So at first I wanted to get rid of the Navigation bar from the home screen as it does not want to show the title & I don't really need it.
However I can't remove it because I use NavigationLink. So I am left in a little pickle.
How do I either hide the toolbar/navigation bar on home page or show the title.
MIN CODE
struct ContentView: View {
var body: some View {
NavigationView {
Text("Loading")
}.navigationBarTitle(Text("Home"))
}
}
So after a few more attempts seems that the title had to be shown in
var body: some View {
NavigationView {
if posts.isEmpty {
Text("Loading")
//.navigationBarTitle("") //this must be empty
.navigationBarHidden(true)
} else {
(REST OF CODE)
}
}
}
Still can't hide it though. The issue is it keeps disappearing when the if statement runs.
The .navigationBarTitle, as well as other similar modifiers, should be used inside NavigationView, like
struct ContentView: View {
var body: some View {
NavigationView {
Text("Loading")
.navigationBarTitle(Text("Home")) // << here !!
}
}
}
Update: if you want to make modifier work for both condition branches wrap condition into some container (VStack, Group, etc.), like
var body: some View {
NavigationView {
Group {
if posts.isEmpty {
Text("Loading")
} else {
(REST OF CODE)
}
}
//.navigationBarTitle("") //this must be empty
.navigationBarHidden(true) // << here !!
}
}
Related
Still some what new to SwiftUI. Now I'm trying to present a sheet from a button in a Menu. I can reproduce the issue with the sample code below:
import SwiftUI
struct SheetView: View {
#Environment(\.presentationMode) var presentationMode
var body: some View {
Button("Press to dismiss") {
presentationMode.wrappedValue.dismiss()
}
.font(.title)
.padding()
.background(Color.black)
}
}
struct TestButtonInMenu: View {
#State private var showingSheet = false
var body: some View {
Button("Show Sheet") {
showingSheet.toggle()
}
.sheet(isPresented: $showingSheet) {
SheetView()
}
}
}
enum SampleEnum: String, CaseIterable {
case one, two, three, four
}
struct ContentView: View {
var body: some View {
Form {
Section {
VStack {
ForEach(SampleEnum.allCases, id:\.self) { id in
Menu("\(Text(id.rawValue))") {
TestButtonInMenu()
}
}
}
}
}
}
}
I've tried different sheet initializers but they don't make a difference.
What am I missing? Is this possible in SwiftUI?
You have a couple of problems with the code. First of all, in your ContentView you have the Menu inside of the ForEach. By doing it that way, you have created four menus with one button each, instead of one menu with four buttons. The point of Menu is to hide the buttons until they are needed.
The second issue is that you are trying to show one sheet off the button that is buried in another view in the menu. The sheet really should be declared in the parent, not a child, and I think you have confused the OS. That being said, I think eventually you intend to call four different sheets from the different buttons, and the answer Asperi pointed you to will help as you will be calling different sheets from the one .sheet. I corrected the code and just brought the button into the main UI and out of its own struct.
struct SheetView: View {
#Environment(\.presentationMode) var presentationMode
var body: some View {
Button("Press to dismiss") {
presentationMode.wrappedValue.dismiss()
}
.font(.title)
.padding()
.background(Color.black)
}
}
enum SampleEnum: String, CaseIterable {
case one, two, three, four
}
struct ContentView: View {
#State private var showingSheet = false
var body: some View {
Form {
Section {
VStack {
Menu("Show Sheet") {
ForEach(SampleEnum.allCases, id:\.self) { id in
Button(id.rawValue) {
showingSheet.toggle()
}
}
}
}
}
}
.sheet(isPresented: $showingSheet) {
SheetView()
}
}
}
I was taking a look at this :
tornadofx
and tried to expand on it with database connection and little more options, (not all of them make sense, but its just playing in a sandbox).
Even though table can be directly edited and the data will persist in database, i did try to do edit through text fields too. actual table editing would happen through different view and not table itself, as i said its just example.
Database used is Jetbrains Exposed.
object Categories : IntIdTable() {
val name = varchar("name", 64).uniqueIndex()
val description = varchar("description", 128)
}
class Category(id: EntityID<Int>) : IntEntity(id) {
companion object : IntEntityClass<Category>(Categories)
var name by Categories.name
var description by Categories.description
override fun toString(): String {
return "Category(name=\"$name\", description=\"$description\")"
}
}
now controller looks something like this, functions are just rudimentary and picked as an example.
typealias ModelToDirtyState = Map.Entry<CategoryModel, TableColumnDirtyState<CategoryModel>>
class CategoryModel() : ItemViewModel<Category>() {
val name: SimpleStringProperty = bind(Category::name)
val description: SimpleStringProperty = bind(Category::description)
}
class DBController : Controller() {
val categories: ObservableList<CategoryModel> by lazy {
transaction {
SchemaUtils.create(Categories)
Category.all().map {
CategoryModel().apply {
item = it
}
}.observable()
}
}
init {
Database.connect(
"jdbc:mysql://localhost:3306/test", driver = "com.mysql.cj.jdbc.Driver",
user = "test", password = "test"
)
TransactionManager.manager.defaultIsolationLevel = Connection.TRANSACTION_SERIALIZABLE
}
fun deleteCategory(model: CategoryModel) {
runAsync {
transaction {
model.item.delete()
}
}
categories.remove(model)
}
fun updateCategory(model: CategoryModel) {
transaction {
Categories.update {
model.commit()
}
}
}
fun commitDirty(modelDirtyMappings: Sequence<ModelToDirtyState>) {
transaction {
modelDirtyMappings.filter { it.value.isDirty }.forEach {
it.key.commit()
println(it.key)// commit value to database
it.value.commit() // clear dirty state
}
}
}
Just to quickly comment on controller, delete method works as "intended" however the update one does not, it does not work in sense that after using delete item is remove both from database and tableview(underlying list) itself, and when i do update its not, now i know the reason, i call remove manually on both database and list, now for update perhaps i could do change listener, or maybe tornadofx can do this for me, i just cant set it up to do it. Following code will make things clearer i think.
class CategoryEditor : View("Categories") {
val categoryModel: CategoryModel by inject()
val dbController: DBController by inject()
var categoryTable: TableViewEditModel<CategoryModel> by singleAssign()
var categories: ObservableList<CategoryModel> by singleAssign()
override val root = borderpane {
categories = dbController.categories
center = vbox {
buttonbar {
button("Commit") {
action {
dbController.commitDirty(categoryTable.items.asSequence())
}
}
button("Roll;back") {
action {
categoryTable.rollback()
}
}
// This model only works when i use categorytable.tableview.selected item, if i use categoryModel, list gets updated but not the view itself
// Question #1 how to use just categoryModel variable without need to use categorytable.tableview.selecteditem
button("Delete ") {
action {
val model = categoryTable.tableView.selectedItem
when (model) {
null -> return#action
else -> dbController.deleteCategory(model)
}
}
}
//And here no matter what i did i could not make the view update
button("Update") {
action {
when (categoryModel) {
null -> return#action
else -> dbController.updateCategory(categoryModel)
}
categoryTable.tableView.refresh()
}
}
}
tableview<CategoryModel> {
categoryTable = editModel
items = categories
enableCellEditing()
enableDirtyTracking()
onUserSelect() {
//open a dialog
}
//DOES WORK
categoryModel.rebindOnChange(this) { selectedItem ->
item = selectedItem?.item ?: CategoryModel().item
}
// Question #2. why bindSelected does not work, and i have to do it like above
//DOES NOT WORK
// bindSelected(categoryModel)
//
column("Name", CategoryModel::name).makeEditable()
column("Description", CategoryModel::description).makeEditable()
}
}
right = form {
fieldset {
field("Name") {
textfield(categoryModel.name)
}
}
fieldset {
field("Description") {
textfield(categoryModel.description)
}
}
button("ADD CATEGORY") {
action {
dbController.addCategory(categoryModel.name.value, categoryModel.description.value)
}
}
}
}
}
I apologize for huge amount of code, also in last code snipped i left questions in form of comments where i fail to achive desired results.
I am sure i am not properly binding code, i just dont see why, also i sometimes use one variable to update data, my declared one "categoryModel" and sometimes i use tableview.selecteditem, it just seems hacky and i cant seem to grasp way.
Thank you!
How can I change navigationBarBackButton color in SwiftUI? (by
default it's blue)
How can I change navigationBarBackButton text in SwiftUI?
This is my code (an example):
struct ExercisesList : View {
var exercises : [Exercise]
var body: some View {
NavigationView {
List(self.exercises.identified(by: \.number)) {exercise in
NavigationLink(destination: ExerciseDetailView(exercise: exercise)) {
ExerciseRow(exercisE: exercise)
}
}
.navigationBarTitle(Text("Exercises"))
}
}
}
By default, the navigationBarBackButton in "ExerciseDetailView" has a text of Exercise and color of blue.
My question is how can I manipulate these two?
Here is a solution. Hope it will help. In this way, you can use custom UIColor also.
struct ExercisesList : View {
var exercises : [Exercise]
var body: some View {
UINavigationBar.appearance().tintColor = UIColor.red
return NavigationView {
List(self.exercises.identified(by: \.number)) { exercise in
NavigationLink(destination: ExerciseDetailView(exercise: exercise)) {
ExerciseRow(exercisE: exercise)
}
}
}
.navigationBarTitle(Text("Exercises"))
}
}
Currently, No direct methods are available for that(XCode 11 beta 3).
However You can use UINavigationBar method for that,
see below code :
struct ExercisesList : View {
var exercises : [Exercise]
init() {
//navigationBarBackButton color will change//
UINavigationBar.appearance().tintColor = .purple
// you can also set backgroundColor//
UINavigationBar.appearance().backgroundColor = .white
}
var body: some View {
NavigationView {
List(self.exercises.identified(by: \.number)) {exercise in
NavigationLink(destination: ExerciseDetailView(exercise: exercise)) {
ExerciseRow(exercisE: exercise)
}
}
.navigationBarTitle(Text("Exercises"))
}
}
}
In this qml code:
Component {
id: userdelegate
PictureBox {
...
icon: model.icon
icon.heigth: 50
}
}
PictureBox comes from the PictureBox.qml system file in this way:
...
Image {
id: icon
...
width: parent.width; height: 150
}
Running qml, I have the error in the title.
I need to use PictureBox.qml, but I can't change it.
How can I override default height value for PictureBox.qml icon?
You can try to bypass QML's scoping rules by traversing Item children until you can find the Image and manipulate it directly. It's possible it could break in the future, but item.toString() gives you something useful:
item.toString() -> "QQuickImage(0x114054350)"
So, you can try something like this (not tested):
function findItemOfType(type, item) {
if (item.toString().indexOf(type) != -1) {
return child;
}
for (var i=0;i < children.length;++i) {
var child = children[i];
var result = findItemOfType(type, child.children);
if (result != null) {
return result;
}
}
return null;
}
Using it like this:
findItemOfType("QQuickImage", pictureBoxId);
I need to traverse a tree with an unknown number of nodes by making asynchronous URL requests. My current approach looks like this:
class Parent {
var foo: String
var id: Int
var children: [Child]?
func loadChildren() {
for child in self.children {
self.getAllChildren(child)
}
}
func getAllChildren(current: Child) {
current.load() {(success) in
if (success) {
if let children = current.children {
for child in children {
self.getAllChildren(child)
}
}
}
}
}
}
class Child {
var bar: String
var id: Int
var children: [Child]?
func load(success: (Bool) -> ()) {
// Load from API and initalize values
}
}
The problem with my current approach above is that I don't known when the loading has finished. I don't care if some children fail to load, but i need to make UI updates when all children (and their children) of an parent have been loaded.
I looked into various approaches like promises and dispatch groups but i'm struggling to get it work. I'm using Swift 2 and ideally the parent would have a function like this:
func loadChildren(success: (Bool) -> ()) {
// do stuff
}