From 5b6d65e1c97cbc252875142d6629b1a36515312a Mon Sep 17 00:00:00 2001
From: Nick Krecklow <hello@github.nklow.com>
Date: Fri, 12 Jun 2020 18:32:53 -0500
Subject: [PATCH] simplify isZoomed historical graph update logic

---
 assets/js/graph.js   | 40 ++++++++++------------------------------
 assets/js/plugins.js | 24 ------------------------
 2 files changed, 10 insertions(+), 54 deletions(-)

diff --git a/assets/js/graph.js b/assets/js/graph.js
index cb59959..a52557d 100644
--- a/assets/js/graph.js
+++ b/assets/js/graph.js
@@ -3,7 +3,7 @@ import uPlot from 'uplot'
 import { RelativeScale } from './scale'
 
 import { formatNumber, formatTimestampSeconds } from './util'
-import { uPlotTooltipPlugin, uPlotIsZoomedPlugin } from './plugins'
+import { uPlotTooltipPlugin } from './plugins'
 
 import { FAVORITE_SERVERS_STORAGE_KEY } from './favorites'
 
@@ -18,7 +18,6 @@ export class GraphDisplayManager {
     this._hasLoadedSettings = false
     this._initEventListenersOnce = false
     this._showOnlyFavorites = false
-    this._isPlotZoomed = false
   }
 
   addGraphPoint (timestamp, playerCounts) {
@@ -50,14 +49,14 @@ export class GraphDisplayManager {
       }
     }
 
-    // If not zoomed, paint updated data structure
-    // Otherwise flag the plot data as dirty with repainting to be handled by #handlePlotZoomOut
-    // This prevents #addGraphPoint calls from resetting the graph's zoom state
-    if (!this._isPlotZoomed) {
-      this._plotInstance.setData(this.getGraphData())
-    } else {
-      this._isPlotZoomedDataDirty = true
-    }
+    // Dedrive plotTimestamps from the uPlot instance's data since this._graphTimestamps has been mutated
+    const plotTimestamps = this._plotInstance.data[0]
+    const plotScaleX = this._plotInstance.scales.x
+
+    const isZoomed = plotScaleX.min > plotTimestamps[0] || plotScaleX.max < plotTimestamps[plotTimestamps.length - 1]
+
+    // Avoid redrawing the plot when zoomed
+    this._plotInstance.setData(this.getGraphData(), !isZoomed)
   }
 
   loadLocalStorage () {
@@ -251,8 +250,7 @@ export class GraphDisplayManager {
           } else {
             this._app.tooltip.hide()
           }
-        }),
-        uPlotIsZoomedPlugin(this.handlePlotZoomIn, this.handlePlotZoomOut)
+        })
       ],
       ...this.getPlotSize(),
       cursor: {
@@ -347,21 +345,6 @@ export class GraphDisplayManager {
     this._resizeRequestTimeout = undefined
   }
 
-  handlePlotZoomIn = () => {
-    this._isPlotZoomed = true
-  }
-
-  handlePlotZoomOut = () => {
-    this._isPlotZoomed = false
-
-    // Test if the data has changed while the plot was zoomed in
-    if (this._isPlotZoomedDataDirty) {
-      this._isPlotZoomedDataDirty = false
-
-      this._plotInstance.setData(this.getGraphData())
-    }
-  }
-
   initEventListeners () {
     if (!this._initEventListenersOnce) {
       this._initEventListenersOnce = true
@@ -469,9 +452,6 @@ export class GraphDisplayManager {
     this._graphData = []
     this._hasLoadedSettings = false
 
-    this._isPlotZoomed = false
-    this._isPlotZoomedDataDirty = false
-
     // Fire #clearTimeout if the timeout is currently defined
     if (this._resizeRequestTimeout) {
       clearTimeout(this._resizeRequestTimeout)
diff --git a/assets/js/plugins.js b/assets/js/plugins.js
index 1027d61..0595d7d 100644
--- a/assets/js/plugins.js
+++ b/assets/js/plugins.js
@@ -26,27 +26,3 @@ export function uPlotTooltipPlugin (onHover) {
     }
   }
 }
-
-export function uPlotIsZoomedPlugin (onZoomIn, onZoomOut) {
-  return {
-    hooks: {
-      setSelect: u => {
-        u._zoomPluginIgnoreNextSetScale = true
-
-        if (onZoomIn) {
-          onZoomIn(u)
-        }
-      },
-      setScale: u => {
-        if (typeof u._zoomPluginIgnoreNextSetScale !== 'boolean') {
-          return
-        }
-        if (u._zoomPluginIgnoreNextSetScale) {
-          u._zoomPluginIgnoreNextSetScale = false
-        } else if (onZoomOut) {
-          onZoomOut(u)
-        }
-      }
-    }
-  }
-}