看了都会喜欢的：loading效果

介绍：
一个不错的loading加载效果，弹性收缩，效果不错，学习android动画的朋友可以下载来研究研究
本例子其实由SeekBar实现，由MetaballView，MetaballDebugView实现动画效果.
项目来自:http://www.itlanbao.com/code/20151209/10000/100683.html

当滑动到有一个位置的时候设置选中和未选中状态.
metaballView.setPaintMode();

debugMetaballView.setPaintMode();
设置SeekBar 的进度debugMetaballView.setMaxDistance(progress);

效果截图：

布局引入：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#001d30"
    android:clipChildren="false"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity">

    <com.dodola.animview.MetaballView
        android:id="@+id/metaball"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true" />

    <com.dodola.animview.MetaballDebugView
        android:id="@+id/debug_metaball"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignEnd="@+id/metaball"
        android:layout_alignRight="@+id/metaball"
        android:layout_below="@+id/metaball"
        android:layout_marginTop="20dp" />

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_alignTop="@+id/debug_metaball"
        android:text="Debug test"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:textColor="@android:color/white" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:clickable="true"
        android:orientation="vertical">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="最大间距"
            android:textColor="@android:color/white" />

        <SeekBar
            android:id="@+id/seekBar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:max="400" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="贝塞尔曲线角度"
            android:textColor="@android:color/white" />

        <SeekBar
            android:id="@+id/seekBar2"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:max="200" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="贝塞尔曲线控制点长度比率"
            android:textColor="@android:color/white" />

        <SeekBar
            android:id="@+id/seekBar3"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:max="500" />
    </LinearLayout>
</RelativeLayout>




主要代码如下：
package com.dodola.animview;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ProgressBar;
import android.widget.SeekBar;

public class MainActivity extends AppCompatActivity implements SeekBar.OnSeekBarChangeListener {

    private MetaballView metaballView;
    private MetaballDebugView debugMetaballView;
    private SeekBar seekBar, seekBar2, seekBar3;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        metaballView = (MetaballView) this.findViewById(R.id.metaball);
        debugMetaballView = (MetaballDebugView) findViewById(R.id.debug_metaball);
        seekBar = (SeekBar) findViewById(R.id.seekBar);
        seekBar2 = (SeekBar) findViewById(R.id.seekBar2);
        seekBar3 = (SeekBar) findViewById(R.id.seekBar3);
        seekBar.setOnSeekBarChangeListener(this);
        seekBar2.setOnSeekBarChangeListener(this);
        seekBar3.setOnSeekBarChangeListener(this);

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_fill) {
            metaballView.setPaintMode(1);
            debugMetaballView.setPaintMode(1);
            return true;
        } else if (id == R.id.action_strock) {
            metaballView.setPaintMode(0);
            debugMetaballView.setPaintMode(0);
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @Override
    public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
        switch (seekBar.getId()) {
            case R.id.seekBar:
                debugMetaballView.setMaxDistance(progress);
                break;
            case R.id.seekBar2:
                debugMetaballView.setMv(progress / 100f);
                break;
            case R.id.seekBar3:
                debugMetaballView.setHandleLenRate(progress / 100f);
                break;
        }

    }

    @Override
    public void onStartTrackingTouch(SeekBar seekBar) {

    }

    @Override
    public void onStopTrackingTouch(SeekBar seekBar) {

    }
}