Android 自定义消息右上角的数字提示或红点（类似微信或QQ的未读消息提示）
Android 一个可以自由定制外观、支持拖拽消除的MaterialDesign风格Android BadgeView
完成消息右上角的数字提示或红点，下面上图：
1.类似微信或QQ的未读消息提示，下面看看如何实现：
布局文件：
来看看主要的部分控件：
上面可以看出控件的结构，只要是我们自定义了一个DragPointView类：
import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.AnimatorSet;
import android.animation.ValueAnimator;
import android.animation.ValueAnimator.AnimatorUpdateListener;
import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.drawable.GradientDrawable;
import android.graphics.drawable.StateListDrawable;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.util.Log;
import android.view.Gravity;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewTreeObserver.OnPreDrawListener;
import android.view.animation.LinearInterpolator;
import android.view.animation.OvershootInterpolator;
import android.widget.AbsListView;
import android.widget.ScrollView;
import android.widget.TextView;
public class DragPointView extends TextView {
private boolean initBgFlag;
private OnDragListencer dragListencer;
private int backgroundColor = Color.parseColor("#f43530");
private PointView pointView;
private int x, y, r;
private ViewGroup scrollParent;
private int[] p = new int[2];
public DragPointView(Context context, AttributeSet attrs) {
super(context, attrs);
initbg();
}
public OnDragListencer getDragListencer() {
return dragListencer;
}
public void setDragListencer(OnDragListencer dragListencer) {
this.dragListencer = dragListencer;
}
public int getBackgroundColor() {
return backgroundColor;
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int w = getMeasuredWidth();
int h = getMeasuredHeight();
if (w != h) { // 简单的将宽高搞成一样的,如果有更好的方法欢迎在我博客下方留言!
int x = Math.max(w, h);
setMeasuredDimension(x, x);
}
}
@SuppressWarnings("deprecation")
public void setBackgroundColor(int backgroundColor) {
this.backgroundColor = backgroundColor;
DragPointView.this.setBackgroundDrawable(createStateListDrawable((getHeight() > getWidth() ? getHeight()
: getWidth()) / 2, backgroundColor));
}
private void initbg() {
setGravity(Gravity.CENTER);
getViewTreeObserver().addOnPreDrawListener(new OnPreDrawListener() {
@SuppressWarnings("deprecation")
@Override
public boolean onPreDraw() {
if (!initBgFlag) {
DragPointView.this.setBackgroundDrawable(createStateListDrawable(
(getHeight() > getWidth() ? getHeight() : getWidth()) / 2, backgroundColor));
initBgFlag = true;
return false;
}
return true;
}
});
}
@SuppressLint("ClickableViewAccessibility")
@Override
public boolean onTouchEvent(MotionEvent event) {
View root = getRootView();
if (root == null || !(root instanceof ViewGroup)) {
return false;
}
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
root.getLocationOnScreen(p);
scrollParent = getScrollParent();
if (scrollParent != null) {
scrollParent.requestDisallowInterceptTouchEvent(true);
}
int location[] = new int[2];
getLocationOnScreen(location);
x = location[0] + (getWidth() / 2) - p[0];
y = location[1] + (getHeight() / 2) - p[1];
r = (getWidth() + getHeight()) / 4;
pointView = new PointView(getContext());
pointView.setLayoutParams(new ViewGroup.LayoutParams(root.getWidth(), root.getHeight()));
setDrawingCacheEnabled(true);
pointView.catchBitmap = getDrawingCache();
pointView.setLocation(x, y, r, event.getRawX() - p[0], event.getRawY() - p[1]);
((ViewGroup) root).addView(pointView);
setVisibility(View.INVISIBLE);
break;
case MotionEvent.ACTION_MOVE:
pointView.refrashXY(event.getRawX() - p[0], event.getRawY() - p[1]);
break;
case MotionEvent.ACTION_CANCEL:
case MotionEvent.ACTION_UP:
if (scrollParent != null) {
scrollParent.requestDisallowInterceptTouchEvent(false);
}
if (!pointView.broken) { // 没有拉断
pointView.cancel();
} else if (pointView.nearby) {// 拉断了,但是又回去了
pointView.cancel();
} else { // 彻底拉断了
pointView.broken();
}
break;
default:
break;
}
return true;
}
private ViewGroup getScrollParent() {
View p = this;
while (true) {
View v;
try {
v = (View) p.getParent();
} catch (ClassCastException e) {
return null;
}
if (v == null)
return null;
if (v instanceof AbsListView || v instanceof ScrollView || v instanceof ViewPager) {
return (ViewGroup) v;
}
p = v;
}
}
public interface OnDragListencer {
void onDragOut();
}
class PointView extends View {
private Bitmap catchBitmap;
private Circle c1;
private Circle c2;
private Paint paint;
private Path path = new Path();
private int maxDistance = 8; // 10倍半径距离视为拉断
private boolean broken; // 是否拉断过
private boolean out; // 放手的时候是否拉断
private boolean nearby;
private int brokenProgress;
public PointView(Context context) {
super(context);
init();
}
public void init() {
paint = new Paint();
paint.setColor(backgroundColor);
paint.setAntiAlias(true);
}
public void setLocation(float c1X, float c1Y, float r, float endX, float endY) {
broken = false;
c1 = new Circle(c1X, c1Y, r);
c2 = new Circle(endX, endY, r);
}
public void refrashXY(float x, float y) {
c2.x = x;
c2.y = y;
// 以前的半径应该根据距离缩小点了
// 计算出距离
double distance = c1.getDistance(c2);
int rate = 10;
c1.r = (float) ((c2.r * c2.r * rate) / (distance + (c2.r * rate)));
Log.i("info", "c1: " + c1.r);
invalidate();
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawColor(Color.TRANSPARENT);
if (out) {
float dr = c2.r / 2 + c2.r * 4 * (brokenProgress / 100f);
Log.i("info", "dr" + dr);
canvas.drawCircle(c2.x, c2.y, c2.r / (brokenProgress + 1), paint);
canvas.drawCircle(c2.x - dr, c2.y - dr, c2.r / (brokenProgress + 2), paint);
canvas.drawCircle(c2.x + dr, c2.y - dr, c2.r / (brokenProgress + 2), paint);
canvas.drawCircle(c2.x - dr, c2.y + dr, c2.r / (brokenProgress + 2), paint);
canvas.drawCircle(c2.x + dr, c2.y + dr, c2.r / (brokenProgress + 2), paint);
} else {
// 绘制手指跟踪的圆形
if (catchBitmap == null || (catchBitmap != null && catchBitmap.isRecycled())) {
return;
}
canvas.drawBitmap(catchBitmap, c2.x - c2.r, c2.y - c2.r, paint);
path.reset();
float deltaX = c2.x - c1.x;
float deltaY = -(c2.y - c1.y);
double distance = Math.sqrt(deltaX * deltaX + deltaY * deltaY);
double sin = deltaY / distance;
double cos = deltaX / distance;
nearby = distance < c2.r * maxDistance;
if (nearby && !broken) {
canvas.drawCircle(c1.x, c1.y, c1.r, paint);
path.moveTo((float) (c1.x - c1.r * sin), (float) (c1.y - c1.r * cos));
path.lineTo((float) (c1.x + c1.r * sin), (float) (c1.y + c1.r * cos));
path.quadTo((c1.x + c2.x) / 2, (c1.y + c2.y) / 2, (float) (c2.x + c2.r * sin), (float) (c2.y + c2.r
* cos));
path.lineTo((float) (c2.x - c2.r * sin), (float) (c2.y - c2.r * cos));
path.quadTo((c1.x + c2.x) / 2, (c1.y + c2.y) / 2, (float) (c1.x - c1.r * sin), (float) (c1.y - c1.r
* cos));
canvas.drawPath(path, paint);
} else {
broken = true; // 已经拉断了
}
}
}
public void cancel() {
int duration = 150;
AnimatorSet set = new AnimatorSet();
ValueAnimator animx = ValueAnimator.ofFloat(c2.x, c1.x);
animx.setDuration(duration);
animx.setInterpolator(new OvershootInterpolator(2));
animx.addUpdateListener(new AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
c2.x = (float) animation.getAnimatedValue();
invalidate();
}
});
ValueAnimator animy = ValueAnimator.ofFloat(c2.y, c1.y);
animy.setDuration(duration);
animy.setInterpolator(new OvershootInterpolator(2));
animy.addUpdateListener(new AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
c2.y = (float) animation.getAnimatedValue();
invalidate();
}
});
set.playTogether(animx, animy);
set.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
ViewGroup vg = (ViewGroup) PointView.this.getParent();
vg.removeView(PointView.this);
DragPointView.this.setVisibility(View.VISIBLE);
}
});
set.start();
}
public void broken() {
out = true;
int duration = 500;
ValueAnimator a = ValueAnimator.ofInt(0, 100);
a.setDuration(duration);
a.setInterpolator(new LinearInterpolator());
a.addUpdateListener(new AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
brokenProgress = (int) animation.getAnimatedValue();
invalidate();
}
});
a.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
ViewGroup vg = (ViewGroup) PointView.this.getParent();
vg.removeView(PointView.this);
}
});
a.start();
if (dragListencer != null) {
dragListencer.onDragOut();
}
}
class Circle {
float x;
float y;
float r;
public Circle(float x, float y, float r) {
this.x = x;
this.y = y;
this.r = r;
}
public double getDistance(Circle c) {
float deltaX = x - c.x;
float deltaY = y - c.y;
double distance = Math.sqrt(deltaX * deltaX + deltaY * deltaY);
return distance;
}
}
}
/**
* @param radius 圆角角度
* @param color 填充颜色
* @return StateListDrawable 对象
* @author zy
*/
public static StateListDrawable createStateListDrawable(int radius, int color) {
StateListDrawable bg = new StateListDrawable();
GradientDrawable gradientStateNormal = new GradientDrawable();
gradientStateNormal.setColor(color);
gradientStateNormal.setShape(GradientDrawable.RECTANGLE);
gradientStateNormal.setCornerRadius(50);
gradientStateNormal.setStroke(0, 0);
bg.addState(View.EMPTY_STATE_SET, gradientStateNormal);
return bg;
}
}2.代码中实现：
DragPointView mUnreadNumView = (DragPointView) findViewById(R.id.seal_num);
mUnreadNumView.setOnClickListener(this);
mUnreadNumView.setDragListencer(this); if (count == 0) {
mUnreadNumView.setVisibility(View.GONE);
} else if (count > 0 && count < 100) {
mUnreadNumView.setVisibility(View.VISIBLE);
mUnreadNumView.setText(String.valueOf(count));
} else {
mUnreadNumView.setVisibility(View.VISIBLE);
mUnreadNumView.setText(R.string.no_read_message);
}进而设置显示样式和是否显示，通常上面是和融云结合使用的
相似案例：
https://github.com/qstumn/BadgeView
https://github.com/Dalanger/MyBaseProject
https://github.com/MonkeyMushroom/DragBubbleView
https://github.com/younfor/BubbleDrag
https://github.com/chenchengyin/QQPresentation
https://github.com/A-Miracle/Bubble-Drag
https://github.com/AlexLiuSheng/BadgeView
https://github.com/stefanjauker/BadgeView