app crashes when a button is clicked --- in SWIFT - ios

Question

Good Morning
I've a table view with multipel selection enabled of maximum 5 cells .. above it there is a list of 5 buttons and images .. when the user clicked on a cell a photo shall appear in the first empty imageViewabove the table, and when the user clicks on that photo it should disaapear and the cell color return to clear or white color in my case.
my problem is, when i click on a photo which cell is not shown because of scrolling, the app crashes. can you please help me .. how can i check if the indexpath is shown or not because the problem happened when it is not
here is my code :
#IBAction func btnClicked (sender : UIButton)
{
let tester = sender
if (tester == btn1 && img1.image != nil)
{
img1.image = nil
let cell1 = myTable.cellForRowAtIndexPath(img1IP)! as CustomCell
selectedIndexPaths.removeObject(img1IP)
configure(cell1, forRowAtIndexPath: img1IP)
counter--
}
else if (tester == btn2 && img2.image != nil)
{
img2.image = nil
let cell2 = myTable.cellForRowAtIndexPath(img2IP)! as CustomCell
selectedIndexPaths.removeObject(img2IP)
configure(cell2, forRowAtIndexPath: img2IP)
counter--
}
else if (tester == btn3 && img3.image != nil)
{
img3.image = nil
let cell3 = myTable.cellForRowAtIndexPath(img3IP)! as CustomCell
selectedIndexPaths.removeObject(img3IP)
configure(cell3, forRowAtIndexPath: img3IP)
counter--
}
else if (tester == btn4 && img4.image != nil)
{
img4.image = nil
let cell4 = myTable.cellForRowAtIndexPath(img4IP)! as CustomCell
selectedIndexPaths.removeObject(img4IP)
configure(cell4, forRowAtIndexPath: img4IP)
counter--
}
else if (tester == btn5 && img5.image != nil)
{
img5.image = nil
let cell5 = myTable.cellForRowAtIndexPath(img5IP)! as CustomCell
selectedIndexPaths.removeObject(img5IP)
configure(cell5, forRowAtIndexPath: img5IP)
counter--
}
else
{
println("its already empty")
}
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("intrest", forIndexPath: indexPath) as CustomCell
cell.selectionStyle = .None
cell.backgroundColor = UIColor.clearColor()
configure(cell, forRowAtIndexPath: indexPath)
return cell
}
func configure(cell: CustomCell, forRowAtIndexPath indexPath: NSIndexPath) {
cell.lblInCell.text = InterstArr[indexPath.row]
if selectedIndexPaths.containsObject(indexPath) {
// selected
cell.imgInCell.backgroundColor = UIColor.redColor()
}
else if (selectedIndexPaths.containsObject(indexPath) == false ) {
// not selected
cell.imgInCell.backgroundColor = UIColor.whiteColor()
cell.lblInCell.backgroundColor = UIColor.whiteColor()
}
}
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
if selectedIndexPaths.containsObject(indexPath) {
// deselect
println("remove object")
selectedIndexPaths.removeObject(indexPath)
////////////
if (img1str == InterstArr[indexPath.row])
{
img1.image = nil
println("remove 1 object")
}
else if ( img2str == InterstArr[indexPath.row])
{
img2.image = nil
println("remove 2 object")
}
else if (img3str == InterstArr[indexPath.row])
{
img3.image = nil
println("remove 3 object")
}
else if (img4str == InterstArr[indexPath.row])
{
img4.image = nil
println("remove 4 object")
}
else if ( img5str == InterstArr[indexPath.row])
{
img5.image = nil
println("remove 5 object")
}
counter--
// println(counter)
}
else if !(selectedIndexPaths.containsObject(indexPath)) {
// select
if (counter <= 4){
if (img1.image == nil)
{
img1str = InterstArr[indexPath.row]
img1.image = UIImage(named: InterstArr[indexPath.row])
img1IP = indexPath
println("add 1 object")
}
else if (img2.image == nil)
{
img2str = InterstArr[indexPath.row]
img2IP = indexPath
img2.image = UIImage(named: InterstArr[indexPath.row])
println("add 2 object")
}
else if (img3.image == nil)
{
img3str = InterstArr[indexPath.row]
img3IP = indexPath
img3.image = UIImage(named: InterstArr[indexPath.row])
println("add 3 object")
}
else if (img4.image == nil)
{
img4str = InterstArr[indexPath.row]
img4IP = indexPath
img4.image = UIImage(named: InterstArr[indexPath.row])
println("add 4 object")
}
else if (img5.image == nil)
{
img5str = InterstArr[indexPath.row]
img5IP = indexPath
img5.image = UIImage(named: InterstArr[indexPath.row])
println("add 5 object")
}
selectedIndexPaths.addObject(indexPath)
counter++
}
else if (counter > 4)
{
println("you selected 5 already")
}
}
let cell = tableView.cellForRowAtIndexPath(indexPath)! as CustomCell
configure(cell, forRowAtIndexPath: indexPath)
}

Answer 1

Ok then .. the problem was how to check if the indexPath is shown, so here is my answer for those who have the same problem, as an example i posted only one part of the function and you can repeat if (tester == btn1 && img1.image != nil) for the other buttons .. the line to check if the indexPath is visible is this one if ((myTable.cellForRowAtIndexPath(img1IP)) != nil) :
#IBAction func btn1Clicked (sender : UIButton)
{
let tester = sender
if (tester == btn1 && img1.image != nil)
{
if ((myTable.cellForRowAtIndexPath(img1IP)) != nil)
{
println("1 exist")
let cell:CustomCell = myTable.cellForRowAtIndexPath(img1IP) as CustomCell!
cell.imgInCell.backgroundColor = UIColor.whiteColor()
img1.image = nil
selectedIndexPaths.removeObject(img1IP)
}
else
{
img1.image = nil
selectedIndexPaths.removeObject(img1IP)
}
}