Add a placeholder File→Save menubar item

It is toggled enabled when the user edits text,
and provisionally displays a pop-up message
saying “I do nothing lol”.

contact.scm

@@ -48,13 +48,26 @@
 
 ;; Connect callback functions to widgets’ signals.
 (define (window-callbacks window)
-  (let* ([file→exit (qt:find window "actionQuit")])
+  (menubar-callbacks window)
+  (textbox-callbacks window))
+
+
+
+;; Connect callback functions to menubar items.
+(define (menubar-callbacks window)
+  (let* ([file→exit (qt:find window "actionQuit")]
+         [file→save (qt:find window "actionSave")])
     ;; We connect to https://doc.qt.io/qt-6/qaction.html#triggered
     (if file→exit
         (qt:connect
          file→exit "triggered()"
-         (qt:receiver exit))))
-  (textbox-callbacks window))
+         (qt:receiver exit)))
+    (if file→save
+        (qt:connect
+         file→save "triggered()"
+         (qt:receiver
+          (lambda ()
+            (qt:message "Saving is not implemented." "Saving")))))))
 
 
 ;; Connect a text-printing callback to each textbox.
@@ -71,12 +84,18 @@
     ;; Cycle through each textbox, connecting them to a callback that prints
     ;; their contents each time you type in text.
     (map (lambda (textbox)
+           ;; We connect to https://doc.qt.io/qt-6/qlineedit.html#textChanged
+           ;; … and print the value of https://doc.qt.io/qt-6/qlineedit.html#text-prop
+           ;; Also enable the File→Save menu-item (since, y’know, the user
+           ;; changed something). It defaults to disabled in the contact.ui file.
            (if textbox
-               ;; We connect to https://doc.qt.io/qt-6/qlineedit.html#textChanged
-               ;; … and print the value of https://doc.qt.io/qt-6/qlineedit.html#text-prop
                (qt:connect textbox "textChanged(QString)"
                            (qt:receiver
-                            (lambda () (print (qt:property textbox "text")))))))
+                            (lambda ()
+                              (let ([file→save (qt:find window "actionSave")])
+                                (if file→save
+                                    (set! (qt:property file→save "enabled") #t)))
+                              (print (qt:property textbox "text")))))))
          textboxes)))
 
 

contact.ui

@@ -225,6 +225,7 @@
     <property name="title">
      <string>File</string>
     </property>
+    <addaction name="actionSave"/>
     <addaction name="actionQuit"/>
    </widget>
    <addaction name="menuFile"/>
@@ -235,6 +236,14 @@
     <string>Exit</string>
    </property>
   </action>
+  <action name="actionSave">
+   <property name="enabled">
+    <bool>false</bool>
+   </property>
+   <property name="text">
+    <string>Save</string>
+   </property>
+  </action>
  </widget>
  <resources/>
  <connections/>