送给有需要的人 - Githubissues

salmanit commented 6 years ago

本来想看源码学习的，看着好多代码，累了，就想着自己弄，看了看效果，感觉就是线性的，唯一的区别就是第一个item有个变化而已。代码如下，继承LinearLayoutManager重写如下的方法即可，基本可以达到效果，好像有人想要横向的，逻辑也差不多。

` var oldChild0:View?=null; override fun scrollVerticallyBy(dy: Int, recycler: RecyclerView.Recycler, state: RecyclerView.State?): Int { val result=super.scrollVerticallyBy(dy, recycler, state) if(childCount>1){ val child1=getChildAt(1) val child0=getChildAt(0) if(oldChild0!=null&&oldChild0!=child0){ resetChild(oldChild0!!) } oldChild0=child0 var scale=0.7f+0.3f*(child1.top)/getDecoratedMeasuredHeight(child1)

        child0.pivotX=child0.width/2f
        child0.pivotY=child0.height/1f
        child0.scaleX=scale
        child0.scaleY=scale
        child0.translationY=getDecoratedMeasuredHeight(child1)-child1.top.toFloat()
        child0.alpha=scale
        if(scale<0.7){
            resetChild(child0)
            removeAndRecycleView(child0,recycler)
        }
    }
    return  result
}
private fun resetChild(child:View){
    child.apply {
        pivotY=this.width/2f
        pivotX=this.height/1f
        scaleX=1f;
        scaleY=1f;
        alpha=1f;
        translationY=0f
    }
}

`

thundeGG commented 6 years ago

大佬，有demo吗

salmanit commented 6 years ago

@7hundeR 上边代码也差不多了，你继承LinearLayoutManager 就完事了。也没啥demo吧，recyclerView该咋用咋用，就是layoutManager用这个就行了。 `import android.content.Context import android.support.v7.widget.LinearLayoutManager import android.support.v7.widget.RecyclerView import android.view.View

class LayoutManagerScaleFirst:LinearLayoutManager{ constructor(context: Context?) : super(context) constructor(context: Context?, orientation: Int, reverseLayout: Boolean) : super(context, orientation, reverseLayout)

private var oldChild0:View?=null;
private val scaleMinFactor=0.7f //from 0 to 1
override fun scrollVerticallyBy(dy: Int, recycler: RecyclerView.Recycler, state: RecyclerView.State?): Int {
    val result=super.scrollVerticallyBy(dy, recycler, state)
    if(childCount>1){
        val child1=getChildAt(1)
        val child0=getChildAt(0)
        if(oldChild0!=null&&oldChild0!=child0){
            resetChild(oldChild0!!)
        }
        oldChild0=child0
        val scale=scaleMinFactor+(1-scaleMinFactor)*(child1.top)/getDecoratedMeasuredHeight(child1)
        println("scrollVerticallyBy====${scale}==childCount=${childCount}===${getChildAt(0).height}====${getChildAt(1).top}")
        viewAnimate(child0,scale,getDecoratedMeasuredHeight(child1)-child1.top.toFloat())
        if(scale<scaleMinFactor){
            resetChild(child0)
            removeAndRecycleView(child0,recycler)
        }
    }
    return  result
}
private fun resetChild(child:View){
    viewAnimate(child,1f,0f)
}

private fun viewAnimate(child: View,factor:Float,transY:Float){
    child.apply {
        pivotX=this.width/2f
        pivotY=this.height/1f
        scaleX=factor;
        scaleY=factor;
        alpha=factor;
        translationY=transY
    }
}

}`

thundeGG commented 5 years ago

感谢大佬

thundeGG commented 5 years ago

加上margin或者padding后能看到顶上缩小的view

salmanit commented 5 years ago

不知道你说的啥样子，上下margin用decoration就行，左右的margin应该没啥影响吧，我这里是滑动的效果图，没看出有啥问题。或者你具体说下，给谁添加margin？另外我就是个菜鸟。 https://www.jianshu.com/p/42f9997e3ce0

xmuSistone / VegaLayoutManager

送给有需要的人 #36