Android 8.1 Launcher3实现动态指针时钟功能

本文主要实现功能，可能有不合理的地方

首先创建一个实现功能的工具里，直接上代码：

import android.content.Context;
import android.graphics.Bitmap;
import android.os.Handler;
import android.os.Message;
import com.android.launcher3.ItemInfo;
import com.android.launcher3.LauncherSettings;
import com.android.launcher3.ShortcutInfo;
import com.android.launcher3.util.LogUtil;
public class DeskClockUtil {
 private OnDeskClockIconChangeListener mListener;
 private ItemInfo mItemInfo;
 private boolean mIsResume;
 private Handler mHandler = new Handler() {
   @Override
   public void handleMessage(Message msg) {
     super.handleMessage(msg);
     if (msg.what == 100) {
       Message msg1 = new Message();
       msg1.what = 100;
       msg1.obj = msg.obj;
       mHandler.sendMessageDelayed(msg1, 60000);
       if (mListener != null && mItemInfo != null) {
         mListener.onChange(IconUtil.getDeskClockIcon((Context) msg.obj), mItemInfo);
       }
     }
   }
 };
 private static DeskClockUtil sInstance;
 private DeskClockUtil() {
 }
 public static DeskClockUtil getInstance() {
   if (sInstance == null) {
     sInstance = new DeskClockUtil();
   }
   return sInstance;
 }
 private void refresh(Context context) {
   if (mListener != null && mItemInfo != null) {
     mListener.onChange(IconUtil.getDeskClockIcon(context), mItemInfo);
   }
   if (mHandler.hasMessages(100)) {
     mHandler.removeMessages(100);
   }
   Message msg = new Message();
   msg.what = 100;
   msg.obj = context;
   mHandler.sendMessageDelayed(msg,
       1000 * (60 - Integer.parseInt(DateUtils.getCurrentSecond())));
 }
 public void onResume(Context context) {
   mIsResume = true;
   refresh(context);
 }
 public void onPause() {
   mIsResume = false;
   mHandler.removeMessages(100);
 }
 public void setListener(OnDeskClockIconChangeListener listener, ItemInfo info, Context context) {
   if (!(info instanceof ShortcutInfo)) {
     return;
   }
   String pkg = null;
   if (info.getIntent() != null && info.getIntent().getComponent() != null) {
     pkg = info.getIntent().getComponent().getPackageName();
   }
   if (!"com.android.deskclock".equals(pkg) || info.itemType == LauncherSettings.Favorites.ITEM_TYPE_DEEP_SHORTCUT) {
     return;
   }
   mListener = listener;
   mItemInfo = info;
   if (mIsResume) {
     refresh(context);
   }
 }
 public interface OnDeskClockIconChangeListener {
   void onChange(Bitmap icon, ItemInfo info);
 }
}

画出动态时钟

import android.content.Context;
import android.graphics.*;
import com.android.launcher3.R;
public class IconUtil {
 private static final String TAG = "IconUtil";
 private static Bitmap getBitmap(Context context, int res) {
   BitmapFactory.Options options = new BitmapFactory.Options();
   options.inPreferredConfig = Bitmap.Config.ARGB_4444;
   return BitmapFactory.decodeResource(context.getResources(), res, options);
 }
 public static Bitmap getDeskClockIcon(Context context) {
   // 添加一个带表盘的背景图
   Bitmap empty = getBitmap(context, R.drawable.icon_time);
   int x = empty.getWidth();
   int y = empty.getHeight();
   Bitmap deskClock = Bitmap.createBitmap(x, y, Bitmap.Config.ARGB_4444);
   Canvas canvas = new Canvas(deskClock);
   Paint paint = new Paint();
   paint.setAntiAlias(true);
   canvas.drawBitmap(empty, 0, 0, paint);
   //设置圆角
   paint.setStrokeCap(Paint.Cap.ROUND);
   paint.setStrokeWidth(5);
   paint.setColor(context.getResources().getColor(R.color.deskclock_time));
   // 时针的长度
   int radius = 35;
   // 圆心的x y 坐标
   int cx = x / 2;
   int cy = y / 2;
   int hour = Integer.parseInt(DateUtils.getCurrentHour());
   int min = Integer.parseInt(DateUtils.getCurrentMin());
   //时针的角度，这里是整点的角度。因为0°是从3点开始，所以这里减90°，从9点开始计算角度
   int drgeeHour = hour * 30 - 90;
   if (drgeeHour < 0) {
     drgeeHour += 360;
   }
   // 加上时针在两个整点之间的角度，一分钟在分针上是6°，在时针上是min * 6 / 12
   drgeeHour += min * 6 / 12;
   //时针 针尖的x y坐标，相当于已知圆心坐标和半径，求圆上任意一点的坐标
   int xHour = (int) (cx + radius * Math.cos(drgeeHour * 3.14 / 180));
   int yHour = (int) (cy + radius * Math.sin(drgeeHour * 3.14 / 180));
   canvas.drawLine(xHour, yHour, cx, cy, paint);
   //分针的长度
   radius = 45;
   paint.setStrokeWidth(3);
   paint.setColor(Color.RED);
   //分针的角度
   int drgeeMin = min * 6 - 90;
   if (drgeeMin < 0) {
     drgeeMin += 360;
   }
   //分针 针尖的x y坐标
   int x1 = (int) (cx + radius * Math.cos(drgeeMin * Math.PI / 180));
   int y1 = (int) (cy + radius * Math.sin(drgeeMin * Math.PI / 180));
   canvas.drawLine(x1, y1, cx, cy, paint);
   return deskClock;
 }
}

时间工具类

import java.text.SimpleDateFormat;
public class DateUtils {
 public static String getCurrentDay() {
   SimpleDateFormat format = new SimpleDateFormat("dd");
   Long t = new Long(System.currentTimeMillis());
   String d = format.format(t);
   return d;
 }
 public static String getCurrentSecond() {
   SimpleDateFormat format = new SimpleDateFormat("ss");
   Long t = new Long(System.currentTimeMillis());
   String d = format.format(t);
   return d;
 }
 public static String getCurrentMin() {
   SimpleDateFormat format = new SimpleDateFormat("mm");
   Long t = new Long(System.currentTimeMillis());
   String d = format.format(t);
   return d;
 }
 public static String getCurrentHour() {
   SimpleDateFormat format = new SimpleDateFormat("HH");
   Long t = new Long(System.currentTimeMillis());
   String d = format.format(t);
   return d;
 }
}

下面就比较简单了，我是在BubbleTextView.java中添加listener，我这里偷懒了，应该给时钟单独创建一个view，继承BubbleTextView。

private void applyIconAndLabel(Bitmap icon, ItemInfo info) {
   /* begin */
   setDeskClockIcon(info);
   /* end */
   applyIcon(icon, info);
   setText(info.title);
   if (info.contentDescription != null) {
     setContentDescription(info.isDisabled()
         ? getContext().getString(R.string.disabled_app_label, info.contentDescription)
         : info.contentDescription);
   }
 }
 private void setDeskClockIcon(ItemInfo info) {
   DeskClockUtil.getInstance().setListener(new DeskClockUtil.OnDeskClockIconChangeListener() {
     @Override
     public void onChange(Bitmap icon, ItemInfo info) {
       applyIcon(icon, info);
     }
   }, info, getContext());
 }
 private void applyIcon(Bitmap icon, ItemInfo info) {
   FastBitmapDrawable iconDrawable = DrawableFactory.get(getContext()).newIcon(icon, info);
   iconDrawable.setIsDisabled(info.isDisabled());
   setIcon(iconDrawable);
 }

在Launcher.java的onResume()和onPause()中分别开始和暂停

@Override  protected void onResume() {
  ......
   /* begin */
   DeskClockUtil.getInstance().onResume(this);
   /* end */
   if (mLauncherCallbacks != null) {
     mLauncherCallbacks.onResume();
   }
 }

@Override
 protected void onPause() {
   // Ensure that items added to Launcher are queued until Launcher returns
   InstallShortcutReceiver.enableInstallQueue(InstallShortcutReceiver.FLAG_ACTIVITY_PAUSED);
   super.onPause();
   mPaused = true;
   mDragController.cancelDrag();
   mDragController.resetLastGestureUpTime();
   // We call onHide() aggressively. The custom content callbacks should be able to
   // debounce excess onHide calls.
   if (mWorkspace.getCustomContentCallbacks() != null) {
     mWorkspace.getCustomContentCallbacks().onHide();
   }
   if (mLauncherCallbacks != null) {
     mLauncherCallbacks.onPause();
   }
   /* begin */
   DeskClockUtil.getInstance().onPause();
   /* end */
 }

这样就可以了，如果想要加秒针，在IconUtil中再把秒针画出来就行。
 还有日历的动态图标也可以用同样的方法实现

总结

以上所述是小编给大家介绍的Android 8.1 Launcher3实现动态指针时钟功能网站的支持！

来源：https://blog.csdn.net/qq_30552095/article/details/81021625