Android 仿百度手机助手首页滑动效果 demo代码

package com.example.materialtest.widget; import android.animation.ObjectAnimator; import android.animation.ValueAnimator; import android.animation.ValueAnimator.AnimatorUpdateListener; import android.content.Context; import android.graphics.PointF; import android.graphics.RectF; import android.support.v4.view.ViewCompat; import android.util.AttributeSet; import android.util.Log; import android.view.MotionEvent; import android.view.View; import android.widget.AbsListView; import android.widget.AbsListView.OnScrollListener; import android.widget.LinearLayout; import com.example.materialtest.R; /** * 滑动隐藏控件 * * */ public class ScrollHideLayout extends LinearLayout implements OnScrollListener { private static final String TAG = ScrollHideLayout.class.getSimpleName(); private int scrollViewId = R.id.scrollView; private int changeViewId = R.id.changeView; private int changeViewMaxHeight; private PointF touchPoint = new PointF(); private View changeView; private AbsListView scrollView; private RectF scrollViewRect = new RectF(); public ScrollHideLayout(Context context, AttributeSet attrs) { this(context, attrs, 0); } public ScrollHideLayout(Context context) { this(context, null); } public ScrollHideLayout(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); int len = getChildCount(); if (null == changeView || null == scrollView) { for (int i = 0; i < len; i++) { View child = getChildAt(i); // 滑动控件 if (child.getId() == scrollViewId && child instanceof AbsListView) { scrollView = (AbsListView) child; setScrollViewRect(); } if (child.getId() == changeViewId) { changeView = child; changeView.setMinimumHeight(0); changeViewMaxHeight = changeView.getMeasuredHeight(); } } } else { // 重新计算滚动控件的位置 setScrollViewRect(); } Log.i(TAG, "find scrollview and changeView :" + scrollViewId + "," + changeViewId); Log.i(TAG, "scrollview rect:" + changeView.getLayoutParams().getClass().getCanonicalName()); if (null == changeView || null == scrollView) { throw new IllegalArgumentException("could not foud changeView or scrollView"); } } private void setScrollViewRect() { // 获取滚动控件的范围 float left = ViewCompat.getX(scrollView); float top = ViewCompat.getY(scrollView); float right = left + scrollView.getMeasuredWidth(); float bottom = top + scrollView.getMeasuredHeight(); scrollViewRect.left = left; scrollViewRect.top = top; scrollViewRect.right = right; scrollViewRect.bottom = bottom; } @Override public boolean onTouchEvent(MotionEvent ev) { if (!isScrollViewTouch(ev)) { return false; } final android.view.ViewGroup.LayoutParams params = changeView.getLayoutParams(); switch (ev.getAction()) { case MotionEvent.ACTION_DOWN: touchPoint.x = ev.getX(); touchPoint.y = ev.getY(); break; case MotionEvent.ACTION_MOVE: int height = params.height; // 滑动控件移动事件 float distance = ev.getY() - touchPoint.y; // 最大高度，不能向下拖动 if (height >= changeViewMaxHeight && distance > 0) { touchPoint.y = ev.getY(); break; } // 已经隐藏 不能向上滑动 if (height <= 0 && distance < 0) { touchPoint.y = ev.getY(); break; } // listview到达顶部才可以向下拖动 if (distance > 0 && scrollView.getFirstVisiblePosition() != 0) { touchPoint.y = ev.getY(); break; } height = Math.round(height + distance); if (height > changeViewMaxHeight) { height = changeViewMaxHeight; } if (height <= 0 && distance < 0) { height = 0; // TODO onhide } params.height = height; changeView.requestLayout(); touchPoint.x = ev.getX(); touchPoint.y = ev.getY(); break; case MotionEvent.ACTION_CANCEL: case MotionEvent.ACTION_UP: // 高度超过一半，自动隐藏 int[] values = null; // 向上滑动,剩余位置不足一半 if (params.height <= changeViewMaxHeight / 2) { values = new int[] { params.height, 0 }; } else { values = new int[] { params.height, changeViewMaxHeight }; } if (null != values) { ValueAnimator anim = ObjectAnimator.ofInt(changeView, "translationY", values); anim.addUpdateListener(new AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator animation) { int value = (int) animation.getAnimatedValue(); params.height = value; changeView.requestLayout(); } }); anim.setDuration(250); anim.setTarget(changeView); anim.start(); } break; } return true; } @Override public boolean dispatchTouchEvent(MotionEvent ev) { // 直接拦截事件 this.onTouchEvent(ev); return super.dispatchTouchEvent(ev); } private boolean isScrollViewTouch(MotionEvent ev) { float x = ev.getX(); float y = ev.getY(); return (x >= scrollViewRect.left && x <= scrollViewRect.right) && (y >= scrollViewRect.top && y <= scrollViewRect.bottom); } /** * @return Whether it is possible for the child view of this layout to * scroll up. Override this if the child view is a custom view. */ public boolean canChildScrollUp() { if (android.os.Build.VERSION.SDK_INT < 14) { if (scrollView instanceof AbsListView) { final AbsListView absListView = (AbsListView) scrollView; return absListView.getChildCount() > 0 && (absListView.getFirstVisiblePosition() > 0 || absListView.getChildAt(0).getTop() < absListView.getPaddingTop()); } else { return ViewCompat.canScrollVertically(scrollView, -1) || scrollView.getScrollY() > 0; } } else { return ViewCompat.canScrollVertically(scrollView, -1); } } @Override public void onScrollStateChanged(AbsListView view, int scrollState) { // TODO Auto-generated method stub } @Override public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { // TODO Auto-generated method stub } }