Implement a DesktopSystemDialog.acceptable property

Specifies if the accept button is enabled and otherwise should control
if we can accept the dialog.

components/dialogs/DesktopSystemDialog.qml

@@ -48,6 +48,11 @@ Kirigami.AbstractApplicationWindow {
      */
     readonly property alias dialogButtonBox: footerButtonBox
 
+    /**
+     * Controls whether the accept button is enabled
+     */
+    property bool acceptable: true
+    
     width: column.implicitWidth
     height: column.implicitHeight + footer.implicitHeight
     minimumHeight: column.Layout.minimumHeight + footer.implicitHeight
@@ -133,6 +138,13 @@ Kirigami.AbstractApplicationWindow {
                 onAccepted: root.accept()
                 onRejected: root.reject()
 
+                Binding {
+                    target: footerButtonBox.standardButton(DialogButtonBox.Ok)
+                    property: "enabled"
+                    when: footerButtonBox.standardButton(DialogButtonBox.Ok)
+                    value: root.acceptable
+                }
+
                 Repeater {
                     model: root.actions
                     

components/dialogs/examples/test.qml

@@ -78,6 +78,26 @@ Kirigami.AbstractApplicationWindow {
         ]
     }
 
+    DesktopSystemDialog {
+        id: xdgDialog
+        title: "Wallet access"
+        subtitle: "Share your wallet with 'Somebody'."
+        iconName: "kwallet"
+        acceptable: false
+
+        dialogButtonBox.standardButtons: DialogButtonBox.Ok | DialogButtonBox.Ok
+        Component.onCompleted: {
+            dialogButtonBox.standardButton(DialogButtonBox.Ok).text = "Share"
+        }
+        actions: [
+            Kirigami.Action {
+                text: "Something Happens"
+                iconName: "documentinfo"
+                onTriggered: xdgDialog.acceptable = true
+            }
+        ]
+    }
+    
     DesktopCSDSystemDialog {
         id: desktopCSDPolkit
         title: "Authentication Required"
@@ -293,6 +313,16 @@ Kirigami.AbstractApplicationWindow {
                 }
             }
         }
+        Button {
+            text: "XDG dialog (Desktop)"
+            onClicked: {
+                if (checkbox.checked) {
+                    xdgDialog.showFullScreen()
+                } else {
+                    xdgDialog.show()
+                }
+            }
+        }
         Button {
             text: "Polkit dialog (Mobile)"
             onClicked: {