I am creating a modal view in an App, which contains several subviews. Each one of those subviews has a button and an action related to that button. I use a loop to insert each subview in place. The problem is that the first 4 subviews are ok, from the 5th to the last there are no responses.
Here it is the simplified code related to the problem:
Simplified SubviewView.m
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// More info button
CGRect buttonFrame = CGRectMake(infoMarginLeft + infoWidthWithInfo, infoHeightControl, 25, 25);
UIButton * button = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
[button setFrame:buttonFrame];
[button addTarget:self action:#selector(buttonTapped:) forControlEvents:UIControlEventTouchUpInside];
[self addSubview:button];
}
return self;
}
-(void)buttonTapped:(id)sender
{
NSLog(#"Button tapped!";
}
Simplified view.m
- (void)drawRect:(CGRect)rect
{
for (int i = 0; i < 12; i++) {
// Color info container
SubviewView * miniView = [[SubviewView alloc] initWithFrame:CGRectMake(0, 20 * i, 15, 15)];
miniColorView.backgroundColor = [UIColor clearColor];
// Adding subview through array to keep track of objects
[self addSubview:miniColorView];
}
}
Thanks in advance, I have absolutely no ideia of what's going on :p
--
EDIT
Just found out what it was!
The parent view had as height the screen height. The thing is, some of the subviews were beyond the screen height limit. All I had to do was increase the parent view height =)
I would check to make sure you are not adding your view miniView over top of your button.
Also this should be moved outside of drawRect, just put this in your init method.
Edit:
Set your miniView's background color to another besides clear, and see if you still see your button. If not, then you covered up your button, and it won't receive touch events.
Related
the user should be able to select one icon from a large number of different icons. I have created a picker dialog that allows the user to make his selection. The ViewController that is used for this picker only holds one UIScrollView. In viewDidLoad for each icon a button is added to the ScrollView. To select an icon the user just has to click the corresponding button...
This works fine, but the ViewController/picker needs several seconds to be displayed. This is because of the many alloc / add operations within viewDidLoad. Because of this I tried to move these options into a background thread. This workes fine, but the created buttons are not visible any more:
- (void)viewDidLoad {
[super viewDidLoad];
self.iconsScrollView.hidden = true;
[self.activityIndicator startAnimating];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
iconContainer = [[UIView alloc] init];
iconContainer.backgroundColor = [UIColor clearColor];
iconButtons = [[NSMutableDictionary alloc] init];
CGRect buttonRect = CGRectMake(5, 5, 40, 40);
selectedButton = nil;
NSArray *iconInfos = [[StoreController sharedController] allIcons];
for (IconInfo* iconInfo in iconInfos) {
NSString *iconName = iconInfo.name;
UIButton *iconButton = [UIButton buttonWithType:UIButtonTypeCustom];
iconButton.frame = buttonRect;
[iconButton addTarget:self action:#selector(iconSelectionClick:) forControlEvents: UIControlEventTouchUpInside];
[iconButton setImage:[UIImage imageNamed:iconName] forState:UIControlStateNormal];
[iconContainer addSubview:iconButton];
[iconButtons setObject:iconButton forKey:iconInfo.guid];
buttonRect.origin.x += 50;
if (buttonRect.origin.x > 205) {
buttonRect.origin.x = 5;
buttonRect.origin.y += 50;
}
}
iconContainer.frame = CGRectMake(0, 0, self.iconsScrollView.frame.size.width, ceil([iconButtons count] / 5.0) * 50);
dispatch_async(dispatch_get_main_queue(), ^{
[self.iconsScrollView addSubview:iconContainer];
self.iconsScrollView.contentSize = iconContainer.frame.size;
[self.activityIndicator stopAnimating];
self.iconsScrollView.hidden = false;
[self.view setNeedsDisplay];
});
});
}
This works (almost) without any problem:
Picker ViewController is presented
ActivityIndicator is visible while buttons are created
Once all buttons are ready ActivityIndicator stops and the ScrollView becomes visible.
Only Problem: The Buttons are not visible. The ScrollView can be used normally (content size correct) and when I touch inside the ScrollView and hit an invisible button the click selector is called. Thus all buttons are there but not visible. Eventually after 10-15 seconds all Buttons become visible at once.
Using setNeedsDisplay or setNeedsLayout for the View, the ScrollView, or the buttons does not change anything.
Any idea what I can do?
You are adding buttons to a subview while you aren't on the main thread.
Generally, UIKit code should only be run on the main queue.
UIKit can only be updated from the main thread
dispatch_async(dispatch_get_main_queue(), ^(void){
//Run UI Updates
});
I am creating an iOS app with a seating plan layout.
Trying to use an object-oriented approach, I created a class for TableLayoutObjects as they have different properties.
And to lay these TableLayoutObjects out on the screen I am representing them as UIButtons that are created as I loop through the array of TableLayoutObjects.
- (void) loadTables
{
for (TableLayoutObjects *layoutObjs in arrTableLayoutObjects)
{
if ([layoutObjs.shape isEqualToString:#"r"]) {
// rectangle
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
......
if(layoutObjs.isInteractable) {
[button addTarget:self action:#selector(tableTouchedDown:) forControlEvents:UIControlEventTouchDown];
[button addTarget:self action:#selector(tableTouchedUpInside:) forControlEvents:UIControlEventTouchUpInside];
}
} else {
// text only. use label
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(layoutObjs.posX, layoutObjs.posY, layoutObjs.width, layoutObjs.height)];
......
}
}
}
My event handlers look like the below for now.
// reverts back to original color and perform other instructions
- (void) tableTouchedUpInside:(UIButton *) button
{
button.layer.backgroundColor = [UIColor colorWithWhite:0.2f alpha:.5f].CGColor;
}
My question is: how do I identify the UIButtons to their TableLayoutObjects? In the event handler after I change the colour of the button, I will also want to get or set some properties of the selected TableLayoutObjects. How can I do that?
I think your example is a perfect fit for implementing a UICollectionView. Solution with the buttons is less clean and more complex.
You can set the tag of the button to the index into the arrTableLayoutObjects array of the associated item.
Alternatively, create a custom class which takes the table as a parameter and is the target of the button. This object now has direct access to the button and the table item.
I'm trying to build a simple UIScrollView with paging to horizontally scroll between 3 images.
The tricky part is that I would like that each image would be clickable and catch the click event.
My technique is to create 3 UIButtons that each consists UIImage. give each button a tag and set an action.
Problem: I can catch the click event - BUT it's not scrollable!
Here is my code:
- (void) viewDidAppear:(BOOL)animated {
_imageArray = [[NSArray alloc] initWithObjects:#"content_01.png", #"content_02.png", #"content_03.png", nil];
for (int i = 0; i < [_imageArray count]; i++) {
//We'll create an imageView object in every 'page' of our scrollView.
CGRect frame;
frame.origin.x = _contentScrollView.frame.size.width * i;
frame.origin.y = 0;
frame.size = _contentScrollView.frame.size;
//
//get the image to use, however you want
UIImage* image = [UIImage imageNamed:[_imageArray objectAtIndex:i]];
UIButton* button = [[UIButton alloc] initWithFrame:frame];
//set the button states you want the image to show up for
[button setImage:image forState:UIControlStateNormal];
[button setImage:image forState:UIControlStateHighlighted];
//create the touch event target, i am calling the 'productImagePressed' method
[button addTarget:self action:#selector(imagePressed:)
forControlEvents:UIControlEventTouchUpInside];
//i set the tag to the image #, i was looking though an array of them
button.tag = i;
[_contentScrollView addSubview:button];
}
//Set the content size of our scrollview according to the total width of our imageView objects.
_contentScrollView.contentSize = CGSizeMake(_contentScrollView.frame.size.width * [_imageArray count], _contentScrollView.frame.size.height);
_contentScrollView.backgroundColor = [ENGAppDelegate backgroundColor];
_contentScrollView.delegate = self;
}
Well, since UIButton is an UIControl subclass, it "eats up" the touches of your scroll view:
[UIScrollView touchesShouldCancelInContentView:] The default returned value is YES if view is not a UIControl object; otherwise, it returns NO.
(from https://developer.apple.com/library/ios/documentation/uikit/reference/UIScrollView_Class/Reference/UIScrollView.html#//apple_ref/occ/instm/UIScrollView/touchesShouldCancelInContentView:)
You could influence this by subclassing UIScrollView and overwriting touchesShouldCancelInContentView: (and/or touchesShouldBegin:withEvent:inContentView:). However, for your use case I'd not use buttons in the first place. Why not just add a tap gesture recognizer to the scrollview and use the touch point to determine which image has been tapped? That's much easier and should work without any issues.
This completely solved this issue for me:
scrollview.panGestureRecognizer.delaysTouchesBegan = YES;
Credit goes to https://stackoverflow.com/users/904365/kjuly for providing the right answer in this topic: ScrollView/TableView with UIControl/UIButton subviews not scrollable under iOS 8
In my app, I need to parse some data from the network, and add some customized buttons.
Later, when user click on it, I would provide more details.
An image view is the background for the app
The position of these buttons(xPos, yPos) are parsed from the server(dynamic data)
no prints when I click on these buttons that I add programmatically
The code I have for adding it is like this
...
[businessButton setImage:businessImage forState:UIControlStateNormal];
[businessButton setFrame:CGRectMake([xPos floatValue], [yPos floatValue], [businessImage size].width/2, [businessImage size].width/2)];
[businessButton addTarget:self.imageView action:#selector(serviceProviderSelected:) forControlEvents:UIControlEventTouchUpInside];
...
- (void)serviceProviderSelected:(id)sender
{
NSLog(#"sp tapped\n");
}
I created another dummy app to do (what I think is the same thing), and the button works out fine...
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
UIButton *customizedButton = [UIButton buttonWithType:UIButtonTypeCustom];
UIImage *image = [UIImage imageNamed:#"business-icon.png"];
[customizedButton setImage:image forState:UIControlStateNormal];
[customizedButton setFrame:CGRectMake(100, 100, 20, 20)];
[customizedButton addTarget:self action:#selector(customButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:customizedButton];
}
- (IBAction)buttonPressed:(id)sender {
NSLog(#"yes, pressed\n");
}
I've been suspecting that the buttons I create in code are already released, and printed out the array that I use for storing these Buttons, they are valid addresses though...
Thanks!
William
I just found out why.
Instead of [self.imageView addSubview:businessButton];, [self.view addSubview:businessButton]; works now.
I think I didn't really understand how the view relationship was after adding an imageView in storyboard.
UIImageView has user interactions disabled by default. you have to set this property to YES in order to get an UIButton or anything else working as it's subview
You need to do:
[businessButton addTarget:self action:#selector(serviceProviderSelected:) forControlEvents:UIControlEventTouchUpInside];
The target needs to be the class that defines the selector.
I have a method makeButtons (posted here), which is removing all buttons in the screen and adding them again. This works fine in viewDidLoad and viewDidAppear. I am accessing information from a webservice which is telling me I need a new button. When I am calling [self makebuttons] from that method, nothing happends, until I move forth and back with my NavigationController forcing viewDidAppear to do the work again. My question is why? I am doing exactly the same, unless it's not called from viewDidAppear, but from doneGettingInformation.
- (void) viewDidAppear:(bool) animated {
[self makebuttons]; // Works great!
}
- (void) doneGettingInformation : (ASIFormDataRequest *) request {
NSString *response = [request responseString];
[[self.temp.userInfo objectForKey:#"spillider"] addObject:response];
[self makebuttons]; // This gets called, but nothing changes in the view itself.
}
- (void) makeButtons {
NSLog(#"kjort");
int newAntall = [[self.temp.userInfo objectForKey:#"spillider"] count];
for (UIButton * button in gameButtons) {
NSString *tag = [NSString stringWithFormat:#"%i",button.tag];
[button removeFromSuperview];
if ([webviews objectForKey:tag]) {
[[webviews objectForKey:tag] removeFromSuperview];
[webviews removeObjectForKey:tag];
}
}
[gameButtons removeAllObjects];
scroller.contentSize = CGSizeMake(320, 480);
if (newAntall > 3) {
CGSize scrollContent = self.scroller.contentSize;
scrollContent.height = scrollContent.height+((newAntall-3)*BUTTON_HEIGTH);
self.scroller.contentSize = scrollContent;
}
int y = 163;
self.nyttSpillKnapp.frame = CGRectMake(BUTTON_X, y, BUTTON_WIDTH, 65);
for (int i=0; i<newAntall; i++) {
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setBackgroundImage:[UIImage imageNamed:#"knapp_midt"] forState:UIControlStateNormal];
[button setBackgroundImage:[UIImage imageNamed:#"knapp_midt"] forState:UIControlStateHighlighted];
[button setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
[button.titleLabel setFont:[UIFont systemFontOfSize:15]];
button.frame = CGRectMake(BUTTON_X, y, BUTTON_WIDTH, BUTTON_HEIGTH);
button.enabled = YES;
UISwipeGestureRecognizer *swipe = [[UISwipeGestureRecognizer alloc] initWithTarget:self
action:#selector(deleteButton:)];
swipe.direction = UISwipeGestureRecognizerDirectionRight;
[button addGestureRecognizer:swipe];
button.tag = [[[self.temp.userInfo objectForKey:#"spillider"] objectAtIndex:i] intValue];
NSString * tittel = [NSString stringWithFormat:#"spill %#",[[self.temp.userInfo objectForKey:#"spillider"] objectAtIndex:i]];
[button setTitle:tittel forState:UIControlStateNormal];
UIButton *subButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
subButton.transform = CGAffineTransformMakeRotation(M_PI_2);
subButton.tag = i;
CGRect subframe = CGRectMake(230, 5, subButton.frame.size.width, subButton.frame.size.height);
subButton.frame = subframe;
CGRect myframe = self.nyttSpillKnapp.frame;
myframe.origin.y = myframe.origin.y+BUTTON_HEIGTH;
self.nyttSpillKnapp.frame = myframe;
[subButton addTarget:self action:#selector(clickGameButton:) forControlEvents:UIControlEventTouchUpInside];
[button addSubview:subButton];
[gameButtons addObject:button];
[self.scroller addSubview:button];
y += BUTTON_HEIGTH;
}
}
To sum up, it only works if I am changing viewcontrollers back and forth causing viewWillAppear to get called. Why is that?
I am sorry for my messy methods.
Thanks
If you change the contents of the view outside of the initial view appearing process or layout changes, it's your responsibility to call setNeedsDisplay and inform the run loop that it needs to be redrawn.
The system will ask the view to draw it's contents initially or during layout changes which is why it works as part of the process to first show the view. During that initial process, the viewWill/DidAppear delegates will get called.
From the UIView class reference:
The View Drawing Cycle
View drawing occurs on an as-needed basis. When a view is first shown,
or when all or part of it becomes visible due to layout changes, the
system asks the view to draw its contents. For views that contain
custom content using UIKit or Core Graphics, the system calls the
view’s drawRect: method. Your implementation of this method is
responsible for drawing the view’s content into the current graphics
context, which is set up by the system automatically prior to calling
this method. This creates a static visual representation of your
view’s content that can then be displayed on the screen.
When the actual content of your view changes, it is your
responsibility to notify the system that your view needs to be
redrawn. You do this by calling your view’s setNeedsDisplay or
setNeedsDisplayInRect: method of the view. These methods let the
system know that it should update the view during the next drawing
cycle. Because it waits until the next drawing cycle to update the
view, you can call these methods on multiple views to update them at
the same time.
EDIT:
Also, make sure done getting images is not called on a background thread. You can't edit views on a background thread. If it is you can prepare all the data on a bg thread but then call makeButtons on on the main thread (performSelectorOnMainThread or use blocks.
See GCD, Threads, Program Flow and UI Updating