The classes provided by Leaves developed by Tom Brow supports single images for each page of the book with flip effect. In one of our projects we need to show multiple images in a single page along with the flip effect. Has anybody done that with 'Leaves' or is there any other alternative?
We need this images to be added separately so that we can use UIImage selected actions as this images are also required to replaced.This view will also have UITextBox and UILabel.
I know that from iOS 5 on wards UIPageViewController is available which can serve this purpose but for this project we need to support iOS4 also so UIPageViewController can be ruled out.
Try to render two images in a graphics context and then extract the image from the context and draw it in pdfcontext. Hope this might help you.
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I am building my first project that is an interactive ebook app for the iPad
I started with the Single View App template from XCode
So far, the project is mostly a series of block animated transitions between UIImageViews and MPMovieController videos, very serial so far
Everything is coded within a single view under a single view - the image views fade in and out with alpha animations
I am beginning to run into memory issues. I've used memory instruments and see that most everything is loaded into memory at the beginning (images from the InterfaceBuilder) aside from some videos instantiated at runtime
My question is - how should I reorganize my code to better utilize memory? Should I separate into different views under one view controller, or have multiple view controllers?
And which might be the most straight forward to implement?
Images are very memory-intensive. So:
Do not load an image until you actually need it (for display). When you are done with it (the image view is no longer visible), release it (by setting that image view's image to nil). Do not maintain the images in an array or anything like that. Do not create the image views preloaded with images in advance in the nib.
When you actually need an image for display, load it in code using imageWithContentsOfFile:, not imageNamed:. Thus you prevent caching of the image.
It is a waste of memory to work with an image larger than the display size. If these images are large, you can save a lot of memory up front if you load the image at the actual size needed for display. This is easy to do with Image IO framework and CGImageSourceCreateThumbnailAtIndex.
I think you need to use multiple view controllers and separate your code in small separated views and objescts that controll you app flow..
On the one hand it's better to have multiple views and so on..but it's a pain to rewrite code you worked on (unless it's absolutely necessary).
In my opinion if you don't have anything unnecessary in memory (i.e. when you take a view off screen you release the memory it used) you don't need to do anything.
After all, even if you split the code as it should have been, if your memory management is good, it will take the exact same memory.
You should be able to do this with a single view controller:
Load your images lazily from code. Keep an array of the image names rather than the images themselves, and load them just before you need them.
Make sure your images aren't larger than they need to be.
Recycle your image views. If the user won't see more than two image views at a time (including both the from and to in a transition), you should only have two image views.
Don't worry about whether the images are cached; iOS's caches are designed to release their contents under stress. That said, do not implement your own caching system. You might not release images properly under stress. If you need caching, use NSCache.
I am working with a small camera app for a client and I have now finished all functionality of it. In the standard camera controls i need to modify one thing , the cancel button should say gallery instead.
But unless i am missing something i will need to remove the overlay by setting showsCameraControls to NO and then building my entire overlayView from scratch.
I have found this solution but I am afraid to go this route due to the warning in the beginning of the post.
So is there any valid way of doing simple small modifications to the existing camera overlay control UI or do you have to build it from scratch if you need to change one tiiiiiiny thing?
Unfortunately, having been in this situation I can safely say you need to build the controls from scratch. You really only have two options: create your own camera overlay, or use the default one.
Now, you could use the techniques described in the link you cite, and iterate through the various subviews and modify them 'blind'. The rather large danger with this is every time Apple change the internal structure of the image picker it could potentially break your solution. So I'd definitely stay clear of it.
I am developing an iPad app that needs to have multiple image sources, on the device/Photo Albums, remote and some included with the app. Now the ideal situation would be to have a UIPopover controller with 3 tabs for each source. The only problem is I can't seem to figure out how to have a UIImagePicker be in its own tab. What I am trying to do is very similar to Apple's Keynote for iPad. The photo icon's popover has tabs and the far left tab called media for sure has a UIImagePicker in there. I have no idea how they did that, is it possible for me to do something like that? I think the main issue is that the Image Picker is it's own navigation controller and it cannot be pushed on to another navigation controller. Any help would be greatly appreciated!
check out this - https://github.com/key1jp/ELCImagePickerController
you can implement it with custom asset library
The built-in image picker is no good.
Create your own image picker and add it to your navigation controller as a normal view. Start from either the Matt Tuzzolo or the MyImagePicker from the WWDC 2010 sample code. Note that you probably want to add image and video preview - I copied the image viewer from MyImagePicker and added a 'add' or 'remove' button to it, and the same for video.
Your image picking is in two steps, one for selecting the group, and one for selecting the assets within the group. I recommend dividing the first step into a two - if there is only one, then go directly to that group, i.e. when you have found the first group, check whether that group was the last (block stop argument). Then push the right view controller.
Obiously modify the size of the thumbnails also, they are iPhone size now. Adding a line of metadata (icon and duration) looks much nicer and is more informative for video.
I also recommend adding a 'click-and-hold' function for extended information after like 2 seconds.
Handle different sources by creating a protocol which gives you what you want, i.e.
-(BOOL)isImageAtIndex:(NSInteger)index;
-(UIImage*)thumbnailForUndex:(NSInteger)index;
-(void)setSelectedAtIndex:(NSInteger)index;
Creating a source which handles local files, included resources and assets is perfectly possible - I use NSURLs and check on the url scheme.
Are you not using UITabBarController for your tabs? You should be able to add a UIImagePickerController directly to viewControllers. I'm not sure whether that is a supported use of the image picker, though; the documentation only mentions displaying it modally or displaying it in a UIPopoverController.
It's not usually useful to look at an Apple app to find out what you can do with various built-in controls, as Apple allows themselves to use private APIs.
I'd need to create a iPad-app which would be rendering multiple PDF-Files (one file contains one page).
Each page should be scrollable, zoomable and if the user taps on a part of the PDF a website or photo gallery should popup.
Currently i think i could do that either with:
A. UIWebView
Displays the pdf's nicely, scrolling and zooming works. But it looks like a lot of trouble to realize the clickable parts of the PDF.
I don't know if i could use CGPDFContextSetURLForRect
Getting the touch-events from UIWebView to do something like CGPDFContextSetURLForRect my self looks like it would be some "quite bad" hack. See: http://github.com/psychs/iphone-samples/blob/master/WebViewTappingHack/Classes/PSWebView.m
B. Quartz
I found some resources describing how to display PDF's directly via Quartz.
See:http://developer.apple.com/iphone/library/documentation/GraphicsImaging/Conceptual/drawingwithquartz2d/dq_pdf/dq_pdf.html
This would allow using CGPDFContextSetURLForRect
But i have no idea if this would - like UIWebView - support scrolling and zooming out of the box?
Anybody could enlighten me on this please?
Thanks for your time!
[Edit: changed 3.0 to 3.2]
[Edit: my "solution"]
Hi!
I could come up with a working implementation for PNG but not for PDF's.
[Abstract]
My sollution was Rendering the content, intercepting the touches on it, retreiving the coordinates relative to the displayed content if it is one touch and finally looking up what to do from a mapping containing the interactive areas as coordinates and what to do if they get clicked.
[For PNG]
It was way more cumbersome to implement somethink like that than i would have imagined...
And the implementation i got working depends heavily on the content you want to display because this does work for UIImageView but i could not get it working with UIWebView.
First you need a UIScrollView and UIImageView to render the content and support scrolling/zooming.
Then you need to implement some handling to get the touches/gestures you are interested in.
See: developer.apple.com/iphone/library/samplecode/ScrollViewSuite/Listings/1_TapToZoom_Classes_TapDetectingImageView_h.html
This sample from apple provides everything you need to get this part working.
As a bonus it also takes care about transforming the coordinates relative to the viewport of the content which is very handy! (else you would only know where the tap happend on the screen wich only one half of the info you need if your content is zoom-/scrollable)
[For PDF]
If you want to do this with PDF the first thing would be that you need to use a UIWebView (probably you could do it via Quartz or something else too)
Getting the touches with a UIWebView is a real pain!
There are a lot of ways proposed on the web and besides one noone did what it should do.
After days of googling i found this gem: cocoawithlove.com/2009/05/intercepting-status-bar-touches-on.html
So... subclassing UIWebView does not get you anywhere unlike UIImageView and you have to subclass UIApplicationMain and implement its method for handling touch-events.
Here you could reuse some of the "Touch-Handling-Stuff" from the apple-examlpe from above.
Now you would need to translate the coordinates of the touch to your content if it is zoom-/scrollable. UIWebView DOES NOT do this for you unlike UIImageView!
I could never figure out how to get the required information(what part of the content at which zoomlevel) from a UIWebView to translate the coordinates but due to the changed requirements from PDF to PNG i didn't care to get it working too much.
hope this helps.
Using the CGPDF* operators will allow you to write a UIPDFView, which operates exactly as UIImageView but uses a PDF as the source image. Create your own custom subclass of UIView and implement drawRect: to, eventually, call CGContextDrawPDFPage. Based on a quick Google search (because I know the keywords), this page seems to explain that side of things quite well.
You can then directly substitute your custom UIView subclass for the UIImageView and proceed exactly as you have with the PNG solution.
What would be the best approach to make one page flip like a real magazine? Like I put the finger in the corner of the screen then flip the page, as in this video.
Is it a sequence of images? All images are in one View or Imageview? Or there is another way to do it using the some stuff of the SDK? Does this effect exist, or would I have to write it?
This would fix your magazine problem... https://github.com/ole/leaves/tree/twopages
If it was me i'd try to use the API that someone has provided, save yourself some trouble:
CodeFlakes PaperTouch API
That's just a sequence of images as the backgrounds, and the "text" scales horizontally narrower.
For detail implementation you need to ask the original developer.
UIPageViewController is a new class in iOS 5 that you might be interested in if you don't have to support older iOS versions.
(before someone warns me about NDA, note that this class was announced publicly on one of wwdc keynote slides, I'm just giving a link to docs which can only be accessed by iOS Developer Program members)