fix some flakiness in scrolling the cursor into view

codemirror · Feb 19, 2011 · cac102d · cac102d
1 parent 1be1773
commit cac102d
Showing 1 changed file with 14 additions and 8 deletions.
diff --git a/lib/codemirror.js b/lib/codemirror.js
@@ -364,8 +364,8 @@ var CodeMirror = (function() {
            '<span>xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx</span></pre>' +
         '<div style="position: relative">' +
           '<div class="CodeMirror-gutter"><div class="CodeMirror-gutter-text"></div></div>' +
-          '<div style="overflow: hidden; position: absolute; width: 0">' +
-            '<textarea style="position: absolute; width: 10000px;"></textarea></div>' +
+          '<div style="overflow: hidden; position: absolute; width: 0; left: 0;">' +
+            '<textarea style="width: 10000px; height: 1px; position: absolute;"></textarea></div>' +
           '<div class="CodeMirror-lines"><div style="position: relative">' +
             '<pre class="CodeMirror-cursor">&nbsp;</pre>' +
             '<div></div></div></div></div></div>';
@@ -740,21 +740,25 @@ var CodeMirror = (function() {
 
     function scrollCursorIntoView() {
       var cursor = localCoords(sel.inverted ? sel.from : sel.to);
-      cursor.x += paddingLeft(); cursor.y += paddingTop();
-      scrollIntoView(cursor.x, cursor.y, cursor.x, cursor.yBot);
+      return scrollIntoView(cursor.x, cursor.y, cursor.x, cursor.yBot);
     }
     function scrollIntoView(x1, y1, x2, y2) {
+      var pl = paddingLeft(), pt = paddingTop();
+      y1 += pt; y2 += pt; x1 += pl; x2 += pl;
       var screen = div.clientHeight, screentop = div.scrollTop;
       if (y1 < screentop)
         div.scrollTop = Math.max(0, y1 - 10);
       else if (y2 > screentop + screen)
         div.scrollTop = y2 + 10 - screen;
 
-      var screenw = div.offsetWidth, screenleft = div.scrollLeft;
+      var screenw = div.clientWidth, screenleft = div.scrollLeft;
       if (x1 < screenleft)
         div.scrollLeft = Math.max(0, x1 - 10);
-      else if (x2 > screenw + screenleft)
+      else if (x2 > screenw + screenleft) {
         div.scrollLeft = x2 + 10 - screenw;
+        if (x2 > code.clientWidth) return false;
+      }
+      return true;
     }
 
     function visibleLines() {
@@ -949,7 +953,7 @@ var CodeMirror = (function() {
     function updateCursor() {
       var head = sel.inverted ? sel.from : sel.to;
       var x = charX(head.line, head.ch) + "px", y = (head.line - showingFrom) * lineHeight() + "px";
-      inputDiv.style.top = y; inputDiv.style.left = x;
+      inputDiv.style.top = y;
       if (posEq(sel.from, sel.to)) {
         cursor.style.top = y; cursor.style.left = x;
         cursor.style.display = "";
@@ -1317,9 +1321,11 @@ var CodeMirror = (function() {
       updateInput = null; changes = []; textChanged = false; selectionChanged = false;
     }
     function endOperation() {
-      if (selectionChanged) scrollCursorIntoView();
+      var reScroll = false;
+      if (selectionChanged) reScroll = !scrollCursorIntoView();
       if (changes.length) updateDisplay(changes);
       else if (selectionChanged) updateCursor();
+      if (reScroll) scrollCursorIntoView();
       if (selectionChanged) restartBlink();
 
       if (updateInput === true || (updateInput !== false && selectionChanged))