From a70bc7d9532b52a0c8ac596332e60f40e1c244b2 Mon Sep 17 00:00:00 2001
From: Alexander Ljungberg <aljungberg@slevenbits.com>
Date: Sun, 14 Oct 2012 18:27:25 +0100
Subject: [PATCH] "Creates Sort Descriptors" `CPTableColumn` value binding
 option.

With this option an array controller driven table view can be sorted by clicking the table column headers without manually setting up sort descriptor prototypes.

If `CPCreatesSortDescriptorBindingOption` is enabled on a table column value binding, sort descriptors will be created automatically. The default value for this option is YES.
---
 AppKit/CPTableColumn.j | 32 +++++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/AppKit/CPTableColumn.j b/AppKit/CPTableColumn.j
index b0349993d..6a1765cad 100644
--- a/AppKit/CPTableColumn.j
+++ b/AppKit/CPTableColumn.j
@@ -494,7 +494,13 @@ CPTableColumnUserResizingMask   = 1 << 1;
 */
 - (CPSortDescriptor)sortDescriptorPrototype
 {
-    return _sortDescriptorPrototype;
+    if (_sortDescriptorPrototype)
+        return _sortDescriptorPrototype;
+
+    var binderClass = [[self class] _binderClassForBinding:CPValueBinding],
+        binding = [binderClass getBinding:CPValueBinding forObject:self];
+
+    return [binding _defaultSortDescriptorPrototype];
 }
 
 /*!
@@ -570,6 +576,30 @@ CPTableColumnUserResizingMask   = 1 << 1;
     [tableView reloadDataForRowIndexes:rowIndexes columnIndexes:columnIndexes];
 }
 
+- (CPSortDescriptor)_defaultSortDescriptorPrototype
+{
+    if (![self createsSortDescriptor])
+        return nil;
+
+    var keyPath = [_info objectForKey:CPObservedKeyPathKey],
+        dotIndex = keyPath.lastIndexOf(".");
+
+    if (dotIndex === CPNotFound)
+        return nil;
+
+    var firstPart = keyPath.substring(0, dotIndex),
+        key = keyPath.substring(dotIndex + 1);
+
+    return [CPSortDescriptor sortDescriptorWithKey:key ascending:YES];
+}
+
+- (BOOL)createsSortDescriptor
+{
+    var options = [_info objectForKey:CPOptionsKey],
+        optionValue = [options objectForKey:CPCreatesSortDescriptorBindingOption];
+    return optionValue === nil ? YES : [optionValue boolValue];
+}
+
 @end
 
 @implementation CPTableColumn (Bindings)