# HG changeset patch
# User Alexander Plavin <alexander@plav.in>
# Date 1379529852 -14400
# Node ID 9ad7dd9574a91cca6a84d26e29cd146005478e79
# Parent  22a70f31e3e9fff19381a998665908dfe30e646a
hgweb: add ajaxScrollInit function, which does the ajax requests and processing

This function should be correctly called on a page, otherwise there is
no effect.
When called, it makes ajax requests for the next portion of changesets when the
user scrolls to the end. Also, when the monitor is high so that the
default amount of changesets isn't enough to fill it, multiple portions are
loaded if needed after the page load.

diff -r 22a70f31e3e9 -r 9ad7dd9574a9 mercurial/templates/static/mercurial.js
--- a/mercurial/templates/static/mercurial.js	Wed Sep 18 14:36:19 2013 -0500
+++ b/mercurial/templates/static/mercurial.js	Wed Sep 18 22:44:12 2013 +0400
@@ -345,3 +345,61 @@
 function appendFormatHTML(element, formatStr, replacements) {
     element.insertAdjacentHTML('beforeend', format(formatStr, replacements));
 }
+
+function ajaxScrollInit(urlFormat,
+                        nextHash,
+                        nextHashRegex,
+                        containerSelector,
+                        messageFormat) {
+    updateInitiated = false;
+    container = document.querySelector(containerSelector);
+
+    function scrollHandler() {
+        if (updateInitiated) {
+            return;
+        }
+
+        var scrollHeight = document.documentElement.scrollHeight;
+        var clientHeight = document.documentElement.clientHeight;
+        var scrollTop = document.body.scrollTop
+            || document.documentElement.scrollTop;
+
+        if (scrollHeight - (scrollTop + clientHeight) < 50) {
+            updateInitiated = true;
+
+            if (!nextHash) {
+                return;
+            }
+
+            makeRequest(
+                format(urlFormat, {hash: nextHash}),
+                'GET',
+                function onstart() {
+                },
+                function onsuccess(htmlText) {
+                    var m = htmlText.match(nextHashRegex);
+                    nextHash = m ? m[1] : null;
+
+                    var doc = docFromHTML(htmlText);
+                    var nodes = doc.querySelector(containerSelector).children;
+                    while (nodes.length) {
+                        var node = nodes[0];
+                        node = document.adoptNode(node);
+                        container.appendChild(node);
+                    }
+                    process_dates();
+                },
+                function onerror(errorText) {
+                },
+                function oncomplete() {
+                    updateInitiated = false;
+                    scrollHandler();
+                }
+            );
+        }
+    }
+
+    window.addEventListener('scroll', scrollHandler);
+    window.addEventListener('resize', scrollHandler);
+    scrollHandler();
+}