putting limitation for checkbox in UITableView Objective-C - objective-c

Question

I create table programmatically with different sections and rows, i create check box inside table with pictures as a box
I want to put limitation for this check box
would you please help me
Edit :
my question is how can I choosing just one check box- limitation of choice
and also how can I unselect a box and remove the checkmark
here is code for check box row
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *key = [[self sectionKeys] objectAtIndex:[indexPath section]];
NSArray *contents = [[self sectionContents] objectForKey:key];
NSString *contentForThisRow = [contents objectAtIndex:[indexPath row]];
if (indexPath.section != 2) {
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"Cell"];
cell.textLabel.text =contentForThisRow;
return cell;
}
else {
CheckBoxAbsenceTableViewCell *cell = (CheckBoxAbsenceTableViewCell*)[tableView dequeueReusableCellWithIdentifier:#"CheckBoxAbsenceTableViewCell"];
cell.imageView.image=[UIImage imageNamed:#"emptycheck-box.png"];
cell.checkBox.image = image;
if(indexPath.row == 0){
cell.absenceCode.text =#"Red";
}
else if (indexPath.row == 1){
cell.absenceCode.text =#"Green";
}else if(indexPath.row == 2){
cell.absenceCode.text =#"Blue";
}
return cell;
}
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
CheckBoxAbsenceTableViewCell *selectedCell = [tableView cellForRowAtIndexPath:indexPath];
selectedCell.checkBox.image =[UIImage imageNamed:#"checkmark.png"];
}
Thanks in advance!

Answer 1

The easy solution is to add a UIInteger _selectedIndex instance var to your view controller.
In viewDidLoad set it to -1 (non of the rows is selected)
Then when user select a cell, save the selected index and reload the tableView:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
_selectedIndex = indexPath.row;
[self.tableView reloadData];
}
Change the cellForRowAtIndexPath method so it will select only the selected cell:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *key = [[self sectionKeys] objectAtIndex:[indexPath section]];
NSArray *contents = [[self sectionContents] objectForKey:key];
NSString *contentForThisRow = [contents objectAtIndex:[indexPath row]];
if (indexPath.section != 2) {
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"Cell"];
cell.textLabel.text =contentForThisRow;
return cell;
}
else {
CheckBoxAbsenceTableViewCell *cell = (CheckBoxAbsenceTableViewCell*)[tableView dequeueReusableCellWithIdentifier:#"CheckBoxAbsenceTableViewCell"];
if (indexPath.row == _selectedIndex) {
cell.checkBox.image =[UIImage imageNamed:#"checkmark.png"];
}
else {
cell.checkBox.image = [UIImage imageNamed:#"emptycheck-box.png"];;
}
if(indexPath.row == 0){
cell.absenceCode.text =#"Red";
}
else if (indexPath.row == 1){
cell.absenceCode.text =#"Green";
}else if(indexPath.row == 2){
cell.absenceCode.text =#"Blue";
}
return cell;
}
}

Answer 2

From a UI design perspective, you should be using the cell.accessoryType and the UITableViewCellAccessoryCheckmark accessory.
You need to keep track of the selected (i.e. checked) indexPath in your data model. Lets call this self.idxPathSelected.
This didSelectRowAtIndexPath will add checkmark to the selected row, and clear checkmark from the previously selected row:
- (void) tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[tableView deselectRowAtIndexPath:indexPath animated:NO];
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
cell.accessoryType = UITableViewCellAccessoryCheckmark;
if (self.idxPathSelected != nil)
{
cell = [tableView cellForRowAtIndexPath:self.idxPathSelected];
cell.accessoryType = UITableViewAccessoryNone;
}
self.idxPathSelected = [NSIndexPath indexPathForRow:indexPath.row inSection:indexPath.section];
}
and in your cellForRowAtIndexPath, something like this:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
...
if ((self.idxPathSelected != nil) && ([self.idxPathSelected compare:indexPath] == NSOrderedSame))
cell.accessoryType = UITableViewCellAccessoryCheckmark;
else
cell.accessoryType = UITableViewCellAccessoryNone;
...
}