So in my scenario, I have a square that is (for understanding's sake) 100x100 and need to display an image that is 300x800 inside of it.
What I want to do is be able to have the image scale just as it would with UIViewContentMode.ScaleAspectFill so that the width scales properly to 100.
However, after that, I would like to then "move" the image up to the top of the image instead of it putting it inside the imageView right in the center, basically what UIViewContentMode.Top does. However that doesn't scale it first.
Is there anyway to do this type of behavior with the built in tools? Anyway to add multiple contentModes?
I already had a helper function that I wrote that scaled an image to a specific size passed in, so I just wrote a function that calculated the scaled image that would fit into the smaller square I had similar to the size AspectFill would do, and then I wrote code that would crop it with the rectangle size I needed at (0,0).
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I was trying to put an image in UIButton and the image would fill up the space keeping the aspect ratio intact. I was not able to apply the content mode. Please see the screenshot
I also tried from the code and it's not working as well
myButton.imageView?.contentMode = .scaleAspectFill
By changing the alignment, the image takes the whole space but it does not keep the aspect ratio and content mode does not work as well.
What's causing your problem is how small the image is. There are two things you can do. One option is to set the image you have now as the background image and then change the button's constraints to get the proportions right. You won't be able to have the button be the size you have it now, though, because the image will be all stretched out.
The other thing you could do is find a bigger or different image of that symbol (square.and.arrow), rather than using the one already loaded into Xcode.
I have an imageView and say its size is the screen size. It displays an image which has a larger size, and the imageView's content mode is set to scaleAspectFill. Then I drawing some lines on the imageView by using UIBeizerPath.
Later I would like to generate an new image which includes the lines I drew by using drawViewHierarchyInRect. The problem is the new image size is the imageView's size, since the drawViewHierarchyInRect method works only like taking a snapshot. How Can I combine the original image with the lines I drew and at the same time, keep the image's size?
You want to use the method UIGraphicsBeginImageContextWithOptions to create an off-screen context of the desired size. (In your case, the size of the image.)
Then draw your image into the context, draw the lines on top, and extract your composite image from the context. Finally, dispose of the context.
There is tons of sample code online showing how to use UIGraphicsBeginImageContextWithOptions. It's quite easy.
Is there a method on UIImageView that tells me the position of its image within its bounds? Say I have an image of a car, like this:
This image is 600x243, and, where the rear wheel should be, there's a hole which is 118,144,74,74 (x,y,w,h).
I want to let the user see different rear wheel options, and I have a few wheel images to choose from (all square, so they are easily scaled to match the hole in the car).
I wanted to place the car image in a UIImageView whose size is arbitrary based on layout, and I wanted to see the whole car at the natural aspect ratio. So I set the image view's content mode to UIViewContentModeScaleAspectFit, and that worked great.
For example, here's the car in an imageView that is 267x200:
I think doing this scaled the image from w=600 to w=267, or, by a factor of 267/600=0.445, and (I think) that means that the height changed from 200 to 200*0.445=89. And I think it's true that the hole was scaled by that factor, too
But I want to add a UIImageView subview to show the wheel, this is where I get confused. I know the image size, I know the imageView size, and I know the hole frame in terms of the original image size. How do I get the hole frame after the image is scaled?
I've tried something like this:
determine the position of the car image in its UIImageView. That's something like:
float ratio=carImage.width/carImageView.frame.size.width; // 0.445
CGFloat yPos=(carImageView.frame.size.height-carImage.height)/2; // there should be a method for this?
determine the scaled frame of the hole:
CGFloat holeX = ratio*118;
CGFloat holeY = yPos + ratio*144;
CGFloat holeEdge = ratio*74;
CGRect holeRect = CGRectMake(holeX,holeY,holeEdge,holeEdge);
But there must be a better way. These calculations (if they are right) are only right for a car image view that is taller than the car. The code needs to be different if the image view is wider.
I think I can work out the logic for a wider view, but it still might be wrong. For example, that yPos calculation. Do the docs say that, for content mode = AspectFit, the image is centered inside the larger dimension? I don't see that any place.
Please tell me there's a better way, or, if not, is it proven that my idea here will work for arbitrary size images, image views, holes?
Thanks.
The easiest solution (by far) is to simply use the same sizes for both the car image and the wheel option images.
Just give the wheel options a transparent padding (easy to do in nearly every graphics editing program), and overlay them over the car with the same frame.
You may increase your asset sizes by a minuscule amount.. but it'll save you one hell of a headache trying to work out positions and sizings, especially as you're scaling the car image.
I have an image of the UiPopOver
I want to make it bigger or smaller based on the text that i want to display in this. My plan is that i will adda text view inside the image view and scale it accordingly. I am facing difficulty in scaling the image to bigger or smaller.
For example if i know that the text that will fit in it have size of CGSize(80, 100), the how i can scale this image view to a specified size without pixelation.
Any help will be highly appreciated.
you can make the resizable image with the following insets (their positions marked by the colourful lines below), that will do the job for you:
you can find more information about how you can me a resizable image in the UIImage Class Reference, the related method's name is –resizableImageWithCapInsets:.
I'm trying to slice an image in assets Xcode 5. I don't know if what I'm trying to do is possible with slicing.
The image looks like this:
I need to change the width and the height of the image, although not at the same time. The closest I've got is when I use Horizontal for the height and Vertical for the width. The problem is when I change the width, the left side of the image starts as a straight line and the skews and change to the original shape.
I'm about to give up on the idea of slicing and just create three images, left, center and right. Is that the only way to go?
This is how my current slice looks like:
Is there any way to change it so it works at least for the width?
UPDATE
Instead of slicing the image I used a mask and moved the mask.
Slicing works by taking the center section, and stretching it to fill the required space and then putting on the image end caps.
Because your button has a continuous diagonal line you will not be able to slice it. It will stretch the image out like so:
In fact even if you make a centre section and end caps you will still have the same issue as this image can only be scaled.
If you only need a finite set of heights then you should create individual assets for each height that can be sliced horizontally. If you need N heights then you should look into using core graphics to draw your shape in code in a -drawRect: method for arbitrary dimensions.
P.S. if you want to horizontally slice so you can grow the width its most optimal to have only 1 pixel width of image that will be stretched out so your button image resources would look a bit like this:
Aha. TIL: You can change the slicing options from the attributes inspector in the right hand pane in Xcode. To make your slicing work choose only "Horizontal"