I wanted to draw inner shadow in my drawing. I have drawn a red badge using core graphics and wanted a inner black shadow along the badge boundaries. Please help how to achieve this?
I am attaching my code and the badge image from this:
- (void)drawBadgeInRect:(CGRect)iRect {
UIColor *badgeColor = [UIColor colorWithRed:202.0/255.0 green:19.0/255.0 blue:33.0/255.0 alpha:1.0];
// Drawing the badge
CGContextRef aContext = UIGraphicsGetCurrentContext();
CGContextSaveGState(aContext);
CGFloat aBadgeWidth = 16.0;
CGFloat aBadgeHeight = 16.0;
CGFloat aTextWidth = [self.badge.text sizeWithFont:[UIFont boldSystemFontOfSize:12.0]].width + 7.0f;
if (self.badge.text.length > 1) {
aBadgeWidth = aTextWidth;
}
CGFloat aMaxX = CGRectGetMaxX(iRect) - 1.0 + 50;
CGFloat aMinY = CGRectGetMinY(iRect) + 0.5 - 50;
CGFloat aMaxY = aMinY + aBadgeHeight;
CGFloat aMinX = aMaxX - aBadgeWidth;
CGSize myShadowOffset = CGSizeMake (-50, 50);
CGFloat myColorValues[] = {1, 0, 0, 1};
CGColorRef myColor;
CGColorSpaceRef myColorSpace;
myColorSpace = CGColorSpaceCreateDeviceRGB ();
myColor = CGColorCreate (myColorSpace, myColorValues);
CGContextSetShadowWithColor (aContext, myShadowOffset, 1, badgeColor.CGColor);
CGContextBeginPath(aContext);
CGContextMoveToPoint(aContext, aMinX, aMinY);
CGContextAddArcToPoint(aContext, aMinX, aMaxY, aMaxX, aMaxY, 15.0);
CGContextAddLineToPoint(aContext, aMaxX, aMaxY);
CGContextAddLineToPoint(aContext, aMaxX, aMinY);
CGContextAddLineToPoint(aContext, aMaxX - aBadgeWidth, aMinY);
CGContextClosePath(aContext);
CGContextFillPath(aContext);
CGColorRelease (myColor);
CGColorSpaceRelease (myColorSpace);
CGContextRestoreGState(aContext);
}
Related
How can I draw dots in semi circular pattern in iphone programmatically?
I did using the below code
CGContextRef ctx = UIGraphicsGetCurrentContext();
float angle = 0;
float centerX = self.frame.size.width/2;
float centerY = self.frame.size.width/2;
float startX = 0.0;
float startY = 0.0;
for (int i = 0; i < 8 ; i++) {
startX = centerX + cos(angle) * (radius + 50) - 5 ;
startY = centerY + sin(angle) * (radius + 50 ) - 5;
CGContextFillEllipseInRect(ctx, CGRectMake(startX, startY, 5, 5));
[[UIColor blackColor] setStroke];
angle-= M_PI/7;
}
you can like this way Quartz_2D:-
- (void)drawRect:(CGRect)rect {
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetLineWidth(context, 20.0);
CGContextSetStrokeColorWithColor(context,
[UIColor blueColor].CGColor);
CGFloat dashArray[] = {2,6,4,2};
CGContextSetLineDash(context, 3, dashArray, 4);
CGContextMoveToPoint(context, 10, 200);
CGContextAddQuadCurveToPoint(context, 150, 10, 300, 200);
CGContextStrokePath(context);
}
check out bellow all drawing examples :-
http://www.techotopia.com/index.php/An_iOS_5_iPhone_Graphics_Drawing_Tutorial_using_Quartz_2D
I am trying to draw an image like below with libraries in iOS; but i couldn't.
I think it is very easy to draw but i couldn't achieve.
After i accomplish to draw i will place a label over it.
Use this as your drawRect method:
- (void)drawRect:(CGRect)rect
//// General Declarations
CGContextRef context = UIGraphicsGetCurrentContext();
//// Shadow Declarations
UIColor* shadow = [UIColor blackColor];
CGSize shadowOffset = CGSizeMake(1, 1);
CGFloat shadowBlurRadius = 2;
//// Frames
CGRect frame = rect;
//// Abstracted Graphic Attributes
CGRect shadowBoxRect = CGRectMake(CGRectGetMinX(frame) + 0, CGRectGetMinY(frame) + 0, 40, 40);
CGFloat shadowBoxCornerRadius = 4;
//// ShadowBox Drawing
UIBezierPath* shadowBoxPath = [UIBezierPath bezierPathWithRoundedRect: shadowBoxRect cornerRadius: shadowBoxCornerRadius];
[[UIColor lightGrayColor] setFill];
[shadowBoxPath fill];
////// ShadowBox Inner Shadow
CGRect shadowBoxBorderRect = CGRectInset([shadowBoxPath bounds], -shadowBlurRadius, -shadowBlurRadius);
shadowBoxBorderRect = CGRectOffset(shadowBoxBorderRect, -shadowOffset.width, -shadowOffset.height);
shadowBoxBorderRect = CGRectInset(CGRectUnion(shadowBoxBorderRect, [shadowBoxPath bounds]), -1, -1);
UIBezierPath* shadowBoxNegativePath = [UIBezierPath bezierPathWithRect: shadowBoxBorderRect];
[shadowBoxNegativePath appendPath: shadowBoxPath];
shadowBoxNegativePath.usesEvenOddFillRule = YES;
CGContextSaveGState(context);
{
CGFloat xOffset = shadowOffset.width + round(shadowBoxBorderRect.size.width);
CGFloat yOffset = shadowOffset.height;
CGContextSetShadowWithColor(context,
CGSizeMake(xOffset + copysign(0.1, xOffset), yOffset + copysign(0.1, yOffset)),
shadowBlurRadius,
shadow.CGColor);
[shadowBoxPath addClip];
CGAffineTransform transform = CGAffineTransformMakeTranslation(-round(shadowBoxBorderRect.size.width), 0);
[shadowBoxNegativePath applyTransform: transform];
[[UIColor grayColor] setFill];
[shadowBoxNegativePath fill];
}
CGContextRestoreGState(context);
}
Inner shadows are hard to do with CoreGraphics -- basically, you need to negate your path and draw a drop shadow below it, clipped to your original path.
You can take a look at PaintCode and it will show you the code. It has a 15-min demo mode if you don't want to purchase it, that should be enough for your needs.
You could try this:
#import <QuartzCore/QuartzCore.h>
and in your code , after making the your view set these:
self.layer.cornerRadius = x;
self.layer.masksToBounds = TRUE;
This allows you to have rounded corners on your view. And if you calculate the radius to match your view , you should get the desired look.
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
self.backgroundColor = [UIColor grayColor];
}
return self;
}
- (void)drawRect:(CGRect)rect
{
CGContextRef context =UIGraphicsGetCurrentContext();
CGContextSetRGBStrokeColor(context, 1.0, 1.0, 1.0, 1.0);
// And draw with a blue fill color
CGContextSetRGBFillColor(context, 0.0, 0.0, 1.0, 1.0);
// Draw them with a 2.0 stroke width so they are a bit more visible.
CGContextSetLineWidth(context, 2.0);
CGContextAddRect(context, self.bounds);
CGContextStrokePath(context);
// Close the path
CGContextClosePath(context);
// Fill & stroke the path
CGContextDrawPath(context, kCGPathFillStroke);
self.layer.cornerRadius = self.bounds.size.width/12;
self.layer.masksToBounds = TRUE;
}
I think it will be helpful to you.
Try the below code where myView is the UIView to which you want to set the shadow.
myView.layer.cornerRadius = 5.0f;
myView.layer.masksToBounds = YES;
[myView.layer setShadowColor:[[UIColor blackColor] colorWithAlphaComponent: 0.5]];
[myView.layer setShadowOffset:CGSizeMake(0, -1)];
Hope this helps.-
I got a requirements to display a UILabel with background split between two colors, like in this image:
(colors here are black at the bottom and 50% gray at the top - but this is not important). I tried setting the label's background colour to 50% grey in the interface builder and then do this in the code:
CALayer *sl1 = [[[CALayer alloc] init] autorelease];
sl1.frame = CGRectMake(0, lbl.frame.size.height / 2, lbl.frame.size.width, score1.frame.size.height/2);
sl1.backgroundColor = [[UIColor blackColor] CGColor];
[lbl.layer insertSublayer:sl1 atIndex:0];
Unfortunately, this resulted in the black part being drawn over the text, so the label looks like this:
which is, needless to say, is not something I need. So how can I get this background without turning to custom images? The issue is I need to have UILabel's like this in several places, different sizes - so I would need to create multiple versions of the background image.
Any ideas? Thanks.
this works:
UILabel* myLabel = [[UILabel alloc] initWithFrame:CGRectMake(100, 100, 100, 50)];
myLabel.text = #"Ciao";
myLabel.textColor = [UIColor greenColor];
UIGraphicsBeginImageContext(CGSizeMake(100, 50));
CGContextRef context = UIGraphicsGetCurrentContext();
// drawing with a gray fill color
CGContextSetRGBFillColor(context, 0.4, 0.4, 0.4, 1.0);
// Add Filled Rectangle,
CGContextFillRect(context, CGRectMake(0.0, 0.0, 100, 50));
// drawing with a black fill color
CGContextSetRGBFillColor(context, 0., 0., 0., .9);
// Add Filled Rectangle,
CGContextFillRect(context, CGRectMake(0.0, 25, 100, 25));
UIImage* resultingImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
myLabel.backgroundColor = [UIColor colorWithPatternImage:resultingImage];
[self.view addSubview:myLabel];
Use UIColor's +colorWithPatternImage:. Pass in a 1px by the UILabel's height image and it will be "tiled" across the the width of the view.
myLabel.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"label-background.png"]];
first you have to subclass the UILabel and override it's drawRect: method like this for gradient background
- (void)drawRect:(CGRect)rect
{
//////////////GET REFERENCE TO CURRENT GRAPHICS CONTEXT
CGContextRef context = UIGraphicsGetCurrentContext();
//////////////CREATE BASE SHAPE WITH ROUNDED CORNERS FROM BOUNDS
CGRect activeBounds = self.bounds;
CGFloat cornerRadius = 10.0f;
CGFloat inset = 6.5f;
CGFloat originX = activeBounds.origin.x + inset;
CGFloat originY = activeBounds.origin.y + inset;
CGFloat width = activeBounds.size.width - (inset*2.0f);
CGFloat height = activeBounds.size.height - (inset*2.0f);
CGRect bPathFrame = CGRectMake(originX, originY, width, height);
CGPathRef path = [UIBezierPath bezierPathWithRoundedRect:bPathFrame cornerRadius:cornerRadius].CGPath;
//////////////CREATE BASE SHAPE WITH FILL AND SHADOW
CGContextAddPath(context, path);
CGContextSetFillColorWithColor(context, [UIColor colorWithRed:210.0f/255.0f green:210.0f/255.0f blue:210.0f/255.0f alpha:1.0f].CGColor);
CGContextSetShadowWithColor(context, CGSizeMake(0.0f, 1.0f), 6.0f, [UIColor colorWithRed:0.0f/255.0f green:0.0f/255.0f blue:0.0f/255.0f alpha:1.0f].CGColor);
CGContextDrawPath(context, kCGPathFill);
//////////////CLIP STATE
CGContextSaveGState(context); //Save Context State Before Clipping To "path"
CGContextAddPath(context, path);
CGContextClip(context);
//////////////DRAW GRADIENT
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
size_t count = 3;
CGFloat locations[3] = {0.0f, 0.57f, 1.0f};
CGFloat components[12] =
{ 0.0f/255.0f, 0.0f/255.0f, 0.0f/255.0f, 1.0f, //1
5.0f/255.0f, 5.0f/255.0f, 5.0f/255.0f, 1.0f, //2
10.0f/255.0f, 10.0f/255.0f, 10.0f/255.0f, 1.0f}; //3
CGGradientRef gradient = CGGradientCreateWithColorComponents(colorSpace, components, locations, count);
CGPoint startPoint = CGPointMake(activeBounds.size.width * 0.5f, 0.0f);
CGPoint endPoint = CGPointMake(activeBounds.size.width * 0.5f, activeBounds.size.height);
CGContextDrawLinearGradient(context, gradient, startPoint, endPoint, 0);
CGColorSpaceRelease(colorSpace);
CGGradientRelease(gradient);
}
This will draw black to white gradient background
May this will help you
Happy Codding :)
the above code is from this site http://mobile.tutsplus.com/tutorials/iphone/ios-sdk-uialertview-custom-graphics/
In my iPhone app, I'd like to alter the headers on my UITableView. How can I keep the same gradient/alpha/nice looking style of the gray, default headers, except change the color of it?
If you want to apply a gradient then you could create a custom view class and then override drawRect: and use CoreGraphics to draw a gradient
e.g.
- (void) drawRect:(CGRect)rect
{
CGContextRef currentContext = UIGraphicsGetCurrentContext();
CGGradientRef glossGradient;
CGColorSpaceRef rgbColorspace;
size_t num_locations = 2;
CGFloat locations[2] = { 0.0, 1 };
const CGFloat *startColorComponents = CGColorGetComponents(startColor.CGColor);
const CGFloat *endColorComponents = CGColorGetComponents(endColor.CGColor);
CGFloat components[8] = { startColorComponents[0], startColorComponents[1], startColorComponents[2], startColorComponents[3], // Start color
endColorComponents[0], endColorComponents[1], endColorComponents[2], endColorComponents[3] }; // End color
rgbColorspace = CGColorSpaceCreateDeviceRGB();
glossGradient = CGGradientCreateWithColorComponents(rgbColorspace, components, locations, num_locations);
CGRect currentBounds = self.bounds;
CGPoint topCenter = CGPointMake(CGRectGetMidX(currentBounds), 0.0f);
CGPoint bottomCenter = CGPointMake(CGRectGetMidX(currentBounds), CGRectGetMidY(currentBounds));
CGContextDrawLinearGradient(currentContext, glossGradient, topCenter, bottomCenter, 0);
CGGradientRelease(glossGradient);
CGColorSpaceRelease(rgbColorspace);
}
Then do as per Sachin's suggestion but use your custom view class instead.
you can use this
- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section{
UIView *headerView = [[UIView alloc] initWithFrame:CGRectZero];
headerView.backgroundColor = [UIColor lightGrayColor];
return headerView;
}
I am trying to center an image (with respect to the iphone screen) such that when the view is loaded the image is center width/height... In my case my view is loaded at pixel points 0,0 of the image itself and if I zoom out the image appears in the top left corner as opposed to mid-center of the screen/view. Here is what I have so far:
UIImage *image = [UIImage imageNamed: #"t.bmp"];
self.view.backgroundColor = [UIColor blackColor];
self.mi.frame = CGRectMake(0, 0, image.size.width, image.size.height);
self.mi.contentMode = (UIViewContentModeCenter);
self.mi.backgroundColor = [UIColor blackColor];
[self.mi setImage:image];
/* Draw a line here!!
UIGraphicsBeginImageContext(self.mi.frame.size);
[self.mi.image drawInRect:CGRectMake(0, 0, image.size.width, image.size.height)];
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetStrokeColorWithColor(context, [UIColor redColor].CGColor);
CGContextSetLineWidth(context, 20.0);
CGContextBeginPath(context);
CGContextMoveToPoint(context, 0,0);
CGContextAddLineToPoint(context, 200, 200);
CGContextMoveToPoint(context, 200,0);
CGContextAddLineToPoint(context, 0, 200);
CGContextStrokePath(context);
self.mi.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
*/
self.expimg.maximumZoomScale = 2.0;
self.expimg.minimumZoomScale = 0.1;
self.expimg.clipsToBounds = YES;
self.expimg.delegate = self;
[self.expimg setContentSize:self.mi.frame.size];
[self.expimg addSubview: self.mi];
[self.view addSubview: self.expimg];
Thanks!
Edit: mi is a UIImageView and expimg is a UIScrollView (used interface builder). Also, viewForZoomingInScrollView is defined.
You should be able to do this by adjusting the position and size of the image and scroll view on initial load, and as zoom levels change. Make a method that is called on viewDidLoad, and again on the UIScrollViewDelegate method scrollViewDidZoom:.
Something like this should work (where imageView and scrollView are class attributes):
- (void)centerImage {
CGSize screenSize = CGSizeMake(320, 480);
CGSize imageSize = imageView.frame.size;
imageSize.width = imageSize.width * scrollView.zoomScale;
imageSize.height = imageSize.height * scrollView.zoomScale;
CGSize scrollSize = scrollView.frame.size;
CGFloat centerX;
CGFloat centerY;
CGFloat left;
CGFloat top;
if (imageSize.width > screenSize.width) {
scrollSize.width = imageSize.width;
centerX = imageSize.width/2;
left = 0;
} else {
scrollSize.width = screenSize.width;
centerX = screenSize.width/2;
left = centerX - imageSize.width/2;
}
if (imageSize.height > screenSize.height) {
scrollSize.height = imageSize.height;
centerY = imageSize.height/2;
top = 0;
} else {
scrollSize.height = screenSize.height;
centerY = screenSize.width/2;
top = centerY - imageSize.height/2;
}
CGRect scrollFrame = scrollView.frame;
scrollFrame.size = scrollSize;
scrollView.frame = scrollFrame;
CGRect imageFrame = imageView.frame;
imageFrame.origin = CGPointMake(left, top);
scrollView.contentOffset = CGPointMake(centerX-(imageSize.width/2), centerY-(imageSize.height/2));
}
I have not tested this, so some of my math could be wrong. Either way, it will hopefully give you a good idea of what to do.
Step 1: You create an image view property then init it at viewDidLoad and add to scrollView:
self.pictureImage = [[UIImageView alloc]initWithImage:self.picture];
[_scrollView addSubview:_pictureImage];
self.pictureImage.alpha = 0;
_scrollView.delegate = self;
Step 2: Create adjustZoomScale function to get minimum scale
- (CGFloat)adjustZoomScale{
CGFloat scale = self.scrollView.bounds.size.width / self.pictureImage.bounds.size.width;
CGFloat h = scale * self.pictureImage.bounds.size.height;
if (h > self.scrollView.bounds.size.height) {
scale = self.scrollView.bounds.size.height / self.pictureImage.bounds.size.height;
}
return scale;
}
Step 3: Because frame of scroll view will be updated at viewDidAppear so we need to adjust zoom scale here. And set alpha to make image appear smoother:
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear: animated];
_scrollView.maximumZoomScale = 1.0;
_scrollView.minimumZoomScale = [self adjustZoomScale];
[_scrollView setZoomScale:_scrollView.minimumZoomScale];
self.pictureImage.alpha = 1;
}
Step 4: Implement viewForZoomingInScrollView (scroll delegate method) and return image view
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView{
return self.pictureImage;
}
Step 5: Implement scrollViewDidZoom (scroll delegate method) and adjust point for image view
- (void)scrollViewDidZoom: (UIScrollView*) scrollView {
CGSize boundsSize = scrollView.bounds.size;
CGRect contentsFrame = _pictureImage.frame;
if (contentsFrame.size.width < boundsSize.width) {
contentsFrame.origin.x = (boundsSize.width - contentsFrame.size.width) / 2.0;
} else {
contentsFrame.origin.x = 0.0;
}
if (contentsFrame.size.height < boundsSize.height) {
contentsFrame.origin.y = (boundsSize.height - contentsFrame.size.height) / 2.0;
} else {
contentsFrame.origin.y = 0.0;
}
_pictureImage.frame = contentsFrame;
}
Thank shawhu at this post for point adjusting for image view while zooming
[scrollView zoomToRect:CGRectMake(x, y, width, height) animated:YES]; will work for you...
Where rect should have those center coordinates as origin.