Bug 1515285 - Implement selecting switch-to-tab results by keyboard. r=Standard8

Differential Revision: https://phabricator.services.mozilla.com/D16023

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

browser/components/urlbar/UrlbarInput.jsm

@@ -214,6 +214,16 @@ class UrlbarInput {
     //   return;
     // }
 
+    // Use the selected result if we have one; this should always be the case
+    // when the view is open.
+    let result = this.view.selectedResult;
+    if (result) {
+      this.pickResult(event, result);
+      return;
+    }
+
+    // Use the current value if we don't have a UrlbarMatch e.g. because the
+    // view is closed.
     let url = this.value;
     if (!url) {
       return;
@@ -268,6 +278,8 @@ class UrlbarInput {
   pickResult(event, result) {
     this.setValueFromResult(result);
 
+    this.view.close();
+
     // TODO: Work out how we get the user selection behavior, probably via passing
     // it in, since we don't have the old autocomplete controller to work with.
     // BrowserUsageTelemetry.recordUrlbarSelectedResultMethod(

browser/components/urlbar/UrlbarView.jsm

@@ -54,6 +54,19 @@ class UrlbarView {
     return this.panel.state == "open" || this.panel.state == "showing";
   }
 
+  /**
+   * @returns {UrlbarMatch}
+   *   The currently selected result.
+   */
+  get selectedResult() {
+    if (!this.isOpen) {
+      return null;
+    }
+
+    let resultIndex = this._selected.getAttribute("resultIndex");
+    return this._queryContext.results[resultIndex];
+  }
+
   /**
    * Selects the next or previous view item. An item could be an autocomplete
    * result or a one-off search button.
@@ -303,7 +316,6 @@ class UrlbarView {
     if (result) {
       this.input.pickResult(event, result);
     }
-    this.close();
   }
 
   _on_overflow(event) {