1 files changed, 72 insertions, 0 deletions
diff --git a/src/content/components/common/input.js b/src/content/components/common/input.js
new file mode 100644
index 0000000..df09894
--- /dev/null
+++ b/src/content/components/common/input.js
@@ -0,0 +1,72 @@
+export default class InputComponent {
+  constructor(target) {
+    this.pressed = {};
+    this.onKeyListeners = [];
+
+    target.addEventListener('keypress', this.onKeyPress.bind(this));
+    target.addEventListener('keydown', this.onKeyDown.bind(this));
+    target.addEventListener('keyup', this.onKeyUp.bind(this));
+  }
+
+  update() {
+  }
+
+  onKey(cb) {
+    this.onKeyListeners.push(cb);
+  }
+
+  onKeyPress(e) {
+    if (this.pressed[e.key] && this.pressed[e.key] !== 'keypress') {
+      return;
+    }
+    this.pressed[e.key] = 'keypress';
+    this.capture(e);
+  }
+
+  onKeyDown(e) {
+    if (this.pressed[e.key] && this.pressed[e.key] !== 'keydown') {
+      return;
+    }
+    this.pressed[e.key] = 'keydown';
+    this.capture(e);
+  }
+
+  onKeyUp(e) {
+    delete this.pressed[e.key];
+  }
+
+  capture(e) {
+    if (this.fromInput(e)) {
+      if (e.key === 'Escape' && e.target.blur) {
+        e.target.blur();
+      }
+      return;
+    }
+    if (['Shift', 'Control', 'Alt', 'OS'].includes(e.key)) {
+      // pressing only meta key is ignored
+      return;
+    }
+
+    let stop = false;
+    for (let listener of this.onKeyListeners) {
+      stop = stop || listener(e.key, e.ctrlKey);
+      if (stop) {
+        break;
+      }
+    }
+    if (stop) {
+      e.preventDefault();
+      e.stopPropagation();
+    }
+  }
+
+  fromInput(e) {
+    return e.target instanceof HTMLInputElement ||
+      e.target instanceof HTMLTextAreaElement ||
+      e.target instanceof HTMLSelectElement ||
+      e.target instanceof HTMLElement &&
+      e.target.hasAttribute('contenteditable') && (
+          e.target.getAttribute('contenteditable').toLowerCase() === 'true' ||
+          e.target.getAttribute('contenteditable').toLowerCase() === '');
+  }
+}