Bug 1588420 - Add init() to SharePicker.idl, which provides a means to get to browser parent r=droeh

Differential Revision: https://phabricator.services.mozilla.com/D49215

--HG--
extra : moz-landing-system : lando

browser/components/webshare/SharePicker.js

@@ -7,7 +7,9 @@ const { XPCOMUtils } = ChromeUtils.import(
 );
 
 class SharePicker {
-  constructor() {}
+  constructor() {
+    this._initialized = false;
+  }
 
   get classDescription() {
     return "Web Share Picker";
@@ -25,6 +27,25 @@ class SharePicker {
     return ChromeUtils.generateQI([Ci.nsISharePicker]);
   }
 
+  /**
+   * Initializer.
+   *
+   * @param {nsIDOMWindow} openerWindow
+   */
+  init(openerWindow) {
+    if (this._initialized) {
+      throw new Error("Unexpected re-initialization. This is not allowed.");
+    }
+
+    this._initialized = true;
+
+    if (openerWindow instanceof Ci.nsIDOMWindow === false) {
+      throw new TypeError("Expected nsIDOMWindow");
+    }
+
+    this._openerWindow = openerWindow;
+  }
+
   /**
    * The data being shared by the Document.
    *
@@ -49,6 +70,12 @@ class SharePicker {
     throw new DOMException("Not supported.", "AbortError");
   }
 
+  /**
+   * @returns mozIDOMWindowProxy
+   */
+  get openerWindow() {
+    return this._openerWindow;
+  }
   __init() {}
 }
 

dom/ipc/WindowGlobalParent.cpp

@@ -357,12 +357,24 @@ mozilla::ipc::IPCResult WindowGlobalParent::RecvShare(
   // Widget Layer handoff...
   nsCOMPtr<nsISharePicker> sharePicker =
       do_GetService("@mozilla.org/sharepicker;1");
-
   if (!sharePicker) {
     aResolver(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
     return IPC_OK();
   }
 
+  // Initialize the ShareWidget
+  RefPtr<BrowserParent> parent = GetBrowserParent();
+  if (NS_WARN_IF(!parent)) {
+    aResolver(NS_ERROR_FAILURE);
+    return IPC_OK();
+  }
+  nsCOMPtr<mozIDOMWindowProxy> openerWindow = parent->GetParentWindowOuter();
+  if (!openerWindow) {
+    aResolver(NS_ERROR_FAILURE);
+    return IPC_OK();
+  }
+  sharePicker->Init(openerWindow);
+
   // And finally share the data...
   RefPtr<Promise> promise;
   nsresult rv = sharePicker->Share(aData.title(), aData.text(), aData.url(),

widget/nsISharePicker.idl

@@ -8,9 +8,22 @@
 
 interface nsIURI;
 
+interface mozIDOMWindowProxy;
+
 [scriptable, uuid(1201d357-8417-4926-a694-e6408fbedcf8)]
 interface nsISharePicker : nsISupports
 {
+  /**
+   * Initialize the share picker widget.
+   * @param nsIDOMWindow openerWindow.
+   */
+  void init(in mozIDOMWindowProxy openerWindow);
+
+  /**
+   * Returns the parent window this was initialized with.
+   */
+  readonly attribute mozIDOMWindowProxy openerWindow;
+
   /**
    * XPCOM Analog of navigator.share() as per:
    * https://w3c.github.io/web-share/#share-method