[ConfigModel] Allow programmatically adding and removing ConfigCategory

The appendCategory(ConfigCategory*) allows to add a category created by e.g. an Instantiator
that can use bindings rather than fixed arguments.
The removeCategory methods allow to remove a category when e.g. the model in an Instantiator resets.

CCBUG: 372090

Differential Revision: https://phabricator.kde.org/D7602

src/plasmaquick/configmodel.cpp

@@ -57,6 +57,8 @@ public:
     QHash<QString, KQuickAddons::ConfigModule *> kcms;
 
     void appendCategory(ConfigCategory *c);
+    void removeCategory(ConfigCategory *c);
+    void removeCategoryAt(int index);
     void clear();
     QVariant get(int row) const;
 
@@ -154,6 +156,31 @@ void ConfigModelPrivate::appendCategory(ConfigCategory *c)
     emit q->countChanged();
 }
 
+void ConfigModelPrivate::removeCategory(ConfigCategory *c)
+{
+    const int index = categories.indexOf(c);
+    if (index > -1) {
+        removeCategoryAt(index);
+    }
+}
+
+void ConfigModelPrivate::removeCategoryAt(int index)
+{
+    if (index < 0 || index >= categories.count()) {
+        return;
+    }
+
+    q->beginRemoveRows(QModelIndex(), index, index);
+
+    ConfigCategory *c = categories.takeAt(index);
+    if (c->parent() == q) {
+        c->deleteLater();
+    }
+
+    q->endRemoveRows();
+    emit q->countChanged();
+}
+
 QVariant ConfigModelPrivate::get(int row) const
 {
     QVariantMap value;
@@ -287,6 +314,21 @@ void ConfigModel::appendCategory(const QString &iconName, const QString &name,
     d->appendCategory(cat);
 }
 
+void ConfigModel::appendCategory(ConfigCategory *category)
+{
+    d->appendCategory(category);
+}
+
+void ConfigModel::removeCategory(ConfigCategory *category)
+{
+    d->removeCategory(category);
+}
+
+void ConfigModel::removeCategoryAt(int index)
+{
+    d->removeCategoryAt(index);
+}
+
 void ConfigModel::clear()
 {
     d->clear();

src/plasmaquick/configmodel.h

@@ -85,6 +85,11 @@ public:
 
     Q_INVOKABLE void appendCategory(const QString &iconName, const QString &name,
                         const QString &path, const QString &pluginName, bool visible);
+    // QML Engine isn't particulary smart resolving namespaces, hence fully qualified signature
+    Q_INVOKABLE void appendCategory(PlasmaQuick::ConfigCategory *category);
+
+    Q_INVOKABLE void removeCategory(PlasmaQuick::ConfigCategory *category);
+    Q_INVOKABLE void removeCategoryAt(int index);
 
     /**
      * clears the model