I am trying to make the center portion of the view transparent like a camera overlay.
As shown in the below picture where the center portion is transparent while the remaining area is black colored with opacity.
I tried the below code.
Rectangle()
.fill(Color.red.opacity(0.5))
.mask(
Ellipse()
.fill(
Color.green.opacity(0.5)
)
.padding()
)
}
but the output is this.
Any help will be appreciated.
Thanks
This is adapted from #Asperi's answer here: https://stackoverflow.com/a/59659733/560942
struct MaskShape : Shape {
var inset : UIEdgeInsets
func path(in rect: CGRect) -> Path {
var shape = Rectangle().path(in: rect)
shape.addPath(Ellipse().path(in: rect.inset(by: inset)))
return shape
}
}
struct ContentView : View {
var body: some View {
ZStack {
Image("2")
.resizable()
.aspectRatio(contentMode: .fill)
GeometryReader { geometry in
Color.black.opacity(0.6)
.mask(
MaskShape(
inset: UIEdgeInsets(top: geometry.size.height / 6,
left: geometry.size.width / 6,
bottom: geometry.size.height / 6,
right: geometry.size.width / 6)
).fill(style: FillStyle(eoFill: true))
)
}
}
}
}
The ZStack sets up the image and then a semi-transparent black overlay on the top. The overlay is cut away with a mask with eoFill set to true. I added some code to provide insets for the mask, as I'm assuming this might be a variably-sized mask.
Lots of minutiae that can be changed (like the image aspect ratio, the insets, etc), but it should get you started.
Related
I'm using GeometryReader() and .frame() to show their comparability and playing with their width.
However the object wrapped in GeometryReader() doesn't have center alignment when width is less than minimum.
Please refer to attached gifs for demo.
Could you please help me with alignment?
Ideal:
Current:
struct ExampleView: View {
#State private var width: CGFloat = 50
var body: some View {
VStack {
SubView()
.frame(width: self.width, height: 120)
.border(Color.blue, width: 2)
Text("Offered Width is \(Int(width))")
Slider(value: $width, in: 0...200, step: 5)
}
}
}
struct SubView: View {
var body: some View {
GeometryReader { geometry in
Rectangle()
.fill(Color.yellow.opacity(0.6))
.frame(width: max(geometry.size.width, 120), height: max(geometry.size.height, 120))
}
}
}
That's because GeometryReader doesn't center its children.
You have to manually position the Rectangle by adding either a .position modifier or a .offset.
.position will move the origin of the rectangle's frame relative to the parent's center.
.offset will not change the frame, but rather change the rendering (working like a CGAffineTransform with translation).
The following modifiers to your Rectangle will yield the same results visually (though different under the hood):
Rectangle()
.fill(Color.yellow.opacity(0.6))
.frame(width: max(geometry.size.width, 120), height: max(geometry.size.height, 120))
.position(x: geometry.size.width / 2, y: geometry.size.height / 2)
or
let rectWidth = max(geometry.size.width, 120)
Rectangle()
.fill(Color.yellow.opacity(0.6))
.frame(width: rectWidth, height: max(geometry.size.height, 120))
.offset(x: ((geometry.size.width - rectWidth) / 2), y: 0)
Note that your rectangle's frame exceeds the bounds of its parent. I'd suggest to avoid that because it will cause all sorts of difficulties laying out other UI elements on the screen.
You could build it the other way around (unless your practical goal is to just understand how GeometryReader works):
struct ExampleView: View {
#State private var width: CGFloat = 50
var body: some View {
VStack {
let minWidth: CGFloat = 120
let subViewWidth: CGFloat = max(minWidth, width)
SubView(desiredWidth: width)
.frame(width: subViewWidth, height: 120)
.background(.yellow.opacity(0.6))
Text("Offered Width is \(Int(width))")
Slider(value: $width, in: 0...200, step: 5)
}
}
}
struct SubView: View {
let desiredWidth: CGFloat
var body: some View {
Rectangle()
.fill(.clear)
.border(Color.blue, width: 2)
.frame(width: desiredWidth, height: nil)
}
}
In this example the SubView has a yellow fill and a minimal frame width while the inner rectangle just takes whatever width is set on the slider. It also doesn't need a GeometryReader anymore. It looks and behaves the same but none of the views exceeds its parent's bounds anymore.
Problem
I am trying to create a view of a card with a symbol in the middle.
I tried to achieve this by creating a ZStack.
However, despite using .center alignment, the symbol always show in the top left.
Code
In the following code, the contentShape shows on the top-left despite alignment setting.
ZStack(alignment: .center) {
let baseShape = RoundedRectangle(cornerRadius: 10)
let contentShape = Rectangle()
.size(width: width, height: height)
.foregroundColor(getContentColor(color: card.color))
baseShape.fill().foregroundColor(.white)
baseShape.strokeBorder(lineWidth: 3, antialiased: true)
contentShape
}
Question
How do I properly align the contentShape at the center of the ZStack?
You need to use frame instead of size, because size is just for path drawing within provided rect, but rect here is entire area, so to fix use
ZStack(alignment: .center) {
let baseShape = RoundedRectangle(cornerRadius: 10)
let contentShape = Rectangle()
.frame(width: width, height: height) // << here !!
.foregroundColor(getContentColor(color: card.color))
baseShape.fill().foregroundColor(.white)
baseShape.strokeBorder(lineWidth: 3, antialiased: true)
contentShape
}
I have the following code:
struct CircleView: View {
var body: some View {
ZStack(alignment: .bottom) {
VStack{
Spacer()
Circle().frame(width: UIScreen.main.bounds.width/5)
}
}
}
}
Why is it not aligning the circle on the bottom? I have a spacer which should take up all free space in the ZStack?
Thanks in advance.
Because Circle is a Shape and does not have own content size, so consumes all provided. You limited width, but not height, so Circle consumed all height (blue rect is all circle, but drown only where fit).
So if you want to make it aligned, you have to limit it completely, like below
ZStack(alignment: .bottom) {
VStack{
Spacer()
Circle()
.frame(width: UIScreen.main.bounds.width/5, height: UIScreen.main.bounds.width/5)
}
}
It's a pretty straight-forward question - How does one apply a border effect to only the wanted edges of an Image with SwiftUI?
For example, I only want to apply a border to the top and bottom edges of an image because the image is taking up the entire width of the screen.
Image(mission.missionImageString)
.resizable()
.aspectRatio(contentMode: .fit)
.border(Color.white, width: 2) //Adds a border to all 4 edges
Any help is appreciated!
Demo
Implementation
You can use this modifier on any View:
.border(width: 5, edges: [.top, .leading], color: .yellow)
With the help of this simple extension:
extension View {
func border(width: CGFloat, edges: [Edge], color: Color) -> some View {
overlay(EdgeBorder(width: width, edges: edges).foregroundColor(color))
}
}
And here is the magic struct behind this:
struct EdgeBorder: Shape {
var width: CGFloat
var edges: [Edge]
func path(in rect: CGRect) -> Path {
var path = Path()
for edge in edges {
var x: CGFloat {
switch edge {
case .top, .bottom, .leading: return rect.minX
case .trailing: return rect.maxX - width
}
}
var y: CGFloat {
switch edge {
case .top, .leading, .trailing: return rect.minY
case .bottom: return rect.maxY - width
}
}
var w: CGFloat {
switch edge {
case .top, .bottom: return rect.width
case .leading, .trailing: return width
}
}
var h: CGFloat {
switch edge {
case .top, .bottom: return width
case .leading, .trailing: return rect.height
}
}
path.addRect(CGRect(x: x, y: y, width: w, height: h))
}
return path
}
}
If somebody ever needs to just add a quick 1 (or more) sided border to a view (e.g., the top edge, or any random combination of edges), I've found this works well and is tweakable:
top edge:
.overlay(Rectangle().frame(width: nil, height: 1, alignment: .top).foregroundColor(Color.gray), alignment: .top)
leading edge:
.overlay(Rectangle().frame(width: 1, height: nil, alignment: .leading).foregroundColor(Color.gray), alignment: .leading)
etc.
Just tweak the height, width, and edge to produce the combination of borders you want.
If you don't need to control thickness, you can do this:
.overlay(Divider(), alignment: .top)
.overlay(Divider(), alignment: .bottom)
Set the color of the divider using:
.overlay(Divider().background(.red), alignment: .left)
Add a top border aka Divider:
.overlay( Divider()
.frame(maxWidth: .infinity, maxHeight:1)
.background(Color.green), alignment: .top)
Example Usage:
Image("YouImageName")
.resizable()
.scaledToFit()
.frame(height: 40)
.padding(.top, 6) // padding above you Image, before your border
.overlay( Divider()
.frame(maxWidth: .infinity, maxHeight:1)
.background(Color.green), alignment: .top) // End Overlay
.padding(.top, 0) // padding above border
Explanation:
For a horizontal border aka Divider, frame width is the length of the border and height is the thickness of the border. Vertical border the frame width is thickness and frame height is the length.
The .background will set the color of the border.
Alignment will set, where the border will draw. For example "alignment: .bottom" will place the border on the bottom of the Image and "alignment: .top" on the top of the Image.
".leading & .trailing" will draw the border on the left and right of the Image correspondingly.
For a vertical border:
.overlay( Divider()
.frame(maxWidth: 1, maxHeight: .infinity)
.background(Color.green), alignment: .leading )
I find the most elegant solution is to create a custom shape and add it as an overlay. It works nicely with the SwiftUI image.
struct BottomBorder: Shape {
func path(in rect: CGRect) -> Path {
var path = Path()
path.move(to: CGPoint(x: rect.minX, y: rect.maxY))
path.addLine(to: CGPoint(x: rect.maxX, y: rect.maxY))
return path
}
}
struct ContentView: View {
var body: some View {
Image("image")
.overlay(BottomBorder().stroke(Color.red, lineWidth: 8))
}
}
a very easy way to accomplish this
VStack(spacing: 0) {
ViewThatNeedsABorder()
Divider() // or use rectangle
}
you could swap the divider for a rectangle as well and get the same effect. Style the divider or rectangle as needed using frame, or background etc.
if you need left/right borders use an HStack instead of a VStack, or even combine HStack and VStack to get borders on multiple sides ie: left and top.
I'd like to create a text view inside a circle view. The font size should be automatically set to fit the size of the circle. How can this be done in SwiftUI? I tried scaledToFill and scaledToFit modifiers, but they have no effect on the Text view:
struct ContentView : View {
var body: some View {
ZStack {
Circle().strokeBorder(Color.red, lineWidth: 30)
Text("Text").scaledToFill()
}
}
}
One possible "hack" is to use a big font size and a small scale factor so it will shrink itself:
ZStack {
Circle().strokeBorder(Color.red, lineWidth: 30)
Text("Text")
.padding(40)
.font(.system(size: 500))
.minimumScaleFactor(0.01)
}
}
You want to allow your text to:
shrink up to a certain limit
on 1 (or several) line(s)
You choose this scale factor limit to suit your need. Typically you don't shrink beyond readable or beyond the limit that will make your design look bad
struct ContentView : View {
var body: some View {
ZStack {
Circle().strokeBorder(Color.red, lineWidth: 30)
Text("Text")
.scaledToFill()
.minimumScaleFactor(0.5)
.lineLimit(1)
}
}
}
One can use GeometryReader in order to make it also work in landscape mode.
It first checks if the width or the height is smaller and then adjusts the font size according to the smaller of these.
GeometryReader{g in
ZStack {
Circle().strokeBorder(Color.red, lineWidth: 30)
Text("Text")
.font(.system(size: g.size.height > g.size.width ? g.size.width * 0.4: g.size.height * 0.4))
}
}
Here's a solution that hides the text resizing code in a custom modifier which can be applied to any View, not just a Circle, and takes a parameter specifying the fraction of the View that the text should occupy.
(I have to agree that while #szemian's solution is still not ideal, her method seems to be the best we can do with the current SwiftUI implementation because of issues inherent in the others. #simibac's answer requires fiddling to find a new magic number to replace 0.4 any time the text or its attributes--font, weight, etc.--are changed, and #giuseppe-sapienza's doesn't allow the size of the circle to be specified, only the font size of the text.)
struct FitToWidth: ViewModifier {
var fraction: CGFloat = 1.0
func body(content: Content) -> some View {
GeometryReader { g in
content
.font(.system(size: 1000))
.minimumScaleFactor(0.005)
.lineLimit(1)
.frame(width: g.size.width*self.fraction)
}
}
}
Using the modifier, the code becomes just this:
var body: some View {
Circle().strokeBorder(Color.red, lineWidth: 30)
.aspectRatio(contentMode: .fit)
.overlay(Text("Text")
.modifier(FitToWidth(fraction: fraction)))
}
Also, when a future version of Xcode offers SwiftUI improvements that obviate the .minimumScaleFactor hack, you can just update the modifier code to use it. :)
If you want to see how the fraction parameter works, here's code to let you adjust it interactively with a slider:
struct ContentView: View {
#State var fraction: CGFloat = 0.5
var body: some View {
VStack {
Spacer()
Circle().strokeBorder(Color.red, lineWidth: 30)
.aspectRatio(contentMode: .fit)
.overlay(Text("Text")
.modifier(FitToWidth(fraction: fraction)))
Slider(value: $fraction, in:0.1...0.9, step: 0.1).padding()
Text("Fraction: \(fraction, specifier: "%.1f")")
Spacer()
}
}
}
and here's what it looks like:
I had fixed size button and this worked for me to autoshrink long text.
Text("This is a long label that will be scaled to fit:")
.lineLimit(1)
.minimumScaleFactor(0.5)
Source: Apple
I did a mix of #Simibac's and #Anton's answers, only to be broken by iOS 14.0, so here's what I did to fix it. Should work on SwiftUI 1.0 as well.
struct FitSystemFont: ViewModifier {
var lineLimit: Int
var minimumScaleFactor: CGFloat
var percentage: CGFloat
func body(content: Content) -> some View {
GeometryReader { geometry in
content
.font(.system(size: min(geometry.size.width, geometry.size.height) * percentage))
.lineLimit(self.lineLimit)
.minimumScaleFactor(self.minimumScaleFactor)
.position(x: geometry.frame(in: .local).midX, y: geometry.frame(in: .local).midY)
}
}
}
As you can see I used the geometry proxy's frame(in:) method to get the local coordinate space, and then use .midX and .midY to center it properly, since proper centering is what broke for me on iOS 14.
Then I set up an extension on View:
extension View {
func fitSystemFont(lineLimit: Int = 1, minimumScaleFactor: CGFloat = 0.01, percentage: CGFloat = 1) -> ModifiedContent<Self, FitSystemFont> {
return modifier(FitSystemFont(lineLimit: lineLimit, minimumScaleFactor: minimumScaleFactor, percentage: percentage))
}
}
So usage is like this:
Text("Your text")
.fitSystemFont()
To achieve this you don't need the ZStack. You can add a background to the Text:
Text("Text text text?")
.padding()
.background(
Circle()
.strokeBorder(Color.red, lineWidth: 10)
.scaledToFill()
.foregroundColor(Color.white)
)
The result is this:
Building on #JaimeeAz answer. Added an option to specify the minimum font.
import SwiftUI
public struct FitSystemFont: ViewModifier {
public var lineLimit: Int?
public var fontSize: CGFloat?
public var minimumScaleFactor: CGFloat
public var percentage: CGFloat
public func body(content: Content) -> some View {
GeometryReader { geometry in
content
.font(.system(size: min(min(geometry.size.width, geometry.size.height) * percentage, fontSize ?? CGFloat.greatestFiniteMagnitude)))
.lineLimit(self.lineLimit)
.minimumScaleFactor(self.minimumScaleFactor)
.position(x: geometry.frame(in: .local).midX, y: geometry.frame(in: .local).midY)
}
}
}
public extension View {
func fitSystemFont(lineLimit: Int? = nil, fontSize: CGFloat? = nil, minimumScaleFactor: CGFloat = 0.01, percentage: CGFloat = 1) -> ModifiedContent<Self, FitSystemFont> {
return modifier(FitSystemFont(lineLimit: lineLimit, fontSize: fontSize, minimumScaleFactor: minimumScaleFactor, percentage: percentage))
}
}
I had the same problem for a Timer. Unfortunately a timer changes the text once a second, so the text was jumping around and scaling up and down all the time.
My approach was to figure, what was the longest possible timer that could be displayed - in my case "-44:44:44" - and with 50pt size that would result in a 227.7pt big frame. 227 divided by 50 (point size I used before) a width of 4.5 (rounded down) per point size.
Careful: with 1pt size it gave me a 5.3 point big frame - so the bigger the font the closer to the actual text size without the frame it gets.
As I was using a GeometryReader anyway I could simple set a fixed text size, using
Text("-44:44:44")
.font(.system(size: geometry.size.width / 4.5))
Works perfectly well, if there is no '-' or no hours shown I have some space to the left and right, but the text doesn't jump around.
this could be refined with different scale-factors, depending on the amount of digits shown there - so another scale factor for "-mm:ss".
This would lead to a "jump" when the hours are shown or hidden - but that happens rarely for my need.