public override void OnScrolled(RecyclerView recyclerView, int dx, int dy)
{
base.OnScrolled(recyclerView, dx, dy);
//var visibleItemCount = recyclerView.ChildCount;
//var totalItemCount = recyclerView.GetAdapter().ItemCount;
//var pastVisiblesItems = LayoutManager.FindFirstVisibleItemPosition();
//if ((visibleItemCount + pastVisiblesItems) >= totalItemCount)
//{
// LoadMoreEvent(this, null);
// loading = true;
//}
totalItemCount = linearLayoutManager.ItemCount;
lastVisibleItem = linearLayoutManager.FindLastVisibleItemPosition();
//if (position >= getItemCount() - 1 && isMoreDataAvailable && !isLoading && loadMoreListener != null)
//{
// isLoading = true;
// loadMoreListener.onLoadMore();
//}
if (LoadMoreEvent != null && isMoreDataAvailable && !loading && totalItemCount <= (lastVisibleItem + visibleThreshold))
{
LoadMoreEvent(this, null);
loading = true;
}
}
public override void OnScrolled(RecyclerView recyclerView, int dx, int dy)
{
base.OnScrolled(recyclerView, dx, dy);
LinearLayoutManager linearLayoutManager = (LinearLayoutManager)recyclerView.GetLayoutManager();
if (!currentActivity.loading && linearLayoutManager.ItemCount == (linearLayoutManager.FindLastVisibleItemPosition() + 1))
{
new Handler().PostDelayed(() =>
{
if (currentActivity.loadTimes <= 5)
{
currentActivity.adapter.RemoveFooter();
currentActivity.loading = false;
currentActivity.adapter.AddItems(currentActivity.data);
currentActivity.adapter.AddFooter();
currentActivity.loadTimes++;
}
else
{
currentActivity.adapter.RemoveFooter();
var snackbar = Snackbar.Make(currentActivity.mRecyclerView,
currentActivity.GetString(Resource.String.no_more_data),
Snackbar.LengthShort);
snackbar.AddCallback(new MyCallback(currentActivity));
}
}, 1500);
currentActivity.loading = true;
}
}
public static bool CanRecyclerViewScroll(View view)
{
RecyclerView rv = (RecyclerView)view;
RecyclerView.LayoutManager lm = rv.GetLayoutManager();
int count = rv.GetAdapter().ItemCount;
int lastVisible = -1;
if (lm is LinearLayoutManager)
{
LinearLayoutManager llm = (LinearLayoutManager)lm;
lastVisible = llm.FindLastVisibleItemPosition();
}
else if (lm is GridLayoutManager)
{
GridLayoutManager glm = (GridLayoutManager)lm;
lastVisible = glm.FindLastVisibleItemPosition();
}
else
{
//throw new MaterialDialog.NotImplementedException("Material Dialogs currently only supports LinearLayoutManager and GridLayoutManager. Please report any new layout managers.");
throw new System.Exception("Material Dialogs currently only supports LinearLayoutManager and GridLayoutManager. Please report any new layout managers.");
}
if (lastVisible == -1)
{
return(false);
}
/* We scroll if the last item is not visible */
bool lastItemVisible = lastVisible == count - 1;
return(!lastItemVisible || rv.GetChildAt(rv.ChildCount - 1).Bottom > rv.Height - rv.PaddingBottom);
}
public static bool CanRecyclerViewScroll(RecyclerView view)
{
if (view == null || view.GetAdapter() == null || view.GetLayoutManager() == null)
{
return(false);
}
RecyclerView.LayoutManager lm = view.GetLayoutManager();
int count = view.GetAdapter().ItemCount;
int lastVisible;
if (lm is LinearLayoutManager)
{
LinearLayoutManager llm = (LinearLayoutManager)lm;
lastVisible = llm.FindLastVisibleItemPosition();
}
else
{
throw new InvalidOperationException("Material Dialogs currently only supports LinearLayoutManager. Please report any new layout managers.");
}
if (lastVisible == -1)
{
return(false);
}
bool lastItemVisible = lastVisible == count - 1;
return(!lastItemVisible ||
(view.ChildCount > 0 && view.GetChildAt(view.ChildCount - 1).Bottom > view.Height - view.PaddingBottom));
}
//当RecyclerView的滑动状态改变时触发
//滑动状态有3种，0：ScrollStateIdle手指离开屏幕1ScrollStateDragging：手指触碰屏幕2ScrollStateSetting
public override void OnScrollStateChanged(RecyclerView recyclerView, int newState)
{
base.OnScrollStateChanged(recyclerView, newState);
System.Diagnostics.Debug.Write("test", "newState:" + newState);
int state = recyclerView.ScrollState;
if (state == RecyclerView.ScrollStateIdle)
{
int lastVisibleItemPosition = _linearLayoutManager.FindLastVisibleItemPosition();
if (lastVisibleItemPosition + 1 == _adapter.ItemCount)
{
System.Diagnostics.Debug.Write("test", "loadding已经完成" + state);
_InsertDataEvent();
}
}
}
public override void OnScrolled(RecyclerView recyclerView, int dx, int dy)
{
base.OnScrolled(recyclerView, dx, dy);
LinearLayoutManager layoutManager = (LinearLayoutManager)recyclerView.GetLayoutManager();
if (layoutManager.FindLastVisibleItemPosition() + threshold > collection.Count && dy > 0)
{
LoadMore(threshold);
}
}
public override void OnScrolled(RecyclerView recyclerView, int dx, int dy)
{
base.OnScrolled(recyclerView, dx, dy);
var totalItemCount = recyclerView.GetAdapter().ItemCount;
var lastVisibleItemPosition = LayoutManager.FindLastVisibleItemPosition();
if (totalItemCount == (lastVisibleItemPosition + 1) && LoadMoreEvent != null)
{
LoadMoreEvent(this, null);
}
}
public override void OnScrollStateChanged(RecyclerView recyclerView, int newState)
{
base.OnScrollStateChanged(recyclerView, newState);
try
{
if (newState == (int)Android.Widget.ScrollState.Idle)
{
//if (XRecyclerView.Thumbnail != null)
// XRecyclerView.Thumbnail.Visibility = ViewStates.Visible;
//if (XRecyclerView.PlayControl != null)
// XRecyclerView.PlayControl.Visibility = ViewStates.Visible;
XRecyclerView.PlayVideo(!recyclerView.CanScrollVertically(1));
}
else
{
var startPosition = LayoutManager.FindFirstVisibleItemPosition();
var endPosition = LayoutManager.FindLastVisibleItemPosition();
var startPositionVideoHeight = XRecyclerView.GetVisibleVideoSurfaceHeight(startPosition);
var endPositionVideoHeight = XRecyclerView.GetVisibleVideoSurfaceHeight(endPosition);
var targetPosition = startPositionVideoHeight > endPositionVideoHeight;
if (endPositionVideoHeight - 230 > startPositionVideoHeight)
{
if (XRecyclerView.VideoPlayer.PlayWhenReady)
{
XRecyclerView.VideoPlayer.PlayWhenReady = false;
}
}
if (startPositionVideoHeight <= 60)
{
if (XRecyclerView.Thumbnail != null)
{
XRecyclerView.Thumbnail.Visibility = ViewStates.Visible;
}
if (XRecyclerView.PlayControl != null)
{
XRecyclerView.PlayControl.Visibility = ViewStates.Visible;
}
}
}
}
catch (Exception e)
{
Console.WriteLine(e);
}
}
public override void OnScrolled(RecyclerView recyclerView, int dx, int dy)
{
base.OnScrolled(recyclerView, dx, dy);
//var visibleItemCount = recyclerView.ChildCount;
var totalItemCount = recyclerView.GetAdapter().ItemCount;
var lastVisibleItemPosition = LayoutManager.FindLastVisibleItemPosition();
//var pastVisiblesItems = LayoutManager.FindFirstVisibleItemPosition();
Log.Debug("test", "totalItemCount =" + totalItemCount + "-----" + "lastVisibleItemPosition =" + lastVisibleItemPosition);
if (totalItemCount == (lastVisibleItemPosition + 1) && LoadMoreEvent != null)
{
LoadMoreEvent(this, null);
}
}
public override void OnScrolled(RecyclerView recyclerView, int dx, int dy)
{
base.OnScrolled(recyclerView, dx, dy);
LinearLayoutManager layoutManager = (LinearLayoutManager)recyclerView.GetLayoutManager();
int firstVisible = layoutManager.FindFirstVisibleItemPosition();
int visibleCount = Math.Abs(firstVisible - layoutManager.FindLastVisibleItemPosition());
int itemCount = recyclerView.GetAdapter().ItemCount;
if (firstVisible != lastFirstVisible ||
visibleCount != lastVisibleCount ||
itemCount != lastItemCount)
{
scrollListener.OnScroll(null, firstVisible, visibleCount, itemCount);
lastFirstVisible = firstVisible;
lastVisibleCount = visibleCount;
lastItemCount = itemCount;
}
}
public override void OnDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state)
{
base.OnDrawOver(c, parent, state);
int itemCount = parent.GetAdapter().ItemCount;
// center horizontally, calculate width and subtract half from center
float totalLength = mIndicatorItemLength * itemCount;
float paddingBetweenItems = Math.Max(0, itemCount - 1) * mIndicatorItemPadding;
float indicatorTotalWidth = totalLength + paddingBetweenItems;
float indicatorStartX = (parent.Width - indicatorTotalWidth) / 2F;
float indicatorPosY = parent.Height - mIndicatorHeight / 2F;
drawInactiveIndicators(c, indicatorStartX, indicatorPosY, itemCount);
// find active page (which should be highlighted)
LinearLayoutManager layoutManager = (LinearLayoutManager)parent.GetLayoutManager();
int activePosition = layoutManager.FindLastVisibleItemPosition();
if (activePosition == RecyclerView.NoPosition)
{
return;
}
// find offset of active page (if the user is scrolling)
View activeChild = layoutManager.FindViewByPosition(activePosition);
int left = activeChild.Left;
int width = activeChild.Width;
// on swipe the active item will be positioned from [-width, 0]
// interpolate offset for smooth animation
float progress = mInterpolator.GetInterpolation(left * -1 / (float)width);
drawHighlights(c, indicatorStartX, indicatorPosY, activePosition, progress, itemCount);
}
/// <summary>
/// This method calculates the current scroll position and its offset to help new attached
/// recyclerView on window at that position and offset
/// </summary>
/// <seealso cref="GetScrollPosition()"/>
/// <seealso cref="GetScrollPositionOffset()"/>
private void RenewScrollPosition(RecyclerView recyclerView)
{
LinearLayoutManager layoutManager = (LinearLayoutManager)recyclerView.GetLayoutManager();
mScrollPosition = layoutManager.FindFirstCompletelyVisibleItemPosition();
// That means there is no completely visible Position.
if (mScrollPosition == -1)
{
mScrollPosition = layoutManager.FindFirstVisibleItemPosition();
// That means there is just a visible item on the screen
if (mScrollPosition == layoutManager.FindLastVisibleItemPosition())
{
}
else
{
// in this case we use the position which is the last & first visible item.
// That means there are 2 visible item on the screen. However, second one is not
// completely visible.
mScrollPosition = mScrollPosition + 1;
}
}
mScrollPositionOffset = layoutManager.FindViewByPosition(mScrollPosition).Left;
}
void UpdateProgressBar(int position, long progress)
{
queue[position].progress = (int)(progress * 100);
DownloadQueue.instance?.RunOnUiThread(() =>
{
LinearLayoutManager LayoutManager = (LinearLayoutManager)DownloadQueue.instance?.ListView?.GetLayoutManager();
if (LayoutManager != null && position >= LayoutManager.FindFirstVisibleItemPosition() && position <= LayoutManager.FindLastVisibleItemPosition())
{
View view = DownloadQueue.instance.ListView.GetChildAt(position - LayoutManager.FindFirstVisibleItemPosition());
DownloadHolder holder = (DownloadHolder)DownloadQueue.instance.ListView.GetChildViewHolder(view);
holder.Progress.Progress = (int)(progress * 100);
}
});
if (queue.Count == 1)
{
SetNotificationProgress((int)(progress * 100));
}
}
public override void OnScrolled(RecyclerView recyclerView, int dx, int dy)
{
pref = PreferenceManager.GetDefaultSharedPreferences(Application.Context);
LinearLayoutManager linearLayoutManager = (LinearLayoutManager)recyclerView.GetLayoutManager();
int lastVisibleItem = linearLayoutManager.FindLastVisibleItemPosition();
int totalItemCount = recyclerView.GetAdapter().ItemCount;
if (!IsLoading && totalItemCount <= (lastVisibleItem + visibleThreshold))
{
// End has been reached
// Do something
var currPrefPage = pref.GetString("CurrentPage", string.Empty);
if (!String.IsNullOrEmpty(currPrefPage))
{
if (Int32.Parse(currPrefPage) > 0)
{
currentPage++;
}
else
{
currentPage = 2;
}
}
else
{
currentPage++;
}
var editor = pref.Edit();
editor.PutString("CurrentPage", currentPage.ToString());
editor.Apply();
IsLoading = true;
Task.Factory.StartNew(async() => {
try{
var newPostList = new List <Post>();
await WebClient.LoadPosts(newPostList, currentPage);
(recyclerView.GetAdapter() as PostViewAdapter)._Posts.AddRange(newPostList);
//recyclerView.GetAdapter().HasStableIds = true;
_messageShown = false;
Application.SynchronizationContext.Post(_ => { recyclerView.GetAdapter().NotifyDataSetChanged(); }, null);
//recyclerView.GetAdapter().NotifyItemRangeInserted(recyclerView.GetAdapter().ItemCount,newPostList.Count);
}catch (Exception ex) {
//Insights.Report(ex,new Dictionary<string,string>{{"Message",ex.Message}},Insights.Severity.Error);
var text = ex.Message;
if (!_messageShown)
{
Application.SynchronizationContext.Post(_ => {
Toast.MakeText(Application.Context, "При загрузке данных произошла ошибка", ToastLength.Short).Show();
}, null);
_messageShown = true;
}
}
IsLoading = false;
});
}
}
private int GetLastVisibleItemPosition()
{
//return (mLayoutManager as LinearLayoutManager).FindLastVisibleItemPosition();
return(mLayoutManager.FindLastVisibleItemPosition());
}
public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
rootView = (LinearLayout)inflater.Inflate(Resource.Layout.reading_and_writing_fragment, container, false);
mRecyclerView = rootView.FindViewById <RecyclerView>(Resource.Id.recyclerView);
mRecyclerView.HasFixedSize = true;
mLayoutManager = new LinearLayoutManager(Activity);
mRecyclerView.SetLayoutManager(mLayoutManager);
mAdapter = new RecyclerViewAdapter(App.db.GetAllImages(), Activity);
mRecyclerView.SetAdapter(mAdapter);
if (App.CurrentImagePossition != -1)
{
if (!(mLayoutManager.FindFirstVisibleItemPosition() <= App.CurrentImagePossition && mLayoutManager.FindLastVisibleItemPosition() >= App.CurrentImagePossition))
{
Activity.RunOnUiThread(() =>
{
mLayoutManager.ScrollToPositionWithOffset(App.CurrentImagePossition, 20);
});;
}
//StartPostponedEnterTransition();
}
else
{
//StartPostponedEnterTransition();
}
mAdapter.ItemClick += delegate
{
var view = mRecyclerView.FindViewHolderForAdapterPosition(mAdapter.ClickedPosition) as RecyclerViewHolder;
var tmp = view.Slika.TransitionName;
GuessingImageFragment gif = new GuessingImageFragment(mAdapter.clickedImage.Id);
//gif.SharedElementEnterTransition = new AutoTransition();
//gif.EnterTransition = new Fade();
//setExitTransition(new Fade());
Activity.FragmentManager.BeginTransaction()
.Replace(App.fragmentContainer.Id, gif, "guessing")
.AddSharedElement(view.Slika, mAdapter.clickedImage.Name)
.AddToBackStack(null)
.Commit();
App.CurrentFragment = gif;
};
return(rootView);
}
public override void MeasureChildWithMargins(Android.Views.View child, int widthUsed, int heightUsed)
{
base.MeasureChildWithMargins(child, widthUsed, heightUsed);
// If has fixed width is true, than calculation of the column width is not necessary.
if (mTableView.HasFixedWidth())
{
return;
}
int position = GetPosition(child);
ColumnLayoutManager childLayoutManager =
(ColumnLayoutManager)((CellRecyclerView)child).GetLayoutManager();
// the below codes should be worked when it is scrolling vertically
if (mCellRecyclerView.ScrollState != RecyclerView.ScrollStateIdle)
{
if (childLayoutManager.IsNeedFit())
{
// Scrolling up
if (mLastDy < 0)
{
Log.Error(LogTag, position + " fitWidthSize all vertically up");
FitWidthSize(true);
}
else
{
// Scrolling down
Log.Error(LogTag, position + " fitWidthSize all vertically down");
FitWidthSize(false);
}
// all columns have been fitted.
childLayoutManager.ClearNeedFit();
}
// Set the right initialPrefetch size to improve performance
childLayoutManager.InitialPrefetchItemCount = childLayoutManager.ChildCount;
}
else
{
// That means,populating for the first time like fetching all data to display.
// It shouldn't be worked when it is scrolling horizontally ."getLastDx() == 0"
// control for it.
if (childLayoutManager.GetLastDx() == 0 &&
mCellRecyclerView.ScrollState == RecyclerView.ScrollStateIdle)
{
if (childLayoutManager.IsNeedFit())
{
mNeedFit = true;
// all columns have been fitted.
childLayoutManager.ClearNeedFit();
}
if (mNeedFit)
{
// for the first time to populate adapter
if (mRowHeaderLayoutManager.FindLastVisibleItemPosition() == position)
{
FitWidthSize2(false);
Log.Error(LogTag, position + " fitWidthSize populating data for the first time");
mNeedFit = false;
}
}
}
}
}
public override bool Fling(int velocityX, int velocityY)
{
if (ItemCount < 1)
{
return(true);
}
FlingEventArgs flingEventArgs;
if (velocityX > 0)
{
flingEventArgs = new FlingEventArgs(FlingDirection.Right, CurrentItem);
if (CurrentItem == ItemCount - 1)
{
return(true);
}
}
else
{
flingEventArgs = new FlingEventArgs(FlingDirection.Left, CurrentItem);
}
if (BeforeFling != null)
{
BeforeFling(this, flingEventArgs);
}
LinearLayoutManager linearLayoutManager = (LinearLayoutManager)GetLayoutManager();
//these four variables identify the views you see on screen.
int lastVisibleView = linearLayoutManager.FindLastVisibleItemPosition();
int firstVisibleView = linearLayoutManager.FindFirstVisibleItemPosition();
View firstView = linearLayoutManager.FindViewByPosition(firstVisibleView);
View lastView = linearLayoutManager.FindViewByPosition(lastVisibleView);
//these variables get the distance you need to scroll in order to center your views.
//my views have variable sizes, so I need to calculate side margins separately.
//note the subtle difference in how right and left margins are calculated, as well as
//the resulting scroll distances.
int leftMargin = (screenWidth - lastView.Width) / 2;
int rightMargin = (screenWidth - firstView.Width) / 2 + firstView.Width;
int leftEdge = lastView.Left;
int rightEdge = firstView.Right;
int scrollDistanceLeft = leftEdge - leftMargin;
int scrollDistanceRight = rightMargin - rightEdge;
//if(user swipes to the left)
if (velocityX > 0)
{
CurrentItem = lastVisibleView - 1;
SmoothScrollBy(scrollDistanceLeft, 0);
}
else
{
CurrentItem = firstVisibleView - 1;
SmoothScrollBy(-scrollDistanceRight, 0);
}
if (OnFling != null)
{
OnFling(this, flingEventArgs);
}
return(true);
}
