PullToRefreshScrollView.java

package com.saikali.android_skwissh.widgets.pulltorefresh;

import android.annotation.TargetApi;
import android.content.Context;
import android.os.Build.VERSION;
import android.os.Build.VERSION_CODES;
import android.util.AttributeSet;
import android.view.View;
import android.widget.ScrollView;

import com.saikali.android_skwissh.R;

public class PullToRefreshScrollView extends PullToRefreshBase<ScrollView> {

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

	@Override
	protected ScrollView createRefreshableView(Context context, AttributeSet attrs) {
		ScrollView scrollView;
		if (VERSION.SDK_INT >= VERSION_CODES.GINGERBREAD) {
			scrollView = new InternalScrollViewSDK9(context, attrs);
		} else {
			scrollView = new ScrollView(context, attrs);
		}

		scrollView.setId(R.id.scrollview);
		return scrollView;
	}

	@Override
	protected boolean isReadyForPullDown() {
		return this.mRefreshableView.getScrollY() == 0;
	}

	@Override
	protected boolean isReadyForPullUp() {
		View scrollViewChild = this.mRefreshableView.getChildAt(0);
		if (null != scrollViewChild)
			return this.mRefreshableView.getScrollY() >= (scrollViewChild.getHeight() - this.getHeight());
		return false;
	}

	@TargetApi(9)
	final class InternalScrollViewSDK9 extends ScrollView {

		public InternalScrollViewSDK9(Context context, AttributeSet attrs) {
			super(context, attrs);
		}

		@Override
		protected boolean overScrollBy(int deltaX, int deltaY, int scrollX, int scrollY, int scrollRangeX, int scrollRangeY, int maxOverScrollX, int maxOverScrollY, boolean isTouchEvent) {

			final boolean returnValue = super.overScrollBy(deltaX, deltaY, scrollX, scrollY, scrollRangeX, scrollRangeY, maxOverScrollX, maxOverScrollY, isTouchEvent);

			// Does all of the hard work...
			OverscrollHelper.overScrollBy(PullToRefreshScrollView.this, deltaY, scrollY, this.getScrollRange(), isTouchEvent);

			return returnValue;
		}

		/**
		 * Taken from the AOSP ScrollView source
		 */
		private int getScrollRange() {
			int scrollRange = 0;
			if (this.getChildCount() > 0) {
				View child = this.getChildAt(0);
				scrollRange = Math.max(0, child.getHeight() - (this.getHeight() - this.getPaddingBottom() - this.getPaddingTop()));
			}
			return scrollRange;
		}
	}
}