Changes: write some of the QML docs

- Fix references; I decided to put it in Qml.h, which is
  the header for the code that does the work.

CHANGES

@@ -18,7 +18,7 @@ This release contains contributions from (alphabetically by first name):
    `import` for Calamares parts looks like
    > ```import io.calamares.ui 1.0```
    A complete list of objects available from Calamares van be found in the
-   documentation for the *QmlViewStep* base class.
+   documentation in `Qml.h`.
  - The sidebar (which shows overall progress in the installation) is now
    more configurable: the branding key *sidebar* controls it. The sidebar
    can be shown as a widget (default, as it has been), hidden, or use a

src/libcalamaresui/utils/Qml.h

@@ -32,6 +32,12 @@ namespace CalamaresUtils
  *
  * This needs to be called at least once to make the global Calamares
  * models (Branding, ViewManager, ...) available to QML.
+ *
+ * The following objects are made available globally:
+ *  - `io.calamares.ui.Branding` (an object, see Branding.h)
+ *  - `io.calamares.core.ViewManager` (a model, see ViewManager.h)
+ * Additionally, modules based on QmlViewStep have a context
+ * property `config` referring to that module's configuration (if any).
  */
 UIDLLEXPORT void registerCalamaresModels();
 

src/libcalamaresui/viewpages/QmlViewStep.h

@@ -46,6 +46,8 @@ public:
      * This is set through common configuration key *qmlSearch*.
      * The filename used comes from the module identifier, or can be
      * set in the configuration file through *qmlFilename*.
+     *
+     * @see Qml.h for available Calamares internals.
      */
     QmlViewStep( QObject* parent = nullptr );
     virtual ~QmlViewStep() override;
@@ -78,6 +80,8 @@ protected:
      *
      * Ownership of the config object remains with the ViewStep; it is possible
      * to return a pointer to a member variable.
+     *
+     * This object is made available as a context-property *config* in QML.
      */
     virtual QObject* getConfig();
 

src/modules/notesqml/notesqml.qml

@@ -22,7 +22,7 @@
  * by Calamares). One of the internals that is exposed in the sub-
  * namespace io.calamares.ui is the Branding object, which can be used
  * to retrieve strings and paths and colors. For a full list, see
- * the documentation of the QmlViewStep base-class.
+ * the documentation in `Qml.h`.
  */
 import io.calamares.ui 1.0