问自定义首选项，Target tSdkVersion=“11”：缺少缩进如何处理？

package apt.tutorial;

import android.content.Context;
import android.content.res.TypedArray;
import android.os.Bundle;
import android.os.Parcel;
import android.os.Parcelable;
import android.preference.DialogPreference;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewParent;
import android.widget.TimePicker;

public class TimePreference extends DialogPreference {
    private int lastHour=0;
    private int lastMinute=0;
    private TimePicker picker=null;

    public static int getHour(String time) {
        String[] pieces=time.split(":");

        return(Integer.parseInt(pieces[0]));
    }

    public static int getMinute(String time) {
        String[] pieces=time.split(":");

        return(Integer.parseInt(pieces[1]));
    }

    public TimePreference(Context ctxt) {
        this(ctxt, null);
    }

    public TimePreference(Context ctxt, AttributeSet attrs) {
        this(ctxt, attrs, 0);
    }

    public TimePreference(Context ctxt, AttributeSet attrs, int defStyle) {
        super(ctxt, attrs, defStyle);

        setPositiveButtonText("Set");
        setNegativeButtonText("Cancel");
    }

    @Override
    protected View onCreateDialogView() {
        picker=new TimePicker(getContext());

        return(picker);
    }

    @Override
    protected void onBindDialogView(View v) {
        super.onBindDialogView(v);

        picker.setCurrentHour(lastHour);
        picker.setCurrentMinute(lastMinute);
    }

    @Override
    protected void onDialogClosed(boolean positiveResult) {
        super.onDialogClosed(positiveResult);

        if (positiveResult) {
            lastHour=picker.getCurrentHour();
            lastMinute=picker.getCurrentMinute();

            String time=String.valueOf(lastHour)+":"+String.valueOf(lastMinute);

            if (callChangeListener(time)) {
                persistString(time);
            }
        }
    }

    @Override
    protected Object onGetDefaultValue(TypedArray a, int index) {
        return(a.getString(index));
    }

    @Override
    protected void onSetInitialValue(boolean restoreValue, Object defaultValue) {
        String time=null;

        if (restoreValue) {
            if (defaultValue==null) {
                time=getPersistedString("00:00");
            }
            else {
                time=getPersistedString(defaultValue.toString());
            }
        }
        else {
            time=defaultValue.toString();
        }

        lastHour=getHour(time);
        lastMinute=getMinute(time);
    }
}

<PreferenceScreen
    xmlns:android="http://schemas.android.com/apk/res/android">
    <ListPreference
        android:key="sort_order"
        android:title="Sort Order"
        android:summary="Choose the order the list uses"
        android:entries="@array/sort_names"
        android:entryValues="@array/sort_clauses"
        android:dialogTitle="Choose a sort order" />
    <CheckBoxPreference
        android:key="alarm"
        android:title="Sound a Lunch Alarm"
        android:summary="Check if you want to know when it is time for lunch" />
    <apt.tutorial.TimePreference
        android:key="alarm_time"
        android:title="Lunch Alarm Time"
        android:defaultValue="12:00"
        android:summary="Set your desired time for the lunch alarm"
        android:dependency="alarm" />
    <CheckBoxPreference
        android:key="use_notification"
        android:title="Use a Notification"
        android:defaultValue="true"
        android:summary="Check if you want a status bar icon at lunchtime, or uncheck for a full-screen notice"
        android:dependency="alarm" />
</PreferenceScreen>