From e94c7b6c394001592e8b6beb2785e48d4bb20a89 Mon Sep 17 00:00:00 2001
From: Tim Schaub <tim.schaub@gmail.com>
Date: Thu, 15 Aug 2019 10:25:05 -0600
Subject: [PATCH] Only set frameState.animate true if in transition and alpha <
 1

---
 src/ol/renderer/canvas/TileLayer.js |  5 +-
 test/spec/ol/layer/tile.test.js     | 72 ++++++++++++++++++++++++++++-
 test/spec/ol/map.test.js            |  1 +
 3 files changed, 75 insertions(+), 3 deletions(-)

diff --git a/src/ol/renderer/canvas/TileLayer.js b/src/ol/renderer/canvas/TileLayer.js
index a8e35dbe2a..80a799edf9 100644
--- a/src/ol/renderer/canvas/TileLayer.js
+++ b/src/ol/renderer/canvas/TileLayer.js
@@ -377,7 +377,8 @@ class CanvasTileLayerRenderer extends CanvasLayerRenderer {
       return;
     }
     const uid = getUid(this);
-    const alpha = opacity * (transition ? tile.getAlpha(uid, frameState.time) : 1);
+    const tileAlpha = transition ? tile.getAlpha(uid, frameState.time) : 1;
+    const alpha = opacity * tileAlpha;
     const alphaChanged = alpha !== this.context.globalAlpha;
     if (alphaChanged) {
       this.context.save();
@@ -389,7 +390,7 @@ class CanvasTileLayerRenderer extends CanvasLayerRenderer {
     if (alphaChanged) {
       this.context.restore();
     }
-    if (alpha !== 1) {
+    if (tileAlpha !== 1) {
       frameState.animate = true;
     } else if (transition) {
       tile.endTransition(uid);
diff --git a/test/spec/ol/layer/tile.test.js b/test/spec/ol/layer/tile.test.js
index caac548aca..a3a570aab8 100644
--- a/test/spec/ol/layer/tile.test.js
+++ b/test/spec/ol/layer/tile.test.js
@@ -1,5 +1,6 @@
+import {Map, View} from '../../../../src/ol/index.js';
 import TileLayer from '../../../../src/ol/layer/Tile.js';
-import OSM from '../../../../src/ol/source/OSM.js';
+import {OSM, XYZ} from '../../../../src/ol/source.js';
 
 
 describe('ol.layer.Tile', function() {
@@ -32,4 +33,73 @@ describe('ol.layer.Tile', function() {
 
   });
 
+  describe('frameState.animate after tile transition with layer opacity', function() {
+    let target, map;
+
+    beforeEach(function(done) {
+      target = document.createElement('div');
+      Object.assign(target.style, {
+        position: 'absolute',
+        left: '-1000px',
+        top: '-1000px',
+        width: '256px',
+        height: '256px'
+      });
+      document.body.appendChild(target);
+
+      map = new Map({
+        target: target,
+        view: new View({center: [0, 0], zoom: 1})
+      });
+
+      map.once('rendercomplete', function() {
+        done();
+      });
+    });
+
+    afterEach(function() {
+      map.dispose();
+      document.body.removeChild(target);
+    });
+
+    it('sets frameState.animate to false when opacity is 1', function(done) {
+      let lastFrameState;
+      const layer = new TileLayer({
+        opacity: 1,
+        source: new XYZ({
+          url: 'spec/ol/data/osm-0-0-0.png'
+        })
+      });
+      layer.on('postrender', function(event) {
+        lastFrameState = event.frameState;
+      });
+
+      map.once('rendercomplete', function() {
+        expect(lastFrameState.animate).to.be(false);
+        done();
+      });
+
+      map.addLayer(layer);
+    });
+
+    it('sets frameState.animate to false when opacity is 0.5', function(done) {
+      let lastFrameState;
+      const layer = new TileLayer({
+        opacity: 0.5,
+        source: new XYZ({
+          url: 'spec/ol/data/osm-0-0-0.png'
+        })
+      });
+      layer.on('postrender', function(event) {
+        lastFrameState = event.frameState;
+      });
+
+      map.once('rendercomplete', function() {
+        expect(lastFrameState.animate).to.be(false);
+        done();
+      });
+
+      map.addLayer(layer);
+    });
+  });
 });
diff --git a/test/spec/ol/map.test.js b/test/spec/ol/map.test.js
index 28b401494a..1d97f486cc 100644
--- a/test/spec/ol/map.test.js
+++ b/test/spec/ol/map.test.js
@@ -203,6 +203,7 @@ describe('ol.Map', function() {
         target: target,
         layers: [
           new TileLayer({
+            opacity: 0.5,
             source: new XYZ({
               url: 'spec/ol/data/osm-{z}-{x}-{y}.png'
             })