I have a static table view controller. Within some of the cells, I have text boxes. I would like to enable or disable all the text boxes in one go. I know I could do something like
self.nameTextField.Enabled = NO;
self.ageTextField.Enabled = NO;
self.hairColorTextField.Enabled = NO;
But there has to be something more elegant. Something like
for (UIControl* control in self.allChildControls) { // <-- I totally just made that up.
if ([control isKindOfClass:[UITextField class]]) {
control.Enabled = NO;
}
}
I don't think I am asking the right question...
You can use the subviews property od UIView. It contains all child UI elements.
#property(nonatomic, readonly, copy) NSArray *subviews
UIView Documentation
for (UIView *subview in self.view.subviews) {
//check by class or tag
}
If you have a static tableviewController, I am assuming you aren't allowing the user to add/delete cells. If this is the case, your question is simple. You just need to add an outlet to each of the UITextField objects and toggle it's userInteractionEnabled property to no.
self.myTextField.userInteractionEnabled = NO;
self.mySecondTextField.userInteractionEnabled = NO;
Hope this helps :)
I have two windows, my main window "window" and "help window" all inside my App Delegate. In my main window its view is subclassed and I want to draw a rect inside it. My help window has a rect also but it has an NSTracker on it. What I want to do is draw my rect in my window subclass with the x and y coordinates equal to my NSTracker position. The problem I am having is it crashes when I try to bring in the coordinates, any ideas of what I could be doing wrong? thanks
//My subclass of window is called CutoutView. This is all in draw rect
AppDelegate *controller = [[[NSApp delegate] window] contentView];
xValue = controller.mouseLoc.x;
yValue = controller.mouseLoc.y;
NSRectFillUsingOperation(NSMakeRect(xValue,yValue, 600, 400), NSCompositeClear);
[self update];
- (void)update
{
NSLog(#"test");
[self setNeedsDisplay:YES];
}
//My AppDelegate with the tracker helpView is a reference to the view of my second window "Help Window"
-(void)updateTrackingAreas
{
if(trackingArea != nil) {
[self.helpView removeTrackingArea:trackingArea];
[trackingArea release];
}
opts = (NSTrackingActiveAlways | NSTrackingMouseEnteredAndExited | NSTrackingMouseMoved);
trackingArea = [ [NSTrackingArea alloc] initWithRect:[self.helpView bounds]
options:opts
owner:self
userInfo:nil];
[self.helpView addTrackingArea:trackingArea];
}
-(void)mouseMoved:(NSEvent *)theEvent
{
mouseLoc = [NSEvent mouseLocation];
NSLog(#"mouseMoved: %f %f", mouseLoc.x, mouseLoc.y);
}
in my CutoutView am i getting the AppController wrong because it is in a different window "helpWindow"? or does it have to do with my int values?
There are many things wrong with your code and it's obvious that you are fundamentally misunderstanding some basic concepts.
Firstly, you state that this code is in your drawRect: method;
AppDelegate *controller = [[[NSApp delegate] window] contentView];
xValue = controller.mouseLoc.x;
yValue = controller.mouseLoc.y;
NSRectFillUsingOperation(NSMakeRect(xValue,yValue, 600, 400), NSCompositeClear);
[self update];
There are several immediate flaws apparent. Firstly, why are you declaring controller to be of type AppController* when the method you are calling (-contentView) returns an NSView?
Your AppController is not a view (at least it should not be!), so you should be declaring the object as such:
NSView* mainView = [[[NSApp delegate] window] contentView];
If you are indeed using a view as a controller then this is completely wrong. See below for my note about MVC.
You don't specify where the mouseLoc property is coming from. We need to see where this is declared, because that will affect whether or not there are problems with it.
Your drawing code calls [self update], which simply tells the view to redraw itself. This will result in an infinite loop because every time the view draws it is forced to redraw. You should never call setNeedsDisplay: from inside drawRect:.
Even after making these changes, this code is very badly structured and the design is broken.
As it stands, your code violates the Model-View-Controller pattern. A views should not have knowledge of other views. You need to restructure things so that your views display properties of your controller without needing knowledge of other views. That means that you must store the mouse location in your controller (or a model object) and use some method for the view to access that information, preferably a datasource protocol or similar. In my answer to this other question I give an example of how to do that.
You need to read the Cocoa Drawing Guide. You also need to learn more core Cocoa concepts as it is clear you are misunderstanding how Cocoa is supposed to work.
I have a UITableView and UINavigationController, and I'd like to distinguish between two clicks: 1) normal click that selects a row and 2) a click that happens ANYWHERE else on the screen (other than the buttons on the UINavigationController). I wrote this code:
singleTap = [[UITapGestureRecognizer alloc]
initWithTarget:self action:#selector(singleTapHandler:)];
singleTap.numberOfTapsRequired = 1;
The problem with this however is that it overrides the normal clicks that select a row.
I assume you're putting the tap recognizer on either the UIWindow itself, or the window's sole subview. You need to give the tap recognizer a delegate, and that delegate needs to implement gestureRecognizer:shouldReceiveTouch:.
In that method, you want to return NO if the touch is in a button or if the touch is in a table view cell, and YES otherwise. You need to walk up the view hierarchy, starting with the view that the touch landed in, looking for either of those classes.
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
for (UIView *view = touch.view; view; view = view.superview) {
if ([view isKindOfClass:[UIButton class]])
return NO;
if ([view isKindOfClass:[UITableViewCell class]])
return NO;
}
return YES;
}
here's the problem:
I'd like to move to using UIGestureRecognizer in my Apps.
For this reason I'd like to ditch TouchBegan/TouchEnded event's from my views.
However I don't understand how to manage when the touch began (user puts its finger on the screen) with UIGestureRecognizers.
The simplest one is UITapGestureRecognizer but the selector associated gets fired only when the TapGesture is completed (Well... it makes completely sense of course). But still the problem remains: how can I stop using touchesBegan and get that event anyway from UIGestureRecognizer?
Thanks!
Here is an example:
//Pan gesture
recognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(handlePan:)];
((UIPanGestureRecognizer *)recognizer).minimumNumberOfTouches = 3; //number of fingers
recognizer.delegate = self;
[self.view addGestureRecognizer:recognizer];
[recognizer release];
- (void)handlePan:(UIPanGestureRecognizer *)recognizer
{
if (recognizer.state == UIGestureRecognizerStateBegan)
{
//do something
} else if (recognizer.state == UIGestureRecognizerStateEnded)
{
//do something
}
}
Also implement UIGestureRecognizerDelegate in .h file. May be you need to do self.view.userInteractionEnabled = YES depending on the view you're using. e.g., if it's UIImageView, the you need to set userInteractionEnabled = YES, default is NO
For what you are tryin ti do you can't. The gesture recoginizers are for high level gestures so they behaive the same across all apps (think swipes, the timing required for a double tap, etc). For low level control and to do things that the recognizers can't you will still have to implement logic in touchesbegan, touchesEnded, etc.
Why not implement your own touchesBegan in a UIGestureRecognizer subclass -- intercept the message, extract the information you'd like, and then pass the message along to super's touchesBegan?
Is there a simple way of allowing interaction with a button in a UIView that lies under another UIView - where there are no actual objects from the top UIView on top of the button?
For instance, at the moment I have a UIView (A) with an object at the top and an object at the bottom of the screen and nothing in the middle. This sits on top of another UIView that has buttons in the middle (B). However, I cannot seem to interact with the buttons in the middle of B.
I can see the buttons in B - I've set the background of A to clearColor - but the buttons in B do not seem to receive touches despite the fact that there are no objects from A actually on top of those buttons.
EDIT - I still want to be able to interact with the objects in the top UIView
Surely there is a simple way of doing this?
You should create a UIView subclass for your top view and override the following method:
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event {
// UIView will be "transparent" for touch events if we return NO
return (point.y < MIDDLE_Y1 || point.y > MIDDLE_Y2);
}
You may also look at the hitTest:event: method.
While many of the answers here will work, I'm a little surprised to see that the most convenient, generic and foolproof answer hasn't been given here. #Ash came closest, except that there is something strange going on with returning the superview... don't do that.
This answer is taken from an answer I gave to a similar question, here.
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
UIView *hitView = [super hitTest:point withEvent:event];
if (hitView == self) return nil;
return hitView;
}
[super hitTest:point withEvent:event] will return the deepest view in that view's hierarchy that was touched. If hitView == self (i.e. if there is no subview under the touch point), return nil, specifying that this view should not receive the touch. The way the responder chain works means that the view hierarchy above this point will continue to be traversed until a view is found that will respond to the touch. Don't return the superview, as it is not up to this view whether its superview should accept touches or not!
This solution is:
convenient, because it requires no references to any other views/subviews/objects;
generic, because it applies to any view that acts purely as a container for touchable subviews, and the configuration of the subviews does not affect the way it works (as it does if you override pointInside:withEvent: to return a particular touchable area).
foolproof, there's not much code... and the concept isn't difficult to get your head around.
I use this often enough that I have abstracted it into a subclass to save pointless view subclasses for one override. As a bonus, add a property to make it configurable:
#interface ISView : UIView
#property(nonatomic, assign) BOOL onlyRespondToTouchesInSubviews;
#end
#implementation ISView
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
UIView *hitView = [super hitTest:point withEvent:event];
if (hitView == self && onlyRespondToTouchesInSubviews) return nil;
return hitView;
}
#end
Then go wild and use this view wherever you might use a plain UIView. Configuring it is as simple as setting onlyRespondToTouchesInSubviews to YES.
There are several ways you could handle this. My favorite is to override hitTest:withEvent: in a view that is a common superview (maybe indirectly) to the conflicting views (sounds like you call these A and B). For example, something like this (here A and B are UIView pointers, where B is the "hidden" one, that is normally ignored):
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
CGPoint pointInB = [B convertPoint:point fromView:self];
if ([B pointInside:pointInB withEvent:event])
return B;
return [super hitTest:point withEvent:event];
}
You could also modify the pointInside:withEvent: method as gyim suggested. This lets you achieve essentially the same result by effectively "poking a hole" in A, at least for touches.
Another approach is event forwarding, which means overriding touchesBegan:withEvent: and similar methods (like touchesMoved:withEvent: etc) to send some touches to a different object than where they first go. For example, in A, you could write something like this:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
if ([self shouldForwardTouches:touches]) {
[B touchesBegan:touches withEvent:event];
}
else {
// Do whatever A does with touches.
}
}
However, this will not always work the way you expect! The main thing is that built-in controls like UIButton will always ignore forwarded touches. Because of this, the first approach is more reliable.
There's a good blog post explaining all this in more detail, along with a small working xcode project to demo the ideas, available here:
http://bynomial.com/blog/?p=74
You have to set upperView.userInteractionEnabled = NO;, otherwise the upper view will intercept the touches.
The Interface Builder version of this is a checkbox at the bottom of the View Attributes panel called "User Interaction Enabled". Uncheck it and you should be good to go.
Custom implementation of pointInside:withEvent: indeed seemed like the way to go, but dealing with hard-coded coordinates seemed odd to me. So I ended up checking whether the CGPoint was inside the button CGRect using the CGRectContainsPoint() function:
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event {
return (CGRectContainsPoint(disclosureButton.frame, point));
}
Lately I wrote a class that will help me with just that. Using it as a custom class for a UIButton or UIView will pass touch events that were executed on a transparent pixel.
This solution is a somewhat better than the accepted answer because you can still click a UIButton that is under a semi transparent UIView while the non transparent part of the UIView will still respond to touch events.
As you can see in the GIF, the Giraffe button is a simple rectangle but touch events on transparent areas are passed on to the yellow UIButton underneath.
Link to class
I guess I'm a bit late to this party, but I'll add this possible solution:
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
UIView *hitView = [super hitTest:point withEvent:event];
if (hitView != self) return hitView;
return [self superview];
}
If you use this code to override a custom UIView's standard hitTest function, it will ignore ONLY the view itself. Any subviews of that view will return their hits normally, and any hits that would have gone to the view itself are passed up to its superview.
-Ash
Just riffing on the Accepted Answer and putting this here for my reference. The Accepted Answer works perfectly. You can extend it like this to allow your view's subviews to receive the touch, OR pass it on to any views behind us:
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event {
// If one of our subviews wants it, return YES
for (UIView *subview in self.subviews) {
CGPoint pointInSubview = [subview convertPoint:point fromView:self];
if ([subview pointInside:pointInSubview withEvent:event]) {
return YES;
}
}
// otherwise return NO, as if userInteractionEnabled were NO
return NO;
}
Note: You don't even have to do recursion on the subview tree, because each pointInside:withEvent: method will handle that for you.
This approach is quite clean and allows that transparent subviews are not reacting to touches as well. Just subclass UIView and add the following method to its implementation:
#implementation PassThroughUIView
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event {
for (UIView *v in self.subviews) {
CGPoint localPoint = [v convertPoint:point fromView:self];
if (v.alpha > 0.01 && ![v isHidden] && v.userInteractionEnabled && [v pointInside:localPoint withEvent:event])
return YES;
}
return NO;
}
#end
Setting userInteraction property disabled might help. Eg:
UIView * topView = [[TOPView alloc] initWithFrame:[self bounds]];
[self addSubview:topView];
[topView setUserInteractionEnabled:NO];
(Note: In the code above, 'self' refers to a view)
This way, you can only display on the topView, but won't get user inputs. All those user touches will through this view and the bottom view will respond for them. I'd use this topView for displaying transparent images, or animate them.
My solution here:
-(UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
CGPoint pointInView = [self.toolkitController.toolbar convertPoint:point fromView:self];
if ([self.toolkitController.toolbar pointInside:pointInView withEvent:event]) {
self.userInteractionEnabled = YES;
} else {
self.userInteractionEnabled = NO;
}
return [super hitTest:point withEvent:event];
}
Hope this helps
There's something you can do to intercept the touch in both views.
Top view:
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
// Do code in the top view
[bottomView touchesBegan:touches withEvent:event]; // And pass them on to bottomView
// You have to implement the code for touchesBegan, touchesEnded, touchesCancelled in top/bottom view.
}
But that's the idea.
Here is a Swift version:
override func pointInside(point: CGPoint, withEvent event: UIEvent?) -> Bool {
return !CGRectContainsPoint(buttonView.frame, point)
}
Swift 3
override func point(inside point: CGPoint, with event: UIEvent?) -> Bool {
for subview in subviews {
if subview.frame.contains(point) {
return true
}
}
return false
}
I have never built a complete user interface using the UI toolkit, so I don't have much experience with it. Here is what I think should work though.
Every UIView, and this the UIWindow, has a property subviews, which is an NSArray containing all the subviews.
The first subview you add to a view will receive index 0, and the next index 1 and so forth. You can also replace addSubview: with insertSubview: atIndex: or insertSubview:aboveSubview: and such methods that can determine the position of your subview in the hierarchy.
So check your code to see which view you add first to your UIWindow. That will be 0, the other will be 1.
Now, from one of your subviews, to reach another you would do the following:
UIView * theOtherView = [[[self superview] subviews] objectAtIndex: 0];
// or using the properties syntax
UIView * theOtherView = [self.superview.subviews objectAtIndex:0];
Let me know if that works for your case!
(below this marker is my previous answer):
If views need to communicate with each other, they should do so via a controller (that is, using the popular MVC model).
When you create a new view, you can make sure it registers itself with a controller.
So the technique is to make sure your views register with a controller (which can store them by name or whatever you prefer in a Dictionary or Array). Either you can have the controller send a message for you, or you can get a reference to the view and communicate with it directly.
If your view doesn't have a link back the controller (which may be the case) then you can make use of singletons and/or class methods to get a reference to your controller.
I think the right way is to use the view chain built into the view hierarchy.
For your subviews that are pushed onto the main view, do not use the generic UIView, but instead subclass UIView (or one of its variants like UIImageView) to make MYView : UIView (or whatever supertype you want, such as UIImageView). In the implementation for YourView, implement the touchesBegan method. This method will then get invoked when that view is touched. All you need to have in that implementation is an instance method:
- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event ;
{ // cannot handle this event. pass off to super
[self.superview touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event]; }
this touchesBegan is a responder api, so you dont need to declare it in your public or private interface; it's one of those magic api's you just have to know about. This self.superview will bubble up the request eventually to the viewController. In the viewController, then, implement this touchesBegan to handle the touch.
Note that the touches location (CGPoint) is automatically adjusted relative to the encompassing view for you as it is bounced up the view hierarchy chain.
Just want to post this, coz I had somewhat similar problem, spent substantial amount of time trying to implement answers here without any luck. What I ended up doing:
for(UIGestureRecognizer *recognizer in topView.gestureRecognizers)
{
recognizer.delegate=self;
[bottomView addGestureRecognizer:recognizer];
}
topView.abView.userInteractionEnabled=NO;
and implementing UIGestureRecognizerDelegate :
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
return YES;
}
Bottom view was a navigation controller with number of segues and I had sort of a door on top of it that could close with pan gesture. Whole thing was embedded in yet another VC. Worked like a charm. Hope this helps.
Swift 4 Implementation for HitTest based solution
let hitView = super.hitTest(point, with: event)
if hitView == self { return nil }
return hitView
Derived from Stuart's excellent, and mostly foolproof answer, and Segev's useful implementation, here is a Swift 4 package that you can drop into any project:
extension UIColor {
static func colorOfPoint(point:CGPoint, in view: UIView) -> UIColor {
var pixel: [CUnsignedChar] = [0, 0, 0, 0]
let colorSpace = CGColorSpaceCreateDeviceRGB()
let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.premultipliedLast.rawValue)
let context = CGContext(data: &pixel, width: 1, height: 1, bitsPerComponent: 8, bytesPerRow: 4, space: colorSpace, bitmapInfo: bitmapInfo.rawValue)
context!.translateBy(x: -point.x, y: -point.y)
view.layer.render(in: context!)
let red: CGFloat = CGFloat(pixel[0]) / 255.0
let green: CGFloat = CGFloat(pixel[1]) / 255.0
let blue: CGFloat = CGFloat(pixel[2]) / 255.0
let alpha: CGFloat = CGFloat(pixel[3]) / 255.0
let color = UIColor(red:red, green: green, blue:blue, alpha:alpha)
return color
}
}
And then with hitTest:
override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
guard UIColor.colorOfPoint(point: point, in: self).cgColor.alpha > 0 else { return nil }
return super.hitTest(point, with: event)
}