TabBarView.java

package com.com.mr_wrong.test;

import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
import android.widget.LinearLayout;

public class TabBarView extends LinearLayout {
	public interface IconTabProvider {
		public int getPageIconResId(int position);
	}
	private static final int STRIP_HEIGHT = 6;

	public final Paint mPaint;

	private int mStripHeight;
	private float mOffset = 0f;
	public static int mSelectedTab = 0;
	public ViewPager pager;

	public static int tabCount;
	private final PageListener pageListener = new PageListener();
	public OnPageChangeListener delegatePageListener;

	private View child;

	private View nextChild;

	public static int a;

	public TabBarView(Context context) {
		this(context, null);
	}

	public TabBarView(Context context, AttributeSet attrs) {
		this(context, attrs, android.R.attr.actionBarTabBarStyle);
	}

	public TabBarView(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);

		setWillNotDraw(false);

		mPaint = new Paint();
		mPaint.setColor(Color.WHITE);
		mPaint.setAntiAlias(true);

		mStripHeight = (int) (STRIP_HEIGHT * getResources().getDisplayMetrics().density + .5f);
	}

	public void setStripColor(int color) {
		if (mPaint.getColor() != color) {
			mPaint.setColor(color);
			invalidate();
		}
	}

	public void setStripHeight(int height) {
		if (mStripHeight != height) {
			mStripHeight = height;
			invalidate();
		}
	}

	public void setSelectedTab(int tabIndex) {
		if (tabIndex < 0) {
			tabIndex = 0;
		}
		final int childCount = getChildCount();
		if (tabIndex >= childCount) {
			tabIndex = childCount - 1;
		}
		if (mSelectedTab != tabIndex) {
			mSelectedTab = tabIndex;
			invalidate();
		}
	}

	public void setOffset(int position, float offset) {
		if (mOffset != offset) {
			mOffset = offset;
			invalidate();
		}
	}

	@Override
	protected void onDraw(Canvas canvas) {
		super.onDraw(canvas);
		// Draw the strip manually
		child = getChildAt(mSelectedTab);
		int height = getHeight();
		if (child != null) {
			float left = child.getLeft();
			//Log.e("child.getLeft()==========", child.getLeft()+"");
			float right = child.getRight();
			if (mOffset >  0f && mSelectedTab < tabCount - 1 ) {
				nextChild = getChildAt(mSelectedTab + 1);
				if (nextChild != null) {
					final float nextTabLeft = nextChild.getLeft();
					//Log.e("nextChild.getLeft()==========", nextChild.getLeft()+"");
					final float nextTabRight = nextChild.getRight();
					left =  (mOffset * nextTabLeft + (1f - mOffset) * left);
					right = (mOffset * nextTabRight + (1f - mOffset) * right);
				}
			}
			canvas.drawRect(left, height - mStripHeight, right, height, mPaint);
		}
	}

	public void setViewPager(ViewPager pager) {
		this.pager = pager;

		if (pager.getAdapter() == null) {
			throw new IllegalStateException("ViewPager does not have adapter instance.");
		}

		pager.setOnPageChangeListener(pageListener);

		notifyDataSetChanged();
	}

	private class PageListener implements OnPageChangeListener {

		@Override
		public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

			mSelectedTab = position;
			mOffset = positionOffset;
			//Log.e("mOffset==========", mOffset+"");
			invalidate();

			if (delegatePageListener != null) {
				delegatePageListener.onPageScrolled(position, positionOffset, positionOffsetPixels);
			}
		}

		@Override
		public void onPageScrollStateChanged(int state) {
			if (state == ViewPager.SCROLL_STATE_IDLE) {

			}

			if (delegatePageListener != null) {
				delegatePageListener.onPageScrollStateChanged(state);
			}
		}

		@Override
		public void onPageSelected(int position) {
			if (delegatePageListener != null) {
				delegatePageListener.onPageSelected(position);
			}
		}

	}

	public void notifyDataSetChanged() {

		this.removeAllViews();

		tabCount = pager.getAdapter().getCount();

		for (int i = 0; i < tabCount; i++) {

			if(getResources().getConfiguration().orientation==1){
				//横排
				addTabViewP(i, pager.getAdapter().getPageTitle(i).toString(),
						((IconTabProvider) pager.getAdapter()).getPageIconResId(i));

			}else{

				addTabViewL(i, pager.getAdapter().getPageTitle(i).toString(),
						((IconTabProvider) pager.getAdapter()).getPageIconResId(i));

			}
		}

		getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {

			@SuppressLint("NewApi")
			@Override
			public void onGlobalLayout() {

				getViewTreeObserver().removeOnGlobalLayoutListener(this);

				mSelectedTab = pager.getCurrentItem();

			}
		});

	}
	/**
	 * 横排
	 * @param i
	 * @param string
	 * @param pageIconResId
	 */
	private void addTabViewL(final int i, String string, int pageIconResId) {
		TabView tab = new TabView(getContext());
		//tab.setIcon(pageIconResId);
		tab.setText(string, pageIconResId);
		tab.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				pager.setCurrentItem(i);
			}
		});

		this.addView(tab);
	}

	/**
	 * 竖排
	 * @param i
	 * @param string
	 * @param pageIconResId
	 */
	private void addTabViewP(final int i, final String string, int pageIconResId) {
		final TabView tab = new TabView(getContext());
		tab.setIcon(pageIconResId);
		tab.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {

				pager.setCurrentItem(i);
			}
		});
		//长按显示文字
		CheatSheet.setup(tab, string);

		this.addView(tab);
	}

	public void setOnPageChangeListener(OnPageChangeListener listener) {
		this.delegatePageListener = listener;
	}


}