@Override public void onCreate() {
	super.onCreate();
	// Initialize typeface helper
	TypefaceCollection typeface = new TypefaceCollection.Builder()
	        .set(Typeface.NORMAL, Typeface.createFromAsset(getAssets(), "fonts/ubuntu/Ubuntu-R.ttf"))
	        .create();
	TypefaceHelper.init(typeface);
}

@Override protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.activity_layout);
	TypefaceHelper.typeface(this);
}

public static void typeface(View view);

private static void applyForView(View view, TypefaceCollection typefaceCollection) {
   if (view instanceof TextView) {
      TextView textView = (TextView) view;
      Typeface oldTypeface = textView.getTypeface();
      final int style = oldTypeface == null ? Typeface.NORMAL : oldTypeface.getStyle();
      textView.setTypeface(typefaceCollection.getTypeface(style));
      textView.setPaintFlags(textView.getPaintFlags() | Paint.SUBPIXEL_TEXT_FLAG);
   }
}

public static SpannableString typeface(CharSequence sequence, TypefaceCollection typefaceCollection);

private static class TypefaceSpan extends MetricAffectingSpan {
   Typeface typeface;
  
   @Override public void updateDrawState(TextPaint tp) {
      tp.setTypeface(typeface);
      tp.setFlags(tp.getFlags() | Paint.SUBPIXEL_TEXT_FLAG);
   }
}

@Override
public void onCreate() {
    super.onCreate();
    CalligraphyConfig.initDefault(new CalligraphyConfig.Builder()
                            .setDefaultFontPath("fonts/Roboto-RobotoRegular.ttf")
                            .setFontAttrId(R.attr.fontPath)
                            .build()
            );

@Override
protected void attachBaseContext(Context newBase) {
    super.attachBaseContext(CalligraphyContextWrapper.wrap(newBase));
}

public View inflate(@LayoutRes int resource, ViewGroup root, boolean attachToRoot) {
    final Resources res = getContext().getResources();
    final XmlResourceParser parser = res.getLayout(resource); 
    AttributeSet attrs = Xml.asAttributeSet(parser);
  
    View result = root;
    View temp = createViewFromTag(root, name, inflaterContext, attrs);
    ViewGroup.LayoutParams params = root.generateLayoutParams(attrs);
    if (!attachToRoot) {
      temp.setLayoutParams(params);
    }
    
    if (root != null && attachToRoot) {
        root.addView(temp, params);
    }
    if (root == null || !attachToRoot) {
        result = temp;
    }
    return result;
}

View createViewFromTag(View parent, String name, Context context, AttributeSet attrs){
  TypedArray ta = context.obtainStyledAttributes(attrs, ATTRS_THEME);
  int themeResId = ta.getResourceId(0, 0);
  context = new ContextThemeWrapper(context, themeResId);
  
  View view;
  if (mFactory2 != null) {
      view = mFactory2.onCreateView(parent, name, context, attrs);
  } else if (mFactory != null) {
      view = mFactory.onCreateView(name, context, attrs);
  } else {
      view = null;
  }  
  if (view == null && mPrivateFactory != null) {
      view = mPrivateFactory.onCreateView(parent, name, context, attrs);
  }  
  
  if (view == null) {
      final Object lastContext = mConstructorArgs[0];
      mConstructorArgs[0] = context;
      if (-1 == name.indexOf('.')) {
          view = onCreateView(parent, name, attrs); //使用反射创建
      } else {
          view = createView(name, null, attrs);     //使用反射创建
      }
   }
   return view;
}

//Factory2 只能设置一次，所以先用反射修改 mFactorySet 的值，以解除此限制
LayoutInflater inflater = LayoutInflater.from(this);
Class cls = LayoutInflater.class;
Field bool = cls.getDeclaredField("mFactorySet");
bool.setAccessible(true);
bool.setBoolean(inflater, false);
inflater.setFactory2(new LayoutInflater.Factory2() {
      
   @Override
   public View onCreateView(View parent, String name, Context context, AttributeSet attrs) {
       if(name.equals("TextView")) {
           int count = attrs.getAttributeCount();
            for (int i = 0; i < count; i++) {
                Log.i(TAG, attrs.getAttributeName(i)); //customFont
                Log.i(TAG, attrs.getAttributeValue(i));//fonts/Rotobo-Bold.ttf
            }
            return null;
      }
});

public View onCreateView(View parent, String name, Context context, AttributeSet attrs) {
       if(name.equals("TextView")) {
             TextView textview = new TextView(MainActivity.this);
             textview.setLayoutParams(new ViewGroup.LayoutParams(400, 100));
             textview.setText("中华大道 English hello 123456");
             int count = attrs.getAttributeCount();
             for (int i = 0; i < count; i++) {
                 if(attrs.getAttributeName(i).equals("customfont")){
                      String path = attrs.getAttributeValue(i);
                      Typeface typeface = Typeface.createFromAsset(getAssets(), path);
                      textview.setTypeface(typeface);
                  }
              }
              return textview;
         }
     return null;
}

public LayoutInflater getLayoutInflater() {
   LayoutInflater inflater = super.getLayoutInflater();
   final LayoutInflater.Factory2 factory2 = inflater.getFactory2();
    Class cls = LayoutInflater.class;
    Field bool = cls.getDeclaredField("mFactorySet");
    bool.setAccessible(true);
    bool.setBoolean(inflater, false);
    inflater.setFactory2(new WrapFacory2(factory2));
    return inflater;
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    getLayoutInflater(); //改造已经存在的 LayoutInflater 对象
    setContentView(R.layout.activity_main);
}

private class WrapFactory2 implements LayoutInflater.Factory2 {
    LayoutInflater.Factory2 factory2;
    public WrapFactory2(LayoutInflater.Factory2 factory2) {
        this.factory2 = factory2;
    }
    @Override
    public View onCreateView(View parent, String name, Context context, AttributeSet attrs) {
        View view = factory2.onCreateView(parent, name, context, attrs);
        if(view instanceof TextView){ //支持所有 TextView 的子类，如Button
            int count = attrs.getAttributeCount();
            for (int i = 0; i < count; i++) {
                if(attrs.getAttributeName(i).equals("customfont")){
                    String path = attrs.getAttributeValue(i);
                    Typeface typeface = Typeface.createFromAsset(getAssets(), path);
                    ((TextView)view).setTypeface(typeface);
                }
            }
        }
        return view;
    }
}

if(attrs.getAttributeName(i).equals("style")){
    int styleId = attrs.getStyleAttribute();
   TypedArray ta = obtainStyledAttributes(styleId, new int[]{R.attr.customFont});
   String path = ta.getString(1);
   ta.recycle();
   Typeface typeface = Typeface.createFromAsset(getAssets(), path);
   ((TextView)view).setTypeface(typeface);
}

@Override
public View onCreateView(View parent, String name, Context context, AttributeSet attrs) {
    View view = factory2.onCreateView(parent, name, context, attrs);
    if(view instanceof TextView && attrs!=null){
        TypedArray ta = getTheme().obtainStyledAttributes(new int[]{
            android.R.attr.colorAccent,  //这里必须要以系统属性开头，否则自定义属性将解析错误
            R.attr.customFont,           //原因有待探索
         });
        String path = ta.getString(1);
        ta.recycle();
        Typeface typeface = Typeface.createFromAsset(getAssets(), path);
        ((TextView)view).setTypeface(typeface);
    }
    return view;
}

//内容控件不能有 parent
public PopupWindow(View contentView, int width, int height, boolean focusable)

//此处 View 主要是提供窗口服务的 IBinder 对象，因此随便一个控件即可以。
void showAtLocation(View parent, int gravity, int x, int y)

public void showAsDropDown(View anchor)

p.setEnterTransition(new TransitionSet().addTransition(new Slide(Gravity.BOTTOM)));
p.setExitTransition(new TransitionSet().addTransition(new Slide(Gravity.RIGHT)));

MenuItem searchItem = menu.findItem(R.id.action_search);
SearchView searchView = (SearchView) searchItem.getActionView();
MenuItemCompat.setOnActionExpandListener(searchItem, ...);
MenuItemCompat.expandActionView(searchItem);

PopupMenu popupMenu = new PopupMenu(this, textView);
popupMenu.getMenuInflater().inflate(R.menu.main, popupMenu.getMenu());
textView.setOnTouchListener(popupMenu.getDragToOpenListener());
popupMenu.show();

ArrayList<View> outViews = new ArrayList<View>();
String overflowDescription = activity.getString("more options");
decorView.findViewsWithText(outViews, overflowDescription, View.FIND_VIEWS_WITH_CONTENT_DESCRIPTION);
TintImageView overflow=(TintImageView) outViews.get(0);
overflow.setImageResource(imageID);

Builder setAdapter(final ListAdapter adapter, final OnClickListener listener)

BottomSheetDialog dialog=new BottomSheetDialog(this);
dialog.setContentView(dialogView);
dialog.show();

private View wrapInBottomSheet(int layoutResId, View view, ViewGroup.LayoutParams params) {
    CoordinatorLayout coordinator = inflate(context,
            R.layout.design_bottom_sheet_dialog, null);
    FrameLayout bottomSheet = (FrameLayout) coordinator.findViewById(R.id.design_bottom_sheet);
    mBehavior = BottomSheetBehavior.from(bottomSheet);
    mBehavior.setBottomSheetCallback(mBottomSheetCallback);
    bottomSheet.addView(view, params);
    coordinator.findViewById(R.id.touch_outside).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if (mCancelable && isShowing() && shouldWindowCloseOnTouchOutside()) {
                cancel();
            }
        }
    });
    return coordinator;
}

private BottomSheetBehavior<FrameLayout> mBehavior;

Dialog onCreateDialog(Bundle savedInstanceState)

void show(FragmentManager manager, String tag)
int show(FragmentTransaction transaction, String tag)

public void dismiss();

public LayoutInflater getLayoutInflater(Bundle savedInstanceState) {
  
    if (!mShowsDialog) {
        return super.getLayoutInflater(savedInstanceState);
    }
    mDialog = onCreateDialog(savedInstanceState);
    if (mDialog != null) {
        setupDialog(mDialog, mStyle);
        return (LayoutInflater) mDialog.getContext().getSystemService(
                Context.LAYOUT_INFLATER_SERVICE);
    }
    return (LayoutInflater) mHost.getContext().getSystemService(
            Context.LAYOUT_INFLATER_SERVICE);
}

new AlertDialog.Builder(this, R.style.Test);

context.getTheme().resolveAttribute(R.attr.alertDialogTheme, outValue, true);

dialog.setOnShowListener(new DialogInterface.OnShowListener() {
    @Override
    public void onShow(DialogInterface d) {
        View view = dialog.getWindow().getDecorView();
        view.animate().rotation(360).setDuration(2000).start();
    }
});

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

@Override
public void dismiss() {
    animatorSet = new AnimatorSet();
    setupAnim();
    animatorSet.addListener(new Animator.AnimatorListener() {
        @Override
        public void onAnimationEnd(Animator animation) {
            AnimDialog.super.dismiss();
        }
    });
    animatorSet.resume();
}

public static AnimDialog create(Context context) {
    return new AnimDialog(context);
}

ObjectAnimator.ofFloat(view, "rotationY", -90, 0).setDuration(mDuration)

ObjectAnimator.ofFloat(view, "translationX", 0, .10f, -25, .26f, 25,.42f, -25, .58f, 25,.74f,-25,.90f,1,0)

ObjectAnimator.ofFloat(view, "rotationY", 90, 0).setDuration(2000), //负责旋转ObjectAnimator.ofFloat(view, "translationX", -300, 0).setDuration(2000), //负责左侧ObjectAnimator.ofFloat(view, "alpha", 0, 1).setDuration(2000*3/2)

ObjectAnimator.ofFloat(view, "rotationY", 90,88,88,45,0).setDuration(2000),
ObjectAnimator.ofFloat(view, "alpha", 0,0.4f,0.8f, 1).setDuration(2000*3/2),
ObjectAnimator.ofFloat(view, "scaleX", 0,0.5f, 0.9f, 0.9f, 1).setDuration(2000),
ObjectAnimator.ofFloat(view,"scaleY",0,0.5f, 0.9f, 0.9f, 1).setDuration(2000)

ObjectAnimator.ofFloat(view, "rotation", 1080,720,360,0).setDuration(2000),
ObjectAnimator.ofFloat(view, "alpha", 0, 1).setDuration(2000*3/2),
ObjectAnimator.ofFloat(view, "scaleX", 0.1f, 0.5f, 1).setDuration(2000),
ObjectAnimator.ofFloat(view,"scaleY",0.1f,0.5f,1).setDuration(2000)

public class TreeNode {
  private TreeNode mParent; 
  private final List<TreeNode> children;
  private BaseNodeViewHolder mViewHolder;//布局
}

Rect rect = new Rect();
anchorView.getGlobalVisibleRect(rect);
int[] location = new int[2];
mFloatingDecorView.getLocationOnScreen(location);
rect.offset(-location[0], -location[1]);
//anchorView 的测量和布局
mFloatingDecorView.addView(targetView,lp);
//此后是应用动画

public static Toast makeText(Context context, CharSequence text, @Duration int duration) {
    Toast result = new Toast(context);
    View v = inflate.inflate(com.android.internal.R.layout.transient_notification, null);
    TextView tv = (TextView)v.findViewById(com.android.internal.R.id.message);
    tv.setText(text);
    
    result.mNextView = v;
    result.mDuration = duration;
    return result;
}

public void show() {
    if (mNextView == null) {
        throw new RuntimeException("setView must have been called");
    }
    tn.mNextView = mNextView;
    INotificationManager service = getService();
    String pkg = mContext.getOpPackageName();
    TN tn = mTN;
    service.enqueueToast(pkg, tn, mDuration);
}

WindowManager mWM = (WindowManager)context.getSystemService(Context.WINDOW_SERVICE);
mParams.gravity = gravity;
mWM.addView(mView, mParams);

@Override
protected void onAttachedToWindow() {
    super.onAttachedToWindow();
    ValueAnimator va = ValueAnimator.ofInt(Color.GREEN, Color.CYAN).setDuration(1500);
    va.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
        @Override
        public void onAnimationUpdate(ValueAnimator animation) {
            drawable.setColor((Integer) animation.getAnimatedValue());
        }
    });
    va.start();
}

public static Snackbar make(View view, int resId, @Duration int duration)

private final ViewGroup mTargetParent;
final SnackbarLayout mView;
private Snackbar(ViewGroup parent) {
    mTargetParent = parent;
    mView = (SnackbarLayout) inflater.inflate(
            R.layout.design_layout_snackbar, mTargetParent, false);
}

private SnackbarRecord mCurrentSnackbar;
private SnackbarRecord mNextSnackbar;

final void showView() {
    if (mView.getParent() == null) {
        final ViewGroup.LayoutParams lp = mView.getLayoutParams();
        if (lp instanceof CoordinatorLayout.LayoutParams) {
            CoordinatorLayout.LayoutParams clp = (CoordinatorLayout.LayoutParams) lp;
            Behavior behavior = new Behavior();
            behavior.setListener(new SwipeDismissBehavior.OnDismissListener());
            clp.setBehavior(behavior);
            clp.insetEdge = Gravity.BOTTOM;
        }
        mTargetParent.addView(mView);
        //使用动画
    }
}

NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
Notification compat = new NotificationCompat.Builder(this)
        .setSmallIcon(R.drawable.boot)
        .setContentText("通知必须有：标题，内容和显示在状态栏的Small图标")
        .setContentTitle("标题")
        .setLargeIcon(BitmapFactory.decodeResource(getResources(), R.drawable.beauty))
        .setSubText("子标题")          
        .setCustomBigContentView(remoteViews) //大图
        .setAutoCancel(true) //点击取消
        .setTicker("通知") //显示在状态栏的标题
        .setDefaults(Notification.DEFAULT_ALL) //效果
        .build();
manager.notify("like", 6, compat);

public class FadeDrawable extends BitmapDrawable {
    private long mStartTime = 0;
    private long mDuration = 2000;
    @Override
    public void draw(Canvas canvas) {
        super.draw(canvas);
        long time = System.currentTimeMillis() - mStartTime;
        if(time<mDuration){
            int alpha = (int) (255 * max(0, time) / mDuration);
            setAlpha(alpha);
            invalidateSelf();
        } else {
            setAlpha(255);
        }
    }
    public void fade(){
        mStartTime = System.currentTimeMillis();
        invalidateSelf();
    }
}

ValueAnimator va = ValueAnimator.ofInt(0, 255).setDuration(2000);
va.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            @Override
            public void onAnimationUpdate(ValueAnimator animation) {
                bitmapDrawable.setAlpha((Integer) animation.getAnimatedValue());
            }
        });
va.start();

mImageView.animate().alpha(1f).withLayer().setDuration(2000).start();

@Override
protected void onBoundsChange(Rect bounds) {
    super.onBoundsChange(bounds);
    createPath();

private float[][] as = new float[2][5];

Property<View, float[][]> mBProperty = new Property<View, float[][]>(float[][].class, "bs")

@Override
public void draw(Canvas canvas) {
    Rect bounds = getBounds();
    int width = bounds.width();
    int height = bounds.height();
    float midX = 0;
    float midY = bounds.centerY();
    float topY = lerp(midY - height / 3, midY, mProgress);
    float botY = lerp(midY + height / 3, midY, mProgress);
    float dx = lerp(width, width / 2, mProgress);
    mPath.rewind();
    // draw middle bar
    mPath.moveTo(midX, midY);
    mPath.rLineTo(width, 0);
    // bottom bar
    mPath.moveTo(midX, botY);
    mPath.rLineTo(dx, midY + height / 3 - botY);
    // top bar
    mPath.moveTo(midX, topY);
    mPath.rLineTo(dx, midY - height / 3 - topY); 
    mPath.close();
    canvas.save();
    
    float rotate = lerp(0, 270, mProgress);  //将 Path 旋转，区间为[0, 270]
    canvas.rotate(rotate, bounds.centerX(), bounds.centerY());
    canvas.drawPath(mPath, mPaint);
    canvas.restore();
}

@Override
public void draw(Canvas canvas) {
    super.draw(canvas);
    Rect r = getBounds();
    int count = canvas.save();
    canvas.translate(r.left, r.top);
    int width = this.width < 0 ? r.width() : this.width;
    int height = this.height < 0 ? r.height() : this.height; 
    //字体尺寸不超过高度的一半
    int fontSize = this.fontSize < 0 ? (Math.min(width, height) / 2) : this.fontSize;
    textPaint.setTextSize(fontSize);
    canvas.drawText(text, width / 2, height / 2 - ((textPaint.descent() + textPaint.ascent()) / 2), textPaint);
    canvas.restoreToCount(count);
}

Drawable[] layerList = {
        new InsetDrawable(left, 0, 0, toPx(31), 0),
        new InsetDrawable(right, toPx(31), 0, 0, 0)
};
return new LayerDrawable(layerList);

AnimationDrawable animationDrawable = new AnimationDrawable();
for (int i = 10; i > 0; i--) {
    TextDrawable frame = builder.build(String.valueOf(i), mGenerator.getRandomColor());
    animationDrawable.addFrame(frame, 1200);
}
animationDrawable.setOneShot(false);
animationDrawable.start();

@Override
public void draw(Canvas c) {
    final Rect bounds = getBounds();
    final int saveCount = c.save();
    c.rotate(mRotation, bounds.exactCenterX(), bounds.exactCenterY());
    mRing.draw(c, bounds);
    c.restoreToCount(saveCount);
}

public float getX() {    
    return mLeft + getTranslationX();
}

public void invalidate(Rect dirty) {
    final int scrollX = mScrollX;
    final int scrollY = mScrollY;
    invalidateInternal(dirty.left - scrollX, dirty.top - scrollY,
            dirty.right - scrollX, dirty.bottom - scrollY, true, false);
}

public void setFillBefore(boolean fillBefore);
public void setFillAfter(boolean fillAfter);

@Override
protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
    return p instanceof LayoutParams;
}
@Override
public LayoutParams generateLayoutParams(AttributeSet attrs) {
    return new LayoutParams(getContext(), attrs);
}
@Override
protected LayoutParams generateDefaultLayoutParams() {
    return new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
}
@Override
protected LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
    return new LayoutParams(p);
}

protected void measureChild(View child, int parentWidthMeasureSpec,
        int parentHeightMeasureSpec) {
    final LayoutParams lp = child.getLayoutParams();
    final int childWidthMeasureSpec = getChildMeasureSpec(parentWidthMeasureSpec,
            mPaddingLeft + mPaddingRight, lp.width);
    final int childHeightMeasureSpec = getChildMeasureSpec(parentHeightMeasureSpec,
            mPaddingTop + mPaddingBottom, lp.height);
    child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
}

//spec 的复合尺寸，padding 是控件的留白
//childDimension 是赋给LayoutParams的尺寸，是控件想达到的尺寸，可能是 -1 -2 或 具体数值
public static int getChildMeasureSpec(int spec, int padding, int childDimension) {
    int specMode = MeasureSpec.getMode(spec); // 容器的尺寸模式
    int specSize = MeasureSpec.getSize(spec); // 容器的尺寸大小
    int size = Math.max(0, specSize - padding); // 容器的尺寸大小 - 控件的留白 == 控件在容器中的最大尺寸
    int resultSize = 0;
    int resultMode = 0;
	// 根据 LayoutParams 和 MeasureSpec 确定最终的复合尺寸
    return MeasureSpec.makeMeasureSpec(resultSize, resultMode);
}

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    setMeasuredDimension(getDefaultSize(getSuggestedMinimumWidth(), widthMeasureSpec),
            getDefaultSize(getSuggestedMinimumHeight(), heightMeasureSpec));
}

//size 是最小尺寸，measureSpec 是复合尺寸
public static int getDefaultSize(int size, int measureSpec) {}

private void setMeasuredDimensionRaw(int measuredWidth, int measuredHeight) {
    mMeasuredWidth = measuredWidth;
    mMeasuredHeight = measuredHeight;
}

/**
 * @param size How big the view wants to be.
 * @param measureSpec Constraints imposed by the parent.
 * @param childMeasuredState Size information bit mask for the view's children.
 */
public static int resolveSizeAndState(int size, int measureSpec, int childMeasuredState);

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    setMeasuredDimension(
      resolveSizeAndState(getSuggestedMinimumWidth(), widthMeasureSpec, MEASURED_STATE_MASK),
      resolveSizeAndState(getSuggestedMinimumHeight(), heightMeasureSpec, MEASURED_STATE_MASK));
}

mContent.measure(
   MeasureSpec.makeMeasureSpec(
        getMeasuredWidth() - getPaddingLeft() - getPaddingRight(), MeasureSpec.EXACTLY), 
   MeasureSpec.makeMeasureSpec(
        getMeasuredHeight() - getPaddingTop() - getPaddingBottom(), MeasureSpec.EXACTLY)
);

@Override
protected void onMeasure(int widthSpec, int heightSpec) {
    switch (MeasureSpec.getMode(widthSpec)) {
        case MeasureSpec.EXACTLY:
            // Nothing to do
            break;
        case MeasureSpec.AT_MOST:
            widthSpec = MeasureSpec.makeMeasureSpec(
                    Math.min(MeasureSpec.getSize(widthSpec), mMaxWidth), MeasureSpec.EXACTLY);
            break;
        case MeasureSpec.UNSPECIFIED:
            widthSpec = MeasureSpec.makeMeasureSpec(mMaxWidth, MeasureSpec.EXACTLY);
            break;
    }
    // Let super sort out the height
    super.onMeasure(widthSpec, heightSpec);
}

public boolean dispatchTouchEvent(MotionEvent ev) {
    if (getWindow().superDispatchTouchEvent(ev)) {
        return true;
    }
    return onTouchEvent(ev);
}

getParent().requestDisallowInterceptTouchEvent(true);

public boolean onInterceptTouchEvent(MotionEvent ev) {
    boolean isIntercept = false;
    int action = ev.getAction();
    switch (action) {
        case MotionEvent.ACTION_DOWN:
            isIntercept = false;
            break;
        case MotionEvent.ACTION_MOVE:
            if ("左右滑动") {
                isIntercept = true;
            }
            break;
        case MotionEvent.ACTION_UP:
        default:
            isIntercept = false;
            break;
    }
    return isIntercept;
}

@Override
public boolean dispatchTouchEvent(MotionEvent event) {
    //只处理 ACTION_UP，防止执行多个动画，造成View参数紊乱
    if(event.getAction() == MotionEvent.ACTION_UP) { 
        ViewCompat.animate(view).setDuration(duration)
          .scaleX(scale).scaleY(scale).setInterpolator(new CycleInterpolator(0.5f))
          .withLayer()
          .start();
    }
    return super.dispatchTouchEvent(event);
}

final int action = MotionEventCompat.getActionMasked(event);
final int actionIndex = MotionEventCompat.getActionIndex(event);
int pointerCount = event.getPointerCount();
for (int i = 0; i < pointerCount; i++) {
    int pointerId = event.getPointerId(i);
    float x = event.getX(actionIndex);
    float y = event.getY(actionIndex);
}

//1.启动滚动过程
mScroller.startScroll(getScrollX(), getScrollY(), 100, 100);
invalidate();
//2.自我驱动
@Override
public void computeScroll() {
    if (mScroller != null) {
        if (mScroller.computeScrollOffset()) {                    //判断是否完成
            scrollTo(mScroller.getCurrX(), mScroller.getCurrY()); //实现滚动的一小步 
            setAlpha(1f*scroller.getCurrX()/scroller.getFinalX());//附加效果
            postInvalidate();                                     //实现滚动循环
        }
    }

public void getDrawingRect(Rect outRect) {    
    outRect.left = mScrollX;    
    outRect.top = mScrollY;    
    outRect.right = mScrollX + (mRight - mLeft);    
    outRect.bottom = mScrollY + (mBottom - mTop);
}

public void startAnimation(Animation animation)

public void setStateListAnimator(StateListAnimator stateListAnimator);

public ViewPropertyAnimator animate();

public void onPull(float deltaDistance, float displacement)

@Override
public void draw(Canvas canvas) {
    super.draw(canvas);
    edge.setSize(getWidth(), getHeight());
    if (!edge.isFinished()) {
        final int restoreCount = canvas.save();
        if(edge.draw(canvas)){
            postInvalidate();
        }
        canvas.restoreToCount(restoreCount);
    }
}

canvas.rotate(90); //画布旋转90度，意味着坐标轴也偏移了90度，
canvas.translate(0,-getWidth()); //此时 y 轴实际是向左，故而反向回退一个宽度，矫正弧顶矩形
edge.setSize(getHeight(), getWidth());

canvas.rotate(270); //画布旋转270度，此时y轴向右
canvas.translate(-getHeight(), 0);//弧顶矩形需要下移
edge.setSize(getHeight(), getWidth());

canvas.rotate(180);
canvas.translate(-getWidth(), -getHeight());
edge.setSize(getWidth(), getHeight());

SurfaceView surfaceView = (SurfaceView) findViewById(R.id.surfaceview);
//1. 获取 SurfaceView 对象内部类SurfaceHolder
SurfaceHolder holder = surfaceView.getHolder();
//2. SurfaceHolder对象添加Callback接口，执行在UI线程
holder.addCallback(new SurfaceHolder.Callback() {
    @Override
    public void surfaceCreated(SurfaceHolder holder)
    
    //4.Surface设置参数被改变将调用此回调方法，实现主要绘制逻辑
    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
        //1. 通过锁定获取canvas对象，开始编辑底层像素
        Canvas canvas = holder.lockCanvas();
        canvas.drawColor(0x4398ff);
        //2. 消除canvas对象，结束像素编辑
        holder.unlockCanvasAndPost(canvas);
        //3. 再次锁定并取消锁定
        canvas = holder.lockCanvas(new Rect(0, 0, 0, 0));
        holder.unlockCanvasAndPost(canvas);
    }
    @Override
    public void surfaceDestroyed(SurfaceHolder holder)
});

public interface OnPreDrawListener {
    public boolean onPreDraw();
}

ViewStub stub = (ViewStub) findViewById(R.id.stub);
View inflated = stub.inflate();

public int gravity = UNSPECIFIED_GRAVITY;

final int layoutDirection = getLayoutDirection();
final int absoluteGravity = Gravity.getAbsoluteGravity(gravity, layoutDirection);
final int verticalGravity = gravity & Gravity.VERTICAL_GRAVITY_MASK;

switch (absoluteGravity & Gravity.HORIZONTAL_GRAVITY_MASK) {
    case Gravity.CENTER_HORIZONTAL:
        childLeft = parentLeft + (parentRight - parentLeft - width) / 2 +
        lp.leftMargin - lp.rightMargin;
    case Gravity.RIGHT:
        childLeft = parentRight - width - lp.rightMargin;
    case Gravity.LEFT:
        childLeft = parentLeft + lp.leftMargin;
}
child.layout(childLeft, childTop, childLeft + width, childTop + height);

@Override
protected void onAttachedToWindow() {
    super.onAttachedToWindow();
    final IntentFilter filter = new IntentFilter();
    filter.addAction(Intent.ACTION_SCREEN_OFF);
    filter.addAction(Intent.ACTION_USER_PRESENT);
    getContext().registerReceiverAsUser(mReceiver, android.os.Process.myUserHandle(),
            filter, null, getHandler());
    if (mAutoStart) {
        startFlipping();
    }
}
@Override
protected void onDetachedFromWindow() {
    super.onDetachedFromWindow();
    mVisible = false;
    getContext().unregisterReceiver(mReceiver);
    updateRunning();
}

int range = getScrollRange();//计算滑动范围int 
overscrollMode = getOverScrollMode();//计算覆盖滑动方式
boolean canOverscroll = overscrollMode == OVER_SCROLL_ALWAYS ||(overscrollMode == OVER_SCROLL_IF_CONTENT_SCROLLS && range > 0);

Math.max(0,child.getWidth() - (getWidth() - mPaddingLeft - mPaddingRight);

//mOverscrollDistance 指的是触发边界效应的距离
overScrollBy(deltaX, 0, mScrollX, 0, range, 0, mOverscrollDistance, 0, true)

View view = getChildAt(0);
mTempRect.right = view.getRight();
mTempRect.left = mTempRect.right - width;

TransitionManager.beginDelayedTransition(sceneRoot);//默认采用A utoTransition

Scene scene = new Scene(sceneRoot, textView);
TransitionManager.go(scene, new Fade(Fade.IN));

public final class Scene {
    private Context mContext;
    private int mLayoutId = -1; //待加入到根布局中的布局，必须没有父控件
    private ViewGroup mSceneRoot; //根布局，必须已经存在
    private View mLayout; // alternative to layoutId
    Runnable mEnterAction, mExitAction;
}

public void enter() {
    getSceneRoot().removeAllViews();
  
    mSceneRoot.addView(mLayout);
    LayoutInflater.from(mContext).inflate(mLayoutId, mSceneRoot);
    mEnterAction.run();
  
    setCurrentScene(mSceneRoot, this);
}

static Scene getCurrentScene(View view) {
    return (Scene) view.getTag(com.android.internal.R.id.current_scene);
}

public class TransitionManager {
    private static Transition sDefaultTransition = new AutoTransition();
    ArrayMap<Scene, Transition> mSceneTransitions = new ArrayMap<Scene, Transition>();
    ArrayMap<Scene, ArrayMap<Scene, Transition>> mScenePairTransitions =
            new ArrayMap<Scene, ArrayMap<Scene, Transition>>();
    private static ArrayList<ViewGroup> sPendingTransitions = new ArrayList<ViewGroup>();
}

public void setTransition(Scene fromScene, Scene toScene, Transition transition) {
    ArrayMap<Scene, Transition> sceneTransitionMap = mScenePairTransitions.get(toScene);
    sceneTransitionMap.put(fromScene, transition);
}

//这里Scene表示进入场景，而 sceneRoot 中存储的是当前场景，即将要离开的场景，在播放完成后要被删除；
//因此先获取的是离开场景，离开Transition播放完成后将获取进入场景。
private Transition getTransition(Scene scene) {
    Transition transition = null;
    ViewGroup sceneRoot = scene.getSceneRoot();
    if (sceneRoot != null) {
        Scene currScene = Scene.getCurrentScene(sceneRoot);
        if (currScene != null) {
            ArrayMap<Scene, Transition> sceneTransitionMap = mScenePairTransitions.get(scene);
            if (sceneTransitionMap != null) {
                transition = sceneTransitionMap.get(currScene);
                if (transition != null) {
                    return transition;
                }
            }
        }
    }
    transition = mSceneTransitions.get(scene);
    return (transition != null) ? transition : sDefaultTransition;
}

//1.准备工作1：清理先前的 Transition，包括 TransitionManager 和 sceneRoot 内部存储的两部分
ArrayList<Transition> runningTransitions = getRunningTransitions().get(sceneRoot);
for (Transition runningTransition : runningTransitions) {
    runningTransition.pause(sceneRoot);
}
Scene previousScene = Scene.getCurrentScene(sceneRoot);
previousScene.exit();
//2.准备工作2：新的 Transition 获取初始值，并清理掉 sceneRoot内部存储的 Scene 对象
transition.captureValues(sceneRoot, true);
Scene.setCurrentScene(sceneRoot, null);
//3.在视图树中埋点
sceneRoot.getViewTreeObserver().addOnPreDrawListener(listener);
mTransition.captureValues(mSceneRoot, false);
mTransition.playTransition(mSceneRoot);

//1.清理监听器和 Transition 集合
removeListeners();
sPendingTransitions.remove(mSceneRoot);
//2.此时布局过程已经完成，绘制还没有开始，是 Transition 获取终止值的绝佳时机。
mTransition.captureValues(mSceneRoot, false);
//3.起始值均已捕获，执行动画的条件已经成熟。
mTransition.playTransition(mSceneRoot);