8 files changed, 354 insertions, 177 deletions

diff --git a/src/content/MessageListener.ts b/src/content/MessageListener.ts
index 1d7a479..e545cab 100644
--- a/src/content/MessageListener.ts
+++ b/src/content/MessageListener.ts
@@ -1,14 +1,16 @@
 import { Message, valueOf } from '../shared/messages';
 
-export type WebMessageSender = Window | MessagePort | ServiceWorker | null;
 export type WebExtMessageSender = browser.runtime.MessageSender;
 
 export default class MessageListener {
   onWebMessage(
-    listener: (msg: Message, sender: WebMessageSender) => void,
+    listener: (msg: Message, sender: Window) => void,
   ) {
     window.addEventListener('message', (event: MessageEvent) => {
       let sender = event.source;
+      if (!(sender instanceof Window)) {
+        return;
+      }
       let message = null;
       try {
         message = JSON.parse(event.data);
diff --git a/src/content/actions/operation.ts b/src/content/actions/operation.ts
index 28192d7..657cf47 100644
--- a/src/content/actions/operation.ts
+++ b/src/content/actions/operation.ts
@@ -9,11 +9,13 @@ import AddonEnabledUseCase from '../usecases/AddonEnabledUseCase';
 import ClipboardUseCase from '../usecases/ClipboardUseCase';
 import { SettingRepositoryImpl } from '../repositories/SettingRepository';
 import { ScrollPresenterImpl } from '../presenters/ScrollPresenter';
+import { FollowMasterClientImpl } from '../client/FollowMasterClient';
 
 let addonEnabledUseCase = new AddonEnabledUseCase();
 let clipbaordUseCase = new ClipboardUseCase();
 let settingRepository = new SettingRepositoryImpl();
 let scrollPresenter = new ScrollPresenterImpl();
+let followMasterClient = new FollowMasterClientImpl(window.top);
 
 // eslint-disable-next-line complexity, max-lines-per-function
 const exec = async(
@@ -63,11 +65,7 @@ const exec = async(
     scrollPresenter.scrollToEnd(smoothscroll);
     break;
   case operations.FOLLOW_START:
-    window.top.postMessage(JSON.stringify({
-      type: messages.FOLLOW_START,
-      newTab: operation.newTab,
-      background: operation.background,
-    }), '*');
+    followMasterClient.startFollow(operation.newTab, operation.background);
     break;
   case operations.MARK_SET_PREFIX:
     return markActions.startSet();
diff --git a/src/content/client/FollowMasterClient.ts b/src/content/client/FollowMasterClient.ts
new file mode 100644
index 0000000..464b52f
--- /dev/null
+++ b/src/content/client/FollowMasterClient.ts
@@ -0,0 +1,47 @@
+import * as messages from '../../shared/messages';
+import { Key } from '../../shared/utils/keys';
+
+export default interface FollowMasterClient {
+  startFollow(newTab: boolean, background: boolean): void;
+
+  responseHintCount(count: number): void;
+
+  sendKey(key: Key): void;
+
+  // eslint-disable-next-line semi
+}
+
+export class FollowMasterClientImpl implements FollowMasterClient {
+  private window: Window;
+
+  constructor(window: Window) {
+    this.window = window;
+  }
+
+  startFollow(newTab: boolean, background: boolean): void {
+    this.postMessage({
+      type: messages.FOLLOW_START,
+      newTab,
+      background,
+    });
+  }
+
+  responseHintCount(count: number): void {
+    this.postMessage({
+      type: messages.FOLLOW_RESPONSE_COUNT_TARGETS,
+      count,
+    });
+  }
+
+  sendKey(key: Key): void {
+    this.postMessage({
+      type: messages.FOLLOW_KEY_PRESS,
+      key: key.key,
+      ctrlKey: key.ctrlKey || false,
+    });
+  }
+
+  private postMessage(msg: messages.Message): void {
+    this.window.postMessage(JSON.stringify(msg), '*');
+  }
+}
diff --git a/src/content/client/FollowSlaveClient.ts b/src/content/client/FollowSlaveClient.ts
new file mode 100644
index 0000000..0905cd9
--- /dev/null
+++ b/src/content/client/FollowSlaveClient.ts
@@ -0,0 +1,76 @@
+import * as messages from '../../shared/messages';
+
+interface Size {
+  width: number;
+  height: number;
+}
+
+interface Point {
+  x: number;
+  y: number;
+}
+
+export default interface FollowSlaveClient {
+  filterHints(prefix: string): void;
+
+  requestHintCount(viewSize: Size, framePosition: Point): void;
+
+  createHints(viewSize: Size, framePosition: Point, tags: string[]): void;
+
+  clearHints(): void;
+
+  activateIfExists(tag: string, newTab: boolean, background: boolean): void;
+
+  // eslint-disable-next-line semi
+}
+
+export class FollowSlaveClientImpl implements FollowSlaveClient {
+  private target: Window;
+
+  constructor(target: Window) {
+    this.target = target;
+  }
+
+  filterHints(prefix: string): void {
+    this.postMessage({
+      type: messages.FOLLOW_SHOW_HINTS,
+      prefix,
+    });
+  }
+
+  requestHintCount(viewSize: Size, framePosition: Point): void {
+    this.postMessage({
+      type: messages.FOLLOW_REQUEST_COUNT_TARGETS,
+      viewSize,
+      framePosition,
+    });
+  }
+
+  createHints(viewSize: Size, framePosition: Point, tags: string[]): void {
+    this.postMessage({
+      type: messages.FOLLOW_CREATE_HINTS,
+      viewSize,
+      framePosition,
+      tags,
+    });
+  }
+
+  clearHints(): void {
+    this.postMessage({
+      type: messages.FOLLOW_REMOVE_HINTS,
+    });
+  }
+
+  activateIfExists(tag: string, newTab: boolean, background: boolean): void {
+    this.postMessage({
+      type: messages.FOLLOW_ACTIVATE,
+      tag,
+      newTab,
+      background,
+    });
+  }
+
+  private postMessage(msg: messages.Message): void {
+    this.target.postMessage(JSON.stringify(msg), '*');
+  }
+}
diff --git a/src/content/components/common/follow.ts b/src/content/components/common/follow.ts
index 9a62613..e0003e3 100644
--- a/src/content/components/common/follow.ts
+++ b/src/content/components/common/follow.ts
@@ -1,17 +1,18 @@
 import MessageListener from '../../MessageListener';
-import Hint, { LinkHint, InputHint } from '../../presenters/Hint';
-import * as dom from '../../../shared/utils/dom';
+import { LinkHint, InputHint } from '../../presenters/Hint';
 import * as messages from '../../../shared/messages';
-import * as keyUtils from '../../../shared/utils/keys';
+import { Key } from '../../../shared/utils/keys';
 import TabsClient, { TabsClientImpl } from '../../client/TabsClient';
+import FollowMasterClient, { FollowMasterClientImpl }
+  from '../../client/FollowMasterClient';
+import FollowPresenter, { FollowPresenterImpl }
+  from '../../presenters/FollowPresenter';
 
 let tabsClient: TabsClient = new TabsClientImpl();
-
-const TARGET_SELECTOR = [
-  'a', 'button', 'input', 'textarea', 'area',
-  '[contenteditable=true]', '[contenteditable=""]', '[tabindex]',
-  '[role="button"]', 'summary'
-].join(',');
+let followMasterClient: FollowMasterClient =
+  new FollowMasterClientImpl(window.top);
+let followPresenter: FollowPresenter =
+  new FollowPresenterImpl();
 
 interface Size {
   width: number;
@@ -23,118 +24,46 @@ interface Point {
   y: number;
 }
 
-const inViewport = (
-  win: Window,
-  element: Element,
-  viewSize: Size,
-  framePosition: Point,
-): boolean => {
-  let {
-    top, left, bottom, right
-  } = dom.viewportRect(element);
-  let doc = win.document;
-  let frameWidth = doc.documentElement.clientWidth;
-  let frameHeight = doc.documentElement.clientHeight;
-
-  if (right < 0 || bottom < 0 || top > frameHeight || left > frameWidth) {
-    // out of frame
-    return false;
-  }
-  if (right + framePosition.x < 0 || bottom + framePosition.y < 0 ||
-      left + framePosition.x > viewSize.width ||
-      top + framePosition.y > viewSize.height) {
-    // out of viewport
-    return false;
-  }
-  return true;
-};
-
-const isAriaHiddenOrAriaDisabled = (win: Window, element: Element): boolean => {
-  if (!element || win.document.documentElement === element) {
-    return false;
-  }
-  for (let attr of ['aria-hidden', 'aria-disabled']) {
-    let value = element.getAttribute(attr);
-    if (value !== null) {
-      let hidden = value.toLowerCase();
-      if (hidden === '' || hidden === 'true') {
-        return true;
-      }
-    }
-  }
-  return isAriaHiddenOrAriaDisabled(win, element.parentElement as Element);
-};
-
 export default class Follow {
-  private win: Window;
+  private enabled: boolean;
 
-  private hints: {[key: string]: Hint };
-
-  private targets: HTMLElement[] = [];
-
-  constructor(win: Window) {
-    this.win = win;
-    this.hints = {};
-    this.targets = [];
+  constructor() {
+    this.enabled = false;
 
     new MessageListener().onWebMessage(this.onMessage.bind(this));
   }
 
-  key(key: keyUtils.Key): boolean {
-    if (Object.keys(this.hints).length === 0) {
+  key(key: Key): boolean {
+    if (!this.enabled) {
       return false;
     }
-    this.win.parent.postMessage(JSON.stringify({
-      type: messages.FOLLOW_KEY_PRESS,
-      key: key.key,
-      ctrlKey: key.ctrlKey,
-    }), '*');
+    followMasterClient.sendKey(key);
     return true;
   }
 
-  countHints(sender: any, viewSize: Size, framePosition: Point) {
-    this.targets = Follow.getTargetElements(this.win, viewSize, framePosition);
-    sender.postMessage(JSON.stringify({
-      type: messages.FOLLOW_RESPONSE_COUNT_TARGETS,
-      count: this.targets.length,
-    }), '*');
+  countHints(viewSize: Size, framePosition: Point) {
+    let count = followPresenter.getTargetCount(viewSize, framePosition);
+    followMasterClient.responseHintCount(count);
   }
 
-  createHints(keysArray: string[]) {
-    if (keysArray.length !== this.targets.length) {
-      throw new Error('illegal hint count');
-    }
-
-    this.hints = {};
-    for (let i = 0; i < keysArray.length; ++i) {
-      let keys = keysArray[i];
-      let target = this.targets[i];
-      if (target instanceof HTMLAnchorElement ||
-        target instanceof HTMLAreaElement) {
-        this.hints[keys] = new LinkHint(target, keys);
-      } else {
-        this.hints[keys] = new InputHint(target, keys);
-      }
-    }
+  createHints(viewSize: Size, framePosition: Point, tags: string[]) {
+    this.enabled = true;
+    followPresenter.createHints(viewSize, framePosition, tags);
   }
 
-  showHints(keys: string) {
-    Object.keys(this.hints).filter(key => key.startsWith(keys))
-      .forEach(key => this.hints[key].show());
-    Object.keys(this.hints).filter(key => !key.startsWith(keys))
-      .forEach(key => this.hints[key].hide());
+  showHints(prefix: string) {
+    followPresenter.filterHints(prefix);
   }
 
   removeHints() {
-    Object.keys(this.hints).forEach((key) => {
-      this.hints[key].remove();
-    });
-    this.hints = {};
-    this.targets = [];
+    followPresenter.clearHints();
+    this.enabled = false;
   }
 
-  async activateHints(keys: string, newTab: boolean, background: boolean): Promise<void> {
-    let hint = this.hints[keys];
+  async activateHints(
+    tag: string, newTab: boolean, background: boolean,
+  ): Promise<void> {
+    let hint = followPresenter.getHint(tag);
     if (!hint) {
       return;
     }
@@ -156,38 +85,20 @@ export default class Follow {
     }
   }
 
-  onMessage(message: messages.Message, sender: any) {
+  onMessage(message: messages.Message, _sender: Window) {
     switch (message.type) {
     case messages.FOLLOW_REQUEST_COUNT_TARGETS:
-      return this.countHints(sender, message.viewSize, message.framePosition);
+      return this.countHints(message.viewSize, message.framePosition);
     case messages.FOLLOW_CREATE_HINTS:
-      return this.createHints(message.keysArray);
+      return this.createHints(
+        message.viewSize, message.framePosition, message.tags);
     case messages.FOLLOW_SHOW_HINTS:
-      return this.showHints(message.keys);
+      return this.showHints(message.prefix);
     case messages.FOLLOW_ACTIVATE:
-      return this.activateHints(message.keys, message.newTab, message.background);
+      return this.activateHints(
+        message.tag, message.newTab, message.background);
     case messages.FOLLOW_REMOVE_HINTS:
       return this.removeHints();
     }
   }
-
-  static getTargetElements(
-    win: Window,
-    viewSize:
-    Size, framePosition: Point,
-  ): HTMLElement[] {
-    let all = win.document.querySelectorAll(TARGET_SELECTOR);
-    let filtered = Array.prototype.filter.call(all, (element: HTMLElement) => {
-      let style = win.getComputedStyle(element);
-
-      // AREA's 'display' in Browser style is 'none'
-      return (element.tagName === 'AREA' || style.display !== 'none') &&
-        style.visibility !== 'hidden' &&
-        (element as HTMLInputElement).type !== 'hidden' &&
-        element.offsetHeight > 0 &&
-        !isAriaHiddenOrAriaDisabled(win, element) &&
-        inViewport(win, element, viewSize, framePosition);
-    });
-    return filtered;
-  }
 }
diff --git a/src/content/components/common/index.ts b/src/content/components/common/index.ts
index 899953d..b2f48a3 100644
--- a/src/content/components/common/index.ts
+++ b/src/content/components/common/index.ts
@@ -16,7 +16,7 @@ let settingUseCase = new SettingUseCase();
 export default class Common {
   constructor(win: Window, store: any) {
     const input = new InputComponent(win.document.body);
-    const follow = new FollowComponent(win);
+    const follow = new FollowComponent();
     const mark = new MarkComponent(store);
     const keymapper = new KeymapperComponent(store);
 
diff --git a/src/content/components/top-content/follow-controller.ts b/src/content/components/top-content/follow-controller.ts
index 2a242c2..43c917e 100644
--- a/src/content/components/top-content/follow-controller.ts
+++ b/src/content/components/top-content/follow-controller.ts
@@ -1,18 +1,14 @@
 import * as followControllerActions from '../../actions/follow-controller';
 import * as messages from '../../../shared/messages';
-import MessageListener, { WebMessageSender } from '../../MessageListener';
+import MessageListener from '../../MessageListener';
 import HintKeyProducer from '../../hint-key-producer';
 
 import { SettingRepositoryImpl } from '../../repositories/SettingRepository';
+import FollowSlaveClient, { FollowSlaveClientImpl }
+  from '../../client/FollowSlaveClient';
 
 let settingRepository = new SettingRepositoryImpl();
 
-const broadcastMessage = (win: Window, message: messages.Message): void => {
-  let json = JSON.stringify(message);
-  let frames = [win.self].concat(Array.from(win.frames as any));
-  frames.forEach(frame => frame.postMessage(json, '*'));
-};
-
 export default class FollowController {
   private win: Window;
 
@@ -43,7 +39,7 @@ export default class FollowController {
     });
   }
 
-  onMessage(message: messages.Message, sender: WebMessageSender) {
+  onMessage(message: messages.Message, sender: Window) {
     switch (message.type) {
     case messages.FOLLOW_START:
       return this.store.dispatch(
@@ -77,18 +73,17 @@ export default class FollowController {
       this.store.dispatch(followControllerActions.disable());
     }
 
-    broadcastMessage(this.win, {
-      type: messages.FOLLOW_SHOW_HINTS,
-      keys: this.state.keys as string,
+    this.broadcastMessage((c: FollowSlaveClient) => {
+      c.filterHints(this.state.keys!!);
     });
   }
 
   activate(): void {
-    broadcastMessage(this.win, {
-      type: messages.FOLLOW_ACTIVATE,
-      keys: this.state.keys as string,
-      newTab: this.state.newTab!!,
-      background: this.state.background!!,
+    this.broadcastMessage((c: FollowSlaveClient) => {
+      c.activateIfExists(
+        this.state.keys!!,
+        this.state.newTab!!,
+        this.state.background!!);
     });
   }
 
@@ -123,50 +118,64 @@ export default class FollowController {
     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((ele) => {
+    let frameElements = this.win.document.querySelectorAll('iframe');
+
+    new FollowSlaveClientImpl(this.win).requestHintCount(
+      { width: viewWidth, height: viewHeight },
+      { x: 0, y: 0 });
+
+    for (let ele of Array.from(frameElements)) {
       let { left: frameX, top: frameY } = ele.getBoundingClientRect();
-      let message = JSON.stringify({
-        type: messages.FOLLOW_REQUEST_COUNT_TARGETS,
-        viewSize: { width: viewWidth, height: viewHeight },
-        framePosition: { x: frameX, y: frameY },
-      });
-      if (ele instanceof HTMLFrameElement && ele.contentWindow ||
-        ele instanceof HTMLIFrameElement && ele.contentWindow) {
-        ele.contentWindow.postMessage(message, '*');
-      }
-    });
+      new FollowSlaveClientImpl(ele.contentWindow!!).requestHintCount(
+        { width: viewWidth, height: viewHeight },
+        { x: frameX, y: frameY },
+      );
+    }
   }
 
-  create(count: number, sender: WebMessageSender) {
+  create(count: number, sender: Window) {
     let produced = [];
     for (let i = 0; i < count; ++i) {
       produced.push((this.producer as HintKeyProducer).produce());
     }
     this.keys = this.keys.concat(produced);
 
-    (sender as Window).postMessage(JSON.stringify({
-      type: messages.FOLLOW_CREATE_HINTS,
-      keysArray: produced,
-      newTab: this.state.newTab,
-      background: this.state.background,
-    }), '*');
+    let doc = this.win.document;
+    let viewWidth = this.win.innerWidth || doc.documentElement.clientWidth;
+    let viewHeight = this.win.innerHeight || doc.documentElement.clientHeight;
+    let pos = { x: 0, y: 0 };
+    if (sender !== window) {
+      let frameElements = this.win.document.querySelectorAll('iframe');
+      let ele = Array.from(frameElements).find(e => e.contentWindow === sender);
+      if (!ele) {
+        // elements of the sender is gone
+        return;
+      }
+      let { left: frameX, top: frameY } = ele.getBoundingClientRect();
+      pos = { x: frameX, y: frameY };
+    }
+    new FollowSlaveClientImpl(sender).createHints(
+      { width: viewWidth, height: viewHeight },
+      pos,
+      produced,
+    );
   }
 
   remove() {
     this.keys = [];
-    broadcastMessage(this.win, {
-      type: messages.FOLLOW_REMOVE_HINTS,
+    this.broadcastMessage((c: FollowSlaveClient) => {
+      c.clearHints();
     });
   }
 
   private hintchars() {
     return settingRepository.get().properties.hintchars;
   }
+
+  private broadcastMessage(f: (clinet: FollowSlaveClient) => void) {
+    let windows = [window.self].concat(Array.from(window.frames as any));
+    windows
+      .map(w => new FollowSlaveClientImpl(w))
+      .forEach(c => f(c));
+  }
 }
diff --git a/src/content/presenters/FollowPresenter.ts b/src/content/presenters/FollowPresenter.ts
new file mode 100644
index 0000000..f0d115c
--- /dev/null
+++ b/src/content/presenters/FollowPresenter.ts
@@ -0,0 +1,134 @@
+import Hint, { InputHint, LinkHint } from './Hint';
+import * as doms from '../../shared/utils/dom';
+
+const TARGET_SELECTOR = [
+  'a', 'button', 'input', 'textarea', 'area',
+  '[contenteditable=true]', '[contenteditable=""]', '[tabindex]',
+  '[role="button"]', 'summary'
+].join(',');
+
+interface Size {
+  width: number;
+  height: number;
+}
+
+interface Point {
+  x: number;
+  y: number;
+}
+
+const inViewport = (
+  win: Window,
+  element: Element,
+  viewSize: Size,
+  framePosition: Point,
+): boolean => {
+  let {
+    top, left, bottom, right
+  } = doms.viewportRect(element);
+  let doc = win.document;
+  let frameWidth = doc.documentElement.clientWidth;
+  let frameHeight = doc.documentElement.clientHeight;
+
+  if (right < 0 || bottom < 0 || top > frameHeight || left > frameWidth) {
+    // out of frame
+    return false;
+  }
+  if (right + framePosition.x < 0 || bottom + framePosition.y < 0 ||
+      left + framePosition.x > viewSize.width ||
+      top + framePosition.y > viewSize.height) {
+    // out of viewport
+    return false;
+  }
+  return true;
+};
+
+const isAriaHiddenOrAriaDisabled = (win: Window, element: Element): boolean => {
+  if (!element || win.document.documentElement === element) {
+    return false;
+  }
+  for (let attr of ['aria-hidden', 'aria-disabled']) {
+    let value = element.getAttribute(attr);
+    if (value !== null) {
+      let hidden = value.toLowerCase();
+      if (hidden === '' || hidden === 'true') {
+        return true;
+      }
+    }
+  }
+  return isAriaHiddenOrAriaDisabled(win, element.parentElement as Element);
+};
+
+export default interface FollowPresenter {
+  getTargetCount(viewSize: Size, framePosition: Point): number;
+
+  createHints(viewSize: Size, framePosition: Point, tags: string[]): void;
+
+  filterHints(prefix: string): void;
+
+  clearHints(): void;
+
+  getHint(tag: string): Hint | undefined;
+
+  // eslint-disable-next-line semi
+}
+
+export class FollowPresenterImpl implements FollowPresenter {
+  private hints: Hint[]
+
+  constructor() {
+    this.hints = [];
+  }
+
+  getTargetCount(viewSize: Size, framePosition: Point): number {
+    let targets = this.getTargets(viewSize, framePosition);
+    return targets.length;
+  }
+
+  createHints(viewSize: Size, framePosition: Point, tags: string[]): void {
+    let targets = this.getTargets(viewSize, framePosition);
+    let min = Math.min(targets.length, tags.length);
+    for (let i = 0; i < min; ++i) {
+      let target = targets[i];
+      if (target instanceof HTMLAnchorElement ||
+        target instanceof HTMLAreaElement) {
+        this.hints.push(new LinkHint(target, tags[i]));
+      } else {
+        this.hints.push(new InputHint(target, tags[i]));
+      }
+    }
+  }
+
+  filterHints(prefix: string): void {
+    let shown = this.hints.filter(h => h.getTag().startsWith(prefix));
+    let hidden = this.hints.filter(h => !h.getTag().startsWith(prefix));
+
+    shown.forEach(h => h.show());
+    hidden.forEach(h => h.hide());
+  }
+
+  clearHints(): void {
+    this.hints.forEach(h => h.remove());
+    this.hints = [];
+  }
+
+  getHint(tag: string): Hint | undefined {
+    return this.hints.find(h => h.getTag() === tag);
+  }
+
+  private getTargets(viewSize: Size, framePosition: Point): HTMLElement[] {
+    let all = window.document.querySelectorAll(TARGET_SELECTOR);
+    let filtered = Array.prototype.filter.call(all, (element: HTMLElement) => {
+      let style = window.getComputedStyle(element);
+
+      // AREA's 'display' in Browser style is 'none'
+      return (element.tagName === 'AREA' || style.display !== 'none') &&
+        style.visibility !== 'hidden' &&
+        (element as HTMLInputElement).type !== 'hidden' &&
+        element.offsetHeight > 0 &&
+        !isAriaHiddenOrAriaDisabled(window, element) &&
+        inViewport(window, element, viewSize, framePosition);
+    });
+    return filtered;
+  }
+}