Android Navigation TabBar控件实现多彩标签栏

先看看效果图：

源码下载：Android Navigation TabBar控件实现多彩标签栏

代码：

MainActivity.java

package com.bzu.gxs.meunguide;

import android.app.Activity;
import android.graphics.Color;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import java.util.ArrayList;

public class MainActivity extends Activity{

@Override
 protected void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
   setContentView(R.layout.activity_main);
   initUI();
 }

private void initUI() {

final ViewPager viewPager = (ViewPager) findViewById(R.id.vp_horizontal_ntb);
   viewPager.setAdapter(new PagerAdapter() {
     @Override
     public int getCount() {
       return 5;
     }

@Override
     public boolean isViewFromObject(View view, Object object) {
       return view.equals(object);
     }

@Override
     public void destroyItem(final View container,final int position,final Object object) {
       ((ViewPager)container).removeView((View)object);
     }

@Override
     public Object instantiateItem(final ViewGroup container,final int position) {
       final View view = LayoutInflater.from(getBaseContext()).inflate(R.layout.activity_item,null,false);

final TextView textView = (TextView) view.findViewById(R.id.txt_vp_item_page);
       textView.setText(String.format("界面 ％d",position));
       container.addView(view);
       return view;
     }
   });

//
   final String[] colors = getResources().getStringArray(R.array.default_preview);
   final NavigationTabBar navigationTabBar = (NavigationTabBar) findViewById(R.id.ntb_horizontal);
   final ArrayList<NavigationTabBar.Model> models = new ArrayList<>();

models.add(new NavigationTabBar.Model(
       getResources().getDrawable(R.drawable.ic_first), Color.parseColor(colors[0]),"One"));
   models.add(new NavigationTabBar.Model(
       getResources().getDrawable(R.drawable.ic_second),Color.parseColor(colors[1]),"Two"));
   models.add(new NavigationTabBar.Model(
       getResources().getDrawable(R.drawable.ic_third),Color.parseColor(colors[2]),"Thirt"));
   models.add(new NavigationTabBar.Model(
       getResources().getDrawable(R.drawable.ic_fourth),Color.parseColor(colors[3]),"Fourth"));
   models.add(new NavigationTabBar.Model(
       getResources().getDrawable(R.drawable.ic_fifth),Color.parseColor(colors[4]),"Fifth"));

navigationTabBar.setModels(models);
   navigationTabBar.setViewPager(viewPager,2);
   navigationTabBar.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
     @Override
     public void onPageScrolled(final int position, final float positionOffset, final int positionOffsetPixels) {

}

@Override
     public void onPageSelected(final int position) {
       navigationTabBar.getModels().get(position).hideBadge();
     }

@Override
     public void onPageScrollStateChanged(final int state) {

}
   });

navigationTabBar.post(new Runnable() {
     @Override
     public void run() {
       final View bgNavigationTaBar = findViewById(R.id.bg_ntb_horizontal);
       bgNavigationTaBar.getLayoutParams().height = (int) navigationTabBar.getHeight();

}
   });

navigationTabBar.postDelayed(new Runnable() {
     @Override
     public void run() {
       for (int i=0; i<navigationTabBar.getModels().size() ; i++){
         final NavigationTabBar.Model model = navigationTabBar.getModels().get(i);
         switch (i){
           case 0:
             model.setBadgeTitle("Gxs1");
             break;
           case 1:
             model.setBadgeTitle("Gxs2");
             break;
           case 2:
             model.setBadgeTitle("Gxs3");
             break;
           case 3:
             model.setBadgeTitle("Gxs4");
             break;
           case 4:
             model.setBadgeTitle("Gxs5");
             break;
           default:
             break;
         }
         navigationTabBar.postDelayed(new Runnable() {
           @Override
           public void run() {
             model.showBadge();
           }
         },i * 100);
       }
     }
   },500);

}
}

NavigationTabBar.java

package com.bzu.gxs.meunguide;

import android.animation.Animator;
import android.animation.ValueAnimator;
import android.content.Context;
import android.content.res.Configuration;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffColorFilter;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.Typeface;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.Parcel;
import android.os.Parcelable;
import android.support.v4.view.ViewPager;
import android.text.TextPaint;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.animation.AccelerateDecelerateInterpolator;
import android.view.animation.AccelerateInterpolator;
import android.view.animation.DecelerateInterpolator;
import android.view.animation.Interpolator;
import android.view.animation.LinearInterpolator;
import android.widget.Scroller;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;

/**
* Created by GXS on 2016/5/7.
*/

public class NavigationTabBar extends View implements ViewPager.OnPageChangeListener {

// NTP constants
 private final static String PREVIEW_BADGE = "0";
 private final static String PREVIEW_TITLE = "Title";
 private final static int INVALID_INDEX = -1;

private final static int DEFAULT_BADGE_ANIMATION_DURATION = 200;
 private final static int DEFAULT_BADGE_REFRESH_ANIMATION_DURATION = 100;
 private final static int DEFAULT_ANIMATION_DURATION = 300;
 private final static int DEFAULT_INACTIVE_COLOR = Color.parseColor("#9f90af");
 private final static int DEFAULT_ACTIVE_COLOR = Color.WHITE;

private final static float MIN_FRACTION = 0.0f;
 private final static float NON_SCALED_FRACTION = 0.35f;
 private final static float MAX_FRACTION = 1.0f;

private final static int MIN_ALPHA = 0;
 private final static int MAX_ALPHA = 255;

private final static float ACTIVE_ICON_SCALE_BY = 0.3f;
 private final static float ICON_SIZE_FRACTION = 0.45f;

private final static float TITLE_ACTIVE_ICON_SCALE_BY = 0.2f;
 private final static float TITLE_ICON_SIZE_FRACTION = 0.45f;
 private final static float TITLE_ACTIVE_SCALE_BY = 0.2f;
 private final static float TITLE_SIZE_FRACTION = 0.2f;
 private final static float TITLE_MARGIN_FRACTION = 0.15f;

private final static float BADGE_HORIZONTAL_FRACTION = 0.5f;
 private final static float BADGE_VERTICAL_FRACTION = 0.75f;
 private final static float BADGE_TITLE_SIZE_FRACTION = 0.85f;

private final static int ALL_INDEX = 0;
 private final static int ACTIVE_INDEX = 1;

private final static int LEFT_INDEX = 0;
 private final static int CENTER_INDEX = 1;
 private final static int RIGHT_INDEX = 2;

private final static int TOP_INDEX = 0;
 private final static int BOTTOM_INDEX = 1;

private final static float LEFT_FRACTION = 0.25f;
 private final static float CENTER_FRACTION = 0.5f;
 private final static float RIGHT_FRACTION = 0.75f;

private final static Interpolator DECELERATE_INTERPOLATOR = new DecelerateInterpolator();
 private final static Interpolator ACCELERATE_INTERPOLATOR = new AccelerateInterpolator();

// NTP and pointer bounds
 private final RectF mBounds = new RectF();
 private final RectF mPointerBounds = new RectF();
 // Badge bounds and bg badge bounds
 private final Rect mBadgeBounds = new Rect();
 private final RectF mBgBadgeBounds = new RectF();

// Canvas, where all of other canvas will be merged
 private Bitmap mBitmap;
 private Canvas mCanvas;

// Canvas with icons
 private Bitmap mIconsBitmap;
 private Canvas mIconsCanvas;

// Canvas for our rect pointer
 private Bitmap mPointerBitmap;
 private Canvas mPointerCanvas;

// Main paint
 private final Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG) {
   {
     setDither(true);
     setStyle(Style.FILL);
   }
 };

// Pointer paint
 private final Paint mPointerPaint = new Paint(Paint.ANTI_ALIAS_FLAG) {
   {
     setDither(true);
     setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
   }
 };

// Icons paint
 private final Paint mIconPaint = new Paint(Paint.ANTI_ALIAS_FLAG) {
   {
     setDither(true);
   }
 };

// Paint for icon mask pointer
 private final Paint mIconPointerPaint = new Paint(Paint.ANTI_ALIAS_FLAG) {
   {
     setStyle(Style.FILL);
     setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
   }
 };

// Paint for model title
 private final Paint mModelTitlePaint = new TextPaint(Paint.ANTI_ALIAS_FLAG) {
   {
     setDither(true);
     setColor(Color.WHITE);
     setTextAlign(Align.CENTER);
   }
 };

// Paint for badge
 private final Paint mBadgePaint = new TextPaint(Paint.ANTI_ALIAS_FLAG) {
   {
     setDither(true);
     setTextAlign(Align.CENTER);
     setFakeBoldText(true);
   }
 };

// Variables for animator
 private final ValueAnimator mAnimator = new ValueAnimator();
 private final ResizeInterpolator mResizeInterpolator = new ResizeInterpolator();
 private int mAnimationDuration;

// NTP models
 private List<Model> mModels = new ArrayList<>();

// Variables for ViewPager
 private ViewPager mViewPager;
 private ViewPager.OnPageChangeListener mOnPageChangeListener;
 private int mScrollState;

// Tab listener
 private OnTabBarSelectedIndexListener mOnTabBarSelectedIndexListener;
 private ValueAnimator.AnimatorListener mAnimatorListener;

// Variables for sizes
 private float mModelSize;
 private int mIconSize;
 // Corners radius for rect mode
 private float mCornersRadius;

// Model title size and margin
 private float mModelTitleSize;
 private float mTitleMargin;

// Model badge title size and margin
 private float mBadgeMargin;
 private float mBadgeTitleSize;

// Model title mode: active ar all
 private TitleMode mTitleMode;
 // Model badge position: left, center or right
 private BadgePosition mBadgePosition;
 // Model badge gravity: top or bottom
 private BadgeGravity mBadgeGravity;

// Indexes
 private int mLastIndex = INVALID_INDEX;
 private int mIndex = INVALID_INDEX;
 // General fraction value
 private float mFraction;

// Coordinates of pointer
 private float mStartPointerX;
 private float mEndPointerX;
 private float mPointerLeftTop;
 private float mPointerRightBottom;

// Detect if model has title
 private boolean mIsTitled;
 // Detect if model has badge
 private boolean mIsBadged;
 // Detect if model icon scaled
 private boolean mIsScaled;
 // Detect if model badge have custom typeface
 private boolean mIsBadgeUseTypeface;
 // Detect if is bar mode or indicator pager mode
 private boolean mIsViewPagerMode;
 // Detect whether the horizontal orientation
 private boolean mIsHorizontalOrientation;
 // Detect if we move from left to right
 private boolean mIsResizeIn;
 // Detect if we get action down event
 private boolean mIsActionDown;
 // Detect if we get action down event on pointer
 private boolean mIsPointerActionDown;
 // Detect when we set index from tab bar nor from ViewPager
 private boolean mIsSetIndexFromTabBar;

// Color variables
 private int mInactiveColor;
 private int mActiveColor;

// Custom typeface
 private Typeface mTypeface;

public NavigationTabBar(final Context context) {
   this(context, null);
 }

public NavigationTabBar(final Context context, final AttributeSet attrs) {
   this(context, attrs, 0);
 }

public NavigationTabBar(final Context context, final AttributeSet attrs, final int defStyleAttr) {
   super(context, attrs, defStyleAttr);
   //Init NTB

// Always draw
   setWillNotDraw(false);
   // More speed!
   setLayerType(LAYER_TYPE_HARDWARE, null);

final TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.NavigationTabBar);
   try {
     setIsTitled(
         typedArray.getBoolean(R.styleable.NavigationTabBar_ntb_titled, false)
     );
     setIsBadged(
         typedArray.getBoolean(R.styleable.NavigationTabBar_ntb_badged, false)
     );
     setIsScaled(
         typedArray.getBoolean(R.styleable.NavigationTabBar_ntb_scaled, true)
     );
     setIsBadgeUseTypeface(
         typedArray.getBoolean(R.styleable.NavigationTabBar_ntb_badge_use_typeface, false)
     );
     setTitleMode(
         typedArray.getInt(R.styleable.NavigationTabBar_ntb_title_mode, ALL_INDEX)
     );
     setBadgePosition(
         typedArray.getInt(R.styleable.NavigationTabBar_ntb_badge_position, RIGHT_INDEX)
     );
     setBadgeGravity(
         typedArray.getInt(R.styleable.NavigationTabBar_ntb_badge_gravity, TOP_INDEX)
     );
     setTypeface(
         typedArray.getString(R.styleable.NavigationTabBar_ntb_typeface)
     );
     setInactiveColor(
         typedArray.getColor(
             R.styleable.NavigationTabBar_ntb_inactive_color, DEFAULT_INACTIVE_COLOR
         )
     );
     setActiveColor(
         typedArray.getColor(
             R.styleable.NavigationTabBar_ntb_active_color, DEFAULT_ACTIVE_COLOR
         )
     );
     setAnimationDuration(
         typedArray.getInteger(
             R.styleable.NavigationTabBar_ntb_animation_duration, DEFAULT_ANIMATION_DURATION
         )
     );
     setCornersRadius(
         typedArray.getDimension(R.styleable.NavigationTabBar_ntb_corners_radius, 0.0f)
     );

// Init animator
     mAnimator.setFloatValues(MIN_FRACTION, MAX_FRACTION);
     mAnimator.setInterpolator(new LinearInterpolator());
     mAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
       @Override
       public void onAnimationUpdate(final ValueAnimator animation) {
         updateIndicatorPosition((Float) animation.getAnimatedValue());
       }
     });

// Set preview models
     if (isInEditMode()) {
       // Get preview colors
       String[] previewColors = null;
       try {
         final int previewColorsId = typedArray.getResourceId(
             R.styleable.NavigationTabBar_ntb_preview_colors, 0
         );
         previewColors = previewColorsId == 0 ? null :
             typedArray.getResources().getStringArray(previewColorsId);
       } catch (Exception exception) {
         previewColors = null;
         exception.printStackTrace();
       } finally {
         if (previewColors == null)
           previewColors = typedArray.getResources().getStringArray(R.array.default_preview);

for (String previewColor : previewColors)
           mModels.add(new Model(null, Color.parseColor(previewColor)));
         requestLayout();
       }
     }
   } finally {
     typedArray.recycle();
   }
 }

public int getAnimationDuration() {
   return mAnimationDuration;
 }

public void setAnimationDuration(final int animationDuration) {
   mAnimationDuration = animationDuration;
   mAnimator.setDuration(mAnimationDuration);
   resetScroller();
 }

public List<Model> getModels() {
   return mModels;
 }

public void setModels(final List<Model> models) {
   //Set update listeners to badge model animation
   for (final Model model : models) {
     model.mBadgeAnimator.removeAllUpdateListeners();
     model.mBadgeAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
       @Override
       public void onAnimationUpdate(final ValueAnimator animation) {
         model.mBadgeFraction = (float) animation.getAnimatedValue();
         postInvalidate();
       }
     });
   }

mModels.clear();
   mModels = models;
   requestLayout();
 }

public boolean isTitled() {
   return mIsTitled;
 }

public void setIsTitled(final boolean isTitled) {
   mIsTitled = isTitled;
   requestLayout();
 }

public boolean isBadged() {
   return mIsBadged;
 }

public void setIsBadged(final boolean isBadged) {
   mIsBadged = isBadged;
   requestLayout();
 }

public boolean isScaled() {
   return mIsScaled;
 }

public void setIsScaled(final boolean isScaled) {
   mIsScaled = isScaled;
   requestLayout();
 }

public boolean isBadgeUseTypeface() {
   return mIsBadgeUseTypeface;
 }

public void setIsBadgeUseTypeface(final boolean isBadgeUseTypeface) {
   mIsBadgeUseTypeface = isBadgeUseTypeface;
   setBadgeTypeface();
   postInvalidate();
 }

public TitleMode getTitleMode() {
   return mTitleMode;
 }

private void setTitleMode(final int index) {
   switch (index) {
     case ACTIVE_INDEX:
       setTitleMode(TitleMode.ACTIVE);
       break;
     case ALL_INDEX:
     default:
       setTitleMode(TitleMode.ALL);
   }
 }

public void setTitleMode(final TitleMode titleMode) {
   mTitleMode = titleMode;
   postInvalidate();
 }

public BadgePosition getBadgePosition() {
   return mBadgePosition;
 }

private void setBadgePosition(final int index) {
   switch (index) {
     case LEFT_INDEX:
       setBadgePosition(BadgePosition.LEFT);
       break;
     case CENTER_INDEX:
       setBadgePosition(BadgePosition.CENTER);
       break;
     case RIGHT_INDEX:
     default:
       setBadgePosition(BadgePosition.RIGHT);
   }
 }

public void setBadgePosition(final BadgePosition badgePosition) {
   mBadgePosition = badgePosition;
   postInvalidate();
 }

public BadgeGravity getBadgeGravity() {
   return mBadgeGravity;
 }

private void setBadgeGravity(final int index) {
   switch (index) {
     case BOTTOM_INDEX:
       setBadgeGravity(BadgeGravity.BOTTOM);
       break;
     case TOP_INDEX:
     default:
       setBadgeGravity(BadgeGravity.TOP);
   }
 }

public void setBadgeGravity(final BadgeGravity badgeGravity) {
   mBadgeGravity = badgeGravity;
   requestLayout();
 }

public Typeface getTypeface() {
   return mTypeface;
 }

public void setTypeface(final String typeface) {
   Typeface tempTypeface;
   try {
     tempTypeface = Typeface.createFromAsset(getContext().getAssets(), typeface);
   } catch (Exception e) {
     tempTypeface = Typeface.create(Typeface.DEFAULT, Typeface.NORMAL);
     e.printStackTrace();
   }

setTypeface(tempTypeface);
 }

public void setTypeface(final Typeface typeface) {
   mTypeface = typeface;
   mModelTitlePaint.setTypeface(typeface);
   setBadgeTypeface();
   postInvalidate();
 }

private void setBadgeTypeface() {
   mBadgePaint.setTypeface(
       mIsBadgeUseTypeface ? mTypeface : Typeface.create(Typeface.DEFAULT, Typeface.NORMAL)
   );
 }

public int getActiveColor() {
   return mActiveColor;
 }

public void setActiveColor(final int activeColor) {
   mActiveColor = activeColor;
   mIconPointerPaint.setColor(activeColor);
   postInvalidate();
 }

public int getInactiveColor() {
   return mInactiveColor;
 }

public void setInactiveColor(final int inactiveColor) {
   mInactiveColor = inactiveColor;

// Set color filter to wrap icons with inactive color
   mIconPaint.setColorFilter(new PorterDuffColorFilter(inactiveColor, PorterDuff.Mode.SRC_IN));
   mModelTitlePaint.setColor(mInactiveColor);
   postInvalidate();
 }

public float getCornersRadius() {
   return mCornersRadius;
 }

public void setCornersRadius(final float cornersRadius) {
   mCornersRadius = cornersRadius;
   postInvalidate();
 }

public float getBadgeMargin() {
   return mBadgeMargin;
 }

public float getBarHeight() {
   return mBounds.height();
 }

public OnTabBarSelectedIndexListener getOnTabBarSelectedIndexListener() {
   return mOnTabBarSelectedIndexListener;
 }

// Set on tab bar selected index listener where you can trigger action onStart or onEnd
 public void setOnTabBarSelectedIndexListener(final OnTabBarSelectedIndexListener onTabBarSelectedIndexListener) {
   mOnTabBarSelectedIndexListener = onTabBarSelectedIndexListener;

if (mAnimatorListener == null)
     mAnimatorListener = new Animator.AnimatorListener() {
       @Override
       public void onAnimationStart(final Animator animation) {
         if (mOnTabBarSelectedIndexListener != null)
           mOnTabBarSelectedIndexListener.onStartTabSelected(mModels.get(mIndex), mIndex);
       }

@Override
       public void onAnimationEnd(final Animator animation) {
         if (mOnTabBarSelectedIndexListener != null)
           mOnTabBarSelectedIndexListener.onEndTabSelected(mModels.get(mIndex), mIndex);
       }

@Override
       public void onAnimationCancel(final Animator animation) {

}

@Override
       public void onAnimationRepeat(final Animator animation) {

}
     };
   mAnimator.removeListener(mAnimatorListener);
   mAnimator.addListener(mAnimatorListener);
 }

public void setViewPager(final ViewPager viewPager) {
   // Detect whether ViewPager mode
   if (viewPager == null) {
     mIsViewPagerMode = false;
     return;
   }

if (mViewPager == viewPager) return;
   if (mViewPager != null) mViewPager.setOnPageChangeListener(null);
   if (viewPager.getAdapter() == null)
     throw new IllegalStateException("ViewPager does not provide adapter instance.");

mIsViewPagerMode = true;
   mViewPager = viewPager;
   mViewPager.addOnPageChangeListener(this);

resetScroller();
   postInvalidate();
 }

public void setViewPager(final ViewPager viewPager, int index) {
   setViewPager(viewPager);

mIndex = index;
   if (mIsViewPagerMode) mViewPager.setCurrentItem(index, true);
   postInvalidate();
 }

// Reset scroller and reset scroll duration equals to animation duration
 private void resetScroller() {
   if (mViewPager == null) return;
   try {
     final Field scrollerField = ViewPager.class.getDeclaredField("mScroller");
     scrollerField.setAccessible(true);
     final ResizeViewPagerScroller scroller = new ResizeViewPagerScroller(getContext());
     scrollerField.set(mViewPager, scroller);
   } catch (Exception e) {
     e.printStackTrace();
   }
 }

public void setOnPageChangeListener(final ViewPager.OnPageChangeListener listener) {
   mOnPageChangeListener = listener;
 }

public int getModelIndex() {
   return mIndex;
 }

public void setModelIndex(int index) {
   setModelIndex(index, false);
 }

// Set model index from touch or programmatically
 public void setModelIndex(int index, boolean force) {
   if (mAnimator.isRunning()) return;
   if (mModels.isEmpty()) return;

// This check gives us opportunity to have an non selected model
   if (mIndex == INVALID_INDEX) force = true;

// Detect if last is the same
   if (index == mIndex) return;

// Snap index to models size
   index = Math.max(0, Math.min(index, mModels.size() - 1));

mIsResizeIn = index < mIndex;
   mLastIndex = mIndex;
   mIndex = index;

mIsSetIndexFromTabBar = true;
   if (mIsViewPagerMode) {
     if (mViewPager == null) throw new IllegalStateException("ViewPager is null.");
     mViewPager.setCurrentItem(index, true);
   }

// Set startX and endX for animation, where we animate two sides of rect with different interpolation
   mStartPointerX = mPointerLeftTop;
   mEndPointerX = mIndex * mModelSize;

// If it force, so update immediately, else animate
   // This happens if we set index onCreate or something like this
   // You can use force param or call this method in some post()
   if (force) updateIndicatorPosition(MAX_FRACTION);
   else mAnimator.start();
 }

private void updateIndicatorPosition(final float fraction) {
   // Update general fraction
   mFraction = fraction;

// Set the pointer left top side coordinate
   mPointerLeftTop =
       mStartPointerX + (mResizeInterpolator.getResizeInterpolation(fraction, mIsResizeIn) *
           (mEndPointerX - mStartPointerX));
   // Set the pointer right bottom side coordinate
   mPointerRightBottom =
       (mStartPointerX + mModelSize) +
           (mResizeInterpolator.getResizeInterpolation(fraction, !mIsResizeIn) *
               (mEndPointerX - mStartPointerX));

// Update pointer
   postInvalidate();
 }

// Update NTP
 private void notifyDataSetChanged() {
   postInvalidate();
 }

@Override
 public boolean onTouchEvent(final MotionEvent event) {
   // Return if animation is running
   if (mAnimator.isRunning()) return true;
   // If is not idle state, return
   if (mScrollState != ViewPager.SCROLL_STATE_IDLE) return true;

switch (event.getAction()) {
     case MotionEvent.ACTION_DOWN:
       // Action down touch
       mIsActionDown = true;
       if (!mIsViewPagerMode) break;
       // Detect if we touch down on pointer, later to move
       if (mIsHorizontalOrientation)
         mIsPointerActionDown = (int) (event.getX() / mModelSize) == mIndex;
       else
         mIsPointerActionDown = (int) (event.getY() / mModelSize) == mIndex;
       break;
     case MotionEvent.ACTION_MOVE:
       // If pointer touched, so move
       if (mIsPointerActionDown) {
         if (mIsHorizontalOrientation)
           mViewPager.setCurrentItem((int) (event.getX() / mModelSize), true);
         else
           mViewPager.setCurrentItem((int) (event.getY() / mModelSize), true);
         break;
       }
       if (mIsActionDown) break;
     case MotionEvent.ACTION_UP:
       // Press up and set model index relative to current coordinate
       if (mIsActionDown) {
         if (mIsHorizontalOrientation) setModelIndex((int) (event.getX() / mModelSize));
         else setModelIndex((int) (event.getY() / mModelSize));
       }
     case MotionEvent.ACTION_CANCEL:
     case MotionEvent.ACTION_OUTSIDE:
     default:
       // Reset action touch variables
       mIsPointerActionDown = false;
       mIsActionDown = false;
       break;
   }

return true;
 }

@Override
 protected void onMeasure(final int widthMeasureSpec, final int heightMeasureSpec) {
   super.onMeasure(widthMeasureSpec, heightMeasureSpec);

// Get measure size
   final int width = MeasureSpec.getSize(widthMeasureSpec);
   final int height = MeasureSpec.getSize(heightMeasureSpec);

if (mModels.isEmpty() || width == 0 || height == 0) return;

// Detect orientation and calculate icon size
   if (width > height) {
     mIsHorizontalOrientation = true;

// Get smaller side
     float side = mModelSize > height ? height : mModelSize;
     if (mIsBadged) side -= side * TITLE_SIZE_FRACTION;

mModelSize = (float) width / (float) mModels.size();
     mIconSize = (int) (side * (mIsTitled ? TITLE_ICON_SIZE_FRACTION : ICON_SIZE_FRACTION));

mModelTitleSize = side * TITLE_SIZE_FRACTION;
     mTitleMargin = side * TITLE_MARGIN_FRACTION;

// If is badged mode, so get vars and set paint with default bounds
     if (mIsBadged) {
       mBadgeTitleSize = mModelTitleSize * BADGE_TITLE_SIZE_FRACTION;

final Rect badgeBounds = new Rect();
       mBadgePaint.setTextSize(mBadgeTitleSize);
       mBadgePaint.getTextBounds(PREVIEW_BADGE, 0, 1, badgeBounds);
       mBadgeMargin = (badgeBounds.height() * 0.5f) +
           (mBadgeTitleSize * BADGE_HORIZONTAL_FRACTION * BADGE_VERTICAL_FRACTION);
     }
   } else {
     mIsHorizontalOrientation = false;
     mIsTitled = false;
     mIsBadged = false;

mModelSize = (float) height / (float) mModels.size();
     mIconSize = (int) ((mModelSize > width ? width : mModelSize) * ICON_SIZE_FRACTION);
   }

// Set bounds for NTB
   mBounds.set(0.0f, 0.0f, width, height - mBadgeMargin);

// Set main bitmap
   mBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
   mCanvas = new Canvas(mBitmap);

// Set pointer canvas
   mPointerBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
   mPointerCanvas = new Canvas(mPointerBitmap);

// Set icons canvas
   mIconsBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
   mIconsCanvas = new Canvas(mIconsBitmap);

// Set scale fraction for icons
   for (Model model : mModels) {
     final float originalIconSize = model.mIcon.getWidth() > model.mIcon.getHeight() ?
         model.mIcon.getWidth() : model.mIcon.getHeight();
     model.mInactiveIconScale = (float) mIconSize / originalIconSize;
     model.mActiveIconScaleBy = model.mInactiveIconScale *
         (mIsTitled ? TITLE_ACTIVE_ICON_SCALE_BY : ACTIVE_ICON_SCALE_BY);
   }

// Set start position of pointer for preview or on start
   if (isInEditMode() || !mIsViewPagerMode) {
     mIsSetIndexFromTabBar = true;

// Set random in preview mode
     if (isInEditMode()) {
       mIndex = new Random().nextInt(mModels.size());

if (mIsBadged)
         for (int i = 0; i < mModels.size(); i++) {
           final Model model = mModels.get(i);

if (i == mIndex) {
             model.mBadgeFraction = MAX_FRACTION;
             model.showBadge();
           } else {
             model.mBadgeFraction = MIN_FRACTION;
             model.hideBadge();
           }
         }
     }

mStartPointerX = mIndex * mModelSize;
     mEndPointerX = mStartPointerX;
     updateIndicatorPosition(MAX_FRACTION);
   }
 }

@Override
 protected void onDraw(final Canvas canvas) {
   if (mCanvas == null || mPointerCanvas == null || mIconsCanvas == null) return;

// Reset and clear canvases
   mCanvas.drawColor(0, PorterDuff.Mode.CLEAR);
   mPointerCanvas.drawColor(0, PorterDuff.Mode.CLEAR);
   mIconsCanvas.drawColor(0, PorterDuff.Mode.CLEAR);

// Get pointer badge margin for gravity
   final float pointerBadgeMargin = mBadgeGravity == BadgeGravity.TOP ? mBadgeMargin : 0.0f;

// Draw our model colors
   for (int i = 0; i < mModels.size(); i++) {
     mPaint.setColor(mModels.get(i).getColor());

if (mIsHorizontalOrientation) {
       final float left = mModelSize * i;
       final float right = left + mModelSize;
       mCanvas.drawRect(
           left, pointerBadgeMargin, right, mBounds.height() + pointerBadgeMargin, mPaint
       );
     } else {
       final float top = mModelSize * i;
       final float bottom = top + mModelSize;
       mCanvas.drawRect(0.0f, top, mBounds.width(), bottom, mPaint);
     }
   }

// Set bound of pointer
   if (mIsHorizontalOrientation)
     mPointerBounds.set(
         mPointerLeftTop, pointerBadgeMargin,
         mPointerRightBottom, mBounds.height() + pointerBadgeMargin
     );
   else mPointerBounds.set(0.0f, mPointerLeftTop, mBounds.width(), mPointerRightBottom);

// Draw pointer for model colors
   if (mCornersRadius == 0) mPointerCanvas.drawRect(mPointerBounds, mPaint);
   else mPointerCanvas.drawRoundRect(mPointerBounds, mCornersRadius, mCornersRadius, mPaint);

// Draw pointer into main canvas
   mCanvas.drawBitmap(mPointerBitmap, 0.0f, 0.0f, mPointerPaint);

// Draw model icons
   for (int i = 0; i < mModels.size(); i++) {
     final Model model = mModels.get(i);

// Variables to center our icons
     final float leftOffset;
     final float topOffset;
     final float matrixCenterX;
     final float matrixCenterY;

// Set vars for icon when model with title or without
     final float iconMarginTitleHeight = mIconSize + mTitleMargin + mModelTitleSize;
     final float leftTitleOffset = (mModelSize * i) + (mModelSize * 0.5f);
     final float topTitleOffset =
         mBounds.height() - (mBounds.height() - iconMarginTitleHeight) * 0.5f;

if (mIsHorizontalOrientation) {
       leftOffset = (mModelSize * i) + (mModelSize - model.mIcon.getWidth()) * 0.5f;
       topOffset = (mBounds.height() - model.mIcon.getHeight()) * 0.5f;

matrixCenterX = leftOffset + model.mIcon.getWidth() * 0.5f;
       matrixCenterY = topOffset + model.mIcon.getHeight() * 0.5f +
           (mIsTitled && mTitleMode == TitleMode.ALL ? mTitleMargin * 0.5f : 0.0f);
     } else {
       leftOffset = (mBounds.width() - model.mIcon.getWidth()) * 0.5f;
       topOffset = (mModelSize * i) + (mModelSize - model.mIcon.getHeight()) * 0.5f;

matrixCenterX = leftOffset + model.mIcon.getWidth() * 0.5f;
       matrixCenterY = topOffset + model.mIcon.getHeight() * 0.5f;
     }

// Title translate position
     final float titleTranslate = -model.mIcon.getHeight() + topTitleOffset - mTitleMargin * 0.5f;

// Translate icon to model center
     model.mIconMatrix.setTranslate(
         leftOffset,
         (mIsTitled && mTitleMode == TitleMode.ALL) ? titleTranslate : topOffset
     );

// Get interpolated fraction for left last and current models
     final float interpolation = mResizeInterpolator.getResizeInterpolation(mFraction, true);
     final float lastInterpolation = mResizeInterpolator.getResizeInterpolation(mFraction, false);
//      final float interpolation =
//          mIsScaled ? mResizeInterpolator.getResizeInterpolation(mFraction, true);
//      final float lastInterpolation =
//          mIsScaled ? mResizeInterpolator.getResizeInterpolation(mFraction, false) :
//              (MAX_FRACTION - NON_SCALED_FRACTION);

// Scale value relative to interpolation
     final float matrixScale = model.mActiveIconScaleBy *
         (mIsScaled ? interpolation : NON_SCALED_FRACTION);
     final float matrixLastScale = model.mActiveIconScaleBy *
         (mIsScaled ? lastInterpolation : (MAX_FRACTION - NON_SCALED_FRACTION));

// Get title alpha relative to interpolation
     final int titleAlpha = (int) (MAX_ALPHA * interpolation);
     final int titleLastAlpha = MAX_ALPHA - (int) (MAX_ALPHA * lastInterpolation);
     // Get title scale relative to interpolation
     final float titleScale = MAX_FRACTION +
         ((mIsScaled ? interpolation : NON_SCALED_FRACTION) * TITLE_ACTIVE_SCALE_BY);
     final float titleLastScale = mIsScaled ? (MAX_FRACTION + TITLE_ACTIVE_SCALE_BY) -
         (lastInterpolation * TITLE_ACTIVE_SCALE_BY) : titleScale;

// Check if we handle models from touch on NTP or from ViewPager
     // There is a strange logic of ViewPager onPageScrolled method, so it is
     if (mIsSetIndexFromTabBar) {
       if (mIndex == i)
         updateCurrentModel(
             model, leftOffset, topOffset, titleTranslate, interpolation,
             matrixCenterX, matrixCenterY, matrixScale, titleScale, titleAlpha
         );
       else if (mLastIndex == i)
         updateLastModel(
             model, leftOffset, topOffset, titleTranslate, lastInterpolation,
             matrixCenterX, matrixCenterY, matrixLastScale, titleLastScale, titleLastAlpha
         );
       else
         updateInactiveModel(
             model, leftOffset, topOffset, titleScale,
             matrixScale, matrixCenterX, matrixCenterY
         );
     } else {
       if (i != mIndex && i != mIndex + 1)
         updateInactiveModel(
             model, leftOffset, topOffset, titleScale,
             matrixScale, matrixCenterX, matrixCenterY
         );
       else if (i == mIndex + 1)
         updateCurrentModel(
             model, leftOffset, topOffset, titleTranslate, interpolation,
             matrixCenterX, matrixCenterY, matrixScale, titleScale, titleAlpha
         );
       else if (i == mIndex)
         updateLastModel(
             model, leftOffset, topOffset, titleTranslate, lastInterpolation,
             matrixCenterX, matrixCenterY, matrixLastScale, titleLastScale, titleLastAlpha
         );
     }

// Draw model icon
     mIconsCanvas.drawBitmap(model.mIcon, model.mIconMatrix, mIconPaint);
     if (mIsTitled)
       mIconsCanvas.drawText(
           isInEditMode() ? PREVIEW_TITLE : model.getTitle(),
           leftTitleOffset, topTitleOffset, mModelTitlePaint
       );
   }

// Draw pointer with active color to wrap out active icon
   if (mCornersRadius == 0) mIconsCanvas.drawRect(mPointerBounds, mIconPointerPaint);
   else
     mIconsCanvas.drawRoundRect(mPointerBounds, mCornersRadius, mCornersRadius, mIconPointerPaint);

// Draw general bitmap
   canvas.drawBitmap(mBitmap, 0.0f, 0.0f, null);
   // Draw icons bitmap on top
   canvas.drawBitmap(mIconsBitmap, 0.0f, pointerBadgeMargin, null);

// If is not badged, exit
   if (!mIsBadged) return;

// Model badge margin and offset relative to gravity mode
   final float modelBadgeMargin =
       mBadgeGravity == BadgeGravity.TOP ? mBadgeMargin : mBounds.height();
   final float modelBadgeOffset =
       mBadgeGravity == BadgeGravity.TOP ? 0.0f : mBounds.height() - mBadgeMargin;

for (int i = 0; i < mModels.size(); i++) {
     final Model model = mModels.get(i);

// Set preview badge title
     if (isInEditMode() || TextUtils.isEmpty(model.getBadgeTitle()))
       model.setBadgeTitle(PREVIEW_BADGE);

// Set badge title bounds
     mBadgePaint.setTextSize(mBadgeTitleSize * model.mBadgeFraction);
     mBadgePaint.getTextBounds(
         model.getBadgeTitle(), 0, model.getBadgeTitle().length(), mBadgeBounds
     );

// Get horizontal and vertical padding for bg
     final float horizontalPadding = mBadgeTitleSize * BADGE_HORIZONTAL_FRACTION;
     final float verticalPadding = horizontalPadding * BADGE_VERTICAL_FRACTION;

// Set horizontal badge offset
     final float badgeBoundsHorizontalOffset =
         (mModelSize * i) + (mModelSize * mBadgePosition.mPositionFraction);

// If is badge title only one char, so create circle else round rect
     if (model.getBadgeTitle().length() == 1) {
       final float badgeMargin = mBadgeMargin * model.mBadgeFraction;
       mBgBadgeBounds.set(
           badgeBoundsHorizontalOffset - badgeMargin, modelBadgeMargin - badgeMargin,
           badgeBoundsHorizontalOffset + badgeMargin, modelBadgeMargin + badgeMargin
       );
     } else
       mBgBadgeBounds.set(
           badgeBoundsHorizontalOffset - mBadgeBounds.centerX() - horizontalPadding,
           modelBadgeMargin - (mBadgeMargin * model.mBadgeFraction),
           badgeBoundsHorizontalOffset + mBadgeBounds.centerX() + horizontalPadding,
           modelBadgeOffset + (verticalPadding * 2.0f) + mBadgeBounds.height()
       );

// Set color and alpha for badge bg
     if (model.mBadgeFraction == MIN_FRACTION) mBadgePaint.setColor(Color.TRANSPARENT);
     else mBadgePaint.setColor(mActiveColor);
     mBadgePaint.setAlpha((int) (MAX_ALPHA * model.mBadgeFraction));

// Set corners to round rect for badge bg and draw
     final float cornerRadius = mBgBadgeBounds.height() * 0.5f;
     canvas.drawRoundRect(mBgBadgeBounds, cornerRadius, cornerRadius, mBadgePaint);

// Set color and alpha for badge title
     if (model.mBadgeFraction == MIN_FRACTION) mBadgePaint.setColor(Color.TRANSPARENT);
     else mBadgePaint.setColor(model.getColor());
     mBadgePaint.setAlpha((int) (MAX_ALPHA * model.mBadgeFraction));

// Set badge title center position and draw title
     final float badgeHalfHeight = mBadgeBounds.height() * 0.5f;
     float badgeVerticalOffset = (mBgBadgeBounds.height() * 0.5f) + badgeHalfHeight -
         mBadgeBounds.bottom + modelBadgeOffset;
     canvas.drawText(
         model.getBadgeTitle(), badgeBoundsHorizontalOffset, badgeVerticalOffset +
             mBadgeBounds.height() - (mBadgeBounds.height() * model.mBadgeFraction),
         mBadgePaint
     );
   }
 }

// Method to transform current fraction of NTB and position
 private void updateCurrentModel(
     final Model model,
     final float leftOffset,
     final float topOffset,
     final float titleTranslate,
     final float interpolation,
     final float matrixCenterX,
     final float matrixCenterY,
     final float matrixScale,
     final float textScale,
     final int textAlpha
 ) {
   if (mIsTitled && mTitleMode == TitleMode.ACTIVE)
     model.mIconMatrix.setTranslate(
         leftOffset, topOffset - (interpolation * (topOffset - titleTranslate))
     );

model.mIconMatrix.postScale(
       model.mInactiveIconScale + matrixScale, model.mInactiveIconScale + matrixScale,
       matrixCenterX, matrixCenterY + (mIsTitled && mTitleMode == TitleMode.ACTIVE ?
           mTitleMargin * 0.5f * interpolation : 0.0f)
   );

mModelTitlePaint.setTextSize(mModelTitleSize * textScale);
   if (mTitleMode == TitleMode.ACTIVE) mModelTitlePaint.setAlpha(textAlpha);
 }

// Method to transform last fraction of NTB and position
 private void updateLastModel(
     final Model model,
     final float leftOffset,
     final float topOffset,
     final float titleTranslate,
     final float lastInterpolation,
     final float matrixCenterX,
     final float matrixCenterY,
     final float matrixLastScale,
     final float textLastScale,
     final int textLastAlpha
 ) {
   if (mIsTitled && mTitleMode == TitleMode.ACTIVE)
     model.mIconMatrix.setTranslate(
         leftOffset, titleTranslate + (lastInterpolation * (topOffset - titleTranslate))
     );

model.mIconMatrix.postScale(
       model.mInactiveIconScale + model.mActiveIconScaleBy - matrixLastScale,
       model.mInactiveIconScale + model.mActiveIconScaleBy - matrixLastScale,
       matrixCenterX, matrixCenterY + (mIsTitled && mTitleMode == TitleMode.ACTIVE ?
           mTitleMargin * 0.5f - (mTitleMargin * 0.5f * lastInterpolation) : 0.0f)
   );

mModelTitlePaint.setTextSize(mModelTitleSize * textLastScale);
   if (mTitleMode == TitleMode.ACTIVE) mModelTitlePaint.setAlpha(textLastAlpha);
 }

// Method to transform others fraction of NTB and position
 private void updateInactiveModel(
     final Model model,
     final float leftOffset,
     final float topOffset,
     final float textScale,
     final float matrixScale,
     final float matrixCenterX,
     final float matrixCenterY
 ) {
   if (mIsTitled && mTitleMode == TitleMode.ACTIVE)
     model.mIconMatrix.setTranslate(leftOffset, topOffset);

if (mIsScaled)
     model.mIconMatrix.postScale(
         model.mInactiveIconScale, model.mInactiveIconScale, matrixCenterX, matrixCenterY
     );
   else
     model.mIconMatrix.postScale(
         model.mInactiveIconScale + matrixScale, model.mInactiveIconScale + matrixScale,
         matrixCenterX, matrixCenterY
     );

mModelTitlePaint.setTextSize(mModelTitleSize * (mIsScaled ? 1.0f : textScale));
   if (mTitleMode == TitleMode.ACTIVE) mModelTitlePaint.setAlpha(MIN_ALPHA);
 }

@Override
 public void onPageScrolled(int position, float positionOffset, final int positionOffsetPixels) {
   // If we animate, don`t call this
   if (!mIsSetIndexFromTabBar) {
     mIsResizeIn = position < mIndex;
     mLastIndex = mIndex;
     mIndex = position;

mStartPointerX = position * mModelSize;
     mEndPointerX = mStartPointerX + mModelSize;
     updateIndicatorPosition(positionOffset);
   }

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

@Override
 public void onPageSelected(final int position) {
   // If VP idle, so update
   if (mScrollState == ViewPager.SCROLL_STATE_IDLE) {
     mIsResizeIn = position < mIndex;
     mLastIndex = mIndex;
     mIndex = position;
     postInvalidate();
   }
 }

@Override
 public void onPageScrollStateChanged(final int state) {
   // If VP idle, reset to MIN_FRACTION
   if (state == ViewPager.SCROLL_STATE_IDLE) {
     mFraction = MIN_FRACTION;
     mIsSetIndexFromTabBar = false;

if (mOnPageChangeListener != null) mOnPageChangeListener.onPageSelected(mIndex);
     else {
       if (mOnTabBarSelectedIndexListener != null)
         mOnTabBarSelectedIndexListener.onEndTabSelected(mModels.get(mIndex), mIndex);
     }
   }
   mScrollState = state;

if (mOnPageChangeListener != null) mOnPageChangeListener.onPageScrollStateChanged(state);
 }

@Override
 public void onRestoreInstanceState(Parcelable state) {
   final SavedState savedState = (SavedState) state;
   super.onRestoreInstanceState(savedState.getSuperState());
   mIndex = savedState.index;
   requestLayout();
 }

@Override
 public Parcelable onSaveInstanceState() {
   final Parcelable superState = super.onSaveInstanceState();
   final SavedState savedState = new SavedState(superState);
   savedState.index = mIndex;
   return savedState;
 }

private static class SavedState extends BaseSavedState {
   int index;

public SavedState(Parcelable superState) {
     super(superState);
   }

private SavedState(Parcel in) {
     super(in);
     index = in.readInt();
   }

@Override
   public void writeToParcel(Parcel dest, int flags) {
     super.writeToParcel(dest, flags);
     dest.writeInt(index);
   }

@SuppressWarnings("UnusedDeclaration")
   public static final Creator<SavedState> CREATOR = new Creator<SavedState>() {
     @Override
     public SavedState createFromParcel(Parcel in) {
       return new SavedState(in);
     }

@Override
     public SavedState[] newArray(int size) {
       return new SavedState[size];
     }
   };
 }

@Override
 protected void onConfigurationChanged(final Configuration newConfig) {
   // Config view on rotate etc.
   super.onConfigurationChanged(newConfig);
   requestLayout();

// Refresh pointer and state after config changed to current
   final int tempIndex = mIndex;
   setModelIndex(INVALID_INDEX, true);
   post(new Runnable() {
     @Override
     public void run() {
       setModelIndex(tempIndex, true);
     }
   });
 }

// Model class
 public static class Model {

private String mTitle = "";
   private int mColor;

private Bitmap mIcon;
   private final Matrix mIconMatrix = new Matrix();

private String mBadgeTitle = "";
   private String mTempBadgeTitle = "";
   private float mBadgeFraction;

private boolean mIsBadgeShowed;
   private boolean mIsBadgeUpdated;

private final ValueAnimator mBadgeAnimator = new ValueAnimator();

private float mInactiveIconScale;
   private float mActiveIconScaleBy;

public Model(final Drawable icon, final int color) {
     mColor = color;
     if (icon != null) {
       if (icon instanceof BitmapDrawable) mIcon = ((BitmapDrawable) icon).getBitmap();
       else {
         mIcon = Bitmap.createBitmap(
             icon.getIntrinsicWidth(),
             icon.getIntrinsicHeight(),
             Bitmap.Config.ARGB_8888
         );
         final Canvas canvas = new Canvas(mIcon);
         icon.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
         icon.draw(canvas);
       }
     } else {
       mIcon = Bitmap.createBitmap(1, 1, Bitmap.Config.RGB_565);
     }

mBadgeAnimator.addListener(new Animator.AnimatorListener() {

@Override
       public void onAnimationStart(final Animator animation) {
       }

@Override
       public void onAnimationEnd(final Animator animation) {
         // Detect whether we just update text and don`t reset show state
         if (!mIsBadgeUpdated) mIsBadgeShowed = !mIsBadgeShowed;
         else mIsBadgeUpdated = false;
       }

@Override
       public void onAnimationCancel(final Animator animation) {

}

@Override
       public void onAnimationRepeat(final Animator animation) {
         // Change title when we update and don`t see the title
         if (mIsBadgeUpdated) mBadgeTitle = mTempBadgeTitle;
       }
     });
   }

public Model(final Drawable icon, final int color, final String title) {
     this(icon, color);
     mTitle = title;
   }

public Model(final Drawable icon, final int color, final String title, final String badgeTitle) {
     this(icon, color, title);
     mBadgeTitle = badgeTitle;
   }

public String getTitle() {
     return mTitle;
   }

public void setTitle(final String title) {
     mTitle = title;
   }

public int getColor() {
     return mColor;
   }

public void setColor(final int color) {
     mColor = color;
   }

public boolean isBadgeShowed() {
     return mIsBadgeShowed;
   }

public String getBadgeTitle() {
     return mBadgeTitle;
   }

public void setBadgeTitle(final String badgeTitle) {
     mBadgeTitle = badgeTitle;
   }

// If your badge is visible on screen, so you can update title with animation
   public void updateBadgeTitle(final String badgeTitle) {
     if (!mIsBadgeShowed) return;
     if (mBadgeAnimator.isRunning()) mBadgeAnimator.end();

mTempBadgeTitle = badgeTitle;
     mIsBadgeUpdated = true;

mBadgeAnimator.setFloatValues(MAX_FRACTION, MIN_FRACTION);
     mBadgeAnimator.setDuration(DEFAULT_BADGE_REFRESH_ANIMATION_DURATION);
     mBadgeAnimator.setRepeatMode(ValueAnimator.REVERSE);
     mBadgeAnimator.setRepeatCount(1);
     mBadgeAnimator.start();
   }

public void toggleBadge() {
     if (mBadgeAnimator.isRunning()) mBadgeAnimator.end();
     if (mIsBadgeShowed) hideBadge();
     else showBadge();
   }

public void showBadge() {
     mIsBadgeUpdated = false;

if (mBadgeAnimator.isRunning()) mBadgeAnimator.end();
     if (mIsBadgeShowed) return;

mBadgeAnimator.setFloatValues(MIN_FRACTION, MAX_FRACTION);
     mBadgeAnimator.setInterpolator(DECELERATE_INTERPOLATOR);
     mBadgeAnimator.setDuration(DEFAULT_BADGE_ANIMATION_DURATION);
     mBadgeAnimator.setRepeatMode(ValueAnimator.RESTART);
     mBadgeAnimator.setRepeatCount(0);
     mBadgeAnimator.start();
   }

public void hideBadge() {
     mIsBadgeUpdated = false;

if (mBadgeAnimator.isRunning()) mBadgeAnimator.end();
     if (!mIsBadgeShowed) return;

mBadgeAnimator.setFloatValues(MAX_FRACTION, MIN_FRACTION);
     mBadgeAnimator.setInterpolator(ACCELERATE_INTERPOLATOR);
     mBadgeAnimator.setDuration(DEFAULT_BADGE_ANIMATION_DURATION);
     mBadgeAnimator.setRepeatMode(ValueAnimator.RESTART);
     mBadgeAnimator.setRepeatCount(0);
     mBadgeAnimator.start();
   }
 }

// Custom scroller with custom scroll duration
 private class ResizeViewPagerScroller extends Scroller {

public ResizeViewPagerScroller(Context context) {
     super(context, new AccelerateDecelerateInterpolator());
   }

@Override
   public void startScroll(int startX, int startY, int dx, int dy, int duration) {
     super.startScroll(startX, startY, dx, dy, mAnimationDuration);
   }

@Override
   public void startScroll(int startX, int startY, int dx, int dy) {
     super.startScroll(startX, startY, dx, dy, mAnimationDuration);
   }
 }

// Resize interpolator to create smooth effect on pointer according to inspiration design
 // This is like improved accelerated and decelerated interpolator
 private class ResizeInterpolator implements Interpolator {

// Spring factor
   private final float mFactor = 1.0f;
   // Check whether side we move
   private boolean mResizeIn;

@Override
   public float getInterpolation(final float input) {
     if (mResizeIn) return (float) (1.0f - Math.pow((1.0f - input), 2.0f * mFactor));
     else return (float) (Math.pow(input, 2.0f * mFactor));
   }

public float getResizeInterpolation(final float input, final boolean resizeIn) {
     mResizeIn = resizeIn;
     return getInterpolation(input);
   }
 }

// Model title mode
 public enum TitleMode {
   ALL, ACTIVE
 }

// Model badge position
 public enum BadgePosition {

LEFT(LEFT_FRACTION), CENTER(CENTER_FRACTION), RIGHT(RIGHT_FRACTION);

private float mPositionFraction;

BadgePosition() {
     mPositionFraction = RIGHT_FRACTION;
   }

BadgePosition(final float positionFraction) {
     mPositionFraction = positionFraction;
   }
 }

// Model badge gravity
 public enum BadgeGravity {
   TOP, BOTTOM
 }

// Out listener for selected index
 public interface OnTabBarSelectedIndexListener {
   void onStartTabSelected(final Model model, final int index);

void onEndTabSelected(final Model model, final int index);
 }
}

布局：

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
 xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:app="http://schemas.android.com/apk/res-auto"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:orientation="vertical">

<android.support.v4.view.ViewPager
   android:id="@+id/vp_horizontal_ntb"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:layout_above="@+id/wrapper_ntb_horizontal"/>

<FrameLayout
   android:id="@+id/wrapper_ntb_horizontal"
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:layout_alignParentBottom="true">

<View
     android:id="@+id/bg_ntb_horizontal"
     android:layout_width="match_parent"
     android:layout_height="52dp"
     android:layout_gravity="bottom"
     android:background="#605271"/>

<com.bzu.gxs.meunguide.NavigationTabBar
     android:id="@+id/ntb_horizontal"
     android:layout_width="match_parent"
     android:layout_height="60dp"
     android:layout_gravity="center"
     android:background="@drawable/bg_round_circle"
     app:ntb_animation_duration="400"
     app:ntb_preview_colors="@array/red_wine"
     app:ntb_corners_radius="50dp"
     app:ntb_scaled="false"
     app:ntb_active_color="#8d88e4"
     app:ntb_inactive_color="#dddfec"/>

</FrameLayout>

</RelativeLayout>

activity_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:orientation="vertical"
 android:weightSum="4">

<TextView
   android:id="@+id/txt_vp_item_page"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:layout_margin="10dp"
   android:background="@drawable/bg_round_rect"
   android:gravity="center"
   android:text="Page"
   android:textColor="#9b92b3"
   android:textStyle="bold"/>

</LinearLayout>