package com.dwtedx.qq.view; import android.content.Context; import android.util.AttributeSet; import android.util.Log; import android.view.LayoutInflater; import android.view.MotionEvent; import android.view.View; import android.view.ViewGroup; import android.widget.AbsListView; import android.widget.AbsListView.OnScrollListener; import android.widget.BaseAdapter; import android.widget.FrameLayout; import android.widget.LinearLayout; import android.widget.ListView; import android.widget.ProgressBar; import com.dwtedx.tst.R; public class DropdownListView extends ListView implements OnScrollListener { private static final String TAG = "listview"; private final static int RELEASE_To_REFRESH = 0; private final static int PULL_To_REFRESH = 1; private final static int REFRESHING = 2; private final static int DONE = 3; private final static int LOADING = 4; // 实际的padding的距离与界面上偏移距离的比例 private final static int RATIO = 3; private LayoutInflater inflater; private FrameLayout fl; private LinearLayout headView; // private View line; private ProgressBar progressBar; // private RotateAnimation animation; // private RotateAnimation reverseAnimation; // 用于保证startY的值在一个完整的touch事件中只被记录一次 private boolean isRecored; private int headContentWidth; private int headContentHeight; private int startY; private int firstItemIndex; private int state; private boolean isBack; private OnRefreshListenerHeader refreshListenerHeader; private boolean isRefreshableHeader; public DropdownListView(Context context) { super(context); init(context); } public DropdownListView(Context context, AttributeSet attrs) { super(context, attrs); init(context); } private void init(Context context) { setCacheColorHint(context.getResources().getColor(R.color.transparent)); inflater = LayoutInflater.from(context); fl = (FrameLayout)inflater.inflate(R.layout.dropdown_lv_head, null); headView = (LinearLayout) fl.findViewById(R.id.drop_down_head); progressBar = (ProgressBar) fl.findViewById(R.id.loading); measureView(headView); headContentHeight = headView.getMeasuredHeight(); headContentWidth = headView.getMeasuredWidth(); headView.setPadding(0, -1 * headContentHeight, 0, 0); headView.invalidate(); Log.v("size", "width:" + headContentWidth + " height:" + headContentHeight); addHeaderView(fl, null, false); // addHeaderView(headView, null, false); setOnScrollListener(this); state = DONE; isRefreshableHeader = false; } public void onScroll(AbsListView arg0, int firstVisiableItem, int arg2, int arg3) { firstItemIndex = firstVisiableItem; } public void onScrollStateChanged(AbsListView arg0, int scrollState) { if (scrollState == OnScrollListener.SCROLL_STATE_IDLE) { // 判断滚动到底部 } } public boolean onTouchEvent(MotionEvent event) { if (isRefreshableHeader) { switch (event.getAction()) { case MotionEvent.ACTION_DOWN: if (firstItemIndex == 0 && !isRecored) { isRecored = true; startY = (int) event.getY(); Log.v(TAG, "在down时候记录当前位置‘"); } break; case MotionEvent.ACTION_UP: if (state != REFRESHING && state != LOADING) { if (state == DONE) { // 什么都不做 } if (state == PULL_To_REFRESH) { state = DONE; changeHeaderViewByState(); Log.v(TAG, "由下拉刷新状态，到done状态"); } if (state == RELEASE_To_REFRESH) { state = REFRESHING; changeHeaderViewByState(); // recoverLine(); onRefresh(); Log.v(TAG, "由松开刷新状态，到done状态"); } } isRecored = false; isBack = false; break; case MotionEvent.ACTION_MOVE: int tempY = (int) event.getY(); if (!isRecored && firstItemIndex == 0) { Log.v(TAG, "在move时候记录下位置"); isRecored = true; startY = tempY; } if (state != REFRESHING && isRecored && state != LOADING) { // 保证在设置padding的过程中，当前的位置一直是在head，否则如果当列表超出屏幕的话，当在上推的时候，列表会同时进行滚动 // 可以松手去刷新了 if (state == RELEASE_To_REFRESH) { setSelection(0); // 往上推了，推到了屏幕足够掩盖head的程度，但是还没有推到全部掩盖的地步 if (((tempY - startY) / RATIO < headContentHeight) && (tempY - startY) > 0) { state = PULL_To_REFRESH; changeHeaderViewByState(); Log.v(TAG, "由松开刷新状态转变到下拉刷新状态"); } // 一下子推到顶了 else if (tempY - startY <= 0) { state = DONE; changeHeaderViewByState(); Log.v(TAG, "由松开刷新状态转变到done状态"); } // 往下拉了，或者还没有上推到屏幕顶部掩盖head的地步 else { // 不用进行特别的操作，只用更新paddingTop的值就行了 } } // 还没有到达显示松开刷新的时候,DONE或者是PULL_To_REFRESH状态 if (state == PULL_To_REFRESH) { setSelection(0); // 下拉到可以进入RELEASE_TO_REFRESH的状态 if ((tempY - startY) / RATIO >= headContentHeight) { state = RELEASE_To_REFRESH; isBack = true; changeHeaderViewByState(); Log.v(TAG, "由done或者下拉刷新状态转变到松开刷新"); } // 上推到顶了 else if (tempY - startY <= 0) { state = DONE; changeHeaderViewByState(); Log.v(TAG, "由DOne或者下拉刷新状态转变到done状态"); } } // done状态下 if (state == DONE) { if (tempY - startY > 0) { state = PULL_To_REFRESH; changeHeaderViewByState(); } } // 更新headView的size if (state == PULL_To_REFRESH) { headView.setPadding(0, -1 * headContentHeight + (tempY - startY) / RATIO, 0, 0); } // 更新headView的paddingTop if (state == RELEASE_To_REFRESH) { headView.setPadding(0, (tempY - startY) / RATIO - headContentHeight, 0, 0); } } break; } } return super.onTouchEvent(event); } // 当状态改变时候，调用该方法，以更新界面 private void changeHeaderViewByState() { switch (state) { case RELEASE_To_REFRESH: progressBar.setVisibility(View.VISIBLE); Log.v(TAG, "当前状态，松开刷新"); break; case PULL_To_REFRESH: progressBar.setVisibility(View.VISIBLE); // 是由RELEASE_To_REFRESH状态转变来的 if (isBack) { isBack = false; } else { } Log.v(TAG, "当前状态，下拉刷新"); break; case REFRESHING: headView.setPadding(0, 0, 0, 0); progressBar.setVisibility(View.VISIBLE); Log.v(TAG, "当前状态,正在刷新..."); break; case DONE: headView.setPadding(0, -1 * headContentHeight, 0, 0); progressBar.setVisibility(View.GONE); Log.v(TAG, "当前状态，done"); break; } } public void setOnRefreshListenerHead( OnRefreshListenerHeader refreshListenerHeader) { this.refreshListenerHeader = refreshListenerHeader; isRefreshableHeader = true; } public interface OnRefreshListenerHeader { public void onRefresh(); } public interface OnRefreshListenerFooter { public void onRefresh(); } public void onRefreshCompleteHeader() { state = DONE; changeHeaderViewByState(); } private void onRefresh() { if (refreshListenerHeader != null) { refreshListenerHeader.onRefresh(); } } // 此方法直接照搬自网络上的一个下拉刷新的demo，此处是“估计”headView的width以及height private void measureView(View child) { ViewGroup.LayoutParams p = child.getLayoutParams(); if (p == null) { p = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT); } int childWidthSpec = ViewGroup.getChildMeasureSpec(0, 0 + 0, p.width); int lpHeight = p.height; int childHeightSpec; if (lpHeight > 0) { childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); } else { childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); } child.measure(childWidthSpec, childHeightSpec); } public void setAdapter(BaseAdapter adapter) { super.setAdapter(adapter); } }
对应头部布局：
<?xml version="1.0" encoding="utf-8"?> <!-- ListView的头部 --> <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="wrap_content" > <View android:id="@+id/line" android:layout_width="0.2dip" android:layout_height="match_parent" android:layout_gravity="center_horizontal" android:background="@color/gray" /> <LinearLayout android:id="@+id/drop_down_head" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_gravity="bottom" android:gravity="center_horizontal" android:orientation="vertical" > <View android:layout_width="0.2dip" android:layout_height="20dip" android:layout_gravity="center_horizontal" android:background="@color/gray" /> <ProgressBar android:id="@+id/loading" android:layout_width="20dip" android:layout_height="20dip" android:background="@drawable/circle_shape" android:indeterminateDrawable="@drawable/loading" /> </LinearLayout> </FrameLayout>
