RLScrollView.java

/**
 * Copyright (c) 2013-2014, Rinc Liu (http://rincliu.com).
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.rincliu.library.widget;

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

public class RLScrollView extends ScrollView {

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

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

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

    public interface OnScrollChangedListener {
        public void onScrollChanged(int x, int y, int oldxX, int oldY);
    }

    private OnScrollChangedListener onScrollChangedListener;

    /**
     * @param onScrollChangedListener
     */
    public void setOnScrollListener(OnScrollChangedListener onScrollChangedListener) {
        this.onScrollChangedListener = onScrollChangedListener;
    }

    @Override
    protected void onScrollChanged(int x, int y, int oldX, int oldY) {
        super.onScrollChanged(x, y, oldX, oldY);
        if (onScrollChangedListener != null) {
            onScrollChangedListener.onScrollChanged(x, y, oldX, oldY);
        }
    }

    /**
     * @param child
     * @return
     */
    public boolean isChildVisible(View child) {
        if (child == null) {
            return false;
        }
        Rect scrollBounds = new Rect();
        getHitRect(scrollBounds);
        return child.getLocalVisibleRect(scrollBounds);
    }

    /**
     * @return
     */
    public boolean isAtTop() {
        return getScrollY() <= 0;
    }

    @Deprecated
    public boolean isAtBottom() {
        return getChildAt(getChildCount() - 1).getBottom() + getPaddingBottom() == getHeight() + getScrollY();
    }
}