/*
* Copyright 2013 Roman Nurik, Tim Roes
*
* 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 de.timroes.swipetodismiss;
import android.annotation.TargetApi;
import android.content.Context;
import android.graphics.Rect;
import android.os.Build;
import android.os.Handler;
import android.os.Message;
import android.support.v4.view.MotionEventCompat;
import android.view.Gravity;
import android.view.LayoutInflater;
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.Button;
import android.widget.ListView;
import android.widget.PopupWindow;
import android.widget.TextView;
import com.nineoldandroids.animation.Animator;
import com.nineoldandroids.animation.AnimatorListenerAdapter;
import com.nineoldandroids.animation.ValueAnimator;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.SortedSet;
import java.util.TreeSet;
import static com.nineoldandroids.view.ViewHelper.setAlpha;
import static com.nineoldandroids.view.ViewHelper.setTranslationX;
import static com.nineoldandroids.view.ViewPropertyAnimator.animate;
/**
* 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.
*
* Read the README file for a detailed explanation on how to use this class.
*/
public final class SwipeDismissList 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 AbsListView mListView;
private OnDismissCallback mCallback;
private int mViewWidth = 1; // 1 and not 0 to prevent dividing by zero
// Transient properties
private SortedSet<PendingDismissData> mPendingDismisses = new TreeSet<PendingDismissData>();
private int mDismissAnimationRefCount = 0;
private float mDownX;
private float mDownY;
private boolean mSwiping;
private VelocityTracker mVelocityTracker;
private int mDownPosition;
private View mDownView;
private int mSwipeLayout;
private boolean mPaused;
private boolean mEnabled;
private float mDensity;
private UndoMode mMode;
private List<Undoable> mUndoActions;
private Handler mHandler;
private PopupWindow mUndoPopup;
private int mPopupXOffset = 0;
private int mPopupYOffset = 15;
private int mPopupGravity = Gravity.CENTER_HORIZONTAL | Gravity.BOTTOM;
private TextView mUndoText;
private Button mUndoButton;
private SwipeDirection mSwipeDirection = SwipeDirection.BOTH;
private int mAutoHideDelay = 5000;
private String mDeleteString = "Item deleted";
private String mDeleteMultipleString = "%d items deleted";
private int mDelayedMsgId;
/**
* Defines the mode a {@link SwipeDismissList} handles multiple undos.
*/
public enum UndoMode {
/**
* Only give the user the possibility to undo the last action.
* As soon as another item is deleted, there is no chance to undo
* the previous deletion.
*/
SINGLE_UNDO,
/**
* Give the user the possibility to undo multiple deletions one by one.
* Every click on Undo will undo the previous deleted item. Undos will be
* collected as long as the undo popup stays open. As soon as the popup
* vanished (because {@link #setAutoHideDelay(int) autoHideDelay} is over)
* all saved undos will be discarded.
*/
MULTI_UNDO,
/**
* Give the user the possibility to undo multiple deletions all together.
* As long as the popup stays open all further deletions will be collected.
* A click on the undo button will undo ALL deletions saved. As soon as
* the popup vanished (because {@link #setAutoHideDelay(int) autoHideDelay}
* is over) all saved undos will be discarded.
*/
COLLAPSED_UNDO
};
/**
* Defines the direction in which the swipe to delete can be done. The default
* is {@link SwipeDirection#BOTH}. Use {@link #setSwipeDirection(de.timroes.swipetodismiss.SwipeDismissList.SwipeDirection)}
* to set the direction.
*/
public enum SwipeDirection {
/**
* The user can swipe each item into both directions (left and right)
* to delete it.
*/
BOTH,
/**
* The user can only swipe the items to the beginning of the item to
* delete it. The start of an item is in Left-To-Right languages the left
* side and in Right-To-Left languages the right side. Before API level
* 17 this is always the left side.
*/
START,
/**
* The user can only swipe the items to the end of the item to delete it.
* This is in Left-To-Right languages the right side in Right-To-Left
* languages the left side. Before API level 17 this will always be the
* right side.
*/
END
}
/**
* The callback interface used by {@link SwipeDismissListViewTouchListener}
* to inform its client about a successful dismissal of one or more list
* item positions.
*/
public interface OnDismissCallback {
/**
* Called when the user has indicated they she would like to dismiss one
* or more list item positions.
*
* @param listView The originating {@link ListView}.
* @param position The position of the item to dismiss.
*/
Undoable onDismiss(AbsListView listView, int position);
}
/**
* An implementation of this abstract class must be returned by the
* {@link OnDismissCallback#onDismiss(android.widget.ListView, int)} method,
* if the user should be able to undo that dismiss. If the action will be undone
* by the user {@link #undo()} will be called. That method should undo the previous
* deletion of the item and add it back to the adapter. Read the README file for
* more details. If you implement the {@link #getTitle()} method, the undo popup
* will show an individual title for that item. Otherwise the default title
* (set via {@link #setUndoString(java.lang.String)}) will be shown.
*/
public abstract static class Undoable {
/**
* Returns the individual undo message for this item shown in the
* popup dialog.
*
* @return The individual undo message.
*/
public String getTitle() {
return null;
}
/**
* Undoes the deletion.
*/
public abstract void undo();
/**
* Will be called when this Undoable won't be able to undo anymore,
* meaning the undo popup has disappeared from the screen.
*/
public void discard() { }
}
/**
* 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 SwipeDismissList(AbsListView listView, OnDismissCallback callback) {
this(listView, callback, UndoMode.SINGLE_UNDO);
}
/**
* 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.
* @param mode The mode this list handles multiple undos.
*/
public SwipeDismissList(AbsListView listView, OnDismissCallback callback, UndoMode mode) {
if(listView == null) {
throw new IllegalArgumentException("listview must not be null.");
}
mHandler = new HideUndoPopupHandler(this);
mListView = listView;
mCallback = callback;
mMode = mode;
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);
mDensity = mListView.getResources().getDisplayMetrics().density;
// -- Load undo popup --
LayoutInflater inflater = (LayoutInflater) mListView.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View v = inflater.inflate(R.layout.undo_popup, null);
mUndoButton = (Button)v.findViewById(R.id.undo);
mUndoButton.setOnClickListener(new UndoHandler());
mUndoButton.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
// If user tabs "undo" button, reset delay time to remove popup
mDelayedMsgId++;
return false;
}
});
mUndoText = (TextView)v.findViewById(R.id.text);
mUndoPopup = new PopupWindow(v);
mUndoPopup.setAnimationStyle(R.style.fade_animation);
// Get scren width in dp and set width respectively
int xdensity = (int)(mListView.getContext().getResources().getDisplayMetrics().widthPixels / mDensity);
if(xdensity < 300) {
mUndoPopup.setWidth((int)(mDensity * 280));
} else if(xdensity < 350) {
mUndoPopup.setWidth((int)(mDensity * 300));
} else if(xdensity < 500) {
mUndoPopup.setWidth((int)(mDensity * 330));
} else {
mUndoPopup.setWidth((int)(mDensity * 450));
}
mUndoPopup.setHeight((int)(mDensity * 56));
// -- END Load undo popu --
listView.setOnTouchListener(this);
listView.setOnScrollListener(this.makeScrollListener());
mEnabled = true;
switch(mode) {
case SINGLE_UNDO:
mUndoActions = new ArrayList<Undoable>(1);
break;
default:
mUndoActions = new ArrayList<Undoable>(10);
break;
}
}
/**
* Enables or disables (pauses or resumes) watching for swipe-to-dismiss
* gestures.
*
* @param enabled Whether or not to watch for gestures.
*/
public void setEnabled(boolean enabled) {
mEnabled = enabled;
}
/**
* Sets the time in milliseconds after which the undo popup automatically
* disappears.
*
* @param delay Delay in milliseconds.
*/
public void setAutoHideDelay(int delay) {
mAutoHideDelay = delay;
}
public void setSwipeLayout(int swipeLayout) {
mSwipeLayout = swipeLayout;
}
/**
* Sets the offset, in dips, of the x position of
* the undo popup.
*
* @param popupXOffset x position in dips.
*/
public void setPopupXOffset(int popupXOffset) {
mPopupXOffset = popupXOffset;
}
/**
* Sets the offset, in dips, of the y position of
* the undo popup.
*
* @param popupYOffset y position in dips.
*/
public void setPopupYOffset(int popupYOffset) {
mPopupYOffset = popupYOffset;
}
/**
* Sets the Gravity controlling the placement of
* the undo popup.
*
* @param popupGravity the gravity which controls the placement of the popup window
*/
public void setPopupGravity(int popupGravity) {
mPopupGravity = popupGravity;
}
/**
* Sets the directions in which a list item can be swiped to delete.
* By default this is set to {@link SwipeDirection#BOTH} so that an item
* can be swiped into both directions.
*
* @param direction The direction to limit the swipe to.
*/
public void setSwipeDirection(SwipeDirection direction) {
mSwipeDirection = direction;
}
/**
* Sets the string shown in the undo popup. This will only show if
* the {@link Undoable} returned by the {@link OnDismissCallback} returns
* {@code null} from its {@link Undoable#getTitle()} method.
*
* @param msg The string shown in the undo popup.
*/
public void setUndoString(String msg) {
mDeleteString = msg;
}
/**
* Sets the string shown in the undo popup, when {@link UndoMode} is set to
* {@link UndoMode#MULTI_UNDO} or {@link UndoMode#COLLAPSED_UNDO} and
* multiple deletions has been stored for undo. If this string contains
* one {@code %d} inside, this will be filled by the numbers of stored undos.
*
* @param msg The string shown in the undo popup for multiple undos.
*/
public void setUndoMultipleString(String msg) {
mDeleteMultipleString = msg;
}
/**
* Discard all stored undos and hide the undo popup dialog.
*/
public void discardUndo() {
for(Undoable undoable : mUndoActions) {
undoable.discard();
}
mUndoActions.clear();
mUndoPopup.dismiss();
}
/**
* Returns an {@link android.widget.AbsListView.OnScrollListener} to be
* added to the {@link ListView} using
* {@link ListView#setOnScrollListener(android.widget.AbsListView.OnScrollListener)}.
* If a scroll listener is already assigned, the caller should still pass
* scroll changes through to this listener. This will ensure that this
* {@link SwipeDismissListViewTouchListener} is paused during list view
* scrolling.</p>
*
* @see {@link SwipeDismissListViewTouchListener}
*/
private AbsListView.OnScrollListener makeScrollListener() {
return new AbsListView.OnScrollListener() {
@Override
public void onScrollStateChanged(AbsListView absListView, int scrollState) {
mPaused = !(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 (MotionEventCompat.getActionMasked(motionEvent)) {
case MotionEvent.ACTION_DOWN: {
if (mPaused || !mEnabled) {
return false;
}
resetSwipeState();
// 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)) {
if (mSwipeLayout != 0) {
View swipeView = child.findViewById(mSwipeLayout);
if (swipeView != null) {
mDownView = swipeView;
break;
}
}
mDownView = child;
break;
}
}
if (mDownView != null) {
mDownX = motionEvent.getRawX();
mDownY = motionEvent.getRawY();
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 && mSwiping) {
dismiss = true;
dismissRight = deltaX > 0;
} else if (mMinFlingVelocity <= velocityX && velocityX <= mMaxFlingVelocity
&& velocityY < velocityX && mSwiping && isDirectionValid(mVelocityTracker.getXVelocity())
&& deltaX >= mViewWidth * 0.2f) {
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;
mPaused = true;
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);
}
resetSwipeState();
break;
}
case MotionEvent.ACTION_MOVE: {
if(mUndoPopup.isShowing()) {
// Send a delayed message to hide popup
mHandler.sendMessageDelayed(mHandler.obtainMessage(mDelayedMsgId),
mAutoHideDelay);
}
if (mVelocityTracker == null || mPaused || !mEnabled) {
break;
}
mVelocityTracker.addMovement(motionEvent);
float deltaX = motionEvent.getRawX() - mDownX;
float deltaY = motionEvent.getRawY() - mDownY;
// Only start swipe in correct direction
if(isDirectionValid(deltaX)) {
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
| (MotionEventCompat.getActionIndex(motionEvent)
<< MotionEvent.ACTION_POINTER_INDEX_SHIFT));
mListView.onTouchEvent(cancelEvent);
cancelEvent.recycle();
}
} else {
// If we swiped into wrong direction, act like this was the new
// touch down point
mDownX = motionEvent.getRawX();
deltaX = 0;
}
if (mSwiping) {
setTranslationX(mDownView, deltaX);
setAlpha(mDownView, Math.max(0f, Math.min(1f,
1f - 2f * Math.abs(deltaX) / mViewWidth)));
return true;
}
break;
}
}
return false;
}
private void resetSwipeState() {
if (mVelocityTracker != null) {
mVelocityTracker.recycle();
}
mVelocityTracker = null;
mDownX = 0;
mDownY = 0;
mDownView = null;
mDownPosition = ListView.INVALID_POSITION;
mSwiping = false;
}
/**
* Checks whether the delta of a swipe indicates, that the swipe is in the
* correct direction, regarding the direction set via
* {@link #setSwipeDirection(de.timroes.swipetodismiss.SwipeDismissList.SwipeDirection)}
*
* @param deltaX The delta of x coordinate of the swipe.
* @return Whether the delta of a swipe is in the right direction.
*/
@TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1)
private boolean isDirectionValid(float deltaX) {
int rtlSign = 1;
// On API level 17 and above, check if we are in a Right-To-Left layout
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
if(mListView.getLayoutDirection() == View.LAYOUT_DIRECTION_RTL) {
rtlSign = -1;
}
}
// Check if swipe has been done in the corret direction
switch(mSwipeDirection) {
default:
case BOTH:
return true;
case START:
return rtlSign * deltaX < 0;
case END:
return rtlSign * deltaX > 0;
}
}
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.
for(PendingDismissData dismiss : mPendingDismisses) {
if(mMode == UndoMode.SINGLE_UNDO) {
for(Undoable undoable : mUndoActions) {
undoable.discard();
}
mUndoActions.clear();
}
Undoable undoable = mCallback.onDismiss(mListView, dismiss.position);
if(undoable != null) {
mUndoActions.add(undoable);
}
mDelayedMsgId++;
}
if(!mUndoActions.isEmpty()) {
changePopupText();
changeButtonLabel();
// Show undo popup
mUndoPopup.showAtLocation(mListView,
mPopupGravity,
(int)(mDensity * mPopupXOffset),
(int)(mDensity * mPopupYOffset));
}
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();
}
mPaused = false;
}
});
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();
}
/**
* Changes text in the popup depending on stored undos.
*/
private void changePopupText() {
String msg = "";
if(mUndoActions.size() > 1 && mDeleteMultipleString != null) {
msg = String.format(mDeleteMultipleString, mUndoActions.size());
} else if(mUndoActions.size() >= 1) {
// Set title from single undoable or when no multiple deletion string
// is given
if(mUndoActions.get(mUndoActions.size() - 1).getTitle() != null) {
msg = mUndoActions.get(mUndoActions.size() - 1).getTitle();
} else {
msg = mDeleteString;
}
}
mUndoText.setText(msg);
}
private void changeButtonLabel() {
String msg;
if(mUndoActions.size() > 1 && mMode == UndoMode.COLLAPSED_UNDO) {
msg = mListView.getResources().getString(R.string.undoall);
} else {
msg = mListView.getResources().getString(R.string.undo);
}
mUndoButton.setText(msg);
}
/**
* Takes care of undoing a dismiss. This will be added as a
* {@link View.OnClickListener} to the undo button in the undo popup.
*/
private class UndoHandler implements View.OnClickListener {
public void onClick(View v) {
if(!mUndoActions.isEmpty()) {
switch(mMode) {
case SINGLE_UNDO:
mUndoActions.get(0).undo();
mUndoActions.clear();
break;
case COLLAPSED_UNDO:
Collections.reverse(mUndoActions);
for(Undoable undo : mUndoActions) {
undo.undo();
}
mUndoActions.clear();
break;
case MULTI_UNDO:
mUndoActions.get(mUndoActions.size() - 1).undo();
mUndoActions.remove(mUndoActions.size() - 1);
break;
}
}
// Dismiss dialog or change text
if(mUndoActions.isEmpty()) {
mUndoPopup.dismiss();
} else {
changePopupText();
changeButtonLabel();
}
mDelayedMsgId++;
}
}
/**
* Handler used to hide the undo popup after a special delay.
*/
private static class HideUndoPopupHandler extends Handler {
private final WeakReference<SwipeDismissList> parentRef;
public HideUndoPopupHandler(SwipeDismissList parent) {
this.parentRef = new WeakReference<SwipeDismissList>(parent);
}
@Override
public void handleMessage(Message msg) {
SwipeDismissList parent = parentRef.get();
if(parent != null && msg.what == parent.mDelayedMsgId) {
// Call discard on any element
for(Undoable undo : parent.mUndoActions) {
undo.discard();
}
parent.mUndoActions.clear();
parent.mUndoPopup.dismiss();
}
}
}
}
