红点

1、对应的控件

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Color;
import android.graphics.drawable.ShapeDrawable;
import android.graphics.drawable.shapes.RoundRectShape;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.view.ViewParent;
import android.view.animation.AccelerateInterpolator;
import android.view.animation.AlphaAnimation;
import android.view.animation.Animation;
import android.view.animation.DecelerateInterpolator;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.TabWidget;




public class BadgeView extends ImageView {


    public static final int POSITION_TOP_LEFT = 1;
    public static final int POSITION_TOP_RIGHT = 2;
    public static final int POSITION_BOTTOM_LEFT = 3;
    public static final int POSITION_BOTTOM_RIGHT = 4;


    private static final int DEFAULT_MARGIN_DIP = 5;


    public int MARGIN_LEFT = DEFAULT_MARGIN_DIP;
    public int MARGIN_TOP = DEFAULT_MARGIN_DIP;
    public int MARGIN_RIGHT = DEFAULT_MARGIN_DIP;
    public int MARGIN_BOTTOM = DEFAULT_MARGIN_DIP;


    private static final int DEFAULT_CORNER_RADIUS_DIP = 8;
    private static final int DEFAULT_POSITION = POSITION_TOP_RIGHT;
    private static final int DEFAULT_BADGE_COLOR = Color.RED;


    private Animation fadeIn;
    private Animation fadeOut;


    private Context context;
    private View target;


    private int badgePosition;
    private int badgeMargin;
    private int badgeColor;


    private boolean isShown;


    private ShapeDrawable badgeBg;


    private int targetTabIndex;


    public BadgeView(Context context) {
        this(context, (AttributeSet) null, android.R.attr.textViewStyle);
    }


    public BadgeView(Context context, AttributeSet attrs) {
        this(context, attrs, android.R.attr.textViewStyle);
    }


    public BadgeView(Context context, View target) {
        this(context, null, android.R.attr.textViewStyle, target, 0);
    }


    public BadgeView(Context context, TabWidget target, int index) {
        this(context, null, android.R.attr.textViewStyle, target, index);
    }


    public BadgeView(Context context, AttributeSet attrs, int defStyle) {
        this(context, attrs, defStyle, null, 0);
    }


    public BadgeView(Context context, AttributeSet attrs, int defStyle,
            View target, int tabIndex) {
        super(context, attrs, defStyle);
        init(context, target, tabIndex);
    }


    private void init(Context context, View target, int tabIndex) {


        this.context = context;
        this.target = target;
        this.targetTabIndex = tabIndex;


        // apply defaults
        badgePosition = DEFAULT_POSITION;
        badgeMargin = dipToPixels(DEFAULT_MARGIN_DIP);
        MARGIN_LEFT = dipToPixels(DEFAULT_MARGIN_DIP);
        MARGIN_TOP = dipToPixels(DEFAULT_MARGIN_DIP);
        MARGIN_RIGHT = dipToPixels(DEFAULT_MARGIN_DIP);
        MARGIN_BOTTOM = dipToPixels(DEFAULT_MARGIN_DIP);


        badgeColor = DEFAULT_BADGE_COLOR;


// setTypeface(Typeface.DEFAULT_BOLD);
// int paddingPixels = dipToPixels(DEFAULT_LR_PADDING_DIP);
// setPadding(paddingPixels, 0, paddingPixels, 0);
// setTextColor(DEFAULT_TEXT_COLOR);


        fadeIn = new AlphaAnimation(0, 1);
        fadeIn.setInterpolator(new DecelerateInterpolator());
        fadeIn.setDuration(200);
        fadeOut = new AlphaAnimation(1, 0);
        fadeOut.setInterpolator(new AccelerateInterpolator());
        fadeOut.setDuration(200);


        isShown = false;


        if (this.target != null) {
            applyTo(this.target);
        } else {
            show();
        }


    }


    private void applyTo(View target) {


        LayoutParams lp = target.getLayoutParams();
        ViewParent parent = target.getParent();


        FrameLayout container = new FrameLayout(context);


        if (target instanceof TabWidget) {


            // set target to the relevant tab child container
            target = ((TabWidget) target).getChildTabViewAt(targetTabIndex);
            this.target = target;


            ((ViewGroup) target).addView(container, new LayoutParams(
                    LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));


            this.setVisibility(View.GONE);
            container.addView(this);


        } else {


            // TODO verify that parent is indeed a ViewGroup
            ViewGroup group = (ViewGroup) parent;
            int index = group.indexOfChild(target);


            group.removeView(target);
            group.addView(container, index, lp);


            container.addView(target);


            this.setVisibility(View.GONE);
            container.addView(this);


            group.invalidate();


        }


    }


    public void show() {
        show(false, null);
    }


    public void show(boolean animate) {
        show(animate, fadeIn);
    }


    public void show(Animation anim) {
        show(true, anim);
    }


    public void hide() {
        hide(false, null);
    }


    public void hide(boolean animate) {
        hide(animate, fadeOut);
    }


    public void hide(Animation anim) {
        hide(true, anim);
    }


    public void toggle() {
        toggle(false, null, null);
    }


    public void toggle(boolean animate) {
        toggle(animate, fadeIn, fadeOut);
    }


    public void toggle(Animation animIn, Animation animOut) {
        toggle(true, animIn, animOut);
    }


    private void show(boolean animate, Animation anim) {
        if (getBackground() == null) {
            if (badgeBg == null) {
                badgeBg = getDefaultBackground();
            }
            setBackgroundDrawable(badgeBg);
        }
        applyLayoutParams();


        if (animate) {
            this.startAnimation(anim);
        }
        this.setVisibility(View.VISIBLE);
        isShown = true;
    }


    private void hide(boolean animate, Animation anim) {
        this.setVisibility(View.GONE);
        if (animate) {
            this.startAnimation(anim);
        }
        isShown = false;
    }


    private void toggle(boolean animate, Animation animIn, Animation animOut) {
        if (isShown) {
            hide(animate && (animOut != null), animOut);
        } else {
            show(animate && (animIn != null), animIn);
        }
    }


    /*public int increment(int offset) {
        CharSequence txt = getText();
        int i;
        if (txt != null) {
            try {
                i = Integer.parseInt(txt.toString());
            } catch (NumberFormatException e) {
                i = 0;
            }
        } else {
            i = 0;
        }
        i = i + offset;
        setText(String.valueOf(i));
        return i;
    }*/


    /*public int decrement(int offset) {
        return increment(-offset);
    }*/


    private ShapeDrawable getDefaultBackground() {


        int r = dipToPixels(DEFAULT_CORNER_RADIUS_DIP);
        float[] outerR = new float[] { r, r, r, r, r, r, r, r };


        RoundRectShape rr = new RoundRectShape(outerR, null, null);
        ShapeDrawable drawable = new ShapeDrawable(rr);
        drawable.getPaint().setColor(badgeColor);


        return drawable;


    }


    private void applyLayoutParams() {


        FrameLayout.LayoutParams lp = new FrameLayout.LayoutParams(
                LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);


        switch (badgePosition) {
        case POSITION_TOP_LEFT:
            lp.gravity = Gravity.LEFT | Gravity.TOP;
            lp.setMargins(MARGIN_LEFT, MARGIN_TOP, 0, 0);
            break;
        case POSITION_TOP_RIGHT:
            lp.gravity = Gravity.RIGHT | Gravity.TOP;
            lp.setMargins(0, MARGIN_TOP, MARGIN_RIGHT, 0);
            break;
        case POSITION_BOTTOM_LEFT:
            lp.gravity = Gravity.LEFT | Gravity.BOTTOM;
            lp.setMargins(MARGIN_LEFT, 0, 0, MARGIN_BOTTOM);
            break;
        case POSITION_BOTTOM_RIGHT:
            lp.gravity = Gravity.RIGHT | Gravity.BOTTOM;
            lp.setMargins(0, 0, MARGIN_RIGHT, MARGIN_BOTTOM);
            break;
        default:
            break;
        }


        setLayoutParams(lp);


    }


    public View getTarget() {
        return target;
    }


    @Override
    public boolean isShown() {
        return isShown;
    }


    public int getBadgePosition() {
        return badgePosition;
    }


    public void setBadgePosition(int layoutPosition) {
        this.badgePosition = layoutPosition;
    }


    public int getBadgeMargin() {
        return badgeMargin;
    }


    public void setBadgeMargin(int badgeMargin) {
        this.badgeMargin = dipToPixels(badgeMargin);
    }


    public void setBadgeMargin(int badgeMarginLeft, int badgeMarginTop, int badgeMarginRight, int badgeMarginBottom) {
        this.MARGIN_LEFT = dipToPixels(badgeMarginLeft);
        this.MARGIN_TOP = dipToPixels(badgeMarginTop);
        this.MARGIN_RIGHT = dipToPixels(badgeMarginRight);
        this.MARGIN_BOTTOM = dipToPixels(badgeMarginBottom);
    }


    public int getBadgeBackgroundColor() {
        return badgeColor;
    }


    public void setBadgeBackgroundColor(int badgeColor) {
        this.badgeColor = badgeColor;
        badgeBg = getDefaultBackground();
    }


    private int dipToPixels(int dip) {
        Resources r = getResources();
        float px = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dip,
                r.getDisplayMetrics());
        return (int) px;
    }

}

2、对应的调用

        mBadge = new BadgeView(this, personTab);
        mBadge.setBackgroundResource(R.drawable.coolyou_info_tip);
        mBadge.setBadgeMargin(0, 8, 13, 0);

mBadge .show()