Is there a way to change the "layer" that UIImageView objects are drawn in? Whenever I add an image view to a view controller it defaults to drawing the most recently added one on top of all the others. So if I decide to add a "background" image it is now a "foreground" image and blocks everything else.
There isn't anything in the IB options or in the UIImageView class reference and I haven't been able to find anything here on SO. It's been a problem for a while and it's weird that I haven't seen anything about it before... I think it might just be my semantics coming from a delphi background.
Anyway, does anyone know about this issue / ICANHAZTEHCODEZ to fix it? Or is this just like the UIScrollView problem and poorly supported by the development environment.
This happens when I try to use the editor to arrange the subviews.
You can bring a SubView to Front or Send it background programmatically using
[self.view bringSubviewToFront:yourImageView];
and
[self.view sendSubviewToBack:yourImageView];
when self.view must be the superview of your imageView
In IB, select a UIControl and from top menu bar select Editor->arrage->send to front or back
When you use UIView's addSubview: method, it will add it to the top of the view stack resulting in what you are seeing.
There are numerous other UIView methods you can use to determine the order of subviews. E.g.:
- (void)insertSubview:(UIView *)view aboveSubview:(UIView *)siblingSubview;
- (void)insertSubview:(UIView *)view atIndex:(NSInteger)index;
- (void)sendSubviewToBack:(UIView *)view;
- (void)bringSubviewToFront:(UIView *)view;
Related
I'm having this weird problem with size classes.
I noticed that any UIView which isn't installed in Any-Any size class is not part of the subviews when viewDidLoad is called.
Meaning I don't have access to it via my outlet nor does it appear in the [self.view subviews] array.
The subviews are placed fine on screen, and the first time I get to access them is in viewDidAppear.
I'm developing my app only for portrait iPhones so I set my Storyboard for compact width and regular height.
Am I doing something wrong? Do I need my storyboard to support Any-Any even though I don't really use this configuration?
AutoLayout hasn't completed until after the final viewDidLayoutSubviews call just before viewDidAppear.
- (void)viewDidLayoutSubviews
{
[super viewDidLayoutSubviews];
//Do your job with views or with its constraints...
}
You need your storyboard to support Any-Any even though you don't really use this configuration.
You have to enable Size Classes in Interface Builder, to do that please refer the following link.
https://developer.apple.com/library/ios/recipes/xcode_help-IB_adaptive_sizes/chapters/EnablingAdaptiveSizeDesign.html#//apple_ref/doc/uid/TP40014436-CH1-SW1
I have a view (that is actually part of a UINavigationControllers view) that i want to make a scrollview.
how do i do that?
could i do something like this:
UIScrollView * content = [[UIScrollView alloc] initWithFrame:self.view.bounds];
self.view = content
(obviously that doesn't work, but is there a way to do it like that)?
Yes, it is, you have to implement delegates, and set the contentSize. The best tutorial on scrollViews ever I found is:
http://www.raywenderlich.com/10518/how-to-use-uiscrollview-to-scroll-and-zoom-content
You are on a good way!
You can create the scroll view programmatically like you do and then add the existing view as a subview of this new scroll view, examine addSubview: (which works on all UIViews and subclasses like UIScrollView as well). I won't say this is the solution or even a clean one for that matter, but if you read about addSubview: you can at least figure out how to have a view live inside a scroll view...
I am working on an app, which actually works like MSPaint (something to draw lines, etc...).
I got a white UIView, basically where the user draws. On top of this UIView I set up a UIImage, which is gray, with a 0,4 alpha. I want this UIImage to be used as a blotting paper. The idea is to disable touch when the user put the palm of his hand on this area, so it's more comfortable to draw (multitouch is disabled, and with this "blotting paper" you won't draw something accidentally with your palm...)
Even if I bring the UIImage to the front, on top of the view, and even if I disable user interactions on this UIImage, it is still possible to draw on the UIView. , behind the UIImage (kind of strange!)
I do not understand what's happening, because, it seems that the image is transparent, and that the UIView "behind" is still active, even if she's overlaid by the UIImage?!
Any help/indication/idea would be much appreciated! Thank you :-)
Have you set the "userInteractionEnabled" property of the UIImage to "NO" ?
You may actually want to do the opposite. When you disable user interaction or touches, the view basically becomes invisible to touches and they are passed on to the next view.
In your case you do want userInteractionEnabled because you want the view to catch those touches.
You have to disable the user interaction on the UIImageView not the UIImage and it should work.
Edit:
Or you could be sneaky and just add an empty view over it. Use the same frame size so it overlaps perfectly and thats it. You'll be able to see everything you need and it's not a subview of it so there will eb no interaction and touches will get registered but won't have any effect. :P
No better ideas unless you post some of your code...
OK, so I managed to do what I wanted to! YAY!
I got 3 different classes :
StrokesViewController (UIViewController)-the view controller
StrokesView (UIView) - the view where the user draws the strokes.
BlottingPaper (UIView) - the blotting paper.
I got a XIB file "linked" to all three.
I created this new class, called "BlottingPaper", typed UIView. the .h and .m file are actually empty (I do import #import < Foundation/Foundation.h >)
User interaction is enable on BlottingPaper.
I do not use the exclusive touch on this class.
On the XIB file, I just put a view on top of StrokesView. I link it to BlottingPaper (modify the alpha as I want, blablabla...)
And that's it! When I put the palm of my hand on it, it doesn't draw anything on the area where my hand is, but I still can draw with my finger on the rest of the StrokesView!
In addition to Dancreek's response, you should be setting buvard.userInteractionEnabled = YES; so that it captures interaction.
You should also set buvard.exclusiveTouch = YES; so that buvard is the only view which will receive touch events.
When you remove buvard you should set buvard.exclusiveTouch = NO; so that other views will regain their ability to receive touches.
I have a quite big problem, I am really not able to solve myself.
The result should look like this:
This image was made with photoshop and is part of the interface I try to build.
In the middle you see something, that should be a list of projects, you should be able to scroll, if it the list is bigger then the view.
So I am making a scrollview like this: (for some reason I cannot do this in the interface builder and want this to work programmatically)
NSScrollView *projectsListView = [[NSScrollView alloc] initWithFrame:NSMakeRect(15, 2, 801, 588)];
[projectsListView setHasVerticalScroller:YES];
Then I create the content view and set a pattern image as backgroundcolor:
NSClipView *contentView = [[NSClipView alloc] initWithFrame:NSMakeRect(0, 0,
[projectsListView frame].size.width, [projectsListView frame].size.height+(98*2))];
[contentView setBackgroundColor:[NSColor colorWithPatternImage:[NSImage imageNamed:#"BoxLineBackground"]]];
[contentView setDrawsBackground:YES];
Then set the view as document view:
[projectsListView setDocumentView:contentView];
Should work, right?
However the content view gets clipped and looks like this while scrolling:
I tried this to fix it, but it does nothing:
[[projectsListView documentView] setCopiesOnScroll:NO];
I also tried this, but it causes the contentview not to scroll at all.
The image stays the same, but I can move the scroller normally.
[[projectsListView contentView] setCopiesOnScroll:NO];
If I try to set the contentview with setContentView: instead of using setDocumentView:
it may work, but the scroller is gone, so it is also not working correctly.
I would really like to use the patternimage method, because I cannot tell how long the list will be. It depends on the user.
An additional problem then would be to get the whole thing rounded, but that does not matter that much. I tried to use a transparent border image and to overlay the NSScrollView with it using an NSImageView, but again this causes corruption, because it clips and moves the overlaying parts of the image view together with the content of the scrollview.
Anyone having an idea, how to achieve this?
Thanks
Rather than re-inventing the wheel, this interface should be implemented with a view-based NSTableView. The table cell UI could then be created in Interface Builder and you could control the background of the cells using the various NSTableView delegate methods. NSTableView will handle redraws upon scrolling correctly.
To handle the pattern color, just make the background of your cell a custom subclass of NSTableCellView and implement your pattern drawing code.
Regardless of all this, the problem you are having is due to an NSScrollView drawing optimisation. You can turn this off by calling [[yourScrollView contentView] setCopiesOnScroll:NO] on your NSScrollView instance. You can also set this in Interface Builder, just un-check the Copies on Scroll checkbox.
I fixed the problem by setting the Background Color on the NSScrollView instead on the NSClipView.
I though the background would be static in that case and I need to set it for the content view for that reason, but it works pretty well and does scroll together with the content view.
And thanks for Rob Keniger's answer. I will probably try this out.
Imagine, there is a UIViewController with a UIScrollView in it. At the top of the view there is an UIImageView, some UILabels and other things. Furthermore, there is a UITableView which content is Dynamic Prototypes. I attach a picture to make it clear:
I haven't got a static amount of cells in the UITableView so it could be scrollable. My problem is the following: the UITableView scrolls in itself but I want to scroll the whole View. What is the best possibility to do that?
Possible solutions I've founded today
1) The first thing is: I create a UITableViewController and declare a header section in which I include all my labels, images etc. programmatically (I would love to use the interface builder for that...)
2) Another solution is to calculate the height of the view. I tried the best to do it like this way - but: without success. If this is the best way to do that: Can anybody give an example?
I would ditch the UIScrollView and just use a UITableView. You can add a UIView object as the tableHeaderView of the UITableView just by dragging it in in Interface Builder. Now since everything is part of the UITableView hierarchy, everything will scroll together as expected.
You could also try setting delaysContentTouches to NO on your scrollView. Depending on your setup, this may make the scroll view respond to the touch first instead of the table view.
From Apples UIScrollView Docs:
delaysContentTouches
A Boolean value that determines whether the scroll view delays the
handling of touch-down gestures.
#property(nonatomic) BOOL delaysContentTouches
Discussion
If the value of this property is YES, the scroll view delays handling
the touch-down gesture until it can determine if scrolling is the
intent. If the value is NO , the scroll view immediately calls
touchesShouldBegin:withEvent:inContentView:. The default
value is YES.
You'll have to (as you've mentioned) add the UIView containing the image and buttons to the actual UITableView. Embedding it in the scroll view will produce the undesired behavior that you're seeing.
I would recommend returning the UIView as the header view for the first section of your table view. You can do this by implementing the UITableViewDelegate method:
- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section;
If you maintain an IBOutlet to the view containing your image/labels, you can return it here.
this is same demo i hope its helps you from iphone sorce code library
http://developer.apple.com/library/ios/#samplecode/iPhoneCoreDataRecipes/Introduction/Intro.html
thank you