简单弹幕库，先看一下效果:
该库主要是控制消息队列，当将消息添加进队列后，何时触发弹幕，如果来一个消息就触发一条弹幕可能会出现弹幕重叠，不合产品需要，例如只有当前一个弹幕的尾部完全进入屏幕后才能进行下一个弹幕，再例如直播间送特效礼物的时候，不能来一个特效礼物就播放一个，而是要保证前一个播放完成，才能进行下一个。等等诸如此类的场景很多。
使用方法:
//先在gradle中添加依赖
compile 'com.github.airland:simpledanmu:1.0.7'
接着布局文件中：
<com.airland.simpledanmuku.widget.SimpleDanmuView
android:id="@+id/id_sd"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
app:rowCount="1"
app:isEnableOverLayer="false"
app:oneByOneEnter="true"
/>
在Activity中,和使用ListView类似，首先findview然后给view设置adapter，这里的adapter要传入泛型，也就是弹幕上数据的bean对象，这个bean要继承AbstractMessage例如下面例子中的TestMessage，getView返回的则是对应的弹幕view：
SimpleDanmuView simpleDanmuView = findViewById(R.id.id_sd);
simpleDanmuView.setMessageAdapter(new ISimpleMessageAdapter<AbstractMessage>() {
@Override
public SimpleItemBaseView getView(AbstractMessage testMessage) {
if (testMessage.getMsgType()==1){
SimpleItemPictureView simpleItemPictureView = new SimpleItemPictureView(MainActivity.this);
simpleItemPictureView.getContentView().setText(((TestMessage)testMessage.getBean()).getContent());
return simpleItemPictureView;
}else{
SimpleItemTextView simpleItemTextView = new SimpleItemTextView(MainActivity.this);
simpleItemTextView.getTextView().setText(((TestMessage)testMessage.getBean()).getContent());
return simpleItemTextView;
}
}
});
//在destory的时候调用endDealWithMessage释放资源
@Override
protected void onDestroy() {
super.onDestroy();
simpleDanmuView.endDealWithMessage();
}
在需要发送弹幕的地方调用：
simpleDanmuView.addInMessageQueue(testMessage);
自定义效果分为：自定义ItemView和ContainerView,如果你需要的是上面的弹幕滚动效果，只需要定义自己的ItemView即可，ContainerView可以使用SimpleDanmuView，如果你需要定义自己的滚动方式可以自定义ContainerView。
ContainerView需要继承SimpleBaseDanmuView，重写startItemDanmuView方法，ItemView需要继承SimpleItemBaseView，从而实现自己需要的动画效果，例如上方Gif图中，实现花椒直播欢迎条效果：
以下是一个例子
//自定义ContainerView
public class SimpleWelcomeView extends SimpleBaseDanmuView {
private Handler mHandler;
public SimpleWelcomeView(@NonNull Context context) {
this(context, null);
}
public SimpleWelcomeView(@NonNull Context context, @Nullable AttributeSet attrs) {
this(context, attrs, 0);
}
public SimpleWelcomeView(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
initData();
}
private void initData() {
everyRowHeight = 30;
mHandler = new Handler(Looper.getMainLooper());
}
@Override
public void startItemDanmuView(final SimpleItemBaseView simpleItemBaseView) {
super.startItemDanmuView(simpleItemBaseView);
if (simpleItemBaseView != null && currentState == RUNNING) {
int row = simpleItemBaseView.getRowNumber();
if (row <= rowCount) {
FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, dp2px(everyRowHeight));
addView(simpleItemBaseView, layoutParams);
simpleItemBaseView.setTranslationX(getMeasuredWidth());
startScrollView(simpleItemBaseView);
}
}
}
@Override
public int getState() {
return currentState;
}
private void startScrollView(final SimpleItemBaseView simpleItemBaseView) {
if (mHandler != null) {
mHandler.post(new Runnable() {
@Override
public void run() {
startAnimation(simpleItemBaseView);
}
});
}
}
private void startAnimation(final SimpleItemBaseView simpleItemBaseView) {
int width = simpleItemBaseView.getWidth();
int startMargin = getMeasuredWidth();
int endMargin = -width;
FrameLayout.LayoutParams layoutParams = (FrameLayout.LayoutParams) simpleItemBaseView.getLayoutParams();
layoutParams.width = width;
simpleItemBaseView.setLayoutParams(layoutParams);
AnimatorSet animatorSet = new AnimatorSet();
ValueAnimator valueAnimator_one = ValueAnimator.ofInt(startMargin, 50);
ValueAnimator valueAnimator_two = ValueAnimator.ofInt(50, 10);
ValueAnimator valueAnimator_three = ValueAnimator.ofInt(10, endMargin);
valueAnimator_one.setDuration(300);
valueAnimator_two.setDuration(3000);
valueAnimator_three.setDuration(300);
valueAnimator_one.setInterpolator(new AccelerateInterpolator());
valueAnimator_two.setInterpolator(new LinearInterpolator());
valueAnimator_three.setInterpolator(new AccelerateInterpolator());
valueAnimator_one.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
updateLeft(simpleItemBaseView, animation, false);
}
});
valueAnimator_two.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
SimpleItemWelcomeView simpleItemWelcomeView = (SimpleItemWelcomeView) simpleItemBaseView;
simpleItemWelcomeView.startAnimation();
updateLeft(simpleItemBaseView, animation, false);
}
});
valueAnimator_three.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
updateLeft(simpleItemBaseView, animation, true);
}
});
animatorSet.playSequentially(valueAnimator_one, valueAnimator_two, valueAnimator_three);
animatorSet.start();
}
private void updateLeft(SimpleItemBaseView simpleItemBaseView, ValueAnimator animation, boolean isRemove) {
if (currentState == RUNNING) {
int value = (int) animation.getAnimatedValue();
simpleItemBaseView.setTranslationX(value);
if (isRemove && animation.getAnimatedFraction() == 1) {
removeView(simpleItemBaseView);
endItemDanmuView(simpleItemBaseView);
}
} else {
if (animation.isRunning())
animation.cancel();
}
}
public void stop() {
currentState = STOP;
if (mHandler != null)
mHandler.removeCallbacksAndMessages(null);
mHandler = null;
removeAllViews();
}
public void resume() {
currentState = RUNNING;
mHandler = new Handler(Looper.getMainLooper());
}
}
//自定义ItemView（花椒的子View也有动画实现：左上角高光闪动的星星，还有扫过整个欢迎条的高光条）：
public class SimpleItemWelcomeView extends SimpleItemBaseView {
private ImageView headPictureView;
private TextView contentView;
private TextView nameView;
private ImageView backgroundView;
private ImageView lightStarView;
private ImageView lightLineView;
private ImageView levelView;
private boolean isStart;
public SimpleItemWelcomeView(Context context) {
super(context);
init(context);
}
private void init(Context context) {
View rootView = LayoutInflater.from(context).inflate(R.layout.simple_welcome_layout, this, true);
backgroundView = rootView.findViewById(R.id.id_img_welcome_bg);
headPictureView = rootView.findViewById(R.id.id_civ_welcome_headpic);
lightStarView = rootView.findViewById(R.id.id_iv_welcome_light);
lightLineView = rootView.findViewById(R.id.id_iv_welcome_line);
levelView = rootView.findViewById(R.id.id_img_welcome_user_level);
nameView = rootView.findViewById(R.id.id_tv_welcome_name);
contentView = rootView.findViewById(R.id.id_tv_welcome_content);
}
public ImageView getHeadPictureView() {
return headPictureView;
}
public TextView getNameView() {
return nameView;
}
public TextView getContentView() {
return contentView;
}
public ImageView getBackgroundView() {
return backgroundView;
}
public ImageView getLevelView() {
return levelView;
}
public ImageView getLightStarView() {
return lightStarView;
}
public void startAnimation() {
if (!isStart){
isStart = true;
ObjectAnimator alpha_objectAnimator = ObjectAnimator.ofFloat(lightStarView, "alpha", 0.2f, 1.0f);
alpha_objectAnimator.setRepeatCount(4);
ObjectAnimator scaleX_objectAnimator = ObjectAnimator.ofFloat(lightStarView, "scaleX", 0.2f, 1.2f);
scaleX_objectAnimator.setRepeatCount(4);
ObjectAnimator scaleY_objectAnimator = ObjectAnimator.ofFloat(lightStarView, "scaleY", 0.2f, 1.2f);
scaleY_objectAnimator.setRepeatCount(4);
AnimatorSet animatorSet = new AnimatorSet();
animatorSet.setDuration(600);
animatorSet.playTogether(alpha_objectAnimator, scaleX_objectAnimator, scaleY_objectAnimator);
animatorSet.start();
lightStarView.setVisibility(VISIBLE);
ObjectAnimator translationX_objectAnimator = ObjectAnimator.ofFloat(lightLineView, "translationX", 0, 0.832f * getWidth() - lightLineView.getX());
translationX_objectAnimator.addListener(new Animator.AnimatorListener() {
@Override
public void onAnimationStart(Animator animation) {
}
@Override
public void onAnimationEnd(Animator animation) {
lightLineView.setVisibility(INVISIBLE);
}
@Override
public void onAnimationCancel(Animator animation) {
}
@Override
public void onAnimationRepeat(Animator animation) {
}
});
translationX_objectAnimator.setRepeatCount(1);
translationX_objectAnimator.setDuration(1200);
translationX_objectAnimator.start();
lightLineView.setVisibility(VISIBLE);
}
}
}
然后在Activity中和上面使用方法类似：
SimpleWelcomeView simpleWelcomeView = findViewById(R.id.id_sw);
simpleWelcomeView.setMessageAdapter(new ISimpleMessageAdapter<TestMessage>() {
@Override
public int getRowCount() {
return 1;
}
@Override
public SimpleItemBaseView getView(TestMessage testMessage) {
SimpleItemWelcomeView simpleItemWelcomeView = new SimpleItemWelcomeView(MainActivity.this);
simpleItemWelcomeView.getNameView().setText(testMessage.getContent());
return simpleItemWelcomeView;
}
});
继承SimpleBaseDanmuView的弹幕容器view除了重写startItemDanmuView（）开始动画，还需要在动画结束时候调用endItemDanmuView（）。弹幕显示下一条的时机问题，例如，只有当前一个弹幕完全进入屏幕，后一个弹幕才能进来，再或者说只有当前一个欢迎条完全离开屏幕后，下一个才能进来。这个时机是由使用者定，只需在可以显示下一个弹幕的时候调用setNextIndicator(simpleItemBaseView.rowNumber, true);在不调用的情况下默认是一条弹幕结束后下一个才会开始。