I have collection view, and have logic to delete cells from it. However, when cell is removed, next cell is appeared instantly on deleted cell place. Is there a way to add animation for deletion, for example, for 0.5 sec change opaque of cell, or something similar? There is a method i use for delete cell:
-(void)aMethod:(UIButton*)sender{
[self.viewModel deleteAt:[sender tag]];
[self.myCollectionView reloadData];
}
You have to use:
[UIView performWithoutAnimation:^{
[self.myCollectionView reloadData];
}];
Related
I have a UITableView and when the user swipes on one of the cells he can delete the cell (delete the object from the array).
But for example, when the user swipes on a cell in the middle of the table the animation is made on the last cell (the one on the bottom) like in this video:
https://vid.me/D0pi
Here is the code for this deletion:
//Removing cell from "AroundersTableView"(UITableView) with UITableViewRowAnimationLeft
[self.AroundersTableView beginUpdates];
[self.Arounders removeObjectAtIndex:cellRowToDelete];
[self.AroundersTableView deleteRowsAtIndexPaths:#[[NSIndexPath indexPathForRow:cellRowToDelete inSection:0]] withRowAnimation:UITableViewRowAnimationLeft];
[self.AroundersTableView endUpdates];
//Saving Arounders
[self saveArounders];
//Creating "newTableFrame"(CGRect) and setting it to current "AroundersTableView"'s frame will one less cell
CGRect newTableFrame=self.AroundersTableView.frame;
newTableFrame.origin.y+=44;
//Animating "AroundersTableView" to the new frame
[UIView animateWithDuration:0.5 animations:^{
self.AroundersTableView.frame=newTableFrame;
}];
//ReConfiguring "AroundersTableView"(UITableView) height
[self performSelector:#selector(configureTableViewsHeight) withObject:nil afterDelay:0.5];
//Reloading "AroundersTableView"(UITableView) data
[self.AroundersTableView reloadData];
Note: configureTableViewsHeight is just a method the makes the tableView height to be the cell.height*Arounders.count (cells height * number of cells).
I have no idea why it's happening.
Why is it? How can I make the animation on the correct cell (the all the cells above it are going down and hiding the red part)?
Thank you!
Is there a way to slow down the row insertion/deletion animation ?
In my particular case, I'm expanding/colapsing a cell by adding/removing rows below my cell and I'd like to slow the animation a little bit.
I'm using the below tricks to animate insert/delete the table view cells in my project, which works fine.
you can try this out. Happy coding!!!
// Here you can change the animation duration based on ur needs
NSTimeInterval animationDuration = 2.0f;
[UIView animateWithDuration:animationDuration animations:^{
// Disable the user interaction to the view if needed, otherwise user may interact with table view.
//view.userInteractionEnabled = NO;
[tableview beginUpdates];
// insert object to table view data source
//[yourArray insertObject:#"Some object" atIndex:some indexpath];
// Perform insert animation
//[tableview insertRowsAtIndexPaths:[NSArray arrayWithObject:someindexpath] withRowAnimation:UITableViewRowAnimationRight];
[tableview endUpdates];
} completion:^(BOOL finished) {
NSLog(#"Animation done");
// Enable the user interaaction now
//view.userInteractionEnabled = YES;
}];
Try to add/remove rows as following :
[_tableView beginUpdates];
// your add/remove func
[_tableView endUpdates];
Do UI changes for Tableview like above to reduce slow behaviour.
Hope it helps..
I'm facing this problem and I've been trying to figure out how to fix it but without success.
I have a table view with cells that contain an image which I still don't know which height is going to be. I created an outlet to the height constraint of the imageView and I'm downloading the image asynchronous with PinRemoteImage (I can use SDWebImage too but I think it's buggy in iOS 9). Inside the blocks is where I assign the new constant for the height constraint and then I do a layout update.
The cell never updates, the only way I can see the image correctly is scrolling down and then up (when the tableview repaints the cell)
__weak typeof(UITableView*) weakTable = tableView;
__weak typeof(NSIndexPath*) index = indexPath;
[cell.commentImageView pin_setImageFromURL:[[CTImageHelper sharedInstance] resizedImageURLConverterFromStringWithPrefix:comment.image.completePath andOptions:optionsString] completion:^(PINRemoteImageManagerResult *result) {
CommentTableViewCell *cellToUpdate = [weakTable cellForRowAtIndexPath:index];
cellToUpdate.heightSize = [NSNumber numberWithFloat:result.image.size.height/2];
cellToUpdate.commentImageViewHeightConstraint.constant = result.image.size.height/2;
[cellToUpdate setNeedsLayout];
}];
This is the code for setting the table view row height automatically
self.postTableView.estimatedRowHeight = 244.0;
self.postTableView.rowHeight = UITableViewAutomaticDimension;
And an image about the cell constraints:
Any ideas about what am I doing wrong? Thanks!
Put layoutIfNeeded just after setNeedsLayout
[cellToUpdate setNeedsLayout];
[cellToUpdate layoutIfNeeded];
// and then tell the tableView to update.
[weakTable beginUpdates];
[weakTable endUpdates];
// then scroll to the current indexPath
[weakTable scrollToRowAtIndexPath:indexPath
atScrollPosition:UITableViewScrollPositionNone
animated:NO];
Update [weakTable beginUpdates];[weakTable endUpdates]; might crash if call it more than once at a time. you need to make sure there is no colision between them.
You may also try just reloading the cell itself.
[cellToUpdate setNeedsLayout];
[cellToUpdate layoutIfNeeded];
[weakTable reloadRowsAtIndexPaths:[indexPath] withRowAnimation:UITableViewRowAnimationNone];
You should call layoutIfNeeded after calling setNeedsLayout to actually trigger the layout.
You need to tell the tableview that the height has changed on it's cells by triggering an empty update, apart from the setNeedsLayout and layoutIfNeeded:
[tableView beginUpdates];
[tableView endUpdates];
I am having a problem with the animation that UITableView provides when deleting and inserting a cell at the same time.
I have a list of cells lets call them questions. When one question is tapped it should add a cell beneath itself to display the answer to that question. If another answer is already being displayed that answer should be removed from the table.
The issue arises when the cell being inserted is very tall. If it is so tall that it's eventual bounds encroach into the space that the cell to be deleted takes up then during the animation we see the through the answer cell that we are deleting to see the cell that is being added
(see link to video of problem)
the is what my code looks like to move around the cells in the table view
[tableView beginUpdates];
if (deleteIndex) {
[tableView deleteRowsAtIndexPaths:#[deleteIndex] withRowAnimation:UITableViewRowAnimationTop];
}
if (addIndex) {
[tableView insertRowsAtIndexPaths:#[addIndex] withRowAnimation:UITableViewRowAnimationTop];
}
[tableView endUpdates];
I have tried
[tableView beginUpdates];
if (deleteIndex) {
[tableView deleteRowsAtIndexPaths:#[deleteIndex] withRowAnimation:UITableViewRowAnimationTop];
}
[tableView endUpdates];
//do stuff to update data source
[tableView beginUpdates];
if (addIndex) {
[tableView insertRowsAtIndexPaths:#[addIndex] withRowAnimation:UITableViewRowAnimationTop];
}
[tableView endUpdates];
But because there's no callback confirming that the table view did complete the first set update before starting the second block pretty much the same problem occurs. I know I could use perform selector with delay, but this seems like a bandaid.
Second I tried to encompass the animation in a block like this
[UIView animateWithDuration:0.0 animations:^{
[tableView beginUpdates];
if (deleteIndex) {
[tableView deleteRowsAtIndexPaths:#[deleteIndex] withRowAnimation:UITableViewRowAnimationTop];
}
[tableView endUpdates];
//do stuff to update data source
} completion:^(BOOL finished) {
[tableView beginUpdates];
if (addIndex) {
[tableView insertRowsAtIndexPaths:#[addIndex] withRowAnimation:UITableViewRowAnimationTop];
}
[tableView endUpdates];
}];
Again, because the completion block is fired after we call endUpdates not after the updates actually complete this does not resolve the use.
I also went into storyboard to be sure that clip subviews to bounds is selected for the cells. Again, this does not resolve the issue because we are not seeing a subview of the cell expand beyond it's expected height.
Looking closer at the animation by slowing it down it looks like apple inserts the cell to be added under the cells that won't be changed in the table and then moves the cells that will remain into their new positions. As a result the cell that was deleted becomes a transparent window where we see what they are actually doing under the hood.
The right approach would be to first remove the old answer and then after the animation is over add the new answer. There is a UITableViewDelegate method that is triggered after the cell animation is complete.
tableView:didEndDisplayingCell:forRowAtIndexPath:
Inserting the new answer row within this delegate method will result in the correct animation.
There are a few details to keep in mind- You'll need some logic to ensure that the correct cell height is returned and that the correct number of expected rows in the section is returned. Those data source methods are called after we remove our old answer in and again when we add the new one when we call
endUpdates
on the table view
Using anything other than UITableViewRowAnimationTop results in some strange animation behavior. This is because the content view of the cell is not what is being animated.
i solve same problem in my project by hide control like:
in ~cell.m have
(void)setSelected:(BOOL)selected animated:(BOOL)animated;
{
if(selected == NO)
{
self.selectedView.hidden = YES;
self.descriptionLabel.hidden = YES;
}
else
{
self.selectedView.hidden = NO;
self.descriptionLabel.hidden = NO;
}
}
may it still helpful
I have a table with shadows above the top and below the bottom cell (using Matt Gallagher's solution here: http://cocoawithlove.com/2009/08/adding-shadow-effects-to-uitableview.html). These are added in the layoutSubviews method of the UITableView class extension.
I dynamically add and delete cells below each main cell (these provide additional data) - let's call these "detail" cells. There is only one ever open at a time. When deleting the "detail cell" beneath the last main cell, as the animation begins, the shadow flicks upwards to the last cell (above the detail cell). It does this because the layoutSubview methods considers the last cell of the table to have changed the moment the animation for deleteRowsAtIndexPaths begins (rather than when the animation ends).
So, in essence, I need a way to keep the shadow below the detail cell as its being deleted. Not sure of the best way to do this. If the UITableView no longer considers that cell to be the last cell, then I am not sure even how to get the cell (since the UITableView gets the cell thus):
NSIndexPath *lastRow = [indexPathsForVisibleRows lastObject];
if ([lastRow section] == [self numberOfSections] - 1 &&
[lastRow row] == [self numberOfRowsInSection:[lastRow section]] - 1)
{
//adds shadow below it here
}
So even trapping the start of the animation is not much use if the UITableView still thinks the main cell above the "detail" cell is the "lastObject".
Thanks for any ideas.
Try this
[CATransaction begin];
[tableView beginUpdates];
//...
[CATransaction setCompletionBlock: ^{
// Code to be executed upon completion
}];
[tableView deleteRowsAtIndexPaths: indexPaths
withRowAnimation: UITableViewRowAnimationAutomatic];
[tableView endUpdates];
[CATransaction commit];
I am sure that you can easily achieve this by using a custom table view class instead of using dependencies from external frame work just inherit from the uitable view and add subviews to it.
But if you insist to keep it this way. take a reference in your own variable before deleting it.
Swift (the idea is the same, you can of course use this in obj-c):
UIView.animateWithDuration(0.3, animations: { () -> Void in
self.tableView.scrollToRowAtIndexPath(indexPathes, withRowAnimation: UITableViewRowAnimation.None)
}, completion: { (Bool) -> Void in
// The logic you want to execute after the animation
})