FILES.md

Files

Table of Contents

1. Gradle Dependency
2. File Choosers
   1. Basics
   2. Filter
   3. Empty Text
   4. Folder Creation
3. Folder Choosers
   1. Basics
   2. Filter
   3. Empty Text
   4. Folder Creation

Gradle Dependency

The files module contains extensions to the core module, such as a file and folder chooser.

dependencies {
  ...
  implementation 'com.afollestad.material-dialogs:files:3.1.1'
}

File Choosers

Basics

Note: File choosers require your app to have permission to READ_EXTERNAL_STORAGE, otherwise directory listings will come back empty.

You create file choosers using the fileChooser extension on MaterialDialog:

MaterialDialog(this).show {
  fileChooser { dialog, file ->
      // File selected
  }
}

It shows all files and folders, starting in the external storage directory. Tapping a file invokes the callback and dismisses the dialog.

You can change the directory which is listed initially:

val initialFolder = File(getExternalStorageDirectory(), "Download")

MaterialDialog(this).show {
  fileChooser(initialDirectory = initialFolder) { dialog, file ->
      // File selected
  }
}

If a positive action button exists, tapping a file will select it, but the callback isn't invoked until the positive action button is pressed.

Filter

A filter can be applied to only show the files and directories you wish to show:

// show ALL folders, and files that start with the letter 'a'
val myFilter: FileFilter = { it.isDirectory || it.nameWithoutExtension.startsWith("a", true) }

MaterialDialog(this).show {
  fileChooser(filter = myFilter) { dialog, file ->
      // File selected
  }
}

Empty Text

Empty text is shown when a folder has no contents. You can configure the empty text label:

MaterialDialog(this).show {
  fileChooser(emptyTextRes = R.string.custom_label) { dialog, file ->
      // File selected
  }
}

Folder Creation

You can allow your users to create folders.

MaterialDialog(this).show {
  fileChooser(
      allowFolderCreation = true,
      folderCreationLabel = R.string.new_folder // optional as well
  ) { dialog, file -> 
      // File selected
  }
}

This "New Folder" option is only show in directories which are writable.

Folder Choosers

Note: Folder choosers require your app to have permission to READ_EXTERNAL_STORAGE, otherwise directory listings will come back empty.

Folder choosers are basically the same as file choosers, with a few minor differences: 1) only folders are shown, even when a custom filter is applied. 2) the selection callback is never invoked on a item click, it only gets invoked with the currently viewed folder when the positive action button is pressed.

Basics

MaterialDialog(this).show {
  folderChooser { dialog, folder ->
      // Folder selected
  }
}

Filter

You can apply a filter like you can with the file chooser.

// show only folders that start with the letter 'a'
val myFilter: FileFilter = { it.name.startsWith("a", true) }

MaterialDialog(this).show {
  folderChooser(filter = myFilter) { dialog, file ->
      // Folder selected
  }
}

Empty Text

Empty text is shown when a folder has no contents. You can configure the empty text label:

MaterialDialog(this).show {
  folderChooser(emptyTextRes = R.string.custom_label) { dialog, file ->
      // File selected
  }
}

Folder Creation

You can allow your users to create folders.

MaterialDialog(this).show {
  folderChooser(
      allowFolderCreation = true,
      folderCreationLabel = R.string.new_folder // optional as well
  ) { dialog, file -> 
      // File selected
  }
}

This "New Folder" option is only show in directories which are writable.