How can insert cells to top in UITableView without moving to top offset

Question

We can insert cells to UITableView or UICollectionView and if the cells will be inserted to middle or bottom, we will feel smooth and stay at current offset. But when I insert at top, tableview or UICollectionView will move to Offset zero automatically, means I will not stay at current visible cells I want. How can I implement it, is it native feature or do we have to make some complex code? I see the FB messenger or Skype app, when scroll to top, new messages will be inserted without any change of current visible view. Anyone suggest to me a solution for this?

Answer 1

If you create a new simple project using master-Detail application you can see when you insert it doesn't scroll to top the content offset is only changed a bit (equal to new row height) even if you are in middle ,top or bottom it is inserting at the top . . it using simple code like

NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
    [self.tableView insertRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];

Now even if you don't want that little scrolling here is nice solution

//just need check if you already on the top of the tableview that may be first few rows depend on your row height 
if(self.tableView.contentOffset.y > ONE_OR_X_ROWS_HEIGHT_YOU_DECIDE
{

    self.delayOffset = self.tableView.contentOffset;
    self.delayOffset = CGPointMake(self.delayOffset.x, self.delayOffset.y+ insertedRowCount * ONE_ROW_HEIGHT);

    //insert your row here 

    [self.tableView setContentOffset:self.delayOffset animated:NO];    


}else
{
    //insert your row here

}