开源库 bouncyEditText解析

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运行效果

如何使用？
在布局XML里引用即可，如下：

 <com.mingle.BouncyEditText
       android:layout_width="fill_parent"
       android:hint="账号"
       android:text="255"
       android:layout_height="wrap_content">
       </com.mingle.BouncyEditText>

跟别的自定义控件一样操作。
只需要在项目包里复制内贴BouncyEditText这个类和对应的一些资源文件即可，也可以Library相应的LIB包。

我们来读下核心类：

public class BouncyEditText extends EditText {

    private int hintColor=getResources().getColor(R.color.hint_color);
    private Paint paint;
    private Status status= Status.ANIMATION_NONE;
    private String hintText;
    private Interpolator animOutInterpolator;
    private Interpolator animInInterpolator;

    private float animInDuration=200.0f;
    private float animOutDuration=260.0f;

    private boolean isSetPadding=false;
    private boolean isHasHint = false;

    public BouncyEditText(Context context) {
        super(context);
    }

    public BouncyEditText(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public BouncyEditText(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);

        init();
    }

    private void init() {
        paint=new Paint();
        //初始化一些动画效果
        animOutInterpolator = new OvershootInterpolator(1.3f);
        animInInterpolator = new DecelerateInterpolator();

        if(getHint()!=null) {
            isHasHint =true;
            hintText = getHint().toString();
            setHint("");
        }
//        if (!TextUtils.isEmpty(getText().toString())) {
//            status = Status.ANIMATION_OUT;
//
//        } else {
//            status = Status.ANIMATION_IN;
//        }

    }
    //版本兼容
    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public BouncyEditText(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        init();
    }

    long startTime;

    private String preString;
    //继承textview重写的方法
    @Override
    protected void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) {
        super.onTextChanged(text, start, lengthBefore, lengthAfter);
        if(!isHasHint){
            return;
        }

        if(TextUtils.isEmpty(preString) != TextUtils.isEmpty( getText().toString())) {

            if (!TextUtils.isEmpty(getText().toString())) {
                status = Status.ANIMATION_OUT;

            } else {
                status = Status.ANIMATION_IN;
            }

            preString = (String) getText().toString();
            startTime = System.currentTimeMillis();
        }
    }

    @Override
    public void setText(CharSequence text, BufferType type) {
        super.setText(text, type);

        if(TextUtils.isEmpty(text)){
            text="";
        }
        preString= (String) text;

    }

    public void setHintText(String hintText) {
        this.hintText = hintText;

        isHasHint =true;
        this.hintText = hintText;
        setHint("");

    }
        //具体的画一些效果啊，动作什么的，我们用就行了。
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        if(!isHasHint){
            return;
        }
        paint.set(getPaint());
        paint.setAntiAlias(true);
        paint.setColor(hintColor) ;

        if(!isSetPadding) {
            setPadding(getPaddingLeft(), getPaddingTop(), getPaddingRight() + (int) paint.measureText(hintText), getPaddingBottom());
            isSetPadding=true;
        }

        float maxHintY = getBaseline();
        switch (status){
            case  ANIMATION_IN:

                if(System.currentTimeMillis()-startTime<animInDuration
                        ){
                    float hintX=getCompoundPaddingLeft() + getScrollX()+(getWidth()-getCompoundPaddingRight()-getCompoundPaddingLeft())*(1- animInInterpolator.getInterpolation((System.currentTimeMillis()-startTime)/animInDuration));

                    canvas.drawText(hintText,hintX,maxHintY,paint);
                    postInvalidate();
                }else{
                    float hintX = getCompoundPaddingLeft();
                    canvas.drawText(hintText, hintX, maxHintY, paint);
                }

                break;
            case  ANIMATION_OUT:

                if(System.currentTimeMillis()-startTime<animOutDuration
                        ){
                    float hintX=getCompoundPaddingLeft() + getScrollX()+(getWidth()-getCompoundPaddingRight()-getCompoundPaddingLeft())* animOutInterpolator.getInterpolation((System.currentTimeMillis()-startTime)/animOutDuration);
                    canvas.drawText(hintText,hintX,maxHintY,paint);
                    postInvalidate();
                }else{
                    float hintX=
                            getScrollX()+(getWidth()-getCompoundPaddingRight());
                    canvas.drawText(hintText, hintX, maxHintY, paint);
                }

                break;
            case  ANIMATION_NONE:

                if(getText().toString().length()==0){
                    float hintX = getCompoundPaddingLeft() + getScrollX();
                    canvas.drawText(hintText,hintX,maxHintY,paint);

                }else{
                    float hintX=
                            getScrollX()+(getWidth()-getCompoundPaddingRight());
                    canvas.drawText(hintText,hintX,maxHintY,paint);
                }

                break;
        }

    }
    public enum  Status{
        ANIMATION_IN,
        ANIMATION_NONE,
        ANIMATION_OUT
    }
}

color.xml

<resources>

    <color name="hint_color">#9e9e9e</color>
</resources>

当然如果是伸手党，就更简单，复制上面的一堆，然后用就行了。很简单，效果也不错。

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