Im using the code
NSArray *buttons = [NSArray arrayWithObjects: self.rollBtn,nil];
for(UIButton *btn in buttons)
{
btn.layer.shadowRadius = 3.0;
btn.layer.shadowOffset = CGSizeMake(-2.0, -3.0);
btn.layer.shadowOpacity = 0.5;
btn.layer.shadowColor = [UIColor blackColor].CGColor;
CAGradientLayer *btnGradient = [CAGradientLayer layer];
btnGradient.frame = btn.bounds;
btnGradient.colors = [NSArray arrayWithObjects:
(id)[[UIColor colorWithRed:102.0f / 255.0f green:102.0f / 255.0f blue:102.0f / 255.0f alpha:1.0f] CGColor],
(id)[[UIColor colorWithRed:51.0f / 255.0f green:51.0f / 255.0f blue:51.0f / 255.0f alpha:1.0f] CGColor],
nil];
[btn.layer insertSublayer:btnGradient atIndex:0];
}
But all i get is a button with a drop shadow. I've linked the quartz core library, ive imported it, i've linked the buttons, ive tried using different types of buttons; i'm Stumped.
Any Ideas whats going wrong?
Thanks in advance.
I faced same problem. It seems you are building for iOS6 as I do. I found that Autolayout for storyboards, introduced in iOS6, is causing such problems. Just disable it if you don't use this feature:
Open storyboard in Xcode
Open properties of storyboard (right pane with properties)
Uncheck "Use Autolayout" in "Interface Builder Document" section.
Did you try setting the locations and the start/end points for your gradient ?
btnGradient.locations = #[#(0.), #(1.)];
btnGradient.startPoint = (CGPoint){0., 0.};
btnGradient.endPoint = (CGPoint){0., 1.};
I think you could try to remove any previously existing CAGradientLayer in your button:
for(CALayer* layer in btn.layer.sublayers)
if ([layer isKindOfClass:[CAGradientLayer class]])
[layer removeFromSuperlayer];
and then adding your own.
Related
i have a layer ,i need the top half red shadow
my code is
Shadow.colors = [NSArray arrayWithObjects:
(id)[[[UIColor redColor] colorWithAlphaComponent:0.6] CGColor],
(id)[[UIColor clearColor] CGColor],
nil];
Shadow.startPoint = CGPointMake(0,0.5);
Shadow.endPoint = CGPointMake(1,0.5);
this gives me a left half shadow.
What i have to do to have a top half red shadow
Shadow.startPoint = CGPointMake(0.5,0);
Shadow.endPoint = CGPointMake(0.5,1);
This solved my problem.Thanks borrrden
I am building an universal navigation app on iOS 5.0.
Setting the view backgroundcolor as below looks good for iPhone
self.view.backgroundColor = [UIColor groupTableViewBackgroundColor];
But for iPad, i found out that this does not work as expected.
Is there any alternative to get same background on iPad using some color pattern?
If so ,please point me to some code samples or post some.
Recently when working on an XCode project we had set the background colour to groupTableViewBackgroundColor, which on an iPhone produces a pinstriped background, and works well. This background is the same one as used on UITableViews.
When porting this to iPad, the UITableViews now have a solid grey colour, and groupTableViewBackgroundColor essenitially is the same as [UIColor clearColor].
You would think that grabbing the colour that the UITableView uses would work. I am afraid it does not, as it turns out it is a slight gradient, not so much as you would notice, but when you're changing views, you notice.
The way to fix this is to create a CAGradientLayer, and apply it to a UIView before anything else loads.
First off, you need to create a function that emulates the gradient, below is what I used:
-(CAGradientLayer *)groupGradientColour {
CAGradientLayer *layer = [CAGradientLayer layer];
layer.colors = [NSArray arrayWithObjects:
(id)[[UIColor colorWithRed:(0xE2 / 255.0)
green:(0xE5 / 255.0)
blue:(0xE9 / 255.0)
alpha:1.0] CGColor],
(id)[[UIColor colorWithRed:(0xD0 / 255.0)
green:(0xD2 / 255.0)
blue:(0xD7 / 255.0)
alpha:1.0] CGColor],
nil];
layer.locations = [NSArray arrayWithObjects:
[NSNumber numberWithFloat:0.0f],
[NSNumber numberWithFloat:1.0f],
nil];
return layer;
}
Then call this in viewDidLoad:
UIView *background = [[UIView alloc] init];
background.frame = CGRectMake(
0,
0,
[[UIScreen mainScreen] applicationFrame].size.width,
[[UIScreen mainScreen] applicationFrame].size.height);
CAGradientLayer *gradient = [self groupGradientColour];
gradient.frame = background.bounds;
[background.layer insertSublayer:gradient atIndex:0];
[self.view addView:background atIndex:0];
Once you have done this, you will have a gradient the same style as a UITableView.
This is the code I already have:
CAGradientLayer *gradient = [CAGradientLayer layer];
gradient.frame = backGradient.frame;
gradient.colors = [NSArray arrayWithObjects:(id)[newGradientTop CGColor], (id)[newGradientBottom CGColor], nil];
[backGradient.layer insertSublayer:gradient atIndex:0];
I'm now trying to show a new gradient instead, using the same block of code but different colours going into it. But the new gradient doesn't show, and i think this is because it will not show above the already existing gradient.
How can i fix this?
Use this function (replacing old gradient layer with the new one):
#define kGradientLayerKey #"MyGradientLayer"
void makeViewGradient(UIView *pView,CGColorRef clr1,CGColorRef clr2)
{
CAGradientLayer *gradient = [CAGradientLayer layer];
[gradient setValue:#"1" forKey:kGradientLayerKey];
gradient.frame = pView.bounds;
gradient.colors = [NSArray arrayWithObjects:(id)clr1,(id)clr2,nil];
CALayer *pGradientLayer = nil;
NSArray *ar = pView.layer.sublayers;
for (CALayer *pLayer in ar)
{
if ([pLayer valueForKey:kGradientLayerKey])
{
pGradientLayer = pLayer;
break;
}
}
if (!pGradientLayer) [pView.layer insertSublayer:gradient atIndex:0];
else [pView.layer replaceSublayer:pGradientLayer with:gradient];
pView.backgroundColor = nil;//free memory !
}
Instead of adding additional layers, keep track of your original layer and replace it with your new one. You probably mean to use -replaceSublayer:with: here.
[backGradient.layer insertSublayer:gradient atIndex:0] inserts the new layer at the bottom of the stack, under any other layers. Try
[backGradient.layer addSublayer:gradient] instead.
I have the following code and I can't seem to get it to work.
First I create a view with a layer.
UIView *view = [[[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 100)] autorelease];
CAGradientLayer *gradient = [CAGradientLayer layer];
gradient.frame = view.bounds;
gradient.colors = [NSArray arrayWithObjects:(id)[[UIColor blackColor] CGColor], (id)[[UIColor whiteColor] CGColor], nil];
[view.layer insertSublayer:gradient atIndex:0];
Next I need to replace that layer. I have tried the following and it fails because I don't know how to access that layer 0. At this point I am in a different part of the program so I cannot just call gradient. I need to extricate it from view somehow.
[view.layer replaceSublayer:0 with:newgradient];
Apparently the 0 is supposed to be Old layer but I don't know how to access it.
Thanks.
I think you should be able to use this:
[view.layer replaceSublayer:[[view.layer sublayers] objectAtIndex:0]
with:newGradient];
I'm away from my Xcode development environment and can't test this at the moment though.
Keep a pointer to the gradient layer. If you have alot of them do it with an array.
If you still don't want to do that you can always use this to get an array of all the layers..
[self.layer sublayers];
Then you can cycle through and check some parameter to see if they are the same. Like set the layer.name to something when you create it.
Here is the function :
#define MyGradientLayerName #"MyGradient"
void makeViewGradient(UIView *pView,BOOL bRemoveBackground,CGColorRef clr1,CGColorRef clr2)
{
CAGradientLayer *gradient = [CAGradientLayer layer];
gradient.name = MyGradientLayerName;
gradient.frame = pView.bounds;
gradient.colors = [NSArray arrayWithObjects:(id)clr1,(id)clr2,nil];
CALayer *pGradientLayer = nil;
NSArray *ar = pView.layer.sublayers;
for (CALayer *pLayer in ar)
{
if ([pLayer.name isEqualToString:MyGradientLayerName])
{
pGradientLayer = pLayer;
break;
}
}
if (!pGradientLayer) [pView.layer insertSublayer:gradient atIndex:0];
else [pView.layer replaceSublayer:pGradientLayer with:gradient];
if (bRemoveBackground) pView.backgroundColor = nil;//free memory !
}
I have a custom UITableView cell which has a button and a label. I fire a method when someone taps on the button, and then color that row. It's all working fine.
What I want to actually do is
user taps button, the row is colored in a gradient (it works now)
The gradient fades away
My code is below (BackView is the view in my custom cell)
CAGradientLayer *layer = [CAGradientLayer layer];
layer.frame = BackView.bounds;
UIColor *cOne = [UIColor paleYellowColor];
UIColor *cTwo = [UIColor whiteColor];
NSArray *colors = [NSArray arrayWithObjects:(id)cOne.CGColor,
cTwo.CGColor, nil];
layer.colors = colors;
NSNumber *stopOne = [NSNumber numberWithFloat:0.00];
NSNumber *stopTwo = [NSNumber numberWithFloat:0.8];
NSArray *locations = [NSArray arrayWithObjects:stopOne, stopTwo, nil];
layer.locations = locations;
CABasicAnimation *animateLayer = [CABasicAnimation animationWithKeyPath:#"colors"];
animateLayer.fromValue = [UIColor paleYellowColor];
animateLayer.toValue = [UIColor whiteColor];
animateLayer.duration = 3.0;
animateLayer.removedOnCompletion = YES;
animateLayer.fillMode = kCAFillModeBoth;
animateLayer.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
[layer addAnimation:animateLayer forKey:#"animation"];
[BackView.layer insertSublayer:layer atIndex:0];
With this code, when I touch the button on the row, the background gets a gradient, but it never fades away, there's no animation - nothing. What am I doing wrong? I tried a few permutations and saw some examples, but none that helped me get this working.
Thanks!
When you animate a property with an explicit animation, you have provide the type that property is expecting. The colors property is animatable, however, you are giving it a UIColor for the from and to values. It's expecting an NSArray. Also, you need CGColorRefs for the colors themselves. I haven't tried it, but I'm thinking you need to change your to and from lines to:
animateLayer.fromValue = [NSArray arrayWithObjects:
(id)[[UIColor paleYellowColor] CGColor],
(id)[[UIColor whiteColor] CGColor], nil];
animateLayer.toValue = [NSArray arrayWithObjects:
(id)[[UIColor whiteColor] CGColor],
(id)[[UIColor whiteColor] CGColor], nil];
In theory, this should fade from your yellow/white gradient to white/white which should give the effect of fading out.
Best regards.