custom_menu.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="48dp"
    android:layout_height="48dp"
    android:background="?attr/actionBarItemBackground"
    android:clickable="true"
    android:focusable="true"
    android:minHeight="48dp"
    android:minWidth="48dp">

    <ImageView
        android:id="@+id/menu_badge_icon"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="center"
        android:layout_marginLeft="12dp"
        android:layout_marginRight="12dp"
        android:scaleType="center"
        android:tint="@android:color/white" />

    <com.utycc.library.MaterialBadgeTextView
        android:id="@+id/menu_badge"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="top|end"
        android:background="#EF4738"
        android:ellipsize="none"
        android:gravity="center"
        android:singleLine="true"
        android:textColor="@android:color/white"
        android:textSize="10sp"
        android:textStyle="bold" />
</FrameLayout>

MaterialBadgeTextView.java

public class MaterialBadgeTextView extends TextView {

    private static final int DEFAULT_FILL_TYPE = 0;

    private int backgroundColor;
    private int borderColor;
    private float borderWidth;
    private float borderAlpha;
    private int ctType;

    private static final float SHADOW_RADIUS = 3.5f;
    private static final int FILL_SHADOW_COLOR = 0x55000000;
    private static final int KEY_SHADOW_COLOR = 0x55000000;

    private static final float X_OFFSET = 0f;
    private static final float Y_OFFSET = 1.75f;


    private float density;
    private int mShadowRadius;
    private int shadowYOffset;
    private int shadowXOffset;

    private int basePadding;
    private int diffWH;

    private boolean isHighLightMode;

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

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

    public MaterialBadgeTextView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context, attrs);
    }

    private void init(Context context, AttributeSet attrs) {
        setGravity(Gravity.CENTER);
        density = getContext().getResources().getDisplayMetrics().density;
        mShadowRadius = (int) (density * SHADOW_RADIUS);
        shadowYOffset = (int) (density * Y_OFFSET);
        shadowXOffset = (int) (density * X_OFFSET);
        basePadding = (mShadowRadius * 2);
        float textHeight = getTextSize();
        float textWidth = textHeight / 4;
        diffWH = (int) (Math.abs(textHeight - textWidth) / 2);
        int horizontalPadding = basePadding + diffWH;
        setPadding(horizontalPadding, basePadding, horizontalPadding, basePadding);
        TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.MaterialBadgeTextView);
        backgroundColor = typedArray.getColor(R.styleable.MaterialBadgeTextView_android_background, Color.WHITE);
        borderColor = typedArray.getColor(R.styleable.MaterialBadgeTextView_mbtv_border_color, Color.TRANSPARENT);
        borderWidth = typedArray.getDimension(R.styleable.MaterialBadgeTextView_mbtv_border_width, 0);
        borderAlpha = typedArray.getFloat(R.styleable.MaterialBadgeTextView_mbtv_border_alpha, 1);
        ctType = typedArray.getInt(R.styleable.MaterialBadgeTextView_mbtv_type, DEFAULT_FILL_TYPE);
        typedArray.recycle();
    }

    @Override
    protected void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) {
        super.onTextChanged(text, start, lengthBefore, lengthAfter);
        /** 纯色小红点模式下若有文本需要从无变为有, 要归位view的大小.*/
        String strText = text==null?"":text.toString().trim();
        if(isHighLightMode && !"".equals(strText)){
            ViewGroup.LayoutParams lp = getLayoutParams();
            lp.height = ViewGroup.LayoutParams.WRAP_CONTENT;
            lp.width = ViewGroup.LayoutParams.WRAP_CONTENT;
            setLayoutParams(lp);
            isHighLightMode = false;
        }
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        refreshBackgroundDrawable(w, h);
    }

    private void refreshBackgroundDrawable(int targetWidth, int targetHeight) {
        if (targetWidth <= 0 || targetHeight <= 0) {
            return;
        }
        CharSequence text = getText();
        if (text == null) {
            return;
        }
        if (text.length() == 1) {/**第一种背景是一个正圆形, 当文本为个位数字时 */
            int max = Math.max(targetWidth, targetHeight);
            ShapeDrawable circle;
            final int diameter = max - (2 * mShadowRadius);
            OvalShape oval = new OvalShadow(mShadowRadius, diameter);
            circle = new ShapeDrawable(oval);
            ViewCompat.setLayerType(this, ViewCompat.LAYER_TYPE_SOFTWARE, circle.getPaint());
            circle.getPaint().setShadowLayer(mShadowRadius, shadowXOffset, shadowYOffset, KEY_SHADOW_COLOR);
            circle.getPaint().setColor(backgroundColor);
            if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.JELLY_BEAN) {
                setBackgroundDrawable(circle);
            } else {
                setBackground(circle);
            }
        } else if (text.length() > 1) {/**第二种背景是上下两边为直线的椭圆, 当文本长度大于1时 */
            SemiCircleRectDrawable sr = new SemiCircleRectDrawable();
            ViewCompat.setLayerType(this, ViewCompat.LAYER_TYPE_SOFTWARE, sr.getPaint());
            sr.getPaint().setShadowLayer(mShadowRadius, shadowXOffset, shadowYOffset, KEY_SHADOW_COLOR);
            sr.getPaint().setColor(backgroundColor);
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
                setBackground(sr);
            } else {
                setBackgroundDrawable(sr);
            }
        } else {
            /** 第三种情况就是text="", 即文本长度为0, 因为无任何文本, 则对当前的TextView背景不做任何更新,
             * 但是有时候我们需要一个无字的纯色小圆形,用来表达强调.这种情况因为要重新设置View的大小, 所以不在这里表现, 请使用另外一个方法setHighLightMode()来完成.
             */
        }

    }

    public void setBadgeCount(String count){
        setBadgeCount(count, false);
    }
    public void setBadgeCount(String count, boolean goneWhenZero) {
        int temp = -1;
        try {
            temp = Integer.parseInt(count);
        } catch (Exception e) {

        }
        if (temp != -1) {
            setBadgeCount(temp, goneWhenZero);
        }
    }

    public void setBadgeCount(int count){
        setBadgeCount(count, true);
    }
    public void setBadgeCount(int count, boolean goneWhenZero){
        if(count >0 && count <= 99){
            setText(String.valueOf(count));
            setVisibility(View.VISIBLE);
        }else if(count >99){
            setText("99+");
            setVisibility(View.VISIBLE);
        }else if(count <= 0){
            setText("0");
            if(goneWhenZero){
                setVisibility(View.GONE);
            }else{
                setVisibility(View.VISIBLE);
            }
        }
    }

    /**
     * 明确的展现一个无任何文本的红色圆点,
     * 主要是通过设置文本setText("")触发onTextChanged(), 再连锁触发onSizeChanged()最后更新了背景.
     */
    public void setHighLightMode(){
        setHighLightMode(false);
    }

    public void clearHighLightMode(){
        isHighLightMode = false;
        setBadgeCount(0);
    }

    /**
     *
     * @param isDisplayInToolbarMenu
     */
    public void setHighLightMode(boolean isDisplayInToolbarMenu){
        isHighLightMode = true;
        ViewGroup.LayoutParams params = getLayoutParams();
        params.width = dp2px(getContext(), 8);
        params.height = params.width;
        if(isDisplayInToolbarMenu && params instanceof FrameLayout.LayoutParams){
            ((FrameLayout.LayoutParams)params).topMargin=dp2px(getContext(), 8);
            ((FrameLayout.LayoutParams)params).rightMargin=dp2px(getContext(), 8);
        }
        setLayoutParams(params);
        ShapeDrawable drawable = new ShapeDrawable(new OvalShape());
        ViewCompat.setLayerType(this, ViewCompat.LAYER_TYPE_SOFTWARE, drawable.getPaint());
        drawable.getPaint().setColor(backgroundColor);
        drawable.getPaint().setAntiAlias(true);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
            setBackground(drawable);
        } else {
            setBackgroundDrawable(drawable);
        }
        setText("");
        setVisibility(View.VISIBLE);
    }

    public void setBackgroundColor(int color){
        backgroundColor = color;
        refreshBackgroundDrawable(getWidth(), getHeight());
    }

    private class OvalShadow extends OvalShape {
        private RadialGradient mRadialGradient;
        private Paint mShadowPaint;
        private int mCircleDiameter;

        public OvalShadow(int shadowRadius, int circleDiameter) {
            super();
            mShadowPaint = new Paint();
            mShadowRadius = shadowRadius;
            mCircleDiameter = circleDiameter;
            mRadialGradient = new RadialGradient(mCircleDiameter / 2, mCircleDiameter / 2,
                    mShadowRadius, new int[]{
                    FILL_SHADOW_COLOR, Color.TRANSPARENT
            }, null, Shader.TileMode.CLAMP);
            mShadowPaint.setShader(mRadialGradient);
        }

        @Override
        public void draw(Canvas canvas, Paint paint) {
            final int viewWidth = MaterialBadgeTextView.this.getWidth();
            final int viewHeight = MaterialBadgeTextView.this.getHeight();
            canvas.drawCircle(viewWidth / 2, viewHeight / 2, (mCircleDiameter / 2 + mShadowRadius), mShadowPaint);
            canvas.drawCircle(viewWidth / 2, viewHeight / 2, (mCircleDiameter / 2), paint);
        }
    }

    class SemiCircleRectDrawable extends Drawable {
        private final Paint mPaint;
        private RectF rectF;

        public Paint getPaint() {
            return mPaint;
        }

        public SemiCircleRectDrawable() {
            mPaint = new Paint();
            mPaint.setAntiAlias(true);
        }

        @Override
        public void setBounds(int left, int top, int right, int bottom) {
            super.setBounds(left, top, right, bottom);
            if (rectF == null) {
                rectF = new RectF(left + diffWH, top + mShadowRadius+4, right - diffWH, bottom - mShadowRadius-4);
            } else {
                rectF.set(left + diffWH, top + mShadowRadius+4, right - diffWH, bottom - mShadowRadius-4);
            }
        }

        @Override
        public void draw(Canvas canvas) {
            float R = (float)(rectF.bottom * 0.4);
            if (rectF.right < rectF.bottom) {
                R = (float)(rectF.right * 0.4);
            }
            canvas.drawRoundRect(rectF, R, R, mPaint);
        }

        @Override
        public void setAlpha(int alpha) {
            mPaint.setAlpha(alpha);
        }

        @Override
        public void setColorFilter(ColorFilter colorFilter) {
            mPaint.setColorFilter(colorFilter);
        }

        @Override
        public int getOpacity() {
            return PixelFormat.TRANSPARENT;
        }
    }

    public static int dp2px(Context context, float dpValue) {
        try {
            final float scale = context.getResources().getDisplayMetrics().density;
            return (int) (dpValue * scale + 0.5f);
        } catch (Exception e) {
            return (int) (dpValue + 0.5f);
        }
    }

}

MenuItemBadge.java

import android.app.Activity;
import android.content.Context;
import android.content.res.ColorStateList;
import android.graphics.Color;
import android.graphics.Point;
import android.graphics.drawable.Drawable;
import android.view.Display;
import android.view.Gravity;
import android.view.MenuItem;
import android.view.View;
import android.view.Window;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import static android.util.TypedValue.COMPLEX_UNIT_DIP;
import static android.util.TypedValue.applyDimension;

/**
 * @author donghua.xdh
 */
public class MenuItemBadge {

    public static class Builder{

        public int textBackgroundColor; // TRANSPARENT = 0;
        public int textColor; // TRANSPARENT = 0;
        public int iconTintColor; // TRANSPARENT = 0;
        private Drawable iconDrawable;
        public Builder(){

        }
        public Builder textBackgroundColor(int textBackgroundColor){
            this.textBackgroundColor = textBackgroundColor;
            return this;
        }

        public Builder textColor(int textColor){
            this.textColor = textColor;
            return this;
        }

        public Builder iconTintColor(int iconTintColor){
            this.iconTintColor = iconTintColor;
            return this;
        }

        public Builder iconDrawable(Drawable iconDrawable){
            this.iconDrawable = iconDrawable;
            return this;
        }

    }

//    public static void update(final MenuItem menu, int badgeCount) {
//        update(null,menu, null, String.valueOf(formatNumber(badgeCount,true)));
//    }

    public static void update(final Activity activity, final MenuItem menu, MenuItemBadge.Builder builder) {
        update(activity, menu, builder, null);

    }

    public static void update(final Activity activity, final MenuItem menu, MenuItemBadge.Builder builder, final ActionItemBadgeListener listener) {
        if (menu == null) return;
        FrameLayout badge;
        MaterialBadgeTextView badgeTextView;
        ImageView imageView;

        badge = (FrameLayout) menu.getActionView();

        badgeTextView = (MaterialBadgeTextView) badge.findViewById(R.id.menu_badge);
        imageView = (ImageView) badge.findViewById(R.id.menu_badge_icon);

        //Display icon in ImageView
        if(imageView != null && builder != null){
            if (builder.iconDrawable !=null) {
                imageView.setImageDrawable(builder.iconDrawable);
            }

            if (  builder.iconTintColor != Color.TRANSPARENT) {
                imageView.setColorFilter(builder.iconTintColor);
            }
        }

        if (badgeTextView != null && builder != null && builder.textBackgroundColor != Color.TRANSPARENT) {
            badgeTextView.setBackgroundColor(builder.textBackgroundColor);
        }

        if (badgeTextView != null && builder != null && builder.textColor != Color.TRANSPARENT) {
            badgeTextView.setTextColor(builder.textColor);
        }


        //Bind onOptionsItemSelected to the activity
        if (activity != null) {
            badge.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    boolean consumed = false;
                    if (listener != null) {
                        consumed = listener.onOptionsItemSelected(menu);
                    }
                    if (!consumed) {
                        activity.onMenuItemSelected(Window.FEATURE_OPTIONS_PANEL, menu);
                    }
                }
            });

            badge.setOnLongClickListener(new View.OnLongClickListener() {
                @Override
                public boolean onLongClick(View v) {
                    Display display = activity.getWindowManager().getDefaultDisplay();
                    Point size = new Point();
                    display.getSize(size);
                    int width = size.x;
                    Toast toast = Toast.makeText(activity, menu.getTitle(), Toast.LENGTH_SHORT);
                    toast.setGravity(Gravity.TOP, width / 5, convertDpToPx(activity, 48));
                    toast.show();
                    return true;
                }
            });
        }

        menu.setVisible(true);
    }

    public static MaterialBadgeTextView getBadgeTextView(MenuItem menu) {
        if (menu == null) {
            return null;
        }
        FrameLayout badge = (FrameLayout) menu.getActionView();
        MaterialBadgeTextView badgeView = (MaterialBadgeTextView) badge.findViewById(R.id.menu_badge);
        return badgeView;
    }

    /**
     * hide the given menu item
     *
     * @param menu
     */
    public static void hide(MenuItem menu) {
        menu.setVisible(false);
    }


    public interface ActionItemBadgeListener {
        boolean onOptionsItemSelected(MenuItem menu);
    }

    public static int convertDpToPx(Context context, float dp) {
        return (int) applyDimension(COMPLEX_UNIT_DIP, dp, context.getResources().getDisplayMetrics());
    }

    public static void setBackgroundCompat(View v, Drawable d) {
        if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.JELLY_BEAN) {
            v.setBackgroundDrawable(d);
        } else {
            v.setBackground(d);
        }
    }

    public static String formatNumber(int value,boolean limitLength) {
        if (value < 0) {
            return "-" + formatNumber(-value, limitLength);
        } else if (value < 100) {
            return Long.toString(value);
        } else {
            return "99+";
        }

    }
}