How to make Drawing on Fully Transparent View Visible - ios

I am using Quartz for drawing as in custom UIView say "Paint"
I have controller view "viewC"
I did
[self.view addSubView:somePaintInstance]; in my viewC at some event
Now when i am drawing or painting , the default background is "black" for Paint.
I want to do a Full Transparent Painting/Drawing on top of my "viewC" view
So i did
somePaintInstance.alpha=0.5; (before adding it as subview)
But that also make my drawing/painting transparent with the Paint's Background , so if i make it fully transparent (alpha = 0.0) , i couldn't see the drawing itself with the paint's view
What i tried and not working:
somePaintInstance.setbackgroundcolor
somePaintInstance.opaque
Other answers on web are also NOT concrete for this kind of implementation
I looked the answer by rob here:
How to add a transparent gradient mask to a context
But Still not clear how do i implement exactly what i want?
Let me know other details if required
Regards,

I tried to set a background with alpha value 0 or to work with StartTransparentLayer. None of that worked.
What worked for me was to set the views opaque property to NO.
In my view's initializer i put the following code:
-(id)initWithFrame:(CGRect)frame {
if (self = [super initWithFrame:frame]) {
// set default values
self.colorNormal = [UIHelper ricolaYellow];
self.colorActice = [UIColor colorWithHexString:CIRCLE_COLOR_ACTIVE];
self.capacities = nil;
self.opaque = NO;
}
return self;
}

This line should work,
somePaintInstance.backGroundColor = [UIColor clearColor];

Related

Making transparent Circles in iOs

I want to create a black UIView with transparent circles.
I think about create one view (with black color and transparence 50%), and add multiple circles inside of it, but I don't know how to set the transparence for each. I know how to create a circle View (an example: how to draw a custom uiview that is just a circle iphone-app).
I want to do is something like iShowcase library but with multiple dots:
Any clue? thanks.
SOLVED
I took a look to the code of iShowcase library and I solved my probblem. now, I am working in a library based in iShowcase library.
I will post here when I finish it.
Please have a look of below link hope this will helpful for you.
Link : Here is Answer to set shadow in your view.
Use alpha for your circleView. As in your link example,then add as subviews in yourmainview:
UIView *circleView = [[UIView alloc] initWithFrame:CGRectMake(10,20,100,100)];
circleView.alpha = 0.5;
circleView.layer.cornerRadius = 50;
circleView.backgroundColor = [UIColor whiteColor];
[yourmainview addSubview: circleView];
Btw in your picture I think white circles have 100% alpha. You can use individual alpha for each circleView, or use a randomizer :)
As for updated example why don't you add more buttons and showcase in your h file, synthesize them and use multiple instances .... showcase setupShowcaseForTarget:btn_custom_1 title:#"title" details:#"other"]; ? I think you should modify main classes, becouse what you want are different containerView for multiple views [circles].
Using modifyed iShowcase.m [- (void) calculateRegion], and different views as containers, I was able to make something like: http://tinypic.com/view.php?pic=2iwao6&s=8#.VLPTRqYsRE8 So the answer is: use custom views for multiple showcase [ex [showcase2 setContainerView:self.view2];], then custom frame for each showcase [ showcase2.frame = CGRectMake(0,0,100,100);] I don;t habe time to fine tuning the example, but yes, you can achieve desired result...
I finally solved my question inspired by iShowCase library I did this simple class and Upload to github.
https://github.com/tato469/FVEasyShowCase
Simplest what you can do is to have your main view (black 50% transparant) and add shapes to the mask layer of that.
So basically:
//Set up your main view.
UIView* mainView = [UIView new];
mainView.backgroundColor = [UIColor blackColor];
mainView.alpha = 0.5;
UIView* circle1 = [YourCircleClassHere new];
UIView* circle2 = [YourCircleClassHere new];
UIView* circle3 = [YourCircleClassHere new];
UIView* container = [UIView new];
[UIView addSubview:circle1];
[UIView addSubview:circle2];
[UIView addSubview:circle3];
//Make a new layer to put images in to mask out
CALayer* maskLayer = [CALAyer layer];
//Assign the mask view to the contents layer.
maskLayer.contents = (id)container;
//This will set the mask layer to the top left corner.
maskLayer.frame = CGRectMake(0,0,container.frame.size.width,container.frame.size.height);
//Lastly you assign the layer to the mask layer of the main view.
mainView.layer.mask = maskLayer;
//Applies basically the same as clipToBounds, but a bit reversed..
mainView.layer.mask = true/false;
On a sidenote:
I achieved this with images "contents = (id) [UIImage CGImage]", but I'm sure it should work with UIViews as well.
Also mind some mistakes, since I just wrote this from my mind, also I didn't test this out.. So keep me updated if it works/!works ^_^

Customize Button shape in ios 7.1

Apple has added Button shape feature in ios 7.1. But I need to make it disable for my app or change its default color, shape to match UI of my app. It is possible without using custom type button? Please help me.
Sub class the button and try which shape you want....
#import "YourButton.h"
#import <QuartzCore/QuartzCore.h>
#implementation YourButton
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
}
return self;
}
- (void)awakeFromNib
{
[super awakeFromNib];
CALayer *mask = [CALayer layer];
mask.contents = (id)[[UIImage imageNamed:#"ge.png"] CGImage]; // ge is the black & white png image
CGSize size = self.frame.size;
mask.frame = CGRectMake(0, 0, size.width, size.height);
self.layer.mask = mask;
[self.layer setMasksToBounds:YES];
}
#end
For your reference sample is attached Here
These features reflect on apples default button control(may be nav bar).
You don't need to worry about,these features are not app specific but for all apps.
If you want to ignore, don't use default button, instead go with custom.
P.S. After editing question by OP:
You can't achieve this without using custom implementation.
For More:reference
Well you can make it custom type & use image according to the way you want to view that.
IF you use a UINavigationBar or UIToolbar as the of the button then you will get a slightly darker color of the bar's tint color.
Otherwise you can get an underline whats color matches the text color, so i think this should not bother you. Leave it as it is.

Achieving bright, vivid colors for an iOS 7 translucent UINavigationBar

iOS 7.1 UPDATE: Looks like the workaround for modifying the alpha channel in the UINavigationBar has been ignored in this update. Right now, the best solution seems to be to just 'deal with it' and hope that whatever color you choose can render a translucent effect. I am still looking into ways of getting around this.
iOS 7.0.3 UPDATE: The GitHub library we created has been updated to slightly work around this issue when using iOS 7.0.3. Unfortunately, there is no magic formula to support both colors created in iOS 7.0.2 and earlier and iOS 7.0.3. Seems like Apple improved the saturation, but at the cost of opacity (since the blurred translucency is dependant on the opacity level). I, along with a few others, are working on creating a much better fix for this.
I'm sure many people have already come across the problem where iOS 7 tends to desaturate the color of a UINavigationBar that is translucent.
My goal is to achieve a UINavigationBar with this tint color, but translucent:
However, with translucency, I'm getting this. The background view is white, which I understand will make this view a bit lighter:
Is there any way to achieve the original color while still having translucency? I've noticed Facebook has been able to get their bar to be their rich, blue color, as displayed here:
..so I know there has to be some way. Background views obviously make a difference here, but most of their content is also gray/white. It seems that regardless of whatever bar tint color you put in, you are unable to get vivid colors under translucency.
Updated with solution.
Here's the solution that I ended up coming up with. I took aprato's solution and then encompassed the custom UINavigationBar within a UINavigationController subclass. I have created a repository that has this implementation listed below, along with an example app.
////////////////////////////
// CRNavigationBar.m
////////////////////////////
#import "CRNavigationBar.h"
#interface CRNavigationBar ()
#property (nonatomic, strong) CALayer *colorLayer;
#end
#implementation CRNavigationBar
static CGFloat const kDefaultColorLayerOpacity = 0.5f;
static CGFloat const kSpaceToCoverStatusBars = 20.0f;
- (void)setBarTintColor:(UIColor *)barTintColor {
[super setBarTintColor:barTintColor];
if (self.colorLayer == nil) {
self.colorLayer = [CALayer layer];
self.colorLayer.opacity = kDefaultColorLayerOpacity;
[self.layer addSublayer:self.colorLayer];
}
self.colorLayer.backgroundColor = barTintColor.CGColor;
}
- (void)layoutSubviews {
[super layoutSubviews];
if (self.colorLayer != nil) {
self.colorLayer.frame = CGRectMake(0, 0 - kSpaceToCoverStatusBars, CGRectGetWidth(self.bounds), CGRectGetHeight(self.bounds) + kSpaceToCoverStatusBars);
[self.layer insertSublayer:self.colorLayer atIndex:1];
}
}
#end
////////////////////////////
// CRNavigationController.m
////////////////////////////
#import "CRNavigationController.h"
#import "CRNavigationBar.h"
#interface CRNavigationController ()
#end
#implementation CRNavigationController
- (id)init {
self = [super initWithNavigationBarClass:[CRNavigationBar class] toolbarClass:nil];
if(self) {
// Custom initialization here, if needed.
}
return self;
}
- (id)initWithRootViewController:(UIViewController *)rootViewController {
self = [super initWithNavigationBarClass:[CRNavigationBar class] toolbarClass:nil];
if(self) {
self.viewControllers = #[rootViewController];
}
return self;
}
#end
iOS 7.0.3 UPDATE: As you see above 7.0.3 changed things. I've updated my gist. Hopefully this will just go away as people upgrade.
Original Answer:
I ended up with a hack combining the two of the other answers. I'm subclassing UINavigationBar and adding a layer to the back with some extra space to cover if any of the various height status bars are up. The layer gets adjusted in layout subviews and the color changes whenever you set barTintColor.
Gist: https://gist.github.com/aprato/6631390
setBarTintColor
[super setBarTintColor:barTintColor];
if (self.extraColorLayer == nil) {
self.extraColorLayer = [CALayer layer];
self.extraColorLayer.opacity = self.extraColorLayerOpacity;
[self.layer addSublayer:self.extraColorLayer];
}
self.extraColorLayer.backgroundColor = barTintColor.CGColor;
layoutSubviews
[super layoutSubviews];
if (self.extraColorLayer != nil) {
[self.extraColorLayer removeFromSuperlayer];
self.extraColorLayer.opacity = self.extraColorLayerOpacity;
[self.layer insertSublayer:self.extraColorLayer atIndex:1];
CGFloat spaceAboveBar = self.frame.origin.y;
self.extraColorLayer.frame = CGRectMake(0, 0 - spaceAboveBar, CGRectGetWidth(self.bounds), CGRectGetHeight(self.bounds) + spaceAboveBar);
}
The behavior of tintColor for bars has changed on iOS 7.0. It no longer affects the bar's background and behaves as described for the tintColor property added to UIView. To tint the bar's background, please use -barTintColor.You can use following code to make the app work with both ios6 and ios7.
if(IS_IOS7)
{
self.navigationController.navigationBar.barTintColor = [UIColor blackColor];
self.navigationController.navigationBar.translucent = NO;
}
else
{
self.navigationController.navigationBar.tintColor = [UIColor blackColor];
}
IS_IOS7 is a macro which is defined in pch file as follows.
#define IS_IOS7 ([[UIDevice currentDevice].systemVersion floatValue] >= 7.0)
I didn't come up with this solution but it seems to work fairly well. I just added it to viewDidLoad on my subclass of UINavigationController.
Source: https://gist.github.com/alanzeino/6619253
// cheers to #stroughtonsmith for helping out with this one
UIColor *barColour = [UIColor colorWithRed:0.13f green:0.14f blue:0.15f alpha:1.00f];
UIView *colourView = [[UIView alloc] initWithFrame:CGRectMake(0.f, -20.f, 320.f, 64.f)];
colourView.opaque = NO;
colourView.alpha = .7f;
colourView.backgroundColor = barColour;
self.navigationBar.barTintColor = barColour;
[self.navigationBar.layer insertSublayer:colourView.layer atIndex:1];
One low-fi way would probably be pinning a UIView that is the height of the Navigation Bar to the top of the view behind the bar. Make that view the same color as the navigation bar but play with the alpha until you get the desired effects:
UIView *backgroundView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, CGRectGetWidth(self.navigationController.navigationBar.frame), 64)];
backgroundView.backgroundColor = [UIColor colorWithRed:0.0 green:0.0 blue:1 alpha:.5];
[self.navigationController.view insertSubview:backgroundView belowSubview:self.navigationController.navigationBar];
UIView behind
(Changed color from lower examples to emphasis transparency. Transparency/blurring is more noticeable when in movement.)
Subclassing the UINavigationBar and placing that same view above the background but behind everything else will probably achieve similar results while being less hacky.
Another solution I've seen tossed around is playing with the alpha of the UINavigationBar:
self.navigationController.navigationBar.alpha = 0.5f;
Edit: Actually, after testing it seems like this doesn't provide the intend behavior (or any behavior):
.8 alpha
Unadjusted alpha
Obviously, you will only want to do this on iOS 7 devices. So, add some version check before you implement any of these.
Instead of creating your UIColor object in the RGB format, use HSB and increase the saturation parameter. (Credits to Sam Soffes who describes this method here)
navigationBar.barTintColor = [UIColor colorWithHue:0.555f saturation:1.f brightness:0.855f alpha:1.f];
Note: This solution is a tradeoff and doesn't work well for colors with high saturation.
To pick the HSB color from your design you can use a tool like ColorSnapper which allows you to simply copy the UIColor HSB format.
You can also try the UIColor Category (GitHub Link) from David Keegan to modify existing colors.
The problem has now been fixed by Apple in the new 7.0.3 release.
I used #aprato's solution but found a few corner cases where the new layers from new VCs (eg. UINavigationItemButtonViews, UINavigationItemViews, etc) would be automatically inserted into a position below the extraColorLayer (which would cause those title or button elements to be affected by the extraColorLayer and thus fainter in color than they normally would be). So I adjusted #aprato's solution to force the extraColorLayer to stay at the index position 1. At index position 1, the extraColorLayer stays right above the _UINavigationBarBackground, but underneath everything else.
Here's my class implementation:
- (void)setBarTintColor:(UIColor *)barTintColor
{
[super setBarTintColor:barTintColor];
if (self.extraColorLayer == nil)
{
self.extraColorLayer = [CALayer layer];
self.extraColorLayer.opacity = kDefaultColorLayerOpacity;
[self.layer insertSublayer:self.extraColorLayer atIndex:1]; // This way the text comes out clear
}
self.extraColorLayer.backgroundColor = barTintColor.CGColor;
}
- (void)layoutSubviews
{
[super layoutSubviews];
if (self.extraColorLayer != nil)
{
self.extraColorLayer.frame = CGRectMake(0, 0 - kSpaceToCoverStatusBars, CGRectGetWidth(self.bounds), CGRectGetHeight(self.bounds) + kSpaceToCoverStatusBars);
}
}
- (void)insertSubview:(UIView *)view aboveSubview:(UIView *)siblingSubview
{
[super insertSubview:view aboveSubview:siblingSubview];
[self.extraColorLayer removeFromSuperlayer];
[self.layer insertSublayer:self.extraColorLayer atIndex:1]; // This way the text comes out clear
}
- (void)insertSubview:(UIView *)view atIndex:(NSInteger)index
{
[super insertSubview:view atIndex:index];
[self.extraColorLayer removeFromSuperlayer];
[self.layer insertSublayer:self.extraColorLayer atIndex:1]; // This way the text comes out clear
}
- (void)insertSubview:(UIView *)view belowSubview:(UIView *)siblingSubview
{
[super insertSubview:view belowSubview:siblingSubview];
[self.extraColorLayer removeFromSuperlayer];
[self.layer insertSublayer:self.extraColorLayer atIndex:1]; // This way the text comes out clear
}
I've improved your code in my fork: https://github.com/allenhsu/CRNavigationController
With my modification, the result color on screen (picked on white background) will be exactly the same value passed into setBarTintColor. I think it's an amazing solution.
None of these hacks are required :). Simply set:
self.navigationController.navigationBar.translucent = NO;
For iOS 7, the default translucency has been kept to TRUE.
On a related note, you can set your title text color (with shadow) easily via:
NSShadow *titleShadow = [[NSShadow alloc] init];
titleShadow.shadowOffset = CGSizeMake(0.0f, -1.0f);
titleShadow.shadowColor = [UIColor blackColor];
NSDictionary *navbarTitleTextAttributes = #{NSForegroundColorAttributeName: [UIColor whiteColor],
NSShadowAttributeName: titleShadow};
[[UINavigationBar appearance] setTitleTextAttributes:navbarTitleTextAttributes];
I came across this Q/A while trying to setup an uniformly colored navigation bar with transparency DISABLED on iOS 7.
After experimenting a while with barTintColor I figured out that a very easy way of having an opaque navigation bar is to make a single pixel image of the desired color, make a stretchable image out of it, and setting it to the backgroundImage of the navigation bar.
UIImage *singlePixelImage = [UIImage imageNamed:#"singlePixel.png"];
UIImage *resizableImage = [singlePixelImage resizableImageWithCapInsets:UIEdgeInsetsZero];
[navigationBar setBackgroundImage:resizableImage forBarMetrics:UIBarMetricsDefault];
Three lines of code, very simple and works BOTH on iOS 6 and iOS 7 (barTintColor is unsupported on iOS 6).
Theres a great Dropin UINavigationController replacement available from Simon Booth available at GitHub Here GitHub - C360NavigationBar
If you're backward supporting iOS6 do a check on the root view controller as such:
PatientListTableViewController *frontViewController = [[PatientListTableViewController alloc] init];
UINavigationController *navViewController = [[UINavigationController alloc] initWithNavigationBarClass:[C360NavigationBar class] toolbarClass:nil];
if ([navViewController.view respondsToSelector:#selector(setTintColor:)]) {
//iOS7
[navViewController.view setTintColor:self.navBarTintColor];
[[C360NavigationBar appearance] setItemTintColor:self.navBarItemTintColor];
} else {
//iOS6
[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleBlackOpaque animated:NO];
navViewController.navigationBar.tintColor = self.navBarTintColor;
}
[navViewController pushViewController:frontViewController animated:NO];
self.window.rootViewController = navViewController;
As #bernhard mentioned above it's possible to saturate the bar tint color to get desired navigation bar appearance.
I wrote an BarTintColorOptimizer utility for that kind of adjustment. It optimizes translucent bar tint color to make the bar's actual color match the desired color in iOS 7.x and later. Look at this answer for details.
Frankly speaking, above answers might be right but following trick worked for me with very ease.
// this is complete 100% transparent image
self.imageBlack = [[UIImage imageNamed:#"0102_BlackNavBG"]
resizableImageWithCapInsets:UIEdgeInsetsMake(0, 2, 0, 2)
resizingMode:UIImageResizingModeStretch];
// this is non-transparent but iOS7
// will by default make it transparent (if translucent is set to YES)
self.imageRed = [[UIImage imageNamed:#"0102_RedNavBG"]
resizableImageWithCapInsets:UIEdgeInsetsMake(0, 2, 0, 2)
resizingMode:UIImageResizingModeStretch];
// some navigation controller
[nvCtrLeft.navigationBar setBackgroundImage:self.imageRed
forBarMetrics:UIBarMetricsDefault];
// some another navigation controller
[nvCtrCenter.navigationBar setBackgroundImage:self.imageRed
forBarMetrics:UIBarMetricsDefault];
Here are the images used for self.imageRed and self.imageBlack.
< > black image is in this brackets won't be visible as it is transparent :)
< > red image is in this brackets.
is there a way to use #aprato solution without subclassing UINavigationBar.
In my project my main view is a UIViewController.
the problem is that the navigationController is a readonly property, is there a way to use you class with my project because i can't use : [[UINavigationController alloc] initWithNavigationBarClass:
thanks
An easy way to get the color you want is using
[<NAVIGATION_BAR> setBackgroundImage:<UIIMAGE> forBarPosition:<UIBARPOSITION> barMetrics:<UIBARMETRICS>];
As long as your image has some alpha, the translucency will work and you can set the alpha by changing the image. This was just added in iOS7. The width and height for the image are 640x88px for vertical (add 20 to the 88 if you want it to be underneath the status bar).

How to get transparency in certain areas of UIView subclass with drawRect override

I've got a UIView subclass with drawRect overridden. The drawing code does not fill the whole area of the view; some of it is meant to be transparent. But when it draws onscreen, what should be transparent is black. How do I get it to be properly transparent?
If I set the backgroundColor to [UIColor clearColor], the whole view disappears. If I set it to any other color, the black area changes to that color. Setting opaque to NO has the same effect. If I draw a transparent rectangle at the start of drawRect like below:
[[UIColor clearColor] setFill];
UIRectFill( rect );
...then it goes to black again. I can use another color in the above code and it draws that color. If I make the color I use partially transparent, I can see the black showing through.
UPDATE: It may be relevant that my view has transparency gradients. I tried testing with a really simple UIView subclass that just draws a blue rectangle inside its bounds and leaves everything else transparent. Setting that view to opaque=NO renders as expected.
The view's opaque has to be set to NO and backgroundColor to [UIColor clearColor]. Also, the wrong blend mode was being used. We had:
CGContextSetBlendMode(context, kCGBlendModeSourceAtop);
We needed:
CGContextSetBlendMode(context, kCGBlendModeDestinationOver);
The drawing code was generated by a graphics tool that can output code, and their support department figured out that the wrong blend constant was being generated because of an off-by-one error.
Try using this line of code to initizlize your view.
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
[self setOpaque:NO];
[self.layer setOpaque:NO];
}
return self;
}
and you can set alpha property to make transparent effect
self.alpha=0.3f;

Shadow in separate view from UIImage for dynamic adjustments

I would like to obtain this effect (http://stackoverflow.com/questions/7023271/how-to-adjust-drop-shadow-dynamically-during-an-uiimageview-rotation) but from a more complex image than just a red square ! If the link ever gets broken, it's a about how to adjust drop shadow dynamically during an UIImageView rotation.
So I tried implementing something but I just can't get the shadow in a separate layer... Here is my code, very simple, but doesn't work:
// here is my code
- (void)viewDidLoad {
[super viewDidLoad];
testView = [[UIImageView alloc] initWithImage: [UIImage imageNamed:#"handNoShadow.png"]];
testViewShadow = [[UIView alloc] initWithFrame:testView.frame];
testViewShadow.layer.shadowPath = [[testView layer] shadowPath];
testViewShadow.layer.shadowOpacity = 1.0;
testViewShadow.layer.shadowOffset = CGSizeMake(10, 10);
testViewShadow.layer.shadowRadius = 5.0;
[self.view addSubview:testViewShadow];
[self.view addSubview:testView];
}
PS: i did #import
I do get an image but no shadow... =(
Any lead, help, code, link... is welcome !
Thanks
possible cause:
your testViewShadow.clipToBounds property is set to YES (should be NO)
your testViewShadow do the drawing of the shadow correctly but another UIView is on top and mask it. Check your Z order. Either the order in Storyboard/Nib file (or the order you added the subviews programmatically). Last in the list (or last one added) is on top. For my app I had to put the UIView that need a shadow last so that no other view mask it.

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