add layer option to populate default value for new annotations

pandora/config.pandora.jsonc

@@ -864,6 +864,8 @@ examples (config.SITENAME.jsonc) that are part of this pan.do/ra distribution.
         "canPlayClips": If true, clips from this layer will play for users
             with canPlayClips access
         "entity": ID of the referenced entity (if type is "entity")
+        "getDefaults": function in pandora namespace that gets called
+            to populate defaults for new annotations. i.e. getCurrentFrameAnnotation
         "hasEvents": If true, the calendar will be populated with matches from
             this layer
         "hasPlaces": If true, the map will be populated with matches from this

static/js/editor.js

@@ -114,7 +114,8 @@ pandora.ui.editor = function(data) {
                 // async to not capture keyboard input
                 setTimeout(function() {
                     var created = Ox.formatDate(new Date(), '%Y-%m-%dT%H:%M:%SZ'),
-                        type = Ox.getObjectById(pandora.site.layers, data.layer).type;
+                        layer = Ox.getObjectById(pandora.site.layers, data.layer),
+                        type = layer.type;
                     that.addAnnotation(data.layer, Ox.extend(
                         {
                             created: created,
@@ -131,7 +132,8 @@ pandora.ui.editor = function(data) {
                             place: {lat: null, lng: null}
                         } : type == 'event' ? {
                             event: {start: '', end: ''}
-                        } : {}
+                        } : {},
+                        layer.getDefaults ? pandora[layer.getDefaults](data) : {}
                     ));
                     Ox.Request.clearCache();
                 });

static/js/utils.js

@@ -1274,6 +1274,15 @@ pandora.getClipVideos = function(clip, resolution) {
     }));
 };
 
+pandora.getCurrentFrameAnnotation = function(data) {
+    var ui = pandora.user.ui,
+        position = ui.videoPoints[ui.item].position,
+        resolution = Ox.max(pandora.site.video.resolutions);
+    return {
+        value: '<img src="/' + ui.item + '/' + resolution + 'p' + position + '.jpg">\n\n'
+    };
+};
+
 (function() {
     var itemTitles = {}, documentTitles = {};
     pandora.getWindowTitle = function(itemData) {