From 3562824db7dc078853bf6da6023d06f68956358e Mon Sep 17 00:00:00 2001
From: Xiaoji Chen <xiaoji@uber.com>
Date: Tue, 31 Dec 2019 20:06:26 -0800
Subject: [PATCH] clean up picking code

---
 modules/core/src/lib/deck-picker.js       | 11 ++++----
 modules/core/src/lib/deck.js              | 24 +++++++++++------
 modules/core/src/lib/picking/pick-info.js | 32 -----------------------
 3 files changed, 21 insertions(+), 46 deletions(-)

diff --git a/modules/core/src/lib/deck-picker.js b/modules/core/src/lib/deck-picker.js
index 95835c2a81d..7d483094f84 100644
--- a/modules/core/src/lib/deck-picker.js
+++ b/modules/core/src/lib/deck-picker.js
@@ -30,7 +30,7 @@ import GL from '@luma.gl/constants';
 import assert from '../utils/assert';
 import PickLayersPass from '../passes/pick-layers-pass';
 import {getClosestObject, getUniqueObjects} from './picking/query-object';
-import {processPickInfo, callLayerPickingCallbacks, getLayerPickingInfo} from './picking/pick-info';
+import {processPickInfo, getLayerPickingInfo} from './picking/pick-info';
 
 export default class DeckPicker {
   constructor(gl) {
@@ -125,7 +125,6 @@ export default class DeckPicker {
     radius = 0,
     depth = 1,
     mode = 'query',
-    event,
     unproject3D,
     onViewportActive
   }) {
@@ -213,10 +212,10 @@ export default class DeckPicker {
         pixelRatio
       });
 
-      const processedPickInfos = callLayerPickingCallbacks(infos, mode, event);
-
-      if (processedPickInfos) {
-        processedPickInfos.forEach(info => result.push(info));
+      for (const info of infos.values()) {
+        if (info.layer) {
+          result.push(info);
+        }
       }
 
       // If no object is picked stop.
diff --git a/modules/core/src/lib/deck.js b/modules/core/src/lib/deck.js
index 6a989543d83..e6c99be32ba 100644
--- a/modules/core/src/lib/deck.js
+++ b/modules/core/src/lib/deck.js
@@ -532,7 +532,6 @@ export default class Deck {
       this.layerManager.context.mousePosition = {x: _pickRequest.x, y: _pickRequest.y};
     }
 
-    _pickRequest.callback = this.props.onHover;
     _pickRequest.event = event;
     _pickRequest.mode = 'hover';
   }
@@ -541,19 +540,28 @@ export default class Deck {
   _pickAndCallback() {
     const {_pickRequest} = this;
 
-    if (_pickRequest.mode) {
-      // perform picking
+    if (_pickRequest.event) {
+      // Perform picking
       const {result, emptyInfo} = this._pick('pickObject', 'pickObject Time', _pickRequest);
-      const shouldGenerateInfo = _pickRequest.callback || this.props.getTooltip;
-      const pickedInfo = shouldGenerateInfo && (result.find(info => info.index >= 0) || emptyInfo);
+      const pickedInfo = result[0] || emptyInfo;
+
+      // Update tooltip
       if (this.props.getTooltip) {
         const displayInfo = this.props.getTooltip(pickedInfo);
         this.tooltip.setTooltip(displayInfo, pickedInfo.x, pickedInfo.y);
       }
-      if (_pickRequest.callback && !pickedInfo.handled) {
-        _pickRequest.callback(pickedInfo, _pickRequest.event);
+
+      // Execute callbacks
+      let handled = false;
+      if (pickedInfo.layer) {
+        handled = pickedInfo.layer.onHover(pickedInfo, _pickRequest.event);
+      }
+      if (!handled && this.props.onHover) {
+        this.props.onHover(pickedInfo, _pickRequest.event);
       }
-      _pickRequest.mode = null;
+
+      // Clear pending pickRequest
+      _pickRequest.event = null;
     }
   }
 
diff --git a/modules/core/src/lib/picking/pick-info.js b/modules/core/src/lib/picking/pick-info.js
index 4b9a7368d6e..60e86f1a8f5 100644
--- a/modules/core/src/lib/picking/pick-info.js
+++ b/modules/core/src/lib/picking/pick-info.js
@@ -149,35 +149,3 @@ function getViewportFromCoordinates({viewports}) {
   const viewport = viewports[0];
   return viewport;
 }
-
-// Per-layer event handlers (e.g. onClick, onHover) are provided by the
-// user and out of deck.gl's control. It's very much possible that
-// the user calls React lifecycle methods in these function, such as
-// ReactComponent.setState(). React lifecycle methods sometimes induce
-// a re-render and re-generation of props of deck.gl and its layers,
-// which invalidates all layers currently passed to this very function.
-
-// Therefore, per-layer event handlers must be invoked at the end
-// of the picking operation. NO operation that relies on the states of current
-// layers should be called after this code.
-export function callLayerPickingCallbacks(infos, mode, event) {
-  const unhandledPickInfos = [];
-
-  infos.forEach(info => {
-    if (!info.layer) {
-      return;
-    }
-
-    switch (mode) {
-      case 'hover':
-        info.handled = info.layer.onHover(info, event);
-        break;
-      case 'query':
-      default:
-    }
-
-    unhandledPickInfos.push(info);
-  });
-
-  return unhandledPickInfos;
-}