TimePickerDialog with fixed android:timePickerMode spinner in Nougat

DatePickerDialogFixedNougatSpinner.java

package my.packagename;

import android.app.DatePickerDialog;
import android.content.Context;
import android.content.res.TypedArray;
import android.os.Build;
import android.util.AttributeSet;
import android.widget.DatePicker;

import java.lang.reflect.Field;
import java.lang.reflect.Method;

/**
 * I got it from https://gist.github.com/jeffdgr8/6bc5f990bf0c13a7334ce385d482af9f and
 * did some adjustments in order to work with `DatePicker`
 * Workaround for this bug: https://code.google.com/p/android/issues/detail?id=222208
 * In Android 7.0 Nougat, spinner mode for the DatePicker in DatePickerDialog is
 * incorrectly displayed as calendar, even when the theme specifies otherwise, such as:
 * <p>
 * <resources>
 * <style name="Theme.MyApp" parent="Theme.AppCompat.Light.NoActionBar">
 * <item name="android:datePickerStyle">@style/Widget.MyApp.DatePicker</item>
 * </style>
 * <p>
 * <style name="Widget.MyApp.DatePicker" parent="android:Widget.Material.DatePicker">
 * <item name="android:datePickerMode">spinner</item>
 * </style>
 * </resources>
 * <p>
 * May also pass DatePickerDialog.THEME_HOLO_LIGHT as an argument to the constructor,
 * as this theme has the DatePickerMode set to spinner.
 */
public class DatePickerDialogFixedNougatSpinner extends DatePickerDialog {

    public DatePickerDialogFixedNougatSpinner(Context context, OnDateSetListener listener, int year, int month, int dayOfMonth) {
        super(context, listener, year, month, dayOfMonth);
        fixSpinner(context, year, month, dayOfMonth);
    }

    public DatePickerDialogFixedNougatSpinner(Context context, int themeResId, OnDateSetListener listener, int year, int month, int dayOfMonth) {
        super(context, themeResId, listener, year, month, dayOfMonth);
        fixSpinner(context, year, month, dayOfMonth);
    }

    private void fixSpinner(Context context, int year, int month, int dayOfMonth) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            try {
                // Get the theme's android:datePickerMode
                final int MODE_SPINNER = 1;
                Class<?> styleableClass = Class.forName("com.android.internal.R$styleable");
                Field datePickerStyleableField = styleableClass.getField("DatePicker");
                int[] datePickerStyleable = (int[]) datePickerStyleableField.get(null);

                final TypedArray a = context.obtainStyledAttributes(null, datePickerStyleable, android.R.attr.datePickerStyle, 0);
                Field datePickerModeStyleableField = styleableClass.getField("DatePicker_datePickerMode");
                int datePickerModeStyleable = datePickerModeStyleableField.getInt(null);
                final int mode = a.getInt(datePickerModeStyleable, MODE_SPINNER);
                a.recycle();

                if (mode == MODE_SPINNER) {
                    DatePicker datePicker = (DatePicker) findField(DatePickerDialog.class, DatePicker.class, "mDatePicker").get(this);
                    Class<?> delegateClass = Class.forName("android.widget.DatePicker$DatePickerDelegate");
                    Field delegateField = findField(DatePicker.class, delegateClass, "mDelegate");
                    Object delegate = delegateField.get(datePicker);
                    Class<?> spinnerDelegateClass;
                    spinnerDelegateClass = Class.forName("android.widget.DatePickerSpinnerDelegate");

                    // In 7.0 Nougat for some reason the datePickerMode is ignored and the delegate is DatePickerClockDelegate
                    if (delegate.getClass() != spinnerDelegateClass) {
                        delegateField.set(datePicker, null); // throw out the DatePickerClockDelegate!
                        datePicker.removeAllViews(); // remove the DatePickerClockDelegate views
                        Method createSpinnerUIDelegate = DatePicker.class.getDeclaredMethod("createSpinnerUIDelegate", Context.class, AttributeSet.class, int.class, int.class);
                        createSpinnerUIDelegate.setAccessible(true);

                        // Instantiate a DatePickerSpinnerDelegate throughout createSpinnerUIDelegate method
                        delegate = createSpinnerUIDelegate.invoke(datePicker, context, null, android.R.attr.datePickerStyle, 0);
                        delegateField.set(datePicker, delegate); // set the DatePicker.mDelegate to the spinner delegate
                        // Initialize the date for the DatePicker delegate again
                        datePicker.init(year, month, dayOfMonth, this);
                    }
                }
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }
    }

    private static Field findField(Class objectClass, Class fieldClass, String expectedName) {
        try {
            Field field = objectClass.getDeclaredField(expectedName);
            field.setAccessible(true);
            return field;
        } catch (NoSuchFieldException e) {
        } // ignore
        // search for it if it wasn't found under the expected ivar name
        for (Field searchField : objectClass.getDeclaredFields()) {
            if (searchField.getType() == fieldClass) {
                searchField.setAccessible(true);
                return searchField;
            }
        }
        return null;
    }
}

TimePickerDialogFixedNougatSpinner.java

package my.packagename;

import android.app.TimePickerDialog;
import android.content.Context;
import android.content.res.TypedArray;
import android.os.Build;
import android.util.AttributeSet;
import android.widget.TimePicker;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;

/**
 * Workaround for this bug: https://code.google.com/p/android/issues/detail?id=222208
 * In Android 7.0 Nougat, spinner mode for the TimePicker in TimePickerDialog is
 * incorrectly displayed as clock, even when the theme specifies otherwise, such as:
 *
 *  <resources>
 *      <style name="Theme.MyApp" parent="Theme.AppCompat.Light.NoActionBar">
 *          <item name="android:timePickerStyle">@style/Widget.MyApp.TimePicker</item>
 *      </style>
 *
 *      <style name="Widget.MyApp.TimePicker" parent="android:Widget.Material.TimePicker">
 *          <item name="android:timePickerMode">spinner</item>
 *      </style>
 *  </resources>
 *
 * May also pass TimePickerDialog.THEME_HOLO_LIGHT as an argument to the constructor,
 * as this theme has the TimePickerMode set to spinner.
 */
public class TimePickerDialogFixedNougatSpinner extends TimePickerDialog {

    /**
     * Creates a new time picker dialog.
     *
     * @param context the parent context
     * @param listener the listener to call when the time is set
     * @param hourOfDay the initial hour
     * @param minute the initial minute
     * @param is24HourView whether this is a 24 hour view or AM/PM
     */
    public TimePickerDialogFixedNougatSpinner(Context context, OnTimeSetListener listener, int hourOfDay, int minute, boolean is24HourView) {

        super(context, listener, hourOfDay, minute, is24HourView);
        fixSpinner(context, hourOfDay, minute, is24HourView);
    }

    /**
     * Creates a new time picker dialog with the specified theme.
     *
     * @param context the parent context
     * @param themeResId the resource ID of the theme to apply to this dialog
     * @param listener the listener to call when the time is set
     * @param hourOfDay the initial hour
     * @param minute the initial minute
     * @param is24HourView Whether this is a 24 hour view, or AM/PM.
     */
    public TimePickerDialogFixedNougatSpinner(Context context, int themeResId, OnTimeSetListener listener, int hourOfDay, int minute, boolean is24HourView) {

        super(context, themeResId, listener, hourOfDay, minute, is24HourView);
        fixSpinner(context, hourOfDay, minute, is24HourView);
    }

    private void fixSpinner(Context context, int hourOfDay, int minute, boolean is24HourView) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) { // android:timePickerMode spinner and clock began in Lollipop
            try {
                // Get the theme's android:timePickerMode
                final int MODE_SPINNER = 1;
                Class<?> styleableClass = Class.forName("com.android.internal.R$styleable");
                Field timePickerStyleableField = styleableClass.getField("TimePicker");
                int[] timePickerStyleable = (int[]) timePickerStyleableField.get(null);
                final TypedArray a = context.obtainStyledAttributes(null, timePickerStyleable, android.R.attr.timePickerStyle, 0);
                Field timePickerModeStyleableField = styleableClass.getField("TimePicker_timePickerMode");
                int timePickerModeStyleable = timePickerModeStyleableField.getInt(null);
                final int mode = a.getInt(timePickerModeStyleable, MODE_SPINNER);
                a.recycle();
                if (mode == MODE_SPINNER) {
                    TimePicker timePicker = (TimePicker) findField(TimePickerDialog.class, TimePicker.class, "mTimePicker").get(this);
                    Class<?> delegateClass = Class.forName("android.widget.TimePicker$TimePickerDelegate");
                    Field delegateField = findField(TimePicker.class, delegateClass, "mDelegate");
                    Object delegate = delegateField.get(timePicker);
                    Class<?> spinnerDelegateClass;
                    if (Build.VERSION.SDK_INT != Build.VERSION_CODES.LOLLIPOP) {
                        spinnerDelegateClass = Class.forName("android.widget.TimePickerSpinnerDelegate");
                    } else {
                        // TimePickerSpinnerDelegate was initially misnamed TimePickerClockDelegate in API 21!
                        spinnerDelegateClass = Class.forName("android.widget.TimePickerClockDelegate");
                    }
                    // In 7.0 Nougat for some reason the timePickerMode is ignored and the delegate is TimePickerClockDelegate
                    if (delegate.getClass() != spinnerDelegateClass) {
                        delegateField.set(timePicker, null); // throw out the TimePickerClockDelegate!
                        timePicker.removeAllViews(); // remove the TimePickerClockDelegate views
                        Constructor spinnerDelegateConstructor = spinnerDelegateClass.getConstructor(TimePicker.class, Context.class, AttributeSet.class, int.class, int.class);
                        spinnerDelegateConstructor.setAccessible(true);
                        // Instantiate a TimePickerSpinnerDelegate
                        delegate = spinnerDelegateConstructor.newInstance(timePicker, context, null, android.R.attr.timePickerStyle, 0);
                        delegateField.set(timePicker, delegate); // set the TimePicker.mDelegate to the spinner delegate
                        // Set up the TimePicker again, with the TimePickerSpinnerDelegate
                        timePicker.setIs24HourView(is24HourView);
                        timePicker.setCurrentHour(hourOfDay);
                        timePicker.setCurrentMinute(minute);
                        timePicker.setOnTimeChangedListener(this);
                    }
                }
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }
    }

    private static Field findField(Class objectClass, Class fieldClass, String expectedName) {
        try {
            Field field = objectClass.getDeclaredField(expectedName);
            field.setAccessible(true);
            return field;
        } catch (NoSuchFieldException e) {} // ignore
        // search for it if it wasn't found under the expected ivar name
        for (Field searchField : objectClass.getDeclaredFields()) {
            if (searchField.getType() == fieldClass) {
                searchField.setAccessible(true);
                return searchField;
            }
        }
        return null;
    }
}