From f67baa0dc0b784337881a37c2b580c8f55465ddb Mon Sep 17 00:00:00 2001
From: Olivier Guyot <olivier.guyot@camptocamp.com>
Date: Fri, 22 Feb 2019 15:00:57 +0100
Subject: [PATCH] Interactions / fix zoom level when a zoom interaction ends

---
 src/ol/interaction/DragRotateAndZoom.js |  2 +-
 src/ol/interaction/MouseWheelZoom.js    | 18 +++++++++++++-----
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/src/ol/interaction/DragRotateAndZoom.js b/src/ol/interaction/DragRotateAndZoom.js
index 2a43740c03..3e750df327 100644
--- a/src/ol/interaction/DragRotateAndZoom.js
+++ b/src/ol/interaction/DragRotateAndZoom.js
@@ -109,7 +109,7 @@ class DragRotateAndZoom extends PointerInteraction {
 
     const map = mapBrowserEvent.map;
     const view = map.getView();
-    const direction = this.lastScaleDelta_ - 1;
+    const direction = this.lastScaleDelta_ > 1 ? 1 : -1;
     view.endInteraction(this.duration_, direction);
     this.lastScaleDelta_ = 0;
     return false;
diff --git a/src/ol/interaction/MouseWheelZoom.js b/src/ol/interaction/MouseWheelZoom.js
index a08e657956..30548d2587 100644
--- a/src/ol/interaction/MouseWheelZoom.js
+++ b/src/ol/interaction/MouseWheelZoom.js
@@ -57,7 +57,13 @@ class MouseWheelZoom extends Interaction {
      * @private
      * @type {number}
      */
-    this.delta_ = 0;
+    this.totalDelta_ = 0;
+
+    /**
+     * @private
+     * @type {number}
+     */
+    this.lastDelta_ = 0;
 
     /**
      * @private
@@ -134,7 +140,7 @@ class MouseWheelZoom extends Interaction {
   endInteraction_() {
     this.trackpadTimeoutId_ = undefined;
     const view = this.getMap().getView();
-    view.endInteraction();
+    view.endInteraction(undefined, Math.sign(this.lastDelta_), this.lastAnchor_);
   }
 
   /**
@@ -181,6 +187,8 @@ class MouseWheelZoom extends Interaction {
 
     if (delta === 0) {
       return false;
+    } else {
+      this.lastDelta_ = delta;
     }
 
     const now = Date.now();
@@ -208,7 +216,7 @@ class MouseWheelZoom extends Interaction {
       return false;
     }
 
-    this.delta_ += delta;
+    this.totalDelta_ += delta;
 
     const timeLeft = Math.max(this.timeout_ - (now - this.startTime_), 0);
 
@@ -228,10 +236,10 @@ class MouseWheelZoom extends Interaction {
       view.cancelAnimations();
     }
     const maxDelta = MAX_DELTA;
-    const delta = clamp(this.delta_, -maxDelta, maxDelta);
+    const delta = clamp(this.totalDelta_, -maxDelta, maxDelta);
     zoomByDelta(view, -delta, this.lastAnchor_, this.duration_);
     this.mode_ = undefined;
-    this.delta_ = 0;
+    this.totalDelta_ = 0;
     this.lastAnchor_ = null;
     this.startTime_ = undefined;
     this.timeoutId_ = undefined;