直接上动图：
ILayoutAnimationController录屏.gif
源码及DEMO已上传至GitHub:ILayoutAnimationController,欢迎大家提Bug,喜欢的话记得Star或Fork下哈!
1：ILayoutAnimationController是什么？其实现思路是？
- LayoutAnimationController大家应该都了解，应用于ViewGroup实例的布局动画，但Android原生布局动画，仅支持顺序、倒序、随机3种动画执行顺序！
- ILayoutAnimationController是一个自定义LayoutAnimationController，通过重写其getTransformedIndex方法，1行代码即可任意定制布局动画的执行顺序，实现不同展示效果！
2：使用方法：
方法一：1行代码直接搞定,以下两种方法任选其一
ILayoutAnimationController.setLayoutAnimation(@NonNull ViewGroup viewGroup, @NonNull Animation animation, float delay, @Nullable final IndexAlgorithm indexAlgorithm)
ILayoutAnimationController.setLayoutAnimation(@NonNull ViewGroup viewGroup,@AnimRes int animResId, float delay,@Nullable final IndexAlgorithm indexAlgorithm)
方法二：首先创建ILayoutAnimationController实例，然后将此实例作为参数为ViewGroup设置布局动画
ILayoutAnimationController.generateController(@NonNull Animation animation, float delay, @Nullable final IndexAlgorithm indexAlgorithm)
ViewGroup.setLayoutAnimation(LayoutAnimationController controller)
3：示例代码：
LinearLayout ll = (LinearLayout) findViewById(R.id.ll);
//两行代码设置布局动画：
ILayoutAnimationController controller =
ILayoutAnimationController.generateController(
AnimationUtils.loadAnimation(this,R.anim.activity_open_enter),
0.8f,
ILayoutAnimationController.IndexAlgorithm.INDEXSIMPLEPENDULUM);
ll.setLayoutAnimation(controller);
//一行代码直接搞定：
ILayoutAnimationController.setLayoutAnimation(
ll,
R.anim.activity_open_enter,
0.8f,
ILayoutAnimationController.IndexAlgorithm.INDEXSIMPLEPENDULUM);
4：ILayoutAnimationController部分代码：
public class ILayoutAnimationController extends LayoutAnimationController {
private Callback onIndexListener;
public void setOnIndexListener(Callback onIndexListener) {
this.onIndexListener = onIndexListener;
}
public ILayoutAnimationController(Context context, AttributeSet attrs) {
super(context, attrs);
}
public ILayoutAnimationController(Animation animation) {
super(animation);
}
public ILayoutAnimationController(Animation animation, float delay) {
super(animation, delay);
}
@Override
protected int getTransformedIndex(AnimationParameters params) {
if (onIndexListener!=null){
return onIndexListener.getTransformedIndex(
this,
params.count,
params.index);
}else{
return super.getTransformedIndex(params);
}
}
/**
* callback for get play animation order
*/
public interface Callback{
public int getTransformedIndex(
ILayoutAnimationController controller,
int count,
int index);
}
/**
* 根据当前枚举类型的值，确定在setOnIndexListener方法中的
* CustomLayoutAnimationController.Callback
* 实例的getTransformedIndex方法调用GetTransformedIndexUtils中的那种方法
*/
public enum IndexAlgorithm{
INDEX1325476,
INDEX135246,
INDEX246135,
INDEXSIMPLEPENDULUM,
MIDDLETOEDGE,
INDEX15263748,
INDEX1325476REVERSE,
INDEX135246REVERSE,
INDEX246135REVERSE,
INDEXSIMPLEPENDULUMREVERSE,
INDEXMIDDLETOEDGEREVERSE,
INDEX15263748REVERSE
}
public static ILayoutAnimationController generateController(
Animation animation, float delay){
return generateController(animation,delay,null);
}
/**
* 根据指定的动画、单个子View动画延时、
* 子View动画执行顺序算法枚举值，
* 创建一个新的CustomLayoutAnimationController实例
* @param animation the animation to use on each child of the view group
* @param delay the delay by which each child's animation must be offset
* @param indexAlgorithm 子View动画执行顺序算法枚举值
* @return
*/
public static ILayoutAnimationController generateController(
@NonNull Animation animation,
float delay,
@Nullable final IndexAlgorithm indexAlgorithm){
ILayoutAnimationController controller =
new ILayoutAnimationController(animation,delay);
controller.setOnIndexListener(new Callback() {
@Override
public int getTransformedIndex(
ILayoutAnimationController controller, int count, int index) {
if(indexAlgorithm != null){
switch (indexAlgorithm){
case INDEX1325476:
return GetTransformedIndexUtils
.getTransformedIndex1325476(count,index);
case INDEX135246:
return GetTransformedIndexUtils
.getTransformedIndex135246(count,index);
case INDEX246135:
return GetTransformedIndexUtils
.getTransformedIndex246135(count,index);
case INDEXSIMPLEPENDULUM:
return GetTransformedIndexUtils
.getTransformedIndexSimplePendulum(
count,index);
case MIDDLETOEDGE:
return GetTransformedIndexUtils
.getTransformedIndexMiddleToEdge(
count,index);
case INDEX15263748:
return GetTransformedIndexUtils
.getTransformedIndex15263748(count,index);
case INDEX1325476REVERSE:
return GetTransformedIndexUtils
.getTransformedIndex1325476REVERSE(
count,index);
case INDEX135246REVERSE:
return GetTransformedIndexUtils
.getTransformedIndex135246REVERSE(
count,index);
case INDEX246135REVERSE:
return GetTransformedIndexUtils
.getTransformedIndex246135REVERSE(
count,index);
case INDEXSIMPLEPENDULUMREVERSE:
return GetTransformedIndexUtils
.getTransformedIndexSimplePendulumREVERSE(
count,index);
case INDEXMIDDLETOEDGEREVERSE:
return GetTransformedIndexUtils
.getTransformedIndexMiddleToEdgeREVERSE(
count,index);
case INDEX15263748REVERSE:
return GetTransformedIndexUtils
.getTransformedIndex15263748REVERSE(
count,index);
default:
break;
}
}
return index;
}
});
return controller;
}
/**
* 根据指定的动画、单个子View动画延时、
* 子View动画执行顺序算法枚举值，
* 创建一个新的CustomLayoutAnimationController实例，
* 将此实例作为参数为viewGroup设置布局动画
* @param viewGroup
* @param animation
* @param delay
* @param indexAlgorithm
*/
public static void setLayoutAnimation(
@NonNull ViewGroup viewGroup,
@NonNull Animation animation,
float delay,
@Nullable final IndexAlgorithm indexAlgorithm){
ILayoutAnimationController controller =
generateController(animation,delay,indexAlgorithm);
viewGroup.setLayoutAnimation(controller);
}
/**
* 根据传入的动画资源ID、单个子View动画延时、
* 子View动画执行顺序算法枚举值，
* 创建一个新的CustomLayoutAnimationController实例，
* 将此实例作为参数为viewGroup设置布局动画
* @param viewGroup
* @param animResId
* @param delay
* @param indexAlgorithm
*/
public static void setLayoutAnimation(
@NonNull ViewGroup viewGroup,
@AnimRes int animResId,
float delay,
@Nullable final IndexAlgorithm indexAlgorithm){
Animation animation = AnimationUtils.loadAnimation(
viewGroup.getContext(),animResId);
setLayoutAnimation(viewGroup,animation,delay,indexAlgorithm);
}
}
public final class GetTransformedIndexUtils {
**略**
/**
* 先执行第1项 的布局动画,
* 然后执行第3项 的布局动画,然后执行第2项 的布局动画,
* 然后执行第5项 的布局动画,然后执行第4项 的布局动画,
* 然后执行第7项 的布局动画,然后执行第6项 的布局动画---
* @param count
* @param index
* @return
*/
public static int getTransformedIndex1325476(int count, int index){
if ((index + 1) % 2 != 0) {
if (index == 0) {
return index;
} else {
return index - 1;
}
} else {
if (index == count - 1) {
return index;
} else {
return index + 1;
}
}
}
/**
* 先执行奇数项 的布局动画,再执行偶数项 的布局动画
* @param count
* @param index
* @return
*/
public static int getTransformedIndex135246(int count, int index){
if (index%2==0){
//1:奇数项
return index/2;
}else {
//2:偶数项
if(count%2==0){
//2.1:当总项数是偶数
return (count/2-1) + (index+1)/2;
}else {
//2.2:当总项数是奇数
return (count/2) + (index+1)/2;
}
}
}
**略**
}
注意：
- 使用ILayoutAnimationController获取的ILayoutAnimationController实例，调用setOrder(int order)方法无效！
LayoutAnimation基础知识：
就不再详述，不太了解的同学可以看看这篇博客,CSDN上随意搜就好多：
Android 动画之LayoutAnimation
源码及DEMO已上传至GitHub:ILayoutAnimationController,欢迎大家提Bug,喜欢的话记得Star或Fork下哈!
That's all !
