FullScrollNotClearFocusScrollView

package com.personal.lqg;

import android.content.Context;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.View;
import android.widget.ScrollView;

import java.util.List;

/**
 * Created by LeeQianguo on 14-10-08.
 */
public class FullScrollNotClearFocusScrollView extends ScrollView {

    private final Rect mTempRect = new Rect();

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

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

    public FullScrollNotClearFocusScrollView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    public boolean fullScroll(int direction) {
        boolean down = direction == View.FOCUS_DOWN;
        int height = getHeight();

        mTempRect.top = 0;
        mTempRect.bottom = height;

        if (down) {
            int count = getChildCount();
            if (count > 0) {
                View view = getChildAt(count - 1);
                mTempRect.bottom = view.getBottom() + getPaddingBottom();
                mTempRect.top = mTempRect.bottom - height;
            }
        }

        return scrollAndFocus(direction, mTempRect.top, mTempRect.bottom);
    }

    private boolean scrollAndFocus(int direction, int top, int bottom) {
        boolean handled = true;

        int height = getHeight();
        int containerTop = getScrollY();
        int containerBottom = containerTop + height;
        boolean up = direction == View.FOCUS_UP;

        if (top >= containerTop && bottom <= containerBottom) {
            handled = false;
        } else {
            int delta = up ? (top - containerTop) : (bottom - containerBottom);
            doScrollY(delta);
        }

        return handled;
    }

    private void doScrollY(int delta) {
        if (delta != 0) {
            if (isSmoothScrollingEnabled()) {
                smoothScrollBy(0, delta);
            } else {
                scrollBy(0, delta);
            }
        }
    }
}