Improved example

examples/helloworld.qml

@@ -5,10 +5,16 @@ import QtQuick.Controls 2.15
 
 Window {
   id: window
+  objectName: "window"
   visible: true
   width: 800
   height: 600
-  RowLayout {
+  signal close
+  onVisibilityChanged: {
+    if(visibility == Window.Hidden)
+      close()
+  }
+  ColumnLayout {
     id: rowlayout
     anchors.fill: parent
     spacing: 30
@@ -19,16 +25,20 @@ Window {
       color: "lightgray"
       Text {
         id: helloText
+        objectName: "helloText"
         text: "Hello World!"
         y: 30
         anchors.horizontalCenter: parent.horizontalCenter
         font.pointSize: 24; font.bold: true
       }
     }
-    ColumnLayout {
+    RowLayout {
       spacing: 15
       Layout.fillWidth: true
       Layout.fillHeight: true
+      Text {
+        text: qsTr("Change the text above:")
+      }
       TextField {
         id: nameInputField
         objectName: "nameInputField"

examples/helloworld.scm

@@ -1,4 +1,6 @@
 (import
+  (chicken base)
+  srfi-18
   (qml core)
   coops)
 
@@ -21,15 +23,28 @@
 (load-url engine loc)
 
 (define nameInputField (find-child (root engine) "nameInputField"))
+(define helloText (find-child (root engine) "helloText"))
+;; TODO: Why does the following not work?
+(define window (find-child (root engine) "window"))
 
 (define (textChangeCallback cbdata argv) void
-  (print "Text changed to " (to (property nameInputField "text") string:)))
+  (print "Text changed to " (to (property nameInputField "text") string:))
+  (set-property helloText "text" (property nameInputField "text")))
+
+(define (closeProgram cbdata argv) void
+  (print "Window closed, exiting program.")
+  (exit 0))
 
 (define conn2 (connect nameInputField "textEdited()"
                        textChangeCallback
                        textchange-cbdata
                        (qt-connection-type auto:)))
 
+(define conn3 (connect (root engine) "close()"
+                       closeProgram #f
+                       (qt-connection-type auto:)))
+
 (do ((loop #t))
   ((not loop) #t)
+  (thread-sleep! (seconds->time (+ 0.05 (time->seconds (current-time)))))
   (process-events-timed (qevent-loop-process-event-flag process-all-events:) 50))

qml.core.scm

@@ -416,7 +416,8 @@
     (dos_qobject_disconnect_with_connection_static (slot-value qmoc 'ptr)))
 
   (define-method (delete-pointer (qmoc <QMetaObjectConnection>))
-    ;; TODO: try-catch disconnect
+    (handle-exceptions exn #t
+      (disconnect qmoc))
     (object-release (pointer->object (alist-ref intern-data-pointer: (hash-table-ref lambda-static-callbacks (callback-key qmoc)))))
     (hash-table-delete! lambda-static-callbacks (callback-key qmoc))
     (dos_qmetaobject_connection_delete (slot-value qmoc 'ptr)))