add support for sourcetype: 'image' layers

Author: etpinard

src/plots/mapbox/layers.js

@@ -212,6 +212,9 @@ function convertSourceOpts(opts) {
     } else if(sourceType === 'raster') {
         field = 'tiles';
         sourceOpts.tileSize = 256;
+    } else if(sourceType === 'image') {
+        field = 'url';
+        sourceOpts.coordinates = opts.coordinates;
     }
 
     sourceOpts[field] = source;

src/plots/mapbox/layout_attributes.js

@@ -102,12 +102,11 @@ var attrs = module.exports = overrideAll({
         },
         sourcetype: {
             valType: 'enumerated',
-            values: ['geojson', 'vector', 'raster'],
+            values: ['geojson', 'vector', 'raster', 'image'],
             dflt: 'geojson',
             role: 'info',
             description: [
-                'Sets the source type for this layer.',
-                'Support for *raster*, *image* and *video* source types is coming soon.'
+                'Sets the source type for this layer.'
             ].join(' ')
         },
 
@@ -145,6 +144,17 @@ var attrs = module.exports = overrideAll({
             ].join(' ')
         },
 
+        coordinates: {
+            valType: 'any',
+            role: 'info',
+            description: [
+                'Sets the coordinates array contains [longitude, latitude] pairs',
+                'for the image corners listed in clockwise order:',
+                'top left, top right, bottom right, bottom left.',
+                'Only has an effect for *image* `sourcetype`.'
+            ].join(' ')
+        },
+
         // attributes shared between all types
         below: {
             valType: 'string',

src/plots/mapbox/layout_defaults.js

@@ -54,7 +54,13 @@ function handleLayerDefaults(layerIn, layerOut) {
         var sourceType = coerce('sourcetype');
         coerce('source');
 
-        if(sourceType === 'vector') coerce('sourcelayer');
+        if(sourceType === 'vector') {
+            coerce('sourcelayer');
+        }
+
+        if(sourceType === 'image') {
+            coerce('coordinates');
+        }
 
         // maybe add smart default based off GeoJSON geometry?
         var type = coerce('type');