14 Jun 2013

ListView-Swipe To Delete list in android.

Hello Friends, Here I am sharing a code to perform delete operation on listview  by just swiping it to right or left.


activity_main.xml:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:baselineAligned="false"
    android:orientation="horizontal"
    android:padding="16dp" >

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="match_parent"
        android:layout_weight="1"
        android:orientation="vertical" >

        <TextView
            style="?android:listSeparatorTextViewStyle"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="ListView" />

        <ListView
            android:id="@android:id/list"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1" />
    </LinearLayout>


</LinearLayout>

SwipeDismissListViewTouchListener:

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.AbsListView;
import android.widget.ListView;
import com.nineoldandroids.animation.Animator;
import com.nineoldandroids.animation.AnimatorListenerAdapter;
import com.nineoldandroids.animation.ValueAnimator;

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

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

public class SwipeDismissListViewTouchListener implements View.OnTouchListener {

    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 boolean mSwiping;
    private VelocityTracker mVelocityTracker;
    private int mDownPosition;
    private View mDownView;
    private boolean mPaused;

    public interface OnDismissCallback {
    
        void onDismiss(ListView listView, int[] reverseSortedPositions);
    }

 
    public SwipeDismissListViewTouchListener(ListView listView, 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;
        mCallback = callback;
    }

  
    public void setEnabled(boolean enabled) {
        mPaused = !enabled;
    }

  
    public AbsListView.OnScrollListener makeScrollListener() {
        return new AbsListView.OnScrollListener() {
            @Override
            public void onScrollStateChanged(AbsListView absListView, int scrollState) {
                setEnabled(scrollState != AbsListView.OnScrollListener.SCROLL_STATE_TOUCH_SCROLL);
            }

            @Override
            public void onScroll(AbsListView absListView, int i, int i1, int i2) {
            }
        };
    }

    @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;
                }            

                // 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();
                    mDownPosition = mListView.getPositionForView(mDownView);

                    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 (mMinFlingVelocity <= velocityX && velocityX <= mMaxFlingVelocity
                        && velocityY < velocityX) {
                    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 = ListView.INVALID_POSITION;
                mSwiping = false;
                break;
            }

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

                mVelocityTracker.addMovement(motionEvent);
                float deltaX = motionEvent.getRawX() - mDownX;
                if (Math.abs(deltaX) > mSlop) {
                    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) {
                    setTranslationX(mDownView, deltaX);
                    setAlpha(mDownView, Math.max(0f, Math.min(1f,
                            1f - 2f * Math.abs(deltaX) / mViewWidth)));
                    return true;
                }
                break;
            }
        }
        return false;
    }

    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;
        }
    }

    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
                        setAlpha(pendingDismiss.view, 1f);
                        setTranslationX(pendingDismiss.view, 0);
                        lp = pendingDismiss.view.getLayoutParams();
                        lp.height = originalHeight;
                        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();
    }
}

SwipeDismissTouchListener:

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.AnimatorListenerAdapter;
import com.nineoldandroids.animation.ValueAnimator;
import static com.nineoldandroids.view.ViewHelper.setAlpha;
import static com.nineoldandroids.view.ViewHelper.setTranslationX;
import static com.nineoldandroids.view.ViewPropertyAnimator.animate;


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;

  
    public interface OnDismissCallback {
     
        void onDismiss(View view, Object token);
    }

 
    public SwipeDismissTouchListener(View view, Object token, OnDismissCallback callback) {
        ViewConfiguration vc = ViewConfiguration.get(view.getContext());
        mSlop = vc.getScaledTouchSlop();
        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 AnimatorListenerAdapter() {
                                @Override
                                public void onAnimationEnd(Animator animation) {
                                    performDismiss();
                                }
                            });
                } 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;
                    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);
                setTranslationX(mView, 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();
    }
}


MainActivity:

import java.util.ArrayList;
import java.util.Arrays;
import android.app.ListActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

public class MainActivity extends ListActivity
{
    ArrayAdapter<String> mAdapter;

    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Set up ListView example
        String[] items = new String[20];
        for (int i = 0; i < items.length; i++)
        {
            items[i] = "Item " + (i + 1);
        }

        mAdapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_list_item_1,
                android.R.id.text1,
                new ArrayList<String>(Arrays.asList(items)));
        setListAdapter(mAdapter);

        ListView listView = getListView();
        // Create a ListView-specific touch listener. ListViews are given special treatment because
        // by default they handle touches for their list items... i.e. they're in charge of drawing
        // the pressed state (the list selector), handling list item clicks, etc.
        SwipeDismissListViewTouchListener touchListener =
                new SwipeDismissListViewTouchListener(
                        listView,
                        new SwipeDismissListViewTouchListener.OnDismissCallback() {
                            @Override
                            public void onDismiss(ListView listView, int[] reverseSortedPositions) {
                                for (int position : reverseSortedPositions) {
                                    mAdapter.remove(mAdapter.getItem(position));
                                }
                                mAdapter.notifyDataSetChanged();
                            }
                        });
        listView.setOnTouchListener(touchListener);
        // Setting this scroll listener is required to ensure that during ListView scrolling,
        // we don't look for swipes.
        listView.setOnScrollListener(touchListener.makeScrollListener());    
      
    }

    @Override
    protected void onListItemClick(ListView listView, View view, int position, long id)
    {
        Toast.makeText(this,
                "Clicked " + getListAdapter().getItem(position).toString(),
                Toast.LENGTH_SHORT).show();
    }
}
I will be happy if you will provide your feedback or follow this blog. Any suggestion and help will be appreciated.
Thank you :)