gui: Add context menu entry to close all applets

This is occasionally very useful if a large number of
applets were left open (e.g. spawned via CCB).

RELEASE_NOTES.rst

@@ -37,6 +37,8 @@ Highlights:
    - A "Quick Open" dialog to open experiments by typing part of their name can
      be brought up Ctrl-P (Ctrl+Return to immediately submit the selected entry
      with the default arguments).
+   - The Applets dock now has a context menu command to quickly close all open
+     applets (shortcut: Ctrl-Alt-W).
 * Experiment results are now always saved to HDF5, even if run() fails.
 * Core device: ``panic_reset 1`` now correctly resets the kernel CPU as well if
   communication CPU panic occurs.

artiq/gui/applets.py

@@ -370,6 +370,11 @@ class AppletsDock(QtWidgets.QDockWidget):
         delete_action.setShortcutContext(QtCore.Qt.WidgetShortcut)
         delete_action.triggered.connect(self.delete)
         self.table.addAction(delete_action)
+        close_all_action = QtWidgets.QAction("Close all applets", self.table)
+        close_all_action.setShortcut("CTRL+ALT+W")
+        close_all_action.setShortcutContext(QtCore.Qt.ApplicationShortcut)
+        close_all_action.triggered.connect(self.close_all)
+        self.table.addAction(close_all_action)
         new_group_action = QtWidgets.QAction("New group", self.table)
         new_group_action.triggered.connect(partial(self.new_with_parent, self.new_group))
         self.table.addAction(new_group_action)
@@ -641,3 +646,14 @@ class AppletsDock(QtWidgets.QDockWidget):
 
     def restore_state(self, state):
         self.restore_state_item(state, None)
+
+    def close_all(self):
+        def walk(wi):
+            for i in range(wi.childCount()):
+                cwi = wi.child(i)
+                if cwi.ty == "applet":
+                    if cwi.checkState(0) == QtCore.Qt.Checked:
+                        cwi.setCheckState(0, QtCore.Qt.Unchecked)
+                elif cwi.ty == "group":
+                    walk(cwi)
+        walk(self.table.invisibleRootItem())