I have created myView which is subclass of UIView and drawn a circle on the myView. Now i want to display small images within the circle , not outside of the circle. But i got inside circle and outside circle that means the images are displayed on whole myVIew.
I got like as following picture as
But i would like to get as following as
Is it possible or not? Please help me.
Assuming the ellipse is an UIBezierPath, you can use:
UIImage *patternImage = [UIImage imageNamed:#"thePattern.png"];
UIColor *fillPattern = [UIColor colorWithPatternImage:patternImage];
[fillPattern setFill];
[thePath fill];
EDIT
Fill ellipse created by CGContextAddEllipseInRect using pattern image:
- (void)drawRect:(CGRect)rect {
CGImageRef patternImage = [UIImage imageNamed:#"file"].CGImage;
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextAddEllipseInRect(context, CGRectMake(100, 100, 200, 200));
CGContextClip(context);
CGContextDrawTiledImage(context, CGRectMake(20, 20, 48, 36),patternImage);
}
You could try this:
#import <QuartzCore/QuartzCore.h>
and in your code , after making the circle , add the image and set these:
myImageView.layer.cornerRadius = x;
myImageView.layer.masksToBounds = TRUE;
This allows you to have rounded corners on your image. And if you calculate the radius to match your circle , you should get the desired look.
Hope this helps.
Cheers,
George
Related
Like so:
I know that this will not work with NSShadow, drawing it in drawRect: will work just fine.
You can do this and many other kinds of shadows using Core Animations layers and the shadowPath property. The shadow that you are describing can be make with an elliptical shadow path.
The code to produce this shadow is below. You can tweak the size of the ellipse to have a rounder shape of the shadow. You can also tweak the position, opacity, color and blur radius using the shadow properties on the layer.
self.wantsLayer = YES;
NSView *viewWithRoundShadow = [[NSView alloc] initWithFrame:NSMakeRect(30, 30, 200, 100)];
[self addSubview:viewWithRoundShadow];
CALayer *backingLayer = viewWithRoundShadow.layer;
backingLayer.backgroundColor = [NSColor orangeColor].CGColor;
// Configure shadow
backingLayer.shadowColor = [NSColor blackColor].CGColor;
backingLayer.shadowOffset = CGSizeMake(0, -1.);
backingLayer.shadowRadius = 5.0;
backingLayer.shadowOpacity = 0.75;
CGRect shadowRect = backingLayer.bounds;
CGFloat shadowRectHeight = 25.;
shadowRect.size.height = shadowRectHeight;
// make narrow
shadowRect = CGRectInset(shadowRect, 5, 0);
backingLayer.shadowPath = CGPathCreateWithEllipseInRect(shadowRect, NULL);
Just to show some examples of other shadows than can be created using the same technique; a path like this
will produce a shadow like this
It's far from perfect but I think it does draw the sort of shadow you are looking for. Bear in mind that I have left a plain linear gradient in place from a total black to a clear color. Being so dark, this will not give you a super-realistic shadow unless you tweak the values a bit. You may want to play with the gradient by adding more locations with different alpha values to get whatever stepping you like. Some experimentation is probably required but the values are all there to play with.
As per your suggestion it's a drawRect:(CGRect)rect thing. Just create a custom view and only override it:
- (void)drawRect:(CGRect)rect {
// Get the context
CGContextRef context = UIGraphicsGetCurrentContext();
// Setup the gradient locations. We just want 0 and 1 as in the start and end of the gradient.
CGFloat locations[2] = { 0.0, 1.0 };
// Setup the two colors for the locations. A plain black and a plain black with alpha 0.0 ;-)
CGFloat colors[8] = { 0.0f, 0.0f, 0.0f, 1.0f, // Start color
0.0f, 0.0f, 0.0f, 0.0f }; // End color
// Build the gradient
CGGradientRef gradient = CGGradientCreateWithColorComponents(CGColorSpaceCreateDeviceRGB(),
colors,
locations,
2);
// Load a transformation matrix that will squash the gradient in the current context
CGContextScaleCTM(context,1.0f,0.1f);
// Draw the gradient
CGContextDrawRadialGradient(context, // The context
gradient, // The gradient
CGPointMake(self.bounds.size.width/2,0.0f), // Starting point
0.0f, // Starting redius
CGPointMake(self.bounds.size.width/2,0.0f), // Ending point
self.bounds.size.width/2, // Ending radius
kCGGradientDrawsBeforeStartLocation); // Options
// Release it an pray that everything was well written
CGGradientRelease(gradient);
}
This is how it looks like on my screen...
I simply placed an image just over the shadow but you can easily merge the shadow with an image if you subclass UIImageView and override it's drawRect method.
As you can see, what I did was to simply setup a circular gradient but I loaded a scaling matrix to squash it before drawing it to the context.
If you plan to do anything else in that method, remember that you have the matrix in place and everything you do will be deformed by it. You may want to save the the CTM with CGContextSaveGState() before loading the matrix and then restore the original state with CGContextRestoreGState()
Hope this was what you where looking for.
Cheers.
I could explain how to do this in code, or explain how to use a tool which generate this code for you. I choose the latter.
Using PaintCode (free demo available, 1 hour limit per session).
Draw an oval
Draw a Rectangle which intersects with the bottom of the oval.
CMD click both the rectangle and the oval, in the "Objects" list in the top left corner.
Press the Intersect button in the Toolbar.
Select the Bezier from the Objects list.
Set its Stroke to "No Stroke"
Click the Gradient button (located on the left, below the Selection Inspector)
Press the "+" button
Change the gradient color to light grey.
From the Selection inspector, change the Fill Style to "Gradient"
Select Gradient: Linear
adjust the gradient till you are satisfied.
- (void)viewDidLoad
{
UIImage *natureImage = [UIImage imageNamed:#"nature.jpg"];
CALayer *layer = [CALayer layer];
layer.bounds = CGRectMake(0, 0, 200, 200);
layer.position = CGPointMake(380, 200);
layer.contents = (id)natureImage.CGImage;
layer.shadowOffset = CGSizeMake(0,2);
layer.shadowOpacity = 0.70;
layer.shadowPath = (layer.shadowPath) ? nil : [self bezierPathWithCurvedShadowForRect:layer.bounds].CGPath;
[self.view.layer addSublayer:layer];
}
- (UIBezierPath*)bezierPathWithCurvedShadowForRect:(CGRect)rect {
UIBezierPath *path = [UIBezierPath bezierPath];
CGPoint topLeft = rect.origin;
CGPoint bottomLeft = CGPointMake(0.0, CGRectGetHeight(rect) + offset);
CGPoint bottomMiddle = CGPointMake(CGRectGetWidth(rect)/2, CGRectGetHeight(rect) - curve);
CGPoint bottomRight = CGPointMake(CGRectGetWidth(rect), CGRectGetHeight(rect) + offset);
CGPoint topRight = CGPointMake(CGRectGetWidth(rect), 0.0);
[path moveToPoint:topLeft];
[path addLineToPoint:bottomLeft];
[path addQuadCurveToPoint:bottomRight controlPoint:bottomMiddle];
[path addLineToPoint:topRight];
[path addLineToPoint:topLeft];
[path closePath];
return path;
}
Hope this will help you.
I have a shadow image that I would like to draw around the outer edge of a grouped UITableView section. This is the image:
I can get the UIBezierPath that represents the rect I want to draw around, but I can't figure out how to repeat the image along the route of the rect. So far it just fills the rect with the image:
UIImage *patternImg = [UIImage imageNamed:#"cellShadow"];
UIColor *fill = [UIColor colorWithPatternImage:patternImg];
[fill setFill];
CGRect aSectRect = [self rectForSection:0];
UIBezierPath *aSectPath = [self createRoundedPath:aSectRect];
[aSectPath fill];
Is this possible? What do I need to do?
Unfortunately, there's no way to have UIBezierPath use an image as a "brush" which is essentially what you'd want. But you can have CoreGraphics draw a shadow for you:
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetShadow(context, CGSizeZero, myShadowRadius);
// Draw your shape here
Now if you draw just one shape it will get a shadow. But if you draw more shapes, each will get its own shadow which might not be what you want. The solution is called a transparency layer, which is not related to CALayers or something but is just some kind of "grouping" in CoreGraphics:
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetShadow(context, CGSizeZero, myShadowRadius);
CGContextBeginTransparencyLayer(context, NULL);
// Draw your shapes here.
CGContextEndTransparencyLayer(context);
Between the CGContextBeginTransparencyLayer and CGContextEndTransparencyLayer calls the shadow is disabled. After the CGContextEndTransparencyLayer call, the shadow is applied to everything that has been drawn between begin and end as if it were just one shape.
I'm working on one app where I need to divide a image into two part using a red line.
left part for labels
right part for prices
Question 1.
How can I draw a red line on image?
Question 2.
How can I divide image to two parts using red line ?( red line position is not fixed. user can move the position wherever it want)
Question 3.
How can I get line current position and how can I use that position two divide image
Thanks in advance
I would approach this in somewhat the same manner as koray was suggesting:
1) I am assuming that your above image/view is going to be managed by a view controller, which I will call ImageSeperatorViewController from here on.
Inside of ImageSeperatorViewController, insert koray's code in the -(void) viewDidLoad{} method. Make sure you change the imageToSplit variable to be an UIImageView instead of a plain UIView.
2) Next, I assume that you know how to detect user gestures. You will detect these gestures, and determine if the user has selected the view (i.e. bar in koray's code). Once you have determined if the user has selected bar, just update its origin's X position with the touch position.
CGRect barFrame = bar.frame;
barFrame.origin.x = *X location of the users touch*
bar.frame = barFrame;
3) For cropping, I would not use github.com/bilalmughal/NLImageCropper, it will not do what you need to do.
Try this on for size:
Header:
#interface UIImage (ImageDivider)
- (UIImage*)imageWithDividerAt:(CGFloat)position width:(CGFloat)width color:(UIColor*)color;
- (UIImage*)imageWithDividerAt:(CGFloat)position patternImage:(UIImage*)patternImage;
- (NSArray*)imagesBySlicingAt:(CGFloat)position;
#end
Implementation:
#implementation UIImage (ImageDivider)
- (UIImage*)imageWithDividerAt:(CGFloat)position patternImage:(UIImage*)patternImage
{
//pattern image
UIColor *patternColor = [UIColor colorWithPatternImage:patternImage];
CGFloat width = patternImage.size.width;
//set up context
UIGraphicsBeginImageContext(self.size);
CGContextRef context = UIGraphicsGetCurrentContext();
//draw the existing image into the context
[self drawAtPoint:CGPointZero];
//set the fill color from the pattern image color
CGContextSetFillColorWithColor(context, patternColor.CGColor);
//this is your divider's area
CGRect dividerRect = CGRectMake(position - (width / 2.0f), 0, width, self.size.height);
//the joy of image color patterns being based on 0,0 origin! must set phase
CGContextSetPatternPhase(context, CGSizeMake(dividerRect.origin.x, 0));
//fill the divider rect with the repeating pattern from the image
CGContextFillRect(context, dividerRect);
//get your new image and viola!
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
- (UIImage*)imageWithDividerAt:(CGFloat)position width:(CGFloat)width color:(UIColor *)color
{
//set up context
UIGraphicsBeginImageContext(self.size);
CGContextRef context = UIGraphicsGetCurrentContext();
//draw the existing image into the context
[self drawAtPoint:CGPointZero];
//set the fill color for your divider
CGContextSetFillColorWithColor(context, color.CGColor);
//this is your divider's area
CGRect dividerRect = CGRectMake(position - (width / 2.0f), 0, width, self.size.height);
//fill the divider's rect with the provided color
CGContextFillRect(context, dividerRect);
//get your new image and viola!
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
- (NSArray*)imagesBySlicingAt:(CGFloat)position
{
NSMutableArray *slices = [NSMutableArray array];
//first image
{
//context!
UIGraphicsBeginImageContext(CGSizeMake(position, self.size.height));
//draw the existing image into the context
[self drawAtPoint:CGPointZero];
//get your new image and viola!
[slices addObject:UIGraphicsGetImageFromCurrentImageContext()];
UIGraphicsEndImageContext();
}
//second
{
//context!
UIGraphicsBeginImageContext(CGSizeMake(self.size.width - position, self.size.height));
//draw the existing image into the context
[self drawAtPoint:CGPointMake(-position, 0)];
//get your new image and viola!
[slices addObject:UIGraphicsGetImageFromCurrentImageContext()];
UIGraphicsEndImageContext();
}
return slices;
}
The concept is simple - you want an image with the divider drawn over it. You could just overlay a view, or override drawRect:, or any number of any solutions. I'd rather give you this category. It just uses some quick Core Graphics calls to generate an image with your desired divider, be it pattern image or color, at the specified position. If you want support for horizontal dividers as well, it is rather trivial to modify this as such. Bonus: You can use a tiled image as your divider!
Now to answer your primary question. Using the category is rather self explanatory - just call one of the two methods on your source background to generate one with the divider, and then apply that image rather than the original source image.
Now, the second question is simple - when the divider has been moved, regenerate the image based on the new divider position. This is actually a relatively inefficient way of doing it, but this ought to be lightweight enough for your purposes as well as only being an issue when moving the divider. Premature optimization is just as much a sin.
Third question is also simple - call imagesBySlicingAt: - it will return an array of two images, as generated by slicing through the image at the provided position. Use them as you wish.
This code has been tested to be functional. I strongly suggest that you fiddle around with it, not for any purpose of utility, but to better understand the mechanisms used so that next time, you can be on the answering side of things
For Crop you can try this,
UIImage *image = [UIImage imageNamed:#"yourImage.png"];
CGImageRef tmpImgRef = image.CGImage;
CGImageRef topImgRef = CGImageCreateWithImageInRect(tmpImgRef, CGRectMake(0, 0, image.size.width, image.size.height / 2.0));
UIImage *topImage = [UIImage imageWithCGImage:topImgRef];
CGImageRelease(topImgRef);
CGImageRef bottomImgRef = CGImageCreateWithImageInRect(tmpImgRef, CGRectMake(0, image.size.height / 2.0, image.size.width, image.size.height / 2.0));
UIImage *bottomImage = [UIImage imageWithCGImage:bottomImgRef];
CGImageRelease(bottomImgRef);
hope this can help you, :)
if you want to draw a line you could just use a UIView with red background and make the height the size of your image and the width around 5 pixels.
UIView *imageToSplit; //the image im trying to split using a red bar
CGRect i = imageToSplit.frame;
int x = i.origin.x + i.size.width/2;
int y = i.origin.y;
int width = 5;
int height = i.size.height;
UIView *bar = [[[UIView alloc] initWithFrame:CGRectMake(x, y, width, height)] autorelease];
bar.backgroundColor = [UIColor redColor];
[self.view addSubview:bar];
I was wondering if there is a standard method in iOS to produce the numbered bubble icon for unread messages as the ones used in mail for iphone and mac.
I'm not talking about the red dots on the application item which is done with badgevalue but about the blue bubble beside the mailboxes.
Of course one can do it manually using coregraphics but it's harder to match the dimensions and color of the standard ones used in mail etc.
here are three ways to do this, in order of difficulty..
screen shot your mail app from your iphone, send the image into photoshop, extract the blue dot and use it as an image in your app. To use it in a tableviewcell, you just set the imageView.image = [UIImage imageName:#"blueDot.png"];
same as #1, except save the image as a grayscale, this way you can use Quartz and overlay your own colors on top of it. so you can make that dot any color you want. Very cool stuff.
Use Quartz to draw the whole thing. Its really not that hard. Let me know if you would like some code for that.
OK, twist my arm... here is the code to draw your own gradient sphere... from quartz.
Make a class that inherits from UIView. add the following code
static float RADIANS_PER_DEGREE=0.0174532925;
-(void) drawInContext:(CGContextRef) context
{
// Drawing code
CGFloat radius = self.frame.size.width/2;
CGFloat start = 0 * RADIANS_PER_DEGREE;
CGFloat end = 360 * RADIANS_PER_DEGREE;
CGPoint startPoint = CGPointMake(0, 0);
CGPoint endPoint = CGPointMake(0, self.bounds.size.height);
//define our grayscale gradient.. we will add color later
CGFloat cc[] =
{
.70,.7,.7,1, //r,g,b,a of color1, as a percentage of full on.
.4,.4,.4,1, //r,g,b,a of color2, as a percentage of full on.
};
//set up our gradient
CGGradientRef gradient;
CGColorSpaceRef rgb = CGColorSpaceCreateDeviceRGB();
gradient = CGGradientCreateWithColorComponents(rgb, cc, NULL, sizeof(cc)/(sizeof(cc[0])*4));
CGColorSpaceRelease(rgb);
//draw the gray gradient on the sphere
CGContextSaveGState(context);
CGContextBeginPath(context);
CGContextAddArc(context, self.bounds.size.width/2, self.bounds.size.height/2, radius,start,end , 0);
CGContextClosePath(context);
CGContextClip(context);
CGContextAddRect(context, self.bounds);
CGContextDrawLinearGradient(context, gradient, startPoint, endPoint, kCGGradientDrawsBeforeStartLocation);
CGGradientRelease(gradient);
//now add our primary color. you could refactor this to draw this from a color property
UIColor *color = [UIColor blueColor];
[color setFill];
CGContextSetBlendMode(context, kCGBlendModeColor); // play with the blend mode for difference looks
CGContextAddRect(context, self.bounds); //just add a rect as we are clipped to a sphere
CGContextFillPath(context);
CGContextRestoreGState(context);
}
- (void)drawRect:(CGRect)rect
{
CGContextRef context = UIGraphicsGetCurrentContext();
[self drawInContext:context];
}
If you want to use a graphic resource from iOS, you can find it using the UIKit-Artwork-Extractor tool. Extract everything to the desktop and find the one you want. For example, the red badge for notifications is called SBBadgeBG.png. I don't know which one you mean, so search for it yourself :P
This is what I did to use a badge, the procedure is exactly the same to show a bubble in a subview of your table:
// Badge is an image with 14+1+14 pixels width and 15+1+15 pixels height.
// Setting the caps to 14 and 15 preserves the original size of the sides, so only the pixel in the middle is stretched.
UIImage *image = [UIImage imageNamed:#"badge"];
self.badgeImage = [image stretchableImageWithLeftCapWidth:(image.size.width-1)/2 topCapHeight:(image.size.height-1)/2];
// what size do we need to show 3 digits using the given font?
self.badgeFont = [UIFont fontWithName:#"Helvetica-Bold" size:13.0];
CGSize maxStringSize = [[NSString stringWithString:#"999"] sizeWithFont:self.badgeFont];
// set the annotation frame to the max needed size
self.frame = CGRectMake(0,0,
self.badgeImage.size.width + maxStringSize.width,
self.badgeImage.size.height + maxStringSize.height);
and then override the method drawRect: of your view to paint the badge and the numbers inside:
- (void)drawRect:(CGRect)rect {
// get the string to show and calculate its size
NSString *string = [NSString stringWithFormat:#"%d",self.badgeNumber];
CGSize stringSize = [string sizeWithFont:self.badgeFont];
// paint the image after stretching it enough to acommodate the string
CGSize stretchedSize = CGSizeMake(self.badgeImage.size.width + stringSize.width,
self.badgeImage.size.height);
// -20% lets the text go into the arc of the bubble. There is a weird visual effect without abs.
stretchedSize.width -= abs(stretchedSize.width *.20);
[self.badgeImage drawInRect:CGRectMake(0, 0,
stretchedSize.width,
stretchedSize.height)];
// color of unread messages
[[UIColor yellowColor] set];
// x is the center of the image minus half the width of the string.
// Same thing for y, but 3 pixels less because the image is a bubble plus a 6px shadow underneath.
float height = stretchedSize.height/2 - stringSize.height/2 - 3;
height -= abs(height*.1);
CGRect stringRect = CGRectMake(stretchedSize.width/2 - stringSize.width/2,
height,
stringSize.width,
stringSize.height);
[string drawInRect:stringRect withFont:badgeFont];
}
I like the way this (http://shakeitphoto.com/) application puts a border around the image.. i would like to do something similar in my application but not sure how should I go about doing it.
Any ideas on how given a UIImage can I wrap a frame around it?
From that website, it appears you want a border with a shadow. There's 2 reasonable options, 3 if you don't care about the shadow.
If you don't care about the shadow, you can just do something like
#import <QuartzCore/QuartzCore.h> // this should be at the top
// inside your view layout code
myImageView.layer.borderColor = [UIColor whiteColor].CGColor
myImageView.layer.borderWidth = 5;
This will give you a 5-pixel white border inset into the view, layered on top of the view's contents (e.g. the image). What it won't give you is a shadow. If you want the shadow, there's 2 other options.
You could just create an image that includes the border and the shadow, and nothing else. Just make everything else alpha-transparent. Then you can simply layer this image on top of the one you want to display (either with 2 imageviews, or by creating a third image out of the 2). This should work fine, but it won't scale to different image sizes. In the case of the linked app, the image size is always the same so they could be using this.
The other option is to simply draw the border and shadow on top of your image in a new image. Here's a bit of sample code that will do this - it creates a new image the same size as your original, but with a white, shadowed border:
- (UIImage *)borderedImage:(UIImage *)image {
// the following NO means the new image has an alpha channel
// If you know the source image is fully-opaque, you may want to set that to YES
UIGraphicsBeginImageContextWithOptions(image.size, NO, image.scale);
[image drawAtPoint:CGPointZero];
CGContextRef ctx = UIGraphicsGetCurrentContext();
const CGFloat shadowRadius = 5;
CGContextSetShadowWithColor(ctx, 0, shadowRadius, [UIColor blackColor].CGColor);
[[UIColor whiteColor] set];
CGRect rect = (CGRect){CGPointZero, image.size};
const CGFloat frameWidth = 5;
rect = CGRectInset(rect, frameWidth / 2.0f, frameWidth / 2.0f);
UIBezierPath *path = [UIBezierPath bezierPathWithRect:rect];
path.lineWidth = frameWidth;
[path stroke];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
// note: getting the new image this way throws away the orientation data from the original
// You could create a third image by doing something like
// newImage = [UIImage imageWithCGImage:newImage.CGImage scale:newImage.scale orientation:image.orientation]
// but I am unsure as to how orientation actually affects rendering (if at all)
UIGraphicsEndImageContext();
return newImage;
}
(note: this code has not been compiled and could contain bugs)