先看看效果图：

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 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

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 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 getModels() {

return mModels;

}

public void setModels(final List 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 CREATOR = new Creator() {

@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

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:id="@+id/vp_horizontal_ntb"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:layout_above="@+id/wrapper_ntb_horizontal"/>

android:id="@+id/wrapper_ntb_horizontal"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_alignParentBottom="true">

android:id="@+id/bg_ntb_horizontal"

android:layout_width="match_parent"

android:layout_height="52dp"

android:layout_gravity="bottom"

android:background="#605271"/>

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"/>

activity_item.xml

android:layout_width="match_parent"

android:layout_height="match_parent"

android:orientation="vertical"

android:weightSum="4">

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"/>

以上就是本文的全部内容，希望能给大家一个参考，也希望大家多多支持脚本之家。