1 files changed, 292 insertions, 0 deletions
diff --git a/toolkit/components/places/ExtensionSearchHandler.jsm b/toolkit/components/places/ExtensionSearchHandler.jsm
new file mode 100644
index 000000000..3eb699ca1
--- /dev/null
+++ b/toolkit/components/places/ExtensionSearchHandler.jsm
@@ -0,0 +1,292 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+this.EXPORTED_SYMBOLS = [ "ExtensionSearchHandler" ];
+
+// Used to keep track of all of the registered keywords, where each keyword is
+// mapped to a KeywordInfo instance.
+let gKeywordMap = new Map();
+
+// Used to keep track of the active input session.
+let gActiveInputSession = null;
+
+// Used to keep track of who has control over the active suggestion callback
+// so older callbacks can be ignored. The callback ID should increment whenever
+// the input changes or the input session ends.
+let gCurrentCallbackID = 0;
+
+// Handles keeping track of information associated to the registered keyword.
+class KeywordInfo {
+  constructor(extension, description) {
+    this._extension = extension;
+    this._description = description;
+  }
+
+  get description() {
+    return this._description;
+  }
+
+  set description(desc) {
+    this._description = desc;
+  }
+
+  get extension() {
+    return this._extension;
+  }
+}
+
+// Responsible for handling communication between the extension and the urlbar.
+class InputSession {
+  constructor(keyword, extension) {
+    this._keyword = keyword;
+    this._extension = extension;
+    this._suggestionsCallback = null;
+    this._searchFinishedCallback = null;
+  }
+
+  get keyword() {
+    return this._keyword;
+  }
+
+  addSuggestions(suggestions) {
+    this._suggestionsCallback(suggestions);
+  }
+
+  start(eventName) {
+    this._extension.emit(eventName);
+  }
+
+  update(eventName, text, suggestionsCallback, searchFinishedCallback) {
+    if (this._searchFinishedCallback) {
+      this._searchFinishedCallback();
+    }
+    this._searchFinishedCallback = searchFinishedCallback;
+    this._suggestionsCallback = suggestionsCallback;
+    this._extension.emit(eventName, text, ++gCurrentCallbackID);
+  }
+
+  cancel(eventName) {
+    this._searchFinishedCallback();
+    this._extension.emit(eventName);
+  }
+
+  end(eventName, text, disposition) {
+    this._searchFinishedCallback();
+    this._extension.emit(eventName, text, disposition);
+  }
+}
+
+var ExtensionSearchHandler = Object.freeze({
+  MSG_INPUT_STARTED: "webext-omnibox-input-started",
+  MSG_INPUT_CHANGED: "webext-omnibox-input-changed",
+  MSG_INPUT_ENTERED: "webext-omnibox-input-entered",
+  MSG_INPUT_CANCELLED: "webext-omnibox-input-cancelled",
+
+  /**
+   * Registers a keyword.
+   *
+   * @param {string} keyword The keyword to register.
+   * @param {Extension} extension The extension registering the keyword.
+   */
+  registerKeyword(keyword, extension) {
+    if (gKeywordMap.has(keyword)) {
+      throw new Error(`The keyword provided is already registered: "${keyword}"`);
+    }
+    gKeywordMap.set(keyword, new KeywordInfo(extension, extension.name));
+  },
+
+  /**
+   * Unregisters a keyword.
+   *
+   * @param {string} keyword The keyword to unregister.
+   */
+  unregisterKeyword(keyword) {
+    if (!gKeywordMap.has(keyword)) {
+      throw new Error(`The keyword provided is not registered: "${keyword}"`);
+    }
+    gActiveInputSession = null;
+    gKeywordMap.delete(keyword);
+  },
+
+  /**
+   * Checks if a keyword is registered.
+   *
+   * @param {string} keyword The word to check.
+   * @return {boolean} true if the word is a registered keyword.
+   */
+  isKeywordRegistered(keyword) {
+    return gKeywordMap.has(keyword);
+  },
+
+  /**
+   * @return {boolean} true if there is an active input session.
+   */
+  hasActiveInputSession() {
+    return gActiveInputSession != null;
+  },
+
+  /**
+   * @param {string} keyword The keyword to look up.
+   * @return {string} the description to use for the heuristic result.
+   */
+  getDescription(keyword) {
+    if (!gKeywordMap.has(keyword)) {
+      throw new Error(`The keyword provided is not registered: "${keyword}"`);
+    }
+    return gKeywordMap.get(keyword).description;
+  },
+
+  /**
+   * Sets the default suggestion for the registered keyword. The suggestion's
+   * description will be used for the comment in the heuristic result.
+   *
+   * @param {string} keyword The keyword.
+   * @param {string} description The description to use for the heuristic result.
+   */
+  setDefaultSuggestion(keyword, {description}) {
+    if (!gKeywordMap.has(keyword)) {
+      throw new Error(`The keyword provided is not registered: "${keyword}"`);
+    }
+    gKeywordMap.get(keyword).description = description;
+  },
+
+  /**
+   * Adds suggestions for the registered keyword. This function will throw if
+   * the keyword provided is not registered or active, or if the callback ID
+   * provided is no longer equal to the active callback ID.
+   *
+   * @param {string} keyword The keyword.
+   * @param {integer} id The ID of the suggestion callback.
+   * @param {Array<Object>} suggestions An array of suggestions to provide to the urlbar.
+   */
+  addSuggestions(keyword, id, suggestions) {
+    if (!gKeywordMap.has(keyword)) {
+      throw new Error(`The keyword provided is not registered: "${keyword}"`);
+    }
+
+    if (!gActiveInputSession || gActiveInputSession.keyword != keyword) {
+      throw new Error(`The keyword provided is not apart of an active input session: "${keyword}"`);
+    }
+
+    if (id != gCurrentCallbackID) {
+      throw new Error(`The callback is no longer active for the keyword provided: "${keyword}"`);
+    }
+
+    gActiveInputSession.addSuggestions(suggestions);
+  },
+
+  /**
+   * Called when the input in the urlbar begins with `<keyword><space>`.
+   *
+   * If the keyword is inactive, MSG_INPUT_STARTED is emitted and the
+   * keyword is marked as active. If the keyword is followed by any text,
+   * MSG_INPUT_CHANGED is fired with the current callback ID that can be
+   * used to provide suggestions to the urlbar while the callback ID is active.
+   * The callback is invalidated when either the input changes or the urlbar blurs.
+   *
+   * @param {string} keyword The keyword to handle.
+   * @param {string} text The search text in the urlbar.
+   * @param {Function} callback The callback used to provide search suggestions.
+   * @return {Promise} promise that resolves when the current search is complete.
+   */
+  handleSearch(keyword, text, callback) {
+    if (!gKeywordMap.has(keyword)) {
+      throw new Error(`The keyword provided is not registered: "${keyword}"`);
+    }
+
+    if (gActiveInputSession && gActiveInputSession.keyword != keyword) {
+      throw new Error("A different input session is already ongoing");
+    }
+
+    if (!text || !text.startsWith(`${keyword} `)) {
+      throw new Error(`The text provided must start with: "${keyword} "`);
+    }
+
+    if (!callback) {
+      throw new Error("A callback must be provided");
+    }
+
+    // The search text in the urlbar currently starts with <keyword><space>, and
+    // we only want the text that follows.
+    text = text.substring(keyword.length + 1);
+
+    // We fire MSG_INPUT_STARTED once we have <keyword><space>, and only fire
+    // MSG_INPUT_CHANGED when we have text to process. This is different from Chrome's
+    // behavior, which always fires MSG_INPUT_STARTED right before MSG_INPUT_CHANGED
+    // first fires, but this is a bug in Chrome according to https://crbug.com/258911.
+    if (!gActiveInputSession) {
+      gActiveInputSession = new InputSession(keyword, gKeywordMap.get(keyword).extension);
+      gActiveInputSession.start(this.MSG_INPUT_STARTED);
+
+      // Resolve early if there is no text to process. There can be text to process when
+      // the input starts if the user copy/pastes the text into the urlbar.
+      if (!text.length) {
+        return Promise.resolve();
+      }
+    }
+
+    return new Promise(resolve => {
+      gActiveInputSession.update(this.MSG_INPUT_CHANGED, text, callback, resolve);
+    });
+  },
+
+  /**
+   * Called when the user clicks on a suggestion that was added by
+   * an extension. MSG_INPUT_ENTERED is emitted to the extension with
+   * the keyword, the current search string, and info about how the
+   * the search should be handled. This ends the active input session.
+   *
+   * @param {string} keyword The keyword associated to the suggestion.
+   * @param {string} text The search text in the urlbar.
+   * @param {string} where How the page should be opened. Accepted values are:
+   *    "current": open the page in the same tab.
+   *    "tab": open the page in a new foreground tab.
+   *    "tabshifted": open the page in a new background tab.
+   */
+  handleInputEntered(keyword, text, where) {
+    if (!gKeywordMap.has(keyword)) {
+      throw new Error(`The keyword provided is not registered: "${keyword}"`);
+    }
+
+    if (gActiveInputSession && gActiveInputSession.keyword != keyword) {
+      throw new Error("A different input session is already ongoing");
+    }
+
+    if (!text || !text.startsWith(`${keyword} `)) {
+      throw new Error(`The text provided must start with: "${keyword} "`);
+    }
+
+    let dispositionMap = {
+      current: "currentTab",
+      tab: "newForegroundTab",
+      tabshifted: "newBackgroundTab",
+    }
+    let disposition = dispositionMap[where];
+
+    if (!disposition) {
+      throw new Error(`Invalid "where" argument: ${where}`);
+    }
+
+    // The search text in the urlbar currently starts with <keyword><space>, and
+    // we only want to send the text that follows.
+    text = text.substring(keyword.length + 1);
+
+    gActiveInputSession.end(this.MSG_INPUT_ENTERED, text, disposition)
+    gActiveInputSession = null;
+  },
+
+  /**
+   * If the user has ended the keyword input session without accepting the input,
+   * MSG_INPUT_CANCELLED is emitted and the input session is ended.
+   */
+  handleInputCancelled() {
+    if (!gActiveInputSession) {
+      throw new Error("There is no active input session");
+    }
+    gActiveInputSession.cancel(this.MSG_INPUT_CANCELLED);
+    gActiveInputSession = null;
+  }
+});