iPhone ScrollView and Picker Issue - iphone

I noticed an strange issue with my application that only occurs on the iPhone 3G and iPhone 3GS. I am creating a scroll view with two pages. On the second page of the scroll, when you try to scroll the picker, it is very unresponsive. It kinda appears that my application can't distinguish between the scrolling of the picker and the scrolling of the scrollview, because sometimes you scroll up and it goes to the left.
Please keep in mind, this works great on the iPhone 4 and iPhone 4S.
Has anyone ran into this problem before or any idea of what is actually going on?

Apparently the UIScrollView and UIPickerView cause problems if used together. However, this only occurred on the iPhone 3 and iPhone 3GS.
The solution was to subclass UIScrollView and implement the following method.
- (UIView *)hitTest:(CGPoint)point
withEvent:(UIEvent *)event
{
UIView *result = [super hitTest:point withEvent:event];
if ([result.superview isKindOfClass:[UIPickerView class]]) {
self.canCancelContentTouches = NO;
self.delaysContentTouches = NO;
}
else {
self.canCancelContentTouches = YES;
self.delaysContentTouches = YES;
}
return result;
}

You should only enable armv7 in your build settings (not armv6), that's all

Add a UIView over scroll view, over UIView add UIPickerView.

Related

UITableView scrolling problems when inside a UIScrollView

I have a UIScrollView (with paging) to which I add three UIViews. Each of these UIViews has a UITableView inside. So, the user should be able to scroll horizontally to the page he wants and then scroll vertically in the corresponding table.
However, some of the tables don't receive the scrolling gestures. Usually the first one does behave good, but the other ones do not. I can't select cells nor scroll the table up or down.
I used the default settings for the UIScrollView, except for these ones defined in the viewDidLoad:
- (void)viewDidLoad
{
[super viewDidLoad];
//Load the view controllers
[self loadViewControllers];
//Configure the scroll view
self.scrollView.pagingEnabled = YES;
self.scrollView.contentSize = CGSizeMake(CGRectGetWidth(self.scrollView.frame) * viewControllers.count, CGRectGetHeight(self.scrollView.frame));
self.scrollView.showsHorizontalScrollIndicator = NO;
self.scrollView.showsVerticalScrollIndicator = NO;
self.scrollView.scrollsToTop = NO;
self.scrollView.delegate = self;
//Configure the page control
self.pageControl.numberOfPages = viewControllers.count;
self.pageControl.currentPage = 0;
}
I can't figure out why I can't scroll some of the tables... Any help would be greatly appreciated.
Thanks in advance!
Try to set
self.scrollView.delaysContentTouches = YES;
self.scrollView.canCancelContentTouches = NO;
Maybe the UIScrollView don't pass touch informations to the subviews.
I tried to reproduce a simplified version of your needs using basically Interface Builder and it seems to me it's working using basic coding and using default settings. Can you pls check my quick n dirty Github repo and kindly ask to reply whether it is applicable to your situation or what is missing.
https://github.com/codedad/SO_ScrollView_with_Tables
By default Interface Builder creates UIScrollView and UITableViews enabling:
Delays Content Touches ON
Cancellable Content Touches ON
Things I would check:
Check your View Hierarchies - Is something being laid on top of your UITableView, causing it not to receive a tap?
Are your UITableViews being disabled anywhere? I would set a breakpoint in tableView:didSelectRowAtIndexPath: and see if that method is being called.
Check this post
I guess those aren't sure-fire answers but hopefully they'll help discover the problem!
This worked for me
I programmatically added the tableView to my scroll view using addSubview:
UIGestureRecognizerDelegate is needed.
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
if ([touch.view isDescendantOfView:self.signUpJammerList]) {
return NO;
}
return YES;
}

How do I remove the iPhone KeyBoard toolbar border?

I am using the following code to remove the toolbar from the iPhone keyboard when it is displayed.
- (void) keyboardDidShowNotification:(NSNotification *)aNotification {
NSArray *array = [[UIApplication sharedApplication] windows];
for (UIWindow* wind in array) {
for (UIView* currView in wind.subviews) {
if ([[currView description] hasPrefix:#"<UIPeripheralHostView"]) {
for (UIView* perView in currView.subviews) {
if ([[perView description] hasPrefix:#"<UIWebFormAccessory"]) {
[perView removeFromSuperview];
}
}
}
}
}
}
This is removing the toolbar like I want but it is still leaving a 1px border above where the toolbar use to be. How do I remove that as well?
Also this only appears to be an issue on iPhone Retina displays. iPhone 3GS and iPad Retina do not have it.
Seems to be a bug in removeFromSuperView. I had the same problem when adding a toolbar as an input accessory view to some pickers for inline editing. Calling 2x removeFromSuperView left the border.
Using [self.view endEditing:YES] when closing the picker helped to clean up the picker and the accessory view attached to it, with no border. Perhaps this can point you into the right direction?

removeFromSuperView fine on iPod but crashes on iPhone

While changing between different views in an iPhone application I'm developing, I add and remove subviews from a larger view. I have written code which works on the iPod 4, iPhone 3, iPad 1, iPad 2, as well as the simulators. However, I get a bad access error on the iPhone 4 with the removeFromSuperView call. I know that its probably because I over released something so the superview no longer exists, but how is it that it worked on all the other devices?
// Try to do like following -
if(subview.superview!=nil)
[subview removeFromSuperview];
//--------------------------------------------------------------
// If you have more view's then check view like this -
for(UIView * subview in self.view) {
if(subview == view1) {
if(subview.superview!=nil)
[subview removeFromSuperview];
}
else if(subview == view2){
if(subview.superview!=nil)
[subview removeFromSuperview];
}
.
.
.
}

UIDatePicker inside of a UIScrollView - iPhone application

How can I use a UIDatePicker inside of a UIScrollView in my iPhone app. I can't scroll through the dates on the picker, because it thinks my finger is controlling the UIScrollView instead. I'm trying to add a UIDatePicker to my UIScrollView, which is inside of my UIViewController.
You might try setting the scroll view's delaysContentTouches property to NO.
Better, though, would be to rethink your UI. A date picker takes up about half the screen on a small device. Even if you can get the date picker to scroll instead of the scroll view, you'll put the user in a position where it's going to be hard to scroll the scroll view. They'll have to figure out that they'll need to touch above or below the picker if they want to scroll the scroll view... it's just not going to be nice to use.
One solution might be to let the user tap a date, and then to present a modal view controller with a date picker. That'd let the user pick a new date without any ambiguity about scrolling.
After a few trials, I found the best solution to this problem was to subclass the scroll view that contains your date picker and do a hit test to see whether the user is trying to touch the picker. I found and adapted the code below from this question UIDatePicker inside UIScrollView with pages
- (UIView*)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
UIView* result = [super hitTest:point withEvent:event];
if ([result.superview isKindOfClass:[UIPickerView class]] || [result.superview isKindOfClass:[UIDatePicker class]])
{
self.canCancelContentTouches = NO;
self.delaysContentTouches = NO;
}
else
{
self.canCancelContentTouches = YES; // (or restore bool from prev value if needed)
self.delaysContentTouches = YES; // (same as above)
}
return result;
}
another solution is pop it upward from bottom when you want to select data from picker. add to ur view (self.view).

How to disable touch input to all views except the top-most view?

I have a view with multiple subviews. When a user taps a subview, the subview expands in size to cover most of the screen, but some of the other subviews are still visible underneath.
I want my app to ignore touches on the other subviews when one of the subviews is "expanded" like this. Is there a simple way to achieve this? I can write code to handle this, but I was hoping there's a simpler built-in way.
Hope this help...
[[yourSuperView subviews]
makeObjectsPerformSelector:#selector(setUserInteractionEnabled:)
withObject:[NSNumber numberWithBool:FALSE]];
which will disable userInteraction of a view's immediate subviews..Then give userInteraction to the only view you wanted
yourTouchableView.setUserInteraction = TRUE;
EDIT:
It seems in iOS disabling userInteraction on a parent view doesn't disable userInteraction on its childs.. So the code above (I mean the one with makeObjectsPerformSelector:)will only work to disable userInteraction of a parent's immediate subviews..
See user madewulf's answer which recursively get all subviews and disable user interaction of all of them. Or if you need to disable userInteraction of this view in many places in the project, You can categorize UIView to add that feature.. Something like this will do..
#interface UIView (UserInteractionFeatures)
-(void)setRecursiveUserInteraction:(BOOL)value;
#end
#implementation UIView(UserInteractionFeatures)
-(void)setRecursiveUserInteraction:(BOOL)value{
self.userInteractionEnabled = value;
for (UIView *view in [self subviews]) {
[view setRecursiveUserInteraction:value];
}
}
#end
Now you can call
[yourSuperView setRecursiveUserInteraction:NO];
Also user #lxt's suggestion of adding an invisible view on top of all view's is one other way of doing it..
There are a couple of ways of doing this. You could iterate through all your other subviews and set userInteractionEnabled = NO, but this is less than ideal if you have lots of other views (you would, after all, have to subsequently renable them all).
The way I do this is to create an invisible UIView that's the size of the entire screen that 'blocks' all the touches from going to the other views. Sometimes this is literally invisible, other times I may set it to black with an alpha value of 0.3 or so.
When you expand your main subview to fill the screen you can add this 'blocking' UIView behind it (using insertSubview: belowSubview:). When you minimize your expanded subview you can remove the invisible UIView from your hierarchy.
So not quite built-in, but I think the simplest approach. Not sure if that was what you were thinking of already, hopefully it was of some help.
Beware of the code given as solution here by Krishnabhadra:
[[yourSuperView subviews]makeObjectsPerformSelector:#selector(setUserInteractionEnabled:) withObject:[NSNumber numberWithBool:FALSE]];
This will not work in all cases because [yourSuperView subviews] only gives the direct subviews of the superview. To make it work, you will have to iterate recursively on all subviews:
-(void) disableRecursivelyAllSubviews:(UIView *) theView
{
theView.userInteractionEnabled = NO;
for(UIView* subview in [theView subviews])
{
[self disableRecursivelyAllSubviews:subview];
}
}
-(void) disableAllSubviewsOf:(UIView *) theView
{
for(UIView* subview in [theView subviews])
{
[self disableRecursivelyAllSubviews:subview];
}
}
Now a call to disableAllSubviewsOf will do what you wanted to do.
If you have a deep stack of views, the solution by lxt is probably better.
I would do this by putting a custom transparent button with the same frame as the superView. And then on top of that button I would put view that should accept user touches.
Button will swallow all touches and views behind it wouldn't receive any touch events, but view on top of the button will receive touches normally.
Something like this:
- (void)disableTouchesOnView:(UIView *)view {
UIButton *ghostButton = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, view.frame.size.width, view.frame.size.height)];
[ghostButton setBackgroundColor:[UIColor clearColor]];
ghostButton.tag = 42; // Any random number. Use #define to avoid putting numbers in code.
[view addSubview:ghostButton];
}
And a method for enabling the parentView.
- (void)enableTouchesOnView:(UIView *)view {
[[view viewWithTag:42] removeFromSuperview];
}
So, to disable all views in the parentViev behind yourView, I would do this:
YourView *yourView = [[YourView alloc] initWithCustomInitializer];
// It is important to disable touches on the parent view before adding the top most view.
[self disableTouchesOnView:parentView];
[parentView addSubview:yourView];
Just parentView.UserInteractionEnabled = NO will do the work.
Parent view will disable user interaction on all the view's subviews. But enable it does not enable all subviews(by default UIImageView is not interactable). So an easy way is find the parent view and use the code above, and there is no need to iterate all subviews to perform a selector.
Add a TapGestureRecognizer to your "background view" (the translucent one which "grays out" your normal interface) and set it to "Cancels Touches In View", without adding an action.
let captureTaps = UITapGestureRecognizer()
captureTaps.cancelsTouchesInView = true
dimmedOverlay?.addGestureRecognizer(captureTaps)
I will give my 2 cents to this problem.
Iteratively run userInteractionEnabled = false it's one way.
Another way will be add a UIView like following.
EZEventEater.h
#import <UIKit/UIKit.h>
#interface EZEventEater : UIView
#end
EZEventEater.m
#import "EZEventEater.h"
#implementation EZEventEater
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
self.backgroundColor = [UIColor clearColor];
self.userInteractionEnabled = false;
}
return self;
}
- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
//EZDEBUG(#"eater touched");
}
- (void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
}
- (void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
}
In your code you add the EZEventEater view to cover all the views that your may block the touch event.
Whenever you want to block the touch event to those views, simply call
eater.userInteractionEnabled = YES;
Hope this helpful.
In Swift 5, I achieved this behaviour by placing a view right on top(the highlighted one) and setting:
myView.isUserInteractionEnabled = true
This does not let the touches go through it, thus ignoring the taps.
For my app, I think it will be sufficient to disable navigation to other tabs of the app (for a limited duration, while I'm doing some processing):
self.tabBarController.view.userInteractionEnabled = NO;
Also, I disabled the current view controller--
self.view.userInteractionEnabled = NO;
(And, by the way, the recursive solutions proposed here had odd effects in my app. The disable seems to work fine, but the re-enable has odd effects-- some of the UI was not renabled).
Simple solution. Add a dummy gesture that does nothing. Make it reusable by adding it to an extension like this:
extension UIView {
func addNullGesture() {
let gesture = UITapGestureRecognizer(target: self,
action: #selector(nullGesture))
addGestureRecognizer(gesture)
}
#objc private func nullGesture() {}
}
setUserInteractionEnabled = NO on the view you want to disable
I had the same problem, but the above solutions did not help.
I then noticed that calling
super.touchesBegan(...) was the problem.
After removing this the event was only handled by the top-most view.
I hope this is of help to anybody.