1 files changed, 40 insertions, 0 deletions
diff --git a/comm/mail/components/unifiedtoolbar/content/items/compact-folder-button.mjs b/comm/mail/components/unifiedtoolbar/content/items/compact-folder-button.mjs
new file mode 100644
index 0000000000..78abbaef3a
--- /dev/null
+++ b/comm/mail/components/unifiedtoolbar/content/items/compact-folder-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";
+
+/**
+ * Unified toolbar button for compacting the current folder.
+ */
+class CompactFolderButton extends MailTabButton {
+  observed3PaneEvents = ["folderURIChanged"];
+  observedAboutMessageEvents = [];
+
+  onCommandContextChange() {
+    const { gFolder } =
+      document.getElementById("tabmail").currentAbout3Pane ?? {};
+    if (!gFolder) {
+      this.disabled = true;
+      return;
+    }
+    try {
+      this.disabled = !gFolder.isCommandEnabled("cmd_compactFolder");
+    } catch {
+      this.disabled = true;
+    }
+  }
+
+  handleClick = event => {
+    const about3Pane = document.getElementById("tabmail").currentAbout3Pane;
+    if (!about3Pane) {
+      return;
+    }
+    about3Pane.folderPane.compactFolder(about3Pane.gFolder);
+    event.preventDefault();
+    event.stopPropagation();
+  };
+}
+customElements.define("compact-folder-button", CompactFolderButton, {
+  extends: "button",
+});