Build a tabbar view controller from scratch - iphone

Question

Apple's tab bar controller has a lot of limitations. One important limitation is that you can't modify the tab bar in a rejection safe mode. My tab bar has a simple sliding movements and it's multi row.
For those reasons I decided to build a TBVC from the beginning; everything seems to work correctly, but I'm really messing around with rotation. Every time that I change orientation main view frames are changed.
Here is my hierarchy from top to the container view:
-MainView--contains-->TabBarView+containerView
The containerView is the view used to contain views loaded from the other controllers.
Here is the -loadView method of my CustomTabBaViewController
- (void)loadView
{
UIView *theView=[[UIView alloc]initWithFrame:[[UIScreen mainScreen]bounds]];
theView.autoresizingMask=UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;
theView.backgroundColor=[UIColor greenColor];
containerOfControllersView=[[UIView alloc] initWithFrame:theView.bounds];
containerOfControllersView.backgroundColor=[UIColor blueColor];
containerOfControllersView.autoresizingMask=UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;
[theView addSubview:containerOfControllersView];
ideoloTabBar=[[IdeoloTabBar alloc]initWithNumberOfControllers:[controllers count]];
[theView addSubview:ideoloTabBar];
self.view=theView;
[theView release];
}
When I set a new view from another controller I use this method:
-(void)setCurrentViewWithView:(UIView*)theView{
if ([[self.containerOfControllersView subviews] count]>0) {
UIView *tagView=[self.containerOfControllersView viewWithTag:555];
tagView.tag=0;
[tagView removeFromSuperview];
}
theView.tag=555;
theView.autoresizingMask=UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;
theView.frame=[[UIScreen mainScreen]applicationFrame];
[self.containerOfControllersView addSubview:theView];
[self.view bringSubviewToFront:ideoloTabBar];
}
As you can see the views from other view controllers are applied using the applicationFrame.
When I rotate the device happens something wrong, the mainview not only is resized according to the new orientation but also moved by 20px (status bar size) to the botton, thus leaving a gap between the status bar and the container view. Since I gave the mainview the screen bounds I can't understand with it should be moved.
UPDATE
I'm trying a different approach so I've modified the loadView like that:
- (void)loadView
{
[super loadView];
containerOfControllersView=[[UIView alloc] initWithFrame:self.view.bounds];
containerOfControllersView.backgroundColor=[UIColor blueColor];
containerOfControllersView.autoresizingMask=UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;
self.view.backgroundColor=[UIColor greenColor];
[self.view addSubview:containerOfControllersView];
ideoloTabBar=[[IdeoloTabBar alloc]initWithNumberOfControllers:[controllers count]];
[self.view addSubview:ideoloTabBar];
}
And in the setCurrentViewWithView:(UIView*)theView I've modified the line with
theView.frame=self.view.bounds;
instead of using the applicationFrame.
NOW:
On iPhone when I try to load a modalView it cuts about 40px at the bottom
On iPad when I try to load a modalView it lefts 20px at the bottom, because 20px are under the status bar but wantsFullScreen is NO.
UPDATE 2
It seems that the presentModalViewController should be called from the root view controller. I will create a protocol and an abstract UIViewController subclass to implement it an load it correctly.
Any suggestion? work around?

Answer 1

I don't like the approach of creating an entirely custom TabBarController from scratch. I like to put a custom view on top of a real TabBar as a subview, and then pass all the button presses to the real TabBarController. This way you don't have to code a window manager yourself.
- (void)tabButtonPressed:(id)sender
{
UIButton *button = (UIButton *)sender;
if (button.tag == HomeButton)
self.tabBarController.selectedIndex = 0;
// etc.
}
This should also be rejection safe.

Answer 2

This has been addressed here: Application frame leaves blank line at the top
But, you could also specify your frame by subtracting 20 from y:
CGRect rect = [[UIScreen mainScreen] applicationFrame];
theView.frame = CGRectMake(rect.origin.x, rect.origin.y - 20, rect.size.width, rect.size.height);

Answer 3

It has been a while since I'm using my custom TabBarViewController with disappearing tabbar and it seems to work properly both on iPad and iPhone.
The main problem that I had was due to an incorrect assignment to the content view frame and probably to a wrong assumption that modalVC were loaded from the current view controller.
First point: the content view should use the bounds of the main view, here is a part of the loadView method of the Root View Controller:
[super loadView];
containerOfControllersView=[[UIView alloc] initWithFrame:self.view.bounds];
Second:before add as a subview a view of a view controller remark to it that its frame should have the same bounds of its new parent view.
theView.frame =self.view.bounds;
Third: modal view controllers should be loaded from the root view controller or the will never have correct size. That's why I've implemented a base abstract class for each view controllers that inherit a protocol that manage the presetation and dismissing of modal viewcontrollers.
Hope this helps someone else.
Andrea