From 77e9f0819e5495467e72e17a48e3f0b724034057 Mon Sep 17 00:00:00 2001
From: "Alex A. Naanou" <alex.nanou@gmail.com>
Date: Mon, 21 Nov 2022 03:04:48 +0300
Subject: [PATCH] added scroll position to nav history...

Signed-off-by: Alex A. Naanou <alex.nanou@gmail.com>
---
 pwiki2.html | 35 +++++++++++++++++++++++++++++++----
 pwiki2.js   |  6 ++++--
 2 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/pwiki2.html b/pwiki2.html
index de1a8cf..32dc9cd 100755
--- a/pwiki2.html
+++ b/pwiki2.html
@@ -375,6 +375,29 @@ require(['./browser'], function(browser){
 		// NOTE: this seems not to work if the REFRESH_DELAY is too small...
 		setTimeout(function(){
 			pwiki.location = [path, hash] }, REFRESH_DELAY) })
+
+	// scroll...
+	// NOTE: we restore scroll position only on history navigation...
+	var save_scroll = function(){ 
+		history.replaceState(
+			{ 
+				path: pwiki.location,
+				// XXX HACK this will work only on full page...
+				scroll: document.scrollingElement.scrollTop,
+			}, 
+			'',
+			// XXX 
+			window.location.hash) }
+	// save scroll position just after scroll is done...
+	var scrolling
+	window.addEventListener('scroll', function(evt){
+		scrolling
+			&& clearTimeout(scrolling)
+		scrolling = setTimeout(save_scroll, 200) })
+	// get scroll position from history state...
+	window.addEventListener('popstate', function(evt){
+		pwiki.__scroll = (evt.state ?? {}).scroll })
+
 	pwiki
 		.onBeforeNavigate(function(){
 			saveAll() })
@@ -382,7 +405,7 @@ require(['./browser'], function(browser){
 			// NOTE: we do not need to directly update location.hash here as
 			//		that will push an extra history item...
 			history.replaceState(
-				{path: this.location}, 
+				{ path: this.location }, 
 				'',
 				'#'+this.location 
 					+(this.hash ? 
@@ -416,11 +439,15 @@ require(['./browser'], function(browser){
 				`${titles.length > 1 ? 
 					titles.at(-1).innerText
 					: this.title} &mdash; pWiki`
-			// scroll to anchor element...
-			this.hash
-				&& this.dom
+			// scroll...
+			this.hash ?
+				// to anchor element...
+				this.dom
 					.querySelector('#'+ this.hash)
 					.scrollIntoView() 
+				// restore history position...
+				// XXX HACK this will work only on full page...
+				: (document.scrollingElement.scrollTop = this.__scroll ?? 0)
 
 			// XXX MediumEditor...
 			//setupMediumEditor()
diff --git a/pwiki2.js b/pwiki2.js
index dabff9c..f27537f 100755
--- a/pwiki2.js
+++ b/pwiki2.js
@@ -36,8 +36,6 @@
 * 		- 
 *
 *
-* XXX load new page at .scrollTop = 0 if no anchors are given...
-* 		...and/or remember scroll position per page...
 * XXX sort: define a generic sort path argument...
 * 		...this will unify all interfaces (macros/patterns/etc)
 * XXX macros: else/default macro args essentially mean the same thing, should we
@@ -51,6 +49,10 @@
 * 			await pwiki.parse('<macro src=../tags join=", ">@source(.)</macro>')
 *		This will not:
 * 			await pwiki.parse('<macro src="../tags" join=", ">@source(.)</macro>')
+* XXX FEATURE: make the pwiki "widget" work bot as an element and as a 
+* 		full page (current)...
+* 		...would need to handle stuff like history, url, nav locally...
+* 		see: pwiki2.html
 * XXX ASAP test: can we store the file handler with permissions in a ServiceWorker??
 * XXX macros: Q: do we need macros for printing errors and the like???
 * XXX the parser should handle all action return values, including: