Optional zIndex for text symbolizers

src/objectliterals.jsdoc

@@ -748,6 +748,7 @@
  * @property {number|ol.expr.Expression|undefined} fontSize Font size in pixels.
  * @property {string|ol.expr.Expression} text Text for the label.
  * @property {number|ol.expr.Expression|undefined} opacity Opacity (0-1).
+ * @property {number|ol.expr.Expression|undefined} zIndex Stack order.
  */
 
 /**

src/ol/style/textliteral.js

@@ -9,7 +9,8 @@ goog.require('ol.style.Literal');
  *            fontFamily: string,
  *            fontSize: number,
  *            text: string,
- *            opacity: number}}
+ *            opacity: number,
+ *            zIndex: (number|undefined)}}
  */
 ol.style.TextLiteralOptions;
 
@@ -42,6 +43,9 @@ ol.style.TextLiteral = function(options) {
   /** @type {number} */
   this.opacity = options.opacity;
 
+  /** @type {number|undefined} */
+  this.zIndex = options.zIndex;
+
 };
 goog.inherits(ol.style.TextLiteral, ol.style.Literal);
 
@@ -49,9 +53,10 @@ goog.inherits(ol.style.TextLiteral, ol.style.Literal);
 /**
  * @inheritDoc
  */
-ol.style.TextLiteral.prototype.equals = function(textLiteral) {
-  return this.color == textLiteral.color &&
-      this.fontFamily == textLiteral.fontFamily &&
-      this.fontSize == textLiteral.fontSize &&
-      this.opacity == textLiteral.opacity;
+ol.style.TextLiteral.prototype.equals = function(other) {
+  return this.color == other.color &&
+      this.fontFamily == other.fontFamily &&
+      this.fontSize == other.fontSize &&
+      this.opacity == other.opacity &&
+      this.zIndex == other.zIndex;
 };

src/ol/style/textsymbolizer.js

@@ -60,6 +60,15 @@ ol.style.Text = function(options) {
       (options.opacity instanceof ol.expr.Expression) ?
           options.opacity : new ol.expr.Literal(options.opacity);
 
+  /**
+   * @type {ol.expr.Expression}
+   * @private
+   */
+  this.zIndex_ = !goog.isDefAndNotNull(options.zIndex) ?
+      null :
+      (options.zIndex instanceof ol.expr.Expression) ?
+          options.zIndex : new ol.expr.Literal(options.zIndex);
+
 };
 goog.inherits(ol.style.Text, ol.style.Symbolizer);
 
@@ -93,12 +102,19 @@ ol.style.Text.prototype.createLiteral = function(featureOrType) {
   var opacity = Number(ol.expr.evaluateFeature(this.opacity_, feature));
   goog.asserts.assert(!isNaN(opacity), 'opacity must be a number');
 
+  var zIndex;
+  if (!goog.isNull(this.zIndex_)) {
+    zIndex = Number(ol.expr.evaluateFeature(this.zIndex_, feature));
+    goog.asserts.assert(!isNaN(zIndex), 'zIndex must be a number');
+  }
+
   return new ol.style.TextLiteral({
     color: color,
     fontFamily: fontFamily,
     fontSize: fontSize,
     text: text,
-    opacity: opacity
+    opacity: opacity,
+    zIndex: zIndex
   });
 };
 
@@ -148,6 +164,15 @@ ol.style.Text.prototype.getText = function() {
 };
 
 
+/**
+ * Get the zIndex.
+ * @return {ol.expr.Expression} Text.
+ */
+ol.style.Text.prototype.getZIndex = function() {
+  return this.zIndex_;
+};
+
+
 /**
  * Set the font color.
  * @param {ol.expr.Expression} color Font color.
@@ -198,6 +223,16 @@ ol.style.Text.prototype.setText = function(text) {
 };
 
 
+/**
+ * Set the zIndex.
+ * @param {ol.expr.Expression} zIndex Text.
+ */
+ol.style.Text.prototype.setZIndex = function(zIndex) {
+  goog.asserts.assertInstanceof(zIndex, ol.expr.Expression);
+  this.zIndex_ = zIndex;
+};
+
+
 /**
  * @typedef {{color: string,
  *            fontFamily: string,

test/spec/ol/style/textliteral.test.js

@@ -54,12 +54,21 @@ describe('ol.style.TextLiteral', function() {
         text: 'Text is not compared for equality',
         opacity: 0.5
       });
+      var differentZIndex = new ol.style.TextLiteral({
+        color: '#ff0000',
+        fontFamily: 'Arial',
+        fontSize: 11,
+        text: 'Test',
+        opacity: 0.5,
+        zIndex: 3
+      });
       expect(literal.equals(equalLiteral)).to.be(true);
       expect(literal.equals(differentLiteral1)).to.be(false);
       expect(literal.equals(differentLiteral2)).to.be(false);
       expect(literal.equals(differentLiteral3)).to.be(false);
       expect(literal.equals(differentLiteral4)).to.be(false);
       expect(literal.equals(equalLiteral2)).to.be(true);
+      expect(literal.equals(differentZIndex)).to.be(false);
     });
 
   });

test/spec/ol/style/textsymbolizer.test.js

@@ -26,6 +26,18 @@ describe('ol.style.Text', function() {
       expect(symbolizer).to.be.a(ol.style.Text);
     });
 
+    it('accepts zIndex', function() {
+      var symbolizer = new ol.style.Text({
+        color: '#ff0000',
+        fontFamily: 'Arial',
+        fontSize: 11,
+        text: 'Test',
+        opacity: 0.6,
+        zIndex: 3
+      });
+      expect(symbolizer).to.be.a(ol.style.Text);
+    });
+
   });
 
   describe('#createLiteral()', function() {