安卓自定义带图片的TextView标签组件

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:nono="http://com.demo0.nono"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context=".main">

    <com.demo0.nono.icontext.IconTextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        nono:iconSrc="@drawable/pic"
        android:text="smile"/>

    <com.demo0.nono.icontext.IconTextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        nono:iconSrc="@drawable/pic"
        android:textSize="24dp"
        android:text="smile 24 dp"/>

    <com.demo0.nono.icontext.IconTextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        nono:iconSrc="@drawable/pic"
        android:textSize="36dp"
        android:text="smile 36 dp"/>

    <com.demo0.nono.icontext.IconTextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        nono:iconSrc="@drawable/pic"
        android:textSize="50dp"
        android:text="smile 50 dp"/>
</LinearLayout>

package com.demo0.nono.icontext;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.widget.TextView;


/**
 * Created by nono on 2018/4/6.
 */
public class IconTextView extends TextView {
    private final String namespace = "http://com.demo0.nono";
    private int resourceId = 0;
    private Bitmap bitmap;
    public IconTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        resourceId = attrs.getAttributeResourceValue(namespace, "iconSrc", 0);
        if(resourceId>0) {
            bitmap = BitmapFactory.decodeResource(getResources(), resourceId);
        }
    }
    @Override
    protected void onDraw(Canvas canvas) {
        if(bitmap!=null) {
            Rect src = new Rect();
            Rect target = new Rect();
            src.left = 0;
            src.top = 0;
            src.right = bitmap.getWidth();
            src.bottom = bitmap.getHeight();
            target.top = 0;
            target.left = 0;
            target.bottom = getMeasuredHeight();
            int wid = (getMeasuredHeight()*bitmap.getWidth())/bitmap.getHeight();
            target.right = wid;
            canvas.drawBitmap(bitmap, src, target, getPaint());
            canvas.translate(wid,0);
        }
        super.onDraw(canvas);
    }

}