先来看一张动态图
昨天跟着视频学了如何自定义View并做成仿360悬浮球与加速球的样式
可以看出来，做成的效果有：
- 点击按钮后退出Activity，呈现一个圆形的悬浮球，可以随意拖动并会自动依靠到屏幕一侧，且拖动时会变成一张图片
- 当点击悬浮球时，悬浮球隐藏，底部出现一个加速球，双击加速球时，呈现水量逐渐增高且波动幅度较小的效果，单击时波浪上下波动且幅度渐小
- 点击屏幕不包含底部加速球的部位，加速球会隐藏，悬浮球重新出现
要做出这么一个效果，需要两个自定义View与一个自定义ViewGroup
首先，需要先设计悬浮球View——FloatBall
简单起见，为FloatBall指定一个默认宽度和高度——150像素
然后在onDraw(Canvas canvas)方法中，判断FloatBall是否正在被拖动isDrag，如果是，则绘制一张默认图片bitmap，否则则根据绘图函数绘制圆形与居中文本
/**
* Created by ZY on 2016/8/10.
* 悬浮球
*/
public class FloatBall extends View {
public int width = 150;
public int height = 150;
//默认显示的文本
private String text = "50%";
//是否在拖动
private boolean isDrag;
private Paint ballPaint;
private Paint textPaint;
private Bitmap bitmap;
public FloatBall(Context context) {
super(context);
init();
}
public FloatBall(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public FloatBall(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
public void init() {
ballPaint = new Paint();
ballPaint.setColor(Color.GRAY);
ballPaint.setAntiAlias(true);
textPaint = new Paint();
textPaint.setTextSize(25);
textPaint.setColor(Color.WHITE);
textPaint.setAntiAlias(true);
textPaint.setFakeBoldText(true);
Bitmap src = BitmapFactory.decodeResource(getResources(), R.drawable.ninja);
//将图片裁剪到指定大小
bitmap = Bitmap.createScaledBitmap(src, width, height, true);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
setMeasuredDimension(width, height);
}
@Override
protected void onDraw(Canvas canvas) {
if (!isDrag) {
canvas.drawCircle(width / 2, height / 2, width / 2, ballPaint);
float textWidth = textPaint.measureText(text);
Paint.FontMetrics fontMetrics = textPaint.getFontMetrics();
float dy = -(fontMetrics.descent + fontMetrics.ascent) / 2;
canvas.drawText(text, width / 2 - textWidth / 2, height / 2 + dy, textPaint);
} else {
//正在被拖动时则显示指定图片
canvas.drawBitmap(bitmap, 0, 0, null);
}
}
//设置当前移动状态
public void setDragState(boolean isDrag) {
this.isDrag = isDrag;
invalidate();
}
}
因为FloatBall是不存在于Activity中而在屏幕单独显示的，所以需要用WindowManager来添加View并显示
新建一个类，命名为ViewManager，用来总的管理View的显示与删除
私有化构造函数并采用单例模式
private static ViewManager manager;
//私有化构造函数
private ViewManager(Context context) {
this.context = context;
init();
}
//获取ViewManager实例
public static ViewManager getInstance(Context context) {
if (manager == null) {
manager = new ViewManager(context);
}
return manager;
}
ViewManager包含有显示与隐藏悬浮球与加速球的函数
//显示浮动小球
public void showFloatBall() {
if (floatBallParams == null) {
floatBallParams = new LayoutParams();
floatBallParams.width = floatBall.width;
floatBallParams.height = floatBall.height - getStatusHeight();
floatBallParams.gravity = Gravity.TOP | Gravity.LEFT;
floatBallParams.type = LayoutParams.TYPE_TOAST;
floatBallParams.flags = LayoutParams.FLAG_NOT_FOCUSABLE | LayoutParams.FLAG_NOT_TOUCH_MODAL;
floatBallParams.format = PixelFormat.RGBA_8888;
}
windowManager.addView(floatBall, floatBallParams);
}
//显示底部菜单
private void showFloatMenu() {
if (floatMenuParams == null) {
floatMenuParams = new LayoutParams();
floatMenuParams.width = getScreenWidth();
floatMenuParams.height = getScreenHeight() - getStatusHeight();
floatMenuParams.gravity = Gravity.BOTTOM;
floatMenuParams.type = LayoutParams.TYPE_TOAST;
floatMenuParams.flags = LayoutParams.FLAG_NOT_FOCUSABLE | LayoutParams.FLAG_NOT_TOUCH_MODAL;
floatMenuParams.format = PixelFormat.RGBA_8888;
}
windowManager.addView(floatMenu, floatMenuParams);
}
//隐藏底部菜单
public void hideFloatMenu() {
if (floatMenu != null) {
windowManager.removeView(floatMenu);
}
}
将悬浮球置于Service中开启，这样悬浮球就不那么容易被系统去除了
在onCreate()方法中调用showFloatBall()
public class StartFloatBallService extends Service {
public StartFloatBallService() {
}
@Override
public IBinder onBind(Intent intent) {
// TODO: Return the communication channel to the service.
throw new UnsupportedOperationException("Not yet implemented");
}
@Override
public void onCreate() {
ViewManager manager = ViewManager.getInstance(this);
manager.showFloatBall();
super.onCreate();
}
}
此时，只要为MainActivity添加一个按钮，并设定当点击按钮后开启Service，此时即可看到屏幕显示了一个悬浮球
public void startService(View view) {
Intent intent = new Intent(this, StartFloatBallService.class);
startService(intent);
finish();
}
不过此时悬浮球还不支持拖动与点击，还需要为其添加OnTouchListener与OnClickListener
View.OnTouchListener touchListener = new View.OnTouchListener() {
float startX;
float startY;
float tempX;
float tempY;
@Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
startX = event.getRawX();
startY = event.getRawY();
tempX = event.getRawX();
tempY = event.getRawY();
break;
case MotionEvent.ACTION_MOVE:
float x = event.getRawX() - startX;
float y = event.getRawY() - startY;
//计算偏移量，刷新视图
floatBallParams.x += x;
floatBallParams.y += y;
floatBall.setDragState(true);
windowManager.updateViewLayout(floatBall, floatBallParams);
startX = event.getRawX();
startY = event.getRawY();
break;
case MotionEvent.ACTION_UP:
//判断松手时View的横坐标是靠近屏幕哪一侧，将View移动到依靠屏幕
float endX = event.getRawX();
float endY = event.getRawY();
if (endX < getScreenWidth() / 2) {
endX = 0;
} else {
endX = getScreenWidth() - floatBall.width;
}
floatBallParams.x = (int) endX;
floatBall.setDragState(false);
windowManager.updateViewLayout(floatBall, floatBallParams);
//如果初始落点与松手落点的坐标差值超过6个像素，则拦截该点击事件
//否则继续传递，将事件交给OnClickListener函数处理
if (Math.abs(endX - tempX) > 6 && Math.abs(endY - tempY) > 6) {
return true;
}
break;
}
return false;
}
};
OnClickListener clickListener = new OnClickListener() {
@Override
public void onClick(View v) {
windowManager.removeView(floatBall);
showFloatMenu();
floatMenu.startAnimation();
}
};
floatBall.setOnTouchListener(touchListener);
floatBall.setOnClickListener(clickListener);
加速球ProgressBall的设计较为复杂，需要用到贝塞尔曲线来呈现波浪效果，且单击双击的效果也需要分开呈现
同样是让ProgressBall继承于View
进度值的意义在于限制水面最终上升到的高度，即根据目标进度值与最大进度值的比例来决定水面高度
波浪总的起伏次数Count用于在单击加速球时，水面上下波动的次数
//view的宽度
private int width = 200;
//view的高度
private int height = 200;
//最大进度值
private final int maxProgress = 100;
//当前进度值
private int currentProgress = 0;
//目标进度值
private final int targetProgress = 70;
//是否为单击
private boolean isSingleTop;
//设定波浪总的起伏次数
private final int Count = 20;
//当前起伏次数
private int currentCount;
//初始振幅大小
private final int startAmplitude = 15;
//波浪周期性出现的次数
private final int cycleCount = width / (startAmplitude * 4) + 1;
初始化画笔与监听函数
private void init() {
//初始化小球画笔
ballPaint = new Paint();
ballPaint.setAntiAlias(true);
ballPaint.setColor(Color.argb(0xff, 0x3a, 0x8c, 0x6c));
//初始化（波浪）进度条画笔
progressPaint = new Paint();
progressPaint.setAntiAlias(true);
progressPaint.setColor(Color.argb(0xff, 0x4e, 0xc9, 0x63));
progressPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
//初始化文字画笔
textPaint = new Paint();
textPaint.setAntiAlias(true);
textPaint.setColor(Color.WHITE);
textPaint.setTextSize(25);
handler = new Handler();
path = new Path();
bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
bitmapCanvas = new Canvas(bitmap);
//手势监听
//重点在于将单击和双击操作分隔开
SimpleOnGestureListener listener = new SimpleOnGestureListener() {
//双击
@Override
public boolean onDoubleTap(MotionEvent e) {
//当前波浪起伏次数为零，说明“单击效果”没有影响到现在
if (currentCount == 0) {
//当前进度为零或者已达到目标进度值，说明“双击效果”没有影响到现在，此时可以允许进行双击操作
if (currentProgress == 0 || currentProgress == targetProgress) {
currentProgress = 0;
isSingleTop = false;
startDoubleTapAnimation();
}
}
return super.onDoubleTap(e);
}
//单击
@Override
public boolean onSingleTapConfirmed(MotionEvent e) {
//当前进度值等于目标进度值，且当前波动次数为零，则允许进行单击操作
if (currentProgress == targetProgress && currentCount == 0) {
isSingleTop = true;
startSingleTapAnimation();
}
return super.onSingleTapConfirmed(e);
}
};
gestureDetector = new GestureDetector(context, listener);
setOnTouchListener(new OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
return gestureDetector.onTouchEvent(event);
}
});
//接受点击操作
setClickable(true);
}
单击或双击后的渐变效果是利用Handler的postDelayed(Runnable r, long delayMillis)方法来实现的，可以设定一个延时时间去执行Runnable ，然后在Runnable 中再次调用自身
class DoubleTapRunnable implements Runnable {
@Override
public void run() {
if (currentProgress < targetProgress) {
invalidate();
handler.postDelayed(doubleTapRunnable, 50);
currentProgress++;
} else {
handler.removeCallbacks(doubleTapRunnable);
}
}
}
//开启双击动作动画
public void startDoubleTapAnimation() {
handler.postDelayed(doubleTapRunnable, 50);
}
class SingleTapRunnable implements Runnable {
@Override
public void run() {
if (currentCount < Count) {
invalidate();
currentCount++;
handler.postDelayed(singleTapRunnable, 100);
} else {
handler.removeCallbacks(singleTapRunnable);
currentCount = 0;
}
}
}
//开启单击动作动画
public void startSingleTapAnimation() {
handler.postDelayed(singleTapRunnable, 100);
}
onDraw(Canvas canvas)的重点在于根据比例值来计算水面高度
@Override
protected void onDraw(Canvas canvas) {
//绘制圆形
bitmapCanvas.drawCircle(width / 2, height / 2, width / 2, ballPaint);
path.reset();
//高度随当前进度值的变化而变化
float y = (1 - (float) currentProgress / maxProgress) * height;
//属性PorterDuff.Mode.SRC_IN代表了progressPaint只显示与下层层叠的部分，
//所以以下四点虽然连起来是个矩形，可呈现出来的依然是圆形
//右上角
path.moveTo(width, y);
//右下角
path.lineTo(width, height);
//左下角
path.lineTo(0, height);
//左上角
path.lineTo(0, y);
//绘制顶部波浪
if (!isSingleTop) {
//是双击
//根据当前进度大小调整振幅大小，有逐渐减小的趋势
float tempAmplitude = (1 - (float) currentProgress / targetProgress) * startAmplitude;
for (int i = 0; i < cycleCount; i++) {
path.rQuadTo(startAmplitude, tempAmplitude, 2 * startAmplitude, 0);
path.rQuadTo(startAmplitude, -tempAmplitude, 2 * startAmplitude, 0);
}
} else {
//是单击
//根据当前次数调整振幅大小，有逐渐减小的趋势
float tempAmplitude = (1 - (float) currentCount / Count) * startAmplitude;
//因为想要形成波浪上下起伏的效果，所以根据currentCount的奇偶性来变化贝塞尔曲线转折点位置
if (currentCount % 2 == 0) {
for (int i = 0; i < cycleCount; i++) {
path.rQuadTo(startAmplitude, tempAmplitude, 2 * startAmplitude, 0);
path.rQuadTo(startAmplitude, -tempAmplitude, 2 * startAmplitude, 0);
}
} else {
for (int i = 0; i < cycleCount; i++) {
path.rQuadTo(startAmplitude, -tempAmplitude, 2 * startAmplitude, 0);
path.rQuadTo(startAmplitude, tempAmplitude, 2 * startAmplitude, 0);
}
}
}
path.close();
bitmapCanvas.drawPath(path, progressPaint);
String text = (int) (((float) currentProgress / maxProgress) * 100) + "%";
float textWidth = textPaint.measureText(text);
Paint.FontMetrics metrics = textPaint.getFontMetrics();
float baseLine = height / 2 - (metrics.ascent + metrics.descent);
bitmapCanvas.drawText(text, width / 2 - textWidth / 2, baseLine, textPaint);
canvas.drawBitmap(bitmap, 0, 0, null);
}
因为要呈现ProgressBall时不仅仅是其本身，或者还需要背景色或者文本之类的内容，所以可以将其置于ViewGroup中来显示
布局文件
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:id="@+id/layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:background="#556f7f8f"
android:clickable="true"
android:gravity="center"
android:orientation="vertical">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginTop="10dp"
android:gravity="center"
android:text="叶应是叶\nhttp://blog.csdn.net/new_one_object" />
<com.czy.floatball.View.ProgressBall
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="20dp" />
</LinearLayout>
</RelativeLayout>
FloatMenu就作为容纳ProgressBall的容器，并为其赋予从下往上滑动显示的动画效果
/**
* Created by ZY on 2016/8/10.
* 底部菜单栏
*/
public class FloatMenu extends LinearLayout {
private LinearLayout layout;
private TranslateAnimation animation;
public FloatMenu(final Context context) {
super(context);
View root = View.inflate(context, R.layout.float_menu, null);
layout = (LinearLayout) root.findViewById(R.id.layout);
animation = new TranslateAnimation(Animation.RELATIVE_TO_SELF, 0,
Animation.RELATIVE_TO_SELF, 0,
Animation.RELATIVE_TO_SELF, 1.0f,
Animation.RELATIVE_TO_SELF, 0);
animation.setDuration(500);
animation.setFillAfter(true);
layout.setAnimation(animation);
root.setOnTouchListener(new OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
ViewManager manager = ViewManager.getInstance(context);
manager.showFloatBall();
manager.hideFloatMenu();
return false;
}
});
addView(root);
}
public void startAnimation() {
animation.start();
}
}
这里提供源代码下载：https://github.com/leavesC/FloatBall
