最近工作较忙，勿发私信，最近看了一篇不错的博客（http://blog.csdn.net/t12x3456/article/details/13290349），使用第三方插件实现京东广告Banner，3D旋转的ViewPager，虽然博主只是讲解了一些简单的nineoldandroids，但是对nineoldandroids这个控件产生了浓厚的兴趣，于是又看了大神任玉刚的详解nineoldandroids（http://blog.csdn.net/singwhatiwanna/article/details/17639987），发现这个第三方控件实在牛逼，于是打算尝试下。还是先上图：
通过反编译京东的apk，看了一遍，京东是如何实现的这个3D旋转动画ViewPager。首先定义布局文件如下：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true"
android:orientation="vertical"
tools:context=".MainActivity" >
<com.aimn.dviewpager.JazzyViewPager
android:id="@+id/index_product_images_container"
android:layout_width="match_parent"
android:layout_height="125dp"
android:background="@color/white" >
</com.aimn.dviewpager.JazzyViewPager>
<LinearLayout
android:id="@+id/index_product_images_indicator"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/white"
android:orientation="horizontal" />
</LinearLayout>
布局很简单，自定义了一个名为JazzyViewPager的控件，还有一个LinearLayout。
红色部分就是JazzyViewPager，而下面那个类似于RadioButton的就是LinearLayout。
然后就是去自定义JazzyViewPager，这个JazzyViewPager肯定继承了ViewPager，我把介绍写在注释里面了，大家可以看代码：
public class JazzyViewPager extends ViewPager {
public static final String TAG = "JazzyViewPager";
private boolean mEnabled = true;
private boolean mFadeEnabled = false;
private boolean mOutlineEnabled = false;
public static int sOutlineColor = Color.WHITE;
private TransitionEffect mEffect = TransitionEffect.Standard;
private HashMap<Integer, Object> mObjs = new LinkedHashMap<Integer, Object>();
private static final float SCALE_MAX = 0.5f;
private static final float ZOOM_MAX = 0.5f;
private static final float ROT_MAX = 15.0f;
public enum TransitionEffect {
Standard, Tablet, CubeIn, CubeOut, FlipVertical, FlipHorizontal, Stack, ZoomIn, ZoomOut, RotateUp, RotateDown, Accordion
}
public JazzyViewPager(Context context) {
this(context, null);
}
// 构造器，构造器就是干了几个事情，一、定义了一个TypedArray，这是什么大家可以百度自定属性，绑定自定义的
// 属性和特效
@SuppressWarnings("incomplete-switch")
public JazzyViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
setClipChildren(false);
TypedArray ta = context.obtainStyledAttributes(attrs,
R.styleable.JazzyViewPager);
int effect = ta.getInt(R.styleable.JazzyViewPager_style, 0);
String[] transitions = getResources().getStringArray(
R.array.jazzy_effects);
setTransitionEffect(TransitionEffect.valueOf(transitions[effect]));
setFadeEnabled(ta.getBoolean(R.styleable.JazzyViewPager_fadeEnabled,
false));
setOutlineEnabled(ta.getBoolean(
R.styleable.JazzyViewPager_outlineEnabled, false));
setOutlineColor(ta.getColor(R.styleable.JazzyViewPager_outlineColor,
Color.WHITE));
switch (mEffect) {
case Stack:
case ZoomOut:
setFadeEnabled(true);
}
ta.recycle();
}
public void setTransitionEffect(TransitionEffect effect) {
mEffect = effect;
}
public void setPagingEnabled(boolean enabled) {
mEnabled = enabled;
}
public void setFadeEnabled(boolean enabled) {
mFadeEnabled = enabled;
}
public boolean getFadeEnabled() {
return mFadeEnabled;
}
public void setOutlineEnabled(boolean enabled) {
mOutlineEnabled = enabled;
wrapWithOutlines();
}
public void setOutlineColor(int color) {
sOutlineColor = color;
}
private void wrapWithOutlines() {
for (int i = 0; i < getChildCount(); i++) {
View v = getChildAt(i);
if (!(v instanceof OutlineContainer)) {
removeView(v);
super.addView(wrapChild(v), i);
}
}
}
private View wrapChild(View child) {
if (!mOutlineEnabled || child instanceof OutlineContainer)
return child;
OutlineContainer out = new OutlineContainer(getContext());
out.setLayoutParams(generateDefaultLayoutParams());
child.setLayoutParams(new OutlineContainer.LayoutParams(
LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
out.addView(child);
return out;
}
public void addView(View child) {
super.addView(wrapChild(child));
}
public void addView(View child, int index) {
super.addView(wrapChild(child), index);
}
public void addView(View child, LayoutParams params) {
super.addView(wrapChild(child), params);
}
public void addView(View child, int width, int height) {
super.addView(wrapChild(child), width, height);
}
public void addView(View child, int index, LayoutParams params) {
super.addView(wrapChild(child), index, params);
}
@Override
public boolean onInterceptTouchEvent(MotionEvent arg0) {
return mEnabled ? super.onInterceptTouchEvent(arg0) : false;
}
private State mState;
private int oldPage;
private View mLeft;
private View mRight;
private float mRot;
private float mTrans;
private float mScale;
private enum State {
IDLE, GOING_LEFT, GOING_RIGHT
}
private void logState(View v, String title) {
Log.v(TAG,
title + ": ROT (" + ViewHelper.getRotation(v) + ", "
+ ViewHelper.getRotationX(v) + ", "
+ ViewHelper.getRotationY(v) + "), TRANS ("
+ ViewHelper.getTranslationX(v) + ", "
+ ViewHelper.getTranslationY(v) + "), SCALE ("
+ ViewHelper.getScaleX(v) + ", "
+ ViewHelper.getScaleY(v) + "), ALPHA "
+ ViewHelper.getAlpha(v));
}
protected void animateScroll(int position, float positionOffset) {
if (mState != State.IDLE) {
mRot = (float) (1 - Math.cos(2 * Math.PI * positionOffset)) / 2 * 30.0f;
ViewHelper.setRotationY(this, mState == State.GOING_RIGHT ? mRot
: -mRot);
ViewHelper.setPivotX(this, getMeasuredWidth() * 0.5f);
ViewHelper.setPivotY(this, getMeasuredHeight() * 0.5f);
}
}
protected void animateTablet(View left, View right, float positionOffset) {
if (mState != State.IDLE) {
if (left != null) {
mRot = 30.0f * positionOffset;
mTrans = getOffsetXForRotation(mRot, left.getMeasuredWidth(),
left.getMeasuredHeight());
ViewHelper.setPivotX(left, left.getMeasuredWidth() / 2);
ViewHelper.setPivotY(left, left.getMeasuredHeight() / 2);
ViewHelper.setTranslationX(left, mTrans);
ViewHelper.setRotationY(left, mRot);
logState(left, "Left");
}
if (right != null) {
mRot = -30.0f * (1 - positionOffset);
mTrans = getOffsetXForRotation(mRot, right.getMeasuredWidth(),
right.getMeasuredHeight());
ViewHelper.setPivotX(right, right.getMeasuredWidth() * 0.5f);
ViewHelper.setPivotY(right, right.getMeasuredHeight() * 0.5f);
ViewHelper.setTranslationX(right, mTrans);
ViewHelper.setRotationY(right, mRot);
logState(right, "Right");
}
}
}
private void animateCube(View left, View right, float positionOffset,
boolean in) {
if (mState != State.IDLE) {
if (left != null) {
mRot = (in ? 90.0f : -90.0f) * positionOffset;
ViewHelper.setPivotX(left, left.getMeasuredWidth());
ViewHelper.setPivotY(left, left.getMeasuredHeight() * 0.5f);
ViewHelper.setRotationY(left, mRot);
}
if (right != null) {
mRot = -(in ? 90.0f : -90.0f) * (1 - positionOffset);
ViewHelper.setPivotX(right, 0);
ViewHelper.setPivotY(right, right.getMeasuredHeight() * 0.5f);
ViewHelper.setRotationY(right, mRot);
}
}
}
private void animateAccordion(View left, View right, float positionOffset) {
if (mState != State.IDLE) {
if (left != null) {
ViewHelper.setPivotX(left, left.getMeasuredWidth());
ViewHelper.setPivotY(left, 0);
ViewHelper.setScaleX(left, 1 - positionOffset);
}
if (right != null) {
ViewHelper.setPivotX(right, 0);
ViewHelper.setPivotY(right, 0);
ViewHelper.setScaleX(right, positionOffset);
}
}
}
private void animateZoom(View left, View right, float positionOffset,
boolean in) {
if (mState != State.IDLE) {
if (left != null) {
mScale = in ? ZOOM_MAX + (1 - ZOOM_MAX) * (1 - positionOffset)
: 1 + ZOOM_MAX - ZOOM_MAX * (1 - positionOffset);
ViewHelper.setPivotX(left, left.getMeasuredWidth() * 0.5f);
ViewHelper.setPivotY(left, left.getMeasuredHeight() * 0.5f);
ViewHelper.setScaleX(left, mScale);
ViewHelper.setScaleY(left, mScale);
}
if (right != null) {
mScale = in ? ZOOM_MAX + (1 - ZOOM_MAX) * positionOffset : 1
+ ZOOM_MAX - ZOOM_MAX * positionOffset;
ViewHelper.setPivotX(right, right.getMeasuredWidth() * 0.5f);
ViewHelper.setPivotY(right, right.getMeasuredHeight() * 0.5f);
ViewHelper.setScaleX(right, mScale);
ViewHelper.setScaleY(right, mScale);
}
}
}
private void animateRotate(View left, View right, float positionOffset,
boolean up) {
if (mState != State.IDLE) {
if (left != null) {
mRot = (up ? 1 : -1) * (ROT_MAX * positionOffset);
mTrans = (up ? -1 : 1)
* (float) (getMeasuredHeight() - getMeasuredHeight()
* Math.cos(mRot * Math.PI / 180.0f));
ViewHelper.setPivotX(left, left.getMeasuredWidth() * 0.5f);
ViewHelper.setPivotY(left, up ? 0 : left.getMeasuredHeight());
ViewHelper.setTranslationY(left, mTrans);
ViewHelper.setRotation(left, mRot);
}
if (right != null) {
mRot = (up ? 1 : -1) * (-ROT_MAX + ROT_MAX * positionOffset);
mTrans = (up ? -1 : 1)
* (float) (getMeasuredHeight() - getMeasuredHeight()
* Math.cos(mRot * Math.PI / 180.0f));
ViewHelper.setPivotX(right, right.getMeasuredWidth() * 0.5f);
ViewHelper.setPivotY(right, up ? 0 : right.getMeasuredHeight());
ViewHelper.setTranslationY(right, mTrans);
ViewHelper.setRotation(right, mRot);
}
}
}
private void animateFlipHorizontal(View left, View right,
float positionOffset, int positionOffsetPixels) {
if (mState != State.IDLE) {
if (left != null) {
mRot = 180.0f * positionOffset;
if (mRot > 90.0f) {
left.setVisibility(View.INVISIBLE);
} else {
if (left.getVisibility() == View.INVISIBLE)
left.setVisibility(View.VISIBLE);
mTrans = positionOffsetPixels;
ViewHelper.setPivotX(left, left.getMeasuredWidth() * 0.5f);
ViewHelper.setPivotY(left, left.getMeasuredHeight() * 0.5f);
ViewHelper.setTranslationX(left, mTrans);
ViewHelper.setRotationY(left, mRot);
}
}
if (right != null) {
mRot = -180.0f * (1 - positionOffset);
if (mRot < -90.0f) {
right.setVisibility(View.INVISIBLE);
} else {
if (right.getVisibility() == View.INVISIBLE)
right.setVisibility(View.VISIBLE);
mTrans = -getWidth() - getPageMargin()
+ positionOffsetPixels;
ViewHelper
.setPivotX(right, right.getMeasuredWidth() * 0.5f);
ViewHelper.setPivotY(right,
right.getMeasuredHeight() * 0.5f);
ViewHelper.setTranslationX(right, mTrans);
ViewHelper.setRotationY(right, mRot);
}
}
}
}
private void animateFlipVertical(View left, View right,
float positionOffset, int positionOffsetPixels) {
if (mState != State.IDLE) {
if (left != null) {
mRot = 180.0f * positionOffset;
if (mRot > 90.0f) {
left.setVisibility(View.INVISIBLE);
} else {
if (left.getVisibility() == View.INVISIBLE)
left.setVisibility(View.VISIBLE);
mTrans = positionOffsetPixels;
ViewHelper.setPivotX(left, left.getMeasuredWidth() * 0.5f);
ViewHelper.setPivotY(left, left.getMeasuredHeight() * 0.5f);
ViewHelper.setTranslationX(left, mTrans);
ViewHelper.setRotationX(left, mRot);
}
}
if (right != null) {
mRot = -180.0f * (1 - positionOffset);
if (mRot < -90.0f) {
right.setVisibility(View.INVISIBLE);
} else {
if (right.getVisibility() == View.INVISIBLE)
right.setVisibility(View.VISIBLE);
mTrans = -getWidth() - getPageMargin()
+ positionOffsetPixels;
ViewHelper
.setPivotX(right, right.getMeasuredWidth() * 0.5f);
ViewHelper.setPivotY(right,
right.getMeasuredHeight() * 0.5f);
ViewHelper.setTranslationX(right, mTrans);
ViewHelper.setRotationX(right, mRot);
}
}
}
}
protected void animateStack(View left, View right, float positionOffset,
int positionOffsetPixels) {
if (mState != State.IDLE) {
if (right != null) {
mScale = (1 - SCALE_MAX) * positionOffset + SCALE_MAX;
mTrans = -getWidth() - getPageMargin() + positionOffsetPixels;
ViewHelper.setScaleX(right, mScale);
ViewHelper.setScaleY(right, mScale);
ViewHelper.setTranslationX(right, mTrans);
}
if (left != null) {
left.bringToFront();
}
}
}
private Matrix mMatrix = new Matrix();
private Camera mCamera = new Camera();
private float[] mTempFloat2 = new float[2];
protected float getOffsetXForRotation(float degrees, int width, int height) {
mMatrix.reset();
mCamera.save();
mCamera.rotateY(Math.abs(degrees));
mCamera.getMatrix(mMatrix);
mCamera.restore();
mMatrix.preTranslate(-width * 0.5f, -height * 0.5f);
mMatrix.postTranslate(width * 0.5f, height * 0.5f);
mTempFloat2[0] = width;
mTempFloat2[1] = height;
mMatrix.mapPoints(mTempFloat2);
return (width - mTempFloat2[0]) * (degrees > 0.0f ? 1.0f : -1.0f);
}
protected void animateFade(View left, View right, float positionOffset) {
if (left != null) {
ViewHelper.setAlpha(left, 1 - positionOffset);
}
if (right != null) {
ViewHelper.setAlpha(right, positionOffset);
}
}
protected void animateOutline(View left, View right) {
if (!(left instanceof OutlineContainer))
return;
if (mState != State.IDLE) {
if (left != null) {
((OutlineContainer) left).setOutlineAlpha(1.0f);
}
if (right != null) {
((OutlineContainer) right).setOutlineAlpha(1.0f);
}
} else {
if (left != null)
((OutlineContainer) left).start();
if (right != null)
((OutlineContainer) right).start();
}
}
@Override
public void onPageScrolled(int position, float positionOffset,
int positionOffsetPixels) {
if (mState == State.IDLE && positionOffset > 0) {
oldPage = getCurrentItem();
mState = position == oldPage ? State.GOING_RIGHT : State.GOING_LEFT;
}
boolean goingRight = position == oldPage;
if (mState == State.GOING_RIGHT && !goingRight)
mState = State.GOING_LEFT;
else if (mState == State.GOING_LEFT && goingRight)
mState = State.GOING_RIGHT;
float effectOffset = isSmall(positionOffset) ? 0 : positionOffset;
// mLeft = getChildAt(position);
// mRight = getChildAt(position+1);
mLeft = findViewFromObject(position);
mRight = findViewFromObject(position + 1);
if (mFadeEnabled)
animateFade(mLeft, mRight, effectOffset);
if (mOutlineEnabled)
animateOutline(mLeft, mRight);
switch (mEffect) {
case Standard:
break;
case Tablet:
animateTablet(mLeft, mRight, effectOffset);
break;
case CubeIn:
animateCube(mLeft, mRight, effectOffset, true);
break;
case CubeOut:
animateCube(mLeft, mRight, effectOffset, false);
break;
case FlipVertical:
animateFlipVertical(mLeft, mRight, positionOffset,
positionOffsetPixels);
break;
case FlipHorizontal:
animateFlipHorizontal(mLeft, mRight, effectOffset,
positionOffsetPixels);
case Stack:
animateStack(mLeft, mRight, effectOffset, positionOffsetPixels);
break;
case ZoomIn:
animateZoom(mLeft, mRight, effectOffset, true);
break;
case ZoomOut:
animateZoom(mLeft, mRight, effectOffset, false);
break;
case RotateUp:
animateRotate(mLeft, mRight, effectOffset, true);
break;
case RotateDown:
animateRotate(mLeft, mRight, effectOffset, false);
break;
case Accordion:
animateAccordion(mLeft, mRight, effectOffset);
break;
}
super.onPageScrolled(position, positionOffset, positionOffsetPixels);
if (effectOffset == 0) {
mState = State.IDLE;
}
}
private boolean isSmall(float positionOffset) {
return Math.abs(positionOffset) < 0.0001;
}
public void setObjectForPosition(Object obj, int position) {
mObjs.put(Integer.valueOf(position), obj);
}
public View findViewFromObject(int position) {
Object o = mObjs.get(Integer.valueOf(position));
if (o == null) {
return null;
}
PagerAdapter a = getAdapter();
View v;
for (int i = 0; i < getChildCount(); i++) {
v = getChildAt(i);
if (a.isViewFromObject(v, o))
return v;
}
return null;
}
}
代码中通过ViewHelper去画出了许多动画，而这个ViewHelper就是nineoldandroids第三方提供的，然后再复写viewpager的onPagerSocller方法去实现ViewPager在滑动或者替换的时候的动画效果。其中还有个OutlineContainer，其实我也没搞懂，为啥要通过这个外线容器去画，望大神指导下OutlineContainer的作用。
public class OutlineContainer extends FrameLayout implements Animatable {
private Paint mOutlinePaint;
private boolean mIsRunning = false;
private long mStartTime;
private float mAlpha = 1.0f;
private static final long ANIMATION_DURATION = 500;
private static final long FRAME_DURATION = 1000 / 60;
private final Interpolator mInterpolator = new Interpolator() {
public float getInterpolation(float t) {
t -= 1.0f;
return t * t * t + 1.0f;
}
};
public OutlineContainer(Context context) {
super(context);
init();
}
public OutlineContainer(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public OutlineContainer(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
}
private void init() {
mOutlinePaint = new Paint();
mOutlinePaint.setAntiAlias(true);
mOutlinePaint.setStrokeWidth(dpToPx(getResources(), 2));
mOutlinePaint.setColor(getResources().getColor(R.color.blue));
mOutlinePaint.setStyle(Style.STROKE);
int padding = dpToPx(getResources(), 10);
setPadding(padding, padding, padding, padding);
}
@Override
protected void dispatchDraw(Canvas canvas) {
super.dispatchDraw(canvas);
int offset = dpToPx(getResources(), 5);
if (mOutlinePaint.getColor() != JazzyViewPager.sOutlineColor) {
mOutlinePaint.setColor(JazzyViewPager.sOutlineColor);
}
mOutlinePaint.setAlpha((int) (mAlpha * 255));
Rect rect = new Rect(offset, offset, getMeasuredWidth() - offset,
getMeasuredHeight() - offset);
canvas.drawRect(rect, mOutlinePaint);
}
public void setOutlineAlpha(float alpha) {
mAlpha = alpha;
}
@Override
public boolean isRunning() {
return mIsRunning;
}
@Override
public void start() {
if (mIsRunning)
return;
mIsRunning = true;
mStartTime = AnimationUtils.currentAnimationTimeMillis();
post(mUpdater);
}
@Override
public void stop() {
if (!mIsRunning)
return;
mIsRunning = false;
}
private final Runnable mUpdater = new Runnable() {
@Override
public void run() {
long now = AnimationUtils.currentAnimationTimeMillis();
long duration = now - mStartTime;
if (duration >= ANIMATION_DURATION) {
mAlpha = 0.0f;
invalidate();
stop();
return;
} else {
mAlpha = mInterpolator.getInterpolation(1 - duration
/ (float) ANIMATION_DURATION);
invalidate();
}
postDelayed(mUpdater, FRAME_DURATION);
}
};
private int dpToPx(Resources res, int dp) {
return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp,
res.getDisplayMetrics());
}
}
定义完以后使用就很简单了，在MainActivtiy里面绑定JazzyViewPager的ID，然后初始化控件，在定义一个handler去定时旋转。
mViewPager=(JazzyViewPager) findViewById(R.id.index_product_images_container);
mViewPager.setTransitionEffect(TransitionEffect.CubeOut);
mViewPager.setCurrentItem(0);
mHandler.sendEmptyMessageDelayed(MSG_CHANGE_PHOTO, PHOTO_CHANGE_TIME);
mViewPager.setAdapter(new MyAdapter());
mViewPager.setOnPageChangeListener(new MyPageChangeListener());
mViewPager.setOnTouchListener(new OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
if (mImageUrls.size() == 0 || mImageUrls.size() == 1)
return true;
else
return false;
}
});
在MyAdapter里面去加载图片，京东的Banner就轻松实现了。