This is a really advanced task that requires extensive knowledge about Marble and its tour feature.

We'd like to have a Tour UI entry "Add Description" (aka "Add Balloon").

One possible approach would be to add such an entry. Clicking the button

would open up a dialog which allows to enter the Name, the text for the

balloon (Maybe we should/could reuse EditTextAnnotationDialog.* for this which might require moving it out of the plugin). Coordinates would be set to whatever is visible on the center of the screen.

Pressing the ok button of the Dialog would internally create a

TourPrimitive AnimationUpdate::Create which would be visualized in the Tour list view in a way similar to Update Item: just that the label would be "Create Item" instead.

Clicking the Edit icon of the "Create Item" would open up the EditTextAnnotationDialog again and allow for modifying parameters.

In a future task we would add "Delete Item".