From bc9beb1e8714fec03e91b5d7710fc23383ec0e26 Mon Sep 17 00:00:00 2001
From: daboe01 <daboe01@googlemail.com>
Date: Fri, 27 May 2016 21:24:30 +0200
Subject: [PATCH] new: render to dom only the visible stuff

---
 AppKit/CPTextView/CPLayoutManager.j | 28 ++++++----
 AppKit/CPTextView/CPTextView.j      | 83 +++++++++++++++++++++++++++++
 2 files changed, 100 insertions(+), 11 deletions(-)

diff --git a/AppKit/CPTextView/CPLayoutManager.j b/AppKit/CPTextView/CPLayoutManager.j
index 1d1d78de0..387e0fcbb 100644
--- a/AppKit/CPTextView/CPLayoutManager.j
+++ b/AppKit/CPTextView/CPLayoutManager.j
@@ -1170,6 +1170,7 @@ var _objectsInRange = function(aList, aRange)
             var color = [attributes objectForKey:CPForegroundColorAttributeName],
                 elem = [self createDOMElementWithText:string andFont:font andColor:color],
                 run = {_range:CPMakeRangeCopy(effectiveRange), elem:elem, string:string};
+                run = {_range:CPMakeRangeCopy(effectiveRange), color:color, font:font, elem:nil, string:string};
 
             _runs.push(run);
         }
@@ -1257,7 +1258,12 @@ var _objectsInRange = function(aList, aRange)
     {
         var run = runs[i];
 
-        if (run.DOMactive && !run.DOMpatched || !run.elem)
+        if (!run.elem && CPRectIntersectsRect([_textContainer._textView exposedRect], _fragmentRect))
+        {
+            run.elem=[self createDOMElementWithText:run.string andFont:run.font andColor:run.color];
+        }
+
+        if (run.DOMactive && !run.DOMpatched)
             continue;
 
         if (!_glyphsFrames)
@@ -1267,19 +1273,19 @@ var _objectsInRange = function(aList, aRange)
         orig.x = _glyphsFrames[loc].origin.x + aPoint.x;
         orig.y = _glyphsFrames[loc].origin.y + aPoint.y + _glyphsOffsets[loc];
 
-        run.elem.style.left = (orig.x) + "px";
-        run.elem.style.top = (orig.y) + "px";
+        if(run.elem)
+        {
+            run.elem.style.left = (orig.x) + "px";
+            run.elem.style.top = (orig.y) + "px";
 
-        if (!run.DOMactive)
-            _textContainer._textView._DOMElement.appendChild(run.elem);
+            if (!run.DOMactive)
+                _textContainer._textView._DOMElement.appendChild(run.elem);
+
+            run.DOMactive = YES;
+        }
 
-        run.DOMactive = YES;
         run.DOMpatched = NO;
 
-        if (run.underline)
-        {
-            // <!> FIXME
-        }
     }
 }
 
@@ -1324,7 +1330,7 @@ var _objectsInRange = function(aList, aRange)
     {
         _runs[i]._range.location += rangeOffset;
 
-        if (verticalOffset)
+        if (verticalOffset && _runs[i].elem)
         {
             _runs[i].elem.top = (_runs[i].elem.top + verticalOffset) + 'px';
             _runs[i].DOMpatched = YES;
diff --git a/AppKit/CPTextView/CPTextView.j b/AppKit/CPTextView/CPTextView.j
index 064eacaab..e6c009c63 100644
--- a/AppKit/CPTextView/CPTextView.j
+++ b/AppKit/CPTextView/CPTextView.j
@@ -138,6 +138,9 @@ var kDelegateRespondsTo_textShouldBeginEditing
     int                         _stickyXLocation;
 
     CPArray                     _selectionSpans;
+    CPView                      _observedClipView;
+    CGRect                      _exposedRect;
+
     CPTimer                     _scrollingTimer;
 }
 
@@ -248,6 +251,86 @@ var kDelegateRespondsTo_textShouldBeginEditing
 
     [super _addObservers];
     [self _setObserveWindowKeyNotifications:YES];
+    [self _startObservingClipView];
+}
+- (void)_startObservingClipView
+{
+    if (!_observedClipView)
+        return;
+
+    var defaultCenter = [CPNotificationCenter defaultCenter];
+
+    [_observedClipView setPostsFrameChangedNotifications:YES];
+    [_observedClipView setPostsBoundsChangedNotifications:YES];
+
+    [defaultCenter addObserver:self
+                      selector:@selector(superviewFrameChanged:)
+                          name:CPViewFrameDidChangeNotification
+                        object:_observedClipView];
+
+    [defaultCenter addObserver:self
+                      selector:@selector(superviewBoundsChanged:)
+                          name:CPViewBoundsDidChangeNotification
+                        object:_observedClipView];
+}
+- (CGRect)exposedRect
+{
+    if (!_exposedRect)
+    {
+        var superview = [self superview];
+
+        if ([superview isKindOfClass:[CPClipView class]])
+            _exposedRect = [superview bounds];
+        else
+            _exposedRect = [self bounds];
+    }
+
+    return _exposedRect;
+}
+
+/*!
+    @ignore
+*/
+- (void)superviewBoundsChanged:(CPNotification)aNotification
+{
+    _exposedRect = nil;
+    [self setNeedsDisplay:YES];
+}
+
+/*!
+    @ignore
+*/
+- (void)superviewFrameChanged:(CPNotification)aNotification
+{
+    _exposedRect = nil;
+}
+
+- (void)viewWillMoveToSuperview:(CPView)aView
+{
+    if ([aView isKindOfClass:[CPClipView class]])
+        _observedClipView = aView;
+    else
+        [self _stopObservingClipView];
+
+    [super viewWillMoveToSuperview:aView];
+}
+
+- (void)_stopObservingClipView
+{
+    if (!_observedClipView)
+        return;
+
+    var defaultCenter = [CPNotificationCenter defaultCenter];
+
+    [defaultCenter removeObserver:self
+                             name:CPViewFrameDidChangeNotification
+                           object:_observedClipView];
+
+    [defaultCenter removeObserver:self
+                             name:CPViewBoundsDidChangeNotification
+                           object:_observedClipView];
+
+    _observedClipView = nil;
 }
 
 - (void)_windowDidResignKey:(CPNotification)aNotification