package com.hanju.video.app.test;
|
|
import android.content.Context;
|
import androidx.viewpager.widget.PagerAdapter;
|
import androidx.viewpager.widget.ViewPager;
|
import android.util.AttributeSet;
|
import android.view.MotionEvent;
|
import android.view.View;
|
import android.view.ViewGroup;
|
|
public class MyViewPager extends ViewPager implements Runnable {
|
|
private PagerAdapter pagerAdapter;
|
|
private static final int POST_DELAYED_TIME = 1000 * 5;
|
// 手指是否放在上面
|
private boolean touching;
|
|
// 更新数据需要获得myPagerAdapter
|
private PagerAdapter myPagerAdapter;
|
|
public MyViewPager(Context context, AttributeSet attrs) {
|
super(context, attrs);
|
// postDelayed(this, POST_DELAYED_TIME);
|
}
|
|
// 对setAdapter的数据进行包装
|
private class MyPagerAdapter extends PagerAdapter {
|
private PagerAdapter pa;
|
|
public MyPagerAdapter(PagerAdapter pa) {
|
this.pa = pa;
|
}
|
|
@Override
|
// 关键之一:修改Count长度
|
public int getCount() {
|
return pa.getCount() > 1 ? pa.getCount() + 2 : pa.getCount();
|
}
|
|
@Override
|
// 这里是关键之二:修改索引(如果不考虑内容问题可以全部加载进数组然后操作更简单)
|
public Object instantiateItem(ViewGroup container, int position) {
|
|
if (position == 0) {
|
return pa.instantiateItem(container, pa.getCount() - 1);
|
} else if (position == pa.getCount() + 1) {
|
return pa.instantiateItem(container, 0);
|
} else {
|
return pa.instantiateItem(container, position - 1);
|
}
|
}
|
|
@Override
|
public void destroyItem(ViewGroup container, int position, Object object) {
|
pa.destroyItem(container, position, object);
|
}
|
|
@Override
|
public boolean isViewFromObject(View arg0, Object arg1) {
|
return pa.isViewFromObject(arg0, arg1);
|
}
|
}
|
|
// 包装setOnPageChangeListener的数据
|
private class MyOnPageChangeListener implements OnPageChangeListener {
|
private OnPageChangeListener listener;
|
// 是否已经提前触发了OnPageSelected事件
|
private boolean alreadyTriggerOnPageSelected;
|
|
public MyOnPageChangeListener(OnPageChangeListener listener) {
|
this.listener = listener;
|
}
|
|
@Override
|
// 关键之三:
|
public void onPageScrollStateChanged(int arg0) {
|
if (arg0 == SCROLL_STATE_IDLE) {
|
if (getCurrentItem() + 1 == 0) {
|
setCurrentItem(pagerAdapter.getCount() - 1, false);
|
} else if (getCurrentItem() + 1 == pagerAdapter.getCount() + 1) {
|
setCurrentItem(0, false);
|
}
|
}
|
|
listener.onPageScrollStateChanged(arg0);
|
}
|
|
@Override
|
public void onPageScrolled(int arg0, float arg1, int arg2) {
|
listener.onPageScrolled(arg0, arg1, arg2);
|
}
|
|
@Override
|
// 关键四:
|
public void onPageSelected(int arg0) {
|
if (arg0 == 0) {
|
listener.onPageSelected(pagerAdapter.getCount() - 1);
|
alreadyTriggerOnPageSelected = true;
|
} else if (arg0 == pagerAdapter.getCount() + 1) {
|
listener.onPageSelected(0);
|
alreadyTriggerOnPageSelected = true;
|
} else {
|
if (!alreadyTriggerOnPageSelected) {
|
listener.onPageSelected(arg0 - 1);
|
}
|
alreadyTriggerOnPageSelected = false;
|
}
|
|
}
|
|
}
|
|
@Override
|
public void setOnPageChangeListener(OnPageChangeListener listener) {
|
super.setOnPageChangeListener(listener == null ? null
|
: new MyOnPageChangeListener(listener));
|
}
|
|
@Override
|
public void setAdapter(PagerAdapter arg0) {
|
myPagerAdapter = arg0 == null ? null : new MyPagerAdapter(arg0);
|
super.setAdapter(myPagerAdapter);
|
|
if (arg0 != null && arg0.getCount() != 0) {
|
setCurrentItem(0, false);
|
}
|
this.pagerAdapter = arg0;
|
}
|
|
@Override
|
// 兼容PageIndicator
|
public PagerAdapter getAdapter() {
|
return pagerAdapter;
|
}
|
|
public PagerAdapter getMyPagerAdapter() {
|
return myPagerAdapter;
|
}
|
|
@Override
|
public int getCurrentItem() {
|
return super.getCurrentItem() - 1;
|
}
|
|
@Override
|
public void setCurrentItem(int item) {
|
setCurrentItem(item, true);
|
}
|
|
@Override
|
public void setCurrentItem(int item, boolean smoothScroll) {
|
super.setCurrentItem(item + 1, smoothScroll);
|
}
|
|
@Override
|
// 自动滚动关键
|
public void run() {
|
if (getAdapter() != null && getAdapter().getCount() > 1 && !touching) {
|
setCurrentItem(getCurrentItem() + 1, true);
|
}
|
postDelayed(this, POST_DELAYED_TIME);
|
}
|
|
@Override
|
public boolean onTouchEvent(MotionEvent event) {
|
if (event.getAction() == MotionEvent.ACTION_DOWN) {
|
this.touching = true;
|
} else if (event.getAction() == MotionEvent.ACTION_UP
|
|| event.getAction() == MotionEvent.ACTION_CANCEL) {
|
this.touching = false;
|
}
|
|
if (isEnabled()) {
|
if (getCurrentItem() <= 0 && getChildCount() == 0) {
|
return false;
|
}
|
return super.onTouchEvent(event);
|
} else {
|
return false;
|
}
|
}
|
}
|
