Picture function draws picture out of resource id; like R.drawable.icon.
#Composable
fun Picture(#DrawableRes resId: Int, modifier: Modifier = Modifier) {
val rectModifier = loadVectorResource(resId).resource.resource
?.let { asset ->
modifier.paint(
painter = VectorPainter(asset)
)
}
?: modifier
Box(modifier = rectModifier)
}
How can I change this, so it takes a Drawable argument instead of an #DrawableRes?
I am not sure about your scenario, to which you need Drawable instead of the given API.
But we can achieve using the following way. Modifier.paint need just a Painter Object, Painter we can create using both ImagePainter and VectorPainter.
In our case, we want to use Drawable, so we can use ImagePainter and its need ImageAsset, so we can use Bitmap to create ImageAsset.
So the final result will be like:
#Composable
fun Picture(#DrawableRes resId: Int, modifier: Modifier = Modifier) {
val resources = ResourcesCompat.getDrawable(ContextAmbient.current.resources, resId, null)
resources?.let {
Picture(drawable = it, modifier = modifier)
}
}
#Composable
fun Picture(drawable: Drawable, modifier: Modifier = Modifier) {
Box(
modifier = modifier.paint(
ImagePainter(
drawable.toBitmap().asImageAsset()
)
)
)
}
Related
I cannot figure out how to replace setTargetFragment() in the code sample below, which is from my Preferencesfragment obviously:
override fun onPreferenceStartFragment(
caller: PreferenceFragmentCompat,
pref: Preference
): Boolean {
// Instantiate the new Fragment
val args = pref.extras
val fragment = supportFragmentManager.fragmentFactory.instantiate(
classLoader,
pref.fragment
).apply {
arguments = args
setTargetFragment(caller, 0) // <-- DEPRICATED CODE
}
// Replace the existing Fragment with the new Fragment
supportFragmentManager.beginTransaction()
.replace(R.id.settings, fragment)
.addToBackStack(null)
.commit()
title = pref.title
return true
}
Too many unknowns for my level of knowledge of Android Studio! This reference helps, but still confused:
How to replace setTargetFragment() now that it is deprecated
Well, apparently this works, but I'm not sure that I really understand what is going on:
override fun onPreferenceStartFragment(
caller: PreferenceFragmentCompat,
pref: Preference
): Boolean {
// Instantiate the new Fragment
val args = pref.extras
val fragment: Fragment = supportFragmentManager.fragmentFactory.instantiate(classLoader, pref.fragment)
fragment.arguments = args
supportFragmentManager.beginTransaction().replace(R.id.settings, fragment).addToBackStack(null).commit()
supportFragmentManager.setFragmentResultListener("requestKey", fragment) { _, _ -> }
return true
}
How to make a search field to insert the result in a LazyColumn
My code:
#Composable
private fun SearchTopBar(){
TopAppBar(title={ },
navigationIcon = {
IconButton(onClick = { onBackPressed() }) {
Icon(imageVector = Icons.Default.ArrowBack, contentDescription = stringResource(
id = R.string.back
),tint= colorResource(id = R.color.black) )
}
},
contentColor = Color.White,
backgroundColor = colorResource(id = R.color.pastel_green),
actions = {
TextField()
}
)
}
#Composable
private fun Main(){
Scaffold(topBar={SearchTopBar()},content={})
}
Dynamically change the content the search that comes from the api
I would introduce a ViewModel with two states:
val query: StateFlow<String>
val items: StateFlow<T>
Then use the stateHoisting pattern with the value, onValueChanged to modify your query.
Your items should observe your query in the viewModel and update the items.
And you could again observe the result items in your Composable with viewModel.items.collectAsState()
See this example for more information
I am trying to add dynamic properties to an object and have flow type check them:
my function would be like this:
function defineStuff(obj:MyType, keys:string[]):??? {
keys.forEach(function(key) {
Object.defineProperty(obj, key, {get:function(){....}});
obj["Add"+key] = function(value) {....};
obj["Remove"+key] = function(value) {....};
}
return obj;
}
I would like to be able to do stuff like this;
var obj : MyType = fetchMyObj();
defineStuff(obj, ["Thing", "OtherThing"]);
var thing = obj.Thing;
obj.AddOtherThing(10);
all dynamic properties type would be number
is there a syntax for doing this in flow? (i.e. how to fill the ???)
This should work for dictionaries.
type MyType = {[key: string]: number};
// ...
function defineStuff(obj: MyType, keys:string[]): MyType {
keys.forEach(function(key) {
Object.defineProperty(obj, key, {get:function(){....}});
// you can't have functions here, because you say that all values should be numbers
// obj["Add"+key] = function(value) {....};
// obj["Remove"+key] = function(value) {....};
}
return obj;
}
// ...
See docs
I'm using TornadoFX 1.7.5 and I can't seem to get bound properties to work. I have the below ItemViewModels
class DynamicMenuViewModel : ItemViewModel<DynamicMenu>(DynamicMenu()) {
val title = bind { item?.title?.toProperty() }
val isBold = bind { item?.isBold?.toProperty() }
val routes = bind { item?.routes?.toProperty() }
}
data class DynamicMenu(var title: String = "", var isBold: Boolean = false, var routes: MutableList<MenuRouteViewModel> = mutableListOf())
class MenuRouteViewModel : ItemViewModel<MenuRoute>(MenuRoute()) {
val url = bind { item?.url?.toProperty() }
val title = bind { item?.title?.toProperty() }
val isBold = bind { item?.isBold?.toProperty() }
val showNew = bind { item?.showNew?.toProperty() }
}
data class MenuRoute(var url: String = "", var title: String = "", var showNew: Boolean = false, var isBold: Boolean = false)
Which are bound like this:
//routesController.dynamicMenu is an instance of DynamicMenuViewModel()
textfield(property = routesController.dynamicMenu.title) {
prefWidth = formWidth * .5
gridpaneConstraints {
columnRowIndex(0, 1)
marginLeft = 10.0
columnSpan = 2
marginBottom = 20.0
}
}
checkbox(property = routesController.dynamicMenu.isBold){
gridpaneConstraints {
columnRowIndex(2, 1)
marginLeft = 15.0
marginBottom = 20.0
}
}
Then the following functions commit the models and prints them to the screen when I click a button:
fun onClick(){
commitModel()
println(dynamicMenu.item.toString())
dynamicMenu.item.routes.forEach {
println(it.item.toString())
}
}
fun commitModel(){
dynamicMenu.item.routes.forEach {
it.commit()
}
dynamicMenu.commit()
}
The problem is that when I run the program and edit the textfields and checkboxes then click the button that runs onClick(), the backing item doesn't seem to be getting updated. So none of the updated values are printed to the console.
What am I doing wrong here?
The ViewModel can as you probably know only bind bidirectionally against JavaFX Properties. Your domain objects doesn't contain JavaFX properties, so you need to convert them. However, the toProperty() function you are using only operates on a value, and turns it into a Property. This property has no way of knowing about it's field owner, and hence cannot write back into the domain object.
Luckily, you can use the observable function to make your domain object properties writable as well:
val url = bind { item?.observable(MenuRoute::url) }
Since the observable function operates on a specific instance of a MenuRoute object, it now has enough information to write back into that instance when you commit() the model.
If you would consider changing the properties in your domain objects to be observable, you could write:
val url = bind(MenuRoute::url)
You can use the TornadoFX IDEA plugin inspection "Convert all properties to TornadoFX Properties" to automatically rework your properties. This would transform your MenuRoute object into:
class MenuRoute {
val isBoldProperty = SimpleBooleanProperty(false)
var isBold by isBoldProperty
val showNewProperty = SimpleBooleanProperty(false)
var showNew by showNewProperty
val urlProperty = SimpleStringProperty("")
var url by urlProperty
val titleProperty = SimpleStringProperty("")
var title by titleProperty
}
(You have to manually remove the data modifier on your class. Also beware that the current version of the plugin has a bug in the conversion function that would leave the old parameters - a new version will be released shortly).
If you don't want to do that for various reasons, I was just able to support that nice syntax even for mutable vars like you have, so from TornadoFX 1.7.6 you can use this syntax in your binding statements even if you don't want to change your data classes:
val url = bind(MenuRoute::url)
I have the following function to access a property's delegate. It uses Kotlin reflection to get a property's name and Java reflection to get the field.
fun Any.getDelegate<T>(prop: KProperty<T>): Any {
return javaClass.getDeclaredField("${prop.name}\$delegate").let {
it.setAccessible(true)
it.get(this)
}
}
The method is used like this:
val delegate = a.getDelegate(A::b)
However, I would prefer to use it like this:
val delegate = a.b.delegate
The problem with the code above is getting the property name of a.b and getting the instance a from a.b. From what I know about Kotlin, this is probably not possible, however I'd like to see if I can clean up my function at all.
To give a bigger picture of what I'm trying do here's my complete code. I want an observable delegate to which I can add and remove observers using the delegate reference and without creating addition variables.
fun Any.addObservable<T>(prop: KProperty<T>, observer: (T) -> Unit) {
getObservableProperty(prop).observers.add(observer)
}
fun Any.getObservableProperty<T>(prop: KProperty<T>): ObservableProperty<T> {
return getDelegate(prop) as ObservableProperty<T>
}
fun Any.getDelegate<T>(prop: KProperty<T>): Any {
return javaClass.getDeclaredField("${prop.name}\$delegate").let {
it.setAccessible(true)
it.get(this)
}
}
class ObservableProperty<T>(
initialValue: T,
initialObservers: Array<(T) -> Unit> = emptyArray()) : ReadWriteProperty<Any?, T> {
private var value = initialValue
public val observers: MutableSet<(T) -> Unit> = initialObservers.toHashSet()
public override fun get(thisRef: Any?, desc: PropertyMetadata): T {
return value
}
public override fun set(thisRef: Any?, desc: PropertyMetadata, value: T) {
this.value = value
observers.forEach { it(value) }
}
}
class A() {
var b by ObservableProperty(0)
}
fun main(args: Array<String>) {
val a = A()
a.addObservable(A::b) {
println("b is now $it")
}
a.b = 1
a.b = 2
a.b = 3
}
Edit:
I just realized that the function also isn't strict because the property delegate field name is referenced by KProperty name, which doesn't require a strong reference to the enclosing class. Here's an example to demonstrate the problem:
class A() {
var foo by ObservableProperty(0)
}
class B() {
var foo by ObservableProperty(0)
}
fun main(args: Array<String>) {
val a = A()
a.addObservable(B::foo) {
println("b is now $it")
}
a.foo = 1
a.foo = 2
a.foo = 3
}
This compiles and runs without error because A::foo and B::foo both result in a field string of "foo$delegate.
Right now reflection is all we can do to get to the delegate object. We are designing a language feature to have direct access to delegate instance, but it's long way to go.
This is how you get the name of a Kotlin Property (although only with an instance of the class). This part will be useful to anyone arriving at this question purely based off its title.
class Stuff(val thing: String)
val stuff = Stuff("cool stuff")
val thingFieldName = "${stuff.thing}\$delegate"
// value of thingFieldName is now "thing"
In terms of getting the delegate itself easier, they say you can now do this:
class Foo {
var bar: String by ReactiveProperty<String>()
}
val foo = Foo()
val bar = foo.bar
val barDelegate = ... // foo.bar$delegate
See ticket.