Adds touch scroll.

wilkie · Apr 5, 2013 · e6837b4 · e6837b4
1 parent 50d567f
commit e6837b4
Showing 1 changed file with 29 additions and 6 deletions.
diff --git a/lib/gutenberg/assets/js/typeset.js b/lib/gutenberg/assets/js/typeset.js
@@ -116,9 +116,9 @@ function goto_page(page_number) {
   $('#page-' + next_page + ' .divider').show();
 }
 
-function scroll_up() {
+function scroll_up(amount) {
   page = $('#page-' + next_page);
-  page.css('height', '-=50');
+  page.css('height', '-=' + amount);
 
   if (page.height() <= 0) {
     if (next_page > 1) {
@@ -132,9 +132,9 @@ function scroll_up() {
   }
 }
 
-function scroll_down() {
+function scroll_down(amount) {
   page = $('#page-' + next_page);
-  page.css('height', '+=50');
+  page.css('height', '+=' + amount);
 
   if (page.height() > $(window).height()) {
     if (next_page > 1) {
@@ -369,12 +369,35 @@ $('body').on('swiperight', function(e) {
   goto_page(next_page);
 });
 
+var start_height;
+var start_pos;
+$('body').on('movestart', function(e) {
+  start_height = $('#page-' + next_page).height();
+  start_pos = e.startY;
+});
+
+$('body').on('move', function(e) {
+  // Calculate deltaY ourselves to increase accuracy
+  deltaY = e.pageY - start_pos;
+
+  var last_page = next_page;
+  if (deltaY > 0) {
+    scroll_down(deltaY);
+  }
+  else if (deltaY < 0) {
+    scroll_up(-deltaY);
+  }
+
+  start_pos = e.pageY;
+  start_height = $('#page-' + next_page).height();
+});
+
 $('body').mousewheel(function(event, delta, deltaX, deltaY) {
   if (deltaY > 0) {
-    scroll_up();
+    scroll_up(50);
   }
   else if (deltaY < 0) {
-    scroll_down();
+    scroll_down(50);
   }
 });