I have a UITableView and in its -tableView:didSelectRowAtIndexPath: method I want to change the appearance of two cells (the one that has just been selected and the one that was selected before). I do that with this method:
// reload both rows to change appearance
if (![indexPath isEqual:activeIndexPath]) {
[self.tableView reloadRowsAtIndexPaths:[NSArray arrayWithObjects:activeIndexPath, indexPath, nil]
withRowAnimation:UITableViewRowAnimationAutomatic];
}
With the parameter UITableViewRowAnimationAutomatic set it works great: the corresponding rows are updated with a smooth transition. But I want those two rows to update immediately without an animation.
I thought that UITableViewRowAnimationNone would do the trick but if I use that constant for the row animation the cells are not being updated at all
Related
I'm making a UIViewController to manage a messaging screen. I'm doing this using a UITableView and some custom cells.
To make things simpler, each cell contains:
Its chat "bubble" (a UIView subclass)
Its chat text (a UILabel)
A timestamp header label (which might be hidden)
A bottom footer label (for "Sending...", "Delivered", etc.; also might be hidden)
Because of performance concerns, I am not using auto-sizing of cell heights, but caching cell heights into an NSMutableDictionary.
When the user sends or receives a new message, I want the following to occur:
The current last message cell is reloaded, hiding its bottom label, if needed.
The new last message cell is appended at the bottom of the UITableView.
The UITableView is scrolled so that the new last cell is visible.
I can get it to where the end state of the screen is as desired, but the animations in between are really kinda funky. I have tried a whole lot of different approaches to get the animations to behave. Basically, it seems like some major reloading is happening, even though the only cell that could possibly change its height is the last cell (prior to the insertion of the new cell). Plus, I'd like to have the last cell simply "appear" in place without animation. If it does, it should be off-screen, and then I should be able to animate it on-screen.
Here's my current "user sent a new message" method:
- (IBAction)sendButtonPressed {
//Creation of the new message, into 'message' variable
[self.messages addObject:message];
int thisIndex = (int)self.messages.count - 1;
NSIndexPath *this = [NSIndexPath indexPathForRow:thisIndex inSection:0];
int prevIndex = (int)self.messages.count - 2;
NSIndexPath *prev = [NSIndexPath indexPathForRow:prevIndex inSection:0];
[self removeCachedHeightForIndex:prevIndex];
[self.tableView beginUpdates];
[self.tableView reloadRowsAtIndexPaths:#[prev] withRowAnimation:UITableViewRowAnimationNone];
[self.tableView insertRowsAtIndexPaths:#[this] withRowAnimation:UITableViewRowAnimationTop];
[CATransaction setCompletionBlock:^{
[self scrollToBottomAnimated:YES];
}];
[self.tableView endUpdates];
}
This appears to reload the last several cells in the UITableView. Or, at least, every cell that is visible when this is called seems to be animated in some way. Only the cell at prev is actually changing in any way.
Longterm, I might pull out the header and footer labels into different cells, but is there a way to fix this animation glitch as-is?
I have UITableView with variable height custom cells and multiple sections which are not fixed, i am trying to implement load more functionality while user reach at first cell.
After fetching data i am arranging records into NSMutableArray which contains multi-dimensional array to store data section vice.
My problem is when i load more data i don't have idea about how many sections and how many rows in each section comes. So i can not add fix values to move my UITableView at particular position using methods like scrollToRowAtIndexPath or scrollRectToVisible
So every time after getting new record i called reloadData to update my number Of Sections and number Of Rows In Each Section, which also move control to first row of UITableView. I want to be present at current viewing cell not at first cell.
I have also tried answers at reloadData() of UITableView with Dynamic cell heights causes jumpy scrolling this question but that are not helping me.
Don't use reloadData if you want to stay at the same position. Use reloadRowsAtIndexPaths or insertRowsAtIndexPaths or reloadSections instead.
To refresh modified rows with animation:
[self.tableView beginUpdates];
[self.tableView reloadRowsAtIndexPaths:#[indexPathOfYourModifiedCell] withRowAnimation: UITableViewRowAnimationAutomatic];
[self.tableView endUpdates];
To add rows with animation (number of rows is automatically increased):
[self.tableView beginUpdates];
[self.tableView insertRowsAtIndexPaths:#[indexPathOfYourNewCell] withRowAnimation: UITableViewRowAnimationAutomatic];
[self.tableView endUpdates];
Without animation (untested):
[UIView performWithoutAnimation:^{
[self.tableView beginUpdates];
[self.tableView insertRowsAtIndexPaths:#[indexPathOfYourNewCell] withRowAnimation:UITableViewRowAnimationNone];
[self.tableView endUpdates];
}];
Apple documentation: description here
Here is my program. I want to create a simple list of items that display a number. When the rows are tapped the number will increment by one.
EDIT: Is it proper to change the UI of a row in the didSelectRowAtIndexPath function?
I created a UIViewController in Xcode 5 through a storyboard and it does everything right except I can't seem to stop the [tableView reloadData] from deselecting my row after being tapped. Specifically, I want the row to turn gray and then fade out normally.
I have tried selecting the row and then deselecting the row programatically after calling [tableView reloadData], but it doesn't work.
I know that if I was using UITableViewController that I could just call [self setClearsSelectionOnViewWillAppear:NO], but I'm not.
Is there a similar property I can set for UIViewController?
Here is the code:
[tableView beginUpdates];
[counts replaceObjectAtIndex: row withObject: [NSNumber numberWithInt:newCount]];
[tableView reloadData];
[tableView endUpdates];
I feel I may not be describing what is going on. I have a row that uses UITableViewCellStyle2, which displays a label to the left and right. On the right aligned text is a number that increments each time the row is tapped. Simply updating the data structure does not solve the problem. I need to update it visually. I don't need or want to replace the row, unless I have too. I just want to update the right-aligned text field AND keep the row from being deselected immediately without animation. I can do one or the other, but not both.
Is there a way to just update the right-aligned text field while still staying true to the MVC model?
Remove the [tableView reloadData]; from the code. It should not be called in the methods that insert or delete rows, especially within an animation block implemented with calls to beginUpdates and endUpdates .
Call reloadData method to reload all the data that is used to construct the table, including cells, section headers and footers, index arrays, and so on. For efficiency, the table view redisplays only those rows that are visible. It adjusts offsets if the table shrinks as a result of the reload. The table view's delegate or data source calls this method when it wants the table view to completely reload its data.
[tableView beginUpdates];
[counts replaceObjectAtIndex: row withObject: [NSNumber numberWithInt:newCount]];
[tableView endUpdates];
See the developer.apple section - reloadData
If you want to keep the selection after reload, the easy way is
NSIndexPath *selectedRowIndexPath = [tableView indexPathForSelectedRow];
[tableView reloadData];
[tableView selectRowAtIndexPath:selectedRowIndexPath animated:NO scrollPosition:UITableViewScrollPositionNone];
I have a dynamic UITableView. On the first row of the first section I have a segmentedControll (everything with prototype cells, subclassing and delegating to the UITableViewController). With this segmented control I want an additional row to appear on the very same section. What I do is to have a conditional on the numberOfRowsInSection and then when the SegmentedControl is tapped it triggers the following:
if (cellPath.section==0 && cellPath.row==1) {
if (segmentedCell.segmentControl.selectedSegmentIndex==0) {
reverse=NO;
[self.tableView reloadSections:[NSIndexSet indexSetWithIndex:0] withRowAnimation:UITableViewRowAnimationAutomatic];
}else if (segmentedCell.segmentControl.selectedSegmentIndex==1){
reverse=YES;
[self.tableView reloadSections:[NSIndexSet indexSetWithIndex:0] withRowAnimation:UITableViewRowAnimationAutomatic];
}
}
it somehow works, but the problem is that the SegmentedControl also gets reloaded at its initial state and you can inmagine the rest.
Any idea on how to workaround this? I've also tried reloadRowsAtIndex..., but doesn't work (I did put the begin/end ).
Thanks in advance!
When you reload a table the cell are "reused". So each cell will not store state but relies on another class (delegate) to hold the state. So if you wish to maintain the state on your segmented control, then store its value in the delegate for your table view and then ensure you set that value to your segmented control in you cellForRowAtIndexPath each time for its index path.
Ok, I'm stuck. This is an extension of a previous post of mine. Here is what I am trying to do.
I have an Edit button on a navigation bar that when pressed adds a cell at the beginning of my one section table view. The purpose of this cell if to allow the use to add new data to the table; thus it's editing style is Insert. The remaining cells in the table are configured with an editing style of Delete.
Here is my setediting method:
- (IBAction) setEditing:(BOOL)isEditing animated:(BOOL)isAnimated
{
[super setEditing:isEditing animated:isAnimated];
// We have to pass this to tableView to put it into editing mode.
[self.tableView setEditing:isEditing animated:isAnimated];
// When editing is begun, we are adding and "add..." cell at row 0.
// When editing is complete, we need to remove the "add..." cell at row 0.
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
NSArray* path = [NSArray arrayWithObject:indexPath];
// fill paths of insertion rows here
[self.tableView beginUpdates];
if( isEditing )
[self.tableView insertRowsAtIndexPaths:path withRowAnimation:UITableViewRowAnimationBottom];
else
[self.tableView deleteRowsAtIndexPaths:path withRowAnimation:UITableViewRowAnimationBottom];
[self.tableView endUpdates];
// We nee to reload the table so that the existing table items will be properly
// indexed with the addition/removal of the the "add..." cell
[self.tableView reloadData];
}
I am accounting for this extra cell in my code, except I now have two index paths = [0,0] - the new cell and the old original first cell in the table. If I add a call to reload the table view cell in setEditing, the cells are re-indexed, but now my table view is no longer animated.
I want my cake and eat it too. Is there another way to accomplish what I am trying to do and maintain animation?
--John
You can do what you want but you need to keep your data source consistent with the table. In other words, When the table is reloaded, tableView:cellForRowAtIndexPath and the other UITableViewDataSource and UITableViewDelegate methods responsible for building the table should return the same cells depending on editing state that you are adding/removing in setEditing:antimated:.
So, when you insert/delete a cell in setEditing:animated: you need to also make sure your data source reflects the same change. This can be tricky if you are adding a special cell to the beginning of a section but the rest of the data is from an array. One way to do this is while reloading the table, if editing, make row 0 the add cell and use row-1 for your array index for subsequent cells. If you do that you'd also need to add one to tableView:numberOfRowsInSection: to account for the extra cell.
Another way would be to have a section for the add cell and it would have 0 rows when not editing, 1 row otherwise and you return the appropriate cell. This will also require you to configure your table and cell(s) appropriate depending on how you want things to look.