Can't seem to find a way to fix a graphic - a light graphic that would remain static as the user navigates from scene to scene. Have been combing forums for a few days, but most answers point to MainWindow.xib, which isn't generated for a storyboard project. Would appreciate any advice.
Here’s what I was able to cobble together thanks to advice from #Max. Like I said, very new to this, so if this code needs tuning please leave a comment so I don’t lead others astray.
Add the image to the app’s main window in the AppDelegate’s didFinishLaunchingWithOptions method :
UIImageView *myGraphic = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"myGraphic.png"]];
[self.window.rootViewController.view addSubview: myGraphic];
[self.window.rootViewController.view sendSubviewToBack: myGraphic];
Then, to make your views transparent so the background shows through - in your viewController class/es, add to viewDidLoad method:
self.view.backgroundColor = [UIColor clearColor];
(And note if you try to decrease the transparency through the alpha property for the view via the Attributes Inspector, it will make everything transparent on that view -buttons, etc - that’s why it needs to be done programmatically.)
Sure, it’s not thoroughly tested. But for now it’s working and it’s a thing of beauty. Thanks all.
You can try to manually add UIImageView to your window and then set 0 background transparency
for all other views.
One way to do it -- it may not be the best -- can be that you subclass a UIView, and set the UIView instance in all of your viewControllers in the storyboard an instance of your cutomized UIView class, which contains your graphic as a background.
If you're going to tackle this programmatically, within each view controller, set:
[[self view] setBackgroundColor:[UIColor colorWithPatternImage:[UIImage imageNamed:#"background.png"]]];
in viewDidLoad
I'm sure some tweaking would allow you to apply this principle throughout the program from the app delegate, or by using a singleton.
Using this solution, though, you're still going to have to make some method call within each view controller where you want this style applied.
Related
I am trying to just do a simple view change for proof of concept.
here is the code
- (void)swipedScreen
{
if (self.secondView.superview == nil) {
[myView removeFromSuperview];
[self.view insertSubview:secondView atIndex:0];
}
}
when I swipe the screen what happens is the view area just goes black... and becomes unresponsive.
I started with a navigatoin app, replaced the tableview with just a standard uiviewcontroller class.. that worked fine..Then i added a secondView (xib only) and changed its class to match the viewcontroller of the first view.
The reason I am finding this difficult is because i am trying to animate the views inside the navigation controller and not push a whole view onto the stack which I am used to doing.
I'll bet that blank unresponsive view is, in reality, your secondView object. I always test by setting [secondView setBackgroundColor:[UIColor greenColor]] and checking if the massive green rectangle actually shows up.
EDIT: having looked at your code, there are multiple problems that arose:
You never actually +alloc or -init anything.
You never actually touch those nibs or make a reference to them in code
You declare two UIView's as IBOutlets and Strong (two exact opposites, as IBOutlets are __weak, __unsafe_unretained, or assign), yet do not link them to anything.
I've taken the liberty of revising it (sans nibs). Take a look.
Did you init the secondView? if init,you can try to set frame for the secondView
Your inserting the view at the bottom of the stack,
[self.view insertSubview:secondView atIndex:0];
Try using addSubview instead. Also you need to set the views frame somewhere.
What I want to do is a navigation bar with a image on it. I have a tab controller on my main view, and inside each tab I have a UINavigationController. From inside the UIViewController that my tab/navigationController calls, I could set the titleView without much problem, doing this inside the viewDidLoad method:
self.navigationItem.titleView = [[[UIImageView alloc] initWithImage:[UIImage imageNamed:#"mylogo.png"]] autorelease];
But, I want to replace all titles in my navigationBar for this view, and it seems ugly to repeat this everywhere. So I did this on the delegate (after linking all the Outlet stuff)
self.tabOneNavController.navigationBar.topItem.titleView = [[[UIImageView alloc] initWithImage:[UIImage imageNamed:#"mylogo.png"]] autorelease];
Again, it worked! ok, I'm almost getting there.
But the point is, I've 5 tabs and all of them have navigationControllers inside. I reduced the code repetition from every internal view to only 5 times, but it still. It requires that I do that for the NavController of each tab.
Then I tried to extend the UINavigationBar to create my own, where I could set this in the initializer, and use it in the interface builder as the object class. But it doesn't seem to work. Here is what I did:
#implementation MyNavigationBar
- (id)init {
self = [super self];
self.tintColor = [UIColor greenColor];
self.topItem.title = #"testing please work";
return self;
}
#end
in the interface file MyNavigationBar inherits from UINavigationBar. But this didn't work. Should I overwrite other method? which one? is this a good practice?
I'm not even sure if I should add one navigationBar for each tab, as I said, I have tabs and I want to have a navigation bar / navigate inside them. By now, after a near death experience trying to figure out how the interface builder / outlets and classes work, the code is working, I just would like to make unglify it.
Thank you!
The problem of repeating code which you describe has an elegant solution. Objective-C supports something called a "category", which allows you to add methods to a class. A common use for this is to customize navigation and tab bars. In Xcode 4, you would do something like this to add a category on UINavigationBar:
Hit Command+N or open the "New File" dialog. Next, choose "Objective-C category" from the Cocoa Touch menu:
Click Next and you will be prompted to enter the name of the class that you would like to add methods to as a category. It should look something like this:
Then, you should end up with a save file dialog. A quick note about convention here. Convention is to name a category after the original class, the plus sign, and then a description of what you're adding. Here's what yours might look like:
Once you save your file, you will need get something like this:
Look at that beauty. You can now override the default drawing/init methods as well as extend the functionality of the navbar.
I'd suggest looking into the init and drawRect methods, although I don't remember which ones people use. Also, please note that while under NDA, this may change in iOS 5, so just be prepared for that possibility.
Why not define a UIViewController subclass which sets the title view via self.navigationItem.titleView and have your other view controllers extend from that class? Then you're sharing that behavior across all of your controllers without repeating the implementation.
probably a very simple question but can't find the right answer anywhere. I am using XCode 4 and working on an iphone app, which probably sums up all the info that I need to provide.
Here it is:
- I created a ViewBasedApplication
- At some point depending on the user input, I load a TableView
But now how on Earth do I add a button or something to return? Note: I can't use a NavigationBased app, that would be easier but would not work for me.
Help anyone?
If you used a UITableViewController, you may want to use a UIViewController instead. In the UIVeiwController, you can add a UITableView along with your own UINavigationBar or, if you don't want to use a UINavigationBar, you could leave room for some type of custom UIButton. Either the UINavigationBar button or your custom UIButton action could trigger a close of your UIViewController.
If you add the UIViewController as a subview, then Cyprian's [self removeFromSuperView]; would work. If you present as a modal as Jamie suggests, you could use [self dismissModalViewControllerAnimated:YES];.
Well I don't know you code but you could always call
[self removeFromSuperView];
Developing an iPhone app.
I've got a really strange problem where, every once in a while, the status bar at the top of my app screen will turn solid black. Not like the black version of the status bar, but like a solid black rectangle with NO text/icons. It's very rare, but usually seems to occur after returning to the app via multi-tasking or from a locked device (the app has been running in the background). I've seen it occur on both 3GS and iPhone4. Here's a screenshot:
I can never reproduce it when trying, it just seems to eventually happen at some point (sometimes it will go for days without happening).
Once it does occur, the app seems to continue functioning fine, even with the status bar gone, except for when I do one specific action in the app which will cause everything to freeze up all the sudden (the app doesn't crash, but everything on screen is frozen and non-interactive). Without explaining the design in detail, the specific action that causes it to freeze up (after the bug appears) is performing a simple upload in the background to a SQL database. Resetting the app is the only way to fix the problem once the black status bar appears.
Anyone else ever experienced this? I can't find a single thread anywhere explaining similar behavior, and it's driving me nuts.
It happened once in my app when I called a drawing method in my custom subclass of UIView instance right before I added it as a subview to parent view.
The solution was apparently easy: add it as a subview first before sending/calling any custom drawing methods.
Examples:
CustomView *aView = [[CustomView alloc] init];
[aView drawSomething];
[self.view addSubview:aView]; //wrong approach
[aView release];
Should be:
CustomView *aView = [[CustomView alloc] init];
[self.view addSubview:aView];
[aView release];
[aView drawSomething];
The screenshot is missing, but what you describe sounds as though you've incorrectly implemented the use of Apple's built-in view controllers.
Both UINavigationController and UITabBarController will automagically shift all the content inside them down by 20-pixels, if they detect there is "supposed" to be a statusbar on screen at the moment.
My guess is that you have some code that is removing the statusbar, but which is kicking-in after the Apple code has already detected it and shifted everything down to accomodate.
The "fix" is to re-read the docs on Apple's classes very carefully and use them as Apple dictates (usually, people use them in ways that seem sensible - e.g. embedding them inside other views - but which Apple has expressly declared are unsupported. Sadly those classes from Apple are very fragile)
Are you holding a reference to a QLPreviewController instance? I was able to solve this problem in my app by creating a new autoreleased QLPreviewController whenever I need to display a file modally, as opposed to reusing the same instance over and over again.
I had a similar problem, which I described in this question here
If you have any, try removing any CGRect frame created by reference to:
[UIScreen mainScreen].applicationFrame]
and instead create the frame using a more manual definition. If that works, you can decide how to proceed from that point.
I'm trying to create a custom transition, to serve as a replacement for a default transition you would get here, for example:
[self.navigationController pushViewController:someController animated:YES];
I have prepared an OpenGL-based view that performs an effect on some static texture mapped to a plane (let's say it's a copy of the flip effect in Core Animation). What I don't know how to do is:
grab current view content and make a texture out of it (I remember seeing a function that does just that, but can't find it)
how to do the same for the view that is currently offscreen and is going to replace current view
are there some APIs I can hook to in order to make my transition class as native as possible (make it a kind of Core Animation effect)?
Any thoughts or links are greatly appreciated!
UPDATE
Jeffrey Forbes's answer works great as a solution to capture the content of a view.
What I haven't figured out yet is how to capture the content of the view I want to transition to, which should be invisible until the transition is done.
Also, which method should I use to present the OpenGL view?
For demonstration purposes I used pushViewController. That affects the navbar, though, which I actually want to go one item back, with animation, check this vid for explanation:
http://vimeo.com/4649397.
Another option would be to go with presentViewController, but that shows fullscreen.
Do you think maybe creating another window (or view?) could be useful?
While I cannot completely answer your question without doing some more research of my own, I can help a bit:
-In order to get the view of a UINavigationController, you need to take a screenshot. The easiest way to do this is by grabbing it into a UIImage:
UIGraphicsBeginImageContext(self.view.frame.size);
[[self.view layer] renderInContext:UIGraphicsGetCurrentContext()];
UIImage* test = UIGraphicsGetImageFromCurrentImageContext();
UIImageView* view = [[UIImageView alloc] initWithImage:test];
UIGraphicsEndImageContext();
I am not sure if you can render a GLContext (not familiar on the phone) into a CGImage, but I would do something like that (and init a UIImage from that). I would prerender every frame of the animation you are trying to do and slap it into an UIImageView using the animation stuff provided within. That is, if your animation is simple enough. Otherwise, it might come down to writing your own animation function :-/
I have just put together a transition class to implement your own transition animation in OpenGL ES.
Feel free to read about it here
There are two example transitions in the project, feel free to add you own to it.
I think the function you might be thinking of is http://www.opengl.org/sdk/docs/man/xhtml/glCopyTexImage2D.xml ... you set the viewport to the texture size and then draw as usual, then do glCopyTexImage2D to copy the scene onto a texture.
or you should look into FrameBuffer Objects. The default OpenGL template in XCode uses these. Just generate the example project to see how those work.
I recently write some transitioning animation betweeen view controllers like you. If you want to get any extra info from the invisible view, you can try delaying the transition like this :
- (void)animationFromModalView:(UIView *)modalView toMasterView:(UIView *)masterView
{
[masterView setNeedsLayout];
[masterView layoutIfNeeded];
[self performSelector:#selector(delayAnimationFromModalViewToMasterView) withObject:nil afterDelay:.1f];
}