From a1f7906273ca56273f389fa0aaf8de69bf002321 Mon Sep 17 00:00:00 2001
From: Tino Desjardins <tino.desjardins@arcor.de>
Date: Mon, 24 May 2021 09:54:55 +0200
Subject: [PATCH] Add render order function support

---
 .../java/ol/layer/BaseVectorLayerOptions.java | 22 +++++++++++++
 .../src/main/java/ol/style/OrderFunction.java | 33 +++++++++++++++++++
 .../java/ol/style/OrderFunctionRender.java    | 33 +++++++++++++++++++
 3 files changed, 88 insertions(+)
 create mode 100644 gwt-ol3-client/src/main/java/ol/style/OrderFunction.java
 create mode 100644 gwt-ol3-client/src/main/java/ol/style/OrderFunctionRender.java

diff --git a/gwt-ol3-client/src/main/java/ol/layer/BaseVectorLayerOptions.java b/gwt-ol3-client/src/main/java/ol/layer/BaseVectorLayerOptions.java
index 90aaba9a..65758d14 100644
--- a/gwt-ol3-client/src/main/java/ol/layer/BaseVectorLayerOptions.java
+++ b/gwt-ol3-client/src/main/java/ol/layer/BaseVectorLayerOptions.java
@@ -20,6 +20,8 @@
 
 import jsinterop.annotations.JsType;
 import ol.PluggableMap;
+import ol.style.OrderFunction;
+import ol.style.OrderFunctionRender;
 import ol.style.Style;
 import ol.style.StyleFunction;
 
@@ -67,6 +69,26 @@ public class BaseVectorLayerOptions extends LayerOptions {
     @JsProperty
     public native void setRenderBuffer(double renderBuffer);
 
+    /**
+     * Render order. Function to be used when sorting features before rendering.
+     * By default features are drawn in the order that they are created. Use null
+     * to avoid the sort, but get an undefined draw order.
+     *
+     * @param orderFunction order function
+     */
+    @JsProperty
+    public native void setRenderOrder(OrderFunction orderFunction);
+
+    /**
+     * Render order. Function to be used when sorting features before rendering.
+     * By default features are drawn in the order that they are created. Use null
+     * to avoid the sort, but get an undefined draw order.
+     *
+     * @param orderFunction order function
+     */
+    @JsProperty
+    public native void setRenderOrder(OrderFunctionRender orderFunction);
+
     @JsProperty
     public native void setStyle(Style style);
 
diff --git a/gwt-ol3-client/src/main/java/ol/style/OrderFunction.java b/gwt-ol3-client/src/main/java/ol/style/OrderFunction.java
new file mode 100644
index 00000000..f38f18aa
--- /dev/null
+++ b/gwt-ol3-client/src/main/java/ol/style/OrderFunction.java
@@ -0,0 +1,33 @@
+/*******************************************************************************
+ * Copyright 2014, 2021 gwt-ol
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *******************************************************************************/
+package ol.style;
+
+import jsinterop.annotations.JsFunction;
+import ol.Feature;
+
+/**
+ * A function to be used when sorting features before rendering.
+ *
+ * @author TDesjardins
+ *
+ */
+@FunctionalInterface
+@JsFunction
+public interface OrderFunction {
+
+    double sort(Feature feature1, Feature feature2);
+
+}
\ No newline at end of file
diff --git a/gwt-ol3-client/src/main/java/ol/style/OrderFunctionRender.java b/gwt-ol3-client/src/main/java/ol/style/OrderFunctionRender.java
new file mode 100644
index 00000000..01ebdd0d
--- /dev/null
+++ b/gwt-ol3-client/src/main/java/ol/style/OrderFunctionRender.java
@@ -0,0 +1,33 @@
+/*******************************************************************************
+ * Copyright 2014, 2021 gwt-ol
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *******************************************************************************/
+package ol.style;
+
+import jsinterop.annotations.JsFunction;
+import ol.render.Feature;
+
+/**
+ * A function to be used when sorting features before rendering.
+ *
+ * @author TDesjardins
+ *
+ */
+@FunctionalInterface
+@JsFunction
+public interface OrderFunctionRender {
+
+    double sort(Feature feature1, Feature feature2);
+
+}
\ No newline at end of file