feat(HideAnnotation): Hide button added to annotations to make them q…

[lilysikes]

…uickly removeable.

#495

[wallw-teal]

The button works but there needs to be an similarly easy method to turn them back on. I also assume that the checkbox doesn't represent the "Show Annotation" state because it is also considering whether or not the geometry is shown? @schmidtk ?

[welchyd]

Annotations don't currently show on geometries (also happens on tracks - #353), so for now the checkbox represents the shown state of the annotation - we need to decide on if the annotation should be tied to the geometry or a separate entity.
I'm in favor of combining them - have the annotation be a label or the floating text and in that case I could see having an icon on the note to show and even toggle the visibility of the annotation itself.

[schmidtk]

KML nodes that support showing an annotation should have a show/hide annotation button in their Layers window UI to toggle the annotation on/off. We still need to work on which nodes support annotations (see the linked track ticket), so we don't need to tackle that here.

That button should control the show flag in os.annotation.OPTIONS_FIELD on the feature, which should in turn control if the annotation exists or not (dispose it if false, create if true). We should not be exposing the annotation via a getAnnotation function to call setVisible because the annotation visibility is impacted by multiple things (node visibility, annotation show flag, timeline) and the overall state is managed by the node.

When the show flag is changed on the feature's annotation options, the node should update the annotation by either disposing the existing annotation or creating a new one. We should update plugin.file.kml.ui.KMLNode#loadAnnotation to handle both of these cases (it currently only handles creating the annotation if one doesn't exist and the flag is true).

If you need a way to notify the node that the option has changed, you can fire a os.events.PropertyChangeEvent on the feature and handle it in plugin.file.kml.ui.KMLNode#onFeatureChange.