Open with default app

Open a file in the app the system associates with its type, such as a PDF viewer

Hand a file to the app the system associates with its type: a PDF viewer for .pdf, an image viewer for .jpg. Your app doesn’t read the content. The function is not available on the web, so call it from a non-web source set such as nonWebMain (see shared source sets).

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Usage

openFileWithDefaultApplication is a regular function, not a suspend function, so you can call it directly from a click handler. There is no Compose launcher.

val file = FileKit.filesDir / "report.pdf"
FileKit.openFileWithDefaultApplication(file)

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Options

file · PlatformFile · required

The file to open. It must exist.

openFileSettings · FileKitOpenFileSettings · default: "createDefault()"

Platform-specific settings.

Show properties

authority · String? · default: "null" · Android

FileProvider authority, only needed for files outside filesDir and cacheDir. When null, FileKit uses its bundled ${applicationId}.FileKitFileProvider. See Android setup.

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Platform notes

Failures are reported differently on each platform. Only the JVM wraps some of them in FileKitDialogException:

Platform	Behavior
Android	Sends an ACTION_VIEW intent with the MIME type of the file extension. Throws ActivityNotFoundException when no app handles that type, and IllegalArgumentException for a file outside the directories its FileProvider covers.
iOS	Calls openURL. If that fails, shows the “Open in” menu (UIDocumentInteractionController) so the user can pick an app. Reports no error.
macOS	Uses NSWorkspace. Reports no error.
JVM	Uses java.awt.Desktop.open when the desktop supports opening files. Otherwise (headless setups, Linux without GNOME libraries), on Linux it falls back to xdg-open and waits up to half a second for it to report an error. Throws FileKitDialogException when neither works: Desktop cannot open files and xdg-open is missing, cannot start, or exits with an error code. Errors from Desktop.open itself are not wrapped, such as IOException when no app is associated.
Linux native	Starts xdg-open without waiting for it. Throws FileKitException only if the process cannot start.
Windows native	Calls ShellExecuteW with the open verb. Reports no error.
Web	Not available.

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Android setup

Only needed for files outside FileKit.filesDir and FileKit.cacheDir. filekit-dialogs already ships a FileProvider (${applicationId}.FileKitFileProvider) that covers those two directories, and content:// files returned by the pickers need no provider at all. For any other location, such as getExternalFilesDir(), FileProvider throws an IllegalArgumentException until you declare your own provider.

1. Declare a provider in your manifest

   AndroidManifest.xml

   <provider
       android:name="androidx.core.content.FileProvider"
       android:authorities="${applicationId}.fileprovider"
       android:exported="false"
       android:grantUriPermissions="true">
       <meta-data
           android:name="android.support.FILE_PROVIDER_PATHS"
           android:resource="@xml/file_paths" />
   </provider>
   
2. List the directories it may expose

   Add one entry per location you use, for example app-specific external storage:

   res/xml/file_paths.xml

   <paths>
       <external-files-path name="external_files" path="." />
   </paths>
   

   See FileProvider for every path type.

3. Pass the authority to FileKit

   The authority parameter exists only on Android, so build these settings in androidMain:

   androidMain

   val authority = "${FileKit.context.packageName}.fileprovider"
   
   FileKitOpenCameraSettings(authority = authority) // camera picker
   FileKitShareSettings(authority = authority) // share file
   FileKitOpenFileSettings(authority = authority) // open with default app
   

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Related

• Share file to send a file to another app.
• File picker to let the user choose one.