Bug 1709129 - Open downloads panel when new download starts. r=Gijs

Differential Revision: https://phabricator.services.mozilla.com/D118186

browser/components/downloads/DownloadsCommon.jsm

@@ -941,7 +941,18 @@ DownloadsDataCtor.prototype = {
       return;
     }
 
-    if (this.panelHasShownBefore && aType != "error") {
+    let shouldOpenDownloadsPanel =
+      aType == "start" &&
+      Services.prefs.getBoolPref(
+        "browser.download.improvements_to_download_panel"
+      ) &&
+      DownloadsCommon.summarizeDownloads(this.downloads).numDownloading <= 1;
+
+    if (
+      this.panelHasShownBefore &&
+      aType != "error" &&
+      !shouldOpenDownloadsPanel
+    ) {
       // For new downloads after the first one, don't show the panel
       // automatically, but provide a visible notification in the topmost
       // browser window, if the status indicator is already visible.

browser/components/downloads/test/browser/browser.ini

@@ -30,6 +30,7 @@ skip-if = true # Bug 1352792
 [browser_downloads_panel_context_menu.js]
 [browser_downloads_panel_ctrl_click.js]
 [browser_downloads_panel_height.js]
+[browser_downloads_panel_opens.js]
 [browser_downloads_autohide.js]
 [browser_go_to_download_page.js]
 [browser_pdfjs_preview.js]

browser/components/downloads/test/browser/browser_downloads_panel_opens.js

@@ -0,0 +1,77 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Make sure the downloads panel opens automatically with a new download.
+ */
+add_task(async function test_downloads_panel_opens() {
+  await SpecialPowers.pushPrefEnv({
+    set: [["browser.download.improvements_to_download_panel", true]],
+  });
+
+  info("waiting for panel to open");
+  let promise = promisePanelOpened();
+  DownloadsCommon.getData(window)._notifyDownloadEvent("start");
+  is(
+    DownloadsPanel.isPanelShowing,
+    true,
+    "Panel state should indicate a preparation to be opened"
+  );
+  await promise;
+
+  is(DownloadsPanel.panel.state, "open", "Panel should be opened");
+
+  DownloadsPanel.hidePanel();
+});
+
+/**
+ * Make sure the downloads panel opens automatically with new download, only if  no other downloads are in progress.
+ */
+add_task(async function test_downloads_panel_remains_closed() {
+  await SpecialPowers.pushPrefEnv({
+    set: [["browser.download.improvements_to_download_panel", true]],
+  });
+  await task_addDownloads([
+    { state: DownloadsCommon.DOWNLOAD_DOWNLOADING },
+    { state: DownloadsCommon.DOWNLOAD_DOWNLOADING },
+  ]);
+
+  let publicList = await Downloads.getList(Downloads.PUBLIC);
+  let downloads = await publicList.getAll();
+
+  info("setting 2 downloads to be in progress");
+  downloads[0].stopped = false;
+  downloads[1].stopped = false;
+
+  let oldShowEventNotification = DownloadsIndicatorView.showEventNotification;
+
+  registerCleanupFunction(async () => {
+    // Remove all downloads created during the test.
+    for (let download of downloads) {
+      await publicList.remove(download);
+    }
+    DownloadsIndicatorView.showEventNotification = oldShowEventNotification;
+  });
+
+  let promiseDownloadStartedNotification = new Promise(resolve => {
+    // Instead of downloads panel opening, download notification should be shown.
+    DownloadsIndicatorView.showEventNotification = aType => {
+      if (aType == "start") {
+        DownloadsIndicatorView.showEventNotification = oldShowEventNotification;
+        resolve();
+      }
+    };
+  });
+
+  DownloadsCommon.getData(window)._notifyDownloadEvent("start");
+
+  is(
+    DownloadsPanel.isPanelShowing,
+    false,
+    "Panel state should NOT indicate a preparation to be opened"
+  );
+
+  await promiseDownloadStartedNotification;
+
+  is(DownloadsPanel.panel.state, "closed", "Panel should be closed");
+});