Replace source ready flag with loading/ready/error enum

src/ol/layer/layer.js

@@ -68,17 +68,17 @@ ol.layer.Layer.prototype.getSource = function() {
 };
 
 
+/**
+  * @inheritDoc
+  */
+ol.layer.Layer.prototype.getSourceState = function() {
+  return this.getSource().getState();
+};
+
+
 /**
  * @private
  */
 ol.layer.Layer.prototype.handleSourceChange_ = function() {
   this.dispatchChangeEvent();
 };
-
-
-/**
- * @inheritDoc
- */
-ol.layer.Layer.prototype.isReady = function() {
-  return this.getSource().isReady();
-};

src/ol/layer/layerbase.js

@@ -7,6 +7,7 @@ goog.require('goog.events.EventType');
 goog.require('goog.math');
 goog.require('goog.object');
 goog.require('ol.Object');
+goog.require('ol.source.State');
 
 
 /**
@@ -29,8 +30,8 @@ ol.layer.LayerProperty = {
  *            contrast: number,
  *            hue: number,
  *            opacity: number,
- *            ready: boolean,
  *            saturation: number,
+ *            sourceState: ol.source.State,
  *            visible: boolean,
  *            maxResolution: number,
  *            minResolution: number}}
@@ -142,8 +143,8 @@ ol.layer.Base.prototype.getLayerState = function() {
   var contrast = this.getContrast();
   var hue = this.getHue();
   var opacity = this.getOpacity();
-  var ready = this.isReady();
   var saturation = this.getSaturation();
+  var sourceState = this.getSourceState();
   var visible = this.getVisible();
   var maxResolution = this.getMaxResolution();
   var minResolution = this.getMinResolution();
@@ -152,8 +153,8 @@ ol.layer.Base.prototype.getLayerState = function() {
     contrast: goog.isDef(contrast) ? Math.max(contrast, 0) : 1,
     hue: goog.isDef(hue) ? hue : 0,
     opacity: goog.isDef(opacity) ? goog.math.clamp(opacity, 0, 1) : 1,
-    ready: ready,
     saturation: goog.isDef(saturation) ? Math.max(saturation, 0) : 1,
+    sourceState: sourceState,
     visible: goog.isDef(visible) ? !!visible : true,
     maxResolution: goog.isDef(maxResolution) ? maxResolution : Infinity,
     minResolution: goog.isDef(minResolution) ? Math.max(minResolution, 0) : 0
@@ -232,6 +233,12 @@ goog.exportProperty(
     ol.layer.Base.prototype.getSaturation);
 
 
+/**
+ * @return {ol.source.State} Source state.
+ */
+ol.layer.Base.prototype.getSourceState = goog.abstractMethod;
+
+
 /**
  * @return {boolean} Visible.
  */
@@ -248,7 +255,7 @@ goog.exportProperty(
  * @protected
  */
 ol.layer.Base.prototype.handleLayerChange = function() {
-  if (this.getVisible() && this.isReady()) {
+  if (this.getVisible() && this.getSourceState() == ol.source.State.READY) {
     this.dispatchChangeEvent();
   }
 };
@@ -258,18 +265,12 @@ ol.layer.Base.prototype.handleLayerChange = function() {
  * @protected
  */
 ol.layer.Base.prototype.handleLayerVisibleChange = function() {
-  if (this.isReady()) {
+  if (this.getSourceState() == ol.source.State.READY) {
     this.dispatchChangeEvent();
   }
 };
 
 
-/**
- * @return {boolean} Is ready.
- */
-ol.layer.Base.prototype.isReady = goog.abstractMethod;
-
-
 /**
  * Adjust the layer brightness.  A value of -1 will render the layer completely
  * black.  A value of 0 will leave the brightness unchanged.  A value of 1 will

src/ol/layer/layergroup.js

@@ -11,6 +11,7 @@ goog.require('ol.CollectionEvent');
 goog.require('ol.CollectionEventType');
 goog.require('ol.Object');
 goog.require('ol.layer.Base');
+goog.require('ol.source.State');
 
 
 /**
@@ -205,6 +206,7 @@ ol.layer.Group.prototype.getLayerStatesArray = function(opt_obj) {
     layerState.hue += ownLayerState.hue;
     layerState.opacity *= ownLayerState.opacity;
     layerState.saturation *= ownLayerState.saturation;
+    layerState.sourceState = this.getSourceState();
     layerState.visible = layerState.visible && ownLayerState.visible;
     layerState.maxResolution = Math.min(
         layerState.maxResolution, ownLayerState.maxResolution);
@@ -219,9 +221,31 @@ ol.layer.Group.prototype.getLayerStatesArray = function(opt_obj) {
 /**
  * @inheritDoc
  */
-ol.layer.Group.prototype.isReady = function() {
-  return null === goog.array.find(
-      this.getLayers().getArray(), function(elt, index, array) {
-        return !elt.isReady();
-      });
+ol.layer.Group.prototype.getSourceState = function() {
+  // Return the layer group's source state based on the best source state of its
+  // children:
+  // - if any child is READY, return READY
+  // - otherwise, if any child is LOADING, return LOADING
+  // - otherwise, all children must be in ERROR, return ERROR
+  // - otherwise, there are no children, return READY
+  var layerSourceStates = [0, 0, 0];
+  var layers = this.getLayers().getArray();
+  var n = layers.length;
+  var i;
+  for (i = 0; i < n; ++i) {
+    var layerSourceState = layers[i].getSourceState();
+    goog.asserts.assert(layerSourceState < layerSourceStates.length);
+    ++layerSourceStates[layerSourceState];
+  }
+  if (layerSourceStates[ol.source.State.READY]) {
+    return ol.source.State.READY;
+  } else if (layerSourceStates[ol.source.State.LOADING]) {
+    return ol.source.State.LOADING;
+  } else if (layerSourceStates[ol.source.State.ERROR]) {
+    goog.asserts.assert(layerSourceStates[ol.source.State.ERROR] == n);
+    return ol.source.State.ERROR;
+  } else {
+    goog.asserts.assert(n === 0);
+    return ol.source.State.READY;
+  }
 };