Port DOM renderer to request render frame architecture

src/ol/renderer/dom/domtilelayerrenderer.js

@@ -86,16 +86,6 @@ ol.renderer.dom.TileLayer.prototype.removeExtraTiles_ =
 };
 
 
-/**
- * @param {goog.events.Event} event Tile change event.
- * @private
- */
-ol.renderer.dom.TileLayer.prototype.handleTileChange_ = function(event) {
-  goog.asserts.assert(event.target.getState() == ol.TileState.LOADED);
-  this.getMap().render();
-};
-
-
 /**
  * @inheritDoc
  */
@@ -125,6 +115,7 @@ ol.renderer.dom.TileLayer.prototype.renderFrame = function(time) {
   var tileRange =
       tileGrid.getTileRangeForExtentAndResolution(mapExtent, mapResolution);
 
+  var allTilesLoaded = true;
 
   // first pass through the tile range to determine all the tiles needed
   tileRange.forEachTileCoord(z, function(tileCoord) {
@@ -136,17 +127,15 @@ ol.renderer.dom.TileLayer.prototype.renderFrame = function(time) {
 
     var key = tile.tileCoord.toString();
     var state = tile.getState();
-    if (state == ol.TileState.LOADED) {
+    if (state == ol.TileState.IDLE) {
+      tile.load();
+    } else if (state == ol.TileState.LOADED) {
       tilesToDrawByZ[z][key] = tile;
       return;
-    } else {
-      if (state != ol.TileState.LOADING) {
-        goog.events.listen(tile, goog.events.EventType.CHANGE,
-            this.handleTileChange_, false, this);
-        tile.load();
-      }
     }
 
+    allTilesLoaded = false;
+
     /**
      * Look for already loaded tiles at alternate z that can serve as
      * placeholders until tiles at the current z have loaded.
@@ -233,4 +222,6 @@ ol.renderer.dom.TileLayer.prototype.renderFrame = function(time) {
   this.renderedMapResolution_ = mapResolution;
 
   this.removeExtraTiles_(tilesToDrawByZ);
+
+  return !allTilesLoaded;
 };