In my app I habe a view controller that calls several views. All these views are UIViews. That works fine, but not in every case. One of the views that are called has some labels, textfields and two UITextViews. Everything is shown correctly but the UITextViews. The view is called in that way:
[[self view] addSubview:tasteView];
//tasteView = [[TasteView alloc] init];
[self setCurrentView:tasteView];
I call the init method of the view to display the UITextViews:
EDIT: After a comment of Phillip Mills this was slightly changed! Init isn't called anymore.
- (id)init
{
if (self)
{
[tv1 setNeedsDisplay];
CGRect frame = tv1.frame;
frame.size.height += 1;
tv1.frame = frame;
}
return self;
}
As I saw that setNeedsDisplay had no effect, I changed the size of the corresponsing frame to force a redraw. Unfortunately that had no effect, too.
Btw, the view is initially loaded in the viewDidLoad of the view controller:
- (void)viewDidLoad
{
[super viewDidLoad];
[self setCurrentView:placeholder];
[self configureView];
wineryView = [self loadWineryView];
wineView = [self loadWineView];
tasteView = [self loadTasteView];
}
A method for loading the views looks like this:
- (UIView *) loadTasteView
{
NSArray *nibViews = [[NSBundle mainBundle] loadNibNamed:#"TasteView" owner:self options:nil];
UIView *tView;
for (id view in nibViews)
{
if ([view isKindOfClass:[TasteView class]])
{
tView = (TasteView*) view;
}
}
return tView;
}
I do not know why those UITextViews are not shown. Did I forget something? To show really everything, here are the connections that I made in InterfaceBuilder:
Does anyone know what I did wrong and can help me?
I think your initial code should be like this :
tasteView = [[TasteView alloc] init];
[[self view] addSubview:tasteView];
[self setCurrentView:tasteView];
addSubView after it is allocated
Hope it helps you
If you are creating the view in code (your first sample), alloc and init the view before trying to add it as a subview.
If you're loading it from another nib (last code section), you still need to add it to the view hierarchy.
Related
Where should I initialize a UITablewView as a subview, in - (id)initWithFrame:(CGRect)frame, in viewdidload or loadView? Which is the better approach? Where should I make the frame (I mean which is more effective)?
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self)
{
self.backgroundColor = kViewBackgroundColor;
_tableView = [[UITableView alloc] initWithFrame:CGRectZero style:UITableViewStyleGrouped];
_tableView.backgroundView = nil;
_tableView.backgroundColor = [UIColor clearColor];
_tableView.bounces = NO;
[self addSubview:_tableView];
}
return self;
}
On my projects I usually create a baseViewController with a custom initialiser like this:
- (id)init{
self = [self initWithNibName:NSStringFromClass([self class]) bundle:[NSBundle mainBundle]];
if (self) {
//You should create the tableView and other properties here
//and add as subviews inside viewDidLoad
_tableView = [[UITableView alloc]initWithFrame:CGRectMake(0,0,100,100)];
}
return self;
}
and I always create my view controller by using this init method, because I don't think the other vc's need to know the name of the nib file. If I were you I would create subviews inside init method, add as subviews inside viewDidLoad or viewWillAppear and finally releasing them inside dealloc if you are not using ARC.
Generally this depends on your requirement that if you are having custom view called with a tableview as subview then loadview with the initwithframe method will be better and while you want to initialize it from viewcontroller then viewdidload is better. I think you should bifurcate your requirement. Hope this helps.
Since you are initializing table view with zero frame it wont be visible even if you added that
you can try this
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self)
{
self.backgroundColor = kViewBackgroundColor;
UITableView *_tableView = [[UITableView alloc] initWithFrame:self.bounds style:UITableViewStyleGrouped];
_tableView.backgroundView = nil;
_tableView.backgroundColor = [UIColor clearColor];
_tableView.bounces = NO;
[_tableView setAutoresizingMask:UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleWidth]
[self addSubview:_tableView];
}
return self;
}
If you'd like to create subviews programmatically based on superview metrics (frame or bounds), you should do it in viewDidLoad, because if you do in in initializer, metrics of self.view will not be avaliable, and you subviews will be created with zero frame and will not be visible (as Johnykutty) mentioned above.
But that does not seem to be a good practice in case your subview initialization routines require heavy operations.
Offtopic: I've been codin' for a looong time trying to do everything programmatically, never using xibs, etc. Well, if you ask me now, xibs really save your time and make life easier. Consider using interface builder for layout\autolayout, colors\borders etc stuff.
I want to check if my view has already been added to the view, so that the user cannot repeatedly add the new UIViewController onto the view.
if (!self.fmovc)
{
self.fmovc = [[FMOVC alloc] initWithNibName: #"FMOVC" bundle:nil];
}
BOOL viewAlreadyDisplayed = NO;
for (UIView * b in self.view.subviews)
{
if ([b isKindOfClass:[FMOVC class]])
{
viewAlreadyDisplayed = YES;
}
}
if (!viewAlreadyDisplayed)
{
[self.view addSubview:self.fmovc.view];
}
This is not working because it never triggers
viewAlreadyDisplayed = YES;
What is the correct way to go about finding if your view is already being displayed?
Thanks,
-Code
Before adding just removeItFromSuperView...It may solve your prob
[self.fmovc.view removeFromSuperview];
[self.view addSubview:self.fmovc.view];
Make the UIView member variable say thatView;
if(!thatView) {
thatView = [[UIView alloc] init];
[self.view addSubView:thatView];
}
Once you release the superview, release thatView & make thatView to nil.
OR
always check & remove thatView if present from superview before allocating thatView.
Hope this Helps !!!
I have a UINavigationController/UITableView and I want to present a UIView over top of it when the table is empty to give the user a prompt on how to add items to the table.
I've never make a UIView (as opposed to a UIViewController before) so I'll step through what I did to make it:
Make a new UIView Class - MakeSentenceHelperView
Make a nib called MakeSentenceHelperView.xib
Set File's owner to MakeSentenceHelperView
Load the nib in the MakeSentenceHelperView:
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
NSLog(#"makesentencehelperview init");
[[NSBundle mainBundle] loadNibNamed:#"MakeSentenceHelperView" owner:self options:nil];
}
return self;
}
and present the MakeSentenceHelperView in the UITableViewController:
//present the placeholder view for sentences
MakeSentenceHelperView *makeSentenceHelperView = [[MakeSentenceHelperView alloc] init];
NSLog(#"present placeholder: self.navigationcontroller.view: %#", self.navigationController.view);
//Something like this:
[self.navigationController.view addSubview:makeSentenceHelperView];
[self.navigationController.view bringSubviewToFront:makeSentenceHelperView];
The class loads and logs ok, but nothing appears in front of the UITableView - where have I gone wrong?
UPDATE: if I add [self.tableView setHidden:YES]; then the tableview disappears and the space is black and empty. I'm assuming this means I'm setting up the View wrong, somewhere.
You can use https://github.com/ecstasy2/toast-notifications-ios/ for showing Toast view liek Android. Check array size and if table view is not showing then called this one and show any custom method.
Thanks to #Aadhira for their link which led me to the problem.
I needed to add awakeFromNib
I was missing [self addSubview:self.view]; at the end of initWithFrame.
I can't figure out what the problem is here. I have a very simple UIViewController with a very simple viewDidLoad method:
-(void)viewDidLoad {
NSLog(#"making game view");
GameView *v = [[GameView alloc] initWithFrame:CGRectMake(0,0,320,460)];
[self.view addSubview:v];
[super viewDidLoad];
}
And my GameView is initialized as follows:
#interface GameView : UIView {
and it simply has a new drawRect method:
- (void)drawRect:(CGRect)rect
{
[super drawRect:rect];
NSLog(#"drawing");
}
In my console, I see "making game view" being printed, but "drawing" never is printed. Why? Why isn't my drawRect method in my custom UIView being called. I'm literally just trying to draw a circle on the screen.
Have you tried specifying the frame in the initialization of the view? Because you are creating a custom UIView, you need to specify the frame for the view before the drawing method is called.
Try changing your viewDidLoad to the following:
NSLog(#"making game view");
GameView *v = [[GameView alloc] initWithFrame:CGRectMake(0,0,320,460)];
if (v == nil)
NSLog(#"was not allocated and/or initialized");
[self.view addSubview:v];
if (v.superview == nil)
NSLog(#"was not added to view");
[super viewDidLoad];
let me know what you get.
Check if your view is being displayed. If a view is not currently on screen, drawRect will not be getting called even if you add the view to its superview. A possibility is that your view is blocked by the some other view.
And as far as I know, you don't need to write [super drawRect];
Note that even if viewDidLoad is called on a view controller it doesn't necessarily indicate the view controller's view is displayed on screen. Example: Assume a view controller A has an ivar where a view controller B is stored and view controller A's view is currently displayed. Also assume B is alloced and inited. Now if some method in A causes B's view to be accessed viewDidLoad in B will be called as a result regardless whether it's displayed.
If you're using a CocoaTouch lib or file you may need to override the initWithCoder method instead of viewDidLoad.
Objective-C:
- (instancetype)initWithCoder:(NSCoder *)coder
{
self = [super initWithCoder:coder];
if (self) {
//Do Stuff Here
}
return self;
}
I had a view that was offscreen, that I would load onscreen and then redraw. However, while cleaning up auto-layout constraints in XCode, it decided my offscreen view should have a frame (0,0,0,0) (x,y,w,h). And with a (0,0) size, the view would never load.
Make sure your NSView has a nonzero frame size, or else drawRect will not be called.
Ok, here's another question.
I am creating a UIView called ProgressView that is a semi-transparent view with an activity indicator and a progress bar.
I want to be able to use this view throughout different view controllers in my app, when required.
I know of 3 different ways of doing this (but I am only interested in one):
1) Create the entire view programatically, instantiate and configure as required. No worries I get that one.
2) Create the UIView in interface builder, add the required objects and load it using a method like the below. Problem with this is that we are basically guessing that the view is the objectAtIndex:0 because nowhere in the documentation I found a reference to the order of the elements returned from the [[NSBundle mainBundle] loadNibName: function.
NSArray *nibContents = [[NSBundle mainBundle] loadNibNamed:#"yournib"
owner:self
options:nil];
UIView *myView = [nibContents objectAtIndex:0];
myView.frame = CGRectMake(0,0,300,400); //or whatever coordinates you need
[scrollview addSubview:myView];
3) Subclass UIViewController and let it manage the view as per normal. In this case I would never be actually pushing the view controller onto the stack, but only its main view:
ProgressViewController *vc = [[ProgressViewController alloc] initWithNibName:#"ProgressView" bundle:nil];
[vc.view setCenter:CGPointMake(self.view.center.x, self.view.center.y)];
[self.view addSubview:vc.view];
[vc release];
As far as I can tell, #3 is the the correct way of doing this (apart from programatically) but I am not entirely sure if it is safe to release the ProgressView's view controller whilst another controller's view is retaining its main view (gut feel says it is going to leak?)?
What do I do in terms of memory management in this case, where and when should I release the ProgressView's view controller?
Thanks in advance for your thoughts.
Cheers,
Rog
I think that your solution #3 adds unnecessary complexity by introducing a UIViewController instance just as a container for your ProgressView so that you can setup nib bindings. While I do think that it is nice to be able to work with an IBOutlet bound property rather than iterating through the nib contents you can do so without introducing a UIViewController whose behavior you neither need nor want. This should avoid your confusion around how and when to release the view controller and what, if any, side effects it might have on the responder chain or other behaviors of the loaded view.
Instead please reconsider using NSBundle and taking advantage of the power of that owner argument.
#interface ProgressViewContainer : NSObject {
}
#property (nonatomic, retain) IBOutlet ProgressView *progressView;
#end
#implementation ProgressViewContainer
#synthesize progressView = progressView;
- (void) dealloc {
[progressView release];
[super dealloc];
}
#end
#interface ProgressView : UIView {
}
+ (ProgressView *) newProgressView;
#end
#implementation ProgressView
+ (ProgressView *) newProgressView {
ProgressViewContainer *container = [[ProgressViewContainer alloc] init];
[[NSBundle mainBundle] loadNibNamed:#"ProgressView" owner:container options:nil];
ProgressView *progressView = [container.progressView retain];
[container release];
return progressView;
}
#end
Create a nib named "ProgressView" containing a ProgressView and set it's File's Owner class to ProgressViewContainer. Now you can create ProgressViews loaded from your nib.
ProgressView *progressView = [ProgressView newProgressView];
[scrollView addSubview:progressView];
[progressView release];
If you have multiple configurations of your progress view then maybe you'll want to implement a -initWithNibNamed: method on ProgressView instead of +newProgressView so you can specify which nib to use to create each ProgressView instance.
I vote for option #2. The return value from -[NSBundle loadNibNamed] is an array of the top-level objects. So as long as you have just one top level object in your nib, then the index 0 will be correct. The other views are subviews and not top level objects.
Another option of course is to do something like create a superclass for all of your view controllers that includes an outlet called something like 'progressView' and then connect your view to that outlet on file's owner in the nib. Seems like overkill for this, though.
I also prefer alternative #2. If the "0" is bothering you, you could:
Create a subclass of UIView called ProgressView
Create a nib-file called ProgressView.xib describing your progress view.
Select the topmost view in your nib, and set its Class to ProgressView in interface builder
then do
NSArray *nibContents = [[NSBundle mainBundle] loadNibNamed:#"ProgressView" owner:self options:nil];
ProgressView *progressView = nil;
for (UIView *view in nibContents) {
if ([view isKindOfClass:[ProgressView class]]) {
progressView = (ProgressView *) view;
break;
}
}
if (progressView != nil) {
//Use progressView here
}
I ended up adding a category to UIView for this:
#import "UIViewNibLoading.h"
#implementation UIView (UIViewNibLoading)
+ (id) loadNibNamed:(NSString *) nibName {
return [UIView loadNibNamed:nibName fromBundle:[NSBundle mainBundle] retainingObjectWithTag:1];
}
+ (id) loadNibNamed:(NSString *) nibName fromBundle:(NSBundle *) bundle retainingObjectWithTag:(NSUInteger) tag {
NSArray * nib = [bundle loadNibNamed:nibName owner:nil options:nil];
if(!nib) return nil;
UIView * target = nil;
for(UIView * view in nib) {
if(view.tag == tag) {
target = [view retain];
break;
}
}
if(target && [target respondsToSelector:#selector(viewDidLoad)]) {
[target performSelector:#selector(viewDidLoad)];
}
return [target autorelease];
}
#end
explanation here: http://gngrwzrd.com/blog-view-controller-less-view-loading-ios-mac.html