add gravity property to label widget (#949)

CHANGELOG.md

@@ -12,6 +12,7 @@ All notable changes to eww will be listed here, starting at changes since versio
 - Add `:namespace` window option
 - Default to building with x11 and wayland support simultaneously
 - Add `truncate-left` property on `label` widgets (By: kawaki-san)
+- Add `gravity` property on `label` widgets (By: Elekrisk)
 - Add support for safe access (`?.`) in simplexpr (By: oldwomanjosiah)
 - Allow floating-point numbers in percentages for window-geometry
 - Add support for safe access with index (`?.[n]`) (By: ModProg)

crates/eww/src/widgets/widget_definitions.rs

@@ -861,6 +861,10 @@ fn build_gtk_label(bargs: &mut BuilderArgs) -> Result<gtk::Label> {
         prop(wrap: as_bool) { gtk_widget.set_line_wrap(wrap) },
         // @prop angle - the angle of rotation for the label (between 0 - 360)
         prop(angle: as_f64 = 0) { gtk_widget.set_angle(angle) },
+        // @prop gravity - the gravity of the string (south, east, west, north, auto). Text will want to face the direction of gravity.
+        prop(gravity: as_string = "south") {
+            gtk_widget.pango_context().set_base_gravity(parse_gravity(&gravity)?);
+        },
         // @prop xalign - the alignment of the label text on the x axis (between 0 - 1, 0 -> left, 0.5 -> center, 1 -> right)
         prop(xalign: as_f64 = 0.5) { gtk_widget.set_xalign(xalign as f32) },
         // @prop yalign - the alignment of the label text on the y axis (between 0 - 1, 0 -> bottom, 0.5 -> center, 1 -> top)
@@ -1148,6 +1152,17 @@ fn parse_justification(j: &str) -> Result<gtk::Justification> {
     }
 }
 
+/// @var gravity - "south", "east", "west", "north", "auto"
+fn parse_gravity(g: &str) -> Result<gtk::pango::Gravity> {
+    enum_parse! { "gravity", g,
+        "south" => gtk::pango::Gravity::South,
+        "east" => gtk::pango::Gravity::East,
+        "west" => gtk::pango::Gravity::West,
+        "north" => gtk::pango::Gravity::North,
+        "auto" => gtk::pango::Gravity::Auto,
+    }
+}
+
 /// Connect a function to the first map event of a widget. After that first map, the handler will get disconnected.
 fn connect_first_map<W: IsA<gtk::Widget>, F: Fn(&W) + 'static>(widget: &W, func: F) {
     let signal_handler_id = std::rc::Rc::new(std::cell::RefCell::new(None));