I am trying to make an app where a user can swipe and change which fragment they are seeing on the screen. I can not use view pager because I want the user to be able to swipe to different fragments forever. Here is the detector in my fragment:
class MyGestureDetector extends SimpleOnGestureListener {
@Override
public boolean onDown(MotionEvent e) {
return true;
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
if(e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE & Math.abs(velocityX) > 10) {
left();
} else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE & Math.abs(velocityX) > 10) {
right();
}
return false;
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY){
if(e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE & distanceX > distanceY) {
left();
} else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE & distanceX > distanceY) {
right();
}
return false;
}
}
public void right(){
mCallback.dateNumber(true);
sportView.setText("Loading");
}public void left(){
mCallback.dateNumber(false);
sportView.setText("Loading");
}
In my activity, here is the listener that I added to change fragments:
@Override
public void dateNumber(Boolean left_right) {
//true == right
//false == left
if(left_right == false){
day = day + 1;
Fragment1 rightFragment = new Fragment1();
Bundle args = new Bundle();
args.putInt("day", day);
rightFragment.setArguments(args);
android.support.v4.app.FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.fragment_container, rightFragment);
transaction.addToBackStack(null);
transaction.commit();
}else if(left_right == true){
day = day - 1;
Fragment1 leftFragment = new Fragment1();
Bundle args = new Bundle();
args.putInt("day", day);
leftFragment.setArguments(args);
android.support.v4.app.FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.fragment_container, leftFragment);
transaction.addToBackStack(null);
transaction.commit();
}
left_right = null;
}
I know that the swipe gesture is always being recognized but sometimes the new fragment won't open up. Does anyone know why?
First of all, you can really simplify your swipe code using my droidQuery library:
//global variables
private boolean isSwiping = false;
private SwipeDetector.Direction swipeDirection = null;
private View v;//set to the parent layout of the fragments.
//swipe-handling code
$.with(v).swipe(new Function() {
@Override
public void invoke($ droidQuery, Object... params) {
if (params[0] == SwipeDetector.Direction.START)
isSwiping = true;
else if (params[0] == SwipeDetector.Direction.STOP) {
if (isSwiping) {
isSwiping = false;
if (swipeDirection != null) {
switch(swipeDirection) {
case DOWN :
//TODO: Down swipe complete, so do something
break;
case UP :
//TODO: Up swipe complete, so do something
break;
case LEFT :
//TODO: Left swipe complete, so do something
break;
case RIGHT :
//TODO: Right swipe complete, so do something (such as):
day++;
Fragment1 rightFragment = new Fragment1();
Bundle args = new Bundle();
args.putInt("day", day);
rightFragment.setArguments(args);
android.support.v4.app.FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.fragment_container, rightFragment);
transaction.addToBackStack(null);
transaction.commit();
break;
default :
break;
}
}
}
}
else {
swipeDirection = (SwipeDetector.Direction) params[0];
}
}
});
You can find more on Fragment transactions here.
Also, consider keeping an int offset variable that keeps track of the +/- offset from zero. So for instance, you could get the already-instantiated Fragments from an ArrayList, then just swap out the one at mArrayList.get(offset), and when flinging right, do offset++, and 'offset--` for left swipes.
As requested in the comments, this code can be used to handle swipes and a child image click:
Include the SwipeInterceptorView in your main Layout (res/layout/main.xml):
<?xml version="1.0" encoding="utf-8"?>
<self.philbrown.SwipeInterceptorView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/swipe_view"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</self.philbrown.SwipeInterceptorView>
You will need to have class variables:
SwipeInterceptorView view;//instantiated in onCreate
ImageView fragImage;//must be instantiated when the new Fragment is transitioned in
Next, include the following components in onCreate:
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//set main view to the main layout
setContentView(R.layout.main);
//get a reference to the content view
view = (SwipeInterceptorView) findViewById(R.id.swipe_view);
//add Swiper
view.setSwipeListener(new SwipeListener() {
public void onUpSwipe(View v) {
//TODO handle up swipe
}
public void onRightSwipe(View v) {
//TODO handle right swipe
}
public void onLeftSwipe(View v) {
//TODO handle left swipe
}
public void onDownSwipe(View v) {
//TODO handle down swipe
}
});
view.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
return super.onTouch(v, event);
}
});
}
When the new Fragment containing the ImageView is transitioned in, you need to reference it and update the swipe interceptor's onTouch method:
fragImage = (ImageView) fragment/* references the now non-null, on-display fragment */.getView().findViewById(R.id.yourImageId);
int[] origin = new int[2];
fragImage.getLocationOnScreen(origin);
final Rect bounds = new Rect(origin[0], origin[1], fragImage.getRight(), fragImage.getBottom());
view.setOnTouchListener(new View.OnTouchListener() {
@Override
public void onTouch(View v, MotionEvent event) {
if (bounds.contains(event.getRawX(), event.getRawY())) {
return false;//now clicks will be handled by the Image.
}
return v.onTouchEvent(event);
}
});