feat: basic keyboard shortcuts (#319)

composables/magickeys.ts

@@ -0,0 +1,44 @@
+import type { ComputedRef } from 'vue'
+
+// TODO: consider to allow combinations similar to useMagicKeys using proxy?
+//       e.g. `const magicSequence = useMagicSequence()`
+//         `magicSequence['Shift+Ctrl+A']`
+//         `const { Ctrl_A_B } = useMagicSequence()`
+
+/**
+ * source: inspired by https://github.com/vueuse/vueuse/issues/427#issuecomment-815619446
+ * @param keys ordered list of keys making up the sequence
+ */
+export function useMagicSequence(keys: string[]): ComputedRef<boolean> {
+  const magicKeys = useMagicKeys()
+
+  const success = ref(false)
+  const i = ref(0)
+  let down = false
+
+  watch(
+    () => magicKeys.current,
+    () => {
+      if (magicKeys[keys[i.value]].value && !down) {
+        down = true
+        i.value += 1
+      }
+      else if (i.value > 0 && !magicKeys[keys[i.value - 1]].value && down) {
+        down = false
+      }
+      else {
+        i.value = 0
+        down = false
+        success.value = false
+      }
+      if (i.value >= keys.length && !down) {
+        i.value = 0
+        down = false
+        success.value = true
+      }
+    }, {
+      deep: true,
+    })
+
+  return computed(() => success.value)
+}