Android 自定义 ClearEditTextView

ClearEditTextView通过扩展EditText，添加了右边清除按钮、输入数据不合法时可左右抖动的功能。效果如下：

整体的实现代码如下：

public class ClearEditTextView extends EditText implements View.OnFocusChangeListener, TextWatcher {

    //右边的删除按钮
    private Drawable mClearDrawable;

    public ClearEditTextView(Context context) {
        this(context, null);
    }

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

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

    private void init() {
        mClearDrawable = getResources().getDrawable(R.drawable.clear);
        //设置删除按钮的边界
        mClearDrawable.setBounds(0, 0, mClearDrawable.getIntrinsicWidth(), mClearDrawable.getIntrinsicHeight());
        //默认隐藏删除按钮
        setClearIcon(false);

        //监听EditText焦点变化，以根据text长度控制删除按钮的显示、隐藏
        setOnFocusChangeListener(this);
        //监听文本内容变化
        addTextChangedListener(this);
    }

    /**
     * 控制EditText右边制删除按钮的显示、隐藏
     */
    private void setClearIcon(boolean isShow) {
        Drawable rightDrawable = isShow ? mClearDrawable : null;
        setCompoundDrawables(getCompoundDrawables()[0], getCompoundDrawables()[1],
                rightDrawable, getCompoundDrawables()[3]);
    }

    /**
     * 有焦点，并文本长度大于0则显示删除按钮
     *
     * @param v
     * @param hasFocus
     */
    @Override
    public void onFocusChange(View v, boolean hasFocus) {
        if (hasFocus) {
            setClearIcon(getText().length() > 0);
        } else {
            setClearIcon(false);
        }
    }

    /**
     * 文本内容变化时回调
     * 当文本长度大于0时显示删除按钮， 否则隐藏
     *
     * @param text
     * @param start
     * @param lengthBefore
     * @param lengthAfter
     */
    @Override
    public void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) {
        super.onTextChanged(text, start, lengthBefore, lengthAfter);
        setClearIcon(text.length() > 0);
    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {

    }

    @Override
    public void afterTextChanged(Editable s) {

    }

    /**
     * 通过手指的触摸位置模式删除按钮的点击事件
     *
     * @param event
     * @return
     */
    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if (getCompoundDrawables()[2] != null) {
            if (event.getAction() == MotionEvent.ACTION_UP) {
                boolean xTouchable = event.getX() > (getWidth() - getPaddingRight() - mClearDrawable.getIntrinsicWidth())
                        && (event.getX() < (getWidth() - getPaddingRight()));

                boolean yTouchable = event.getY() > (getHeight() - mClearDrawable.getIntrinsicHeight()) / 2
                        && event.getY() < (getHeight() + mClearDrawable.getIntrinsicHeight()) / 2;

                //清除文本
                if (xTouchable && yTouchable) {
                    setText("");
                }
            }
        }
        return super.onTouchEvent(event);
    }


    /**
     * EditText抖动
     *
     * @param counts
     * @return
     */
    public void startShake(int counts) {
        Animation translateAnimation = new TranslateAnimation(0, 10, 0, 0);
        translateAnimation.setInterpolator(new CycleInterpolator(counts));
        translateAnimation.setDuration(500);
        startAnimation(translateAnimation);
    }
}

大致说一下流程，首先给EditText添加addTextChangedListener来监听输入文本的变化，如果EditText有焦点并文本长度大于0则将EditText的drawableRight设置为删除的图片否则设置为空：

@Override
    public void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) {
        super.onTextChanged(text, start, lengthBefore, lengthAfter);
        setClearIcon(text.length() > 0);
    }

private void setClearIcon(boolean isShow) {
        Drawable rightDrawable = isShow ? mClearDrawable : null;
        setCompoundDrawables(getCompoundDrawables()[0], getCompoundDrawables()[1],
                rightDrawable, getCompoundDrawables()[3]);
    }

这样删除按钮就添加好了。由于不能直接给添加的删除按钮绑定点击事件，所以可以考虑通过重写EditText的onTouchEvent方法，如果手指的触摸x、y坐标在删除图片上则执行删除操作：

@Override
    public boolean onTouchEvent(MotionEvent event) {
        if (getCompoundDrawables()[2] != null) {
            if (event.getAction() == MotionEvent.ACTION_UP) {
                boolean xTouchable = event.getX() > (getWidth() - getPaddingRight() - mClearDrawable.getIntrinsicWidth())
                        && (event.getX() < (getWidth() - getPaddingRight()));

                boolean yTouchable = event.getY() > (getHeight() - mClearDrawable.getIntrinsicHeight()) / 2
                        && event.getY() < (getHeight() + mClearDrawable.getIntrinsicHeight()) / 2;

                //清除文本
                if (xTouchable && yTouchable) {
                    setText("");
                }
            }
        }
        return super.onTouchEvent(event);
    }

到这里删除按钮的逻辑就完成了。关于左右抖动的效果就是给EditText设置一个左右移动的动画：

public void startShake(int counts) {
        Animation translateAnimation = new TranslateAnimation(0, 10, 0, 0);
        translateAnimation.setInterpolator(new CycleInterpolator(counts));
        translateAnimation.setDuration(500);
        startAnimation(translateAnimation);
    }

到这里一个简单的EditText扩展就实现了。

关于倒计时的功能可通过CountDownTimer类方便的实现：

mCountDownTimer = new CountDownTimer(long millisInFuture, long countDownInterval) {
            @Override
            public void onTick(long millisUntilFinished) {
               //倒计时进行中
            }

            @Override
            public void onFinish() {
               //倒计时结束
            }
        }

参数millisInFuture代表倒计时的总时长，countDownInterval代表时间间隔，单位都是毫秒。通过CountDownTimer类的start()和cancel()方法可以开始和结束倒计时。

demo下载...