Display a selected date range (+ as the header) in DatePicker on Android

Question

Does anyone know if it's possible in an Android DatePicker, to:

a) Let a user ONLY select a given block of dates. e.g.. user taps on a "W" day, then we automatically highlight that weeks Sunday -> Friday date range (each day is selected)

b) In the header of the DatePicker, show the selected date range. eg. Sun, Jan 14 - Fri, Jan 19

Really appreciate anyone's help/advice on this.

Answer 1

For future readers!

Actually with new android material design components what you want achieve could be achieved using MaterialDatePicker. It's a dialog, not a custom view like android.widget.DatePicker.

---

Steps

1. Add material dependency to your module's gradle file

implementation 'com.google.android.material:material:1.1.0-beta01'

2. Change app theme to inherit from a version of material theme.

ex:

<style name="AppTheme" parent="Theme.MaterialComponents.Light.NoActionBar">

3. Use following code to initiate the dialog.

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        setupRangePickerDialog()

    }

    private fun setupRangePickerDialog() {
        val builderRange = MaterialDatePicker.Builder.dateRangePicker()

        builderRange.setCalendarConstraints(limitRange().build())
        val pickerRange = builderRange.build()
        pickerRange.show(supportFragmentManager, pickerRange.toString())
    }


    /*
    Limit selectable range to Oct 17 - Nov 20 2019
     */
    private fun limitRange(): CalendarConstraints.Builder {

        val constraintsBuilderRange = CalendarConstraints.Builder()

        val calendarStart: Calendar = Calendar.getInstance()
        val calendarEnd: Calendar = Calendar.getInstance()

        val year = 2019
        val startMonth = 10
        val startDate = 17

        val endMonth = 11
        val endDate = 20

        calendarStart.set(year, startMonth - 1, startDate - 1)
        calendarEnd.set(year, endMonth - 1, endDate)

        val minDate = calendarStart.timeInMillis
        val maxDate = calendarEnd.timeInMillis

        constraintsBuilderRange.setStart(minDate)
        constraintsBuilderRange.setEnd(maxDate)

        constraintsBuilderRange.setValidator(RangeValidator(minDate, maxDate))

        return constraintsBuilderRange
    }


}

class RangeValidator(private val minDate:Long, private val maxDate:Long) : CalendarConstraints.DateValidator{


    constructor(parcel: Parcel) : this(
        parcel.readLong(),
        parcel.readLong()
    )

    override fun writeToParcel(dest: Parcel?, flags: Int) {
        TODO("not implemented")
    }

    override fun describeContents(): Int {
        TODO("not implemented")
    }

    override fun isValid(date: Long): Boolean {
        return !(minDate > date || maxDate < date)

    }

    companion object CREATOR : Parcelable.Creator<RangeValidator> {
        override fun createFromParcel(parcel: Parcel): RangeValidator {
            return RangeValidator(parcel)
        }

        override fun newArray(size: Int): Array<RangeValidator?> {
            return arrayOfNulls(size)
        }
    }

}