simplify scroll item to midpoint logic

mojavelinux · mojavelinux · commit a1b47e8ff588 · 2021-01-01T20:33:19.000-07:00
diff --git a/src/js/01-nav.js b/src/js/01-nav.js
@@ -151,11 +151,10 @@
   }
 
   function scrollItemToMidpoint (panel, item) {
-    var itemRect = item.getBoundingClientRect()
+    if (panel.scrollHeight === panel.clientHeight) return // not scrollable
     var panelRect = panel.getBoundingClientRect()
-    var currentOffsetTop = itemRect.top - panelRect.top + panel.scrollTop
-    var targetOffsetTop = (panelRect.height - itemRect.height) * 0.5
-    panel.scrollTop = Math.max(0, (currentOffsetTop - targetOffsetTop).toFixed())
+    var linkRect = item.getBoundingClientRect()
+    panel.scrollTop += Math.round(linkRect.top - panelRect.top - (panelRect.height - linkRect.height) * 0.5)
   }
 
   function find (from, selector) {

Original file line number	Diff line number	Diff line change
`@@ -151,11 +151,10 @@`
`151`	`151`	`}`
`152`	`152`
`153`	`153`	`function scrollItemToMidpoint (panel, item) {`
`154`		`- var itemRect = item.getBoundingClientRect()`
	`154`	`+ if (panel.scrollHeight === panel.clientHeight) return // not scrollable`
`155`	`155`	`var panelRect = panel.getBoundingClientRect()`
`156`		`- var currentOffsetTop = itemRect.top - panelRect.top + panel.scrollTop`
`157`		`- var targetOffsetTop = (panelRect.height - itemRect.height) * 0.5`
`158`		`- panel.scrollTop = Math.max(0, (currentOffsetTop - targetOffsetTop).toFixed())`
	`156`	`+ var linkRect = item.getBoundingClientRect()`
	`157`	`+ panel.scrollTop += Math.round(linkRect.top - panelRect.top - (panelRect.height - linkRect.height) * 0.5)`
`159`	`158`	`}`
`160`	`159`
`161`	`160`	`function find (from, selector) {`