ListView touch listener for dismissing certain ListView items. Based on Roman Nurik & Niek Haarman's SwipeDismissListViewTouchListener. Depends on NineOldAndroids.

SelectiveSwipeDismissListViewTouchListener.java

import static com.nineoldandroids.view.ViewHelper.setAlpha;
import static com.nineoldandroids.view.ViewPropertyAnimator.animate;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import android.annotation.SuppressLint;
import android.graphics.Rect;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ListView;

import com.haarman.listviewanimations.itemmanipulation.OnDismissCallback;
import com.nineoldandroids.animation.Animator;
import com.nineoldandroids.animation.AnimatorListenerAdapter;
import com.nineoldandroids.animation.ValueAnimator;
import com.nineoldandroids.view.ViewHelper;

/**
 * A {@link android.view.View.OnTouchListener} that makes the list items in a
 * {@link ListView} dismissable. {@link ListView} is given special treatment
 * because by default it handles touches for its list items... i.e. it's in
 * charge of drawing the pressed state (the list selector), handling list item
 * clicks, etc.
 * 
 * <p>
 * Example usage:
 * </p>
 * 
 * <pre>
 * SwipeDismissListViewTouchListener touchListener = new SwipeDismissListViewTouchListener(
 * 		listView, new SwipeDismissListViewTouchListener.OnDismissCallback() {
 * 			public void onDismiss(ListView listView,
 * 					int[] reverseSortedPositions) {
 * 				for (int position : reverseSortedPositions) {
 * 					adapter.remove(adapter.getItem(position));
 * 				}
 * 				adapter.notifyDataSetChanged();
 * 			}
 * 		});
 * listView.setOnTouchListener(touchListener);
 * </pre>
 */
@SuppressLint("Recycle")
public class SelectiveSwipeDismissListViewTouchListener implements
		View.OnTouchListener {
    
  	public interface SelectiveSwipeDismissAdapter {
    		public boolean canDismissItem(int position);
  	}
  
	class PendingDismissData implements Comparable<PendingDismissData> {
		public int position;
		public View view;

		public PendingDismissData(int position, View view) {
			this.position = position;
			this.view = view;
		}

		@Override
		public int compareTo(PendingDismissData other) {
			// Sort by descending position
			return other.position - position;
		}
	}

	// Cached ViewConfiguration and system-wide constant values
	private int mSlop;
	private int mMinFlingVelocity;
	private int mMaxFlingVelocity;

	private long mAnimationTime;
	// Fixed properties
	private ListView mListView;
	private OnDismissCallback mCallback;

	private int mViewWidth = 1; // 1 and not 0 to prevent dividing by zero
	// Transient properties
	private List<PendingDismissData> mPendingDismisses = new ArrayList<PendingDismissData>();
	private int mDismissAnimationRefCount = 0;
	private float mDownX;
	private float mDownY;
	private boolean mSwiping;
	private VelocityTracker mVelocityTracker;
	private int mDownPosition;
	private View mDownView;
	private boolean mPaused;

	private SelectiveSwipeDismissAdapter mAdapter;

	/**
	 * Constructs a new swipe-to-dismiss touch listener for the given list view.
	 * 
	 * @param listView
	 *            The list view whose items should be dismissable.
	 * @param callback
	 *            The callback to trigger when the user has indicated that she
	 *            would like to dismiss one or more list items.
	 */
	public SelectiveSwipeDismissListViewTouchListener(ListView listView,
			SelectiveSwipeDismissAdapter adapter, OnDismissCallback callback) {
		ViewConfiguration vc = ViewConfiguration.get(listView.getContext());
		mSlop = vc.getScaledTouchSlop();
		mMinFlingVelocity = vc.getScaledMinimumFlingVelocity();
		mMaxFlingVelocity = vc.getScaledMaximumFlingVelocity();
		mAnimationTime = listView.getContext().getResources()
				.getInteger(android.R.integer.config_shortAnimTime);
		mListView = listView;
		mAdapter = adapter;
		mCallback = callback;
	}

	@Override
	public boolean onTouch(View view, MotionEvent motionEvent) {
		if (mViewWidth < 2) {
			mViewWidth = mListView.getWidth();
		}

		switch (motionEvent.getActionMasked()) {
		case MotionEvent.ACTION_DOWN: {
			if (mPaused) {
				return false;
			}

			// TODO: ensure this is a finger, and set a flag

			// Find the child view that was touched (perform a hit test)
			Rect rect = new Rect();
			int childCount = mListView.getChildCount();
			int[] listViewCoords = new int[2];
			mListView.getLocationOnScreen(listViewCoords);
			int x = (int) motionEvent.getRawX() - listViewCoords[0];
			int y = (int) motionEvent.getRawY() - listViewCoords[1];
			View child;
			for (int i = 0; i < childCount; i++) {
				child = mListView.getChildAt(i);
				child.getHitRect(rect);
				if (rect.contains(x, y)) {
					mDownView = child;
					break;
				}
			}

			if (mDownView != null) {
				mDownX = motionEvent.getRawX();
				mDownY = motionEvent.getRawY();
				mDownPosition = mListView.getPositionForView(mDownView);

				if (!mAdapter.canDismissItem(mDownPosition)) {
					return false;
				}

				mVelocityTracker = VelocityTracker.obtain();
				mVelocityTracker.addMovement(motionEvent);
			}
			view.onTouchEvent(motionEvent);
			return true;
		}

		case MotionEvent.ACTION_UP: {
			if (mVelocityTracker == null) {
				break;
			}

			float deltaX = motionEvent.getRawX() - mDownX;
			mVelocityTracker.addMovement(motionEvent);
			mVelocityTracker.computeCurrentVelocity(1000);
			float velocityX = Math.abs(mVelocityTracker.getXVelocity());
			float velocityY = Math.abs(mVelocityTracker.getYVelocity());
			boolean dismiss = false;
			boolean dismissRight = false;
			if (Math.abs(deltaX) > mViewWidth / 2) {
				dismiss = true;
				dismissRight = deltaX > 0;
			} else if (Math.abs(deltaX) > mViewWidth / 4
					&& mMinFlingVelocity <= velocityX
					&& velocityX <= mMaxFlingVelocity
					&& velocityY < velocityX / 2) {
				dismiss = true;
				dismissRight = mVelocityTracker.getXVelocity() > 0;
			}
			if (dismiss) {
				// dismiss
				final View downView = mDownView; // mDownView gets
													// null'd
													// before animation
													// ends
				final int downPosition = mDownPosition;
				++mDismissAnimationRefCount;
				animate(mDownView)
						.translationX(dismissRight ? mViewWidth : -mViewWidth)
						.alpha(0).setDuration(mAnimationTime)
						.setListener(new AnimatorListenerAdapter() {
							@Override
							public void onAnimationEnd(Animator animation) {
								performDismiss(downView, downPosition);
							}
						});
			} else {
				// cancel
				animate(mDownView).translationX(0).alpha(1)
						.setDuration(mAnimationTime).setListener(null);
			}
			mVelocityTracker = null;
			mDownX = 0;
			mDownView = null;
			mDownPosition = AdapterView.INVALID_POSITION;
			mSwiping = false;
			break;
		}

		case MotionEvent.ACTION_MOVE: {
			if (mVelocityTracker == null || mPaused) {
				break;
			}

			mVelocityTracker.addMovement(motionEvent);
			float deltaX = motionEvent.getRawX() - mDownX;
			float deltaY = motionEvent.getRawY() - mDownY;
			if (Math.abs(deltaX) > mSlop && Math.abs(deltaX) > Math.abs(deltaY)) {
				mSwiping = true;
				mListView.requestDisallowInterceptTouchEvent(true);

				// Cancel ListView's touch (un-highlighting the item)
				MotionEvent cancelEvent = MotionEvent.obtain(motionEvent);
				cancelEvent
						.setAction(MotionEvent.ACTION_CANCEL
								| (motionEvent.getActionIndex() << MotionEvent.ACTION_POINTER_INDEX_SHIFT));
				mListView.onTouchEvent(cancelEvent);
			}

			if (mSwiping) {
				ViewHelper.setTranslationX(mDownView, deltaX);
				setAlpha(
						mDownView,
						Math.max(
								0f,
								Math.min(1f, 1f - 2f * Math.abs(deltaX)
										/ mViewWidth)));
				return true;
			}
			break;
		}
		}
		return false;
	}

	private void performDismiss(final View dismissView,
			final int dismissPosition) {
		// Animate the dismissed list item to zero-height and fire the
		// dismiss
		// callback when
		// all dismissed list item animations have completed. This triggers
		// layout on each animation
		// frame; in the future we may want to do something smarter and more
		// performant.

		final ViewGroup.LayoutParams lp = dismissView.getLayoutParams();
		final int originalHeight = dismissView.getHeight();

		ValueAnimator animator = ValueAnimator.ofInt(originalHeight, 1)
				.setDuration(mAnimationTime);

		animator.addListener(new AnimatorListenerAdapter() {
			@Override
			public void onAnimationEnd(Animator animation) {
				--mDismissAnimationRefCount;
				if (mDismissAnimationRefCount == 0) {
					// No active animations, process all pending dismisses.
					// Sort by descending position
					Collections.sort(mPendingDismisses);

					int[] dismissPositions = new int[mPendingDismisses.size()];
					for (int i = mPendingDismisses.size() - 1; i >= 0; i--) {
						dismissPositions[i] = mPendingDismisses.get(i).position;
					}
					mCallback.onDismiss(mListView, dismissPositions);

					ViewGroup.LayoutParams lp;
					for (PendingDismissData pendingDismiss : mPendingDismisses) {
						// Reset view presentation
						ViewHelper.setAlpha(pendingDismiss.view, 1f);
						ViewHelper.setTranslationX(pendingDismiss.view, 0);
						lp = pendingDismiss.view.getLayoutParams();
						lp.height = 0;
						pendingDismiss.view.setLayoutParams(lp);
					}

					mPendingDismisses.clear();
				}
			}
		});

		animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
			@Override
			public void onAnimationUpdate(ValueAnimator valueAnimator) {
				lp.height = (Integer) valueAnimator.getAnimatedValue();
				dismissView.setLayoutParams(lp);
			}
		});

		mPendingDismisses.add(new PendingDismissData(dismissPosition,
				dismissView));
		animator.start();
	}

}