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

@@ -47,6 +47,11 @@ Kirigami.AbstractApplicationWindow {
      * This property holds the QQC2 DialogButtonBox used in the footer of the dialog.
      */
     readonly property alias dialogButtonBox: footerButtonBox
+
+    /**
+     * Controls whether the accept button is enabled
+     */
+    property bool acceptable: true
     
     width: column.implicitWidth
     height: column.implicitHeight + footer.implicitHeight
@@ -132,7 +137,14 @@ Kirigami.AbstractApplicationWindow {
                 spacing: Kirigami.Units.smallSpacing
                 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

@@ -56,9 +56,9 @@ Kirigami.AbstractApplicationWindow {
         title: "Authentication Required"
         subtitle: "Authentication is needed to run `/usr/bin/ls` as the super user."
         iconName: "im-user-online"
-        
+
         Kirigami.PasswordField {}
-        
+
         actions: [
             Kirigami.Action {
                 text: "Details"
@@ -77,6 +77,26 @@ 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
@@ -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: {