Update implementation to calculate position of items for the flow layout. implementation of copyWithZone. Implementation of initWithCoder for flow layout

Headers/AppKit/NSCollectionViewLayout.h

@@ -95,6 +95,9 @@ NSCollectionViewSupplementaryElementKind NSCollectionElementKindInterItemGapIndi
 - (NSCollectionElementCategory) representedElementCategory;
 - (NSString *) representedElementKind;
 
+- (NSInteger) zIndex;
+- (void) setZIndex: (NSInteger)zIndex;
+  
 @end
 
 enum

Source/NSCollectionView.m

@@ -1373,18 +1373,28 @@ static NSString *placeholderItem = nil;
   if (loaded)
     {
       NSView *v = [item view];
-      NSCollectionViewLayoutAttributes *attrs =
-        [_collectionViewLayout layoutAttributesForItemAtIndexPath: path];
-      NSRect frame = [attrs frame];
-      BOOL hidden = [attrs isHidden];
-      CGFloat alpha = [attrs alpha];
-      NSSize sz = [attrs size];
-      
-      // set attributes of item based on currently selected layout...
-      frame.size = sz;
-      [v setFrame: frame];
-      [v setHidden: hidden];
-      [v setAlphaValue: alpha];
+      if (_collectionViewLayout)
+        {
+          NSCollectionViewLayoutAttributes *attrs =
+            [_collectionViewLayout layoutAttributesForItemAtIndexPath: path];
+          NSRect frame = [attrs frame];
+          BOOL hidden = [attrs isHidden];
+          CGFloat alpha = [attrs alpha];
+          NSSize sz = [attrs size];
+          
+          // set attributes of item based on currently selected layout...
+          frame.size = sz;
+          [v setFrame: frame];
+          [v setHidden: hidden];
+          [v setAlphaValue: alpha];
+          
+          // NSLog(@"v = %@, a = %@, l = %@", v, attrs, _collectionViewLayout);
+          [self addSubview: v];
+        }
+      else
+        {
+          NSLog(@"Layout view is not set");
+        }
     }
   else
     {

Source/NSCollectionViewFlowLayout.m

@@ -22,7 +22,10 @@
    Boston, MA 02110 USA.
 */
 
+#import <Foundation/NSIndexPath.h>
+
 #import "AppKit/NSCollectionViewFlowLayout.h"
+#import "AppKit/NSCollectionViewItem.h"
 
 @implementation NSCollectionViewFlowLayoutInvalidationContext
 
@@ -61,6 +64,27 @@
 
 @implementation NSCollectionViewFlowLayout
 
+- (id) initWithCoder: (NSCoder *)coder
+{
+  self = [super initWithCoder: coder];
+  if (self)
+    {
+      if ([coder allowsKeyedCoding])
+        {
+          _itemSize = [coder decodeSizeForKey: @"NSItemSize"];
+        }
+      else
+        {
+          _itemSize = [coder decodeSize];
+        }
+    }
+  return self;
+}
+
+- (void) encodeWithCoder: (NSCoder *)coder
+{
+}
+
 - (CGFloat) minimumLineSpacing
 {
   return _minimumLineSpacing;
@@ -187,8 +211,28 @@
 
 - (NSCollectionViewLayoutAttributes *) layoutAttributesForItemAtIndexPath: (NSIndexPath *)indexPath
 {
-  NSLog(@"Flow layout for index path = %@", indexPath);
-  return nil;
+  NSCollectionViewLayoutAttributes *attrs = [[NSCollectionViewLayoutAttributes alloc] init];
+  NSSize sz = [self itemSize];
+  NSInteger s = [indexPath section];
+  NSInteger r = [indexPath item];
+  CGFloat h = sz.height;
+  CGFloat w = sz.width;
+  NSRect f = NSMakeRect(r * w, s * h, h, w);
+  
+  // NSLog(@"Flow layout for index path = %@", indexPath);
+
+  [attrs setFrame: f];
+  [attrs setHidden: NO];
+  [attrs setZIndex: 0];
+  [attrs setSize: sz];
+
+  // NSLog(@"f = %@", NSStringFromRect(f));
+  // NSLog(@"s = %@", NSStringFromSize(sz));
+  // NSLog(@"self = %@", self);
+  
+  AUTORELEASE(attrs);
+  
+  return attrs;
 }
 
 - (NSCollectionViewLayoutAttributes *)

Source/NSCollectionViewLayout.m

@@ -100,6 +100,16 @@
   _indexPath = indexPath;
 }
 
+- (NSInteger) zIndex
+{
+  return _zIndex;
+}
+
+- (void) setZIndex: (NSInteger)zIndex
+{
+  _zIndex = zIndex;
+}
+
 - (NSCollectionElementCategory) representedElementCategory
 {
   return _representedElementCategory;
@@ -112,9 +122,25 @@
 
 - (id) copyWithZone: (NSZone *)z
 {
+  NSCollectionViewLayoutAttributes *a = [[NSCollectionViewLayoutAttributes allocWithZone: z] init];
+
+  [a setFrame: [self frame]];
+  [a setSize: [self size]];
+  [a setAlpha: [self alpha]];
+  [a setHidden: [self isHidden]];
+  [a setIndexPath: [self indexPath]];
+  [a setZIndex: [self zIndex]];
+  
   return self;
 }
 
+/*
+- (NSString *) description
+{
+  return [NSString stringWithFormat: @"%@ - f = %@, s = %@", [super description], NSStringFromRect(_frame), NSStringFromSize(_size)];
+}
+*/
+
 @end
 
 @implementation NSCollectionViewUpdateItem