UINavigationBar Back button with no text, ever - cocoa-touch

I have a requirement in a project that the UINavigationBar Back button should never have text in it, it should always just be a left arrow.
By default iOS is going to insert the title of the previous controller in there. Is there any way I can stop this from happening across the whole app?
(I know I can do this screen by screen, but I'm working on an existing app with A LOT of screens it and this would be a big job)

You can always set an image of an arrow to left bar button of navigation bar
// ADDING IMAGE TO BUTTON
UIButton *refreshButton = [UIButton buttonWithType:UIButtonTypeCustom];
[refreshButton setFrame:CGRectMake(0,0,30,30)];
[refreshButton setImage:[UIImage imageNamed:#"arrow_image.png"] forState:UIControlStateNormal];
refreshButton.userInteractionEnabled=NO;
// ASSIGNING THE BUTTON WITH IMAGE TO LEFT BAR BUTTON
UIBarButtonItem *refreshBarButton = [[[UIBarButtonItem alloc] initWithCustomView:refreshButton] autorelease];
self.navigationItem.leftBarButtonItem = refreshBarButton;
You will have to write this in each view controller in order to disable default left bar button.

You can't stop it from happening across the whole app, you'll have to set it manually in each controller. You could use a category on UIViewController and call that method in each controller, which will get you down to 1 line of code that doesn't have to change if you change your approach. Still sucks, I know. Also, you will probably have issues with Apple if you do that. We tried that in one of our apps and when I showed it to the Apple guys at WWDC '13 they flat out told me they would reject the app if I submitted it that way. YMMV

Related

How does a UIAlertView determine the vertical and horizontal center of the view it's within?

I'd like to use this same solution with my UIView to get the same result.
I have a UIView with a UIScrollView. These are embedded in a UINavigationController.
A customer adds an item to their basket and I would like to give them a confirmation message. Right now a little basket UIBarButtonItem updates a title within to show the number of items. This is fine but not every user/customer will notice this.
I don't really like the style of a UIAlertView for this situation. So I'm going to add my own UIView and style it how I want to.
I'm trying to figure out how to get the UIView to show up in the center of the window. Whether the customer is using an iPhone4 or iPhone5.
UIView code:
UIView *confirmationPopup = [[UIView alloc] initWithFrame:CGRectMake(10, 200, 300, 100)];
[confirmationPopup setBackgroundColor:[UIColor redColor]];
// confirmationPopup.center = [confirmationPopup.superview convertPoint:confirmationPopup.superview.center fromView:confirmationPopup.superview.superview];
[[[self navigationController] view] addSubview:confirmationPopup];
The popup view is centered horizontally automatically but not vertically. I've tried to play around with the line you can see I've commented out but it doesn't center the UIView in the center of the window. It appears to be centering it inside the NavBar
Would appreciate some solutions.
Don't hard-code; use auto layout. You might be helped by my custom class for this purpose, an imitation alert view substitute that you can configure however you like. It takes advantage of iOS 7 custom presentation view transitions. (Of course in iOS 8 there will be even more support for this kind of thing, i.e. UIPresentationController.)

UIKeyboard in iOS7

I'm using Xcode 5 and the iOS7 SDK to build my app. I am wanting to make a sign in page very similar to that of the iOS7 eBay app.
So what I would like to do is this:
When the ViewController loads, I would like two UIButtons just above the keyboard
Once the user has finished entering their information and hitting the done button - the keyboard disappears and background animates very slightly to show a logo at the top.
I'm thinking I should be listening for UIKeyboard notifications and then do things based on that.
Here are my questions:
I am sure I can change the background image, based on the UIKeyboard notification status - how do I make it animate ? I don't want it to just appear?
How do I position the UIButtons correctly to sit by the keyboard ?
You should use the UIToolBar and set it as inputaccessoryview to the textFields.
Here is one clean & clear solution for this problem.
Blog Post here
For backGround animation please use this.
May be you can set the background logo alpha = 0 initially.
[UIView animateWithDuration:0.7 animations:^{
self.view.logoImage.alpha = 1;
// make some more movements for anything that suits to your need.
// set frame of your textFields & any thing else that you need.
}
completion:^(BOOL finished){
// may be you can load a new view controller here.
}];
Hope that helps.

iOS7 custom interactive transition, hidden back button reappears as "..." when cancelled

I have a custom interactive transition which requires me to hide the standard back button. Basically, the transition looks like a push from left-to-right rather than the standard right-to-left push we're all familiar with. That's why my back button is on the right side instead.
As you can see from two screenshots I took before and after cancelling pop transition activated by a UIScreenEdgePanGestureRecognizer, once the transition is cancelled there is a "..." where the back button would be.
I'm currently using
self.navigationItem.hidesBackButton = YES;
and I've tried putting it in awakeFromNib, viewDidLoad, viewDidAppear, viewWillAppear methods all without fixing the problem.
So using the power of Reveal.app I investigated the view hierarchy before and after and saw this:
What you see highlighted in each part of the image is what appears to be changing in the area of the nav bar that contains the hidden back button. Before it's a UINavigationButton and then it becomes a UINavigationButtonItem with a UILabel, which must be what contains the "..." and remains like this.
Any help would be much appreciated. I hope this is detailed enough to give a good picture of the issue.
Try creating an empty backbutton first (in the parent viewcontroller before the vc is pushed) - maybe that will prevent the "..." UILabel from being created.
self.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc]
initWithTitle:#""
style:UIBarButtonItemStyleBordered
target:nil
action:nil];
Another idea: Just set the parent vc title to an empty string.
self.title = #"";

Rotating UITabBarController Icon

I have an UITabBar in my application. One of the tab bar icons looks like a loading symbol. When the user presses the loading button I want the icon to spin/rotate until the loading is done. Should I use UIImageView to animate or something else? How should I make this happen?
Jacos, unfortunately you cannot do that with the UITabBarController and manipulate the tabBarController's tabBar properties. My best bet would be that you use a UIToolBar and assign a black color and make it appear like a tabBar and have buttons added in them as a subView so that they look like tabBarItems.
Its much more customizable, and you can even provide a scrolling experience and add more buttons to it.
I know this question is 4 years old but I had the same problem and managed to fix it by reading the tutorial in here:
https://medium.com/#werry_paxman/bring-your-uitabbar-to-life-animating-uitabbaritem-images-with-swift-and-coregraphics-d3be75eb8d4d#.bjfpbdnut
The main point is to get the view for desired UITabBarItem and the get the UIImageView from it in viewDidLoad:
UIView *plusView = self.tabBar.subviews[1];
self.plusImageView = plusView.subviews.firstObject;
self.plusImageView.contentMode = UIViewContentModeCenter;
Then in didSelectItem method you can do this:
[UIView animateWithDuration:0.4 animations:^{
[self.plusImageView setTransform:CGAffineTransformMakeRotation(M_PI/4)];
}];
My code only rotate the image view for 45 degrees but you can change as you wish.
I guess you could change the UITabBarItem's icon on a timer, but that seems pretty kludgey. You would have to pre-render each frame of your "loading" icon rather than rotate an ImageView.
Another hackey solution would be to add your ImageView to the UIWindow and move it on top of the TabBarController's TabBar (adding it to the TabBar itself is asking for trouble).
You shouldn't try to animate the actual UIImageView within the UITabBarController. I would take this approach:
Set the image for the relevant tab to nil or a blank image.
Create a UIActivityIndicatorView and add it over the tab bar. Position it over the correct tab.
[self.tabBarController.tabBar addSubview:activityIndicatorView];
When your loading task has completed, restore the normal image to the tab and remove the activityIndicator from the tab bar.

UIButton's target is fired before animation

I have programmed a Quiz in Xcode where I've created UIButtons programmatically displaying the answer to a question. When the user clicks the button the next question is loaded and the buttons position i shuffled to not make the right answer in the same place for each question (the right answer is however under the same UIButton for every question.)
This is how I create my buttons:
if (self.buttonRightAnswer == nil)
{
self.buttonRightAnswer = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[self.buttonRightAnswer addTarget:self action:#selector(rightAnswer) forControlEvents:UIControlEventTouchDown];
[self.view addSubview:self.buttonRightAnswer];
}
self.buttonRightAnswer.frame = CGRectMake(20.0, [[randomPositionArray objectAtIndex:0] floatValue], 280.0, 40.0);
[self.buttonRightAnswer setTitle:[[self.quiz.arrayWithQuestions objectAtIndex:questionNr - 1]valueForKey:#"RightAnswer"] forState:UIControlStateNormal];
When the user clicks the right an answer the next question loads. Here it's a problem. The next question loads with the same method only shuffled positions and the animation of the press-down of the button is drawn after the buttons been moved resulting in the user seeing where the right answer is now.
How can I wait for the animation before moving the buttons?
I could solve this by having the buttons stay in one place, shuffling out the questions over the buttons and comparing the users answer with the right answer.. but this requires a hell of a lot more code.
You can use some of shit-code and insert some kind of 'sleep' before next shuffling buttons
Before you create the buttons againg (after a question was answered), you can add something like (if you use differen images for button states)
-(void)waitUntilButtonDeselected
{
bool selected = YES;
while (selected)
{
bool selected = (self.buttonRightAnswer.currentBackgroundImage == UIImageOfNotSelectedButton);
}
}
The idea here is to check if the image of the button corresponds to not selected button.
Typically when using a UIButton, events are triggered on UIControlEventTouchUpInside, or at the end of the touch.
You're triggering it on the touch down which is causing issues with the animation you want to happen.
It might be simpler for you to switch to using UIControlEventTouchUpInside instead of UIControlEventTouchDown since this should solve your problem and be more consistent with other iPhone apps.