From ac541432000c24fee20cf0e0ce0881aa6437455a Mon Sep 17 00:00:00 2001
From: Andrew Dolgov <fox@madoka.spb.ru>
Date: Thu, 9 Aug 2007 08:36:04 +0100
Subject: [PATCH] infinite scrolling

---
 feedlist.js   | 28 ++++++++++++++++++++++++++--
 functions.php | 37 +++++++++++++++++++++----------------
 viewfeed.js   | 49 ++++++++++++++++++++++++++++++++++++++++++++-----
 3 files changed, 91 insertions(+), 23 deletions(-)

diff --git a/feedlist.js b/feedlist.js
index ac852e9e..66b040f9 100644
--- a/feedlist.js
+++ b/feedlist.js
@@ -1,5 +1,7 @@
 //var xmlhttp = Ajax.getTransport();
 
+var feed_cur_page = 0;
+
 function viewCategory(cat) {
 	active_feed_is_cat = true;
 	viewfeed(cat, '', true);
@@ -35,13 +37,35 @@ function viewFeedGoPage(i) {
 	}
 }
 
+
+function viewNextFeedPage() {
+	try {
+		if (!getActiveFeedId()) return;
+
+		feed_cur_page++;
+
+		viewfeed(getActiveFeedId(), undefined, undefined, undefined,
+			undefined, feed_cur_page);
+
+	} catch (e) {
+		exception_error(e, "viewFeedGoPage");
+	}
+}
+
 function viewfeed(feed, subop, is_cat, subop_param, skip_history, offset) {
 	try {
 
-		//if (!offset) page_offset = 0;
+//		if (!offset) page_offset = 0;
 
-		if (offset != undefined) {
+		if (offset > 0) {
 			page_offset = offset;
+		} else {
+			page_offset = 0;
+			feed_cur_page = 0;
+		}
+
+		if (getActiveFeedId() != feed) {
+			feed_cur_page = 0;
 		}
 
 		enableHotkeys();
diff --git a/functions.php b/functions.php
index 3bf2a0b7..7ca93956 100644
--- a/functions.php
+++ b/functions.php
@@ -3693,7 +3693,9 @@
 
 		$topmost_article_ids = array();
 
-		if (!$offset) $offset = 0;
+		if (!$offset) {
+			$offset = 0;
+		}
 
 		if ($subop == "undefined") $subop = "";
 
@@ -3777,24 +3779,26 @@
 		
 		/// STOP //////////////////////////////////////////////////////////////////////////////////
 
-		print "<div id=\"headlinesContainer\" $rtl_tag>";
+		if (!$offset) {
+			print "<div id=\"headlinesContainer\" $rtl_tag>";
 
-		if (!$result) {
-			print "<div align='center'>".__("Could not display feed (query failed). Please check label match syntax or local configuration.")."</div>";
-			return;
-		}
+			if (!$result) {
+				print "<div align='center'>".__("Could not display feed (query failed). Please check label match syntax or local configuration.")."</div>";
+				return;
+			}
 
-		print_headline_subtoolbar($link, $feed_site_url, $feed_title, false, 
-			$rtl_content, $feed, $cat_view, $search, $match_on, $search_mode, 
-			$offset, $limit);
+			print_headline_subtoolbar($link, $feed_site_url, $feed_title, false, 
+				$rtl_content, $feed, $cat_view, $search, $match_on, $search_mode, 
+				$offset, $limit);
 
-		print "<div id=\"headlinesInnerContainer\">";
+			print "<div id=\"headlinesInnerContainer\" onscroll=\"headlines_scroll_handler()\">";
+		}
 
 		if (db_num_rows($result) > 0) {
 
 #			print "\{$offset}";
 
-			if (!get_pref($link, 'COMBINED_DISPLAY_MODE')) {
+			if (!get_pref($link, 'COMBINED_DISPLAY_MODE') && !$offset) {
 				print "<table class=\"headlinesList\" id=\"headlinesList\" 
 					cellspacing=\"0\">";
 			}
@@ -3975,7 +3979,7 @@
 				++$lnum;
 			}
 
-			if (!get_pref($link, 'COMBINED_DISPLAY_MODE')) {			
+			if (!get_pref($link, 'COMBINED_DISPLAY_MODE') && !$offset) {			
 				print "</table>";
 			}
 
@@ -3984,12 +3988,13 @@
 
 
 		} else {
-			print "<div class='whiteBox'>".__('No articles found.')."</div>";
+			if (!$offset) print "<div class='whiteBox'>".__('No articles found.')."</div>";
 		}
 
-		print "</div>";
-
-		print "</div>";
+		if (!$offset) {
+			print "</div>";
+			print "</div>";
+		}
 
 		return $topmost_article_ids;
 	}
diff --git a/viewfeed.js b/viewfeed.js
index 1a3d775f..e464f219 100644
--- a/viewfeed.js
+++ b/viewfeed.js
@@ -38,7 +38,10 @@ function headlines_callback() {
 		debug("headlines_callback");
 		var f = document.getElementById("headlines-frame");
 		try {
-			f.scrollTop = 0;
+			if (feed_cur_page == 0) { 
+				debug("resetting headlines scrollTop");
+				f.scrollTop = 0; 
+			}
 		} catch (e) { };
 
 		if (xmlhttp.responseXML) {
@@ -47,11 +50,29 @@ function headlines_callback() {
 			var articles = xmlhttp.responseXML.getElementsByTagName("article");
 			var runtime_info = xmlhttp.responseXML.getElementsByTagName("runtime-info");
 
-			if (headlines) {
-				f.innerHTML = headlines.firstChild.nodeValue;
+			if (feed_cur_page == 0) {
+				if (headlines) {
+					f.innerHTML = headlines.firstChild.nodeValue;
+				} else {
+					debug("headlines_callback: returned no data");
+				f.innerHTML = "<div class='whiteBox'>" + __('Could not update headlines (missing XML data)') + "</div>";
+	
+				}
 			} else {
-				debug("headlines_callback: returned no data");
-			f.innerHTML = "<div class='whiteBox'>" + __('Could not update headlines (missing XML data)') + "</div>";
+				if (headlines) {
+					debug("adding some more headlines...");
+
+					var c = document.getElementById("headlinesList");
+
+					if (!c) {
+						c = document.getElementById("headlinesInnerContainer");
+					}
+
+					c.innerHTML = c.innerHTML + headlines.firstChild.nodeValue;
+				} else {
+					debug("headlines_callback: returned no data");
+					notify_error("Error while trying to load more headlines");	
+				}
 
 			}
 
@@ -103,6 +124,8 @@ function headlines_callback() {
 			try {
 				document.getElementById("headlinesInnerContainer").scrollTop = _tag_cdm_scroll;
 				_tag_cdm_scroll = false;
+				debug("resetting headlinesInner scrollTop");
+
 			} catch (e) { }
 		}
 
@@ -937,3 +960,19 @@ function cdmMouseIn(elem) {
 function cdmMouseOut(elem) {
 	active_post_id = false;
 }
+
+function headlines_scroll_handler() {
+	try {
+
+		var e = document.getElementById("headlinesInnerContainer");
+
+		if (e.scrollTop + e.offsetHeight == e.scrollHeight) {
+			debug("more cowbell!");
+
+			viewNextFeedPage();
+		}
+
+	} catch (e) {
+		exception_error("headlines_scroll_handler", e);
+	}
+}
-- 
2.39.2