Fixed: CPDatePicker freeze when hidden

Previously the CPDatePicker freezed when trying to hide it when it was the firstResponder.
There was an intern problem in the CPDatePickerTextField about the nextKeyView. That's why there was a boundless loop and the freeze.
This PR also fixed a big about the previous and next textField in the CPDatePicker.
It also fixed a bug about the CPDatePicker when it becomes firstResponder.

Fixes #1909

AppKit/CPDatePicker/_CPDatePickerTextField.j

@@ -177,6 +177,8 @@ var CPZeroKeyCode = 48,
 
 - (void)_selecteTextFieldWithFlags:(unsigned)flags
 {
+    [_datePickerElementView _updateResponderTextField];
+
     // We select the firstTextField when the datePicker becomes firstResponder if _currentTextField is null. It can be null just when using tab
     if (!_currentTextField)
     {
@@ -300,7 +302,7 @@ var CPZeroKeyCode = 48,
             return YES;
         }
 
-        [self _selectTextField:[_currentTextField previousKeyView]];
+        [self _selectTextField:[_currentTextField previousTextField]];
         return YES;
     }
 
@@ -313,11 +315,8 @@ var CPZeroKeyCode = 48,
                 [[self window] makeFirstResponder:[_datePicker nextKeyView]];
 
             return YES;
-        }
 
-        [self _selectTextField:[_currentTextField nextKeyView]];
-        return YES;
-    }
+        } [self _selectTextField:[_currentTextField nextTextField]]; return YES; }
 
     if ([anEvent keyCode] == CPReturnKeyCode && _timerEdition)
     {
@@ -1076,6 +1075,12 @@ var CPZeroKeyCode = 48,
 /*! Update the nextTextField params of all of the textField. This is used to move the current textField with the arrows
 */
 - (void)_updateKeyView
+{
+    [self _updateNextTextField];
+    [self _updatePreviousTextField]
+}
+
+- (void)_updateNextTextField
 {
     var datePickerElements = [_datePicker datePickerElements],
         firstTexField = _textFieldMonth,
@@ -1089,45 +1094,94 @@ var CPZeroKeyCode = 48,
     }
 
     if ((datePickerElements & CPYearMonthDayDatePickerElementFlag) == CPYearMonthDayDatePickerElementFlag)
-        [firstTexField setNextKeyView:secondTextField];
+        [firstTexField setNextTextField:secondTextField];
     else
-        [firstTexField setNextKeyView:_textFieldYear];
+        [firstTexField setNextTextField:_textFieldYear];
 
-    [secondTextField setNextKeyView:_textFieldYear];
+    [secondTextField setNextTextField:_textFieldYear];
 
     if (datePickerElements & CPHourMinuteSecondDatePickerElementFlag || datePickerElements & CPHourMinuteDatePickerElementFlag)
-        [_textFieldYear setNextKeyView:_textFieldHour];
+        [_textFieldYear setNextTextField:_textFieldHour];
     else if (isEnglishFormat || (datePickerElements & CPYearMonthDayDatePickerElementFlag) == CPYearMonthDayDatePickerElementFlag)
-        [_textFieldYear setNextKeyView:firstTexField];
+        [_textFieldYear setNextTextField:firstTexField];
     else
-        [_textFieldYear setNextKeyView:secondTextField];
+        [_textFieldYear setNextTextField:secondTextField];
 
-    [_textFieldHour setNextKeyView:_textFieldMinute];
+    [_textFieldHour setNextTextField:_textFieldMinute];
 
     if ((datePickerElements & CPHourMinuteSecondDatePickerElementFlag) == CPHourMinuteSecondDatePickerElementFlag)
-        [_textFieldMinute setNextKeyView:_textFieldSecond];
+        [_textFieldMinute setNextTextField:_textFieldSecond];
     else if (isEnglishFormat)
-        [_textFieldMinute setNextKeyView:_textFieldPMAM];
+        [_textFieldMinute setNextTextField:_textFieldPMAM];
     else if ((datePickerElements & CPYearMonthDayDatePickerElementFlag) == CPYearMonthDayDatePickerElementFlag)
-        [_textFieldMinute setNextKeyView:firstTexField];
+        [_textFieldMinute setNextTextField:firstTexField];
     else if (datePickerElements & CPYearMonthDatePickerElementFlag)
-        [_textFieldMinute setNextKeyView:secondTextField];
+        [_textFieldMinute setNextTextField:secondTextField];
     else
-        [_textFieldMinute setNextKeyView:_textFieldHour];
+        [_textFieldMinute setNextTextField:_textFieldHour];
 
     if (isEnglishFormat)
-        [_textFieldSecond setNextKeyView:_textFieldPMAM];
+        [_textFieldSecond setNextTextField:_textFieldPMAM];
     else if ((datePickerElements & CPYearMonthDayDatePickerElementFlag) == CPYearMonthDayDatePickerElementFlag)
-        [_textFieldSecond setNextKeyView:firstTexField];
+        [_textFieldSecond setNextTextField:firstTexField];
     else if (datePickerElements & CPYearMonthDatePickerElementFlag)
-        [_textFieldSecond setNextKeyView:secondTextField];
+        [_textFieldSecond setNextTextField:secondTextField];
     else
-        [_textFieldSecond setNextKeyView:_textFieldHour];
+        [_textFieldSecond setNextTextField:_textFieldHour];
 
     if (datePickerElements & CPYearMonthDayDatePickerElementFlag)
-        [_textFieldPMAM setNextKeyView:_textFieldMonth];
+        [_textFieldPMAM setNextTextField:_textFieldMonth];
     else
-        [_textFieldPMAM setNextKeyView:_textFieldHour];
+        [_textFieldPMAM setNextTextField:_textFieldHour];
+}
+
+- (void)_updatePreviousTextField
+{
+    var datePickerElements = [_datePicker datePickerElements],
+        firstTexField = _textFieldMonth,
+        secondTextField = _textFieldDay,
+        isEnglishFormat = [_datePicker _isEnglishFormat];
+
+    if (!isEnglishFormat)
+    {
+        firstTexField = _textFieldDay;
+        secondTextField = _textFieldMonth;
+    }
+
+    if ((datePickerElements & CPHourMinuteSecondDatePickerElementFlag) == CPHourMinuteSecondDatePickerElementFlag)
+        [_textFieldPMAM setPreviousTextField:_textFieldSecond];
+    else if (datePickerElements & CPHourMinuteDatePickerElementFlag)
+        [_textFieldPMAM setPreviousTextField:_textFieldMinute];
+
+    [_textFieldSecond setPreviousTextField:_textFieldMinute];
+    [_textFieldMinute setPreviousTextField:_textFieldHour];
+
+    if (datePickerElements & CPYearMonthDatePickerElementFlag)
+        [_textFieldHour setPreviousTextField:_textFieldYear];
+    else if (isEnglishFormat)
+        [_textFieldHour setPreviousTextField:_textFieldPMAM];
+    else if ((datePickerElements & CPHourMinuteSecondDatePickerElementFlag) == CPHourMinuteSecondDatePickerElementFlag)
+        [_textFieldHour setPreviousTextField:_textFieldSecond];
+    else
+        [_textFieldHour setPreviousTextField:_textFieldMinute];
+
+    if (!isEnglishFormat)
+        [_textFieldYear setPreviousTextField:_textFieldMonth];
+    else if ((datePickerElements & CPYearMonthDayDatePickerElementFlag) == CPYearMonthDayDatePickerElementFlag)
+        [_textFieldYear setPreviousTextField:_textFieldDay];
+    else
+        [_textFieldYear setPreviousTextField:_textFieldMonth];
+
+    [secondTextField setPreviousTextField:firstTexField];
+
+    if (isEnglishFormat && datePickerElements & CPHourMinuteDatePickerElementFlag)
+        [firstTexField setPreviousTextField:_textFieldPMAM];
+    else if ((datePickerElements & CPHourMinuteSecondDatePickerElementFlag) == CPHourMinuteSecondDatePickerElementFlag)
+        [firstTexField setPreviousTextField:_textFieldSecond];
+    else if (datePickerElements & CPHourMinuteDatePickerElementFlag)
+        [firstTexField setPreviousTextField:_textFieldMinute];
+    else
+        [firstTexField setPreviousTextField:_textFieldYear];
 }
 
 @end
@@ -1145,6 +1199,9 @@ var CPMonthDateType = 0,
 */
 @implementation _CPDatePickerElementTextField : CPTextField
 {
+    _CPDatePickerElementTextField _nextTextField        @accessors(property=nextTextField);
+    _CPDatePickerElementTextField _previousTextField    @accessors(property=previousTextField);
+
     CPDatePicker    _datePicker @accessors(setter=setDatePicker:);
 
     int _dateType  @accessors(getter=dateType);