Hello. I have written a UI in scala using scalafx. However, when constructing the UI elements,I initalize a scrollPanel that I’m storing photos in as blank,and I’m unable to pass in a image from another function. How can I pass a image to populate the scrollPanel from another function. I have the code displayed below.
import scalafx.application.JFXApp
import scalafx.scene.Scene
import scalafx.scene.control.{Menu, MenuBar, MenuItem, ScrollPane}
import scalafx.scene.image.{Image, ImageView}
import scalafx.stage.Stage
import scalafx.stage.FileChooser
import scalafx.scene.layout.{VBox, HBox, StackPane, Region}
import java.io.File
object DropdownMenuApp extends JFXApp {
val vbox = new VBox()
stage = new JFXApp.PrimaryStage {
title = "ScalaFX Dropdown Menu Example"
scene = new Scene {
content = new VBox(){
children = Seq(
createMenuBar(),
createScrollPane()
)
}
}
}
def createMenuBar(): MenuBar = {
val fileMenu = new Menu("File")
val openItem = new MenuItem("Open")
val saveItem = new MenuItem("Save")
fileMenu.items = Seq(openItem, saveItem)
val editMenu = new Menu("Edit")
val cutItem = new MenuItem("Cut")
val copyItem = new MenuItem("Copy")
val pasteItem = new MenuItem("Paste")
editMenu.items = Seq(cutItem, copyItem, pasteItem)
val menuBar = new MenuBar()
menuBar.menus = Seq(fileMenu, editMenu)
openItem.setOnAction(_ => openFile())
menuBar
}
def createScrollPane(): ScrollPane = {
val imageView = new ImageView()
val stackPane = new StackPane()
stackPane.children = Seq(imageView)
val scrollPane = new ScrollPane()
scrollPane.content = stackPane
scrollPane.hbarPolicy = ScrollPane.ScrollBarPolicy.AsNeeded
scrollPane.vbarPolicy = ScrollPane.ScrollBarPolicy.AsNeeded
scrollPane
}
def openFile(): Unit ={ //Trying to populate the scroll panel once openFile is called.
val fileChooser = new FileChooser()
fileChooser.title = "Open File"
val extensionFilter = new FileChooser.ExtensionFilter("Supported Files", Seq("*.zip", "*.rar"))
fileChooser.extensionFilters.add(extensionFilter)
val selectedFile = fileChooser.showOpenDialog(stage)
if (selectedFile != null){
val filePath = selectedFile.getAbsolutePath()
//print(filePath)
val folderpath = FileHandling.analyzeFile(filePath)
print(folderpath)
val files: Array[File] = folderpath.listFiles()
val firstFile = files.head
val imagePath = firstFile.toURI.toString
val image = new Image(imagePath)
val imageView = new ImageView(image)
}
}
}
From what little [Scala|Java]FX experience I have, I’d expect this to work via bindings, and the image in (ScalaFX) ImageView is exposed as a (JavaFX) ObjectProperty, indeed.
You need to pass the image to ImageView that is part of the UI. In your code you create an ImageView as a local variable in openFile()) You have another Image ImageView that is assigned to the UI in createScrollPane().
You could create a single ImageView that is a member of object DropdownMenuApp and then use that in both createScrollPane() and openFile().
Here is a corrected code:
import scalafx.application.JFXApp
import scalafx.scene.Scene
import scalafx.scene.control.{Menu, MenuBar, MenuItem, ScrollPane}
import scalafx.scene.image.{Image, ImageView}
import scalafx.scene.layout.{StackPane, VBox}
import scalafx.stage.FileChooser
object DropdownMenuApp extends JFXApp {
val imageView = new ImageView()
val vbox = new VBox()
stage = new JFXApp.PrimaryStage {
title = "ScalaFX Dropdown Menu Example"
scene = new Scene {
content = new VBox() {
children = Seq(
createMenuBar(),
createScrollPane()
)
}
}
}
def createMenuBar(): MenuBar = {
val fileMenu = new Menu("File")
val openItem = new MenuItem("Open")
val saveItem = new MenuItem("Save")
fileMenu.items = Seq(openItem, saveItem)
val editMenu = new Menu("Edit")
val cutItem = new MenuItem("Cut")
val copyItem = new MenuItem("Copy")
val pasteItem = new MenuItem("Paste")
editMenu.items = Seq(cutItem, copyItem, pasteItem)
val menuBar = new MenuBar()
menuBar.menus = Seq(fileMenu, editMenu)
openItem.setOnAction(_ => openFile())
menuBar
}
def createScrollPane(): ScrollPane = {
val stackPane = new StackPane()
stackPane.children = Seq(imageView)
val scrollPane = new ScrollPane()
scrollPane.content = stackPane
scrollPane.hbarPolicy = ScrollPane.ScrollBarPolicy.AsNeeded
scrollPane.vbarPolicy = ScrollPane.ScrollBarPolicy.AsNeeded
scrollPane
}
def openFile(): Unit = { // Trying to populate the scroll panel once openFile is called.
val fileChooser = new FileChooser()
fileChooser.title = "Open File"
val extensionFilter = new FileChooser.ExtensionFilter("Supported Files", Seq("*.jpg", "*.png"))
fileChooser.extensionFilters.add(extensionFilter)
val selectedFile = fileChooser.showOpenDialog(stage)
if (selectedFile != null) {
val firstFile = selectedFile
val imagePath = firstFile.toURI.toString
val image = new Image(imagePath)
imageView.image = image
}
}
}
It looks like you’re working on a ScalaFX project and you’re facing an issue with populating a ScrollPane with an image when a file is opened. This is a common challenge for mobile app developers in Florida who often work with dynamic UI elements.
In your openFile() function, you’re creating a new ImageView instance, but it’s not the same instance that you added to your ScrollPane in the createScrollPane() function. To update the ImageView inside the ScrollPane, you need to make sure you’re working with the same instance.
Here’s how you can modify your code to achieve this:
Declare imageView as a member variable so that it can be accessed from both createScrollPane() and openFile().
scala
object DropdownMenuApp extends JFXApp {
val imageView = new ImageView() // Declare imageView here
...
}
Update the imageView in your openFile() function.
scalaCopy code
def openFile(): Unit = {
...
if (selectedFile != null) {
...
val image = new Image(imagePath)
imageView.image = image // Update the imageView here
}
}
By doing this, you’re updating the same ImageView instance that you added to your ScrollPane, and the image should now display correctly.