/**

 * 解决webView键盘遮挡问题的类

 * Created by zqy on 2016/11/14.

 */

public class KeyBoardListener {

    private Activity activity;

// private Handler mhanHandler;

    private View mChildOfContent;

    private int usableHeightPrevious;

    private FrameLayout.LayoutParams frameLayoutParams;

    private static KeyBoardListener keyBoardListener;

    public static KeyBoardListener getInstance(Activity activity) {

// if(keyBoardListener==null){

        keyBoardListener=new KeyBoardListener(activity);

// }

        return keyBoardListener;

    }

    public KeyBoardListener(Activity activity) {

        super();

// TODO Auto-generated constructor stub

        this.activity = activity;

// this.mhanHandler = handler;

    }

    public void init() {

        FrameLayout content = (FrameLayout) activity

                .findViewById(android.R.id.content);

        mChildOfContent = content.getChildAt(0);

        mChildOfContent.getViewTreeObserver().addOnGlobalLayoutListener(

                new ViewTreeObserver.OnGlobalLayoutListener() {

                    public void onGlobalLayout() {

                        possiblyResizeChildOfContent();

                    }

                });

        frameLayoutParams = (FrameLayout.LayoutParams) mChildOfContent

                .getLayoutParams();

    }

    private void possiblyResizeChildOfContent() {

        int usableHeightNow = computeUsableHeight();

        if (usableHeightNow != usableHeightPrevious) {

            int usableHeightSansKeyboard = mChildOfContent.getRootView()

                    .getHeight();

            int heightDifference = usableHeightSansKeyboard - usableHeightNow;

            if (heightDifference > (usableHeightSansKeyboard / 4)) {

// keyboard probably just became visible

                frameLayoutParams.height = usableHeightSansKeyboard

                        - heightDifference;

            } else {

// keyboard probably just became hidden

                frameLayoutParams.height = usableHeightSansKeyboard;

            }

            mChildOfContent.requestLayout();

            usableHeightPrevious = usableHeightNow;

        }

    }

    private int computeUsableHeight() {

        Rect r = new Rect();

        mChildOfContent.getWindowVisibleDisplayFrame(r);

        return (r.bottom - r.top);

    }

// private void showLog(String title, String msg) {

// Log.d("Unity", title + "------------>" + msg);

// }

}