1 files changed, 40 insertions, 0 deletions
diff --git a/comm/mail/components/unifiedtoolbar/content/items/view-picker-button.mjs b/comm/mail/components/unifiedtoolbar/content/items/view-picker-button.mjs
new file mode 100644
index 0000000000..3cd7686b5e
--- /dev/null
+++ b/comm/mail/components/unifiedtoolbar/content/items/view-picker-button.mjs
@@ -0,0 +1,40 @@
+/* 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/. */
+
+import { MailTabButton } from "chrome://messenger/content/unifiedtoolbar/mail-tab-button.mjs";
+
+class ViewPickerButton extends MailTabButton {
+  observed3PaneEvents = ["folderURIChanged", "MailViewChanged"];
+
+  observedAboutMessageEvents = [];
+
+  /**
+   * Update the label and icon of the button from the currently selected folder
+   * in the local 3pane.
+   */
+  onCommandContextChange() {
+    const { gViewWrapper } =
+      document.getElementById("tabmail").currentAbout3Pane ?? {};
+    if (!gViewWrapper) {
+      this.disabled = true;
+      return;
+    }
+    this.disabled = false;
+    const viewPickerPopup = document.getElementById(this.getAttribute("popup"));
+    const value = window.ViewPickerBinding.currentViewValue;
+    let selectedItem = viewPickerPopup.querySelector(`[value="${value}"]`);
+    if (!selectedItem) {
+      // We may have a new item, so refresh to make it show up.
+      window.RefreshAllViewPopups(viewPickerPopup, true);
+      selectedItem = viewPickerPopup.querySelector(`[value="${value}"]`);
+    }
+    this.label.textContent = selectedItem?.getAttribute("label");
+    if (!this.label.textContent) {
+      document.l10n.setAttributes(this.label, "toolbar-view-picker-label");
+    }
+  }
+}
+customElements.define("view-picker-button", ViewPickerButton, {
+  extends: "button",
+});