wayland: implement xdg-activation

src/utils/threshold_counter.rs

@@ -0,0 +1,28 @@
+use crate::utils::numcell::NumCell;
+
+#[derive(Default)]
+pub struct ThresholdCounter {
+    counter: NumCell<usize>,
+}
+
+impl ThresholdCounter {
+    pub fn inc(&self) -> bool {
+        self.counter.fetch_add(1) == 0
+    }
+
+    pub fn dec(&self) -> bool {
+        self.counter.fetch_sub(1) == 1
+    }
+
+    pub fn adj(&self, inc: bool) -> bool {
+        if inc {
+            self.inc()
+        } else {
+            self.dec()
+        }
+    }
+
+    pub fn active(&self) -> bool {
+        self.counter.get() > 0
+    }
+}