Java tutorial
/** * Copyright 2015 bingoogolapple * <p/> * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * <p/> * http://www.apache.org/licenses/LICENSE-2.0 * <p/> * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.chni.lidong.androidtestdemo.refresh; import android.content.Context; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentPagerAdapter; import android.support.v4.app.FragmentStatePagerAdapter; import android.support.v4.view.PagerAdapter; import android.support.v4.view.ViewPager; import android.support.v7.widget.RecyclerView; import android.util.AttributeSet; import android.view.MotionEvent; import android.view.VelocityTracker; import android.view.View; import android.view.ViewConfiguration; import android.webkit.WebView; import android.widget.AbsListView; import android.widget.LinearLayout; import android.widget.OverScroller; import android.widget.ScrollView; /** * : :bingoogolapple@gmail.com * :15/10/28 ?2:32 * ??: */ public class BGAStickyNavLayout extends LinearLayout { private View mHeaderView; private View mNavView; private View mContentView; private View mDirectNormalView; private RecyclerView mDirectRecyclerView; private AbsListView mDirectAbsListView; private ScrollView mDirectScrollView; private WebView mDirectWebView; private ViewPager mDirectViewPager; private View mNestedContentView; private View mNestedNormalView; private RecyclerView mNestedRecyclerView; private AbsListView mNestedAbsListView; private ScrollView mNestedScrollView; private WebView mNestedWebView; private OverScroller mOverScroller; private VelocityTracker mVelocityTracker; private int mTouchSlop; private int mMaximumVelocity; private int mMinimumVelocity; private boolean mIsInControl = true; private float mLastDispatchY; private float mLastTouchY; public BGARefreshLayout mRefreshLayout; public BGAStickyNavLayout(Context context, AttributeSet attrs) { super(context, attrs); init(context); } private void init(Context context) { setOrientation(VERTICAL); mOverScroller = new OverScroller(context); final ViewConfiguration configuration = ViewConfiguration.get(context); mTouchSlop = configuration.getScaledTouchSlop(); mMaximumVelocity = configuration.getScaledMaximumFlingVelocity(); mMinimumVelocity = configuration.getScaledMinimumFlingVelocity(); } @Override public void setOrientation(int orientation) { if (VERTICAL == orientation) { super.setOrientation(VERTICAL); } } @Override public void onFinishInflate() { super.onFinishInflate(); if (getChildCount() != 3) { throw new IllegalStateException( BGAStickyNavLayout.class.getSimpleName() + "??"); } mHeaderView = getChildAt(0); mNavView = getChildAt(1); mContentView = getChildAt(2); if (mContentView instanceof AbsListView) { mDirectAbsListView = (AbsListView) mContentView; mDirectAbsListView.setOnScrollListener(mLvOnScrollListener); } else if (mContentView instanceof RecyclerView) { mDirectRecyclerView = (RecyclerView) mContentView; mDirectRecyclerView.addOnScrollListener(mRvOnScrollListener); } else if (mContentView instanceof ScrollView) { mDirectScrollView = (ScrollView) mContentView; } else if (mContentView instanceof WebView) { mDirectWebView = (WebView) mContentView; } else if (mContentView instanceof ViewPager) { mDirectViewPager = (ViewPager) mContentView; mDirectViewPager.addOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() { @Override public void onPageSelected(int position) { regetNestedContentView(); } }); } else { mDirectNormalView = mContentView; } } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); measureChild(mContentView, widthMeasureSpec, MeasureSpec .makeMeasureSpec(MeasureSpec.getSize(heightMeasureSpec) - getNavViewHeight(), MeasureSpec.EXACTLY)); } @Override public void computeScroll() { if (mOverScroller.computeScrollOffset()) { scrollTo(0, mOverScroller.getCurrY()); invalidate(); } } public void fling(int velocityY) { mOverScroller.fling(0, getScrollY(), 0, velocityY, 0, 0, 0, getHeaderViewHeight()); invalidate(); } @Override public void scrollTo(int x, int y) { if (y < 0) { y = 0; } int headerViewHeight = getHeaderViewHeight(); if (y > headerViewHeight) { y = headerViewHeight; } if (y != getScrollY()) { super.scrollTo(x, y); } } /** * ?topMarginbottomMargin * * @return */ private int getHeaderViewHeight() { MarginLayoutParams layoutParams = (MarginLayoutParams) mHeaderView.getLayoutParams(); return mHeaderView.getMeasuredHeight() + layoutParams.topMargin + layoutParams.bottomMargin; } /** * ?topMarginbottomMargin * * @return */ private int getNavViewHeight() { MarginLayoutParams layoutParams = (MarginLayoutParams) mNavView.getLayoutParams(); return mNavView.getMeasuredHeight() + layoutParams.topMargin + layoutParams.bottomMargin; } /** * ???? * * @return */ private boolean isHeaderViewCompleteInvisible() { // 0x1y int[] location = new int[2]; getLocationOnScreen(location); int contentOnScreenTopY = location[1] + getPaddingTop(); mNavView.getLocationOnScreen(location); MarginLayoutParams params = (MarginLayoutParams) mNavView.getLayoutParams(); int navViewTopOnScreenY = location[1] - params.topMargin; if (navViewTopOnScreenY == contentOnScreenTopY) { return true; } else { return false; } } private void initVelocityTrackerIfNotExists() { if (mVelocityTracker == null) { mVelocityTracker = VelocityTracker.obtain(); } } private void recycleVelocityTracker() { if (mVelocityTracker != null) { mVelocityTracker.recycle(); mVelocityTracker = null; } } @Override public boolean dispatchTouchEvent(MotionEvent ev) { float currentTouchY = ev.getY(); switch (ev.getAction()) { case MotionEvent.ACTION_DOWN: mLastDispatchY = currentTouchY; break; case MotionEvent.ACTION_MOVE: float differentY = currentTouchY - mLastDispatchY; mLastDispatchY = currentTouchY; if (isContentViewToTop() && isHeaderViewCompleteInvisible()) { if (differentY >= 0 && !mIsInControl) { mIsInControl = true; return resetDispatchTouchEvent(ev); } if (differentY <= 0 && mIsInControl) { mIsInControl = false; return resetDispatchTouchEvent(ev); } } break; } return super.dispatchTouchEvent(ev); } private boolean resetDispatchTouchEvent(MotionEvent ev) { MotionEvent newEvent = MotionEvent.obtain(ev); ev.setAction(MotionEvent.ACTION_CANCEL); dispatchTouchEvent(ev); newEvent.setAction(MotionEvent.ACTION_DOWN); return dispatchTouchEvent(newEvent); } @Override public boolean onInterceptTouchEvent(MotionEvent ev) { float currentTouchY = ev.getY(); switch (ev.getAction()) { case MotionEvent.ACTION_DOWN: mLastTouchY = currentTouchY; break; case MotionEvent.ACTION_MOVE: float differentY = currentTouchY - mLastTouchY; if (Math.abs(differentY) > mTouchSlop) { if (!isHeaderViewCompleteInvisible() || (isContentViewToTop() && isHeaderViewCompleteInvisible() && mIsInControl)) { mLastTouchY = currentTouchY; return true; } } break; } return super.onInterceptTouchEvent(ev); } @Override public boolean onTouchEvent(MotionEvent event) { initVelocityTrackerIfNotExists(); mVelocityTracker.addMovement(event); float currentTouchY = event.getY(); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: if (!mOverScroller.isFinished()) { mOverScroller.abortAnimation(); } mLastTouchY = currentTouchY; break; case MotionEvent.ACTION_MOVE: float differentY = currentTouchY - mLastTouchY; mLastTouchY = currentTouchY; if (Math.abs(differentY) > 0) { scrollBy(0, (int) -differentY); } break; case MotionEvent.ACTION_CANCEL: recycleVelocityTracker(); if (!mOverScroller.isFinished()) { mOverScroller.abortAnimation(); } break; case MotionEvent.ACTION_UP: mVelocityTracker.computeCurrentVelocity(1000, mMaximumVelocity); int initialVelocity = (int) mVelocityTracker.getYVelocity(); if ((Math.abs(initialVelocity) > mMinimumVelocity)) { fling(-initialVelocity); } recycleVelocityTracker(); break; } return true; } public boolean isContentViewToTop() { if (mDirectNormalView != null) { return true; } if (BGARefreshScrollingUtil.isScrollViewOrWebViewToTop(mDirectWebView)) { return true; } if (BGARefreshScrollingUtil.isScrollViewOrWebViewToTop(mDirectScrollView)) { return true; } if (BGARefreshScrollingUtil.isAbsListViewToTop(mDirectAbsListView)) { return true; } if (BGARefreshScrollingUtil.isRecyclerViewToTop(mDirectRecyclerView)) { return true; } if (mDirectViewPager != null) { return isViewPagerContentViewToTop(); } return false; } private boolean isViewPagerContentViewToTop() { if (mNestedContentView == null) { regetNestedContentView(); } if (mDirectNormalView != null) { return true; } if (BGARefreshScrollingUtil.isScrollViewOrWebViewToTop(mNestedWebView)) { return true; } if (BGARefreshScrollingUtil.isScrollViewOrWebViewToTop(mNestedScrollView)) { return true; } if (BGARefreshScrollingUtil.isAbsListViewToTop(mNestedAbsListView)) { return true; } if (BGARefreshScrollingUtil.isRecyclerViewToTop(mNestedRecyclerView)) { return true; } return false; } /** * ?? */ private void regetNestedContentView() { int currentItem = mDirectViewPager.getCurrentItem(); PagerAdapter adapter = mDirectViewPager.getAdapter(); if (adapter instanceof FragmentPagerAdapter || adapter instanceof FragmentStatePagerAdapter) { Fragment item = (Fragment) adapter.instantiateItem(mDirectViewPager, currentItem); mNestedContentView = item.getView(); // ? mNestedNormalView = null; mNestedAbsListView = null; mNestedRecyclerView = null; mNestedScrollView = null; mNestedWebView = null; if (mNestedContentView instanceof AbsListView) { mNestedAbsListView = (AbsListView) mNestedContentView; mNestedAbsListView.setOnScrollListener(mLvOnScrollListener); if (!isHeaderViewCompleteInvisible()) { mNestedAbsListView.setSelection(0); } } else if (mNestedContentView instanceof RecyclerView) { mNestedRecyclerView = (RecyclerView) mNestedContentView; mNestedRecyclerView.removeOnScrollListener(mRvOnScrollListener); mNestedRecyclerView.addOnScrollListener(mRvOnScrollListener); if (!isHeaderViewCompleteInvisible()) { mNestedRecyclerView.scrollToPosition(0); } } else if (mNestedContentView instanceof ScrollView) { mNestedScrollView = (ScrollView) mNestedContentView; if (!isHeaderViewCompleteInvisible()) { mNestedScrollView.scrollTo(mNestedScrollView.getScrollX(), 0); } } else if (mNestedContentView instanceof WebView) { mNestedWebView = (WebView) mNestedContentView; if (!isHeaderViewCompleteInvisible()) { mNestedWebView.scrollTo(mNestedWebView.getScrollX(), 0); } } else { mNestedNormalView = mNestedContentView; } } else { throw new IllegalStateException(BGAStickyNavLayout.class.getSimpleName() + "?ViewPageradapterFragmentPagerAdapterFragmentStatePagerAdapter"); } } public void setRefreshLayout(BGARefreshLayout refreshLayout) { mRefreshLayout = refreshLayout; } private RecyclerView.OnScrollListener mRvOnScrollListener = new RecyclerView.OnScrollListener() { @Override public void onScrollStateChanged(RecyclerView recyclerView, int newState) { if ((newState == RecyclerView.SCROLL_STATE_IDLE || newState == RecyclerView.SCROLL_STATE_SETTLING) && mRefreshLayout != null && mRefreshLayout.shouldHandleRecyclerViewLoadingMore(recyclerView)) { mRefreshLayout.beginLoadingMore(); } } }; private AbsListView.OnScrollListener mLvOnScrollListener = new AbsListView.OnScrollListener() { @Override public void onScrollStateChanged(AbsListView absListView, int scrollState) { if ((scrollState == SCROLL_STATE_IDLE || scrollState == SCROLL_STATE_FLING) && mRefreshLayout != null && mRefreshLayout.shouldHandleAbsListViewLoadingMore(absListView)) { mRefreshLayout.beginLoadingMore(); } } @Override public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { } }; public boolean shouldHandleLoadingMore() { if (mRefreshLayout == null) { return false; } if (mDirectNormalView != null) { return true; } if (BGARefreshScrollingUtil.isWebViewToBottom(mDirectWebView)) { return true; } if (BGARefreshScrollingUtil.isScrollViewToBottom(mDirectScrollView)) { return true; } if (mDirectAbsListView != null) { return mRefreshLayout.shouldHandleAbsListViewLoadingMore(mDirectAbsListView); } if (mDirectRecyclerView != null) { return mRefreshLayout.shouldHandleRecyclerViewLoadingMore(mDirectRecyclerView); } if (mDirectViewPager != null) { if (mNestedContentView == null) { regetNestedContentView(); } if (mNestedNormalView != null) { return true; } if (BGARefreshScrollingUtil.isWebViewToBottom(mNestedWebView)) { return true; } if (BGARefreshScrollingUtil.isScrollViewToBottom(mNestedScrollView)) { return true; } if (mNestedAbsListView != null) { return mRefreshLayout.shouldHandleAbsListViewLoadingMore(mNestedAbsListView); } if (mNestedRecyclerView != null) { return mRefreshLayout.shouldHandleRecyclerViewLoadingMore(mNestedRecyclerView); } } return false; } public void scrollToBottom() { BGARefreshScrollingUtil.scrollToBottom(mDirectScrollView); BGARefreshScrollingUtil.scrollToBottom(mDirectRecyclerView); BGARefreshScrollingUtil.scrollToBottom(mDirectAbsListView); if (mDirectViewPager != null) { if (mNestedContentView == null) { regetNestedContentView(); } BGARefreshScrollingUtil.scrollToBottom(mNestedScrollView); BGARefreshScrollingUtil.scrollToBottom(mNestedRecyclerView); BGARefreshScrollingUtil.scrollToBottom(mNestedAbsListView); } } }