1 files changed, 131 insertions, 0 deletions
diff --git a/src/content/components/top-content/follow-controller.js b/src/content/components/top-content/follow-controller.js
new file mode 100644
index 0000000..29f40b3
--- /dev/null
+++ b/src/content/components/top-content/follow-controller.js
@@ -0,0 +1,131 @@
+import * as followActions from 'content/actions/follow';
+import messages from 'shared/messages';
+import HintKeyProducer from 'content/hint-key-producer';
+
+const DEFAULT_HINT_CHARSET = 'abcdefghijklmnopqrstuvwxyz';
+
+const broadcastMessage = (win, message) => {
+  let json = JSON.stringify(message);
+  let frames = [window.self].concat(Array.from(window.frames));
+  frames.forEach(frame => frame.postMessage(json, '*'));
+};
+
+export default class FollowController {
+  constructor(win, store) {
+    this.win = win;
+    this.store = store;
+    this.state = {};
+    this.keys = [];
+    this.producer = null;
+  }
+
+  onMessage(message, sender) {
+    switch (message.type) {
+    case messages.FOLLOW_START:
+      return this.store.dispatch(followActions.enable(message.newTab));
+    case messages.FOLLOW_RESPONSE_COUNT_TARGETS:
+      return this.create(message.count, sender);
+    case messages.FOLLOW_KEY_PRESS:
+      return this.keyPress(message.key);
+    }
+  }
+
+  update() {
+    let prevState = this.state;
+    this.state = this.store.getState().follow;
+
+    if (!prevState.enabled && this.state.enabled) {
+      this.count();
+    } else if (prevState.enabled && !this.state.enabled) {
+      this.remove();
+    } else if (prevState.keys !== this.state.keys) {
+      this.updateHints();
+    }
+  }
+
+  updateHints() {
+    let shown = this.keys.filter(key => key.startsWith(this.state.keys));
+    if (shown.length === 1) {
+      this.activate();
+      this.store.dispatch(followActions.disable());
+    }
+
+    broadcastMessage(this.win, {
+      type: messages.FOLLOW_SHOW_HINTS,
+      keys: this.state.keys,
+    });
+  }
+
+  activate() {
+    broadcastMessage(this.win, {
+      type: messages.FOLLOW_ACTIVATE,
+      keys: this.state.keys,
+    });
+  }
+
+  keyPress(key) {
+    switch (key) {
+    case 'Enter':
+      this.activate();
+      this.store.dispatch(followActions.disable());
+      break;
+    case 'Escape':
+      this.store.dispatch(followActions.disable());
+      break;
+    case 'Backspace':
+    case 'Delete':
+      this.store.dispatch(followActions.backspace());
+      break;
+    default:
+      if (DEFAULT_HINT_CHARSET.includes(key)) {
+        this.store.dispatch(followActions.keyPress(key));
+      }
+      break;
+    }
+    return true;
+  }
+
+  count() {
+    this.producer = new HintKeyProducer(DEFAULT_HINT_CHARSET);
+    let doc = this.win.document;
+    let viewWidth = this.win.innerWidth || doc.documentElement.clientWidth;
+    let viewHeight = this.win.innerHeight || doc.documentElement.clientHeight;
+    let frameElements = this.win.document.querySelectorAll('frame,iframe');
+
+    this.win.postMessage(JSON.stringify({
+      type: messages.FOLLOW_REQUEST_COUNT_TARGETS,
+      viewSize: { width: viewWidth, height: viewHeight },
+      framePosition: { x: 0, y: 0 },
+    }), '*');
+    frameElements.forEach((element) => {
+      let { left: frameX, top: frameY } = element.getBoundingClientRect();
+      let message = JSON.stringify({
+        type: messages.FOLLOW_REQUEST_COUNT_TARGETS,
+        viewSize: { width: viewWidth, height: viewHeight },
+        framePosition: { x: frameX, y: frameY },
+      });
+      element.contentWindow.postMessage(message, '*');
+    });
+  }
+
+  create(count, sender) {
+    let produced = [];
+    for (let i = 0; i < count; ++i) {
+      produced.push(this.producer.produce());
+    }
+    this.keys = this.keys.concat(produced);
+
+    sender.postMessage(JSON.stringify({
+      type: messages.FOLLOW_CREATE_HINTS,
+      keysArray: produced,
+      newTab: this.state.newTab,
+    }), '*');
+  }
+
+  remove() {
+    this.keys = [];
+    broadcastMessage(this.win, {
+      type: messages.FOLLOW_REMOVE_HINTS,
+    });
+  }
+}