Is it possible to dim the current view in cocoa?On a certain action I want to make the screen a little darker and prevent the user from interacting with the screen.
From the idea given by #Lord Zsolt, the same can be implemented in OS X as:
Add the following code when you want to darken your window.
NSView *transparentBlackView = [[NSView alloc] initWithFrame:[[yourwindow contentView] frame]];
CALayer *viewLayer = [CALayer layer];
[viewLayer setBackgroundColor:CGColorCreateGenericRGB(0.0, 0.0, 0.0, 0.4)]; //RGB plus Alpha Channel
[transparentBlackView setWantsLayer:YES];
[transparentBlackView setLayer:viewLayer];
[[yourwindow contentView] addSubview:transparentBlackView];
Also don't forget to add QuartzCore.framework to your project. And import it in your class using #import<QuartzCore/QuartzCore.h>
Edit: I've only now noticed, it's OSX, not iOS. Though the idea should still be the same.
Disable user interaction:
[self.view setUserIntractionEnabled:NO];
Then add a UIView with black color, alpha like 0.2 above it.
UIView *transparentBlackView = [[UIView alloc] initWithFrame:self.view.frame]
[transparentBlackView setBackgroundColor:[UIColor blackColor];
[transparentBlackView setAlpha:0.2];
[self.view addSubview:transparentBlackView];
Then you can write a custom method, and use performSelector:afterDelay to remove transparentBlackView.
Related
I want to create any (particularly uiview) kind of element (uiimageview, uibutton, uilabel etc.,) that should be in askew or skew style.
Is that possible in xcode - objective-c?
If you want deep explanation:
1) go to google.com and search ASKEW or click here
2) like italic fonts
Advance thanks :)
UPDATED # 21/12/2015
I found uibezierpath that allow you to draw point to point if anyone know to draw uibezierpath add that answer in comment field.
You can have this view inside a askew view like this:
UIView *askewView = [[UIView alloc] initWithFrame:self.view.bounds];
UIView *exampleView = [[UIView alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
exampleView.backgroundColor = [UIColor redColor];
[askewView addSubview:exampleView];
askewView.backgroundColor = [UIColor whiteColor];
[self.view addSubview:askewView];
CGAffineTransform transform = CGAffineTransformRotate(askewView.transform, 0.1);//M_PI/4);
askewView.transform = transform;
I used 0.1 radians because I think that 45º is to much, but in comment have the PI/4 (45º).
Result:
I hope this can help you.
I am using this code proposed by Bartosz to add a mask to an UIImageView. It works fine.
#import <QuartzCore/QuartzCore.h>
CALayer *mask = [CALayer layer];
mask.contents = (id)[[UIImage imageNamed:#"mask.png"] CGImage];
mask.frame = CGRectMake(0, 0, 320.0, 100.0);
yourImageView.layer.mask = mask;
yourImageView.layer.masksToBounds = YES;
In addition, I want to animate the mask, e.g. sliding the mask to the right, so that at the end of the animation, the mask is not applied to the UIImageView any more.
In my specific case, the mask uses a fully transparent image, so the UIImageView is not visible at the initial state (which works fine), but is expected to be so at the end of the animation. However, the idea may be reused to any other use case were masks need to be animated.
The idea is to manipulate the x-origin portion of the frame of the mask. So, I came up with this code:
[UIView animateWithDuration: 0.2
delay: 0
options: UIViewAnimationCurveEaseInOut
animations:^{
CGRect maskFrame = yourImageView.layer.mask.frame;
maskFrame.origin.x = 320.0;
yourImageView.layer.mask.frame = maskFrame;
}
completion:^(BOOL finished){}];
Unfortunately, the mask is applied to the whole UIImageView at any time, it's not sliding to the right.
UPDATE 1:
This is the code I am actually using the set up the view and mask: It's a UITableViewCell.
APPCell.m (APPCell.h "extends" UITableViewCell)
#import "APPCell.h"
#import <QuartzCore/QuartzCore.h>
#interface APPCell()
#property (strong, nonatomic) UIImageView *menu;
#property (strong, nonatomic) CALayer *menuMask;
...
#end
#implementation APPCell
...
- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier
{
self.menu = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 320.0, 88.0)];
[self.menu setBackgroundColor:[UIColor clearColor]];
[self.menu setImage:[UIImage imageNamed:#"cell_back"]];
[self addSubview:self.menu];
self.menuMask = [CALayer layer];
self.menuMask.contents = (id)[[UIImage imageNamed:#"cell_mask"] CGImage];
self.menuMask.frame = CGRectMake(0, 0, 320.0, 88.0);
self.menu.layer.mask = self.menuMask;
self.menu.layer.masksToBounds = YES;
}
...
Instead of animating with the help of UIKit, I am now using implicit animation of CoreAnimation to move the mask layer:
APPCell.m
...
- (void)swipeLeft
{
self.menuMask.position = CGPointMake(-320.0, 0.0);
}
...
I can confirm that swipeLeft is called. I expect the mask "to be gone" and to see the [UIImage imageNamed:#"cell_back"]], which I do when I uncomment self.menu.layer.mask = self.menuMask.
Solution:
Instead of setting the content on the CALayer, I set the background color to white. This is the code I am using:
self.menuSubMenuMask = [CALayer layer];
self.menuSubMenuMask.backgroundColor = [[UIColor whiteColor] CGColor];
self.menuSubMenuMask.frame = CGRectMake(320.0, 0.0, 320.0, 88.0);
self.tableCellSubMenu.layer.mask = self.menuSubMenuMask;
self.tableCellSubMenu.layer.masksToBounds = YES;
In order to show the UIImageView the CALayer is applied to, the CALayer must NOT be "above" the UIImageView.
Animation with UIKit of UIViews is much more limited than using Core Animation directly. In particular what you are trying to animate is not one of animatable properties of a UIView. In addition as clarified in the View Programming Guide for iOS:
Note: If your view hosts custom layer objects—that is, layer objects without an associated view—you must use Core Animation to animate any changes to them.
This is the case in your example. You have added a CALayer to your view and UIKit will not be able to animate the result for you. On the other hand you can use Core Animation directly to animate the motion of your mask layer. You should be able to do this easily using implicit animation as described in the Core Animation Programming Guide. Please note that from the list of CALayer Animatable Properties that frame is not animatable. Instead you should use position.
You can achieve something you want by using CATransition, although this might not be the solution you want:
1) At first, set mask for your layer just as you did
2) When you want to remove mask and reveal your image, use the following code:
CATransition* transition = [CATransition animation];
transition.type = kCATransitionPush;
transition.subtype = kCATransitionFromRight;
transition.duration = 1.0;
[mask addAnimation:transition forKey:kCATransition];
imageView.layer.mask.contents = [UIImage imageNamed:#"black.png"].CGImage;
The main trick here - we created transition animation for our mask layer, so this animation will be applied when you change any (i'm not sure about any) property of mask layer. Now we set mask's content to completely black image to remove masking at all - now we've got smooth pushing animation where our masked image is going to the left and unmasked image is getting into its place
The easiest way is to use CoreAnimation itself:
CGPoint fromPoint = mask.position;
CGPoint toPoint = CGPointMake(fromPoint.x*3.0, fromPoint.y);
mask.position = toPoint; // CoreAnimation animations do *not* persist
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"position"];
animation.fromValue = [NSValue valueWithCGPoint:fromPoint];
animation.toValue = [NSValue valueWithCGPoint:toPoint];
animation.duration = 4.0f;
[mask addAnimation:animation forKey:#"position"];
I am currently building a Profile Object that can return a view with all the information of the user. I want to be able to reuse the code in many different places so I am trying to build it in an NSObject but when I add it as a subview of my view, I cannot click the buttons. The buttons are created with a rectangle and then have a UILabel put on top of them. If I copy the cody where I am trying to put it, it works. I also tried creating a delegate but that did nothing either.
EDIT
UIView *profile = [[UIView alloc] initWithFrame:CGRectMake(10.0, 0.0, 300.0, 175.0)];
UIView *votesView = [[UIView alloc] initWithFrame:CGRectMake(60.0, 125.0, 60.0, 50.0)];
UILabel *votesLabel = [[UILabel alloc] initWithFrame:CGRectMake(5.0, 0.0, 50.0, 40.0)];
votesView.backgroundColor = [UIColor lightGrayColor];
votesLabel.text = votes;
votesLabel.textAlignment = UITextAlignmentCenter;
votesLabel.backgroundColor = [UIColor clearColor];
votesLabel.tag = 2;
[votesView addSubview:votesLabel];
[profile addSubview:votesView];
Why are you subclassing an NSObject, you can subclass an UIView and implement all your views that are to be included,
Also, I am not able to see how you are adding a button, I can see just labels in your code.
But would suggest that you need to mention action and target, where for target you can add your class where it is called
[btn addTarget:<class where you will add UIView returned by your class> action:<SEL in your class where you will add UIView> forControlEvents:<UIControlEvents>]
I created an empty Cocoa app on Xcode for OS X, and added:
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
self.view = [[NSView alloc] initWithFrame:NSMakeRect(100, 100, 200, 200)];
self.view.wantsLayer = YES;
self.view.layer = [CALayer layer];
self.view.layer.backgroundColor = [[NSColor yellowColor] CGColor];
self.view.layer.anchorPoint = CGPointMake(0.5, 0.5);
self.view.layer.transform = CATransform3DMakeRotation(30 * M_PI / 180, 1, 1, 1);
[self.window.contentView addSubview:self.view];
}
But the rotated layer's background is clipped by the view's bounding area:
I thought since some version of OS X and iOS, the view won't clip the content of its subviews and will show everything inside and outside? On iOS, I do see that behavior, but I wonder why it shows up like that and how to make everything show? (I am already using the most current Xcode 4.4.1 on Mountain Lion).
(note: if you try the code above, you will need to link to Quartz Core, and possibly import the quartz core header, although I wonder why I didn't import the header and it still compiles perfectly)
It turns out that if the line:
((NSView *)self.window.contentView).wantsLayer = YES;
is added to the very beginning, then it works as expected:
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
((NSView *)self.window.contentView).wantsLayer = YES;
self.view = [[NSView alloc] initWithFrame:NSMakeRect(200, 200, 200, 200)];
self.view.wantsLayer = YES;
self.view.layer.backgroundColor = [[NSColor yellowColor] CGColor];
[self.window.contentView addSubview:self.view];
self.view.layer.anchorPoint = CGPointMake(0.5, 0.5);
self.view.layer.transform = CATransform3DMakeRotation(30 * M_PI / 180, 0, 0, 1);
}
So it looks like if all the views are made to be layer backed, then it works the same as it does on iOS. (If there is a quick way to make all views layer backed automatically, that'd be good).
the anchorPoint line cannot be moved before addSubview line, or else it is incorrect, although I wonder why that would make any difference.
The line self.view.layer = [CALayer layer]; can be removed if window.contentView is layer backed. Both the contentView and self.view don't need to set the layer, and I wonder why too.
The transform line cannot be before the addSubview line, or else it won't rotate, and I wonder why too.
The third thing is that, I thought if I go to Interface Builder and make the contentView a class of ContentView (subclassing NSView), and in its init method, do a self.wantsLayer = YES;, then it would work too, but it does not.
But anyway, the code above works, and I will update the reasons above why when I find out more.
Since the template of an OS X app in Xcode seems to be similar to an empty app template, the following is used to add a view and a button (trying not to use Interface builder for now):
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
NSView *view = [[NSView alloc] initWithFrame:NSMakeRect(100, 100, 100, 100)];
view.layer.backgroundColor = [[NSColor yellowColor] CGColor];
[self.window.contentView addSubview:view];
NSRect frame = NSMakeRect(10, 40, 90, 40);
NSButton* pushButton = [[NSButton alloc] initWithFrame: frame];
pushButton.bezelStyle = NSRoundedBezelStyle;
[self.window.contentView addSubview:pushButton];
NSLog(#"subviews are %#", [self.window.contentView subviews]);
}
Similar code on iOS should have produced a yellow box and a button, but the code above only produce a button, but the view won't show. Is there something wrong with the code above, and how to make it show the view with a yellow background?
Use setWantsLayer: method of NSView class.
NSView *view = [[NSView alloc] initWithFrame:NSMakeRect(100, 100, 100, 100)];
[view setWantsLayer:YES];
view.layer.backgroundColor = [[NSColor yellowColor] CGColor];
[self.window.contentView addSubview:view];
NSRect frame = NSMakeRect(10, 40, 90, 40);
NSButton* pushButton = [[NSButton alloc] initWithFrame: frame];
pushButton.bezelStyle = NSRoundedBezelStyle;
[self.window.contentView addSubview:pushButton];
NSLog(#"subviews are %#", [self.window.contentView subviews]);
To expand on the suggestion by Kevin Ballard, the classic way to do this is to subclass NSView and override the -drawRect: method. NSRectFill is a very convenient function for filling a rectangle without having to create a bezier path:
- (void)drawRect:(NSRect)rect
{
[[NSColor yellowColor] set];
NSRectFill(rect);
}
NSViews in Cocoa are, by default, not layer-backed. I suspect that if you type
NSLog(#"%#", view.layer);
you will see that it is nil.
In iOS, all views have layers. But on OS X, views don't have layers. In addition, there's 2 "modes" of layer-backed views on OS X. There's what's called a "layer-backed views" and a "layer-hosting view". A layer-backed view uses a CoreAnimation layer to cache drawn data, but you are not allowed to interact with the layer in any way. A layer-hosting view uses a CALayer that you explicitly provide, and you may mess with that layer all you want. However, with a layer-hosting view you may not add any subviews, or use the built-in NSView drawing mechanism. A layer-hosting view must only be used as the root of a CoreAnimation layer hierarchy.
Given all this, you should probably avoid using CoreAnimation at all for your view.
It's possible that an NSBox will do what you want. You can certainly set a fill color there, turn off the border, and set the style to custom. I'm just not 100% certain it will draw as a simple filled rectangle of color. Alternatively you can define your own NSView subclass that draws a color in -drawRect:.