I would like to be able to paint on top of my subviews, or in other words: have an overlay that does not block the events. So far I discovered:
- any instructions in drawRect are painted below subviews,
- putting a transparent UIView on top blocks events.
Is there another trick I can try?
Use a transparent UIView on top, and in IB uncheck "User Interaction Enabled" for that view, then input events will go down to your controls beneath it.
Or, in code do:
UIView *overlayView = [[UIView alloc] init...];
overlayView.userInteractionEnabled = NO;
To solve this you want to forward the hitTest events. Add the code below to your project, add a UIImageView to your interface, set its Class to ClickThroughImageView and connect the "onTopOf" outlet to whatever UIView is below the image.
The ClickThroughImageView.h file:
#import <Foundation/Foundation.h>
#interface ClickThroughImageView : UIImageView
{
IBOutlet UIView *onTopOf;
}
#property (nonatomic, retain) UIView *onTopOf;
#end
The ClickThroughImageView.m file
#import "ClickThroughImageView.h"
#implementation ClickThroughImageView : UIImageView
#synthesize onTopOf;
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
return [onTopOf hitTest:point withEvent:event];
}
#end
Related
I want to make an Advertising banner in my app. A bit like iAd's.
I was going to make it by having a UIImage on the view then assigning the banner image. I would then add a touch gesture so the user could click it and go to another view in my app. I Know That I can do this on one view quite easily but I want this to be on most views in the app. Whats the best way for adding the banner to more than one view with out writing the same code more that once?
The below design shows the sort of banner im after.
Thanks
#import <UIKit/UIKit.h>
#class custom;
#protocol adDelegate
- (void)viewAd:(NSString *)adRate;
#end
#interface custom : UIView
#property (strong, nonatomic) UIImage *viewImage;
#property (assign) id <adDelegate> delegate;
#end
// Main class
#import "custom.h"
#implementation custom
#synthesize viewImage;
#synthesize delegate;
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
UIImageView *imageView = [[UIImageView alloc] initWithFrame:frame];
imageView.image = viewImage;
[self addSubview:imageView];
}
return self;
}
- (id)initWithCoder:(NSCoder *)aDecoder
{
if ((self = [super initWithCoder:aDecoder]))
{
}
return self;
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
[self.delegate viewAd:#"view"];
}
You can Create a UIView Class and call it BannerView for instance.
// in the bannerView.h
#import <UIKit/UIKit.h>
#interface BannerView : UIView{
UIImageView* bannerImage;
}
#property(nonatomic,retain) UIImageView* bannerImage;
#end
//in the bannerView.m
#import "BannerView.h"
#implementation BannerView
#synthesize bannerImage;
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
}
return self;
}
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
// Drawing code
bannerImage=[[UIImageView alloc]initWithImage:[UIImage imageNamed:#"banner-image.png"]];
bannerImage.frame=CGRectMake(0, 0, 320, 100);
[self addSubview:bannerImage];
// add a uibutton on top of the uiimageview and assign an action for it
// better than creating an action recogniser
UIButton* actionButton=[UIButton buttonWithType:UIButtonTypeCustom];
actionButton.frame=CGRectMake(0, 0, 320, 100);
[actionButton addTarget:self action:#selector(yourAction) forControlEvents:UIControlEventTouchUpInside];
[self addSubview:actionButton];
}
-(void) yourAction{
// do what ever here like going to an other uiviewController as you mentionned
}
#end
Now you can call this view from any View Controller this way
BannerView* banner=[[BannerView alloc] initWithFrame:CGRectMake(0, 300, 320, 100)];
[self.view addSubview:banner];
Try creating a parent class from UIView where you do all the display and handling of the banner using your UIImageView and gesture recognizers. Then whichever views need this functionality, derive them from this parent class, and override default handling in method so that you can customize the behavior in your child class.
A few suggestions:
First, why not just use a UIButton instead of a UIImage with a Gesture? All you're really doing is replicating button functionality after all...
Second, I'd probably tackle the overall problem by creating a class that includes the UIButton, like so:
#interface YourSuperViewController : UIViewController
#property (nonatomic, strong) IBOutlet UIButton *adButton;
- (IBAction)adTouched:(id)sender;
#end
In the viewDidLoad for this class, create the button, and add it to the view, and add your ad-specific logic to the adTouched action.
Then create the rest of the views in your app as an instance of YourSuperViewController. Like so:
#interface SomeOtherViewController : YourSuperViewController
Now the SomeOtherViewController will auto-magically have the ad button and respond to a touch on it properly. Done!
What everyone else has said is the best way. If you need custom functionality, subclassing is probably the way to go.
I just wanted to add one pedantic thing. Its important to remember that a UIImage is not a view. There has never been a UIImage on the screen, ever. A UIImage is a model object. It is just a collection of data. A UIImageView is a view object and as such, a UIImageView can display itself on the screen.
This might seem overly pedantic and nitpicky, but its important to have these things sorted out in our heads in order to effectively use MVC (model, view, controller)
I have a view and view.UserInteractionenabled = no and a button is added to the view. i need to click the button only . is it possible to enable interaction for button only.
A view cannot receive touches unless userInteractionEnabled is YES for the view and all of its superviews up to the UIWindow object.
You can make a subclass of UIView to contain the button, and make it ignore touches outside the button by overriding hitTest:withEvent:. Example:
#interface MyView : UIView
#property (nonatomic, strong) IBOutlet UIButton *button;
#end
#implementation MyView
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
UIView *subview = [super hitTest:point withEvent:event];
return subview == self.button ? subview : nil;
}
#end
Well, i have gone through some decent goggling before posting this question but was unsuccessful in finding the right answers.
I cant really explain my entire app scenario here as it is a bit complex to explain. So, let me make this question very very simple. How can i change the frame of the UIKeyBoard.i.e. I want the UIKeyBoard to rotate or translate 90 degrees upwards to support my view position.
Is there a way out for me?
You can't change the default keyboard. You can, however, create a custom UIView to be used as keyboard replacement by setting it as inputView on, for example, a UITextField.
While creating a custom keyboard takes a bit of time, it works well with older iOS versions (inputView on the UITextField is available in iOS 3.2 and later) and supports physical keyboards (the keyboard is hidden automatically if one is connected).
Here's some sample code to create a vertical keyboard:
Interface:
#import <UIKit/UIKit.h>
#interface CustomKeyboardView : UIView
#property (nonatomic, strong) UIView *innerInputView;
#property (nonatomic, strong) UIView *underlayingView;
- (id)initForUnderlayingView:(UIView*)underlayingView;
#end
Implementation:
#import "CustomKeyboardView.h"
#implementation CustomKeyboardView
#synthesize innerInputView=_innerInputView;
#synthesize underlayingView=_underlayingView;
- (id)initForUnderlayingView:(UIView*)underlayingView
{
// Init a CustomKeyboardView with the size of the underlying view
// You might want to set an autoresizingMask on the innerInputView.
self = [super initWithFrame:underlayingView.bounds];
if (self)
{
self.underlayingView = underlayingView;
// Create the UIView that will contain the actual keyboard
self.innerInputView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 100, underlayingView.bounds.size.height)];
// You would need to add your custom buttons to this view; for this example, it's just red
self.innerInputView.backgroundColor = [UIColor redColor];
[self addSubview:self.innerInputView];
}
return self;
}
-(id)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
// A hitTest is executed whenever the user touches this UIView or any of its subviews.
id hitTest = [super hitTest:point withEvent:event];
// Since we want to ignore any clicks on the "transparent" part (this view), we execute another hitTest on the underlying view.
if (hitTest == self)
{
return [self.underlayingView hitTest:point withEvent:nil];
}
return hitTest;
}
#end
Using the custom keyboard in some UIViewController:
- (void)viewDidLoad
{
[super viewDidLoad];
CustomKeyboardView *customKeyboard = [[CustomKeyboardView alloc] initForUnderlayingView:self.view];
textField.inputView = customKeyboard;
}
I'm thinking of a way to have a UIView render itself onto another UIView as well as the first one. So I have my main UIView with it's bounds, and the UIView also renders itself in some other UIView.
Is this possible ? Does it require extensive layer operations?
Don't know whats your real intention is, but this will draw the view twice, userinteraction etc. will not work on the second view. Also this solution does not take care of different frame sizes.
Header of the View you want to clone
#interface SrcView : UIView
#property(nonatomic, readonly, strong) UIView *cloneView;
#end
#interface CloneView : UIView
#property(nonatomic, weak) UIView *srcView;
- (id)initWithView:(UIView *)src;
#end
implementation of the View you want to clone
#import "SrcView.h"
#import "CloneView.h"
#implementation SrcView
#synthesize cloneView;
- (void)drawLayer:(CALayer *)layer inContext:(CGContextRef)ctx{
[cloneView setNeedsDisplay];
}
- (UIView *)cloneView {
if (!cloneView) {
cloneView = [[CloneView alloc] initWithView:self];
}
return cloneView;
}
#end
#implementation CloneView
#synthesize srcView;
- (id)initWithView:(UIView *)src {
self = [super initWithFrame:src.frame];
if (self) {
srcView = src;
}
return self;
}
- (void)drawRect:(CGRect)rect
{
[srcView.layer renderInContext:UIGraphicsGetCurrentContext()];
}
#end
now you can just call cloneView and add it somewhere you want.
This seems to be an oft asked question here on StackOverflow. For example:
iphone, ipad Duplicate UIView - Cloned View
Copying the drawn contents of one UIView to another
UIView duplicate
Duplicate, clone or copy UIView
But if it were me doing this, my first approach would be to get a handle to the UIView I want to copy, then recursively iterate all the subviews of it and then copy & add them as subviews to the UIView I want to copy the main UIView into.
I can't imagine there's too much layer operations going on with this, but you would likely need to figure out how to programmatically re-establish outlets and/or actions.
There is no easy way to clone a view and then to update two views by one line of code. Because their underlying CALayers are different. But for duplicating a UIView, here is a new method you can use: Use UIView's method:
- (UIView *)snapshotViewAfterScreenUpdates:(BOOL)afterUpdates
This is the fastest way to draw a view. Available in iOS 7.
Create another instance of the UIView you wish to "clone" and add it as a subview to another view. You don't really clone a UIView object, you simply create another instance of it.
I'm having trouble getting my SubViews properly initialized using Interface Builder. I have the following View hierarchy (UIWindow -> BlankCanvasView -> StalkerView). BlankCanvasView is a subclass of UIView and StalkerView is a IBOutlet of BlankCanvasView
#interface BlankCanvasView : UIView {
IBOutlet UIView *stalker;
}
#end
I've established a connection between the stalker outlet of BlankCanvasView and the subview. However, in my touchesBegin method of BlankCanvasView the stalker outlet is nil. See below for touchesBegin.
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
NSLog(#"Touch Begin detected!!!");
NSLog(#"Stalker instance %#", stalker);
[UIView beginAnimations:#"StalkerAnimation" context:nil];
UITouch *touch = [touches anyObject];
//stalker is nil here!!!
[stalker setCenter:[touch previousLocationInView:self]];
[UIView commitAnimations];
}
What am I missing? It looks like none of my demo apps are properly loading any subviews when I try and follow examples on iTunesU.
If you are creating your 'stalker' view in IB, it must be part of the view hierarchy (that is, added as a subview of another view), or it must be retained by your code in order for it to not be released after loading. If you use a retain property for your stalker variable, this will be taken care of for you, automatically:
#interface BlankCanvasView : UIView
{
UIView *stalker;
}
#property (nonatomic, retain) IBOutlet UIView *stalker;
#end
Make sure you #synthesize stalker; in your BlankCanvasView's implementation, and set the property to nil when you're deallocating your view:
#implementation BlankCanvasView
#synthesize stalker;
- (void)dealloc
{
self.stalker = nil;
[super dealloc];
}
#end