shell: Allow triggering zoom

data/keybindings.ron

@@ -70,6 +70,9 @@
     (modifiers: [Super], key: "r"): Resizing(Outwards),
     (modifiers: [Super, Shift], key: "r"): Resizing(Inwards),
 
+    (modifiers: [Super], key: "equal"): ZoomIn,
+    (modifiers: [Super], key: "minus"): ZoomOut,
+
     (modifiers: [Super], key: "b"): System(WebBrowser),
     (modifiers: [Super], key: "f"): System(HomeFolder),
     (modifiers: [Super], key: "t"): System(Terminal),

src/input/actions.rs

@@ -1026,6 +1026,25 @@ impl State {
 
             Action::Spawn(command) => self.spawn_command(command),
 
+            x @ Action::ZoomIn | x @ Action::ZoomOut => {
+                let mut shell = self.common.shell.write().unwrap();
+                let pointer_loc = seat.get_pointer().unwrap().current_location().as_global();
+                let (zoom_seat, _, current_level) = shell
+                    .zoom_level()
+                    .unwrap_or_else(|| (seat.clone(), pointer_loc, 1.0));
+                if &zoom_seat == seat {
+                    shell.trigger_zoom(
+                        seat,
+                        pointer_loc,
+                        match x {
+                            Action::ZoomIn => current_level + 1.0,
+                            Action::ZoomOut => (current_level - 1.0).max(1.0),
+                            _ => unreachable!(),
+                        },
+                    );
+                }
+            }
+
             // Do nothing
             Action::Disable => (),
         }

src/shell/mod.rs

@@ -1966,6 +1966,24 @@ impl Shell {
         }
     }
 
+    pub fn trigger_zoom(
+        &mut self,
+        seat: &Seat<State>,
+        focal_point: Point<f64, Global>,
+        level: f64,
+    ) {
+        if level == 1. {
+            self.zoom_state.take();
+        } else {
+            self.zoom_state = Some(ZoomState {
+                seat: seat.clone(),
+                level,
+                focal_point,
+                previous: None,
+            });
+        }
+    }
+
     pub fn zoom_level(&self) -> Option<(Seat<State>, Point<f64, Global>, f64)> {
         self.zoom_state.as_ref().map(|s| s.level())
     }