Android 封装了ListView及各种View的下拉刷新和上拉加载

package com.quanquanle.view.pullrefresh; import com.quanquanle.view.pullrefresh.ILoadingLayout.State; import android.annotation.SuppressLint; import android.content.Context; import android.util.AttributeSet; import android.view.MotionEvent; import android.view.View; import android.view.ViewConfiguration; import android.view.ViewGroup; import android.view.ViewTreeObserver.OnGlobalLayoutListener; import android.view.animation.DecelerateInterpolator; import android.view.animation.Interpolator; import android.widget.FrameLayout; import android.widget.LinearLayout; /** * 这个实现了下拉刷新和上拉加载更多的功能 * * @author Li Hong * @since 2013-7-29 * @param <T> */ @SuppressLint("NewApi") public abstract class PullToRefreshBase<T extends View> extends LinearLayout implements IPullToRefresh<T> { /** * 定义了下拉刷新和上拉加载更多的接口。 * * @author Li Hong * @since 2013-7-29 */ public interface OnRefreshListener<V extends View> { /** * 下拉松手后会被调用 * * @param refreshView 刷新的View */ void onPullDownToRefresh(final PullToRefreshBase<V> refreshView); /** * 加载更多时会被调用或上拉时调用 * * @param refreshView 刷新的View */ void onPullUpToRefresh(final PullToRefreshBase<V> refreshView); } /**回滚的时间*/ private static final int SCROLL_DURATION = 150; /**阻尼系数*/ private static final float OFFSET_RADIO = 2.5f; /**上一次移动的点 */ private float mLastMotionY = -1; /**下拉刷新和加载更多的监听器 */ private OnRefreshListener<T> mRefreshListener; /**下拉刷新的布局 */ private LoadingLayout mHeaderLayout; /**上拉加载更多的布局*/ private LoadingLayout mFooterLayout; /**HeaderView的高度*/ private int mHeaderHeight; /**FooterView的高度*/ private int mFooterHeight; /**下拉刷新是否可用*/ private boolean mPullRefreshEnabled = true; /**上拉加载是否可用*/ private boolean mPullLoadEnabled = false; /**判断滑动到底部加载是否可用*/ private boolean mScrollLoadEnabled = false; /**是否截断touch事件*/ private boolean mInterceptEventEnable = true; /**表示是否消费了touch事件，如果是，则不调用父类的onTouchEvent方法*/ private boolean mIsHandledTouchEvent = false; /**移动点的保护范围值*/ private int mTouchSlop; /**下拉的状态*/ private State mPullDownState = State.NONE; /**上拉的状态*/ private State mPullUpState = State.NONE; /**可以下拉刷新的View*/ T mRefreshableView; /**平滑滚动的Runnable*/ private SmoothScrollRunnable mSmoothScrollRunnable; /**可刷新View的包装布局*/ private FrameLayout mRefreshableViewWrapper; /** * 构造方法 * * @param context context */ public PullToRefreshBase(Context context) { super(context); init(context, null); } /** * 构造方法 * * @param context context * @param attrs attrs */ public PullToRefreshBase(Context context, AttributeSet attrs) { super(context, attrs); init(context, attrs); } /** * 构造方法 * * @param context context * @param attrs attrs * @param defStyle defStyle */ public PullToRefreshBase(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); init(context, attrs); } /** * 初始化 * * @param context context */ private void init(Context context, AttributeSet attrs) { setOrientation(LinearLayout.VERTICAL); mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop(); mHeaderLayout = createHeaderLoadingLayout(context, attrs); mFooterLayout = createFooterLoadingLayout(context, attrs); mRefreshableView = createRefreshableView(context, attrs); if (null == mRefreshableView) { throw new NullPointerException("Refreshable view can not be null."); } addRefreshableView(context, mRefreshableView); addHeaderAndFooter(context); // 得到Header的高度，这个高度需要用这种方式得到，在onLayout方法里面得到的高度始终是0 getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() { @Override public void onGlobalLayout() { refreshLoadingViewsSize(); getViewTreeObserver().removeGlobalOnLayoutListener(this); } }); } /** * 初始化padding，我们根据header和footer的高度来设置top padding和bottom padding */ private void refreshLoadingViewsSize() { // 得到header和footer的内容高度，它将会作为拖动刷新的一个临界值，如果拖动距离大于这个高度 // 然后再松开手，就会触发刷新操作 int headerHeight = (null != mHeaderLayout) ? mHeaderLayout.getContentSize() : 0; int footerHeight = (null != mFooterLayout) ? mFooterLayout.getContentSize() : 0; if (headerHeight < 0) { headerHeight = 0; } if (footerHeight < 0) { footerHeight = 0; } mHeaderHeight = headerHeight; mFooterHeight = footerHeight; // 这里得到Header和Footer的高度，设置的padding的top和bottom就应该是header和footer的高度 // 因为header和footer是完全看不见的 headerHeight = (null != mHeaderLayout) ? mHeaderLayout.getMeasuredHeight() : 0; footerHeight = (null != mFooterLayout) ? mFooterLayout.getMeasuredHeight() : 0; if (0 == footerHeight) { footerHeight = mFooterHeight; } int pLeft = getPaddingLeft(); int pTop = getPaddingTop(); int pRight = getPaddingRight(); int pBottom = getPaddingBottom(); pTop = -headerHeight; pBottom = -footerHeight; setPadding(pLeft, pTop, pRight, pBottom); } @Override protected final void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); // We need to update the header/footer when our size changes refreshLoadingViewsSize(); // 设置刷新View的大小 refreshRefreshableViewSize(w, h); /** * As we're currently in a Layout Pass, we need to schedule another one * to layout any changes we've made here */ post(new Runnable() { @Override public void run() { requestLayout(); } }); } @Override public void setOrientation(int orientation) { if (LinearLayout.VERTICAL != orientation) { throw new IllegalArgumentException("This class only supports VERTICAL orientation."); } // Only support vertical orientation super.setOrientation(orientation); } @Override public final boolean onInterceptTouchEvent(MotionEvent event) { if (!isInterceptTouchEventEnabled()) { return false; } if (!isPullLoadEnabled() && !isPullRefreshEnabled()) { return false; } final int action = event.getAction(); if (action == MotionEvent.ACTION_CANCEL || action == MotionEvent.ACTION_UP) { mIsHandledTouchEvent = false; return false; } if (action != MotionEvent.ACTION_DOWN && mIsHandledTouchEvent) { return true; } switch (action) { case Moti