Android Swipe on List
I had the same problem and I didn't find my answer here.
I wanted to detect a swipe action in ListView item and mark it as swiped, while continue to support OnItemClick and OnItemLongClick.
Here is me solution:
1st The SwipeDetector class:
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
public class SwipeDetector implements View.OnTouchListener {
public static enum Action {
LR, // Left to Right
RL, // Right to Left
TB, // Top to bottom
BT, // Bottom to Top
None // when no action was detected
}
private static final String logTag = "SwipeDetector";
private static final int MIN_DISTANCE = 100;
private float downX, downY, upX, upY;
private Action mSwipeDetected = Action.None;
public boolean swipeDetected() {
return mSwipeDetected != Action.None;
}
public Action getAction() {
return mSwipeDetected;
}
@Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
downX = event.getX();
downY = event.getY();
mSwipeDetected = Action.None;
return false; // allow other events like Click to be processed
case MotionEvent.ACTION_UP:
upX = event.getX();
upY = event.getY();
float deltaX = downX - upX;
float deltaY = downY - upY;
// horizontal swipe detection
if (Math.abs(deltaX) > MIN_DISTANCE) {
// left or right
if (deltaX < 0) {
Log.i(logTag, "Swipe Left to Right");
mSwipeDetected = Action.LR;
return false;
}
if (deltaX > 0) {
Log.i(logTag, "Swipe Right to Left");
mSwipeDetected = Action.RL;
return false;
}
} else if (Math.abs(deltaY) > MIN_DISTANCE) { // vertical swipe
// detection
// top or down
if (deltaY < 0) {
Log.i(logTag, "Swipe Top to Bottom");
mSwipeDetected = Action.TB;
return false;
}
if (deltaY > 0) {
Log.i(logTag, "Swipe Bottom to Top");
mSwipeDetected = Action.BT;
return false;
}
}
return false;
}
return false;
}
}
2nd I use the swipe detector class in the list view:
final ListView lv = getListView();
final SwipeDetector swipeDetector = new SwipeDetector();
lv.setOnTouchListener(swipeDetector);
lv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
if (swipeDetector.swipeDetected()){
// do the onSwipe action
} else {
// do the onItemClick action
}
}
});
lv.setOnItemLongClickListener(new OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> parent, View view,int position, long id) {
if (swipeDetector.swipeDetected()){
// do the onSwipe action
} else {
// do the onItemLongClick action
}
}
});
This way I can support 3 actions - swipe, click, long click and I can use the ListView item info.
ADDED LATER:
Since ListView catches a scrolling action, it is sometimes hard to swipe. To fix it, I made the following change to SwipeDetector.onTouch:
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN: {
downX = event.getX();
downY = event.getY();
mSwipeDetected = Action.None;
return false; // allow other events like Click to be processed
}
case MotionEvent.ACTION_MOVE: {
upX = event.getX();
upY = event.getY();
float deltaX = downX - upX;
float deltaY = downY - upY;
// horizontal swipe detection
if (Math.abs(deltaX) > HORIZONTAL_MIN_DISTANCE) {
// left or right
if (deltaX < 0) {
Log.i(logTag, "Swipe Left to Right");
mSwipeDetected = Action.LR;
return true;
}
if (deltaX > 0) {
Log.i(logTag, "Swipe Right to Left");
mSwipeDetected = Action.RL;
return true;
}
} else
// vertical swipe detection
if (Math.abs(deltaY) > VERTICAL_MIN_DISTANCE) {
// top or down
if (deltaY < 0) {
Log.i(logTag, "Swipe Top to Bottom");
mSwipeDetected = Action.TB;
return false;
}
if (deltaY > 0) {
Log.i(logTag, "Swipe Bottom to Top");
mSwipeDetected = Action.BT;
return false;
}
}
return true;
}
}
return false;
}
here's a snippet I use for detecting swipes. You could then use a viewflipper to change the view.
@Override
public boolean onTouchEvent(MotionEvent event) {
if (gestureDetector.onTouchEvent(event)) {
return true;
} else {
return false;
}
}
private static final int SWIPE_MIN_DISTANCE = 30;
private static final int SWIPE_MAX_OFF_PATH = 250;
private static final int SWIPE_THRESHOLD_VELOCITY = 200;
class MyGestureDetector extends SimpleOnGestureListener {
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
try {
if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH)
return false;
// right to left swipe
if (e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE
&& Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
leftFling();
} else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE
&& Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
rightFling();
}
} catch (Exception e) {
// nothing
}
return false;
}
}
Here is a very simplified version using the two listeners (onTouch for swipe detection, and onClickIem for item click detection) using the isSwipe flag to stop the onClickItemListener until its confirmed that is was not a swipe
Detecting the click
taking into consideration that it is not a swipe first
listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3)
{
if(!isSwipe)
{
adapter.increase(arg2);
adapter.notifyDataSetChanged();
}
}
});
Detecting the swipe
listView.setOnTouchListener(new OnTouchListener() {
private int action_down_x = 0;
private int action_up_x = 0;
private int difference = 0;
@Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
action_down_x = (int) event.getX();
isSwipe=false; //until now
break;
case MotionEvent.ACTION_MOVE:
if(!isSwipe)
{
action_up_x = (int) event.getX();
difference = action_down_x - action_up_x;
if(Math.abs(difference)>50)
{
Log.d("action","action down x: "+action_down_x);
Log.d("action","action up x: "+action_up_x);
Log.d("action","difference: "+difference);
//swipe left or right
if(difference>0){
//swipe left
Log.d("action","swipe left");
adapter.decrease(selectedItem);
adapter.notifyDataSetChanged();
}
else{
//swipe right
Log.d("action","swipe right");
}
isSwipe=true;
}
}
break;
case MotionEvent.ACTION_UP:
Log.d("action", "ACTION_UP - ");
action_down_x = 0;
action_up_x = 0;
difference = 0;
break;
}
return false; //to allow the clicklistener to work after
}
})