I need to create button like this
and the change the background programmatically like this
and like this
I can not use images for different states of a button because each time I have different text on it.
What to start from ? I tried to understand CoreGraphics and CoreAnimation but there is too small amount of examples and tutorials so my attempts didn't give me any success.
You can, and should, use an image for this. UIKit has a method resizableImageWithCapInsets that creates resizable images. You feed it a minimum sized image and the system stretches it to fit the desired size. It looks like your image is fixed in height, which is good since you can't do smooth gradients with this technique.
UIButtons are composed of a background image and title text, so you can use an image for the background shapes (setBackgroundImage(_:forState:)), and then change the text using setTitle(_:forState:).
However, you can still use Core Graphics for this, and there are benefits to doing so, such as the fact that it reduces the number of rendered assets in your app bundle. For this, probably the best approach is to create a CAShapeLayer with a path constructed from a UIBezierPath, and then render it into a graphics context. From this context, you can pull out a UIImage instance, and treat it just the same as an image loaded from a JPEG or PNG asset (that is, set it as the buttons background image using setBackgroundImage(_:forState:)).
Related
I'm trying to create an iOS recoloring app (this is my reference), and i need to know how recolor some portion of the image when user taps on a given area. All the loaded pictures will be black/white initially.
Is there any prebuilt library? Or which graphics framework should i use?
Any help will be appreciated.
If what you are looking for is adding/replacing the colour within a certain shape and edges are really important (as in the example) then you should be looking into vectorised drawing.
What this means is every shape in your image would have an actual object representation in your code, and you could easily interact with that object to do whatever you want (i.e. tap gestures to change colour, zoom etc.).
This however, means that you can't simply use .jpeg images, and you need to use images in vector format, such as .svg or CorelDraw.
As a reference, check out SVGKit, which is an excellent library for working with SVG images.
Frosted Glass Effect
I'm thinking of how to approach this logically..
So we take the background image ( for example )
Then, we want to add our frosted glass button to this image. Here's how it should look..
Now I know I cannot programatically blur the background image of the button, so I'll to try and do it with two images.. Background.png and Backgorund_Blurred.png.
Now, the frosted glass effect will happen on animated objects. So, as they move across the screen, it should appear that it is blurring the background image behind it, however, to achieve this I can only think of one way. But doing so is beyond my current capability.
It would have to be a background_blurred image for the UIButton for example. No scaled in any way, and the exact same size as the normal background. Then, I would have to take the buttons relative position on the normal background and append the background_blurred of the button to suit.
My first question; is this possible?
Second question; is there an easier approach?
Lastly, I've added an image to make sense of the relative position theory.
Check out the FXBlur library, it'll let you blur images/views.. I've used it successfully and sounds like it'll do what you want.
I think having two images for these assets maybe easier, but having the views blur may be better in the long run as you wouldn't have to worry about updating the images for different resolutions in the future or care about how big the button is/will be.. Also if you want to do this with more images it'll turn into a mess with all the different images to manage.. The library is simple to use, with one call you'll have a blurred image/view..
Hello: Currently in my project, I'm using OBShapedButton to process touches on a lot of objects that overlap (it's a map with each territory its own separate object). Basically, this library prevents a touch from being processed on a transparent point on the given view.
I'm attempting to add a border effect to just the edges of the opaque part of the UIImage (and adding a semi-transparent overlay above that). Something to the effect of this:
Which can be simplified to this (example of one image):
I am currently using MGImageUtilities to color in the opaque parts of territories using this line:
[territory setImage:[[territory image] imageTintedWithColor:tint]];
The problem is that I'm not sure how to just color the borders (which can be any shape). I've looked at this link already, but haven't been able to come up with anything.
Thanks in advance for the help!
Terribly hacky, but use MGImageUtilities' UIImage+ProportionalFill with scale resizing to create a slightly larger image, UIImage+Tint to red, and stack below.
The library you are using doesn't actually specify a shape layer. It uses alpha values from the PNGs that you give it.
Could you use a different 'highlighted' or 'selected' PNG that adds the border effect you are looking for?
Otherwise, it you will have to generate a UIBezierPath from your PNG image, which sounds like a very computationally intensive operation. At that point, I might question whether this library meets your needs.
I have a viewController with a UIImageView. The imageView is to be loaded with a different random picture from a given array when the viewController is displayed. Above the UIImageView I would like to implement a filter similar to one I found in photoshop but with my own custom modification for a clear window to the image below. Basically, what I am looking to do is display a random image behind a blurred filter but I would like a part of the blur filter to have a custom shaped window to the image below it where the image can be seen clearly. The rest of the image would still be blurred out. I have read apples documentation for applying filters to images but none of them suit my needs. Pretty new to development and haven't written any code for this feature yet. I'm more looking to see if it can be done and if so, could you point me in the direction of where I can research to find the answers I'm looking for? cheers!
I would recommend that you take the input image, pass it through a CIGaussianBlur, then I'd draw the image applying an image mask (using CIBlendWithMask or a CGPath.)
I'm considering building an app that would make heavy use of a flood fill / paint bucket feature. The images I'd be coloring are simply like coloring book pages; white background, black borders. I'm debating which is better to use UIImage (by manipulating pixel data) or drawing the images with Core Graphics and changing the fill color on touch.
With UIImage, I'm unable to account for retina images properly; it destroys the image when I write the context into a new UIImage, but I can probably figure out. I open to tips though...
With CoreGraphics, I have no idea how to calculate which shape to fill when a user touches an area and then actually filling that area. I've looked but I have not turned up a successful search.
Overall, I believe the optimal solution is using CoreGraphics, since it'll be lighter overall and I won't have to keep several copies of the same image for different sizes.
Thoughts? Go easy on me! It's my first app and first SO question ;)
I'd suggest using Core Graphics.
Instead of images, define the shapes using CGPath or NSBezierPath, and use Core Graphics to stroke and/or fill the shapes. Filling shapes is then as easy as switching drawing mode from just stroking to stroking and filling.
Creating even more complex shapes is made much easier with the "PaintCode" app (which lets you draw and creates the path code for you).
As your first app, I would suggest something with a little less custom graphics fiddling, though.