Android输入框的联动控制

/** 
* 对一些含有两个输入框和一个确认按钮的页面，比如登录注册页面，一般是一个账号输入框、一个密码输入框、以及一个确认按钮。
* 点击第二个输入框弹出键盘时，键盘常常会把确认按钮给遮挡住，这时，我们常常要求将确认按钮框上移至输入框之上，以避免遮挡确认按钮。
* 下面三个类即实现了此种功能，代码独立，用法简单快捷
*
* 1. 一个输入框时：

* new SoftInputOneEdtCtrl(your FragmentActivity).register(View viewBaseline, View viewToMove, EditText editText);

* 2. 两个输入框时：
* new SoftInputTwoEdtCtrl(your FragmentActivity).register(View viewBaseline, View viewToMove, EditText edt1, EditText edit2);

*/

import android.graphics.Rect;
import android.os.Handler;
import android.support.v4.app.FragmentActivity;
import android.view.View;
import android.view.View.OnLayoutChangeListener;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
import android.widget.EditText;


public abstract class SoftInputCtrlAbs
        implements OnLayoutChangeListener, OnGlobalLayoutListener, Runnable {

    protected FragmentActivity mActivity;

    private volatile int mNewBottom;
    private volatile int mOldBottom;

    protected View mViewBaseline;
    protected View mViewToMove;

    protected volatile boolean mHasMovedUp = false;

    private Handler mHandler = new Handler();

    public SoftInputCtrlAbs(FragmentActivity activity) {
        mActivity = activity;
        View rootView = mActivity.getWindow().findViewById(android.R.id.content);
        rootView.addOnLayoutChangeListener(this);
        rootView.getViewTreeObserver().addOnGlobalLayoutListener(this);
    }

    public void register(View viewBaseline, View viewToMove, EditText... editTexts) {
        mViewToMove = viewToMove;
        mViewBaseline = viewBaseline;
    }

    public void unregister() {
        if (mActivity != null) {
            View rootView = mActivity.getWindow().findViewById(android.R.id.content);
            rootView.removeOnLayoutChangeListener(this);
            rootView.getViewTreeObserver().removeGlobalOnLayoutListener(this);
        }
        reset();
    }

    public void postMove() {
        if (mHandler != null) {
            mHandler.post(this);
        }
    }

    @Override
    public void run() {
        moveUp();
    }

    @Override
    public void onLayoutChange(View v, int left, int top, int right, int bottom, int oldLeft,
            int oldTop, int oldRight, int oldBottom) {
        mNewBottom = bottom;
        mOldBottom = oldBottom;
    }

    public int getNewBottom() {
        return mNewBottom;
    }

    public int getOldBottom() {
        return mOldBottom;
    }

    protected synchronized void moveUp() {
        if (mViewToMove == null || mViewBaseline == null) return;
        int[] locationViewBaseline = new int[2];
        mViewBaseline.getLocationOnScreen(locationViewBaseline);
        int[] locationViewToMove = new int[2];
        mViewToMove.getLocationOnScreen(locationViewToMove);
        Rect rectViewToMove = new Rect();
        mViewToMove.getGlobalVisibleRect(rectViewToMove);

        int moveTopDistance = rectViewToMove.bottom - locationViewBaseline[1] - mViewBaseline
                .getHeight();

        if (moveTopDistance > 0 || mHasMovedUp) return;
        if (moveTopDistance < 0) {
            mHasMovedUp = true;
        }
        mViewToMove.setPadding(mViewToMove.getPaddingLeft(), moveTopDistance,
                mViewToMove.getPaddingRight(), mViewToMove.getPaddingBottom());
    }

    public void reset() {
        mViewToMove = null;
        mViewBaseline = null;
        mNewBottom = 0;
        mOldBottom = 0;
        mHasMovedUp = false;
        mActivity = null;
    }

    public void resetPosition () {
        if (mViewToMove != null) {
            mViewToMove.setPadding(mViewToMove.getPaddingLeft(), 0, mViewToMove.getPaddingRight(),
                    mViewToMove.getPaddingBottom());
            mHasMovedUp = false;
        }
    }
}

import android.support.v4.app.FragmentActivity;
import android.view.View;
import android.widget.EditText;

public class SoftInputOneEdtCtrl extends SoftInputCtrlAbs {

    public SoftInputOneEdtCtrl(FragmentActivity activity) {
        super(activity);
    }

    @Override
    public void register(View viewBaseline, View viewToMove, EditText... editTexts) {
        super.register(viewBaseline, viewToMove, editTexts);
    }

    @Override
    public void unregister() {
        super.unregister();
    }

    @Override
    public void onGlobalLayout() {
        int bottom = getNewBottom();
        int oldBottom = getOldBottom();

        if (bottom < oldBottom) {
            postMove();
        } else if (bottom > oldBottom) {
            resetPosition();
        }
    }
}

import android.support.v4.app.FragmentActivity;
import android.view.KeyEvent;
import android.view.View;
import android.view.View.OnFocusChangeListener;
import android.view.inputmethod.EditorInfo;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.TextView.OnEditorActionListener;


public class SoftInputTwoEdtCtrl extends SoftInputCtrlAbs{

    private static String TAG = "SoftInputTwoEdtCtrl";

    private EditText mEdtFirst;
    private EditText mEdtSecond;

    private boolean mEdtActionNext = false;
    private boolean mEdtSecondHasFocus = false;

    private OnEditorActionListener mOnEditorActionListener = new OnEditorActionListener() {
        @Override
        public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
            if (actionId == EditorInfo.IME_ACTION_NEXT) {
                performActionNextEdtFirst();
            }
            return false;
        }
    };

    public SoftInputTwoEdtCtrl(FragmentActivity activity) {
        super(activity);
    }

    private synchronized void performActionNextEdtFirst() {
        mEdtActionNext = true;
        postMove();
    }

    @Override
    public void register(View viewBaseline, View viewToMove, EditText... editTexts) {
        super.register(viewBaseline, viewToMove, editTexts);
        if ( editTexts == null|| editTexts.length != 2) return;
        mEdtFirst = editTexts[0];
        mEdtSecond = editTexts[1];
        mEdtActionNext = false;
        mEdtSecondHasFocus = false;

        mEdtSecond.setOnFocusChangeListener(new OnFocusChangeListener() {
            @Override
            public void onFocusChange(View v, boolean hasFocus) {
                mEdtSecondHasFocus = hasFocus;
                postMove();
            }
        });
        mEdtFirst.setOnEditorActionListener(mOnEditorActionListener);
    }

    @Override
    public void onGlobalLayout() {
        int bottom = getNewBottom();
        int oldBottom = getOldBottom();

        if (bottom < oldBottom) {
            if (!mEdtSecondHasFocus) return;
            postMove();

        } else if (bottom > oldBottom) {
            resetPosition();

        } else if (mEdtActionNext && mEdtSecondHasFocus) {
            mEdtActionNext = false;
        }
    }

    @Override
    public void moveUp() {
        super.moveUp();
    }

    @Override
    public void reset() {
        super.reset();
        mEdtFirst = null;
        mEdtSecond = null;

        mEdtActionNext = false;
        mEdtSecondHasFocus = false;
    }
}