[PATCH] GeoImageLayer functionality enhancements

[holgermappt]

This patch adds functionality to the GeoImageLayer. Added functionality includes:

• flag for changed GPS data
• switch thumbnail display on and off
• create the layer with more options
• query current photo
• usability enhancements

Most of the new functionality is needed for a plug-in that I wrote. That plug-in implements ticket #7712.

Detailed changes:

• Flag ImageEntry.isNewGpsData: The current mode allows to set the coordinates of a photo if it is correlated with a GPX track. That always sets gpsTime, thus gpsTime is used to decide which photo has new coordinates. But there are ways to set the coordinates that do not provide a time. The idea is to use isNewGpsData instead to flag that one of the GPS related data changed. ImageEntry.exifGpsTime is a temporary source of the GPS time and extracted from EXIF.
• Thumbnail toggle feature: GeoImageLayer.useThumbs now acts a thumbnail/symbol toggle variable.
• More GeoImageLayer constructors for different combinations of layer name and thumbnail display status. I use the "name" to create a layer with untagged photos.
• GeoImageLayer.getPhotoUnderMouse() is used to query the photo that is dragged.
• GeoImageLayer.removePhotoByIdx() can be used to remove e.g. untagged photos from current layer.
• GeoImageLayer.clearCurrentPhoto() / clearOtherCurrentPhotos(): The current implementation highlights one photo per GeoImageLayer, which is confusing if there is more than one such layer. The functions clear the select marker from the other layers.
• GeoImageLayer.supportedMapModes / registerSupportedMapMode() / isSupportedMapMode(): Allows to register more modes where the functionality of the GeoImageLayer should be available. This is mainly the possibility to click on a photo that is selected and displayed.
• ImageViewerDialog.displayImage().imageChanged: I re-display a photo if GPS data was changed to update the photo OSD. The flags keeps the current zoom and the area of the photo that is displayed.
• ImageViewerDialog.getCurrentImage() / getCurrentLayer(): Used to query which photo is displayed. That photo can then be positioned on the map.
• GeoImageSessionExporter / GeoImageSessionImporter: Added show-thumbnails (useThumbs), is-new-gps-data (isNewGpsData), exif-gps-time (exifGpsTime). Fixed exif-orientation tag name in importer.

[holgermappt]

GeoImageLayer patch

[holgermappt]

corrected method name flagNewGpsData()

[Don-vip]

In 6392/josm:

fix #9274 - GeoImageLayer functionality enhancements (patch by holgerosm)

[Don-vip]

Thanks for the patch !

[stoecker]

Milestone renamed