i want to fetch the current orientation of device. I have written this code in AppDelegate class :
my code:
if (UIInterfaceOrientation.LandscapeLeft == (UIInterfaceOrientation)UIDevice.CurrentDevice.Orientation &&
UIInterfaceOrientation.LandscapeRight == (UIInterfaceOrientation)UIDevice.CurrentDevice.Orientation) {
//code
} else {
//code
}
UIDevice.CurrentDevice.Orientation is giving unknown?
Can you use the InterfaceOrientation property of your UIViewController?
That is probably a better value to check against, as it is the state in which your app is currently rotated and "allowed" to rotate to. Checking the UIDevice might not match the rotation of your UI.
Related
So the problem I am facing is that when the viewModel data updates it doesn't seems to update the state of my bytearrays: ByteArray by (mutableStateOf) and mutableListOf()
When I change pages/come back to the page it does update them again. How can get the view to update for things like lists and bytearrays
Is mutableStateOf the wrong way to update bytearrays and lists? I couldn't really find anything useful.
Example of byte array that doesn't work (using this code with a Float by mutableStateOf works!).
How I retrieve the data in the #Composable:
val Data = BluetoothMonitoring.shared.Data /*from a viewModel class, doesn't update when Data / bytearray /list changes, only when switching pages in app.*/
Class:
class BluetoothMonitoring : ViewModel(){
companion object {
val shared = BluetoothMonitoring()
}
var Data : ByteArray by mutableStateOf( ByteArray(11) { 0x00 })
}
Any help is appreciated and thanks in advance!
You seem to come from IOS/Swift where using Shared objects is a common pattern
In Android, you're not supposed to create a viewmodel instance by hand, you are supposed to use ViewModelFactory, or compose viewModel() function. The ViewModel object basically preserves some data for you across activity recompositions, i.e. when activity is paused, resumed etc
The general good way of structuring your app is using UDF (Unidirectional Data Flow) where, data flows upwards towards the view/composable and events flow downwards towards the viewmodel, data layer etc. We use something called as Flow which is a reactive data stream, which updates the listener whenever some value changes
Keeping in mind these two points, I've created a very brief way of how you could restructure your code, so that it almost always works. Please adapt accordingly to your logic
class MyViewModel: ViewModel(){
// Declare a flow in the viewModel
var myData = MutableStateFlow(0)
fun modifyMyData(newData: Int){
myData = newData
}
}
And in your composable view layer
#Composable
fun YourComposable(){
val myViewModel = viewModel()
val myUiState by myViewModel.myData.collectAsState()
// Now use your value, and change it, it will be changed accordingly and updated everywhere
}
I also recommend reading this codelab
How I handle byte arrays over Bluetooth with kotlin and Android.
I'm talking sic (communication) to arduino over bluetooth in the app I'm making. Kotlin likes Byte and Arduino likes UBYTE so I do all of those translations in the app because Kotlin threads are inline code easy and the phone has more power for such things.
Add toByte() to everthing that is outbound. <- (actual solution)
outS[8] = Color.alpha(word.color).toByte()
outS[9] = Color.red(word.color).toByte()
outS[10] = Color.green(word.color).toByte()
outS[11] = Color.blue(word.color).toByte()
outS[12] = 0.toByte()
outS[13] = 232.toByte()
outS[14] = 34.toByte()
outS[15] = 182.toByte()
//outS[16] = newline working without a newLine!
// outS[16] = newline
val os = getMyOutputStream()
if (os != null) {
os.write(outS)
}
For inbound data...I have to change everything to UByte. <- (actual solution)
val w: Word = wordViewModel.getWord(i)
if (w._id != 0) {
w.rechecked = (byteArray[7].toInt() != 0)
w.recolor = Color.argb(
byteArray[8].toUByte().toInt(),
byteArray[9].toUByte().toInt(),
byteArray[10].toUByte().toInt(),
byteArray[11].toUByte().toInt()
)
//finally update the word
wordViewModel.update(w)
}
My Youtube channel is about model trains not coding there some android and electronics in there. And a video of bluetooth arduino android is coming soon like tonight or tomorrow soon. I've been working on the app for just over a month using it to learn Kotlin. The project is actually working but I have to do the bluetooth connection manually the app actually controls individual neopixels for my model train layout.
I am making a practice simple app as I am learning swiftUI. My current problem seems to lie in this function:
variables
#State var cameras: [Camera] = []
#State var angle: Double = 0.0
func fetchAngle(){
COLLECTION_CAMERAS.whereField("active", isEqualTo: true).addSnapshotListener { snapshot, _ in
self.cameras = snapshot!.documents.compactMap({ try? $0.data(as: Camera.self)})
self.angle = cameras[0].angle
}
There can only be one active camera out of the three.
I know its bad practice but all the program is in the MainView() for simplicity, after I finish debugging I will use MVVM.
The angle variable is #Published, because I want to redraw the user interface when its updated.
The there is a set of 3 buttons and each time I press one of them, successfully update in firebase the active field to true or false.
As there are three cameras I fetch the collection and wish to only get the camera where the active field is true. So far so good, my problem starts (I think) with this code self.angle = cameras[0].angle. What I wish to achieve is to be able to set self.angle with the angle of the only camera that has active == true.
I'm new to Swift and followed a simple tutorial to make a magic 8 ball Cocoa App that every time I click the ball it shows a different piece of advice. I am now trying to practice my UI automated tests by asserting (XCTAssert) that the "Piece of Advice" label is equal to one of the string values in my array.
My array looks like this and is in my ViewController.swift:
var adviceList = [
"Yes",
"No",
"Tom says 'do it!'",
"Maybe",
"Try again later",
"How can I know?",
"Totally",
"Never",
]
How can I make an assertion in my UITests.swift file that asserts that the string that is shown is equal to one of the string values in the array above?
It's possible that you're asking how to access application state from a UI test, or just in general UI testing.
I think it's a pretty interesting question so I'm going to answer because it's something that I don't know a lot about and hopefully will prompt other people to chime in and correct.
Background: A basic Magic 8 Ball project
I set up a basic project with a view controller that contains two views: a label and a button. Tapping the button updates the label text with a random message:
import UIKit
struct EightBall {
static let messages = ["Yes", "No", "It's not certain"]
var newMessage: String {
let randomIndex = Int(arc4random_uniform(UInt32(EightBall.messages.count)))
return EightBall.messages[randomIndex]
}
}
class ViewController: UIViewController {
let ball = EightBall()
#IBOutlet weak var messageLabel: UILabel!
#IBAction func shakeBall(_ sender: Any) {
messageLabel.text = ball.newMessage
}
}
A basic UI test
Here's a commented UI test showing how to automate tapping on the button, and grabbing the value of the label, and then checking that the value of the label is a valid message.
import XCTest
class MagicUITests: XCTestCase {
// This method is called before the invocation of each test method in the class.
override func setUp() {
super.setUp()
// In UI tests it is usually best to stop immediately when a failure occurs.
continueAfterFailure = true
// UI tests must launch the application that they test. Doing this in setup will make sure it happens for each test method.
XCUIApplication().launch()
}
func testValidMessage() {
// Grab reference to the application
let app = XCUIApplication()
// #1
// Grab reference to the label with the accesability identifier 'MessageLabel'
let messagelabelStaticText = app.staticTexts["MessageLabel"]
// Tap the button with the text 'Shake'
app.buttons["Shake"].tap()
// get the text of the label
let messageLabelText = messagelabelStaticText.label
// #2
// check if the text in the label matches one of the allowed messages
let isValidMessage = EightBall.messages.contains(messageLabelText)
// test will fail if the message is not valid
XCTAssert(isValidMessage)
}
}
At #1 The approach that I'm using to get the label is to access the labels accessibilityIdentifier property. For this project I entered this through storyboard, but if you're setting your views up in code you can directly set the accessibilityIdentifier property yourself.
The other thing that's confusing here is that to get access to elements in the view you're not navigating the view hierarchy, but a proxy of the hierarchy, which is why the syntax to get a label is the odd 'staticTexts' (The references at the bottom of the post explain this in more detail).
For #2 I'm inspecting the structure defined in my project. In a unit test you could access this my importing #testable import ProjectName but unfortunately this approach doesn't work for UI Test.
Instead, you'll have to make sure that any source file you want to access from the UI test is included as a target. You can do this in Xcode from this panel by checking the name of your UI test:
More UI testing references:
UI Testing Intro: http://www.mokacoding.com/blog/xcode-7-ui-testing/
UI Testing Cheat Sheet: http://masilotti.com/ui-testing-cheat-sheet/
You can set the autocapitalizationType property of a UITextField so all input is in upper case. I find that does work fine on the simulator (when actually tapping the simulator's keypad, not the Mac's keyboard), but not on the device? Everything stays lowercase.
In the UICatalog demo I added to the textFieldNormal method:
textFieldNormal.autocapitalizationType = UITextAutocapitalizationTypeAllCharacters;
Added a delegate too, to display the actual autocapitalizationType for the UITextField:
- (void)textFieldDidBeginEditing:(UITextField *)textField
{
NSLog( #"textField.autocapitalizationType=%d", textField.autocapitalizationType );
}
It will properly display 3 (=UITextAutocapitalizationTypeAllCharacters), but anything you tap remains lowercase. What am I missing?
Apparently this is a device general settings issue: Settings -> General -> Keyboard -> Auto-Capitalization must be ON to honour the setting of textField.autocapitalizationType to all upper case, else setting the property is ignored, apparently. If I switch it on everything works as expected.
You could try something like this the the textfield delegate:
-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
if (range.length == 0) { // not deleting , but adding a char
textField.text = [textField.text stringByAppendingString:[string uppercaseString]];
return NO;
}
return YES;
}
This works only if you try to insert a symbol at the end of the text.
Should you want to play with the text in the middle you could play with
range.location
and also you will need to play with the cursor positioning as it will go at the end every time...
I hope this helps someone.
Has anyone seen a decent answer to this problem?
initialLayoutAttributesForAppearingItemAtIndexPath seems to be being called for all visible cells, not just the cell being inserted. According to Apple's own docs:
For moved items, the collection view uses the standard methods to retrieve the item’s updated layout attributes. For items being inserted or deleted, the collection view calls some different methods, which you should override to provide the appropriate layout information
Which doesn't sound like what is happening... the other cells aren't being inserted, they are being moved, but it's calling initialLayoutAttributesForAppearingItemAtIndexPath for the ones being moved too.
I have seen work arounds using prepareForCollectionViewUpdates: to trace which indexPaths are being updated and only changing those, but this seems a bit odd that it's going agains their own docs. Has anyone else found a better way around this?
I found this blog post by Mark Pospesel to be helpful.
The author also fixed WWDC CircleLayout sample and posted it on Github.
Methods of interest:
- (void)prepareForCollectionViewUpdates:(NSArray *)updateItems
{
// Keep track of insert and delete index paths
[super prepareForCollectionViewUpdates:updateItems];
self.deleteIndexPaths = [NSMutableArray array];
self.insertIndexPaths = [NSMutableArray array];
for (UICollectionViewUpdateItem *update in updateItems)
{
if (update.updateAction == UICollectionUpdateActionDelete)
{
[self.deleteIndexPaths addObject:update.indexPathBeforeUpdate];
}
else if (update.updateAction == UICollectionUpdateActionInsert)
{
[self.insertIndexPaths addObject:update.indexPathAfterUpdate];
}
}
}
- (void)finalizeCollectionViewUpdates
{
[super finalizeCollectionViewUpdates];
// release the insert and delete index paths
self.deleteIndexPaths = nil;
self.insertIndexPaths = nil;
}
// Note: name of method changed
// Also this gets called for all visible cells (not just the inserted ones) and
// even gets called when deleting cells!
- (UICollectionViewLayoutAttributes *)initialLayoutAttributesForAppearingItemAtIndexPath:(NSIndexPath *)itemIndexPath
{
// Must call super
UICollectionViewLayoutAttributes *attributes = [super initialLayoutAttributesForAppearingItemAtIndexPath:itemIndexPath];
if ([self.insertIndexPaths containsObject:itemIndexPath])
{
// only change attributes on inserted cells
if (!attributes)
attributes = [self layoutAttributesForItemAtIndexPath:itemIndexPath];
// Configure attributes ...
attributes.alpha = 0.0;
attributes.center = CGPointMake(_center.x, _center.y);
}
return attributes;
}
// Note: name of method changed
// Also this gets called for all visible cells (not just the deleted ones) and
// even gets called when inserting cells!
- (UICollectionViewLayoutAttributes *)finalLayoutAttributesForDisappearingItemAtIndexPath:(NSIndexPath *)itemIndexPath
{
// So far, calling super hasn't been strictly necessary here, but leaving it in
// for good measure
UICollectionViewLayoutAttributes *attributes = [super finalLayoutAttributesForDisappearingItemAtIndexPath:itemIndexPath];
if ([self.deleteIndexPaths containsObject:itemIndexPath])
{
// only change attributes on deleted cells
if (!attributes)
attributes = [self layoutAttributesForItemAtIndexPath:itemIndexPath];
// Configure attributes ...
attributes.alpha = 0.0;
attributes.center = CGPointMake(_center.x, _center.y);
attributes.transform3D = CATransform3DMakeScale(0.1, 0.1, 1.0);
}
return attributes;
}
You're not alone. The UICollectionViewLayout header file comments make things a little clearer.
For each element on screen before the invalidation,
finalLayoutAttributesForDisappearingXXX will be called and an
animation setup from what is on screen to those final attributes.
For each element on screen after the invalidation,
initialLayoutAttributesForAppearingXXX will be called an an animation
setup from those initial attributes to what ends up on screen.
Basically finalLayoutAttributesForDisappearingItemAtIndexPath is called for each item on screen before the animation block starts, and initialLayoutAttributesForAppearingItemAtIndexPath is called for each item after the animation block ends. It's up to you to cache the array of UICollectionViewUpdateItem objects sent in prepareForCollectionViewUpdates so you know how to setup the initial and final attributes. In my case I cached the previous layout rectangles in prepareLayout so I knew the correct initial positions to use.
One thing that stumped me for a while is you should use super's implementation of initialLayoutAttributesForAppearingItemAtIndexPath and modify the attributes it returns. I was just calling layoutAttributesForItemAtIndexPath in my implementation, and animations weren't working because the layout positions were different.
If you've subclassed UICollectionViewFlowLayout, you can call the super implementation. Once you've got the default initial layout, you can check for an .alpha of 0. If alpha is anything other than 0, the cell is being moved, if it's 0 it's being inserted.
Bit of a hack, I know, but it works 👍.
Swift 2.0 implementation follows:
override func initialLayoutAttributesForAppearingItemAtIndexPath(itemIndexPath: NSIndexPath) -> UICollectionViewLayoutAttributes? {
guard let attributes = super.initialLayoutAttributesForAppearingItemAtIndexPath(itemIndexPath) where attributes.alpha == 0 else {
return nil
}
// modify attributes for insertion here
return attributes
}
Make sure you're using new method signature in Swift 3. Autocorrection doesn't work for this method:
func initialLayoutAttributesForAppearingItem(at itemIndexPath: IndexPath) -> UICollectionViewLayoutAttributes?