Reworked attribution handling

src/ol/source/bingmaps.js

@@ -1,7 +1,6 @@
 goog.provide('ol.source.BingMaps');
 
 goog.require('ol');
-goog.require('ol.Attribution');
 goog.require('ol.TileUrlFunction');
 goog.require('ol.extent');
 goog.require('ol.net');
@@ -81,14 +80,12 @@ ol.inherits(ol.source.BingMaps, ol.source.TileImage);
  * The attribution containing a link to the Microsoft® Bing™ Maps Platform APIs’
  * Terms Of Use.
  * @const
- * @type {ol.Attribution}
+ * @type {string}
  * @api
  */
-ol.source.BingMaps.TOS_ATTRIBUTION = new ol.Attribution({
-  html: '<a class="ol-attribution-bing-tos" ' +
+ol.source.BingMaps.TOS_ATTRIBUTION = '<a class="ol-attribution-bing-tos" ' +
       'href="https://www.microsoft.com/maps/product/terms.html">' +
-      'Terms of Use</a>'
-});
+      'Terms of Use</a>';
 
 
 /**
@@ -181,31 +178,32 @@ ol.source.BingMaps.prototype.handleImageryMetadataResponse = function(response)
     var transform = ol.proj.getTransformFromProjections(
         ol.proj.get('EPSG:4326'), this.getProjection());
 
-    var attributions = resource.imageryProviders.map(function(imageryProvider) {
-      var html = imageryProvider.attribution;
-      /** @type {Object.<string, Array.<ol.TileRange>>} */
-      var tileRanges = {};
-      imageryProvider.coverageAreas.forEach(function(coverageArea) {
-        var minZ = coverageArea.zoomMin;
-        var maxZ = Math.min(coverageArea.zoomMax, maxZoom);
-        var bbox = coverageArea.bbox;
-        var epsg4326Extent = [bbox[1], bbox[0], bbox[3], bbox[2]];
-        var extent = ol.extent.applyTransform(epsg4326Extent, transform);
-        var tileRange, z, zKey;
-        for (z = minZ; z <= maxZ; ++z) {
-          zKey = z.toString();
-          tileRange = tileGrid.getTileRangeForExtentAndZ(extent, z);
-          if (zKey in tileRanges) {
-            tileRanges[zKey].push(tileRange);
-          } else {
-            tileRanges[zKey] = [tileRange];
+    this.setAttributions(function(frameState) {
+      var attributions = [];
+      var zoom = frameState.viewState.zoom;
+      resource.imageryProviders.map(function(imageryProvider) {
+        var intersects = false;
+        var coverageAreas = imageryProvider.coverageAreas;
+        for (var i = 0, ii = coverageAreas.length; i < ii; ++i) {
+          var coverageArea = coverageAreas[i];
+          if (zoom >= coverageArea.zoomMin && zoom <= coverageArea.zoomMax) {
+            var bbox = coverageArea.bbox;
+            var epsg4326Extent = [bbox[1], bbox[0], bbox[3], bbox[2]];
+            var extent = ol.extent.applyTransform(epsg4326Extent, transform);
+            if (ol.extent.intersects(extent, frameState.extent)) {
+              intersects = true;
+              break;
+            }
           }
         }
+        if (intersects) {
+          attributions.push(imageryProvider.attribution);
+        }
       });
-      return new ol.Attribution({html: html, tileRanges: tileRanges});
+
+      attributions.push(ol.source.BingMaps.TOS_ATTRIBUTION);
+      return attributions;
     });
-    attributions.push(ol.source.BingMaps.TOS_ATTRIBUTION);
-    this.setAttributions(attributions);
   }
 
   this.setLogo(brandLogoUri);