From 32321e381cead34f231724120ea834bb2320c69b Mon Sep 17 00:00:00 2001
From: Olivier Guyot <olivier.guyot@camptocamp.com>
Date: Thu, 2 Apr 2020 14:14:40 +0200
Subject: [PATCH] View / avoid solving constraints related to map size change
 during anim

---
 src/ol/PluggableMap.js    |  2 +-
 src/ol/View.js            |  5 +++-
 test/spec/ol/view.test.js | 48 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/src/ol/PluggableMap.js b/src/ol/PluggableMap.js
index 792215e1cc..5cd3ad7f22 100644
--- a/src/ol/PluggableMap.js
+++ b/src/ol/PluggableMap.js
@@ -989,7 +989,7 @@ class PluggableMap extends BaseObject {
    * @private
    */
   handleSizeChanged_() {
-    if (this.getView()) {
+    if (this.getView() && !this.getView().getAnimating()) {
       this.getView().resolveConstraints(0);
     }
 
diff --git a/src/ol/View.js b/src/ol/View.js
index bcccad7e04..3d5be60121 100644
--- a/src/ol/View.js
+++ b/src/ol/View.js
@@ -762,11 +762,14 @@ class View extends BaseObject {
    * Stores the viewport size on the view. The viewport size is not read every time from the DOM
    * to avoid performance hit and layout reflow.
    * This should be done on map size change.
+   * Note: the constraints are not resolved during an animation to avoid stopping it
    * @param {import("./size.js").Size=} opt_size Viewport size; if undefined, [100, 100] is assumed
    */
   setViewportSize(opt_size) {
     this.viewportSize_ = Array.isArray(opt_size) ? opt_size.slice() : [100, 100];
-    this.resolveConstraints(0);
+    if (!this.getAnimating()) {
+      this.resolveConstraints(0);
+    }
   }
 
   /**
diff --git a/test/spec/ol/view.test.js b/test/spec/ol/view.test.js
index 3e186909e9..e10af8c0cb 100644
--- a/test/spec/ol/view.test.js
+++ b/test/spec/ol/view.test.js
@@ -1090,6 +1090,54 @@ describe('ol.View', function() {
 
     });
 
+    it('completes even though Map#setSize is called', function(done) {
+
+      const view = new View({
+        center: [0, 0],
+        zoom: 0
+      });
+      const map = new Map({
+        view
+      });
+      map.setSize([110, 90]);
+
+      view.animate({
+        zoom: 1,
+        duration: 25
+      }, function() {
+        expect(view.getZoom()).to.be(1);
+        done();
+      });
+
+      setTimeout(function() {
+        map.setSize([100, 100]);
+      }, 10);
+
+    });
+
+    it('completes even though Map#updateSize is called', function(done) {
+
+      const view = new View({
+        center: [0, 0],
+        zoom: 0
+      });
+      const map = new Map({
+        view
+      });
+
+      view.animate({
+        zoom: 1,
+        duration: 25
+      }, function() {
+        expect(view.getZoom()).to.be(1);
+        done();
+      });
+
+      setTimeout(function() {
+        map.updateSize();
+      }, 10);
+
+    });
   });
 
   describe('#cancelAnimations()', function() {