From 2842d1b2540b9bfe68532ec19caa5fee4ed26b63 Mon Sep 17 00:00:00 2001
From: Tom Payne <twpayne@gmail.com>
Date: Tue, 4 Mar 2014 15:59:58 +0100
Subject: [PATCH] Add ol.loading

---
 src/ol/loading.exports |  3 +++
 src/ol/loading.js      | 52 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+)
 create mode 100644 src/ol/loading.exports
 create mode 100644 src/ol/loading.js

diff --git a/src/ol/loading.exports b/src/ol/loading.exports
new file mode 100644
index 0000000000..7564c21668
--- /dev/null
+++ b/src/ol/loading.exports
@@ -0,0 +1,3 @@
+@exportSymbol ol.loading.all
+@exportSymbol ol.loading.bbox
+@exportSymbol ol.loading.createTile
diff --git a/src/ol/loading.js b/src/ol/loading.js
new file mode 100644
index 0000000000..272d3b2887
--- /dev/null
+++ b/src/ol/loading.js
@@ -0,0 +1,52 @@
+goog.provide('ol.loading');
+
+goog.require('ol.TileCoord');
+
+
+/**
+ * @param {ol.Extent} extent Extent.
+ * @param {number} resolution Resolution.
+ * @return {Array.<ol.Extent>} Extents.
+ */
+ol.loading.all = function(extent, resolution) {
+  return [[-Infinity, -Infinity, Infinity, Infinity]];
+};
+
+
+/**
+ * @param {ol.Extent} extent Extent.
+ * @param {number} resolution Resolution.
+ * @return {Array.<ol.Extent>} Extents.
+ */
+ol.loading.bbox = function(extent, resolution) {
+  return [extent];
+};
+
+
+/**
+ * @param {ol.tilegrid.TileGrid} tileGrid Tile grid.
+ * @return {function(ol.Extent, number): Array.<ol.Extent>} Loading strategy.
+ */
+ol.loading.createTile = function(tileGrid) {
+  return (
+      /**
+       * @param {ol.Extent} extent Extent.
+       * @param {number} resolution Resolution.
+       * @return {Array.<ol.Extent>} Extents.
+       */
+      function(extent, resolution) {
+        var z = tileGrid.getZForResolution(resolution);
+        var tileRange = tileGrid.getTileRangeForExtentAndZ(extent, z);
+        /** @type {Array.<ol.Extent>} */
+        var extents = [];
+        var tileCoord = new ol.TileCoord(z, 0, 0);
+        for (tileCoord.x = tileRange.minX; tileCoord.x <= tileRange.maxX;
+             ++tileCoord.x) {
+          for (tileCoord.y = tileRange.minY; tileCoord.y <= tileRange.maxY;
+               ++tileCoord.y) {
+            extents.push(tileGrid.getTileCoordExtent(tileCoord));
+          }
+        }
+        return extents;
+      });
+};