package cn.tangdada.tangbang.widget; import android.annotation.TargetApi; import android.content.Context; import android.content.res.TypedArray; import android.graphics.drawable.BitmapDrawable; import android.os.Build; import android.util.AttributeSet; import android.view.MotionEvent; import android.view.View; import android.view.ViewConfiguration; import android.view.animation.AccelerateInterpolator; import android.widget.AbsListView; import android.widget.ListView; import cn.tangdada.tangbang.R; import com.nineoldandroids.view.ViewPropertyAnimator; /** * 当滑动到顶部和底部时,实现Item的分离效果。 * * @author pythoner * */ @TargetApi(Build.VERSION_CODES.HONEYCOMB) public class PullSeparateListView extends ListView { /** * 最大滑动距离 */ private static final float MAX_DELTAY = 100; /** * 分离后恢复的动画时长 */ private static final long SEPARATE_RECOVER_DURATION = 200; /** * 摩擦系数 */ private static final float FACTOR = 0.25f; /** * 按下x的缩放比例 */ private static final float SCALEX = 1.0f; /** * 按下y的缩放比例 */ private static final float SCALEY = 1.0f; /** * 展开全部 */ private boolean separateAll; /** * 到达边界时,滑动的起始位置 */ private float startY; /** * 按下时的View */ private View downView; private int touchSlop; private boolean separate = false; private boolean showDownAnim; /** * 原始按下位置(在所有Item中的位置) */ private int originDownPosition; /** * 按下的位置(在屏幕中的位置) */ private int downPosition; /** * 上次滑动的位置,用于判断方向 */ private float preY; private float deltaY; private boolean reachTop, reachBottom, move; private OnScrollListener mScrollListener; public PullSeparateListView(Context context, AttributeSet attrs) { super(context, attrs); TypedArray t = context.obtainStyledAttributes(attrs, R.styleable.PullSeparateListView); separateAll = t.getBoolean(R.styleable.PullSeparateListView_separate_all, false); showDownAnim = t.getBoolean(R.styleable.PullSeparateListView_showDownAnim, true); t.recycle(); init(); } public PullSeparateListView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); init(); } public PullSeparateListView(Context context) { super(context); init(); } @SuppressWarnings("deprecation") private void init() { // 不知道怎么让divider和selector和Item一起移动,所以去除,需要自己加分割线 this.setDivider(null); this.setSelector(new BitmapDrawable()); touchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop(); super.setOnScrollListener(listener); } /** * 是否全部分离 * * @param separateAll 如果为true,那么全部都会分离。否则的话,如果是顶部下拉,只有点击位置之前的Item会分离</br> 如果是底部上拉,则只有点击位置之后的item会分离。默认为false */ public void setSeparateAll(boolean separateAll) { this.separateAll = separateAll; } public boolean isSeparateAll() { return separateAll; } /** * 设置是否显示按下的Item的动画效果 * * @param showDownAnim 默认为true */ public void setShowDownAnim(boolean showDownAnim) { this.showDownAnim = showDownAnim; } public boolean isShowDownAnim() { return showDownAnim; } public void setOnScrollListener(OnScrollListener l) { mScrollListener = l; } // 核心代码 @Override public boolean dispatchTouchEvent(MotionEvent ev) { float currentY = ev.getY(); switch (ev.getAction()) { case MotionEvent.ACTION_DOWN: float downX = ev.getX(); float downY = ev.getY(); // 记录按下位置,当isSeparateAll()返回false时,会用到 originDownPosition = pointToPosition((int) downX, (int) downY); downPosition = originDownPosition - getFirstVisiblePosition(); if (showDownAnim) { performDownAnim(downPosition); } break; case MotionEvent.ACTION_MOVE: // 记录到达顶部或底部时手指的位置 if (!separate) { startY = currentY; } deltaY = currentY - startY; // 到达顶部 if (reachTop) { if (!separateFromTop(currentY)) { return super.dispatchTouchEvent(ev); } return false; } // 到达底部 if (reachBottom) { if (!separateFromBottom(currentY)) { return super.dispatchTouchEvent(ev); } return false; } preY = currentY; break; case MotionEvent.ACTION_CANCEL: case MotionEvent.ACTION_UP: preY = 0; recoverDownView(); if (separate) { separate = false; recoverSeparate(); // 移动,不响应点击事件 if (move) { move = false; return false; } } break; } return super.dispatchTouchEvent(ev); } private boolean separateFromTop(float currentY) { // 不能放在外部,否则在顶部滑动没有Fling效果 if (deltaY > touchSlop) { move = true; } separate = true; // 超过滑动允许的最大距离,则将起始位置向下移 if (deltaY > MAX_DELTAY) { startY = currentY - MAX_DELTAY; // 超过最大距离时,出现overScroll效果//有问题 // return super.dispatchTouchEvent(ev); } else if (deltaY < 0) { // 为负值时(说明反方向超过了起始位置startY)归0 deltaY = 0; separate = false; } if (deltaY <= MAX_DELTAY) { for (int index = 0; index < getChildCount(); index++) { View child = getChildAt(index); int multiple = index; if (!separateAll) { if (index > downPosition) { multiple = Math.max(1, downPosition); } } float distance = multiple * deltaY * FACTOR; child.setTranslationY(distance); } // 向分离方向的反方向滑动,但位置还未复原时 if (deltaY != 0 && currentY - preY < 0) { return true; } // deltaY=0,说明位置已经复原,然后交给父类处理 } if (deltaY == 0) { return false; } return true; } private boolean separateFromBottom(float currentY) { if (Math.abs(deltaY) > touchSlop) { move = true; } separate = true; // 超过滑动允许的最大距离,则将起始位置向上移 if (Math.abs(deltaY) > MAX_DELTAY) { startY = currentY + MAX_DELTAY; // 超过最大距离时,出现overScroll效果 // return super.dispatchTouchEvent(ev); } else if (deltaY > 0) { // 为正值时(说明反方向移动超过起始位置startY),归0 deltaY = 0; separate = false; } if (Math.abs(deltaY) <= MAX_DELTAY) { int visibleCount = getChildCount(); for (int inedex = 0; inedex < visibleCount; inedex++) { View child = getChildAt(inedex); int multiple = visibleCount - inedex - 1; if (!separateAll) { if (inedex < downPosition) { multiple = Math.max(1, visibleCount - downPosition - 1); } } float distance = multiple * deltaY * FACTOR; child.setTranslationY(distance); } // 向分离方向的反方向滑动,但位置还未复原时 if (deltaY != 0 && currentY - preY > 0) { return true; } // deltaY=0,说明位置已经复原,然后交给父类处理 if (deltaY == 0) { return false; } } return true; } /** * 恢复 */ private void recoverSeparate() { for (int i = 0; i < getChildCount(); i++) { View child = getChildAt(i); ViewPropertyAnimator.animate(child).translationY(0).setDuration(SEPARATE_RECOVER_DURATION).setInterpolator(new AccelerateInterpolator()); } } /** * 按下的动画 * * @param downPosition 在屏幕中的位置 */ private void performDownAnim(int downPosition) { downView = getChildAt(downPosition); if (downView != null) { ViewPropertyAnimator.animate(downView).scaleX(SCALEX).scaleY(SCALEY).setDuration(50).setInterpolator(new AccelerateInterpolator()); } } /** * 恢复点击的View */ private void recoverDownView() { if (showDownAnim && downView != null) { ViewPropertyAnimator.animate(downView).scaleX(1f).scaleY(1f).setDuration(separate ? SEPARATE_RECOVER_DURATION : 100) .setInterpolator(new AccelerateInterpolator()); } } private OnScrollListener listener = new OnScrollListener() { @Override public void onScrollStateChanged(AbsListView view, int scrollState) { if (mScrollListener != null) { mScrollListener.onScrollStateChanged(view, scrollState); } } @Override public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { if (mScrollListener != null) { mScrollListener.onScroll(view, firstVisibleItem, visibleItemCount, totalItemCount); } // 是否到达顶部 if (firstVisibleItem == 0) { View firstView = getChildAt(firstVisibleItem); if (firstView != null && (firstView.getTop() + getPaddingTop()) >= 0) { downPosition = originDownPosition; reachTop = true; } else { reachTop = false; } } else { reachTop = false; } // 是否到达底部 if (firstVisibleItem + visibleItemCount == getCount()) { View lastView = getChildAt(visibleItemCount - 1); if (lastView != null && (lastView.getBottom() + getPaddingBottom()) <= getHeight() && getCount() > getChildCount()) { downPosition = originDownPosition - firstVisibleItem; reachBottom = true; } else { reachBottom = false; } } else { reachBottom = false; } } }; /** * 是否到达顶部 * * @return */ @Deprecated protected boolean isReachTopBound() { int firstVisPos = getFirstVisiblePosition(); if (firstVisPos == 0) { View firstView = getChildAt(firstVisPos); if (firstView != null && firstView.getTop() >= 0) { return true; } else { return false; } } return false; } /** * 是否到达底部 * * @return */ @Deprecated protected boolean isReachBottomBound() { int lastVisPos = getLastVisiblePosition(); if (lastVisPos == getCount() - 1) { View lastView = getChildAt(getChildCount() - 1); if (lastView != null && lastView.getBottom() <= getHeight() && getCount() > getChildCount()) { return true; } else { return false; } } return false; } }
自定义属性:
<?xml version="1.0" encoding="utf-8"?> <resources> <declare-styleable name="PullSeparateListView"> <attr name="separate_all" format="boolean"/> <attr name="showDownAnim" format="boolean"/> </declare-styleable> </resources>
高仿墨迹天气下拉拉伸图片,释放后返回效果
http://blog.csdn.net/wu928320442/article/details/44198157
ListView 滚动到边缘时,item产生缩放效果
http://www.jcodecraeer.com/a/opensource/2015/1204/3748.html