I created a ViewPager and everything is working fine, however I want to have a previous next button outside of ViewPager which can be used to navigate inside ViewPager. How can I go to next Item on ViewPager without swiping manually?
As blessenm answered viewpager.setCurrentItem(int index) is the way to go.
A complete implementation just for completeness:
public void MoveNext(View view) {
//it doesn't matter if you're already in the last item
pager.setCurrentItem(pager.getCurrentItem() + 1);
}
public void MovePrevious(View view) {
//it doesn't matter if you're already in the first item
pager.setCurrentItem(pager.getCurrentItem() - 1);
}
Easiest way is:
nextButton.setOnClickListener { pager.arrowScroll(View.FOCUS_RIGHT) }
prevButton.setOnClickListener { pager.arrowScroll(View.FOCUS_LEFT) }
i fix it Better, ty Androiderson.
private void MoveNextTopSlideShow(View view)
{
if (_viewPager_TopImageSlide.CurrentItem == _viewPager_TopImageSlide.ChildCount)
{
if (_viewPager_TopImageSlide.ChildCount > 0)
{
_viewPager_TopImageSlide.SetCurrentItem(0,true);
}
}
else
{
//it doesn't matter if you're already in the last item
_viewPager_TopImageSlide.SetCurrentItem(_viewPager_TopImageSlide.CurrentItem + 1, true);
}
}
private void MovePreviousTopSlideShow(View view)
{
if (_viewPager_TopImageSlide.CurrentItem == 0)
{
if (_viewPager_TopImageSlide.ChildCount > 0)
{
_viewPager_TopImageSlide.SetCurrentItem(_viewPager_TopImageSlide.ChildCount-1, true);
}
}
else
{
//it doesn't matter if you're already in the first item
_viewPager_TopImageSlide.SetCurrentItem(_viewPager_TopImageSlide.CurrentItem - 1, true);
}
}
Related
I have one activity with one RecyclerView (SuperSlim library) and a detail activity, when I click a item of that list, detail activity will be open. The problem is when I go back, I'm trying to set the clicked element as the first visible element in the list but I get this horrible animation:
This is my onActivityReenter()
#Override
public void onActivityReenter(int resultCode, Intent data) {
super.onActivityReenter(resultCode, data);
Log.d(TAG, "onActivityReenter() called with: resultCode = [" + resultCode + "], data = [" + data + "]");
mTmpReenterState = new Bundle(data.getExtras());
int startingPosition = mTmpReenterState.getInt(EXTRA_STARTING_ITEM_POSITION);
int currentPosition = mTmpReenterState.getInt(EXTRA_CURRENT_ITEM_POSITION);
mRecycler.scrollToPosition(currentPosition);
postponeEnterTransition();
mRecycler.getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
#Override
public boolean onPreDraw() {
mRecycler.getViewTreeObserver().removeOnPreDrawListener(this);
// TODO: figure out why it is necessary to request layout here in order to get a smooth transition.
mRecycler.requestLayout();
startPostponedEnterTransition();
return true;
}
});
}
And my SharedElementCallback:
private final SharedElementCallback exitTransitionCallBack = new SharedElementCallback() {
#Override
public void onMapSharedElements(List<String> names, Map<String, View> sharedElements) {
if (mTmpReenterState == null) {
// If mTmpReenterState is null, then the activity is exiting.
View navigationBar = findViewById(android.R.id.navigationBarBackground);
View statusBar = findViewById(android.R.id.statusBarBackground);
if (navigationBar != null) {
names.add(navigationBar.getTransitionName());
sharedElements.put(navigationBar.getTransitionName(), navigationBar);
}
if (statusBar != null) {
names.add(statusBar.getTransitionName());
sharedElements.put(statusBar.getTransitionName(), statusBar);
}
} else {
int startingPosition = mTmpReenterState.getInt(EXTRA_STARTING_ITEM_POSITION);
int currentPosition = mTmpReenterState.getInt(EXTRA_CURRENT_ITEM_POSITION);
if (startingPosition != currentPosition) {
// If startingPosition != currentPosition the user must have swiped to a
// different page in the DetailsActivity. We must update the shared element
// so that the correct one falls into place.
sharedElements.clear();
sharedElements.put("number", mLayoutManager.findViewByPosition(currentPosition).findViewById(R.id.text_number));
sharedElements.put("day", mLayoutManager.findViewByPosition(currentPosition).findViewById(R.id.text_day));
sharedElements.put("recycler", mLayoutManager.findViewByPosition(currentPosition + 1).findViewById(R.id.recycler));
}
mTmpReenterState = null;
}
}
};
I think the problem is that the activity try to make an animation from the original item position to the top to the list, but I don't know how avoid that.
Does anyone know how to fix this??
Thanks in advance guys!!!
After a while I've realized that the problem that I was updating the Main Activity list with a notifyItemChanged(int) by LocalBroadcast and the standard recyclerView animation made that glitch. I solve the problem using:
RecyclerView.setItemAnimator(null)
because the standard didn't work
((SimpleItemAnimator) RecyclerView.getItemAnimator())
.setSupportsChangeAnimations(false)
So the problem is nothing to do with SharedElements.
I am using swipelayout from daimajia.I get some data from services.When the service has a date than will visible an icon that will open the left sideBut it do nothing when clicking the icon.I have no error that's the reason why cannot resolve it.The action is when clicking the icon,that visible a textview and start a chronometer.
Here is my swipeListener
private SwipeListener swipeListener = new SwipeListener() {
#Override
public void onStartOpen(SwipeLayout layout, SwipeLayout.DragEdge edge) {
if (edge == SwipeLayout.DragEdge.Left && viewHolder.discountText != null) {
**viewHolder.discountText.setTimeByTag().play();**
LogUtils.LogE("Left Open...");
}
}
#Override
public void onOpen(SwipeLayout layout, SwipeLayout.DragEdge edge) {
super.onOpen(layout, edge);
if (edge == SwipeLayout.DragEdge.Left && viewHolder.discountText != null) {
viewHolder.discountText.setTimeByTag().play();
LogUtils.LogE("Left Open...");
}
}
#Override
public void onClose(SwipeLayout layout, SwipeLayout.DragEdge edge) {
if (edge == SwipeLayout.DragEdge.Left && viewHolder.discountText != null) {
viewHolder.discountText.stop();
LogUtils.LogE("Left Close!");
}
}
};
public void openLeft() {
LogUtils.LogE("onClick openLeft-");
if (getSwipeLayout() == null){
LogUtils.LogE("onClick -null-");
return;
}
if (!getSwipeLayout().isOpen()) {
getSwipeLayout().open(true, SwipeLayout.DragEdge.Left);
LogUtils.LogE("onClick --");
}
}
all the codes working in other my fragments.I need some idea what's the reason that it not give true action that swipe to left.
EDIT:
Here is the Logs:
In this picture I have 2 items there which it's in my favorite page.The last one item has end date that will be visible the icon(ImageView).When pressing the icon,it should swipe to left side but it's not working and give the result like this picture which I'm shared.
EDIT
There is something more.I had looked the codes in debug mode and give here an message:
but put define swipeLayout into my code:
sl.setShowMode(SwipeLayout.ShowMode.LayDown);
sl.setDragEdges(SwipeLayout.DragEdge.Left, SwipeLayout.DragEdge.Right);
sl.setBottomViewIds(R.id.productBottomLeft, R.id.productBottomRight, SwipeLayout.EMPTY_LAYOUT, SwipeLayout.EMPTY_LAYOUT);
TextView button = SwipeLayout.findViewById(R.id.yourButtonId) //the bottom view;
button.setOnClickListener(v -> yourMethod());
So my activity uses the PageAdapter and ViewPager correctly, where 3 images can be scrolled from left to right. So then I have left and right arrows on the activity and I set an onClickListener for both images to scroll left and right with ViewPager pager. The method is like
private void setOnClickArrows(final ViewPager pager){
ImageView rightArrow = (ImageView) view.findViewById(R.id.right);
ImageView leftArrow = (ImageView) view.findViewById(R.id.left);
rightArrow.setOnClickListener(new OnClickListener ()
#Override
public void onClick(View v) {
pager.setCurrentItem(pager.getCurrentItem() + 1);
}
});
leftArrow.setOnClickListener(new OnClickListener ()
#Override
public void onClick(View v) {
pager.setCurrentItem(pager.getCurrentItem() - 1);
}
});
}
This works perfectly. However, I was wondering how the ViewPager checks if the index is out of bounds and if I should do it?
Yes, it actually does. Refer to the source and have a look at the setCurrentItemInternal method (called by setCurrentItem()).
There are a few checks in place to avoid a crash, and among one of them is this, which avoids OOBExceptions:
if (item < 0) {
item = 0;
} else if (item >= mAdapter.getCount()) {
item = mAdapter.getCount() - 1;
}
Should you check yourself? Up to you. I wouldn't because those checks are trivial, so I wouldn't expect the checks to disappear.
I have an Activity containing a ViewPager that displays N fragments. Each fragment is showing the properties of an object from an ArrayList in my ViewPager's custom adapter (extends FragmentStatePagerAdapter).
The fragment has (among other things) a button that should remove the currently displayed fragment and scroll to the next one with setCurrentItem(position, true) so that if the user scrolls back, the previous item is gone. I do so by using something like this (simplified):
deleteButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
MyActivity parentActivity = (MyActivity)getActivity();
// First, scroll to next item (smoothly)
parentActivity.pager.setCurrentItem(parentActivity.pager.getCurrentItem()+1, true);
// Database stuff...
doSomeDBOperations();
// Method in Activity that removes the current object (I believe this method is working fine and yes, it calls notifyDataSetChanged())
parent.removeObject(currentObject);
}
});
This has the desired behavior as the object represented by the fragment whose delete button was pressed gets removed and the viewpager goes to the next page.
My problem is that the ViewPager doesn't scroll smoothly but rather "jumps instantly" to the next fragment. If I comment the removeObject() call, the smooth scroll works (but the item isn't removed). I believe it's has something to do with the removeObject() being called before the setCurrentItem() has finished the smooth scrolling animation?
Any ideas on how to fix this and achieve item removal + smooth scroll? If my assumption is correct, how can I make sure I get the smooth scroll to finish before removing the object?
EDIT 1:
My assumption seems correct. If I put the parent.removeObject(currentObject) inside
// ...inside the previously shown public void onClick(View v)...
confirm.postDelayed(new Runnable() {
#Override
public void run() {
// Method in Activity that removes the current object (I believe this method is working fine and yes, it calls notifyDataSetChanged())
parent.removeObject(currentObject);
}
}, 1000);
so that the removeObject() call waits for a second, it works as expected: scroll to the next item, remove the previous. But this is a very ugly workaround so I'd still like a better approach.
EDIT 2:
I figured out a possible solution (see below).
I ended up overriding the
public void onPageScrollStateChanged(int state)
method:
Whenever the user presses the delete button in the fragment, the listener sets a bool in the current item (flagging it for deletion) and scrolls to the next one.
When the onPageScrollStateChanged detects that the scroll state changed to ViewPager.SCROLL_STATE_IDLE (which happens when the smooth scroll ends) it checks if the previous item was marked for deletion and, if so, removes it from the ArrayList and calls notifyDataSetChanged().
By doing so, I've managed to get the ViewPager to smoothly scroll to the next position and delete the previous item when the "delete" button is pressed.
EDIT: Code snippet.
#Override
public void onPageScrollStateChanged(int state)
{
switch(state)
{
case ViewPager.SCROLL_STATE_DRAGGING:
break;
case ViewPager.SCROLL_STATE_IDLE:
int previousPosition = currentPosition - 1;
if(previousPosition < 0){
previousPosition = 0;
}
MyItem previousItem = itemList.get(previousPosition);
if(previousItem.isDeleted())
{
deleteItem(previousItem);
// deleteItem() Does some DB operations, then calls itemList.remove(position) and notifyDataSetChanged()
}
break;
case ViewPager.SCROLL_STATE_SETTLING:
break;
}
}
Have you tried ViewPager.OnPageChangeListener?
I would call removeObject(n) method in OnPageChangeListener.onPageSelected(n+1) method.
I did something different that works smoothly. The idea is to to remove the current item with animation (setting its alpha to 0), then translating horizontally the left or right item (with animation) to the now invisible item position.
After the animation is complete, I do the actual data removal and notfyDataSetChanged() call.
This remove() method I put inside a subclass of ViewPager
public void remove(int position, OnViewRemovedListener onViewRemovedListener) {
final int childCount = getChildCount();
if (childCount > 0) {
View toRemove = getChildAt(position);
int to = toRemove.getLeft();
final PagerAdapter adapter = getAdapter();
toRemove.animate()
.alpha(0)
.setDuration(getResources().getInteger(android.R.integer.config_shortAnimTime))
.setListener(new SimpleAnimatorListener() {
#Override
public void onAnimationEnd(Animator animation) {
if (childCount == 1) {
if (onViewRemovedListener != null) onViewRemovedListener.onRemoved(position, -1);
if (adapter!= null) adapter.notifyDataSetChanged();
}
}
})
.start();
if (childCount > 1) {
int newPosition = position + 1 <= childCount - 1 ? position + 1 : position - 1;
View replacement = getChildAt(newPosition);
int from = replacement.getLeft();
replacement.animate()
.setInterpolator(new DecelerateInterpolator())
.setDuration(getResources().getInteger(android.R.integer.config_mediumAnimTime))
.translationX(to - from)
.setListener(new SimpleAnimatorListener() {
#Override
public void onAnimationEnd(Animator animation) {
if (onViewRemovedListener != null) onViewRemovedListener.onRemoved(position, newPosition);
if (adapter!= null) adapter.notifyDataSetChanged();
}
})
.start();
}
}
}
public interface OnViewRemovedListener {
void onRemoved(int position, int newPosition);
}
I have a listview where pople can click on items. When they do, they increase height and show more information.
However, when clicking the bottom item, it is not visible to the user that the item height has increased and there is content if you scroll down.
Using e.g. following code in onItemClick does not solve the problem:
if (position == myItemsDataArrayList.size() - 1) {
if (data.ui_flags == "clicked") {
catalogListView.smoothScrollToPosition(position);
}
}
Implement this function in your if statement.
private void scrollMyListViewToBottom() {
myListView.post(new Runnable() {
#Override
public void run() {
// Select the last row so it will scroll into view...
myListView.setSelection(myListAdapter.getCount() - 1);
}
});
}
code by: https://stackoverflow.com/a/7032341/2197087
Working code solution was this:
catalogListView.post(new Runnable() {
#Override
public void run() {
catalogListView.setSelection(position_final);
}
});