/* * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net) * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /** * * @ProjectName: $MiNotes$ * @Package: $ui$ * @ClassName: $DateTimePicker.java$ * @Description: 该类主要功能是实现设置闹钟过程中涉及时间变化部分的具体操作 * @Author: 石兆羲 * @CreateDate: $2023/12/25$ */ package net.micode.notes.ui; import java.text.DateFormatSymbols; import java.util.Calendar; import net.micode.notes.R; import android.content.Context; import android.text.format.DateFormat; import android.view.View; import android.widget.FrameLayout; import android.widget.NumberPicker; public class DateTimePicker extends FrameLayout { //FrameLayout是布局模板之一 //所有的子元素全部在屏幕的右上方 private static final boolean DEFAULT_ENABLE_STATE = true; private static final int HOURS_IN_HALF_DAY = 12; private static final int HOURS_IN_ALL_DAY = 24; private static final int DAYS_IN_ALL_WEEK = 7; private static final int DATE_SPINNER_MIN_VAL = 0; private static final int DATE_SPINNER_MAX_VAL = DAYS_IN_ALL_WEEK - 1; private static final int HOUR_SPINNER_MIN_VAL_24_HOUR_VIEW = 0; private static final int HOUR_SPINNER_MAX_VAL_24_HOUR_VIEW = 23; private static final int HOUR_SPINNER_MIN_VAL_12_HOUR_VIEW = 1; private static final int HOUR_SPINNER_MAX_VAL_12_HOUR_VIEW = 12; private static final int MINUT_SPINNER_MIN_VAL = 0; private static final int MINUT_SPINNER_MAX_VAL = 59; private static final int AMPM_SPINNER_MIN_VAL = 0; private static final int AMPM_SPINNER_MAX_VAL = 1; //以上语句的作用都是用于初始化控件 private final NumberPicker mDateSpinner; private final NumberPicker mHourSpinner; private final NumberPicker mMinuteSpinner; private final NumberPicker mAmPmSpinner; //NumberPicker是数字选择器，定义上述四个变量用于表示设置闹钟时需要选择的变量（时、分、秒、日期等） private Calendar mDate; //定义了Calendar类型的变量mDate，用于操作时间 private String[] mDateDisplayValues = new String[DAYS_IN_ALL_WEEK]; private boolean mIsAm; private boolean mIs24HourView; private boolean mIsEnabled = DEFAULT_ENABLE_STATE; private boolean mInitialising; private OnDateTimeChangedListener mOnDateTimeChangedListener; private NumberPicker.OnValueChangeListener mOnDateChangedListener = new NumberPicker.OnValueChangeListener() { @Override public void onValueChange(NumberPicker picker, int oldVal, int newVal) { mDate.add(Calendar.DAY_OF_YEAR, newVal - oldVal); updateDateControl(); //OnValueChangeListener，这是时间改变监听器，这里主要是对日期的监听 //将现在日期的值传递给mDate；updateDateControl是同步操作 onDateTimeChanged(); //这段代码是一个事件回调方法 onValueChange 的实现。它是在 NumberPicker 控件的值发生改变时被调用的。 //在这个方法中，首先根据新旧值的差异，使用 mDate.add(Calendar.DAY_OF_YEAR, newVal - oldVal) 方法来更新 mDate 对应的 Calendar 对象，即将日期增加或减少相应的天数。 //接下来，调用 updateDateControl() 方法来更新与日期相关的控件，更新显示日期的文本或者刷新界面等操作。 //最后，调用 onDateTimeChanged() 方法来处理日期时间的变化。 } }; private NumberPicker.OnValueChangeListener mOnHourChangedListener = new NumberPicker.OnValueChangeListener() { //这里是对 小时（Hour） 的监听 @Override public void onValueChange(NumberPicker picker, int oldVal, int newVal) { boolean isDateChanged = false; Calendar cal = Calendar.getInstance(); //声明一个Calendar的变量cal，便于后续的操作 if (!mIs24HourView) { if (!mIsAm && oldVal == HOURS_IN_HALF_DAY - 1 && newVal == HOURS_IN_HALF_DAY) { cal.setTimeInMillis(mDate.getTimeInMillis()); cal.add(Calendar.DAY_OF_YEAR, 1); isDateChanged = true; //这段代码是对于12小时制时，当从晚上的 11 点切换到早上的 12 点时，会将日期向后推一天。 } else if (mIsAm && oldVal == HOURS_IN_HALF_DAY && newVal == HOURS_IN_HALF_DAY - 1) { cal.setTimeInMillis(mDate.getTimeInMillis()); cal.add(Calendar.DAY_OF_YEAR, -1); isDateChanged = true; } //这段代码和之前的类似，但是是当从早上的 12 点切换到晚上的 11 点时，会将日期向前推一天。 if (oldVal == HOURS_IN_HALF_DAY - 1 && newVal == HOURS_IN_HALF_DAY || oldVal == HOURS_IN_HALF_DAY && newVal == HOURS_IN_HALF_DAY - 1) { mIsAm = !mIsAm; updateAmPmControl(); //当在凌晨 11 点和中午 12 点之间进行切换时，会切换上午和下午的状态，并更新相关的显示控件。 } } else { if (oldVal == HOURS_IN_ALL_DAY - 1 && newVal == 0) { cal.setTimeInMillis(mDate.getTimeInMillis()); cal.add(Calendar.DAY_OF_YEAR, 1); isDateChanged = true; //当从一天的最后一小时切换到第二天的第一小时时，会将日期向后推一天。 } else if (oldVal == 0 && newVal == HOURS_IN_ALL_DAY - 1) { cal.setTimeInMillis(mDate.getTimeInMillis()); cal.add(Calendar.DAY_OF_YEAR, -1); isDateChanged = true; //当从第二天的第一小时切换到一天的最后一小时时，会将日期向前推一天。 } } int newHour = mHourSpinner.getValue() % HOURS_IN_HALF_DAY + (mIsAm ? 0 : HOURS_IN_HALF_DAY); //通过数字选择器对newHour的赋值 mDate.set(Calendar.HOUR_OF_DAY, newHour); //通过set函数将新的Hour值传给mDate onDateTimeChanged(); if (isDateChanged) { setCurrentYear(cal.get(Calendar.YEAR)); setCurrentMonth(cal.get(Calendar.MONTH)); setCurrentDay(cal.get(Calendar.DAY_OF_MONTH)); }//这段代码是在日期发生变化时，将新的日期设置为当前的年月日。 } }; private NumberPicker.OnValueChangeListener mOnMinuteChangedListener = new NumberPicker.OnValueChangeListener() { @Override //对分钟（Minute）改变的监听 public void onValueChange(NumberPicker picker, int oldVal, int newVal) { int minValue = mMinuteSpinner.getMinValue(); int maxValue = mMinuteSpinner.getMaxValue(); //获取分钟数字选择器中的最大值和最小值 int offset = 0; //设置offset，作为小时改变的一个记录数据 if (oldVal == maxValue && newVal == minValue) { offset += 1; //如果原值为59，新值为0，则offset加1 } else if (oldVal == minValue && newVal == maxValue) { offset -= 1; //如果原值为0，新值为59，则offset减1 } if (offset != 0) { //如果 offset 不等于 0，表示需要进行偏移操作。接下来的代码会根据偏移值更新日期和小时的值。 mDate.add(Calendar.HOUR_OF_DAY, offset);//偏移日期，将小时增加或减少。 mHourSpinner.setValue(getCurrentHour());//小时的选择器设置为当前的小时值。 updateDateControl();//更新日期相关的显示控件。 int newHour = getCurrentHourOfDay(); if (newHour >= HOURS_IN_HALF_DAY) { mIsAm = false; updateAmPmControl(); } else { mIsAm = true; updateAmPmControl(); }//根据 newHour 的值判断是否超过半天。若超过半天，则将 mIsAm 设置为 false，否则设置为 true。 //然后调用 updateAmPmControl() 更新上午/下午的显示控件。 } mDate.set(Calendar.MINUTE, newVal);//将选择器中的分钟值设置为 newVal，即新选择的分钟值。 onDateTimeChanged(); } }; private NumberPicker.OnValueChangeListener mOnAmPmChangedListener = new NumberPicker.OnValueChangeListener() { //对AM和PM的监听 @Override public void onValueChange(NumberPicker picker, int oldVal, int newVal) {//是在上午/下午选择器的值发生变化时的处理逻辑。 mIsAm = !mIsAm; if (mIsAm) {//如果 mIsAm 是 true，表示用户选择了上午。前调12小时 mDate.add(Calendar.HOUR_OF_DAY, -HOURS_IN_HALF_DAY); } else {//如果 mIsAm 是 false，表示用户选择了下午。后调12小时 mDate.add(Calendar.HOUR_OF_DAY, HOURS_IN_HALF_DAY); } updateAmPmControl();//更新上/下午显示控件 onDateTimeChanged(); } }; public interface OnDateTimeChangedListener { //用来监听日期选择器的变化。 void onDateTimeChanged(DateTimePicker view, int year, int month, int dayOfMonth, int hourOfDay, int minute); /*view：表示触发事件的日期时间选择器。 year：表示选择的年份。 month：表示选择的月份，范围是 0-11（0 表示一月）。 dayOfMonth：表示选择的日期。 hourOfDay：表示选择的小时数，范围是 0-23。 minute：表示选择的分钟数，范围是 0-59。*/ } public DateTimePicker(Context context) { this(context, System.currentTimeMillis()); //通过对数据库的访问，获取当前的系统时间 } public DateTimePicker(Context context, long date) { this(context, date, DateFormat.is24HourFormat(context)); }//上面函数的得到的是一个天文数字（1970至今的秒数），需要DateFormat将其变得有意义 public DateTimePicker(Context context, long date, boolean is24HourView) { super(context); //获取系统时间 mDate = Calendar.getInstance(); mInitialising = true; mIsAm = getCurrentHourOfDay() >= HOURS_IN_HALF_DAY; inflate(context, R.layout.datetime_picker, this); //如果当前Activity里用到别的layout，比如对话框layout //还要设置这个layout上的其他组件的内容，就必须用inflate()方法先将对话框的layout找出来 //然后再用findViewById()找到它上面的其它组件 mDateSpinner = (NumberPicker) findViewById(R.id.date); mDateSpinner.setMinValue(DATE_SPINNER_MIN_VAL); mDateSpinner.setMaxValue(DATE_SPINNER_MAX_VAL); mDateSpinner.setOnValueChangedListener(mOnDateChangedListener); mHourSpinner = (NumberPicker) findViewById(R.id.hour); mHourSpinner.setOnValueChangedListener(mOnHourChangedListener); mMinuteSpinner = (NumberPicker) findViewById(R.id.minute); mMinuteSpinner.setMinValue(MINUT_SPINNER_MIN_VAL); mMinuteSpinner.setMaxValue(MINUT_SPINNER_MAX_VAL); mMinuteSpinner.setOnLongPressUpdateInterval(100); mMinuteSpinner.setOnValueChangedListener(mOnMinuteChangedListener); String[] stringsForAmPm = new DateFormatSymbols().getAmPmStrings(); mAmPmSpinner = (NumberPicker) findViewById(R.id.amPm); mAmPmSpinner.setMinValue(AMPM_SPINNER_MIN_VAL); mAmPmSpinner.setMaxValue(AMPM_SPINNER_MAX_VAL); mAmPmSpinner.setDisplayedValues(stringsForAmPm); mAmPmSpinner.setOnValueChangedListener(mOnAmPmChangedListener); //可以看到原有的注释，意思是初始化日期时间选择器中的三个数字选择器和一个上午/下午选择器。 // update controls to initial state updateDateControl(); updateHourControl(); updateAmPmControl(); set24HourView(is24HourView); //设置当前时间 // set to current time setCurrentDate(date); setEnabled(isEnabled()); //设置内容描述（目的是提高访问性） // set the content descriptions mInitialising = false; } @Override public void setEnabled(boolean enabled) { if (mIsEnabled == enabled) { return; } super.setEnabled(enabled); mDateSpinner.setEnabled(enabled); mMinuteSpinner.setEnabled(enabled); mHourSpinner.setEnabled(enabled); mAmPmSpinner.setEnabled(enabled); mIsEnabled = enabled; }//这段代码定义了一个名为 setEnabled() 的方法，用于启用或禁用日期时间选择器。 @Override public boolean isEnabled() { return mIsEnabled; } /** * Get the current date in millis * * @return the current date in millis */ public long getCurrentDateInTimeMillis() { return mDate.getTimeInMillis(); }//得到当前秒数 /** * Set the current date * * @param date The current date in millis */ public void setCurrentDate(long date) { Calendar cal = Calendar.getInstance(); cal.setTimeInMillis(date); setCurrentDate(cal.get(Calendar.YEAR), cal.get(Calendar.MONTH), cal.get(Calendar.DAY_OF_MONTH), cal.get(Calendar.HOUR_OF_DAY), cal.get(Calendar.MINUTE)); }//设置当前时间，参数date /** * Set the current date * * @param year The current year * @param month The current month * @param dayOfMonth The current dayOfMonth * @param hourOfDay The current hourOfDay * @param minute The current minute */ public void setCurrentDate(int year, int month, int dayOfMonth, int hourOfDay, int minute) { setCurrentYear(year); setCurrentMonth(month); setCurrentDay(dayOfMonth); setCurrentHour(hourOfDay); setCurrentMinute(minute); }//设置当前时间 /** * Get current year * * @return The current year */ public int getCurrentYear() { return mDate.get(Calendar.YEAR); } /** * Set current year * * @param year The current year */ public void setCurrentYear(int year) { if (!mInitialising && year == getCurrentYear()) { return; } mDate.set(Calendar.YEAR, year); updateDateControl(); onDateTimeChanged(); } /** * Get current month in the year * * @return The current month in the year */ public int getCurrentMonth() { return mDate.get(Calendar.MONTH); } /** * Set current month in the year * * @param month The month in the year */ public void setCurrentMonth(int month) { if (!mInitialising && month == getCurrentMonth()) { return; } mDate.set(Calendar.MONTH, month); updateDateControl(); onDateTimeChanged(); } /** * Get current day of the month * * @return The day of the month */ public int getCurrentDay() { return mDate.get(Calendar.DAY_OF_MONTH); } /** * Set current day of the month * * @param dayOfMonth The day of the month */ public void setCurrentDay(int dayOfMonth) { if (!mInitialising && dayOfMonth == getCurrentDay()) { return; } mDate.set(Calendar.DAY_OF_MONTH, dayOfMonth); updateDateControl(); onDateTimeChanged(); } //上述一大段代码实现的功能是得到year、month、day等值 /** * Get current hour in 24 hour mode, in the range (0~23) * @return The current hour in 24 hour mode */ public int getCurrentHourOfDay() { return mDate.get(Calendar.HOUR_OF_DAY); } private int getCurrentHour() { if (mIs24HourView){ return getCurrentHourOfDay(); } else { int hour = getCurrentHourOfDay(); if (hour > HOURS_IN_HALF_DAY) { return hour - HOURS_IN_HALF_DAY; } else { return hour == 0 ? HOURS_IN_HALF_DAY : hour; } } } /** * Set current hour in 24 hour mode, in the range (0~23) * * @param hourOfDay */ public void setCurrentHour(int hourOfDay) { if (!mInitialising && hourOfDay == getCurrentHourOfDay()) { return; } mDate.set(Calendar.HOUR_OF_DAY, hourOfDay); if (!mIs24HourView) { if (hourOfDay >= HOURS_IN_HALF_DAY) { mIsAm = false; if (hourOfDay > HOURS_IN_HALF_DAY) { hourOfDay -= HOURS_IN_HALF_DAY; } } else { mIsAm = true; if (hourOfDay == 0) { hourOfDay = HOURS_IN_HALF_DAY; } } updateAmPmControl(); } mHourSpinner.setValue(hourOfDay); onDateTimeChanged(); } /** * Get currentMinute * * @return The Current Minute */ public int getCurrentMinute() { return mDate.get(Calendar.MINUTE); } /** * Set current minute */ public void setCurrentMinute(int minute) { if (!mInitialising && minute == getCurrentMinute()) { return; } mMinuteSpinner.setValue(minute); mDate.set(Calendar.MINUTE, minute); onDateTimeChanged(); } /** * @return true if this is in 24 hour view else false. */ public boolean is24HourView () { return mIs24HourView; } /** * Set whether in 24 hour or AM/PM mode. * * @param is24HourView True for 24 hour mode. False for AM/PM mode. */ public void set24HourView(boolean is24HourView) { if (mIs24HourView == is24HourView) { return; } mIs24HourView = is24HourView; mAmPmSpinner.setVisibility(is24HourView ? View.GONE : View.VISIBLE); int hour = getCurrentHourOfDay(); updateHourControl(); setCurrentHour(hour); updateAmPmControl(); } private void updateDateControl() { Calendar cal = Calendar.getInstance(); cal.setTimeInMillis(mDate.getTimeInMillis()); cal.add(Calendar.DAY_OF_YEAR, -DAYS_IN_ALL_WEEK / 2 - 1); mDateSpinner.setDisplayedValues(null); for (int i = 0; i < DAYS_IN_ALL_WEEK; ++i) { cal.add(Calendar.DAY_OF_YEAR, 1); mDateDisplayValues[i] = (String) DateFormat.format("MM.dd EEEE", cal); } mDateSpinner.setDisplayedValues(mDateDisplayValues); mDateSpinner.setValue(DAYS_IN_ALL_WEEK / 2); mDateSpinner.invalidate(); }//一个关于星期几的算法 private void updateAmPmControl() { if (mIs24HourView) { mAmPmSpinner.setVisibility(View.GONE); } else { int index = mIsAm ? Calendar.AM : Calendar.PM; mAmPmSpinner.setValue(index); mAmPmSpinner.setVisibility(View.VISIBLE); } }//判断上午下午的算法 private void updateHourControl() { if (mIs24HourView) { mHourSpinner.setMinValue(HOUR_SPINNER_MIN_VAL_24_HOUR_VIEW); mHourSpinner.setMaxValue(HOUR_SPINNER_MAX_VAL_24_HOUR_VIEW); } else { mHourSpinner.setMinValue(HOUR_SPINNER_MIN_VAL_12_HOUR_VIEW); mHourSpinner.setMaxValue(HOUR_SPINNER_MAX_VAL_12_HOUR_VIEW); }//小时的算法 } /** * Set the callback that indicates the 'Set' button has been pressed. * @param callback the callback, if null will do nothing */ public void setOnDateTimeChangedListener(OnDateTimeChangedListener callback) { mOnDateTimeChangedListener = callback; } private void onDateTimeChanged() { if (mOnDateTimeChangedListener != null) { mOnDateTimeChangedListener.onDateTimeChanged(this, getCurrentYear(), getCurrentMonth(), getCurrentDay(), getCurrentHourOfDay(), getCurrentMinute()); } } }