android-android 带删除功能的EditText

/**
 * Created by xp.chen on 2016/11/25.
 */

public class DJEditText extends AppCompatEditText {


    private static final int DRAWABLE_LEFT = 0;
    private static final int DRAWABLE_TOP = 1;
    private static final int DRAWABLE_RIGHT = 2;
    private static final int DRAWABLE_BOTTOM = 3;
    private Drawable mClearDrawable;



    public DJEditText(Context context) {
        super(context);
        init();
    }

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

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



    private void init() {
        mClearDrawable = getResources().getDrawable(R.drawable.app_clear_btn_bg_selector);
    }


    @Override
    protected void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) {
        super.onTextChanged(text, start, lengthBefore, lengthAfter);
        setClearIconVisible(hasFocus() && length() > 0);
    }

    @Override
    protected void onFocusChanged(boolean focused, int direction, Rect previouslyFocusedRect) {
        super.onFocusChanged(focused, direction, previouslyFocusedRect);
        setClearIconVisible(focused && length() > 0);
    }


    @Override
    public boolean onTouchEvent(MotionEvent event) {
        switch (event.getAction()) {
            case MotionEvent.ACTION_UP:
                Drawable drawable = getCompoundDrawables()[DRAWABLE_RIGHT];
                if (drawable != null && event.getX() <= (getWidth() - getPaddingRight()) && event.getX() >= (getWidth() - getPaddingRight() - drawable.getBounds().width())) {
                    setText("");
                }
                break;
            default:
                break;
        }
        return super.onTouchEvent(event);
    }


    public void setClearIconVisible(boolean visible) {
        setCompoundDrawablesWithIntrinsicBounds(getCompoundDrawables()[DRAWABLE_LEFT], getCompoundDrawables()[DRAWABLE_TOP]
                ,visible ? mClearDrawable : null, getCompoundDrawables()[DRAWABLE_BOTTOM]);
    }
}