public class MyIndicator extends HorizontalScrollView implements ViewPager.OnPageChangeListener {
private ViewPager mViewPager;
private LinearLayout myLinearLayout;
MyOnPageChangeListener mListener;
private interface MyOnPageChangeListener {
void onPageScrolled(int position, float positionOffset, int positionOffsetPixels);
void onPageSelected(int position);
void onPageScrollStateChanged(int state);
}
private int oldSelected;
//为了让TextView能点击，我为每个TextView都设置了OnClickListener,
//就是获得目标标题栏的index，然后调用setCurrentItem()就可以了,这样就实现了点击滑动的效果，点击标题栏，Viewpager也会跟着翻页。
private final OnClickListener mTabClickListener=new OnClickListener() {
public void onClick(View view) {
MyTabView tabView=(MyTabView) view;
oldSelected=mViewPager.getCurrentItem();
final int newSelected=tabView.index;
setCurrentItem(newSelected);
}
};
public MyIndicator(Context context) {
super(context);
init(context);
}
public MyIndicator(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}
public MyIndicator(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init(context);
}
private void init(Context mcontext) {
setHorizontalScrollBarEnabled(false);//隐藏自带的滚动条
//添加linearLayout
myLinearLayout=new LinearLayout(mcontext);
myLinearLayout.setOrientation(LinearLayout.HORIZONTAL);
addView(myLinearLayout, new ViewGroup.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT));
}
public void setViewPager(ViewPager viewPager) {
setViewPager(viewPager, 0);
}
@SuppressWarnings("deprecation")
public void setViewPager(ViewPager viewPager, int initPos) {
if (mViewPager==viewPager) {
return;
}
if (mViewPager !=null) {
mViewPager.setOnPageChangeListener(null);
}
final PagerAdapter adapter=viewPager.getAdapter();
if (adapter==null) {
throw new IllegalStateException("ViewPager does not have adapter instance.");
}
mViewPager=viewPager;
viewPager.setOnPageChangeListener(this);
notifyDataSetChanged();
setCurrentItem(initPos);
}
private void notifyDataSetChanged() {
myLinearLayout.removeAllViews();
PagerAdapter mAdapter=mViewPager.getAdapter();
int count=mAdapter.getCount();
for (int i=0; i < count; i++) {
addTab(i, mAdapter.getPageTitle(i));
}
requestLayout();
}
private void addTab(int index, CharSequence text) {
MyTabView tabView=new MyTabView(getContext());
tabView.index=index;
tabView.setFocusable(true);
tabView.setOnClickListener(mTabClickListener);
tabView.setText(text);
tabView.setTextSize(22);
tabView.setTextColor(getContext().getResources().getColor(R.color.colorWhite));
tabView.setPadding(20, 0, 20, 0);
tabView.setTextAlignment(View.TEXT_ALIGNMENT_CENTER);
PagerAdapter mAdapter=mViewPager.getAdapter();
int screenWidth=getResources().getDisplayMetrics().widthPixels;
if (mAdapter.getCount() <=4) {
tabView.setWidth(screenWidth / mAdapter.getCount());
} else {
tabView.setWidth(screenWidth / 4);
}
myLinearLayout.addView(tabView);
}
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
@SuppressLint("NewApi")
private void animation(View view) {
ObjectAnimator scaleX=ObjectAnimator.ofFloat(view, "scaleX", 1f);
ObjectAnimator scaleY=ObjectAnimator.ofFloat(view, "scaleY", 1f);
ObjectAnimator fade=ObjectAnimator.ofFloat(view, "alpha", 1f);
AnimatorSet animSet=new AnimatorSet();
animSet.play(scaleX).with(scaleY).with(fade);
animSet.setDuration(500);
animSet.start();
}
private void animation2(View view) {
ObjectAnimator scaleX=ObjectAnimator.ofFloat(view, "scaleX", 0.8f);
ObjectAnimator scaleY=ObjectAnimator.ofFloat(view, "scaleY", 0.8f);
ObjectAnimator fade=ObjectAnimator.ofFloat(view, "alpha", 0.5f);
AnimatorSet animSet=new AnimatorSet();
animSet.play(scaleX).with(scaleY).with(fade);
animSet.setDuration(500);
animSet.start();
}
public void setCurrentItem(int item) {
if (mViewPager==null) {
throw new IllegalStateException("ViewPager has not been bound.");
}
int mSelectedTabIndex=item;
mViewPager.setCurrentItem(item);
final int tabCount=myLinearLayout.getChildCount();
for (int i=0; i < tabCount; i++) {//遍历标题，改变选中的背景
final View child=myLinearLayout.getChildAt(i);
final boolean isSelected=(i==item);
child.setSelected(isSelected);
if (isSelected) {
animation(child);
animateToTab(item);//动画效果
} else {
animation2(child);
child.setBackgroundColor(Color.TRANSPARENT);
}
}
}
private Runnable mTabSelector;
private void animateToTab(final int position) {
final View tabView=myLinearLayout.getChildAt(position);
if (mTabSelector !=null) {
removeCallbacks(mTabSelector);
}
mTabSelector=new Runnable() {
public void run() {
final int scrollPos=tabView.getLeft() - (getWidth() - tabView.getWidth()) / 2;//计算要滑动到的位置
smoothScrollTo(scrollPos, 0);
mTabSelector=null;
}
};
post(mTabSelector); //在主线程执行动画
}
public void setMyOnPageChangeListener(MyOnPageChangeListener listener) {
mListener=listener;
}
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
if (mListener !=null)
mListener.onPageScrolled(position, positionOffset, positionOffsetPixels);
}
@Override
public void onPageSelected(int position) {
setCurrentItem(position);
if (mListener !=null) mListener.onPageSelected(position);
}
@Override
public void onPageScrollStateChanged(int state) {
if (mListener !=null) mListener.onPageScrollStateChanged(state);
}
}
