I have an image that I would like to display in a UITableViewCell using the UITableViewCellStyleSubtitle style that provides a UIImageView, and two lines of text, plus an optional accessory view.
However, when I set the content mode of the UIImageView to either of UIViewContentModeScaleAspectFit or UIViewContentModeScaleAspectFill, it appears to make no difference. Both of these content modes simply display the entire image, shifting the text to the right to make room for the image.
Does anyone have any examples of how these actually differ in practice? The docs say:
UIViewContentModeScaleAspectFit:
Scales the content to fit the size of the view by maintaining the aspect ratio. Any remaining area of the view’s bounds is transparent.
UIViewContentModeScaleAspectFill:
Scales the content to fill the size of the view. Some portion of the content may be clipped to fill the view’s bounds.
But these content modes don't appear to be behaving as advertised.
EDIT: I'm running SDK iOS 4.
I had the same problem.
Seems like the Apple documentation is a bit lacking.
I found the answer by searching around the internet.
http://www.iphonedevsdk.com/forum/iphone-sdk-development/2973-crop-image.html
Basically,
img1.contentMode = UIViewContentModeScaleAspectFill;
img1.clipsToBounds = YES;
If you want it to be a bit more fancy, check out this post:
UIImageView change Width and Height
The reason you don't see a difference between those modes is that the UITableViewCell automatically sizes its image view to fit the aspect ratio of the image. The content modes only come into play when the view's aspect ratio is different from the image's.
Either override layoutSubviews in your custom UITableViewCell class or create an image view yourself (don't use the one that the table view cell provides).
Related
I have an almost complete app. I want to use auto layout but even though I have searched a lot about this subject I could not find an answer that I could use. I can get it to show correctly on one screen size but not on another... Here is my question
How do I put the necessary constraints so that even if the counter is scaled for the different sized devices,the label and the button are at the same place on the image? (the image is a png image)
I would really be glad if you can answer or direct me to an answer that shows how to do a similar thing.
This is what I want
And this is what happens if I try doing it with auto layout and on a different screen size.
This is not the same image that I am using in my app but it will give you an idea.)
Thanks again
Edit:
Thanks for the answers but as pointed out in the comments, 1st answer does not provide a way to scale the image for different screen sizes.
Second answer provides a way but I could not understand the 2nd part of the answer.I need a little bit more detail. I would be glad if there is anyone out there who can help me on this issue.
I am still struggling with this issue. If I follow the 2nd answer Xcode says I need X position,width for the first filler view and Y position,height for the 2nd filler view.I am stuck at this point. I am not sure what value to give to these views.
You have to add constraints with respect to the image view. I have created a small project with your image. This should help you get started.
https://1drv.ms/u/s!Aq8sK_MQLIL9gxMl-lBOMHkToudU
Because the image size will change on different screen sizes, you can't set constant constraints. What you need is proportional constraints.
Set your UILabel and UIButton to have the width and height proportional to the UIImageView width and height respectively.
To do that: Click on your UILabel
and Ctrl Drag it over the UIImageView, selecting Equal Widths and Equal Heights.
Let's say your UILabel has a width of 100px and your UIImageView has a width of 500px. Edit the constraints that you have just set, and set the multiplier to be 100:500
This will make sure that any modifications on the UIImageView width, will affect the UILabel width accordingly. Do the same for height constraint.
Repeat same steps for UIButton.
The top/bottom/trailing/leading constraint cannot be set proportional to the UIImageView size unfortunately, but you can have filler views - transparent views that can mimic the layout constraints.
You will need two filler views: one for top constraint:
(set its height to be proportional to the UIImageView height)
and one for leading constraint
(set its width to be proportional to the UIImageView width)
I can make a small video for you if this is not clear enough.
I've got a UIImageView that takes up the whole cell and shows an image. I'd like to blur the bottom third of the view in the iOS7 style (we're targeting iOS7). There will be a label over the blurred part.
The issue seems to be that I can't "screenshot" the UIImageView right as I am setting up the cell in tableView:cellForRowAtIndexPath: as it hasn't loaded yet. Although i've even tried setting up a timer for a 0.1 second delay and that also doesn't work.
I've tried the stuff on http://damir.me/posts/ios7-blurring-techniques
I've tried https://github.com/justinmfischer/7blur
I'd like to use the new screenshotting API drawViewHierarchyInRect:afterScreenUpdates:
I'd also like to use apple's sample code UIImage+ImageEffects
The only thing that has worked so far has been to just put a UIToolbar in but the performance is really slow. I don't need dynamic updates.
I've managed to get the following effect a few times but it has just tinted the view and hasn't actually blurred anything so I'm a bit confused.
Use UIImageEffects sample from apple
Make a Image View with a size of the lower portion you want to blur... and then set its image to a blurred one. also set its content mode to UIViewContentModeBottom for the proper clipping
Since your image isnt the size of the cell.. first get a temp image as it is being displayed in the cell by drawing a UIImage from it.. refer for the code here
How to capture UIView to UIImage without loss of quality on retina display
then blur that image
Load this image into a UIImage, blur the image, clip to fit the area that you want. Use UIImage+blur.h
I have an iOS app which boils down to the following:
A view controller which implements all the UIScrollViewDelegate methods.
A customised UIImageView which is the view returned by viewForZoomingInScrollView in the first view controller.
In the drawRect method of the customised UIImageView I overlay some text at various positions on the image, the text can be at various sizes and angles, constrained by a rectangle defined by points on the image. So the co-ordinate system is all relative to the image associated with the UIImageView.
Sometimes the text is having to be rendered into areas that are far too small to allow the text to be readable at the default zoom level.
When I zoom in, however, this doesn't make the text any more readable as the text was rendered on the original UIImageView at the font size appropriate for the bounds it was given.
What I'd like is some way to redraw this text, in the correct location still, at a proportionally larger font size when zoomed in. Is this possible, and how would I do it?
I've been working on a zoomable floorplan myself and dealt with it in a rather simple way.
I put my text in labels and put those labels on top of the ImageView.
While zooming the labels scale with the UIImageView and thus the text within scale as well.
When zooming in too much however text becomes vague and blurry so you might want to update those text labels in the:
- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(float)scale
For me this was sufficient, I hope this might be so for you as well.
Instead of trying to fix this, I'd say your design is a bit wrong. I'd reengineer this so that you're rendering the entire contents that you're displaying in the highest zoom that you want, and then allow the scrollview to zoom in/out of the finished content by specifying the zoom parameters. Otherwise you'll go insane trying to fix text. Just draw the entire image / document as big as you want it to be, then add THOSE contents to the scroll view, at some lower zoom, allowing the user to zoom in/out as they desire. Then you're done.
You can write your overlay text on UILabels, attached to the UIViewController view.
Then you need to make your own custom class from UIScrollView and override
- (void)setContentOffset:(CGPoint)anOffset
here, using the anOffset and self.zoomScale you can place your labels at the places you want, with apropriate font size and all. So, they will change their positions every time your scrollview moves or zooms.
I want to add a logo to the navigation bar on the first view controller, but it scales it badly because I don't know what the maximum size is. Does anyone know?
By the way, I know about the trick for creating full-sized images but I don't want to do that, I just want to utilise the built-in titleView property.
Thanks!
In general, I think that the title view is adjusted to whatever space other views leave left and right. At least that is the behavior of the standard title view.
Have you tried to play with the contentMode property of your UIImageView (which I assume you put into the titleView)? If not, try
imageView.contentMode = UIViewContentModeScaleAspectFit;
and try out a suitable CGRect for the frame. If your image is just large enough for the smallest title view, it should work no matter how wide the title view gets.
I have a subview inside a uiscrollview. Then I zoom it out. So it becomes bigger and allows me to scroll through it.
So what is actually changing here? ContentSize of UIScrollView?
If you are not manually responding to changes in the zoom scale (like I describe in this answer), the view that you return from the -viewForZoomingInScrollView: delegate method is simply having a scaling transform applied to it by the UIScrollView. The frame size of the view is not changing, it is just being graphically transformed (which is why you see blurriness at higher scale factors).
The content size of the scrollview remains logically the same. If you check the frame of the scroll view it remains the same.
I think all that is changing is the scaling of the CGLayers. When you zoom in, it shrinks the clipping region frame smaller but then scales the CGLayer transform upwards. In other words, all the logical elements are still present it is simply choosing to draw and display a different part of it.
In the iPhone Application Programming Guide they have a good explanation about the relationship between frames, clipping regions and various transforms on views.