Parent child navigation UIViewController causes exception for editing form - ios

Question

I have a parent->child navigation setup in application. I use navigation via pushViewController function.
-(void)loadMemosViewController:(id)sender{
if(activeHullGuid != nil && activeHullGuid.length > 0)
{
NSString *storyboardName = #"MainStoryboard_iPhone1";
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:storyboardName bundle:nil];
MemosViewController *loginVC = [storyboard instantiateViewControllerWithIdentifier:#"sid_Memos"];
loginVC.keyReference = [[KeyValuePairIS alloc] initWithData:&controllerID:activeHullGuid];
[self.navigationController pushViewController:loginVC animated:YES];
}
}
for back navigation I use only default implementation in IOS (that would be a click on a back button).
This setup works for most situations, but recent implementation is causing problems.
The problem is this:
I have parent view controller named "hullViewController" and a child "memosViewController". The navigation between them works. Child does not report any information back to parent. HullViewController is also an editable form, which changes edit state via button in navigation bar.
Now if I change this edit/read state on hullViewController works nonstop. If I visit the child memosViewController, and go back to parent, I can only change state once more, then application crashes with exc_bad_access code=1.
After profiling with "Zombies" I found the culprit for exception is my probably disposed child memosViewController.
An Objective-C message was sent to a deallocated 'MemosViewController' object (zombie) at address: 0xdd52f10
it seams to crash on an IOS internal event, since none of my breakpoints are hit before crash.
A you can see the child is instanced during creation and I don't reference it to nothing else. Why would the edit state change request the child object?
What I tried already:
-declaring MemosViewController as a class variable. (application did not crash anymore, but would not change state anymore).
-initialising MemosViewController on viewDidLoad, changed nothing.
-calling child with class init only (not via storyboard), loaded child without UI, but result was same.
Project is set up with ARC, so I have minimum control on disposal of objects.
I have been searching for a solution quite a while now, with no results. Any help to solve my error editing if I visit the child would be appreciated.
UPDATE
I have additionally discovered, that when I get back to parent from child, the reference self.navigationItem still points to child, and any update to navigation buttons crashes the app.
**attaching custom ViewController, since it could be related to problem **
#import "UITableViewControllerEx.h"
#import "UITextFieldEx.h"
#import "UITextViewEx.h"
#import "GlobalValues.h"
#import "UITableViewEx.h"
#interface UITableViewControllerEx ()
#end
#implementation UITableViewControllerEx
UIBarButtonItem *bbi_navigateToMaster;
UIBarButtonItem *editButton;
UIButton *cmdEdit;
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Uncomment the following line to preserve selection between presentations.
// self.clearsSelectionOnViewWillAppear = NO;
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem;
[self setNavigationBackground];
[self setApplicationTintColor];
[self setApplicationTitleFont];
[self setupLeftBarButtonItem];
[self setBackButton];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
//UITextFieldEx delegate to control the length of fields
- (BOOL)textField:(UITextFieldEx *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
NSUInteger newLength = [textField.text length] + [string length] - range.length;
return (newLength > textField.maxLength) ? NO : YES;
}
//UITextViewEx delegate to control the length of fields
-(BOOL)textView:(UITextViewEx *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text{
NSUInteger newLength = [textView.text length] + [text length] - range.length;
return (newLength > textView.maxLength) ? NO : YES;
}
//function to set left button to always pop to root controller
- (void)setBackButtonToReturnToMaster {
UIButton *cmdHome = [[UIButton alloc] initWithFrame:CGRectMake(0,0,30,30)];
[cmdHome setImage:[UIImage imageNamed:#"home"] forState:UIControlStateNormal];
bbi_navigateToMaster = [[UIBarButtonItem alloc] initWithCustomView:cmdHome];
[cmdHome addTarget:self action:#selector(backToMaster:) forControlEvents:UIControlEventTouchUpInside ];
self.navigationItem.leftBarButtonItems = [NSArray arrayWithObjects:bbi_navigateToMaster , nil];
/*
bbi_navigateToMaster = [[UIBarButtonItem alloc] initWithTitle:#"" style:UIBarButtonItemStylePlain target:self action:#selector(backToMaster:)];
self.navigationItem.leftBarButtonItems = [NSArray arrayWithObjects:bbi_navigateToMaster , nil];
[bbi_navigateToMaster setImage:[UIImage imageNamed:#"home"]];
[bbi_navigateToMaster setImageInsets:UIEdgeInsetsMake(2, 2, 2, 2)];*/
}
//pop to root controller
-(void)backToMaster:(id)sender {
if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPad) {
}
else { [self.navigationController popToRootViewControllerAnimated:YES]; }
}
//find superview element of given type
- (UIView *)findSuperViewWithClass:(Class)superViewClass uiViewToSearch:(UIView*)bottomView{
UIView *superView = bottomView.superview;
UIView *foundSuperView = nil;
while (nil != superView && nil == foundSuperView) {
if ([superView isKindOfClass:superViewClass]) {
foundSuperView = superView;
break;
} else {
superView = superView.superview;
}
}
return foundSuperView;
}
-(void)setNavigationBackground{
if ([self.navigationController.navigationBar respondsToSelector:#selector(setBackgroundImage:forBarMetrics:)] ) {
UIImage *image = [UIImage imageNamed:#"navigationBackground"];
[self.navigationController.navigationBar setBackgroundImage:image forBarMetrics:UIBarMetricsDefault];
UIView* uv = [[UIView alloc] initWithFrame:CGRectMake(0, self.navigationController.navigationBar.frame.size.height-1,self.navigationController.navigationBar.frame.size.width, 1)];
[uv setBackgroundColor:[GlobalValues getTintColor]];
[self.navigationController.navigationBar insertSubview:uv atIndex:10];
}
}
//sets the tint color of szstem items (title, szstem buttons, ...)
-(void)setApplicationTintColor {
NSArray *ver = [[UIDevice currentDevice].systemVersion componentsSeparatedByString:#"."];
if ([[ver objectAtIndex:0] intValue] >= 7) {
self.navigationController.navigationBar.barTintColor = [GlobalValues getTintColor];
self.navigationController.navigationBar.tintColor = [GlobalValues getTintColor];
self.navigationController.navigationBar.translucent = NO;
[self.navigationController.navigationBar setTitleTextAttributes:#{NSForegroundColorAttributeName : [UIColor whiteColor]}];
UIColor *color = [GlobalValues getTintColor];
self.view.tintColor = color;
}else {
//self.navigationController.navigationBar.tintColor = [GlobalValues getTintColor];
/*NSDictionary *textTitleOptions = [NSDictionary dictionaryWithObjectsAndKeys:[UIColor whiteColor], UITextAttributeTextColor, [UIColor clearColor], UITextAttributeTextShadowColor, nil];
[[UINavigationBar appearance] setTitleTextAttributes:textTitleOptions];*/
}
}
//sets the navigation title
-(void)setApplicationTitleFont {
NSArray *ver = [[UIDevice currentDevice].systemVersion componentsSeparatedByString:#"."];
if ([[ver objectAtIndex:0] intValue] >= 7) {
[self.navigationController.navigationBar setTitleTextAttributes:
[NSDictionary dictionaryWithObjectsAndKeys:
[UIFont fontWithName:#"HelveticaNeue-Light" size:21],
NSFontAttributeName, [UIColor whiteColor], UITextAttributeTextColor, [UIColor clearColor], UITextAttributeTextShadowColor, nil]];
}else {
[self.navigationController.navigationBar setTitleTextAttributes: #{
UITextAttributeTextColor: [UIColor whiteColor],
UITextAttributeFont: [UIFont fontWithName:#"Helvetica-Light" size:21.0f]
}];
}
}
-(void)setupLeftBarButtonItem{
cmdEdit = [[UIButton alloc] initWithFrame:CGRectMake(0,0,30,30)];
[cmdEdit setImage:[UIImage imageNamed:#"locked"] forState:UIControlStateNormal];
editButton = [[UIBarButtonItem alloc] initWithCustomView:cmdEdit];
[cmdEdit addTarget:self action:#selector(setEditState) forControlEvents:UIControlEventTouchUpInside];
}
- (UIBarButtonItem *)leftBarButtonItem
{
if (self.tableView.editing) {
[cmdEdit setImage:[UIImage imageNamed:#"unlocked"] forState:UIControlStateNormal];
return editButton;
}
else {
[cmdEdit setImage:[UIImage imageNamed:#"locked"] forState:UIControlStateNormal];
return editButton;
}
}
-(void)updateEditButton{
if (self.tableView.editing) {
[cmdEdit setImage:[UIImage imageNamed:#"unlocked"] forState:UIControlStateNormal];
}
else {
[cmdEdit setImage:[UIImage imageNamed:#"locked"] forState:UIControlStateNormal];
}
}
-(void)setEditState{
if (!self.tableView.editing) {
[self setEditing:YES animated:YES];
} else {
[self setEditing:NO animated:YES];
}
[self updateEditButton];
}
}*/
-(void) setBackButton{
UIButton *backBtn = [UIButton buttonWithType:UIButtonTypeCustom];
UIImage *backBtnImage = [UIImage imageNamed:#"back"] ;
[backBtn setBackgroundImage:backBtnImage forState:UIControlStateNormal];
[backBtn addTarget:self action:#selector(goback) forControlEvents:UIControlEventTouchUpInside];
backBtn.frame = CGRectMake(0, 0, 30, 30);
UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithCustomView:backBtn] ;
self.navigationItem.leftBarButtonItem = backButton;
}
- (void)goback
{
[self.navigationController popViewControllerAnimated:YES];
}
#pragma mark - Table view data source
#pragma mark - Table view delegate
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 0;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return 0;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
}
- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath
{
cell.backgroundView=[[UIView alloc] initWithFrame:CGRectZero];
cell.backgroundColor = [UIColor clearColor];
cell.layer.backgroundColor = [UIColor clearColor].CGColor;
}
-(UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section {
UIView *customTitleView = [ [UIView alloc] initWithFrame:CGRectMake(10, 0, 300, 44)];
UIView *customTitleLineView = [ [UIView alloc] initWithFrame:CGRectMake(10, 43, self.view.frame.size.width -20, 0.5f)];
customTitleLineView.backgroundColor = [GlobalValues getTintColor];
UILabel *titleLabel = [ [UILabel alloc] initWithFrame:CGRectMake(20, 0, 300, 44)];
titleLabel.text = [self tableView:tableView titleForHeaderInSection:section];
titleLabel.font = [UIFont fontWithName:#"HelveticaNeue" size:18];
titleLabel.textColor = [GlobalValues getTintColor];
titleLabel.backgroundColor = [UIColor clearColor];
if (titleLabel.text.length != 0) {
[customTitleView addSubview:customTitleLineView];
}
[customTitleView addSubview:titleLabel];
return customTitleView;
}
#end

Answer 1

Seems I have found a solution to my problem.
Class UITableViewControllerEx contains functionality to setup edit button. The class variable "UIBarButtonItem *editButton;" is then used as edit button on all forms that inherit from "UITableViewControllerEx"
the solution was to instantiate UIBarButtonItem on each form inheriting UITableViewControllerEx with local name (like editButtonHull) and given as param to logic of superclass.
Thanks to #akashg for suggestion that Navigation bar modification might be the problem