made the tableview handle hiding and showing of columns properly

AppKit/CPTableColumn.j

@@ -348,7 +348,14 @@ CPTableColumnUserResizingMask   = 1 << 1;
 
 - (void)setHidden:(BOOL)shouldBeHidden
 {
+    shouldBeHidden = !!shouldBeHidden
+    if (_isHidden === shouldBeHidden)
+        return;
+    
     _isHidden = shouldBeHidden;
+    
+    [[self headerView] setHidden:shouldBeHidden];
+    [[self tableView] _tableColumnVisibilityDidChange:self];
 }
 
 - (BOOL)isHidden

AppKit/CPTableHeaderView.j

@@ -187,21 +187,13 @@ var _CPTableColumnHeaderViewStringValueKey = @"_CPTableColumnHeaderViewStringVal
 
 - (CGRect)headerRectOfColumn:(int)aColumnIndex
 {
-    var tableColumns = [_tableView tableColumns];
-
-    if (aColumnIndex < 0 || aColumnIndex > [tableColumns count])
-        [CPException raise:"invalid" reason:"tried to get headerRectOfColumn: on invalid column"];
-
-    // UPDATE COLUMN RANGES ?
+    var headerRect = [self bounds],
+        columnRect = [[self tableView] rectOfColumn:aColumnIndex];
         
-    var tableRange = _tableView._tableColumnRanges[aColumnIndex],
-        bounds = [self bounds];
-
-    var rMinX = ROUND(tableRange.location);
-    bounds.origin.x = rMinX;
-    bounds.size.width = FLOOR(tableRange.length + tableRange.location - rMinX);
+    headerRect.origin.x = CPRectGetMinX(columnRect);
+    headerRect.size.width = CPRectGetWidth(columnRect);
     
-    return bounds;
+    return headerRect;
 }
 
 - (CGRect)_cursorRectForColumn:(int)column

AppKit/CPTableView.j

@@ -690,6 +690,24 @@ CPTableViewFirstColumnOnlyAutoresizingStyle = 5;
     [self setNeedsLayout];
 }
 
+/*!
+    @ignore
+*/
+- (void)_tableColumnVisibilityDidChange:(CPTableColumn)aColumn
+{
+    var columnIndex = [[self tableColumns] indexOfObjectIdenticalTo:aColumn];
+    
+    if (_dirtyTableColumnRangeIndex < 0)
+        _dirtyTableColumnRangeIndex = columnIndex;
+    else
+        _dirtyTableColumnRangeIndex = MIN(columnIndex, _dirtyTableColumnRangeIndex);
+    
+    [[self headerView] setNeedsLayout];
+    [[self headerView] setNeedsDisplay:YES];
+    
+    [self reloadData];
+}
+
 - (CPArray)tableColumns
 {
     return _tableColumns;
@@ -1044,6 +1062,8 @@ CPTableViewFirstColumnOnlyAutoresizingStyle = 5;
     if (_dirtyTableColumnRangeIndex < 0)
         return;
 
+    _numberOfHiddenColumns = 0;
+
     var index = _dirtyTableColumnRangeIndex,
         count = NUMBER_OF_COLUMNS(),
         x = index === 0 ? 0.0 : CPMaxRange(_tableColumnRanges[index - 1]);
@@ -1053,7 +1073,10 @@ CPTableViewFirstColumnOnlyAutoresizingStyle = 5;
         var tableColumn = _tableColumns[index];
 
         if ([tableColumn isHidden])
+        {
+            _numberOfHiddenColumns += 1;
             _tableColumnRanges[index] = CPMakeRange(x, 0.0);
+        }
 
         else
         {
@@ -1074,8 +1097,10 @@ CPTableViewFirstColumnOnlyAutoresizingStyle = 5;
 - (CGRect)rectOfColumn:(CPInteger)aColumnIndex
 {
     aColumnIndex = +aColumnIndex;
+    
+    var column = [[self tableColumns] objectAtIndex:aColumnIndex];
 
-    if (aColumnIndex < 0 || aColumnIndex >= NUMBER_OF_COLUMNS())
+    if ([column isHidden] || aColumnIndex < 0 || aColumnIndex >= NUMBER_OF_COLUMNS())
         return _CGRectMakeZero();
 
     UPDATE_COLUMN_RANGES_IF_NECESSARY();
@@ -2042,10 +2067,14 @@ CPTableViewFirstColumnOnlyAutoresizingStyle = 5;
         columnsCount = columnArray.length;
 
     for (; columnIndex < columnsCount; ++columnIndex)
-    {
+    {        
         var column = columnArray[columnIndex],
-            tableColumn = _tableColumns[column],
-            tableColumnUID = [tableColumn UID];
+            tableColumn = _tableColumns[column];
+            
+        if ([tableColumn isHidden])
+            continue;
+            
+        var tableColumnUID = [tableColumn UID];
 
         if (!_dataViewsForTableColumns[tableColumnUID])
             _dataViewsForTableColumns[tableColumnUID] = [];
@@ -2158,6 +2187,9 @@ CPTableViewFirstColumnOnlyAutoresizingStyle = 5;
 
 - (void)_enqueueReusableDataView:(CPView)aDataView
 {
+    if (!aDataView)
+        return;
+    
     // FIXME: yuck!
     var identifier = aDataView.identifier;