DatePicker

“DatePicker” is a Cocoa sample application that demonstrates how to use NSDatePicker control on Mac OS X. NSDatePicker is a subclass of NSControl that provides for visually displaying and editing an NSDate instance.

This control uses an NSDatePickerCell to implement much of the control’s functionality.

About the Sample

DatePicker shows how to manipulate the behaviors of lNSDatePicker in the following ways

  1. Changing the picker style.
  2. Changing the picker font size.
  3. Changing the background/text color as well as other appearance aspects.
  4. Turning on and off the various date and time element flags.
  5. Setting the minimum and maximum dates.
  6. Overriding the set date as a delegate.

The sample also shows how to use the various date and time formats using the NSDateFormatter class.

Sources

MyWindowController.py

import objc
import Cocoa

# date/time element popup selections:
kNSHourMinuteDatePickerElementFlag = 0
kNSHourMinuteSecondDatePickerElementFlag = 1
kNSTimeZoneDatePickerElementFlag = 2

kNSYearMonthDatePickerElementFlag = 0
kNSYearMonthDayDatePickerElementFlag = 1
kNSEraDatePickerElementFlag = 2

kSingleDateMode = 0
kRangeDateMode = 1



class MyWindowController (Cocoa.NSWindowController):
    datePickerControl = objc.ivar()
    shrinkGrowFactor = objc.ivar.int()

    outerBox                = objc.IBOutlet()
    datePickerPlaceHolder   = objc.IBOutlet()

    dateResult1             = objc.IBOutlet()
    dateResult2             = objc.IBOutlet()
    dateResult3             = objc.IBOutlet()
    dateResult4             = objc.IBOutlet()
    dateResult5             = objc.IBOutlet()

    # appearance
    pickerStylePopup        = objc.IBOutlet()
    drawsBackgroundCheck    = objc.IBOutlet()
    bezeledCheck            = objc.IBOutlet()
    borderedCheck           = objc.IBOutlet()
    backColorWell           = objc.IBOutlet()
    textColorWell           = objc.IBOutlet()
    fontSizePopup           = objc.IBOutlet()

    # date and time
    dateElementChecks       = objc.IBOutlet()
    timeElementChecks       = objc.IBOutlet()
    overrideDateCheck       = objc.IBOutlet()
    overrideDate            = objc.IBOutlet()

    # date range
    datePickerModeRadios    = objc.IBOutlet()
    secondsRangeEdit        = objc.IBOutlet()
    secondsRangeEditLabel   = objc.IBOutlet()

    minDatePicker           = objc.IBOutlet()
    maxDatePicker           = objc.IBOutlet()
    setMinDateButton        = objc.IBOutlet()
    setMaxDateButton        = objc.IBOutlet()
    clearMinDateButton      = objc.IBOutlet()
    clearMaxDateButton      = objc.IBOutlet()

    def awakeFromNib(self):
        # based our date formatter on CFDateFormatter: allows more configurability and better localization
        Cocoa.NSDateFormatter.setDefaultFormatterBehavior_(Cocoa.NSDateFormatterBehavior10_4)

        self.setupDatePickerControl_(Cocoa.NSClockAndCalendarDatePickerStyle)

        # setup the initial Cocoa.NSDatePickerElementFlags since we are using picker style:
        # Cocoa.NSClockAndCalendarDatePickerStyle
        flags = (
                  Cocoa.NSYearMonthDatePickerElementFlag
                | Cocoa.NSYearMonthDayDatePickerElementFlag
                | Cocoa.NSEraDatePickerElementFlag
                | Cocoa.NSHourMinuteDatePickerElementFlag
                | Cocoa.NSHourMinuteSecondDatePickerElementFlag
                | Cocoa.NSTimeZoneDatePickerElementFlag
            )
        self.datePickerControl.setDatePickerElements_(flags)

        self.datePickerModeRadios.cellWithTag_(1).setEnabled_(False)   # not currently implemened in 10.4.x and earlier

        self.minDatePicker.setDateValue_(Cocoa.NSDate.date())
        self.maxDatePicker.setDateValue_(Cocoa.NSDate.distantFuture())

        self.updateControls()        # force update of all UI elements and the picker itself

    def applicationShouldTerminateAfterLastWindowClosed_(self, sender):
        return True

    def setupDatePickerControl_(self, pickerStyle):
        # we need to re-create the picker control (due to a resize bug when switching between styles)
        if self.datePickerControl is not None:        # hide and release the previous date picker, if any
            self.datePickerControl.setHidden_(True)
            self.datePickerControl.setNeedsDisplay_(True)
            self.datePickerControl = None

        frame = self.datePickerPlaceHolder.frame()
        self.shrinkGrowFactor = frame.size.height - 30

        # create the date picker control if not created already
        if self.datePickerControl is None:
            self.datePickerControl = Cocoa.NSDatePicker.alloc().initWithFrame_(frame)

        self.datePickerControl.setFrameOrigin_(Cocoa.NSMakePoint(1,0))        # nudge the control placement a little

        self.datePickerControl.setDatePickerStyle_(pickerStyle)        # set our desired picker style

        self.datePickerPlaceHolder.addSubview_(self.datePickerControl)        # embed into our placeholder
        self.datePickerControl.setDrawsBackground_(True)
        self.datePickerControl.setBezeled_(True)
        self.datePickerControl.setBordered_(False)
        self.datePickerControl.setEnabled_(True)

        self.datePickerControl.setTextColor_(self.textColorWell.color())
        self.datePickerControl.setBackgroundColor_(self.backColorWell.color())

        # always set the date/time to TODAY
        # note that our delete override might block this...
        self.datePickerControl.setDateValue_(Cocoa.NSDate.date())

        self.datePickerControl.setNeedsDisplay_(True)
        self.updateControls()        # force update of all UI elements and the picker itself

        # synch the picker style popup with the new style change
        self.pickerStylePopup.selectItemWithTag_(pickerStyle)

        # we want to be the cell's delegate to catch date validation
        self.datePickerControl.setDelegate_(self)
        # or we can set us as the delegate to its cell like so:
        #                self.datePickerControl.cell().setDelegate_(self)

        # we want to respond to date/time changes
        self.datePickerControl.setAction_('datePickerAction:')


    def updateDateResult(self):
        theDate = self.datePickerControl.dateValue()
        if theDate is not None:
            formatter = Cocoa.NSDateFormatter.alloc().init()

            # some examples:
            # formatter.setDateStyle_(Cocoa.NSDateFormatterNoStyle)            # <no date displayed>
            # formatter.setDateStyle_(Cocoa.NSDateFormatterMediumStyle)        # Jan 24, 1984
            # formatter.setDateStyle_(Cocoa.NSDateFormatterShortStyle)         # 1/24/84
            # formatter.setDateStyle_(Cocoa.NSDateFormatterLongStyle)          # January 24, 1984
            # formatter.setDateStyle_(Cocoa.NSDateFormatterFullStyle)          # Tuesday, January 24, 1984
            #
            # formatter.setTimeStyle_(Cocoa.NSDateFormatterNoStyle)            # <no time displayed>
            # formatter.setTimeStyle_(Cocoa.NSDateFormatterShortStyle)         # 2:44 PM
            # formatter.setTimeStyle_(Cocoa.NSDateFormatterMediumStyle)        # 2:44:55 PM
            # formatter.setTimeStyle_(Cocoa.NSDateFormatterLongStyle)          # 2:44:55 PM PDT
            # formatter.setTimeStyle_(Cocoa.NSDateFormatterFullStyle)          # 2:44:55 PM PDT
            #

            formatter.setDateStyle_(Cocoa.NSDateFormatterShortStyle)
            formatter.setTimeStyle_(Cocoa.NSDateFormatterNoStyle)
            formattedDateString = formatter.stringFromDate_(theDate)
            self.dateResult1.setStringValue_(formattedDateString)

            formatter.setDateStyle_(Cocoa.NSDateFormatterShortStyle)
            formatter.setTimeStyle_(Cocoa.NSDateFormatterShortStyle)
            formattedDateString = formatter.stringFromDate_(theDate)
            self.dateResult2.setStringValue_(formattedDateString)

            formatter.setDateStyle_(Cocoa.NSDateFormatterMediumStyle)
            formatter.setTimeStyle_(Cocoa.NSDateFormatterShortStyle)
            formattedDateString = formatter.stringFromDate_(theDate)
            self.dateResult3.setStringValue_(formattedDateString)

            formatter.setDateStyle_(Cocoa.NSDateFormatterLongStyle)
            formatter.setTimeStyle_(Cocoa.NSDateFormatterShortStyle)
            formattedDateString = formatter.stringFromDate_(theDate)
            self.dateResult4.setStringValue_(formattedDateString)

            formatter.setDateStyle_(Cocoa.NSDateFormatterFullStyle)
            formatter.setTimeStyle_(Cocoa.NSDateFormatterFullStyle)
            formattedDateString = formatter.stringFromDate_(theDate)
            self.dateResult5.setStringValue_(formattedDateString)

    def updateControls(self):
        self.datePickerControl.setNeedsDisplay_(True) # force it to update

        self.updateDatePickerMode()
        self.updateDateTimeElementFlags()
        self.updateDateResult()

    @objc.IBAction
    def setPickerStyle_(self, sender):
        tag = sender.selectedCell().tag()

        windowFrame = self.window().frame()
        boxFrame = self.outerBox.frame()

        self.datePickerControl.setHidden_(True)

        if tag == Cocoa.NSClockAndCalendarDatePickerStyle:
            # for this picker style, we need to grow the window to make room

            windowFrame.size.height += self.shrinkGrowFactor;
            windowFrame.origin.y -= self.shrinkGrowFactor;

            boxFrame.size.height += self.shrinkGrowFactor;
            self.outerBox.setFrame_(boxFrame)

            self.window().setFrame_display_animate_(windowFrame, True, True)

            # set our desired picker style
            self.datePickerControl.setDatePickerStyle_(Cocoa.NSClockAndCalendarDatePickerStyle)

            # shows these last
            self.dateResult1.setHidden_(False)
            self.dateResult2.setHidden_(False)
            self.dateResult3.setHidden_(False)
            self.dateResult4.setHidden_(False)

        else:
            currentPickerStyle = self.datePickerControl.datePickerStyle()

            # shrink the window only if the current style is "clock and calendar"
            if currentPickerStyle == Cocoa.NSClockAndCalendarDatePickerStyle:
                # hide these first
                self.dateResult1.setHidden_(True)
                self.dateResult2.setHidden_(True)
                self.dateResult3.setHidden_(True)
                self.dateResult4.setHidden_(True)

                windowFrame.size.height -= self.shrinkGrowFactor
                windowFrame.origin.y += self.shrinkGrowFactor

                boxFrame.size.height -= self.shrinkGrowFactor
                self.outerBox.setFrame_(boxFrame)

                self.window().setFrame_display_animate_(windowFrame, True, True)

            self.setupDatePickerControl_(tag) # set our desired picker style

        self.datePickerControl.setHidden_(False)

        self.updateControls()        # force update of all UI elements and the picker itself

    @objc.IBAction
    def setFontSize_(self, sender):
        tag = sender.selectedCell().tag()
        if tag == Cocoa.NSMiniControlSize:
            self.datePickerControl.cell().setControlSize_(Cocoa.NSMiniControlSize)
            self.datePickerControl.cell().setFont_(Cocoa.NSFont.systemFontOfSize_(9.0))

        elif tag == Cocoa.NSSmallControlSize:
            self.datePickerControl.cell().setControlSize_(Cocoa.NSSmallControlSize)
            self.datePickerControl.cell().setFont_(Cocoa.NSFont.systemFontOfSize_(11.0))

        elif tag == Cocoa.NSRegularControlSize:
            self.datePickerControl.cell().setControlSize_(Cocoa.NSRegularControlSize)
            self.datePickerControl.cell().setFont_(Cocoa.NSFont.systemFontOfSize_(13.0))

    @objc.IBAction
    def datePickerAction_(self, sender):
        self.updateDateResult()

    @objc.IBAction
    def dateOverrideAction_(self, sender):
        checked = sender.selectedCell().state()
        if checked:
            self.datePickerControl.setDelegate_(self)

        else:
            self.datePickerControl.setDelegate_(None)

        self.datePickerControl.setDateValue_(Cocoa.NSDate.date()) # force the delete "datePickerCell" to be called

    def datePickerCell_validateProposedDateValue_timeInterval_(self, aDatePickerCell, proposedDateValue, proposedTimeInterval):
        controller = aDatePickerCell.delegate()

        if controller is self and aDatePickerCell is self.datePickerControl.cell():
            # override the date and time?
            if self.overrideDateCheck.cell().state():
                # override the date using the user specified date
                return (self.overrideDate.dateValue(), proposedTimeInterval)

        return (proposedDateValue, proposedTimeInterval)

    @objc.IBAction
    def setDrawsBackground_(self, sender):
        self.datePickerControl.setDrawsBackground_(sender.state())

    @objc.IBAction
    def setBackgroundColor_(self, sender):
        newColor = sender.color()
        self.datePickerControl.setBackgroundColor_(newColor)

    @objc.IBAction
    def setTextColor_(self, sender):
        newColor = sender.color()
        self.datePickerControl.setTextColor_(newColor)

    @objc.IBAction
    def setBezeled_(self, sender):
        self.datePickerControl.setBezeled_(sender.state())

    @objc.IBAction
    def setBordered_(self, sender):
        self.datePickerControl.setBordered_(sender.state())


    @objc.IBAction
    def setDateElementFlags_(self, sender):
        tag = sender.selectedCell().tag()
        flags = self.datePickerControl.datePickerElements()

        checked = sender.selectedCell().state()

        if tag == kNSYearMonthDatePickerElementFlag:
            if checked:
                flags |= Cocoa.NSYearMonthDatePickerElementFlag
            else:
                flags ^= Cocoa.NSYearMonthDatePickerElementFlag

        elif tag == kNSYearMonthDayDatePickerElementFlag:
            if checked:
                flags |= Cocoa.NSYearMonthDayDatePickerElementFlag
            else:
                flags ^= Cocoa.NSYearMonthDayDatePickerElementFlag

        elif tag == kNSEraDatePickerElementFlag:
            if checked:
                flags |= Cocoa.NSEraDatePickerElementFlag
            else:
                flags ^= Cocoa.NSEraDatePickerElementFlag

        self.datePickerControl.setDatePickerElements_(flags)

        self.updateControls() # force update of all UI elements and the picker itself

    @objc.IBAction
    def setTimeElementFlags_(self, sender):
        tag = sender.selectedCell().tag()
        flags = self.datePickerControl.datePickerElements()

        checked = sender.selectedCell().state()

        if tag == kNSHourMinuteDatePickerElementFlag:
            if checked:
                flags |= Cocoa.NSHourMinuteDatePickerElementFlag
            else:
                flags ^= Cocoa.NSHourMinuteDatePickerElementFlag

        elif tag == kNSHourMinuteSecondDatePickerElementFlag:
            if checked:
                flags |= Cocoa.NSHourMinuteSecondDatePickerElementFlag
            else:
                flags ^= Cocoa.NSHourMinuteSecondDatePickerElementFlag

        elif tag == kNSTimeZoneDatePickerElementFlag:
            if checked:
                flags |= Cocoa.NSTimeZoneDatePickerElementFlag
            else:
                flags ^= Cocoa.NSTimeZoneDatePickerElementFlag

        self.datePickerControl.setDatePickerElements_(flags)

        self.updateControls() # force update of all UI elements and the picker itself

    def updateDateTimeElementFlags(self):
        elementFlags = self.datePickerControl.datePickerElements()

        # time elements
        if (elementFlags & Cocoa.NSHourMinuteDatePickerElementFlag) != 0:
            self.timeElementChecks.selectCellWithTag_(0)
        if (elementFlags & Cocoa.NSHourMinuteSecondDatePickerElementFlag) != 0:
            self.timeElementChecks.selectCellWithTag_(1)
        if (elementFlags & Cocoa.NSTimeZoneDatePickerElementFlag) != 0:
            self.timeElementChecks.selectCellWithTag_(2)

        # date elements
        if (elementFlags & Cocoa.NSYearMonthDatePickerElementFlag) != 0:
            self.dateElementChecks.selectCellWithTag_(0)
        if (elementFlags & Cocoa.NSYearMonthDayDatePickerElementFlag) != 0:
            self.dateElementChecks.selectCellWithTag_(1)
        if (elementFlags & Cocoa.NSEraDatePickerElementFlag) != 0:
            self.dateElementChecks.selectCellWithTag_(2)


    @objc.IBAction
    def setMinDate_(self, sender):
        self.datePickerControl.setMinDate_(self.minDatePicker.dateValue())
        self.setMinDateButton.setEnabled_(False)
        self.clearMinDateButton.setEnabled_(True)


    @objc.IBAction
    def setMaxDate_(self, sender):
        self.datePickerControl.setMaxDate_(self.maxDatePicker.dateValue())
        self.setMaxDateButton.setEnabled_(False)
        self.clearMaxDateButton.setEnabled_(True)

    @objc.IBAction
    def clearMinDate_(self, sender):
        self.datePickerControl.setMinDate_(NSDate.distantPast())
        self.clearMinDateButton.setEnabled_(False)
        self.setMinDateButton.setEnabled_(True)


    @objc.IBAction
    def clearMaxDate_(self, sender):
        self.datePickerControl.setMaxDate_(NSDate.distantFuture())
        self.clearMaxDateButton.setEnabled_(False)
        self.setMaxDateButton.setEnabled_(True)

    @objc.IBAction
    def setDatePickerMode_(self, sender):
        tag = sender.selectedCell().tag()

        if tag == kSingleDateMode:
            self.datePickerControl.setDatePickerMode_(NSSingleDateMode)

        elif tag == kRangeDateMode:
            self.datePickerControl.setDatePickerMode_(NSRangeDateMode)

        self.updateControls() # force update of all UI elements and the picker itself


    def updateDatePickerMode(self):
        mode = self.datePickerControl.datePickerMode()
        if mode == Cocoa.NSSingleDateMode:
            self.datePickerModeRadios.selectCellWithTag_(0)

            # interval value not applicable:
            self.secondsRangeEdit.setEnabled_(False)
            self.secondsRangeEditLabel.setTextColor_(Cocoa.NSColor.lightGrayColor())

            self.datePickerControl.setTimeInterval_(0)

        elif mode == Cocoa.NSRangeDateMode:
            self.datePickerModeRadios.selectCellWithTag_(1)

            # interval value applies:
            self.secondsRangeEdit.setEnabled_(True)
            self.secondsRangeEditLabel.setTextColor_(Cocoa.NSColor.blackColor())

            # set the date range by start date (here we use the current date in the date picker
            # control), and time interval (in seconds)
            secsStr = self.secondsRangeEdit.stringValue()
            numSeconds = int(secsStr)
            self.datePickerControl.setTimeInterval_(numSeconds)

    def controlTextDidEndEditing_(self, notification):
        self.updateDatePickerMode()        # force update of the date picker control

main.py

from PyObjCTools import AppHelper

import MyWindowController

AppHelper.runEventLoop()

setup.py

"""
Script for building the example.

Usage:
    python3 setup.py py2app
"""
from setuptools import setup

setup(
    name="DatePicker",
    app=["main.py"],
    data_files=["English.lproj"],
    setup_requires=[
        "py2app",
        "pyobjc-framework-Cocoa",
    ]
)

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