Instantiate View behind current ViewController - iphone

I want to instantiate a viewController and place it behind the currently shown view. Then move the original view's fram to reveal the view behind it.
I CANNOT create the bottom view first and add the top view on top. I will be creating multiple bottom views and memory can't handle the whole stack at once.
Problems I've already encountered.
Adding a subView and sending it to the back means moving the original view's frame move's the entire view, not revealing the new one.
Instantiating the new view and calling presentViewController deallocs the original view (if I add it modally)
Can anyone help? Or lead me in a direction?

Is it fair to say you're going for a transition from vc1 to vc2 where what you want is the appearance that vc2 was underneath vc1 and vc1 slid out of the way to reveal it?
If so, then that's doable without doing anything unusual or dangerous from the sdk perspective. The trick is to do the normal instantiate and present steps, but in vc1, before presenting vc2, hand it a UIImage that looks like vc1. Vc2 covers itself with that image before it appears, then slides the image out of the way to reveal itself.
Here are the steps:
1) On vc1, implement the method in this post. It captures an image of the view.
2) There's some action that makes you want to present vc2, do it like this...
- (void)presentVc2:(id)sender {
UIImage *image = [self makeImage]; // it was called makeImage in the other post, consider a better name
MyViewController2 *vc2 = [[MyViewController2 alloc] initWithNibName:#"MyViewController2" bundle:nil];
vc2.presentationImage = image; // more on this later
// this line will vary depending on if you're using a container vc, but the key is
// to present vc2 with NO animation
[self presentViewController:vc2 animated:NO completion:^{}];
}
3) Create a UIImage property on MyViewController2 called presentationImage and make it's setter public. Then in MyViewController2 ...
// before we appear, cover with the last vc's image
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
UIImageView *imageView = [[UIImageView alloc] initWithImage:self.presentationImage];
imageView.frame = self.view.bounds;
imageView.tag = 128;
[self.view addSubview:imageView];
}
// after we appear, animate the removal of that image
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
UIImageView *imageView = (UIImageView *)[self.view viewWithTag:128];
[UIView animateWithDuration:0.5 animations:^{
imageView.frame = CGRectOffset(imageView.frame, -self.frame.size.width, 0);
}];
}

You could simply put the top view's contents into a new UIView whose frame is equal to your view controller's view's frame. Then stick your bottom views below the container view. Moving the container view, then, will move all of its contents but leave the bottom views in tact.

Related

resize view to the right height after adding it to a uinavigationcontroller

so i've go a uiviewcontroller (with its default view) that i created programmatically like
TestViewController *aVC = [[MJImageCropViewController alloc] init];
[[self navigationController] pushViewController:aVC animated:YES];
inside it there is something like this in the viewDidLoad
self.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
the problem is, that the height of the view of the pushedViewController remains 460px but visible is only 416px (because of the existing navigationController.
is there a way to let the uiview of the pushed viewcontroller resize the right way without setting explicit the frame to 416 (because of rotation and so on)?
You may want to try something like this in -viewDidLoad:
- (void)viewDidLoad {
[super viewDidLoad];
// Resize view to account for nav bar
CGFloat navBarHeight = self.navigationController.navigationBar.bounds.size.height;
CGRect frame = self.view.frame;
frame.size.height = frame.size.height - navBarHeight;
self.view.frame = frame;
}
My guess is that the view is being resized correctly, but it's subview's autoresizing masks are not set properly. Also, it makes a lot more sense to place the autoresize code you posted either in loadView (if you are creating the view programmatically) or in the XIB file.
Try to log out the view controller's frame at the end of viewDidLoad via
NSLog(#"%#",NSStringFromCGRect(self.view.frame));
And see what that tells you.

Send subview to back

I'm trying to mimic the facebook ios side menu and have it working however the issue I am having is that I cannot send the sidemenu to the back as discussed in another question on SO iphone facebook side menu using objective c. I'm not using the library suggested but instead using the code that was suggested. I have
- (void)viewDidLoad
{
NSLog(#"View Did Load is running");
activitySpinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
activitySpinner.frame = CGRectMake(0.0, 0.0, 40.0, 40.0);
activitySpinner.center = self.view.center;
[self.view addSubview:activitySpinner];
SideMenuView *myDelegate = [[SideMenuView alloc] init];
[self setSideMenuDelegate:myDelegate];
//set the delegate's currentViewController property so that we can add a subview to this View.
[sideMenuDelegate setCurrentViewController:self];
//sideMenu = [[SideMenuView alloc] initWithNibName:#"SideMenuView" bundle:nil];
[self.view addSubview:myDelegate.view];
[self.view sendSubviewToBack:myDelegate.view];
[super viewDidLoad];
self.searchDisplayController.searchBar.scopeButtonTitles = nil;
[self fetchCustomers];
// Do any additional setup after loading the view, typically from a nib.
}
In my controller where I want the side menu but the view seems to get loaded into the current view instead of just going to the back so it can be seen when I slide the menu over.
Can someone help me get the myDelegate view to the back?
I am not entirely sure what you are trying to accomplish, so I have to guess. It sounds like you want to hide myDelegate.view behind self.view. It won't work this way.
sendSubviewToBack: sends the subview to the back of the view hierarchy of the sender, in your case, self.view. It will never send a subview below its superview.
You can instead add myDelegate.view as a subview to self.views superview, and put it behind self.view:
[[self.view superview] insertSubview:myDelegate.view belowSubview:self.view];
I've decided to just go with https://github.com/Inferis/ViewDeck and let that manage the views.

ipad second start screen

i like to create a second starting screen in my app.
My Idea is to use the default.png and load an UIView with an fullscreen UIImageView inside.
In viewDidLoad i thought about placing a sleep option and after this load the real app screen.
But also when my function is called in viewDidLoad, nothing happens.
Seems my superview is empty...
Here is a piece of code:
if (self._pdfview == nil)
{
pdfview *videc = [[pdfview alloc]
initWithNibName:#"pdfview" bundle:nil];
self._pdfview = videc;
[pdfview release];
}
// get the view that's currently showing
UIView *currentView = self.view;
// get the the underlying UIWindow, or the view containing the current view
UIView *theWindow = [currentView superview];
theWindow is empty after this line so that might be the reason why the other view is not loaded.
So my question, how do i create a second starting screen ?
Or three starting screens, like in games when i like to mention another company.
If I understand correctly, your point is that when your function above is executed from viewDidLoad of some controller, theWindow is nil, so your new view (startscreen) is not added to it.
A few observations:
if theWindow is nil, then self.view is the topmost UIView; you can try and replace it, or simply add your view to it:
UIView *currentView = self.view;
// get the the underlying UIWindow, or the view containing the current view
UIView *theWindow = [currentView superview];
UIView *newView = _pdfview.view;
if (theWindow) {
[currentView removeFromSuperview];
[theWindow addSubview:newView];
} else {
self.view = newView; //-- or: [self.view addSubview:newView];
}
if you want to get the UIWindow of your app (which seems what you are trying to do), you can do:
[UIApplication sharedApplication].keyWindow;
and from there you can either set the rootViewController (from iOS 4.0)
[UIApplication sharedApplication].keyWindow.rootViewController = ...;
or add newView as a subview to it:
[[UIApplication sharedApplication].keyWindow addSubview:newView];
in the second case, you should possibly remove all subviews previously added to the UIWindow. (Iterate on keyWindow.subviews and call removeFromSuperview).
OLD ANSWER:
I think that you should try and add your pdfview as a subview to the current view:
[currentView addSubview:videc];
or to what you call theWindow:
[theWindow addSubview:pvidec];
and, please, move the release statement after the `addSubview, otherwise the view will be deallocated immediately.

switch between uiviews with buttons and not uinavigation controllers

I have seen the post for How to switch views by buttons on iPhone? but this doesn't answer how to switch back and forth between views with buttons. The person that asked the question settled on the answer that they could switch between views with uinavigationcontroller.
I put the following code in an ibaction that kicks off when a button is pressed in the primary view.
PhoneNumberViewController *phoneNumberViewController1 = [[PhoneNumberViewController alloc] initWithNibName:#"PhoneNumberView2" bundle:nil];
self.phoneNumberViewController = phoneNumberViewController1;
[self.view removeFromSuperview];
[self.view insertSubview: phoneNumberViewController1.view atIndex:0];
When this code executes the whole view just goes blank. If I omit the removefromsuperview portion then the view disappears behind my button but the button still remains. I'm not sure if this is the right way to switch between buttons but if anyone knows how to do this please help. Also if anyone knows about any example projects that switch between views with buttons let me know.
Thanks a million!
You removed the view controller's view from it's superview and then added a subview to it. The view hierarchy is broken at the view controller's superview (likely your window). That is why you are getting a blank screen.
You'd likely want to keep a reference around to the original view and then swap it out to the new view by setting the view controller's view to the new view.
// origView is an instance variable/IBOutlet to your original view.
- (IBAction)switchToPhoneView:(id)sender {
if (origView == nil)
origView = self.view;
self.view = phoneViewController.view;
}
- (IBAction)switchToOriginalView:(id)sender {
self.view = origView;
}
The technique I usually use involves creating a superview class which contains a toolbar at the bottom, and a content view UIView class filling the rest of the screen.
I then add subviews to the content view to change the views based on button clicks. This approach makes it so the toolbar on the same is constant across all views. I start by defining a helper function like this:
-(void) clearContentView {
//helper to clear content view
for (UIView *view in [self.contentView subviews]){
[view removeFromSuperview];
}
}
My IBAction then looks like this:
-(IBAction) buttonClicked{
self.title = #"Images"; //change title of view
[self clearContentView]; //clear content view
[self.contentView addSubview:self.imagesViewController.view]; //add new view
[self.imagesViewController viewWillAppear:YES]; //make sure new view is updated
[self enableButtons]; //enable all other buttons on toolbar
self.imagesButton.enabled = NO; //disable currently selected button
}

Transparent Modal View on Navigation Controller

I'm trying to create a transparent modal View on top of my navigation controller. Does anyone know if this is possible?
A modal view will cover the view it is pushed on top of as well as the navigation bar for your navigation controller. However, if you use the -presentModalViewController:animated: approach, then once the animation finishes the view just covered will actually disappear, which makes any transparency of your modal view pointless. (You can verify this by implementing the -viewWillDisappear: and -viewDidDisappear: methods in your root view controller).
You can add the modal view directly to the view hierarchy like so:
UIView *modalView =
[[[UIView alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
modalView.opaque = NO;
modalView.backgroundColor =
[[UIColor blackColor] colorWithAlphaComponent:0.5f];
UILabel *label = [[[UILabel alloc] init] autorelease];
label.text = #"Modal View";
label.textColor = [UIColor whiteColor];
label.backgroundColor = [UIColor clearColor];
label.opaque = NO;
[label sizeToFit];
[label setCenter:CGPointMake(modalView.frame.size.width / 2,
modalView.frame.size.height / 2)];
[modalView addSubview:label];
[self.view addSubview:modalView];
Adding the modalView as a subview to the root view like this will not actually cover the navigation bar, but it will cover the entire view below it. I tried playing around with the origin of the frame used to init the modalView, but negative values cause it to not display. The best method that I found to cover the entire screen besides the status bar is to add the modalView as a subview of the window itself:
TransparentModalViewAppDelegate *delegate = (TransparentModalViewAppDelegate *)[UIApplication sharedApplication].delegate;
[delegate.window addSubview:modalView];
The easiest way is to use modalPresentationStyle property of navigationController (but you'll have to make animation by yourself):
self.navigationController.modalPresentationStyle = UIModalPresentationCurrentContext;
[self presentModalViewController:modalViewController animated:NO];
modalViewController.view.alpha = 0;
[UIView animateWithDuration:0.5 animations:^{
modalViewController.view.alpha = 1;
}];
I accomplish this most easily by setting up an "OverlayViewController" that sits above all other subviews of my window or root view. Set this up in your app delegate or root view controller, and make OverlayViewController a singleton so that it can be accessed from anywhere in your code or view controller hierarchy. You can then call methods to show modal views, show activity indicators, etc, whenever you need to, and they can potentially cover any tab bars or navigation controllers.
Sample code for root view controller:
- (void)viewDidLoad {
OverlayViewController *o = [OverlayViewController sharedOverlayViewController];
[self.view addSubview:o.view];
}
Sample code you might use to display your modal view:
[[OverlayViewController sharedOverlayViewController] presentModalViewController:myModalViewController animated:YES];
I haven't actually used -presentModalViewController:animated: with my OverlayViewController but I expect this would work just fine.
See also: What does your Objective-C singleton look like?
I had this same problem and in order to The solution is to add the modal view with addSubview: and animate the change in the view hierarchy with UIView’s animateWithDuration:delay:options:animations:completion:
I added a property and 2 methods to a subclass of UIViewController (FRRViewController) that includes other functionalities. I will be publishing the whole stuff on gitHub soon, but until then you can see the relevant code below. For more info, you can check my blog: How to display a transparent modal view controller.
#pragma mark - Transparent Modal View
-(void) presentTransparentModalViewController: (UIViewController *) aViewController
animated: (BOOL) isAnimated
withAlpha: (CGFloat) anAlpha{
self.transparentModalViewController = aViewController;
UIView *view = aViewController.view;
view.opaque = NO;
view.alpha = anAlpha;
[view.subviews enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
UIView *each = obj;
each.opaque = NO;
each.alpha = anAlpha;
}];
if (isAnimated) {
//Animated
CGRect mainrect = [[UIScreen mainScreen] bounds];
CGRect newRect = CGRectMake(0, mainrect.size.height, mainrect.size.width, mainrect.size.height);
[self.view addSubview:view];
view.frame = newRect;
[UIView animateWithDuration:0.8
animations:^{
view.frame = mainrect;
} completion:^(BOOL finished) {
//nop
}];
}else{
view.frame = [[UIScreen mainScreen] bounds];
[self.view addSubview:view];
}
}
-(void) dismissTransparentModalViewControllerAnimated:(BOOL) animated{
if (animated) {
CGRect mainrect = [[UIScreen mainScreen] bounds];
CGRect newRect = CGRectMake(0, mainrect.size.height, mainrect.size.width, mainrect.size.height);
[UIView animateWithDuration:0.8
animations:^{
self.transparentModalViewController.view.frame = newRect;
} completion:^(BOOL finished) {
[self.transparentModalViewController.view removeFromSuperview];
self.transparentModalViewController = nil;
}];
}
}
Here's what I did to solve the problem - Google the details but this approach worked very well for me:
Take a screenshot of the underlying view. https://devforums.apple.com/message/266836 - this leads to a ready-made method that returns a UIView for the current screen.
Hand the screenshot to the modal view (I used a property)
Present the modal view
In the modal view controller's viewDidAppear, set the image as UIImageView at index 0. Adjust the vertical position of the image by the height of the status bar.
In the modal view controller's viewWillDisappear, remove the image again
The effect is:
The view animates in as any modal view does - the semi transparent parts of the modal view glide over the existing view
As soon as the animation stops, the background is set to the screenshot - this makes it appear as if the old view is still underneath even though it isn't.
As soon as the modal view's disappear animation starts, the image is removed. The OS meanwhile shows the old navigation view so the modal view transparently glides away and out of sight as you'd expect.
I tried animating in my own overlay view but it didn't work very well. I got a crash with no indication as to what has crashed. Rather than chase this down I did the bg view & Works really well.
Code in the modal view - I think you can figure out the rest, namely setting the property modalView.bgImage...
- (void)viewDidAppear:(BOOL)animated {
// background
// Get status bar frame dimensions
CGRect statusBarRect = [[UIApplication sharedApplication] statusBarFrame];
UIImageView *imageView = [[UIImageView alloc] initWithImage:self.bgImage];
imageView.tag = 5;
imageView.center = CGPointMake(imageView.center.x, imageView.center.y - statusBarRect.size.height);
[self.view insertSubview:imageView atIndex:0];
}
- (void)viewWillDisappear:(BOOL)animated {
[[self.view viewWithTag:5] removeFromSuperview];
}
self.modalPresentationStyle = UIModalPresentationCurrentContext;
[self presentModalViewController:newview animated:YES];
and make sure you setup the modal view background to be transparent,
self.view.background = .... alpha:0.x;
if you set modalPresentationStyle for the modal view controller to:
viewController.modalPresentationStyle = 17;
The view in the background is not removed. (TWTweetComposeViewController use it).
I did not try to pass App Store review with this code though
This post about displaying a semi-transparent "Loading..." view might give a few pointers on how to proceed.
Yeah, you have to add the view manually, and if you want to slide in from the bottom or whatever you have to do the animation yourself too.
I wrote a class to do this, and a semi-modal datepicker using that class as an example.
You can find documentation in this blog post, the code is on github
I've been researching this same issue for the past week. I tried all the various answers and examples found in Google and here on StackOverflow. None of them worked that well.
Being new to iOS programming, I wasn't aware of something called UIActionSheet. So if you're trying to accomplish this in order to show a modal overlay of buttons (such as a modal asking someone how they want to share something), just use UIActionSheet.
Here is a webpage that shows an example of how to do this.
I got this idea from https://gist.github.com/1279713
Prepare:
In the modal view xib (or scene using storyboard), I setup the full-screen background UIImageView (hook it with the .h file and give it a property "backgroundImageView") with 0.3 alpha. And I set the view (UIView) background color as plain black.
Idea:
Then in "viewDidLoad" of the modal view controller I capture the screenshot from the original status and set that image to the background UIImageView. Set the initial Y point to -480 and let it slide to Y point 0 using 0.4-second duration with EaseInOut animation option. When we dismiss the view controller, just do the reverse thing.
Code for the Modal View Controller Class
.h file:
#property (weak, nonatomic) IBOutlet UIImageView *backgroundImageView;
- (void) backgroundInitialize;
- (void) backgroundAnimateIn;
- (void) backgroundAnimateOut;
.m file:
- (void) backgroundInitialize{
UIGraphicsBeginImageContextWithOptions(((UIViewController *)delegate).view.window.frame.size, YES, 0.0);
[((UIViewController *)delegate).view.window.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage * screenshot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
backgroundImageView.image=screenshot;
}
- (void) backgroundAnimateIn{
CGRect backgroundImageViewRect = backgroundImageView.frame;
CGRect backgroundImageViewRectTemp = backgroundImageViewRect;
backgroundImageViewRectTemp.origin.y=-480;
backgroundImageView.frame=backgroundImageViewRectTemp;
[UIView animateWithDuration:0.4 delay:0.0 options:UIViewAnimationCurveEaseInOut animations:^{
backgroundImageView.frame=backgroundImageViewRect;
} completion:^(BOOL finished) {
}];
}
- (void) backgroundAnimateOut{
CGRect backgroundImageViewRect = backgroundImageView.frame;
backgroundImageViewRect.origin.y-=480;
[UIView animateWithDuration:0.4 delay:0.0 options:UIViewAnimationCurveEaseInOut animations:^{
backgroundImageView.frame=backgroundImageViewRect;
} completion:^(BOOL finished) {
}];
}
In viewDidLoad, simply call:
[self backgroundInitialize];
[self backgroundAnimateIn];
In anywhere we dismiss the modal view controller, we call:
[self backgroundAnimateOut];
Please note that this will ALWAYS animate the background image. So if this modal view controller transition style (or the segue transition style) is not set to "Cover Vertical", you may not need to call the animation methods.
I finally accomplished this, for a navigation or tab bar interface, by combining an overlay view controller (see: pix0r's answer) that's hidden / un-hidden before hiding or showing a view controller based on this very good blog post.
Concerning the view controller, the tip is to make its background view the clearColor, then the semi-transparent overlay view is visible and whatever views are added as subviews in the view controller are in front and most importantly opaque.
I've created open soruce library MZFormSheetController to present modal form sheet on additional UIWindow. You can use it to present transparency modal view controller, even adjust the size of the presented view controller.
For iOS 8+ you can use UIModalPresentationOverCurrentContext presentation style for presented view controller to easy achieve desired behavior.
UIViewController *viewController = [[UIViewController alloc] init];
viewController.view.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent:0.9f];
viewController.modalPresentationStyle = UIModalPresentationOverCurrentContext;
[self presentViewController:viewController animated:YES completion:nil];
If you also need to support iOS 7 - check this thread.
You can achieve transparent/semi-transparent modal view effect by overlaying a transparent/semi-transparent button on both the view and the navigation bar.
You can access the navigation bar through the navigationBar property of the UINavigationController.
I found that UIButton unlike UILabel will trap mouse events - hence giving the correct modal behavior.
I just found a workaround for that. Just create a 1X1 of UIViewController and add it to your parent view controller. And show the transparent modal view controller in that UIViewController.
on viewDidLoad;
self.dummyViewController = [[UIViewController alloc] init];
[self.dummyViewController.view setFrame:CGRectMake(0, 0, 1, 1)];
[self.view addSubView:self.dummyViewController.view];
when you need to open a transparentViewController;
[self.dummyViewController presentModalViewController:yourTransparentModalViewController animated:true];
If you need a screen like the attached one, the below code may help you.
The code:
MyViewController * myViewController = [[MyViewController alloc] initWithNibName:nibName bundle:nil];
UINavigationController * myNavigationController = [[UINavigationController alloc] initWithRootViewController: myViewController];
myNavigationController.modalPresentationStyle = UIModalPresentationPageSheet;
[self presentModalViewController: myNavigationController animated:YES];
If say you want a screen overlay, use the parentViewController.view, it will place above navigation bar ++
MyCustomViewController* myOverlayView = [[MyCustomViewController alloc] init];
[self.parentViewController.view addSubview:myOverlayView];
This worked for me:
UIViewController *modalViewController = [[UIViewController alloc] init];
modalViewController.view.backgroundColor = [UIColor whiteColor] colorWithAlpha:0.5];
[self showDetailViewController:modalViewController sender:nil];