I have a method that draws pins by adding an ImageView on top of a slider when a button is pressed. Here is the code:
var loopStartImageView : UIImageView = UIImageView()
func addLoopDrawing(at time: CMTime, for loop: Int) {
let imgHeight : CGFloat = 30
let imgWidth: CGFloat = 30
var pinImg : UIImage = UIImage(named: "pin2x")!
let inset = slider.frame.origin.x
let width = slider.bounds.width
let xPos : CGFloat = CGFloat((Float(time.seconds) / slider.maximumValue)) * width + inset - (imgWidth / 2)
var yPos : CGFloat = slider.frame.origin.y - (slider.frame.height / 2) - 3
let imgV = UIImageView(frame: CGRect(x: xPos, y: yPos, width: imgWidth, height: imgHeight))
imgV.image = pinImg
loopStartImageView = imgV
view.addSubview(loopStartImageView)
view.sendSubviewToBack(loopStartImageView)
}
The drawing is correct when I don't use autolayout to set the position of the slider, but once I do it shows up below the actual positioning.
This method is called in viewDidLoad. My guess is that for some reason the auto layout positioning is not set when viewDidLoad is called.
I was wondering if there is a method that is called once auto layout is fully adjusted?
//
This is what it should look like:
But this is how the view loads (even when calling the addLoopDrawing function inside the viewDidLayoutSubviews)
I was wondering if there is a method that is called once auto layout is fully adjusted?
That would be viewDidLayoutSubviews. That is a very good time to do things that depend upon things having their correct frame, but beware: it can be called many times. The usual thing, therefore, is to implement it along with a Bool property to check that this is the first time.
On the other hand, it might be better not to ask an x-y question like this. The idea of an image view on top of a slider seems wrong. It might be better to describe what you are really trying to do.
Related
This question already has an answer here:
images render larger when loaded programmatically on iPhone X,Xs?
(1 answer)
Closed 1 year ago.
I have an ImageView on my Storyboard layout and I put some images over this ImageView.
To maintain the proportion of the image I created a code to calculate the image scale.
static func getImageScale(_ myImage:UIImageView) -> (width: CGFloat, height: CGFloat) {
let imageViewHeight = myImage.bounds.height
let imageViewWidth = myImage.bounds.width
let imageSize = myImage.image!.size
let myScaledImageHeight = imageViewHeight / imageSize.height
let myScaledImageWidth = imageViewWidth / imageSize.width
return (width: myScaledImageWidth, height: myScaledImageHeight)
}
This is how I use the code above:
ImageMarcasHelper.addScaledImageToScreenWithoutMovement(imageStringName: nome_imagem, scaledImageWidth: percentImageScale.width, scaledImageHeigth: percentImageScale.height, view: view)
Finally, I call this:
static func addScaledImageToScreenWithoutMovement(imageStringName imageNameString:String, scaledImageWidth:CGFloat, scaledImageHeigth:CGFloat, view:UIView) {
var xFinal = 0
var scaledImageWidthMultiplied:CGFloat = 0.0
let vc: UIViewController = view.parentViewController!
let vc_name = type(of: vc)
let image = UIImage(named: imageNameString)
print(image!)
let imageView = UIImageView(image: image!)
imageView.isAccessibilityElement = true
imageView.restorationIdentifier = imageNameString
if vc_name == ResenhaMarcasCabecaController.classForCoder() ||
vc_name == ResenhaMarcasMembrosPosterioresController.classForCoder() {
print("ResenhaMarcasCabecaController view used")
xFinal = Int((image?.size.width)!/1.9)
scaledImageWidthMultiplied = (image?.size.width)! * 1
} else {
// identifica todas as outras views como ResenhaMarcasFocinhoController ou ResenhaMarcasPescocoController ou ResenhaMarcasMembrosAnterioresController
print("viewcontroller genenrica usada")
xFinal = 0
scaledImageWidthMultiplied = (image?.size.width)! * scaledImageWidth
}
imageView.frame = CGRect(
x: xFinal,
y: 0,
width: Int( scaledImageWidthMultiplied ),
height: Int( (image?.size.height)! * scaledImageHeigth )
)
view.addSubview(imageView)
}
On some iPhone models the image resize works perfectly, but on other models it is not calculated correctly.
Check below the images from an iPhone 8 and an iPhone 8 Plus
The red image on the left side is centered, but on the right side the red image is NOT centered.
How can I fix that? There is another code that can I use to fix it or do I need to adapt something on my code?
Or maybe another solution, there is any way to detect the type of screen size or dimension? The same problem happens with iPhone 11 Max and iPhone Max Pro.
The red image is centered on iPhone 11 Max, but is NOT centered on iPhone Max Pro.
--- EDIT ---
#IBOutlet weak var imagemPrincipalCabeca:UIImageView!
I have an IBOutlet that contains the ImageView that I created using Storyboard with AutoLayout and I use the image inside this ImageView to get the scale to apply to other images.
This is the code that I use to get and apply the scale from the IBOutlet that is assigned to the ImageView
let percentImageScale = ImageMarcasHelper.getImageScale(imagemPrincipalCabeca)
ImageMarcasHelper.addScaledImageToScreenWithoutMovement(
imageStringName: nome_imagem,
scaledImageWidth: percentImageScale.width,
scaledImageHeigth: percentImageScale.height,
view: view)
I find out what is the problem.
All calculations are done inside the "viewDidLoad" method. Inside this method, the calculations are not correct because the view still does't know the correct size of the subviews(the container view)
I change all the calculations to be made inside the "viewWillAppear" method. This way I was able to get the correct screen width and height for the subview.
Rather than using a normal button, I subclassed a UIControl because I needed to add a gradient to it. I also have a way to add a shadow and an activity indicator (not visible in the image below) as a stateful button to stop users hammering the button if (for example) an API call is being made.
It was really tricky to try to get the UIControl to rotate, and to be able to do this I added the shadow as a separate view to a container view containing the UIControl so a shadow could be added.
Now the issue is the control does not behave quite like a view on rotation - let me show you a screen grab for context:
This is mid-rotation but is just about visible to the eye - the image shows that the Gradient is 75% of the length of a blue UIView in the image.
https://github.com/stevencurtis/statefulbutton
In order to perform this rotation I remove the shadowview and then change the frame of the gradient frame to its bounds, and this is the problem.
func viewRotated() {
CATransaction.setDisableActions(true)
shadowView!.removeFromSuperview()
shadowView!.frame = self.frame
shadowView!.layer.masksToBounds = false
shadowView!.layer.shadowOffset = CGSize(width: 0, height: 3)
shadowView!.layer.shadowRadius = 3
shadowView!.layer.shadowOpacity = 0.3
shadowView!.layer.shadowPath = UIBezierPath(roundedRect: self.bounds, byRoundingCorners: .allCorners, cornerRadii: CGSize(width: 20, height: 20)).cgPath
shadowView!.layer.shouldRasterize = true
shadowView!.layer.rasterizationScale = UIScreen.main.scale
self.gradientViewLayer.frame = self.bounds
self.selectedViewLayer.frame = self.bounds
CATransaction.commit()
self.insertSubview(shadowView!, at: 0)
}
So this rotation method is called through the parent view controller:
override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
super.viewWillTransition(to: size, with: coordinator)
coordinator.animate(alongsideTransition: { context in
context.viewController(forKey: UITransitionContextViewControllerKey.from)
//inform the loginButton that it is being rotated
self.loginButton.viewRotated()
}, completion: { context in
// can call here when completed the transition
})
}
I know this is the problem, and I guess it is not happening at quite the right time to act the same way as a UIView. Now the issue is that I have tried many things to get this to work, and my best solution (above) is not quite there.
It isn't helpful to suggest to use a UIButton, to use an image for the gradient (please don't suggest using a gradient image as a background for a UIButton, I've tried this) or a third party library. This is my work, it functions but does not work acceptably to me and I want to get it to work as well as a usual view (or at least know why not). I have tried the other solutions above as well, and have gone for my own UIControl. I know I can lock the view if there is an API call, or use other ways to stop the user pressing the button too many times. I'm trying to fix my solution, not invent ways of getting around this issue with CAGradientLayer.
The problem: I need to make a UIControlView with a CAGradientLayer as a background rotate in the same way as a UIView, and not exhibit the issue shown in the image above.
Full Example:
https://github.com/stevencurtis/statefulbutton
Here is working code:
https://gist.github.com/alldne/22d340b36613ae5870b3472fa1c64654
These are my recommendations to your code:
1. A proper place for setting size and the position of sublayers
The size of a view, namely your button, is determined after the layout is done. What you should do is just to set the proper size of sublayers after the layout. So I recommend you to set the size and position of the gradient sublayers in layoutSubviews.
override func layoutSubviews() {
super.layoutSubviews()
let center = CGPoint(x: self.bounds.width / 2, y: self.bounds.height / 2)
selectedViewLayer.bounds = self.bounds
selectedViewLayer.position = center
gradientViewLayer.bounds = self.bounds
gradientViewLayer.position = center
}
2. You don’t need to use an extra view to draw shadow
Remove shadowView and just set the layer properties:
layer.shadowOffset = CGSize(width: 0, height: 3)
layer.shadowRadius = 3
layer.shadowOpacity = 0.3
layer.shadowColor = UIColor.black.cgColor
clipsToBounds = false
If you have to use an extra view to draw shadow, then you can add the view once in init() and set the proper size and position in layoutSubviews or you can just programmatically set auto layout constraints to the superview.
3. Animation duration & timing function
After setting proper sizes, your animation of the gradient layers and the container view doesn’t sync well.
It seems that:
During the rotation transition, coordinator(UIViewControllerTransitionCoordinator) has its own transition duration and easing function.
And the duration and easing function are applied automatically to all the subviews (UIView).
However, those values are not applied to the CALayer without an associated UIView. Consequently, it uses the default timing function and duration of CoreAnimation.
To sync the animations, explicitly set the animation duration and the timing function like below:
class ViewController: UIViewController {
...
override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
super.viewWillTransition(to: size, with: coordinator)
CATransaction.setAnimationDuration(coordinator.transitionDuration)
CATransaction.setAnimationTimingFunction(coordinator.completionCurve.timingFunction)
}
...
}
// Swift 4
extension UIView.AnimationCurve {
var timingFunction: CAMediaTimingFunction {
let functionName: CAMediaTimingFunctionName
switch self {
case .easeIn:
functionName = kCAMediaTimingFunctionEaseIn as CAMediaTimingFunctionName
case .easeInOut:
functionName = kCAMediaTimingFunctionEaseInEaseOut as CAMediaTimingFunctionName
case .easeOut:
functionName = kCAMediaTimingFunctionEaseOut as CAMediaTimingFunctionName
case .linear:
functionName = kCAMediaTimingFunctionLinear as CAMediaTimingFunctionName
}
return CAMediaTimingFunction(name: functionName as String)
}
}
In an NSTextView subclass I have created, I want to resize the height of the view to the height of the text within it. To execute this, I used apple's recommended procedure of counting lines within a text view:
private func countln() -> Int {
var nlines: Int
var index: Int
var range = NSRange()
let nGlyphs = lManager.numberOfGlyphs
for (nlines = 0, index = 0; index < nGlyphs; nlines++) {
lManager.lineFragmentRectForGlyphAtIndex(index, effectiveRange: &range)
index = NSMaxRange(range);
}
return nlines
}
This method works as expected and returns the correct number of lines in the text view. The issue lies in the resizing of the view, which I inserted into the delegate method that is called on text change:
func textDidChange(notification: NSNotification) {
let newHeight = CGFloat(28 * countln())
let ogHeight = self.frame.height
self.setFrameSize(NSSize(width: self.frame.width, height: newHeight))
self.setFrameOrigin(NSPoint(x: self.frame.origin.x, y: (self.frame.origin.y - self.frame.height) + ogHeight))
Swift.print(frame.height)
}
The setFrameSize variable function resizes the height of the view based not the number of lines in the view (multiplied by a constant that is more-or-less the height of each line of text). Everything works perfectly until immediately after the change of height is made, when the text view's height changes to an unanticipated incorrect height. I presume there is an issue with the frequent redrawing of the view in relation to the way I am resizing it. Any help on how to solve this issue of incorrect height resizing is greatly appreciated.
Thanks in advance.
I have a view hierarchy similar to the one in the image below (blue is the visible part of the scene):
So I have a UIScrollView with a lot of elements, out of which I am only showing the two button since they are relevant to the question. The first button is visible when the app is run, whereas the other one is positioned outside of the initially visible area. The first button is also the preferredFocusedView.
Now I am changing focus between the two buttons using a UIFocusGuide, and this works (checked it in didUpdateFocusInContext:). However, my scroll view does not scroll down when Button2 gets focused.
The scroll view is pinned to superview and I give it an appropriate content size in viewDidLoad of my view controller.
Any ideas how to get the scroll view to scroll?
Take a look at UIScrollView.panGestureRecognizer.allowedTouchTypes. It is an array of NSNumber with values based on UITouchType or UITouch.TouchType (depending on language version). By default allowedTouchTypes contains 2 values - direct and stylus. It means that your UIScrollView instance will not response to signals from remote control. Add the following line to fix it:
Swift 4
self.scrollView.panGestureRecognizer.allowedTouchTypes = [NSNumber(value: UITouchType.indirect.rawValue)]
Swift 4.2 & 5
self.scrollView.panGestureRecognizer.allowedTouchTypes = [NSNumber(value: UITouch.TouchType.indirect.rawValue)]
Also, don't forget to set a correct contentSize for UIScrollView:
self.scrollView.contentSize = CGSize(width: 1920.0, height: 2000.0)
Finally I solved this by setting scrollView.contentSize to the appropriate size in viewDidLoad.
You need to add pan gesture recognizer. I learned from here: http://www.theappguruz.com/blog/gesture-recognizer-using-swift. I added more code to make it not scrolling strangely, e.g. in horizontal direction.
var currentY : CGFloat = 0 //this saves current Y position
func initializeGestureRecognizer()
{
//For PanGesture Recoginzation
let panGesture: UIPanGestureRecognizer = UIPanGestureRecognizer(target: self, action: Selector("recognizePanGesture:"))
self.scrollView.addGestureRecognizer(panGesture)
}
func recognizePanGesture(sender: UIPanGestureRecognizer)
{
let translate = sender.translationInView(self.view)
var newY = sender.view!.center.y + translate.y
if(newY >= self.view.frame.height - 20) {
newY = sender.view!.center.y //make it not scrolling downwards at the very beginning
}
else if( newY <= 0){
newY = currentY //make it scrolling not too much upwards
}
sender.view!.center = CGPoint(x:sender.view!.center.x,
y:newY)
currentY = newY
sender.setTranslation(CGPointZero, inView: self.view)
}
I'm new but have managed to learn a lot and create a pretty awesome (I hope) app that's near completion. One of my last tasks is to create a PDF of dynamically generated user data. It has been the most frustrating part of this whole process as there is no real modern clear cut template or guide. Apple's documentation isn't very descriptive (and some parts I don't understand) and the Q/A here on stack and examples on Google all seem very case specific. I thought I almost had it by using a UIScrollView but the end result was messy and I couldn't get things to line up neat enough, nor did I have enough control.
I believe my flaws with this task are logic related and not knowing enough about available APIs, help on either is greatly appreciated.
I have dynamically created user content filling an NSArray in a subclass of a UIViewController. That content consists of Strings and Images.
I would like to use a UIView (I'm presuming in a .xib file) to create a template with header information for the first page of the PDF (the header information is dynamic as well), any page after that can be done via code as it really is just a list.
I have a small understanding of UIGraphicsPDF... and would like to draw the text and images into the PDF and not just take a screen shot of the view.
My trouble with getting this going is:
(I'm being basic here on purpose because what I have done so far has led me nowhere)
How do I find out how many pages I'm going to need?
How do I find out if text is longer than a page and how do I split it?
How do I draw images in the PDF?
How do I draw text in the PDF?
How do I draw both text and images in the PDF but padded vertically so there's no overlap and account for Strings with a dynamic number of lines?
How do I keep track of the pages?
Thank you for reading, I hoe the cringe factor wasn't too high.
So here we go. The following was made for OSX with NSView but it's easily adapatable for UIView (so I guess). You will need the following scaffold:
A) PSPrintView will handle a single page to print
class PSPrintView:NSView {
var pageNo:Int = 0 // the current page
var totalPages:Int = 0
struct PaperDimensions {
size:NSSize // needs to be initialized from NSPrintInfo.sharedPrintInfo
var leftMargin, topMargin, rightMargin, bottomMargin : CGFloat
}
let paperDimensions = PaperDimensions(...)
class func clone() -> PSPrintView {
// returns a clone of self where most page parameters are copied
// to speed up printing
}
override func drawRect(dirtyRect: NSRect) {
super.drawRect(dirtyRect)
// Drawing code here.
// e.g. to draw a frame inside the view
let scale = convertSize(NSMakeSize(1, 1), fromView:nil)
var myContext = NSGraphicsContext.currentContext()!.CGContext
CGContextSetLineWidth(myContext, scale.height)
CGContextSetFillColorWithColor(myContext, NSColor.whiteColor().CGColor)
CGContextFillRect (myContext, rect)
rect.origin.x += paperDimensions.leftMargin
rect.origin.y += paperDimensions.bottomMargin
rect.size.width -= paperDimensions.leftMargin + paperDimensions.rightMargin
rect.size.height -= paperDimensions.topMargin + paperDimensions.bottomMargin
CGContextSetStrokeColorWithColor(myContext, NSColor(red: 1, green: 0.5, blue: 0, alpha: 0.5).CGColor)
CGContextStrokeRect(myContext, rect)
// here goes your layout with lots of String.drawInRect....
}
}
B) PSPrint: will hold the single PSPrintViews in an array and when done send them to the (PDF) printer
class PSPrint: NSView {
var printViews = [PSPrintView]()
override func knowsPageRange(range:NSRangePointer) -> Bool {
range.memory.location = 1
range.memory.length = printViews.count
return true
}
func printTheViews() {
let sharedPrintInfo = NSPrintInfo.sharedPrintInfo()
let numOfViews = printViews.count
var totalHeight:CGFloat = 0;//if not initialized to 0 weird problems occur after '3' clicks to print
var heightOfView:CGFloat = 0
// PSPrintView *tempView;
for tempView in printViews {
heightOfView = tempView.frame.size.height
totalHeight = totalHeight + heightOfView
}
//Change the frame size to reflect the amount of pages.
var newsize = NSSize()
newsize.width = sharedPrintInfo.paperSize.width-sharedPrintInfo.leftMargin-sharedPrintInfo.rightMargin
newsize.height = totalHeight
setFrameSize(newsize)
var incrementor = -1 //default the incrementor for the loop below. This controls what page a 'view' will appear on.
//Add the views in reverse, because the Y position is bottom not top. So Page 3 will have y coordinate of 0. Doing this so order views is placed in array reflects what is printed.
for (var i = numOfViews-1; i >= 0; i--) {
incrementor++
let tempView = printViews[i] //starts with the last item added to the array, in this case rectangles, and then does circle and square.
heightOfView = tempView.frame.size.height
tempView.setFrameOrigin(NSMakePoint(0, heightOfView*CGFloat(incrementor))) //So for the rectangle it's placed at position '0', or the very last page.
addSubview(tempView)
}
NSPrintOperation(view: self, printInfo: sharedPrintInfo).runOperation()
}
C) a function to perform printing (from the menu)
func doPrinting (sender:AnyObject) {
//First get the shared print info object so we know page sizes. The shared print info object acts like a global variable.
let sharedPrintInfo = NSPrintInfo.sharedPrintInfo()
//initialize it's base values.
sharedPrintInfo.leftMargin = 0
sharedPrintInfo.rightMargin = 0
sharedPrintInfo.topMargin = 0
sharedPrintInfo.bottomMargin = 0
var frame = NSRect(x: 0, y: 0, width: sharedPrintInfo.paperSize.width-sharedPrintInfo.leftMargin-sharedPrintInfo.rightMargin, height: sharedPrintInfo.paperSize.height-sharedPrintInfo.topMargin-sharedPrintInfo.bottomMargin)
//Initiate the printObject without a frame, it's frame will be decided later.
let printObject = PSPrint ()
//Allocate a new instance of NSView into the variable printPageView
let basePrintPageView = PSPrintView(frame: frame)
// do additional init stuff for the single pages if needed
// ...
var printPageView:PSPrintView
for pageNo in 0..<basePrintPageView.totalPages {
printPageView = basePrintPageView.clone()
//Set the option for the printView for what it should draw.
printPageView.pageNo = pageNo
//Finally append the view to the PSPrint Object.
printObject.printViews.append(printPageView)
}
printObject.printTheViews() //print all the views, each view being a 'page'.
}
The PDF drawing code:
import UIKit
class CreatePDF {
// Create a PDF from an array of UIViews
// Return a URL of a temp dir / pdf file
func getScaledImageSize(imageView: UIImageView) -> CGSize {
var scaledWidth = CGFloat(0)
var scaledHeight = CGFloat(0)
let image = imageView.image!
if image.size.height >= image.size.width {
scaledHeight = imageView.frame.size.height
scaledWidth = (image.size.width / image.size.height) * scaledHeight
if scaledWidth > imageView.frame.size.width {
let diff : CGFloat = imageView.frame.size.width - scaledWidth
scaledHeight = scaledHeight + diff / scaledHeight * scaledHeight
scaledWidth = imageView.frame.size.width
}
} else {
scaledWidth = imageView.frame.size.width
scaledHeight = (image.size.height / image.size.width) * scaledWidth
if scaledHeight > imageView.frame.size.height {
let diff : CGFloat = imageView.frame.size.height - scaledHeight
scaledWidth = scaledWidth + diff / scaledWidth * scaledWidth
scaledHeight = imageView.frame.size.height
}
}
return CGSizeMake(scaledWidth, scaledHeight)
}
func drawImageFromUIImageView(imageView: UIImageView) {
let theImage = imageView.image!
// Get the image as it's scaled in the image view
let scaledImageSize = getScaledImageSize(imageView)
let imageFrame = CGRectMake(imageView.frame.origin.x, imageView.frame.origin.y, scaledImageSize.width, scaledImageSize.height)
theImage.drawInRect(imageFrame)
}
func drawTextFromLabel(aLabel: UILabel) {
if aLabel.text?.isEmpty == false {
let theFont = aLabel.font
let theAttributedFont = [NSFontAttributeName: theFont!]
let theText = aLabel.text!.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet()) as NSString
let theFrame = aLabel.frame
theText.drawInRect(theFrame, withAttributes: theAttributedFont)
}
}
func parseSubviews(aView: UIView) {
for aSubview in aView.subviews {
if aSubview.isKindOfClass(UILabel) {
// Draw label
drawTextFromLabel(aSubview as! UILabel)
}
if aSubview.isKindOfClass(UIImageView) {
// Draw image (scaled and at correct coordinates
drawImageFromUIImageView(aSubview as! UIImageView)
}
}
}
func parseViewsToRender(viewsToRender: NSArray) {
for aView in viewsToRender as! [UIView] {
UIGraphicsBeginPDFPageWithInfo(CGRectMake(0, 0, 612, 792), nil)
parseSubviews(aView)
}
}
func createPdf(viewsToRender: NSArray, filename: String) -> NSURL {
// Create filename
let tempDir = NSTemporaryDirectory()
let pdfFilename = tempDir.stringByAppendingPathComponent(filename)
UIGraphicsBeginPDFContextToFile(pdfFilename, CGRectZero, nil)
// begin to render the views in this context
parseViewsToRender(viewsToRender)
UIGraphicsEndPDFContext()
return NSURL(string: pdfFilename)!
}
}
First, I made a xib file with a UIView that fit the dimensions of a single PDF page and for my header information. This size is 612 points wide by 790 points tall.
Then I added UILabels for all of the page 1 header information I want to use (name, address, date, etc.)
I took note of y position and height of the lowest UILabel for my header information and subtracted it from the amount of vertical space in a page.
I also took note of the font and font size I wanted to use.
Then I created a class called CreatePDF
In that class I created several variables and constants, the font name, the font size, the size of a page, the remaining vertical space after header information.
In that class I created a method that takes two different arguments, one is a dictionary that I used for header information, the other is an array of UIImages and Strings.
That method calls a few other methods:
Determine the vertical height required for the items in the array
To do this I created another two methods, one to determine the height of a UILabel with any given string and one to determine the height of an image (vertical and horizontal images having different heights the way that I scale them). They each returned a CGFloat, which I added to a variable in the method that kept track of all the items in array.
For each item that was “sized” I then added another 8 points to use as a vertical offset.
Determine how many pages will be needed
The above method returned a CGFloat that I then used to figure out if either all the items will fit on one page below the header or if another page will be needed, and if so, how many more pages.
Draw a UIView
This method accepts the above mentioned dictionary, array and an estimated number of pages. It returns an array of UIViews.
In this method I create a UIView that matches the size of one PDF Page, I run a loop for each page and add items to it, I check to see if an item will fit by comparing it’s y position and height with the reaming vertical space on a page by subtracting the current Y position from the page height then I add an item and keep track of it’s height and y position, If the remaining height won’t work and I’m out of pages, I add another page.
Send the array to draw a PDF
I create the PDF context here
I take the array of UIViews as an argument, for each view I create a PDF Page in the PDF Context and then iterate through it’s subviews, if it’s a UILabel I send it off to a function that draws the UILabel at it’s frame position with it’s text property as the string. I create an attributed front using the variables defined in the class earlier. If it’s an image I send it to another function that also uses it’s frame, however I have to send it to yet another function to determine the actual dimensions of the image that’s drawn inside the UIImage (it changes based on scaling) and I return that for where to draw the image (this happens above too to properly size it).
That’s pretty much it, in my case I created the PDF context with a file, then end up returning the file to whoever calls this function. The hardest part for me to wrap my head around was keeping track of the vertical positioning.
I’ll work on making the code more generic and post it up somewhere.