49a50
>     private static final String COMMAND_OPEN_EXTERNAL = "openexternal";
164a166,169
>         JButton btnOpenExternal = new JButton(new ImageAction(COMMAND_OPEN_EXTERNAL,
>                 ImageProvider.get("open"), tr("Open in external viewer")));
>         btnOpenExternal.setPreferredSize(buttonDim);
> 
180a186
>         buttons.add(btnOpenExternal);
250a257,260
>             } else if (COMMAND_OPEN_EXTERNAL.equals(action)) {
>                 if (currentLayer != null) {
>                     currentLayer.openCurrentPhotoInExternalViewer();
>                 }
