Android Open Source - Pimp_my_Z1 Swipe Dismiss Touch Listener

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License

The source code is released under:
GNU General Public License
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Java Source Code

package com.fima.cardsui;
/*from  w ww .ja  v a 2 s  . c o  m*/
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewGroup;

import com.nineoldandroids.animation.Animator;
import com.nineoldandroids.animation.Animator.AnimatorListener;
import com.nineoldandroids.animation.AnimatorListenerAdapter;
import com.nineoldandroids.animation.ValueAnimator;
import com.nineoldandroids.view.ViewHelper;

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

/**
 * A {@link android.view.View.OnTouchListener} that makes any {@link View}
 * dismissable when the user swipes (drags her finger) horizontally across the
 * view.
 * 
 * <p>
 * <em>For {@link android.widget.ListView} list items that don't manage their own touch events
 * (i.e. you're using
 * {@link android.widget.ListView#setOnItemClickListener(android.widget.AdapterView.OnItemClickListener)}
 * or an equivalent listener on {@link android.app.ListActivity} or
 * {@link android.app.ListFragment}, use {@link SwipeDismissListViewTouchListener} instead.</em>
 * </p>
 * 
 * <p>
 * Example usage:
 * </p>
 * 
 * <pre>
 * view.setOnTouchListener(new SwipeDismissTouchListener(view, null, // Optional
 *                                   // token/cookie
 *                                   // object
 *     new SwipeDismissTouchListener.OnDismissCallback() {
 *       public void onDismiss(View view, Object token) {
 *         parent.removeView(view);
 *       }
 *     }));
 * </pre>
 * 
 * <p>
 * This class Requires API level 12 or later due to use of
 * {@link android.view.ViewPropertyAnimator}.
 * </p>
 * 
 * @see SwipeDismissListViewTouchListener
 */
public class SwipeDismissTouchListener implements View.OnTouchListener {
  // Cached ViewConfiguration and system-wide constant values
  private int mSlop;
  private int mMinFlingVelocity;
  private int mMaxFlingVelocity;
  private long mAnimationTime;

  // Fixed properties
  private View mView;
  private OnDismissCallback mCallback;
  private int mViewWidth = 1; // 1 and not 0 to prevent dividing by zero

  // Transient properties
  private float mDownX;
  private boolean mSwiping;
  private Object mToken;
  private VelocityTracker mVelocityTracker;
  private float mTranslationX;

  /**
   * The callback interface used by {@link SwipeDismissTouchListener} to
   * inform its client about a successful dismissal of the view for which it
   * was created.
   */
  public interface OnDismissCallback {
    /**
     * Called when the user has indicated they she would like to dismiss the
     * view.
     * 
     * @param view
     *            The originating {@link View} to be dismissed.
     * @param token
     *            The optional token passed to this object's constructor.
     */
    public void onDismiss(View view, Object token);
  }

  /**
   * Constructs a new swipe-to-dismiss touch listener for the given view.
   * 
   * @param view
   *            The view to make dismissable.
   * @param token
   *            An optional token/cookie object to be passed through to the
   *            callback.
   * @param callback
   *            The callback to trigger when the user has indicated that she
   *            would like to dismiss this view.
   */
  public SwipeDismissTouchListener(View view, Object token,
      OnDismissCallback callback) {
    ViewConfiguration vc = ViewConfiguration.get(view.getContext());
    mSlop = vc.getScaledTouchSlop() * 2;
    mMinFlingVelocity = vc.getScaledMinimumFlingVelocity();
    mMaxFlingVelocity = vc.getScaledMaximumFlingVelocity();
    mAnimationTime = view.getContext().getResources()
        .getInteger(android.R.integer.config_shortAnimTime);
    mView = view;
    mToken = token;
    mCallback = callback;
  }

  @Override
  public boolean onTouch(View view, MotionEvent motionEvent) {
    // offset because the view is translated during swipe
    motionEvent.offsetLocation(mTranslationX, 0);

    if (mViewWidth < 2) {
      mViewWidth = mView.getWidth();
    }

    switch (motionEvent.getActionMasked()) {
    case MotionEvent.ACTION_DOWN: {
      // TODO: ensure this is a finger, and set a flag
      mDownX = motionEvent.getRawX();
      mVelocityTracker = VelocityTracker.obtain();
      mVelocityTracker.addMovement(motionEvent);
      view.onTouchEvent(motionEvent);
      return false;
    }

    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 (mMinFlingVelocity <= velocityX
          && velocityX <= mMaxFlingVelocity && velocityY < velocityX) {
        dismiss = true;
        dismissRight = mVelocityTracker.getXVelocity() > 0;
      }
      if (dismiss) {
        // dismiss
        animate(mView)
            .translationX(dismissRight ? mViewWidth : -mViewWidth)
            .alpha(0).setDuration(mAnimationTime)
            .setListener(new AnimatorListener() {

              @Override
              public void onAnimationStart(Animator arg0) {
                // TODO Auto-generated method stub

              }

              @Override
              public void onAnimationRepeat(Animator arg0) {
                // TODO Auto-generated method stub

              }

              @Override
              public void onAnimationEnd(Animator arg0) {
                performDismiss();

              }

              @Override
              public void onAnimationCancel(Animator arg0) {
                // TODO Auto-generated method stub

              }
            });
      } else {
        // cancel
        animate(mView).translationX(0).alpha(1)
            .setDuration(mAnimationTime).setListener(null);

      }
      mVelocityTracker = null;
      mTranslationX = 0;
      mDownX = 0;
      mSwiping = false;
      break;
    }

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

      mVelocityTracker.addMovement(motionEvent);
      float deltaX = motionEvent.getRawX() - mDownX;
      if (Math.abs(deltaX) > mSlop) {
        mSwiping = true;
        mView.getParent().requestDisallowInterceptTouchEvent(true);

        // Cancel listview's touch
        MotionEvent cancelEvent = MotionEvent.obtain(motionEvent);
        cancelEvent
            .setAction(MotionEvent.ACTION_CANCEL
                | (motionEvent.getActionIndex() << MotionEvent.ACTION_POINTER_INDEX_SHIFT));
        mView.onTouchEvent(cancelEvent);
      }

      if (mSwiping) {
        mTranslationX = deltaX;
        ViewHelper.setTranslationX(mView, deltaX);

        // TODO: use an ease-out interpolator or such
        setAlpha(
            mView,
            Math.max(
                0f,
                Math.min(1f, 1f - 2f * Math.abs(deltaX)
                    / mViewWidth)));
        return true;
      }
      break;
    }
    }
    return false;
  }

  private void performDismiss() {
    // Animate the dismissed view to zero-height and then fire the dismiss
    // callback.
    // This triggers layout on each animation frame; in the future we may
    // want to do something
    // smarter and more performant.

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

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

    animator.addListener(new AnimatorListenerAdapter() {
      @Override
      public void onAnimationEnd(Animator animation) {
        mCallback.onDismiss(mView, mToken);
        // Reset view presentation
        setAlpha(mView, 1f);
        ViewHelper.setTranslationX(mView, 0);
        // mView.setAlpha(1f);
        // mView.setTranslationX(0);
        lp.height = originalHeight;
        mView.setLayoutParams(lp);
      }
    });

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

    animator.start();
  }
}
Java Source Code List
