add icon/titleChanged

make it possible to set icon and title from
the Applet subclass, making appletInterface (so plasmoid obj)
notice about the change and relay the notify signal

src/plasma/applet.cpp

@@ -335,9 +335,14 @@ QString Applet::title() const
     return i18n("Unknown");
 }
 
-void Applet::setTitle(const QString &title) const
+void Applet::setTitle(const QString &title)
 {
+    if (title == d->customTitle) {
+        return;
+    }
+
     d->customTitle = title;
+    emit titleChanged(title);
 }
 
 QString Applet::icon() const
@@ -347,7 +352,12 @@ QString Applet::icon() const
 
 void Applet::setIcon(const QString &icon)
 {
+    if (icon == d->icon) {
+        return;
+    }
+
     d->icon = icon;
+    emit iconChanged(icon);
 }
 
 KPluginInfo Applet::pluginInfo() const

src/plasma/applet.h

@@ -71,8 +71,8 @@ class PLASMA_EXPORT Applet : public QObject
     Q_PROPERTY(Plasma::Types::ImmutabilityType immutability READ immutability WRITE setImmutability NOTIFY immutabilityChanged)
     Q_PROPERTY(Plasma::Types::FormFactor formFactor READ formFactor NOTIFY formFactorChanged)
     Q_PROPERTY(Plasma::Types::Location location READ location NOTIFY locationChanged)
-    Q_PROPERTY(QString title READ title WRITE setTitle FINAL)
+    Q_PROPERTY(QString title READ title WRITE setTitle NOTIFY titleChanged FINAL)
-    Q_PROPERTY(QString icon READ icon WRITE setIcon FINAL)
+    Q_PROPERTY(QString icon READ icon WRITE setIcon NOTIFY iconChanged FINAL)
 
 public:
 //CONSTRUCTORS
@@ -290,7 +290,7 @@ public:
      * @since 5.0
      * @param title the user-visible title for the applet.
      */
-    void setTitle(const QString &title) const;
+    void setTitle(const QString &title);
 
     /**
      * Attempts to load an applet from a package
@@ -419,6 +419,18 @@ Q_SIGNALS:
      */
     void destroyedChanged(bool destroyed);
 
+    /**
+     * Emitted when the title has changed
+     * @since 5.20
+     */
+    void titleChanged(const QString &title);
+
+    /**
+     * Emitted when the icon name for the applet has changed
+     * @since 5.20
+     */
+    void iconChanged(const QString &icon);
+
 //CONFIGURATION
     /**
      * Emitted when an applet has changed values in its configuration

src/scriptengines/qml/plasmoid/appletinterface.cpp

@@ -80,6 +80,12 @@ AppletInterface::AppletInterface(DeclarativeAppletScript *script, const QVariant
     connect(applet(), &Plasma::Applet::destroyedChanged,
             this, &AppletInterface::destroyedChanged);
 
+    connect(applet(), &Plasma::Applet::titleChanged,
+            this, &AppletInterface::titleChanged);
+
+    connect(applet(), &Plasma::Applet::iconChanged,
+            this, &AppletInterface::iconChanged);
+
     connect(applet(), &Plasma::Applet::activated,
             this, &AppletInterface::activated);