Allow customizing native dialog flags on Windows

[SageMik]

Hi, I want native dialog flags (e.g. FOS_FORCEFILESYSTEM ) for the file and directory pickers on Windows, but I don't see a public way to do that:

FileKit/filekit-dialogs/src/jvmMain/kotlin/io/github/vinceglb/filekit/dialogs/platform/windows/WindowsFilePicker.kt

Lines 111 to 112 in 9d95c48

	// Add in FOS_PICKFOLDERS which hides files and only allows selection of folders
	fileOpenDialog.setFlag(FOS_PICKFOLDERS)

Would you consider adding support for this?

Thanks!

[vinceglb]

Hi @SageMik, thanks for opening this issue!

I took a closer look at FOS_FORCEFILESYSTEM. Since FileKit returns filesystem-backed PlatformFile values, this flag should be enforced internally rather than configured.

I opened #613 to apply it consistently to every JVM Windows dialog. The Kotlin/Native Windows implementation already applied it.

For the broader customization request, which other flags would you like to configure, and for which picker use cases? This will help me design the API without exposing incompatible options.

[SageMik]

Thanks for your response! For now, I'm only using FOS_FORCEFILESYSTEM, but would changing the existing default behavior be ideal? As I originally envisioned, maybe it's more flexible to provide something like FileKitMacOSSettings?

FileKit/filekit-dialogs/src/jvmMain/kotlin/io/github/vinceglb/filekit/dialogs/FileKitDialogSettings.jvm.kt

Lines 12 to 23 in ad85054

	public actual data class FileKitDialogSettings(
	public val title: String? = null,
	public val parentWindow: Window? = null,
	public val macOS: FileKitMacOSSettings = FileKitMacOSSettings(),
	) {
	public actual companion object {
	/**
	* Creates a default instance of [FileKitDialogSettings].
	*/
	public actual fun createDefault(): FileKitDialogSettings = FileKitDialogSettings()
	}
	}

[vinceglb]

Thanks for the clarification!

In this case, I prefer to keep FOS_FORCEFILESYSTEM as the default behavior. Windows dialogs can otherwise return virtual Shell items that do not have a usable filesystem path, while FileKit’s PlatformFile API is designed to represent real files and directories.

Enforcing this flag ensures that every selected item can be safely returned and used as a PlatformFile. It also keeps the JVM and Kotlin/Native Windows implementations consistent.

A FileKitWindowsSettings API could make sense if concrete use cases for other compatible flags come up, but I would rather avoid adding new public API before we have one.

Since #613 addresses your current use case, I think we can keep the current implementation for now