I'm sure I'm missing something basic here. I'm trying out the CALayers 'hello world' code from:
http://www.raywenderlich.com/2502/introduction-to-calayers-tutorial
Doing the very first example. New single view project in xcode 4.2. No change to the nib/storyboard. Import QuartzCore. Add the following code to ViewDidLoad in the ViewController.m:
- (void)viewDidLoad
{
[super viewDidLoad];
self.view.layer.backgroundColor = [UIColor blueColor].CGColor;
self.view.layer.cornerRadius = 30.0;
self.view.layer.frame = CGRectMake(20, 20, 20, 20);
}
I run this (ipad 2 or ipad simulator) and get a full screen blue rectangle with rounded corners. What I hoped to get was a 20x20 blue rectangle offset by 20/20.
I'm clearly getting control over the views layer (as shown by the color and rounded corners). However, adjusting the frame seems to have no impact. I've NSLog'ed the frame before/after setting it, and it has changed. Is the frame of the root layer locked to the uiview frame?
I don't have a strong reason to change the views layers frame, I'm just trying to reason through what is going on. Hopefully this is an easy question...
Thanks!
Paul
Actually, the previous answer (you can't set uiview.layer.frame as it always fills the uiview) is close, but not quite complete. After reading the answer, I registered for the original site and to comment that the tutorial had issues. In doing so, I found that there were already comments that I hadn't seen in my first pass that addressed this. Using those, I started doing some testing.
The bottom line, if you move the self.view.layer.frame setting code from viewDidLoad to viewWillAppear, it works fine. That means that you can change the frame of the root layer of a view. However, if you do it in viewDidLoad it will be undone later.
However, the previous answer is still pretty close. I NSLog'ed the frame of the root layer and the frame of the view. Changing the root layer frame changes the view frame. So, the answer that the view.layer.frame always fills the view.frame is correct. However, setting the layer frame resets the view frame to match. (I'm guessing that uiview.frame property simply returns uiview.layer.frame...)
So, at some point in time between 2010 and today, something in the environment changed. Specifically, after viewDidLoad and before viewWillAppear the uiview/layer frame appears to be reset to the nib specified value. This overrides any changes in viewDidLoad. Changes made in viewWillAppear appear to stick.
Robin's answer got me on the right track, but I wanted to spell out the full answer.
The tutorial is wrong. Setting the frame of the view's main layer has no effect. The main layer is 'special' and will always fill the view's bounds. What you need to do is create a sublayer of the main layer like this:
- (void)viewDidLoad
{
[super viewDidLoad];
CALayer *newLayer = [[CALayer alloc] init];
newLayer.backgroundColor = [UIColor orangeColor].CGColor;
newLayer.cornerRadius = 20.0;
newLayer.frame = CGRectMake(100.0f, 100.0f, 200.0f, 200.0f);
[self.view.layer addSublayer:newLayer];
[newLayer release]; // Assuming you're not using ARC
}
Also, in your code a layer with width 20pt and height 20pt is too small to have rounded corners of 30pt anyway.
Related
I've been checking this site for many of my questions before but this is the first time I actually have to ask someting, so I hope I can make myself clear enough.
I have an App which is nearly finish. The main functionallity is in up and running. I'm only concern in making the whole App visually appealing. The App is maninly a database wich scientifical relevant data. I want the user to be able to store custom data in the DB and to do that I've created a "contact-like" view where the user can save some data. The view contains a table and inside this table, the cell have UITextFields. After entering the data, when the user presses a button, I want to animate the content of the textField to a cabinet-like icon. Very much like when you purchase something in the iTunes on a iOS device.
I've been able to do that animation in a "static" view (not a UITableView), playing around with starting point, end point and so on is a bit of a pain in the neck, but doable after all.
I'm doing the animation in a not really conventional way, I think, but actually very effecive. On the press of the button I create a UILabel, I set the text as the text of the textField and then I use viewAnimationWithDuration block to animate the label. Inside the block I also use Core Animation to animate the layer of the label over a path. Again, not conventional, but straight forward.
The problem I'm having is that I'm not able to create the label over the textField since it is in a UITableView. Mainly the problem is to know the position (or frame, or bounds, or position. I'm really confused already) of the textField and hence, the starting position of the path.
The code I'm using is as follows:
-(IBAction)saveCustom:(id)sender{
UILabel *imageViewForAnimation = [[UILabel alloc] initWithFrame:CGRectMake(l1, l2, l3, l4)];
imageViewForAnimation.text=label.text;
imageViewForAnimation.alpha = 1.0f;
imageViewForAnimation.backgroundColor=[UIColor clearColor];
imageViewForAnimation.textColor=[UIColor blackColor];
imageViewForAnimation.adjustsFontSizeToFitWidth=YES;
[self.view addSubview:imageViewForAnimation];
[UIView animateWithDuration:10.0
delay:0.0
options:UIViewAnimationOptionCurveEaseInOut
animations:^{
// Set up path movement Core Animation begins
CAKeyframeAnimation *pathAnimation = [CAKeyframeAnimation animationWithKeyPath:#"position"];
CGPoint endPoint = CGPointMake(310, 380); // final point
CGMutablePathRef curvedPath = CGPathCreateMutable();
CGPoint rootViewPoint = [imageViewForAnimation convertPoint:imageViewForAnimation.center toView:taula];
CGPathMoveToPoint(curvedPath, NULL, rootViewPoint.x, rootViewPoint.y); // initial point
CGPathAddCurveToPoint(curvedPath, NULL, 100, 100, 100, 100, endPoint.x, endPoint.y);
pathAnimation.path = curvedPath;
CGPathRelease(curvedPath);
pathAnimation.fillMode=kCAFillModeForwards;
pathAnimation.removedOnCompletion=NO;
pathAnimation.duration=10.0f;
pathAnimation.delegate=self;
[imageViewForAnimation.layer addAnimation:pathAnimation forKey:#"savingAnimation"];
[imageViewForAnimation release];
//Core Animation ends
imageViewForAnimation.transform=CGAffineTransformMakeScale(0.60, 0.60);
// imageViewForAnimation.alpha=0.2;
}
completion:^(BOOL finished){
[imageViewForAnimation removeFromSuperview];
} ];
}
Any help on how to proceed will be much appreciated.
Thanks in advance!
UPDATE:
I went to the Apple Tech Talks in Berlin. In the labs they got, I asked an engineer about that. He wondered that the code I showed him didn't work. I emailed to him and he'll be back to me.
The key thing is to transform the coordinates from the table, to the view.
A UITableView shows a number of UITableViewCells. If you want to customize the controls displayed in a cell, you can add additional controls to the contentView of a UITableViewCell. Depending on how complicated your needs are, you would do this in the UITableViewDelegate or by subclassing UITableViewCell. Just be aware that adding subviews to contentView will likely interfere with the built-on controls (e.g. textLabel or detailTextLabel).
To position your additional controls or animation effects, you can check the bounds of the cell's contentView. Add your controls as subviews of contentView, animate them, and don't forget to remove them when you no longer need them.
Seems pretty conventional animation to me. And yes, effective.
As to a solution, you just need to save some state info when the user requests a save. And draw your animation label on top of the table. Should be no major problems there as long as you have a view available, super view of the table maybe?
Beyond that, how is your UI setup with respect to this table? How is the save custom activated (does the save all data or a specific field, do you have selected cell which you can access to pull the needed origin of your animation data)?
Also, don't forgot to release your UILabel after you add it as a subview, you are leaking it in the code above.
Ok So I have this code, which allows me to put a background image in:
I would love to know how to size this, so on the iPhone 4 I can get a 320x480 size but make it nice with an image of 570.855.
self.view.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"background_stream-570x855.jpg"]];
I have tried this:
UIImageView *image = [[UIImageView alloc]
initWithImage:[UIImage imageNamed:#"background_stream-570x855.jpg"]];
[self.view sendSubviewToBack:streamBG];
image.frame = CGRectMake(0, 0, 320, 480);
Which works, however the problem is it's behind the view, so I can't see it. I could make the view clear, but it has objects on it that need to be displayed.
Any help would be most apretiated
There are multiple options to put Views at desired location.
[self.view sendSubviewToBack:streamBG]; //Sends subview to last position i.e. at the last
[self.view bringSubviewToFront:streamBG] //Brings subview to first position i.e. at the first.
[self.view insertSubview:streamBG atIndex:yourDesiredIndex];//Put at desired index.
This is not answer to your question, though it may help you to set your imageview to desired location.
Hope it helps.
To answer part of your question about sizing. You need to use 2 different images for your app if you want the full resolution of the retina display (iPhone4) You should provide a 320x480 image (i.e. myImage.png) for older iPhones and one at twice the resolution, 640x960, for the iPhone 4. Use the exact same name for the high res version but add an "#2x" to the end (i.e. myImage#2x.png). In your code all you ever have to call is the base name (i.e. myImage.png) the app will choose the correct image based on the hardware its running on. That will get you the best experience on your app.
On the other part about the background view visibility, you could make the background color clear ([UIColor clearColor]) on the view that is blocking it. That would leave the content visible in that view but the view its self would be clear. Alternatively you could just insert the background at a specific index as #Jennis has suggested instead of forcing it to the back.
I am using Cocoanetic's implementation of EGOTableViewPullRefresh.
It's a cinch to implement. Love it:
http://www.cocoanetics.com/2009/12/how-to-make-a-pull-to-reload-tableview-just-like-tweetie-2/
The only problem I'm having is with rotation. When the view rotates, the refresh header doesn't adjust for landscape mode. It sits left aligned, 320.0f units wide.
I have tried everything I can think of to adjust this properly. I set it as a property in PullToRefreshTableViewController and tried to set the frame the same way it is done in init. This failed. I tried to do it in this same controller in viewWillAppear. Failed.
Beyond this, I tried about 6 other methods not worth detailing. The problem seems to be that I'm using the wrong bounds, even though I'm making them relative to the view.
Nothing I do replicates what is seemingly easy in viewDidLoad:
refreshHeaderView = [[EGORefreshTableHeaderView alloc] initWithFrame:
CGRectMake(0.0f, 0.0f - self.view.bounds.size.height,
320.0f, self.view.bounds.size.height)];
It seems all I really need to do is increase the width. I tried something along the lines of this:
refreshHeaderView.frame = CGRectMake(refreshHeaderView.frame.origin.x, refreshHeaderView.frame.origin.y, 480.0f, refreshHeaderView.frame.size.height);
No luck.
The link at the top has the full, unmodified source code for what I'm using.
What about just setting the UIView.autoresizingMask to UIViewAutoresizingFlexibleWidth?
Anyone ever seen the problem of [UIColor initWithPatternImage] ignoring the alpha values of the PNG? If so, what's the best fix?
I am using a png as a background layer to my array of button objects and it contains several pre-set alpha values per pixel in the image that is to be used as a texture background. It loads fine as a pattern/texture-color, but it comes up with all key transparent area as opaque black.
It is important that I get the right alpha values so that the button images shows correctly. The button frames do not include the alpha shadows from the background as that is not the "clickable" portion of the button. Additionally, my button object's images and background images also makes use of transparency, so it really needs to have a clear background directly behind each button to let the proper true current color settings come through (lowest layer UIView will have its background color set to the current user's selected color). Setting just the single alpha value for the UIView layer containing this texture does not work for my needs either.
Any help would be appreciated. My current workaround would be to use fully-blown, repeatedly-programmed layout of several UIImageView using the png, instead of a single UIView with the pattern fill.
Here is a snippet of code, but it's pretty standard for turning a UIImage into a UIColor for use as a pattern/texture color:
UIView *selectorView = [[UIView alloc] initWithFrame:CGRectMake(0,0,320,320)];
UIColor *background = [[UIColor alloc] initWithPatternImage:[UIImage imageNamed:#"SelectorViewBackground.png"]];
selectorView.backgroundColor = background;
[mainView addSubview:selectorView]; // pattern background layer. Add UIButtons on top of this selectorView layer
[self addSubview:mainView]; // current user selected color set in mainView.
[selectorView release];
[background release];
I had the same problem with setting a background on a UIView with some transparancy,
this is how I solved it:
theView.backgroundColor = [UIColor clearColor];
theView.layer.backgroundColor = [[UIColor alloc] initWithPatternImage:[UIImage imageNamed:#"the_image_with_transparancy.png"]].CGColor;
This is probably related to:
Tiled Background Image: Can I do that easily with UIImageView?
Basically, try setting:
[view setOpaque:NO];
[[view layer] setOpaque:NO];
No I've never had an issue with this. I use code like the above all the time for apps (though often I use it in conjunction with a layer instead of a view but that shouldn't make a difference with transparency being recognized) and always have had transparency work fine.
I'd look into your PNG file. I've noticed iOS sometimes being finicky with certain PNG options/types (like an 8 bit PNG with 8 bit transparency). Make sure your PNG is saved as 24 bit with 8 bit transparency (32 bit total).
Also, stupid question, but have you verified there isn't anything black in the view/layer hierarchy behind your PNG? Sometimes it's the stupid things like that
For those who might need the work-around code where the background patterns can be laid out as rows in a UIScrollView, here it is (adjusted to remove confidentiality concerns, should work if variables properly set prior to call).
Note that there should be ways to reuse just the one allocated instance of UIImageView multiple times to either save memory or load times but time-to-market is my No. 1 driver right now. Enjoy the journey :)
UIImageView *selectorView;
for (int i = 0; i < numRows; ++i) {
selectorView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"SelectorViewBackground.png"]];
selectorView.frame = CGRectMake(0, i * patternHeight, patternWidth, patternHeight);
[mainView addSubview:selectorView];
[selectorView release];
}
Once again I've searched for about 45 minutes for an answer to this question and I thought I might have found the answer but then the situation I was reading wasn't exactly like the one I'm running into.
when I add my view it seems that it's not completely covering the window I was able to get rid of the status bar at the top but there is a section of space at the bottom that the view is not covering
alt text http://img177.imageshack.us/img177/8844/picture1zjv.png
as you can see from the screenshot there is an orange bar...it's orange because I know what it actually is under there (it's the viewController's view but everything I try I can't seem to get the added view to cover the screen.
this is the only code that's run
(void)viewDidLoad {
[super viewDidLoad];
[self.view addSubview:mainMenu];
}
Any help would be appreciated.
There are a few things that might be going wrong:
Your frame might be too short. In viewDidLoad: you can add a debug statement to check its height:
NSLog(#"Height is %f", self.view.frame.size.height);
It looks like you want that value to be 480, the full height of the screen.
Your origin might be too high. Similarly check your y offset:
NSLog(#"y origin is %f", self.view.frame.origin.y);
It looks like you want that value to be 0.
The origin of your superview might be too high. Assuming you this view only has one superview, this code will help check the absolute coordinates of your view's origin:
CGPoint absoluteOrigin = [self.view convertPoint:self.view.frame.origin
toView:self.view.superview];
NSLog(#"y origin in superview is %f", absoluteOrigin.y);
You can just tag on a few extra .superview's to find out the coordinates in terms of the prior views.
By the way, instead of just using 480 as a magic number in your code, you might want to do something like this to get the full height:
CGRect appFrame = [[UIScreen mainScreen] applicationFrame];
CGFloat screenHeight = appFrame.size.height;
The applicationFrame property takes into account whether or not the status bar is displayed.
You should post your code, but in general, you can make a UIView fill the screen as follows:
UIView *foo = [[UIView alloc] initWithFrame:CGRectMake(0,0,320,480)];
And you can set the frame later:
foo.frame = CGRectMake(0,0,320,480);
To fill the screen, you should use a 320 x 480 Rectangle, at origin (0,0). That's what that CGRectMake function above creates.
I've had this problem before, I fixed it by just moving the view down 20 pixels...
When you use interface builder it has that nifty little "simulate status bar" or "simulate toolbar" feature but I think its kind of finnicky.
Both Andrew and Tylers answers should work though, no shame in doing things programmatically :). If you are creating the stuff in interface builder, just do Andrew's second line though, don't need to reinitialize.
Ok, well I figured it out and now I feel kind of stupid...I went back to IB and realized that the height of each view was set at 460 and not 480...you guys did give me a bunch of good information and I appreciate it all. I wish I could mark them all as answers.
Thank you again,
BWC