Add editing elements to UITableViewCell - objective-c

I have a couple of rows in a table view which I like to edit.
I thought that setEditing method would give me a Edit and Delete button, but it only shows a Delete button. Because I don't have a detail view controller that's going to be pushed in didSelectRowAtIndexPath I thought I could show a couple of editing elements in the selected cell.
I need to add three buttons to specify priority on assignments: Low, High and Medium priority. This means that I have to change the height of the selected cell to make room for these buttons, I think that's rather easy to do.
What I'm wondering is if this is the correct path to choose?
I have done quite a lot research today without finding examples of how other have solved editing in a UITableViewCell. If you edit a contact in the Contacts app in the iPhone the UITableViewCells changes to enable quick and easy editing, that's what I'm looking for.
So what do you have for tips for me regarding this question?
Edit #1
My code in didSelectRowAtIndexPath is:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
Cell *selectedCell = (Cell *)[tableView cellForRowAtIndexPath: indexPath];
UIButton *btn = [UIButton buttonWithType: UIButtonTypeRoundedRect];
btn.frame = CGRectMake(0, 0, 50, 100);
btn.titleLabel.text = #"Set this item to High Priority";
btn.backgroundColor = [UIColor greenColor];
[selectedCell.contentView addSubview: btn];
self.editing = YES;
[tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject: indexPath] withRowAnimation:UITableViewRowAnimationFade];
}
Code for heightForRowAtIndexPath:
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
Cell *cell = nil;
if (self.editing)
cell = (Cell *)[tableView cellForRowAtIndexPath: indexPath];
else
cell = nil;
BOOL expandCell = NO;
NSInteger expandationHeight = 0;
if (cell != nil)
{
for (UIButton *btn in cell.contentView.subviews)
{
NSLog(#"A button was found.");
expandationHeight = 70;
expandCell = YES;
}
}
return expandationHeight + heightOfOtherElements;
}
When I click at a cell nothing happends but everything becomes disabled, I can't click any elements on the hole view. This has something to do with [tableView cellForRowAtIndexPath: indexPath], because if I uncomment that line the UI does not become disabled.
What am I doing wrong?

That's not too complicated though it requires some stuff.
You want to change the content of one cell or of all cells?
To specify a specific height for one cell, use the - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath delegate method.
It is called for each cell each time the table view is displayed. If you want to change a single row, call reloadRowsAtIndexPaths:withRowAnimation: method from UITableView. If you want to update all cells, simply use - (void)reloadData method.
You can also access a specific cell using - (UITableViewCell *)cellForRowAtIndexPath:(NSIndexPath *)indexPath method from UITableView. Then you can reconfigure it to add various elements on it, as you want.
Thus, when a cell is selected, check whether you have to edit it or not, then :
update your cell get from cellForRowAtIndexPath
be sure your method tableView:heightForRowAtIndexPath: will return the good height
tell the table view to update the view using reloadRowsAtIndexPaths:withRowAnimation:

Related

Updating subviews in cells on a UITableView

I'm developing an application in iPad 6.0 using Storyboards.
Let me first explain my goal. I'm trying to achieve a Master-Detail (SplitViewController-like) View Controller using 2 UITableViewControllers.
The first UITableView("Master"), let's call this HeaderTableView, as the name implies, lists down the Headers for the...
...Second UITableView("Detail"), let's call this the EncodingTableView, which contains a programmatically changing CustomTableViewCell (subviews contained within each cell may be a UITextField, UIButton or UISwitch).
See EncodingTableView.m
- (void)updateEncodingFields:(NSArray *)uiViewList
{
// Add logic for determining the kind of UIView to display in self.tableView
// Finally, notify that a change in data has been made (not working)
[self.tableView reloadData];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *encodingFieldsTableId = #"encodingFieldsTableId";
CustomTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:encodingFieldsTableId];
if (cell == nil) {
cell = [[CustomTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:encodingFieldsTableId];
}
// Change text in textView property of CustomTableViewCell
cell.encodingFieldTitle.text = uiViewList.title;
// added methods for determining what are to be added to [cell.contentView addSubView:]
// data used here is from the array in updateEncodingFields:
}
My HeaderTableView.m, contains the didSelectRowAtIndexPath to update the EncodingTableView
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
if (![selectedIndexPath isEqual:indexPath]) {
selectedIndexPath = indexPath;
[self updateDataFieldTableViewForIndexPath:indexPath];
}
}
- (void)updateDataFieldTableViewForIndexPath:(NSIndexPath *)indexPath {
[self.encodingTableView updateEncodingFields:self.uiViewList];
}
Question
- Data is all ok but why doesn't EncodingTableView "redraw"ing the fields? My
suspicion is that reusing cells has something to do with this but I just can't figure out why.
Screenshots on the result:
Initial Selection in HeaderTableView
Second Selection in HeaderTableView
What I've tried :
I kept seeing suggestions such as [UITableView setNeedsDisplay],
[UITableView reloadData] and [UITableView setNeedsLayout] but none of
them worked.
Removing the reuse of tableViewCells works fine but this causes parts of my
CustomTableView.encodingFieldTitle to disappear. Not to mention that this might cause performance issues if I were to drop reusing cells.
Restrictions:
I know that a good idea is to use a SplitViewController but this is just a subpart of my app (hence not the RootViewController).
Finally, thanks for reading such a long post. ;)
It looks like you are most likely adding subviews inside tableView:cellForRowAtIndexPath:.
The issue is that if you use cell reuse then are not always starting from a blank slate inside tableView:cellForRowAtIndexPath: instead you can possibly be given a cell back that has already been configured once. This is what you are seeing, a cell that has previously had labels added to it is handed back to you and then you add some more labels over the top.
There are a few way to deal with this:
(My preferred option) Create a subview of UITableViewCell with these extra sub views available as properties.
Ensure the cell setup is only done once
A great place to do this is when you actually create a cell when one does not already exist e.g. inside the if (cell) check
if (cell == nil) {
cell = [[CustomTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:encodingFieldsTableId];
// add subview's here and give them some way to be referenced later
// one way of doing it is with the tag property (YUK)
UILabel *subView = [[UILabel alloc] initWithframe:someFrame];
subView.tag = 1;
[cell.contentView addSubview:subView];
}
UILabel *label = (id)[cell.contentView viewWithTag:1];
label.text = #"some value";
One problem i can see in your code is that the cell identifiers used are different in tableView cellForRowAtIndxPath function.
While dequeueing you are using this identifier - > "encodingFieldsTableId"
&
while creating a cell you are using this identifier - > "dataFieldUiGroupTableId".
Ideally these two identifiers should be same !!!
Try adding,
cell.encodingFieldTitle.text = nil;
Before if(cell == nil)
So that whenever your cellForRowAtIndexPath method is called, the string already present in the cell you are going to reuse will get deleted and the new text in uiViewList.title will be displayed.

UITableViewCell with Checkmark not visible

I've a problem with my UITableView inside PopoverController.
When I touch cell, the didSelectRowAtIndexPath function is called, and the cell accessoryType is changed. Example simplified :
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [self.listItems objectAtIndex:indexPath.row];
cell.accessoryType = UITableViewCellAccessoryCheckmark;
[self.tableView reloadData];
[self.popoverController dismissPopoverAnimated:YES];
}
It's working, the cell are checked, but it's not visible on my tableview : I can't see the blue checkmark. However, in touch state on the cell, the checkmark is visible in white (and the cell background is gray). But not visible in default state.
Do you have any idea why my checkmark are not visible in default state ?
Thanks,
Edit: Add screenshot, for a cell with accessoryType = UITableViewCellAccessoryCheckmark
This happened to me when I changed the global tint color to white. Once I realized, I went into the UITableView and change the tint color locally for just this table. Fixed.
I've tried the answer Jacky Boy - didn't help. But something was there in the deselection...
So I've tried to deselect the cell in the didSelectRowAtIndexPath: before adding the checkmark accessory:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
[tableView deselectRowAtIndexPath:indexPath animated:YES];
UITableViewCell* selectedCell = [tableView cellForRowAtIndexPath:indexPath];
if (row != _selectedRow) {
if (selectedCell.accessoryType == UITableViewCellAccessoryNone) {
selectedCell.accessoryType = UITableViewCellAccessoryCheckmark;
_selectedRow = row;
} else if (selectedCell.accessoryType == UITableViewCellAccessoryCheckmark) {
selectedCell.accessoryType = UITableViewCellAccessoryNone;
}
[tableView reloadData];
}
}
And for me it worked at last - the nice dark checkmark now is clearly visible on the cell!
Of course there is a part in cellForRowAtIndexPath: similar to described in arexx's answer.
I had a similar problem where, after reloading the row with a checkmark set as the accessory, the checkmark wouldn't be visible (but would be visible in white when the row was selected). In testing around the problem I discovered that the checkmark is always present in the cell, it's just white-on-white.
My understanding of the problem is that when I ask for the cell to be reloaded (so that I can show it with a checkmark), the existing cell is put on the reuse queue, but is at that time in a selected state (because the user just selected it). It's still in a selected state when the cell comes back off the reuse queue and you re-configure it in tableView:cellForRowAtIndexPath, and because it's selected, the accessory is set in white instead of in a visible colour.
To fix this, I added a line in tableView:cellForRowAtIndexPath to force the cell not to be selected. The accessory is now always visible when the new cell is displayed.
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
// Get a reusable cell - this only works with Storyboard prototype cells
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"MyCell"];
// THE MAGIC BIT
// Force the cell to not be in a selected state.
cell.selected = NO;
// END MAGIC BIT
if (indexPathIsPathOfSelectedRow) {
// This is the selected cell, so show the checkmark accessory.
cell.accessoryType = UITableViewCellAccessoryCheckmark;
} else {
// In case we're reusing a cell that previously showed a checkmark, clear it.
cell.accessoryType = UITableViewCellAccessoryNone;
}
return cell;
}
Mine was the most stupidest reason. I had created a tableview in storyboard, with a View Controller of size 5.5 inch and forgot to apply the layout constraints.
Then I launched in a 4 inch phone, Everything looked fine except the accessory view was not visible because of tableviews width was greater than that of the phone screen. It took me 3 hours to find out my mistake.
You are reloading the UITableView so in theory the cells are recreated and this time without the checkmark. Do the following:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [self.listItems objectAtIndex:indexPath.row];
cell.accessoryType = UITableViewCellAccessoryCheckmark;
[self.popoverController dismissPopoverAnimated:YES];
}
Running under iOS 6.1, the behavior I see is a cell with a white check mark on an almost white background. This appears to be happening because the code that draws the check mark accessory believes the cell is in a highlighted state, so rather than drawing the check mark in the normal blue color, it is drawn in white.
Setting the selected state of the cell did not work for me but setting the highlighted state immediately before setting the accessory type did. With the following in place, I always get a dark blue check mark.
cell.highlighted = NO;
if (checked)
self.accessoryType = UITableViewCellAccessoryCheckmark;
else
self.accessoryType = UITableViewCellAccessoryNone;
If you want to reload Data then you should store selected Id in some variable for single selection like rowIndex and then in
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
//check index
if (rowIndex==indexPath.row)
{cell.accessoryType = UITableViewCellAccessoryCheckmark;
}
else{
cell.accessoryType = UITableViewCellAccessoryNone;
}
}
Thanks.
-(UIImageView *)checkmarkImg{
UIImage *image = [[UIImage imageNamed:#"ic_check_black_24dp.png"] changeColor:CLR_BUY];
UIImageView *checkmark = [[UIImageView alloc] initWithImage:image];
return checkmark;
}
cell.accessoryView = [self checkmarkImg];

Cell selection issue with EasyTableView

I have what must be a simple problem with EasyTableView (https://github.com/alekseyn/EasyTableView)
I have a number of horizontally scrolling tables that function properly.
I am able to select a cell and perform a segue, however, once the new view controller is dismissed, I am no longer able to select that cell and perform the same action until I have selected another cell in the same table.
My question is: How can I deselect previously selected the cell programmatically to renable this particular action.
Thanks in advance!
The selectedIndexPath is intentionally persistent in case a user scrolls the selected tableview cell offscreen and then back again. If you don't want this persistence please add the line shown below, after the delegate method (in EasyTableView.m):
- (void)setSelectedIndexPath:(NSIndexPath *)indexPath {
if (![_selectedIndexPath isEqual:indexPath]) {
NSIndexPath *oldIndexPath = [_selectedIndexPath copy];
_selectedIndexPath = indexPath;
UITableViewCell *deselectedCell = (UITableViewCell *)[self.tableView cellForRowAtIndexPath:oldIndexPath];
UITableViewCell *selectedCell = (UITableViewCell *)[self.tableView cellForRowAtIndexPath:_selectedIndexPath];
if ([delegate respondsToSelector:#selector(easyTableView:selectedView:atIndexPath:deselectedView:)]) {
UIView *selectedView = [selectedCell viewWithTag:CELL_CONTENT_TAG];
UIView *deselectedView = [deselectedCell viewWithTag:CELL_CONTENT_TAG];
[delegate easyTableView:self
selectedView:selectedView
atIndexPath:_selectedIndexPath
deselectedView:deselectedView];
// Add this line here!
_selectedIndexPath = nil;
}
}
}

UITableView Center Cell Details

I am trying to sync a UITableView with a UILabel to make sure they show the same data; of course, things will be different in the end, but for testing this is what I need to do.
See the arrow? I want that middle cell (from px44-88) to show the cell.textLabel.text in a UILabel when it is the "middle cell".
I tried using - (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath but I was having so many problems I figured I'd come here to ask if anyone has a better way of doing this. I'm not sure if it would make a difference or not but I am using NSFetchedResultsController to populate my UITableView.
UITableView is a subclass of UIScrollView, so probably you can use UIScrollViewDelegate
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
member to detect which cell is currently in the middle.
I.e. assuming you have a plain table with no sections, and tableView is an outlet for the table, label is an outlet for the label, than this will function in your controller will work:
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
int row = (scrollView.contentOffset.y + tableView.frame.size.height / 2) / 44;
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:row inSection:0];
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
label.text = cell.textLabel.text;
}
Of course, you need to do some scrolling to make it work ;)
You can use visibleCells method to get layout of visible cells for non-plain table and use it to detect cell in the middle of the table.

UITableViewCell unselectable while its accessoryView is selectable

I want to have a UITableViewCell that is not selectable while its accessory view (a UISwitch in my case) is editable.
The issue is that I have two other cells of which one needs to remain active; this is very similar to the following image of the Time/Date selector from the iOS calendar app:
http://www.theiphoneblog.com/images/stories/2009/01/photo.jpg
I cannot post the image due to being a new user.
Note that in this view the "All-day" cell cannot be selected but its UISwitch can be changed, while one of "Starts" and "Ends" cells must remain selected.
I've tried both:
[cell setUserInteractionEnabled:NO];
[cell.contentView setUserInteractionEnabled:NO];
The first one works but does not allow the switch to be changed whereas the second does not work, it allows one of the top cells to be deselected which I do not want to happen.
Implement in delegate method
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
if ([selectablePaths contains:indexPath])
{
// cell selected
selectedPath = indexPath;
}else
{
[tableView deselectRowAtIndexPath:indexPath animated:NO];
[tableView selectRowAtIndexPath:selectedPath animated:YES scrollPosition:UITableViewScrollPositionNone];
}
}
And enable user interaction for all cells.