I'm trying to realize an app that requires to move an UIImageView, that is put behind a transparent grid. How can I make it?
This is the code:
[[self view] addSubview:myimage];
myimage.userInteractionEnabled = YES;
UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(handlePan:)];
[panGesture setDelegate:self];
[myimage addGestureRecognizer:panGesture];
[self.view addSubview:over];
The transparent layer is "over".
If it is not added to the view, my pan method works.
When I add it, nothing works. So, how can I move my image behind the transparent grid?
Thank you everybody.
make over not clickable by setting userInteraction to no
if that doesn't work for some reason, use a custom class for over and override pointInside to always return NO :D
You can add aUIImageView as transparent layer over your image, and as UIImageView have by default userInteractionDisabled don't change that.
It's because if overlay image have user interaction then that would not let that pass to background view but 'll consume touches. Hence to enable panning on back ground view you need to pass touches on that view. By some approach. One of those is what I told you.
Related
Hi i am new to iOS programming.
I need to create an photo library like iPhone native photo app. I have found a library MWPhotoBrowser
that provides nearly same UI for photo browsing and its perfect for my requirement. But now i have 2 problems
First is that i need to create a grid layout with thumbnails. Clicking on an thumbnail should display image in full screen with browsing functionality. I tried to dynamically adding UIImageViews in UIScrollView, but UIScrollView is not scrolling and images are going out of screen.
Second is i could not get any tap handler on UIImageView so that i can open an image in full screen.
Looking for some tips here, i am really stuck here.
You can give a shot to this library, it has both features which you are looking for.
https://github.com/gdavis/FGallery-iPhone
Hope it helps :)
For ScrollView scrolling issue you have to increase scrlViewMain.contentSize dynamically. Create a for loop and put bellow code at the end of loop.
scrlViewMain.contentSize = CGSizeMake(0, incermentAsPerYourNeed);
For the tapping issue you have to add TapGesture. Put bellow code when your ImageView creates.
imgView.tag = giveAsPerYourRecordsID;
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleImageTap:)];
tap.cancelsTouchesInView = YES;
tap.numberOfTapsRequired = 1;
tap.delegate = self;
[imgView addGestureRecognizer:tap];
[tap release];
And bellow your catch method for tapping.
- (void) handleImageTap:(UIGestureRecognizer *)gestureRecognizer {
UIImageView *tmpImgView = (UIImageView *)gestureRecognizer.view;
}
I have also developed similar functionality a few days ago for my project.
For tap issue you should use UIButton instead of UIImageView, it gives you tap action event. For Scrollview not scrolling, just make sure you update contentSize property of UIScrollView, otherwise it would not scroll according to your subviews.
How can i use image to Perform an Action instead of Using Button or adding an image to Button, just wanna click button and perform particular set of instructions.
(Thanks in Advance)
Use a UIGestureRecogniser.
// IF your image view is called myImage
UIImageView *myImage = ...;
// Add a tap gesture recogniser
UITapGestureRecogniser *g = [[UITapGestureRecogniser alloc] initWithTarget:self action:#selector(imagePressed:)];
[myImage addGestureRecogniser:g];
[g release];
When your image is tapped, this method will get called
- (void)imagePressed:(UIGestureRecogniser *)recogniser {
NSLog(#"%#", recogniser);
}
Why don't you want to use a UIButton - it inherits from UIControl and has a lot of code that you probably don't even know exists? And it can just contain an image so it would look exactly the same?
Well, the pro about using UIButtons is that it got all touch events built right in. You can use UIImageViews, but you'll need to subclass them, while in most situations, a UIButton using a background-image would just fit.
In my app I have a UIView derived class Canvas that uses touchesBegan: withEvent:, touchesMoved: withEvent:, and touchesEnded: withEvent: to draw in the canvas. I also want to use a swipe to load the previous (or next) canvas in an array. I tried setting up the following gesture (and a similar one for right):
UISwipeGestureRecognizer* leftSwipe = [[UISwipeGestureRecognizer alloc] initWithTarget: self action: #selector(pageFlipNext)];
leftSwipe.direction = UISwipeGestureRecognizerDirectionLeft;
leftSwipe.numberOfTouchesRequired = 2;
[_canvas addGestureRecognizer: leftSwipe];
[leftSwipe release];
But my two fingered swipes are still being treated as one-fingered drawing instructions.
How do I get my app to handle the two-fingered swipe correctly?
First of all, I would get started verifying whether _canvas.multipleTouchEnabled is set to YES. If it isn't, set it to YES.
You might also want to consider
leftSwipe.delaysTouchesBegan = YES;
This will delay the touches to be sent to the _canvas until the gesture fails. You can also use a UIPanGestureRecognizer and do something like this,
[pan requireGestureRecognizerToFail:leftSwipe];
I think that you can use UIPanGestureRecognizer
UIPanGestureRecognizer is a concrete
subclass of UIGestureRecognizer that
looks for panning (dragging) gestures.
The user must be pressing one or more
fingers on a view while they pan it.
I have a UIView as a XIB in Portrait mode.
This view is added programmatically to the viewcontroller like this:
NSArray *nibObjects = [[NSBundle mainBundle] loadNibNamed:#"InputView" owner:self options:nil];
InputView *inputView = (InputView*)[nibObjects objectAtIndex:0];
[self.view addSubview:inputView];
This view has autoresizing masks set up properly and rotates fine when the orientation changes from Portrait to landscape.
However, if the orientation is already landscape and I create the view after the orientation change, it has its initial portrait orientation.
Is there a way to tell the view to initialize or resize itself to portrait by using its masks?
Thanks in advance for any reply!
EDIT:
Using the suggestions of occulus and Inder Kumar Rathore (thanks guys!), I altered the code to this:
InputView *inputView = (InputView*)[nibObjects objectAtIndex:0];
[self.view addSubview:inputView];
[self.view setNeedsLayout];
[self.view layoutSubviews];
[self.view layoutIfNeeded];
UIDeviceOrientation orientation = [[UIDevice currentDevice] orientation];
[self shouldAutorotateToInterfaceOrientation:orientation];
Unfortunately, there is no change at all.
I think I found someone asking the same question:
When adding a sub view the view does not resize if the app is in landscape mode
The answer identifies the problem correctly, but is not very encouraging...
Sure, I could create two nibs or resize the frame, but this seems so contrary to the idea of auto-resizing.
I find it hard to believe that there is no way to tell a nib after awakening and adding it to a view to use its autoresize features...something that works flawless when the device rotates.
EDIT 2:
The solution of idz works:
InputView *inputView = (InputView*)[nibObjects objectAtIndex:0];
[self.view addSubview:inputView];
inputView.frame = self.view.bounds;
[inputView show];
Thanks!
Often a NIB/XIB file contains a UIViewController that takes care of all of this. In this case, since their is no view controller (in the NIB/XIB) you need to take over its post-load duties.
Calling layoutSubviews directly, or indirectly via setNeedsLayout or layoutIfNeeded won't do you much good because the default implementation does nothing.
Assuming you want input view to fill the bounds of self.view you do the following:
InputView *inputView = (InputView*)[nibObjects objectAtIndex:0];
[self.view addSubview:inputView];
inputView.frame = self.view.bounds;
[inputView show];
All the resize masks of the sub-views must be correctly set for this to work and, obviously, if you don't want to fill the full bounds you may want to adjust the frame.
[self.view addSubview:viewSpinner];
viewSpinner.frame = self.view.frame;
[viewSpinner setNeedsLayout];
This works for me (Y)
I don't know if you still have this issue.
Let's say you have the following architecture:
window
subviewcontroller
(you implemented shouldautorotate correct to answering the wanted orientations)
Into this subviewcontroller you want to add the views of new UIViewControllers by just calling the addSubview function.
Instead of implementing the bounds manipulation in shouldautorotate, you should implement it in
- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation{
self.newUIViewController.view.frame = self.view.bounds;
}
didRotateFromInterface... is called after shouldRotate. In this function the bounds are already setup correctly.
This way you don't need so much manipulation by code.
See this related question:
When do autoresizing masks take effect in iOS?
So after loading your new view from the nib, and adding as a subview to self.view, try calling setNeedsLayout.
Using this method to hide the status bar:
[[UIApplication sharedApplication] setStatusBarHidden:YES animated:YES];
When setting "hidden" back to NO, the tap-to-scroll-to-top (in UIWebView, UITableView, whatever) doesn't work any more, and requires a restart of the app to get the functionality back.
Is this a bug (I filed a rdar anyhow) or have I missed a step? Should I perhaps expect this behavior since the statusBar "loses touch" somehow with the respective view?
You could try setting the ScrollsToTop property to true again after re-showing it:
[currentView setScrollsToTop:YES];
If that's not working, are you definitely only showing one view? If there is more than one scrolling view a scrollViewDidScrollToTop message is ignored...
In iOS 5.0 you can access the scrollview property of the UIWebView
webView.scrollView.scrollsToTop = YES;
The following fix by Alex worked for me. Thanks!
((UIScrollView *)[[webView subviews] objectAtIndex:0]).scrollsToTop = NO;
Being in a hurry this fix worked great, however given more time I might've subclassed the UIWebView and accessed the protected UIScrollView member directly.
The worry I have with Alex' method is that it assumes that UIScrollView is at index zero of the subviews (encapsulation allows private members to change). Which suggests another solution still:
for (UIView* v in [webView subviews])
{
if ([v isKindOfClass:[UIScrollView class]])
{
(UIScrollView *)v.scrollsToTop = NO;
}
}
I was having a similar problem where the scroll-to-top functionality was lost. Turns out this will only work when you have only one active view at a time (within the same scroll view). In my case I had a table view and another view which would fade in/out. Adding a removeFromSuperview at the end of the animation did the trick.
The answer was in the UIScrollView.h file comments:
/*
this is for the scroll to top gesture. by default, a single scroll visible scroll view with this flag set will get the call. if there is more than one visible with this
flag set or the delegeat method returns NO, the view isn't scrolled
*/
#property(nonatomic) BOOL scrollsToTop; // default is YES. if set, special gesture will scroll to top of view after consulting delegate
You can use the following code to have the UIWebView ignore scrollToTop without the extra UIScrollView:
((UIScrollView *)[[webView valueForKey:#"_internal"] valueForKey:#"scroller"]).scrollsToTop = NO;
I had a similar problem after playing a Youtube video within my app. scrollsToTop was still set to YES but tapping the status bar had no effect.
I finally realised that my app window was no longer the key window. After adding the following line to a UIWindow subclass (which I already had for other reasons) everything worked as it should again:
if (![self isKeyWindow]) [self makeKeyWindow];
I just ran across a similar behavior in the app I'm currently working on. In its case, if you load a YouTube video from within a UIWebView, scroll to top stops working for the rest of the application's life cycle. I kind of assume this might happen after loading the movie player as well, but haven't confirmed. That functionality has been around a lot longer and probably has fewer bugs.
When there are multiple scrollview, you can also set scrollUpToTop to NO for the others scrollview. cf:
setScrollsToTop with multiple UIScrollView classes and/or subclasses(UITableView)
I want to add my case, I add an UIWebView on an UIScrollView, as h4xxr had answered on the top:
If there is more than one scrolling view a scrollViewDidScrollToTop message is ignored
So, I get a simply way to make it work on webView: just set the scrollView·s scrollsToTop property false.
And when tap the status bar, it won`t got intercepted by the scrollView, and the webView scrolls to the top!
UIScrollView *scrollView = [[UIScrollView alloc] init];
scrollView.frame = self.view.bounds;
scrollView.scrollsToTop = false; //igore scrollView`s scrollsToTop
[self.view addSubview:scrollView];
UIWebView *webView = [[UIWebView alloc] init];
webView.frame = scrollView.bounds;
[scrollView addSubview:webView];