Fixed: added optimization for releasing observers

AppKit/CPClipView.j

@@ -97,6 +97,9 @@
 
 - (void)_addObservers
 {
+    if (_isObserving)
+        return;
+
     [super _addObservers];
 
     if (_documentView)
@@ -105,6 +108,9 @@
 
 - (void)_removeObservers
 {
+    if (!_isObserving)
+        return;
+
     [super _removeObservers];
 
     if (_documentView)

AppKit/CPDatePicker/_CPDatePickerTextField.j

@@ -414,6 +414,9 @@ var CPZeroKeyCode = 48,
 
 - (void)_removeObservers
 {
+    if (!_isObserving)
+        return;
+
     [super _removeObservers];
 
     [[CPNotificationCenter defaultCenter] removeObserver:self name:CPDatePickerElementTextFieldBecomeFirstResponder object:self];
@@ -421,6 +424,9 @@ var CPZeroKeyCode = 48,
 
 - (void)_addObservers
 {
+    if (_isObserving)
+        return;
+
     [super _addObservers];
 
     [[CPNotificationCenter defaultCenter] addObserver:self selector:@selector(_datePickerElementTextFieldBecomeFirstResponder:) name:CPDatePickerElementTextFieldBecomeFirstResponder object:self];
@@ -554,6 +560,9 @@ var CPZeroKeyCode = 48,
 
 - (void)_removeObservers
 {
+    if (!_isObserving)
+        return;
+
     [super _removeObservers];
 
     [[CPNotificationCenter defaultCenter] removeObserver:self name:CPDatePickerElementTextFieldAMPMChangedNotification object:_textFieldPMAM];
@@ -561,6 +570,9 @@ var CPZeroKeyCode = 48,
 
 - (void)_addObservers
 {
+    if (_isObserving)
+        return;
+
     [super _addObservers];
 
     [[CPNotificationCenter defaultCenter] addObserver:self selector:@selector(_datePickerElementTextFieldAMPMChangedNotification:) name:CPDatePickerElementTextFieldAMPMChangedNotification object:_textFieldPMAM];

AppKit/CPRuleEditor/_CPRuleEditorViewSliceRow.j

@@ -65,9 +65,6 @@ var CONTROL_HEIGHT = 16.,
     [self addSubview:_subtractButton];
 
     [self setAutoresizingMask:CPViewWidthSizable];
-
-    var center = [CPNotificationCenter defaultCenter];
-    [center addObserver:self selector:@selector(_textDidChange:) name:CPControlTextDidChangeNotification object:nil];
 }
 
 - (CPButton)_createRowButton
@@ -481,6 +478,26 @@ var CONTROL_HEIGHT = 16.,
     [self layoutSubviews];
 }
 
+- (void)_addObservers
+{
+    if (_isObserving)
+        return;
+
+    [super _addObservers];
+
+    [[CPNotificationCenter defaultCenter] addObserver:self selector:@selector(_textDidChange:) name:CPControlTextDidChangeNotification object:nil];
+}
+
+- (void)_removeObservers
+{
+    if (!_isObserving)
+        return;
+
+    [super _removeObservers];
+
+    [[CPNotificationCenter defaultCenter] removeObserver:self name:CPControlTextDidChangeNotification object:nil];
+}
+
 - (void)drawRect:(CGRect)rect
 {
     [super drawRect:rect];

AppKit/CPSearchField.j

@@ -125,6 +125,9 @@ var RECENT_SEARCH_PREFIX = @"   ";
 
 - (void)_removeObservers
 {
+    if (!_isObserving)
+        return;
+
     [super _removeObservers];
 
     [[CPNotificationCenter defaultCenter] removeObserver:self name:CPControlTextDidChangeNotification object:self];
@@ -132,6 +135,9 @@ var RECENT_SEARCH_PREFIX = @"   ";
 
 - (void)_addObservers
 {
+    if (_isObserving)
+        return;
+
     [super _addObservers];
 
     [[CPNotificationCenter defaultCenter] addObserver:self selector:@selector(_searchFieldTextDidChange:) name:CPControlTextDidChangeNotification object:self];

AppKit/CPTableView.j

@@ -5127,12 +5127,18 @@ Your delegate can implement this method to avoid subclassing the tableview to ad
 
 - (void)_removeObservers
 {
+    if (!_isObserving)
+        return;
+
     [super _removeObservers];
     [self _stopObservingFirstResponder];
 }
 
 - (void)_addObservers
 {
+    if (_isObserving)
+        return;
+
     [super _addObservers];
     [self _startObservingFirstResponder];
 }

AppKit/CPTextField.j

@@ -822,12 +822,18 @@ CPTextFieldStatePlaceholder = CPThemeState("placeholder");
 
 - (void)_removeObservers
 {
+    if (!_isObserving)
+        return;
+
     [super _removeObservers];
     [self _setObserveWindowKeyNotifications:NO];
 }
 
 - (void)_addObservers
 {
+    if (_isObserving)
+        return;
+
     [super _addObservers];
 
     if ([self window] === self)

AppKit/CPView.j

@@ -842,6 +842,9 @@ var CPViewFlags                     = { },
 
 - (void)_removeObservers
 {
+    if (!_isObserving)
+        return;
+
     var count = [_subviews count];
 
     while (count--)