #9FBFE2;
+@define-color accent_yellow #E6E6A1;
+@define-color accent_orange #E6C2A1;
+
 /* Reset GTK defaults - Otherwise dt inherits Adwaita default theme dark */
 *
 {
@@ -1339,6 +1345,13 @@ filechooser row:hover .sidebar-icon
   padding: 0.14em 0.84em;
 }
 
+#theme-variant
+{
+  margin-left: 2em;
+  padding-left: 0.5em;
+  min-height: 1.5em;
+}
+
 /*--------------------
   - Quick access tab -
   --------------------*/

src/gui/gtk.c

@@ -3709,6 +3709,67 @@ void dt_gui_load_theme(const char *theme)
     _add_theme_import(&themecss, datadir, "themes", "chunk-condensed.css");
   }
 
+  // chunk-rounded-header
+
+  if(dt_conf_get_bool("themes/rounded-header"))
+  {
+    _add_theme_import(&themecss, datadir, "themes", "chunk-rounded-header.css");
+  }
+
+  // chunk-colored-accent
+
+  int index = dt_conf_get_int("themes/accent-color");
+
+  if(index > 0)
+  {
+    const char *colors[] =
+        {
+            "none",
+            "green",
+            "blue",
+            "yellow",
+            "orange"
+        };
+
+    char *chunk = g_strdup_printf
+      ("chunk-%s-accent-color.css",
+       colors[index]);
+    _add_theme_import(&themecss, datadir, "themes", chunk);
+    g_free(chunk);
+  }
+
+  // focused module border
+
+  const char *border_colors[] =
+      {
+          "none",
+          "light",
+          "dark",
+          "green",
+          "blue",
+          "yellow",
+          "orange"};
+
+  index = dt_conf_get_int("themes/focused-module-border");
+
+  if (index > 0)
+  {
+    char *chunk = g_strdup_printf("chunk-%s-focused-module-border.css",
+                                  border_colors[index]);
+    _add_theme_import(&themecss, datadir, "themes", chunk);
+    g_free(chunk);
+  }
+
+  index = dt_conf_get_int("themes/expanded-module-border");
+
+  if (index > 0)
+  {
+    char *chunk = g_strdup_printf("chunk-%s-expanded-module-border.css",
+                                  border_colors[index]);
+    _add_theme_import(&themecss, datadir, "themes", chunk);
+    g_free(chunk);
+  }
+
   // load any OS specific themes tweak file to fix some platform specific issues
 
 #ifdef __APPLE__