1 files changed, 117 insertions, 0 deletions
diff --git a/remote/domains/parent/page/DialogHandler.jsm b/remote/domains/parent/page/DialogHandler.jsm
new file mode 100644
index 0000000000..26027a90db
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+++ b/remote/domains/parent/page/DialogHandler.jsm
@@ -0,0 +1,117 @@
+/* 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";
+
+var EXPORTED_SYMBOLS = ["DialogHandler"];
+
+const { EventEmitter } = ChromeUtils.import(
+  "resource://gre/modules/EventEmitter.jsm"
+);
+const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
+
+const DIALOG_TYPES = {
+  ALERT: "alert",
+  BEFOREUNLOAD: "beforeunload",
+  CONFIRM: "confirm",
+  PROMPT: "prompt",
+};
+
+/**
+ * Helper dedicated to detect and interact with browser dialogs such as `alert`,
+ * `confirm` etc. The current implementation only supports tabmodal dialogs,
+ * not full window dialogs.
+ *
+ * Emits "dialog-loaded" when a javascript dialog is opened for the current
+ * browser.
+ *
+ * @param {BrowserElement} browser
+ */
+class DialogHandler {
+  constructor(browser) {
+    EventEmitter.decorate(this);
+    this._dialog = null;
+    this._browser = browser;
+
+    this._onTabDialogLoaded = this._onTabDialogLoaded.bind(this);
+
+    Services.obs.addObserver(this._onTabDialogLoaded, "tabmodal-dialog-loaded");
+  }
+
+  destructor() {
+    this._dialog = null;
+    this._pageTarget = null;
+
+    Services.obs.removeObserver(
+      this._onTabDialogLoaded,
+      "tabmodal-dialog-loaded"
+    );
+  }
+
+  async handleJavaScriptDialog({ accept, promptText }) {
+    if (!this._dialog) {
+      throw new Error("No dialog available for handleJavaScriptDialog");
+    }
+
+    const type = this._getDialogType();
+    if (promptText && type === "prompt") {
+      this._dialog.ui.loginTextbox.value = promptText;
+    }
+
+    const onDialogClosed = new Promise(r => {
+      this._browser.addEventListener("DOMModalDialogClosed", r, {
+        once: true,
+      });
+    });
+
+    // 0 corresponds to the OK callback, 1 to the CANCEL callback.
+    if (accept) {
+      this._dialog.onButtonClick(0);
+    } else {
+      this._dialog.onButtonClick(1);
+    }
+
+    await onDialogClosed;
+
+    // Resetting dialog to null here might be racy and lead to errors if the
+    // content page is triggering several prompts in a row.
+    // See Bug 1569578.
+    this._dialog = null;
+  }
+
+  _getDialogType() {
+    const { inPermitUnload, promptType } = this._dialog.args;
+
+    if (inPermitUnload) {
+      return DIALOG_TYPES.BEFOREUNLOAD;
+    }
+
+    switch (promptType) {
+      case "alert":
+        return DIALOG_TYPES.ALERT;
+      case "confirm":
+        return DIALOG_TYPES.CONFIRM;
+      case "prompt":
+        return DIALOG_TYPES.PROMPT;
+      default:
+        throw new Error("Unsupported dialog type: " + promptType);
+    }
+  }
+
+  _onTabDialogLoaded(promptContainer) {
+    const prompts = this._browser.tabModalPromptBox.listPrompts();
+    const prompt = prompts.find(p => p.ui.promptContainer === promptContainer);
+
+    if (!prompt) {
+      // The dialog is not for the current tab.
+      return;
+    }
+
+    this._dialog = prompt;
+    const message = this._dialog.args.text;
+    const type = this._getDialogType();
+
+    this.emit("dialog-loaded", { message, type });
+  }
+}