I have a UIViewController that implements a UIScrollView with the UIScrollViewDelegate. Attached to it is an UIImageView for which the user must crop the photo via zooming it and panning to fill the entire length of the screen. After the user has finished cropping and they hit done, the original UIImage gets sent to the next UIViewController.
I'm wondering, is there anyway, using the original image, to display it in a UIScrollView and allow the user to zoom and pan it so ONLY the cropped area gets shown? IE none of the image that was outside of the cropped area gets shown in zooming and panning? Is there a way to do this without explicitly cropping the image?
This might head you in the right direction: Displaying part of an image
Not to sure if this will work with the way you are displaying it. But if it does it could be a simple solution. You can also read through UIScrollviews and maybe use panGestureRecognizer and pinchGestureRecognizer to limit the area they can zoom and pan.
Set the content size of the UIScrollView to the rect of the cropped area.
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In ViewController I have a big ImageView whose image is captured with a ImagePicker. I want the user to be allowed to zoom in/out the image and then pan it but always inside the ImageView dimensions which must not enlarge, move or dwindle. I have seen I could add a ScrollView to ImageView but I can't figure out how to do that.
Moreover: is it possible to zoom in/out more than one ImageView at a time? I mean I have some smaller imageViews floating upon a bigger imageView. Is it possible to zoom everything all together?
There are plenty of excellent scrollview demo's around.
These will show you where and how to add override functions to implement what you need...
If you have different UIImage Views you can set the zoom programmatically to match the image being "zoomed" ... try experimenting with [UIImage].zoomScale. and the image offset. Its going to get complicated if they are different sizes as you will have to take account of scale when mirroring offset and zoom changes.
I have to show in zoom of a selected area of image continuously. Means if you are changing position simultaneously zoom also to be change. I don't know how to implement this.
UIScrollView has a great method - zoomToRect:animated: - that allows you to zoom on a specific rect. If you have a UIImageView sitting on a UIScrollView then you can zoom around the image view using this one simple method.
In my App I have a full-screen UIScrollView where the content is a UIImageView containing a map image which is about 2000px square (i.e. larger than the UIScrollView).
Currently, I plot a path across the map and animate a "beacon" image along it using a CAKeyFrameAnimation, which works great.
What I would like to be able to do is to make the UIScrollView content move with the animation in such a way as to keep the beacon image in the centre of the screen (giving the user the impression of tracking along the path).
Any suggestions on how I might achieve this?
I want to take an image from the UIImagePickerController and put it on a UIImageView that can move based on touch. I'm not sure how to get the picture onto the UIImageView. I thought the UIImageView automatically resizes the picture, so I couldn't grab just the top half of the picture and put that on the UIImageView. Is there an easy way to do this? thanks!
Use CGImageCreateWithImageInRect to crop (take a segment of?) a picture. Put a UIImageView inside a UIScrollView to let the user scroll through (move based on touch) a large image.
if you want to move and zoom your picture in a view, you need to use a UIScrollView. See Apple's ScrollViewSuite example. If you simply want to position the picture within a UIImageView, set the contentMode of the UIImageView to the setting you want e.g. scale, top, left, etc. See the UIImageView documentation for all options.
I am currently working on an application for a client, and they have made an odd request. The request involves putting a custom image as the indicator for the scrollview. I am not even sure if this is possible but if it is can you please let me know how one would go about doing that.
Thanks
UIScrollView streches a small, semi-transparent circle image to generate its scrollbars. You can find this image as the first subview of a UIScrollView:
UIImageView *circle = [scrollView.subviews objectAtIndex:0];
However, as I said this image is stretched, and as far as I can tell, only the alpha values are considered when drawing the scroll bars.
So for example if you're only interested in changing the top/bottom ends of the scroll bar, you can try to change this image. However, I doubt you'll be able to do anything interesting.
A possible solution that comes to mind, and this is only a theory, is to add a custom, transparent UIView on top of a UIScrollView. Then you can hide the default scroll bar (by using showsHorizontalScrollIndicator and showsVerticalScrollIndicator), pass the necessary touch events to the UIScrollView to scroll the content, and draw the scrollbars in your custom view.