In my Swift 2 iOS 9.0 project I've set up a UIScrollView with a UIImageView and some buttons and labels. For some other reasons the scrollView's frame is 652 points wide and 652 points high. Its content is decided by the image in the imageView (it's 1000x1000):
func loadImageOntoView(FloorImage:UIImage) -> Void {
mapImageView.image = FloorImage
// containerView is my root view, same size as the screen
let cw = containerView.frame.width
let ch = containerView.frame.height
let cd = sqrt(cw*cw + ch*ch)
/* Here I set scrollView's frame to be a square with sides as
long as containerView's diagonal. This makes sure that if the scrollView
is rotated it's always bigger than the screen*/
scrollView.frame = CGRect(
x: -(cd-cw)/2, y: -(cd-ch)/2,
width: cd, height: cd
)
scrollView.contentSize = FloorImage.size
//Here it centers the imageView in the scrollView
mapImageView.center = CGPoint(
x: scrollView.frame.size.width/2, y: scrollView.frame.size.height/2)
scrollView.minimumZoomScale = 0.9
scrollView.maximumZoomScale = 15.1
}
I'm not completely sure on these scrollViews, but I thought it was supposed to be able to scroll with these settings? When I zoom in I can scroll, but when the zoomScale = 1 it doesn't work. What have I done wrong, or how should I go about using scrollViews?
Related
I have a color palette imageview, in that I want to place a plus icon(imageView) according to the x and y-axis I am getting from the backend. If I get x = 0 and y = 0 the frame of the plus is placing correctly
For y axis if I set height of the color palette imageView to the plus icon's frame's y axis, the icon is not going to the actual (0,0)
.
The code I used is below
let cWidth = self.colorPalleteImageView.frame.size.width // 348
let cHeight = self.colorPalleteImageView.frame.size.height // 378.5
let imageView = UIImageView(image: appImages.roundPlusIcon.image)
imageView.frame = CGRect(x: 0, y: cHeight, width: 22, height: 22)
colorPalleteImageView.addSubview(imageView)
I am checking this with iPad 12.9 inch simulator. Am I missing anything to achieve that x=0 and y=0, If I give the width of the colorPaletteImage to the x-axis of plusIconImageView it is not going to end fo the x-axis, It stays before the end of the width of the imageview, I don't know why it is happening, Need help
You're using frame sizes before the frames are finished being set by auto-layout.
I'd suggest using constraints, but if you want to stick to frame coordinates...
add the "round plus" icon imageView in viewDidLoad()
set its frame.origin in viewDidLayoutSubviews() or viewDidAppear()
imageView.frame = CGRect(x: cWidth, y: cHeight, width: 22, height: 22)
mast be:
imageView.frame = CGRect(x: 0, y: 0, width: 22, height: 22)
as axes are:
0,0-----------------> x
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V
with 0,0 you put top left of little image to to top left of big.
You can fix this issue by modifying the height property to the super view's bound's height. You need to know the difference between frame and bounds to understand why this is happening. In simple words frame is the CGRect with respect to it's super view and bounds is the CGRect with respect to it's own coordinates.
Plenty of detailed explanations are available online just need to google frame vs bounds and you'll get used to both of these after you play with it many times.
Here's how you fix this issue.
let cHeight = self.colorPalleteImageView.bounds.size.height
sorry.. I am back
I did (to follow your code I forced values..)
import UIKit
class ViewController: UIViewController {
#IBOutlet weak var colorPalleteImageView: UIImageView!
override func viewDidLoad() {
super.viewDidLoad()
let v = self.view
print(v!.frame)
let cHeight = CGFloat(378.5)
colorPalleteImageView.frame.size.width = 348
colorPalleteImageView.frame.size.height = cHeight
let plusImg = UIImage(named: "plus")
let imageView = UIImageView(image: plusImg)
imageView.frame = CGRect(x: 0, y: cHeight-22, width: 22, height: 22)
colorPalleteImageView.addSubview(imageView)
}
}
and I got: (on iPad)
I'm trying to understand how iOS frame and bounds works.
I put an subView:UIView on UIViewController and a button which can increase subView's frame origin coordinate and change textlabel with its value.
like this,
let subView: UIView = UIView(frame: CGRect(x: 50, y: 50, width: 100, height: 100))
override func viewDidLoad() {
super.viewDidLoad()
view.addSubview(subView)
subView.backgroundColor = .blue
}
#IBAction func btnMoveBottomView(_ sender: Any) {
subView.frame.origin.y = subView.frame.origin.y + 100
lbFrameInfo.text = String(format:"sub = (%.1f, %.1f)", subView.frame.origin.x, subView.frame.origin.y)
self.view.setNeedsLayout()
self.view.layoutIfNeeded()
}
After I make this action, I see subView go down but text doesn't change.
on debug console I see this change
po subView.frame.origin
▿ (50.0, 2350.0)
- x : 50.0
- y : 2350.0
updateViewConstraints has been called too.
override func updateViewConstraints() {
print("updateViewConstraints")
super.updateViewConstraints()
}
Instead of increasing frame.origin.x like this, increasing value of leading constant works perfectly.
It would be appreciated if someone can guide me the differences of these and the concept of frame and if it is related with auto-layout things
According to your question,
You have added subView to ViewController view so when u create view
let subView: UIView = UIView(frame: CGRect(x: 50, y: 50, width: 100, height: 100))
and do this
view.addSubview(subView)
it means your subview will be at 50 position down and away from left of the screen.
so when u do this.
subView.frame.origin.y = subView.frame.origin.y + 100
it will move your frame further down in the screen as you are changing the y position of frame which is the starting position of creating your view on screen.
At its simplest, a view’s bounds refers to its coordinates relative to its own view (as if the rest of your view hierarchy didn’t exist), whereas its frame refers to its coordinates relative to its parent’s view. Frame will reflect the position in its parents view.
This means a few things:
1.If you create a view at X:0, Y:0, width:100, height:100, its frame and bounds are the same.
2.If you move that view to X:100, its frame will reflect that change but its bounds will not. Remember, the bounds is relative to the view’s own space, and internally to the view nothing has changed.
3.If you transform the view, e.g. rotating it or scaling it up, the frame will change to reflect that, but the bounds still won’t – as far as the view is concerned internally, it hasn’t changed
hope it clears your doubts
I have a imageView inside a UIView which displays on top of button when that button is tapped. The position of the button is dynamic.
If the button is on the extreme right of the screen, on tap of that button, half of the view which displays is going out of screen (i.e., only half is displayed)
In the code below, I'm setting my view's frame equal to image width and its height, imageView's position is (center of image is on top center of button )
Pls advice how i can reposition the such that the view will always inside the bounds. Below is the code Im using to display my custom view on top of button
//calculate frame for view
let imageHeight = myImage.size.height
let imageWidth = myImage.size.width
let imageX = myButton.minX -
((myView.myImageView.bounds.width)/2) + 15
let imageY = currentCellRect.minY -
(myView.myImageView.bounds.height) + 15
let imageFrame = CGRect(x: imageX, y: imageY, width:
imageWidth, height: imageHeight)
//Assign calculated from to the tool tip view
toolTipView.frame = imageFrame
After calculating imageWidth and imageX you could make a check like this:
[...]
var imageX = myButton.minX -
((myView.myImageView.bounds.width)/2) + 15
imageX = min(imageX, view.frame.width - imageWidth)
[...]
Notice that i changed imageX from let to var.
I have an image which is set inside a scroll view, though I have set the frame of the scrollView to fixed height and width as shown below, the image goes beyond the bounds (see below picture).
How can I limit the picture to fit inside the scrollView.
imageScrollView.frame = CGRect(x: 0, y: 0, width: viewWidth, height: viewHeight-50)
imageScrollView.clipsToBounds = true // Has no affect on the image
Do you have a reference to the UIImageView? If so, then set its content mode to aspect fit. Like this:
theImageView.contentMode = .scaleAspectFit
The clipsToBounds you set only covers up any parts of child views that are sticking out of the bounds of the parent view, so that's why it doesn't do anything for you.
OR if you're using Interface Builder, set this option:
So, what if you don't have the reference to the UIImageView?...
You could iterate through the subviews of your scroll view, and whenever it finds a UIImageView, you can set the content mode like that. Something like:
//This is off the top of my head, so my filtering may not be right...
//This is also a one and done solution if you've got a lot of images in your scroll view
for anImgVw in imageScrollView.subviews.filter({$0.isKind(of: UIImageView.self)})
{
anImgVw.contentMode = .scaleAspectFit
}
Otherwise, I'm not sure if it's possible without a reference to the UIImageView.
The library you are using is coded to match the scaling to the device orientation. So, if the image orientation doesn't match the view orientation, you end up with the image not quite fitting in your scroll view.
You'll need to edit the ImageScrollView.swift source file. Assuming you're using the same version that is currently at the link you provided ( https://github.com/huynguyencong/ImageScrollView ), change the setMaxMinZoomScalesForCurrentBounds() function as follows:
fileprivate func setMaxMinZoomScalesForCurrentBounds() {
// calculate min/max zoomscale
let xScale = bounds.width / imageSize.width // the scale needed to perfectly fit the image width-wise
let yScale = bounds.height / imageSize.height // the scale needed to perfectly fit the image height-wise
// fill width if the image and phone are both portrait or both landscape; otherwise take smaller scale
//let imagePortrait = imageSize.height > imageSize.width
//let phonePortrait = bounds.height >= bounds.width
//var minScale = (imagePortrait == phonePortrait) ? xScale : min(xScale, yScale)
//
// just take the min scale, so the image will completely fit regardless of orientation
var minScale = min(xScale, yScale)
let maxScale = maxScaleFromMinScale*minScale
// don't let minScale exceed maxScale. (If the image is smaller than the screen, we don't want to force it to be zoomed.)
if minScale > maxScale {
minScale = maxScale
}
maximumZoomScale = maxScale
minimumZoomScale = minScale * 0.999 // the multiply factor to prevent user cannot scroll page while they use this control in UIPageViewController
}
you can use the screenHeight rather than the viewHeight
let screenSize: CGRect = UIScreen.mainScreen().bounds
let screenWidth = screenSize.width
let screenHeight = screenSize.height
imageScrollView.frame = CGRect(x: 0, y: 0, width: viewWidth, height: screenHeight-50)
I need to create three dynamic columns, each with a fixed percentage of the total width. Not thirds, but different values. For example, the following illustration shows three columns: the first being 42% wide, the second being 25% wide, and the third being 33% wide.
For a 600 pixel across viewcontroller, that would be 252, 150, and 198 pixels respectively.
However, for any subsequent display sizes (i.e. iPhone 4 landscape (960 wide) or iPad 2 portrait (768 wide), I would like the relative percentages to be the same (not the pixel widths quoted above).
Is there a way to do this using Storyboards (i.e. without code)? I can do this easily in code, but my goal is to put as much of this display logic as possible into the Storyboard.
If, as you say, you know how to do it in code, then you already know how to do it in the storyboard. It's exactly the same constraints, but you are creating them visually rather than in code.
Select both a view and its superview.
Choose Editor -> Pin -> Widths Equally to constrain the width to be equal to the superview's width (actually the "pin" popup dialog at the bottom of the canvas works best here).
Edit the constraint and set the Multiplier to the desired fraction, e.g. 0.42. And so too for the other views.
As Apple introduces UIStackView it made job much easy.
Method 1: Using Nib/StoryBoard:
You have to just add three view in interface builder & embed them into stackview
Xcode ► Editor ► Embed in ► StackView
Select stackView & give constraint with leading, trailing, top & equal height with safeArea
Click to Attribute inspector area &
Set StackView horizontal & distribution to fill proportionally
[3
Give constraint of three view with leading, trailing, top, bottom with respective of sides.
Method 2: Programmatically:
import UIKit
class StackViewProgramatically: UIViewController {
var propotionalStackView: UIStackView!
///Initially defining three views
let redView: UIView = {
let view = UIView()//taking 42 % initially
view.frame = CGRect(x: 0, y: 0, width: 42 * UIScreen.main.bounds.width/100, height: UIScreen.main.bounds.height)
view.backgroundColor = .red
return view
}()
let greenView: UIView = {
let view = UIView()//taking 42* initially
view.frame = CGRect(x: 42 * UIScreen.main.bounds.width/100, y: 0, width: 25 * UIScreen.main.bounds.width/100, height: UIScreen.main.bounds.height)
view.backgroundColor = .green
return view
}()
let blueView: UIView = {
let view = UIView()//taking 33*initially
view.frame = CGRect(x: 67 * UIScreen.main.bounds.width/100, y: 0, width: 33 * UIScreen.main.bounds.width/100, height: UIScreen.main.bounds.height)
view.backgroundColor = .blue
return view
}()
///Changing UIView frame to supports landscape mode.
override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
super.viewWillTransition(to: size, with: coordinator)
DispatchQueue.main.async {
self.redView.frame = CGRect(x: 0, y: 0, width: 42 * self.widthPercent, height: self.screenHeight)
self.greenView.frame = CGRect(x: 42 * self.widthPercent, y: 0, width: 25 * self.widthPercent, height: self.screenHeight)
self.blueView.frame = CGRect(x: 67 * self.widthPercent, y: 0, width: 33 * self.widthPercent, height: self.screenHeight)
}
}
override func viewDidLoad() {
super.viewDidLoad()
//Adding subViews to the stackView
propotionalStackView = UIStackView()
propotionalStackView.addSubview(redView)
propotionalStackView.addSubview(greenView)
propotionalStackView.addSubview(blueView)
propotionalStackView.spacing = 0
///setting up stackView
propotionalStackView.axis = .horizontal
propotionalStackView.distribution = .fillProportionally
propotionalStackView.alignment = .fill
view.addSubview(propotionalStackView)
}
}
//MARK: UIscreen helper extension
extension NSObject {
var widthPercent: CGFloat {
return UIScreen.main.bounds.width/100
}
var screenHeight: CGFloat {
return UIScreen.main.bounds.height
}
}
Output:
Works with landscape & portrait
Demo project - https://github.com/janeshsutharios/UIStackView-with-constraints
https://developer.apple.com/videos/play/wwdc2015/218/
I think this can be explained in more detail so it can be more easily applied to any number of views requiring fixed percentage layouts within a superview.
Left-most view
Anchored to SuperView.Leading
Defines its fixed percentage as a multiplier on the SuperView.Height
Intermediate views
Defines its fixed percentage as a multiplier on the SuperView.Height
Pins its left to its neighbor's right
Right-Most view
Does not define a fixed percentage (it is the remainder of the available view)
Pins its left to its neighbor's right
Pins its right to SuperView.Trailing
All Views
Define their non-fixed heights by anchoring to Top Layout Guide.Top and Top Layout Guide.bottom. In the answer above, it is noted that this can also be done by setting equal height to the neighboring view.