I have a view i want to overlay on top of another. It will be smaller and not take up the whole screen, and so it's important that the view behind can still be seen. How do i do this?
If you lay another view on top of an existing view and set the rect containing the new view to some size smaller than the screen, the view in back will still be seen. Just call initWithFrame:(your CGRect size) then your [mainView addSubview:newview]. This should add your new view on top of your existing one.
Related
I am trying to generate a scroll controller in a window with the UIScrollView class, which will contain numerous UIButtons, placed vertically. I set the size of the scroll view equal to the current view controller's root view, so that the scroll view covers the entire visible window. Then I generate the UIButtons I am going to add to the scroll view: I add each UIButton just in the below of the previous UIButton and I add the height of the current UIButton to a variable called "totalContentHeight". Finally, I set the height of the contentSize of the scroll view to this value, in the following line of code:
self.scrollViewForNewsButtons.contentSize = CGSizeMake(self.view.frame.size.width, totalContentHeight);
totalContentHeight is equal to numOfButtons*eachButtonsHeight after I add all the buttons to the scroll view.
The problem is, in the simulator, when I run the app and scroll until the end of the last button and release the mouse, the last two buttons bounces back such that they lie outside of the visible window. It is somewhat hard to express with mere words, so here are the images:
1)This is what I get when I scrolled until the end of the content and held the content at the last possible position it could be pushed:
2)This is what I get after I released the mouse and the scroll view bounced back to its final position:
As you can see, the last two buttons are drawn outside of the visible area. It is like the scroll view's area covers the whole window plus the button area of the IPhone. I could not find a reasonable explanation for this. Am I setting the area size wrong or am I missing something else?
just set content size with calculation with your total button and its height...For Ex..
float yheight = totalButton * yourButtonHeight;
[yourScrollView setContentSize:CGSizeMake(320, yheight + 44)];
try this code...
And if you set the scrollview frame size the same as
self.view.bounds
I have a UIViewController that I designed in Interface Builder. near the top of the View it has a UIImageView and then some other Views (Text etc) below. These are set to anchor to the top of the view.
In code when the view loads I remove the UIImageView in certain circumstances but it still seems to take space or the view's below don't spring up to the top based on their Anchor.
How can I make the Views below move up if the View above is removed?
You can change the frame of the other elements in the view.
in the viewDidLoad method you can use something like that:
-(void)viewDidLoad{
if(imageVisible){
otherElements.frame = CGRectMake(....);
}else{
otherElements.frame = CGRectMake(....);
}
}
I don't know what is the structure of the view, but you might consider nesting all of the other elements in one view so you could change all the elements positions in one command.
Unlike the Android view hierarchies, iOS view hierarchies are all developed in absolute coordinates. When you say a subview is anchored to the top, that means that if the size of the parent view changes, your view will stay in the same relative position to the top of the screen.
In order to make your views below the image view move up when the image is hidden or removed, you will have to manually arrange them yourself to account for the offset
There is a xib with a a dark view (called calendarView) in it
Next is I am adding a subView called calendar ( this is a calendar view from this page )
[self.calendarView addSubview:calendar];
And the result is :the calendar is added but it is cover the calendarView
My question :
what will happen when you try to add a bigger view into a small view.
How to make a bigger view fit in the the small view.
in general the subview will draw itself bigger then the superview. if you dont want that to happen you should set the subview's frame to smaller or equal to the superview's bounds.
if the subview is a costume class you made, you should probably change it to be in the right size, otherwise I think the best way to do it is with transform
Nothing exceptional. The bigger view will be placed accordingly to it's frame.
Simple, just by equaling their sizes (and the added view's origin to be (0,0) ).
I have a view (myContactViewController.xib) which contains a Scroll View (created in Interface Builder, and which takes takes up the entire height of the window and is 960px in width — ie. 3 x the width of a single window). I'm using the Scroll View, with paging, for horizontal navigation of three subviews (all three subviews are 320x460, ie. the entire size of the window). I have created these three subviews via Xcode (command-N), and so for each subview I have a .h, .m and .xib. I have used Interface Builder to build the layout (just some text and a picture for now — but, will eventually contains some buttons) for their views.
Programmatically, I would like the load these three views into my Scroll View, specifying their location within. The .xibs for each of the views I'd like to load into the scroll view are as follow: myContactSub1.xib, myContactSub2.xib and myContactSub3.xib).
I'm wondering if anyone would be willing to explain how to do this?
Thanks,
Kristin.
Sure it's very easy. First set the frame for the subview. The frame specifies where in the superview you want it to appear and is a CGRect. So you might use CGRectMake(0, 0, 320, 460) for the first subview. Then add it to the UIScrollView with addSubview:. Here's an example:
mySubView.frame = CGRectMake(0, 0, 320, 460);
[myScrollView addSubview:mySubView];
This assumes you have a pointer to these views, using IBOutlets. If you need help doing this read up on Xcode Integration
Also take a look at View Geometry
I have just started learning objective-C and the iphone sdk and I have a question that I hope someone can help shed some light on.
What is the difference in the following:
self.view = someView;
and
[self.view addSubView: someView];
Say for example, in a simple app, where we have only one controller and one container view (has a few image subviews).
What is the difference between the two statements? The reason that I'm asking is because I was tinkering around in some sample code and I noticed the view was being initialized with images as subviews like so:
if (self = [super initWithFrame:CGRectZero])
{
//adds some images as subviews here
}
As I understand it the initWithFrame: CGRectZero, creates a frame with size at [0,0,0,0] (essentially invisible).
When I directly set the view with
self.view = someView;
I notice the view actually displays the image. But when I add the view to as a subview of controller's 'default' view, it doesn't. So basically my question is, whats going on behind the scenes? Why is the first method "resizing" the frame and the second one not doing the same thing.
What you see on the screen of your iPhone is almost always a hierarchy of views.
When you look at, say, your inbox in Mail, you're seeing a bunch of views. There's a big containing view.[1] Within that, there's a navigation bar view, a table view, and a toolbar view. Within the navigation bar view, there's a button view on each side and a label view in the middle. Inside the table view, there are a bunch of table cell views, and each of those cells has several label views. The toolbar has five button views. I could go further and talk about the views inside those buttons and so on, but I'm sure you get the idea.
The view above any given view is its superview; the views below it are its subviews. So a table cell view has a table view as its superview and a bunch of label views as its subviews. The top view, the one that has all the other views inside it, is called the root view.
Each view has its own drawing surface. The rectangle formed by that drawing surface is called the frame. The frame of a view is relative to the frame of its containing view. So if one of our table cell's label subviews has its frame at (0,0), that means it will be in the table cell's top left corner, even if the cell is halfway down the screen.
When you're writing a view controller, self.view is that root view I mentioned earlier; all the other views are subviews of that one (or subviews of its subviews, etc.). One of the features of a view controller is that it automatically resizes its self.view to fit the screen. (The available area will be smaller in the middle of a phone call: the status bar is twice as high then, so there's less space for your app. It will also be smaller if your view controller is being managed by a navigation controller or tab bar controller, but that's a different story.) But just because you resize its root view doesn't mean that the root view's subviews will automatically resize. To do that, you need to set their autoresizing mask (a property which tells the view how it should react when its superview changes size):
someView.autoresizingMask = UIViewAutoresizingFlexibleWidth
| UIViewAutoresizingFlexibleHeight;
(There's a graphical way to set up the autoresizing mask in Interface Builder—click the ruler icon in the inspector window and look at the "Autosizing" section.)
Even that's not enough, though, if someView isn't the right size to start with. To do that, adjust its frame before you add it as a subview of self.view:
someView.frame = CGRectMake(
0, // all the way to the left
0, // all the way at the top
self.view.frame.size.width, // same width as the root view
self.view.frame.size.height, // same height too
);
So why would you ever use subviews if you have to do all this twiddling that the root view does for you? Simple: you can only have one root view, but one view is almost never enough for what you need to do. If you really need only one view, of course, you can just set it as the root view and go on your merry way, but chances are, things are more complicated than that.
[1] I'm simplifying a bit here, but that's fine for right now.
When you add a view as a subview, you need to make sure that you're actually adding to an existing view.
self.view = view sets the controller's view. Without this (either in code or done with a XIB) you'll never see anything as the controller has no view to show.
[self.view addSubView: someView] assumes that self.view is already set. If it doesn't, you're adding someview as a subview of nil, and it will never get seen.
Basically, think of self.view as the big container, and all the subviews are just pieces inside of it. If you don't need any subviews, setting self.view to a UIImageView or UIWebView is fine. If you do need subviews, you'll need a big, empty container view in which to put them.
In your case, I'm betting self.view is never set, and you're adding your image views to nil.
Setting the view controller "view" property only changes the view it is managing.
Adding a view as a subview of another view, actually adds the subview underneath the other view.
They are very different things, as one adjusts a view controller and the other alters a view hierarchy.
As a guess, the reason you didn't see anything the first way was the frame for the subview you were adding was CGRectZero (0 in size).