How to rearrange UITableView with custom cells? - ios

I have a table view with custom cells. The cells are filled with my data.
Now I want to enable the user to rearrange the rows. I have implemented the methods, but while dragging to reorder the cell, I can see it shows like it is trying to do but cannot move anywhere. It moves like 10 pixel as if it will do the rearrange but goes back to its position. How to reorder the rows with custom cell?
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete)
{
[self.dataSource removeObjectAtIndex:indexPath.row];
[tableView reloadData];
}
}
-(UITableViewCellEditingStyle)tableView:(UITableView*)tableView editingStyleForRowAtIndexPath:(NSIndexPath*)indexPath
{
if (self.mytableView.editing)
{
return UITableViewCellEditingStyleDelete;
}
return UITableViewCellEditingStyleNone;
}
-(BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
return YES;
}
-(BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath
{
return YES;
}
-(void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath *)destinationIndexPath
{
id stringToMove = [self.dataSource objectAtIndex:sourceIndexPath.row];
[self.dataSource removeObjectAtIndex:sourceIndexPath.row];
[self.dataSource insertObject:stringToMove atIndex:destinationIndexPath.row];
}
-(NSIndexPath *)tableView:(UITableView *)tableView targetIndexPathForMoveFromRowAtIndexPath:(NSIndexPath *)sourceIndexPath toProposedIndexPath:(NSIndexPath *)proposedDestinationIndexPath
{
if (proposedDestinationIndexPath.section != sourceIndexPath.section)
{
return sourceIndexPath;
}
return proposedDestinationIndexPath;
}

I know this is old but I will still answer it. The issue here is with your tableView: targetIndexPathForMoveFromRowAtIndexPath: toProposedIndexPath: method (your last method)
Your logic is preventing any moving from happening. Your if-statement:
if (proposedDestinationIndexPath.section != sourceIndexPath.section)
is saying if the desired location (the location the user wants to bring the cell) is not my current location, then return my current location (so do not move the cell). Otherwise, if my desired location (the new location I want to go) is my current location then return the desired location (which is actually my current location).
I hope that makes sense, so basically you are saying that no matter what, make sure every cell always remains in its current location. To fix this, either remove this method (this is not needed unless there are moves that are illegal) or switch your two return statements, so:
-(NSIndexPath *)tableView:(UITableView *)tableView
targetIndexPathForMoveFromRowAtIndexPath:(NSIndexPath *)sourceIndexPath
toProposedIndexPath:(NSIndexPath *)proposedDestinationIndexPath {
if (proposedDestinationIndexPath.section != sourceIndexPath.section) {
return proposedDestinationIndexPath;
}
return sourceIndexPath;
}
In fact, the only method required to allow re-arranging is: tableView: moveRowAtIndexPath: toIndexPath:. So again, unless you want specific behavior out of the other methods you can save some code and just remove most of them (especially since in this situation you are mainly just implementing the defaults).

Related

Custom moving tableview cell: How to always keep first cell at top of UITableView when "moveRowAtIndexPath"

I need to keep my first cell always located at top of tableview when i move others cell.I spent a lot of time and many ways button i haven't figure out that how to solve this problem.
This is my code:
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
//...do something to custom first cell design from xib file
//...do some thing to custom normal cells(cells at below of first cell)
[firstcell setEditing:NO animated:YES];
firstcell.userInteractionEnabled=NO;
if (indexPath.row==0)
{
return firstcell;
}
else
{
return cell;
}
}
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath
{
if (indexPath.row == 0) // Don't move the first row
return NO;
return YES;
}
-(BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
return YES;
}
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath *)destinationIndexPath {
// i just change datasource for tableview at here
}
And there is my tableview when I move cell (normal cell).
I wanna keep first cell (blue cell) always be at top and not be interact by others cell.
You need to implement one more delegate method:
- (NSIndexPath *)tableView:(UITableView *)tableView targetIndexPathForMoveFromRowAtIndexPath:(NSIndexPath *)sourceIndexPath toProposedIndexPath:(NSIndexPath *)proposedDestinationIndexPath {
if (proposedDestinationIndexPath.row == 0) {
// Don't allow a row to be moved to the first row position
return [NSIndexPath indexPathForRow:1 inSection:0];
} else {
return proposedDestinationIndexPath;
}
}
This code assume you only have one section in your table view.
The point of this method is to tell the table view that if the proposed destination for the row being moved isn't appropriate, the returned value should be used. As written here, any attempt to move a row to the top will result in it being moved just below the top row.

iOS UITableView Swipe Left Buttons don't appear

I'm trying to implement the swipe left to display the delete button.
The cell moves left, but there are no visible buttons. Why does this happen? What is the solution?
To be clear, I have searched on StackOverflow and tried at least a dozen posted "solutions", but none of them have worked for me.
Thanks in advance.
I tried using the following code, which does seem to make the table cell move, but the log does not show NSLog(#"commitEditingStyle");. Why does this happen?
// Swipe to delete.
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
NSLog(#"commitEditingStyle");
if (editingStyle == UITableViewCellEditingStyleDelete) {
NSLog(#"UITableViewCellEditingStyleDelete");
[listData removeObjectAtIndex:indexPath.row];
[self.tableView deleteRowsAtIndexPaths:#[indexPath] withRowAnimation:UITableViewRowAnimationFade];
[self.tableView reloadData];
}
}
And I have tried adding:
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
return YES;
}
Here is a screenshot:
The problem was that the table size was larger than my screen size. The solution is to set the constraints to match the width of the view.
// During startup (-viewDidLoad or in storyboard) do:
self.tableView.allowsMultipleSelectionDuringEditing = NO;
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath {
// Return YES if you want the specified item to be editable.
return YES;
}
// Override to support editing the table view.
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
if (editingStyle == UITableViewCellEditingStyleDelete) {
//add code here for when you hit delete
}
}

Reordered cells in UITableView to remain in the same order

I prepared a TableView containing data from NSMutableArray. There is an option to edit and reorder rows. All works fine, until the phone is shut down or too many applications are running in the background - there is an error message in Xcode that the application exited unexpectedly due to memory pressure.
I would like to add some command to remain and remember previous cell order so after iPhone shut down user will have the same order as before.
Below is the code I am using for enabling reorder. Is there anything missing? Please bear with me, these are just my initial developing attempts.
Thanks in advance for any help!
Matus
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
return YES;
}
- (UITableViewCellEditingStyle)tableView:(UITableView *)tableView editingStyleForRowAtIndexPath: (NSIndexPath *)indexPath {
return UITableViewCellEditingStyleDelete;
}
- (void)tableView:(UITableView *)tableView commitEditingStyle: (UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete) {
[_Title removeObjectAtIndex:indexPath.row];
[_Images removeObjectAtIndex:indexPath.row];
[tableView deleteRowsAtIndexPaths:#[indexPath] withRowAnimation:UITableViewRowAnimationFade];
}
}
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath
{
NSString *item = [self.Title objectAtIndex:fromIndexPath.row];
[self.Title removeObject:item];
[self.Title insertObject:item atIndex:toIndexPath.row];
NSString *image = [self.Images objectAtIndex:fromIndexPath.row];
[self.Images removeObject:image];
[self.Images insertObject:image atIndex:toIndexPath.row];
}
- (void)tableView:(UITableView *)tableView didEndReorderingRowAtIndexPath:(NSIndexPath *)indexPath
{
[self.tableView reloadSections:[NSIndexSet indexSetWithIndex:indexPath.section]
withRowAnimation:UITableViewRowAnimationNone];
}
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath
{
return YES;
}
I really wish I could comment at this point... So, I already apologize for writing this as an answer.
You really shouldn't discard the fact that your app is being shut down by the OS. This is the main issue. Not the persistence of the data.
After you fix that, you can then look into how to persist your data (using Core Data, or a simple plist file) when leaving the app (using either one of the method in the UIApplicationDelegate protocol, or one of the application notifications). And loading it back when reopening it.
You need to make sure that you're persisting the changes to self.Title and self.Images.
If you add a call to the code you use to save the order of your rows at the end of tableView:MoveRowAtIndexPath:toIndexPath: then any change in the order of the rows should always be saved.
You can test that this is working by stopping the app (either by Cmd+. or the stop sign) immediately after you move a row.

Preventing a specific move in moveRowAtIndexPath

I have a UITableView in my Objective-C iOS app, of which I need to have a specific cell displaying information while all the others cells should move freely.
With my current code, I prevented said cell to be moved by other cells, but it is still possible to move underneath it.
This cell is not part of my Data model so I really need to keep this in the controller layer.
In other words, I'm looking for a way to prevent the default behaviour.
Below is my current code:
-(void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath *)destinationIndexPath
{
if (destinationIndexPath.row == [tableView numberOfRowsInSection:0]-2) {
//prevent the move
}
else {
[[BNRItemStore sharedStore] moveItemAtIndex:sourceIndexPath.row toIndex:destinationIndexPath.row];
}
}
What should I change in order to obtain the desired functionality?
Did you try to implement this delegate method?
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath;
Use targetIndexPathForMoveFromRowAtIndexPath as below,
// Allows customization of the target row for a particular row as it is being moved/reordered
- (NSIndexPath *)tableView:(UITableView *)tableView targetIndexPathForMoveFromRowAtIndexPath:(NSIndexPath *)sourceIndexPath toProposedIndexPath:(NSIndexPath *)proposedDestinationIndexPath {
if( proposedDestinationIndexPath is ok ) {
return proposedDestinationIndexPath;
} else {
return sourceIndexPath;
}
}

Creating Grouped UITableview with Different Cell Types

I need to create a grouped uitableview that includes some sections and possibly different cell types in each sections.
I am trying to create something like old foursquare app, user page (includes 'leaderboard', 'friend suggestions', 'friends', 'stats', 'most explored categories' ... sections).
I am fairly new to ios programming, so that view may not be a grouped uitableview.
What I especially stuck is creating different cells for sections, and finding out which cells are clicked.
My data source will be 2 different NSArray* that consists of different data types, that's why I need different custom cells.
Since you have two different sets of data and you need to display both in different sections, you have to split the data source methods into two.
Basically, choose which dataset you want to be first and off you go.
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
if(section)return secondArray.count;
//Essentially, if statements evaluate TRUE and move forward if the inside is 1 or greater (TRUE == 1)
return firstArray.count;
//If the first if statement return hits, then the code will never reach this statement which turns this into a lighter if else statement
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
if(indexPath.section)
{
//do stuff with second array and choose cell type x
}
else
{
//do stuff with first array and choose cell type y
}
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
//Get the cell with: UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
if(indexPath.section)
{
//perform action for second dataset
}
else
{
//perform action for first dataset
}
}
For headers, you can use either of these methods and just keep the same type of styling as above:
- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section;
- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section;
You can create multiple custom subclasses of UITableViewCell, and in the tableView:cellForRowAtIndexPath: method for your UITableViewDataSource, you can use if-statements to determine what type of cell to use.
For example, here's a rough outline of what I might do:
-(UITableViewCell *)tableView:(UITableView*)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
//First, determine what type of object we're showing
if (indexPath.section == 0) {
//Create and return this cell.
} else if (indexPath.section == 1) {
//Create and return this cell.
}...
}
Here's how you'd implement numberOfRowsInSection:
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
if (section == 0) {
return [firstSectionArray count];
} else if (section == 1) {
return [secondSectionArray count];
} ...
}
For didSelectRowAtIndexPath
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.section == 0) {
ObjectSelected *objectSelected = [firstArray objectAtIndex:indexPath.row];
//Now you've got the object, so push a view controller:
DetailViewController *dvc = [[DetailViewController alloc] init];
dvc.objectSelected = objectSelected;
[self.navigationController pushViewController:dvc];
} else if (indexPath.section == 1) {
//Same thing, just call [secondArray objectAtIndex:indexPath.row] instead!
}
}

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