class FilePicker

A FilePicker class encapsulates a file picker box.

class FilePicker : public Window, public LinkTarget<FilePicker>, public Completable<FilePicker>

FilePicker::GetFileNameCount	Returns the number of files that are currently selected.
FilePicker::GetFileName	Returns the name of the file that is currently selected.

FilePicker(const char *title, const char *directory, uint32 flags = 0, const char *panel = nullptr);

title	The file picker's displayed title.
directory	The path to the directory that is initially displayed by the file picker.
flags	Flags that affect the appearance and behavior of the file picker. See below for a list of possible values.
panel	The name of the panel resource to use for the picker dialog. To use the default file picker, this should be set to nullptr.

The FilePicker class provides a standard interface for selecting files. When the user selects a file, the file picker's completion callback is called. The completion callback can then retrieve the path to the selected file by calling the FilePicker::GetFileName function.

Options that control the appearance and behavior of the file picker can be controlled by specifying a combination (through logical OR) of the following constants in the flags parameter.

kFilePickerSave	Display an editable text field where the file name can be typed in.
kFilePickerMultipleSelection	Allow multiple files to be selected in the file list simultaneously. This should not be set if the kFilePickerSave flag is set.
kFilePickerEnableRootDirectory	Causes the root directory name to be included in the file name. If the kFilePickerSave flag is set, then this flag also allows a file to be specified in the root directory.
kFilePickerStayInsideRootDirectory	Don't allow navigation outside (above) the root directory.

The directory parameter specifies the directory for which a list of files is initially displayed. If the kFilePickerNoDirectories flag is not specified, then the user can navigate to any directory beneath the initial directory. If the kFilePickerSubdirectory flag is specified, the user can also navigate upward one level from the initial directory (and subsequently to any directory beneath that level).

If the kFilePickerSave flag is specified, then an editable text box is displayed in which the user can enter a file name. This is useful for allowing new files to be created.

If the file picker is cancelled, then the completion callback is not called.

Window	The FilePicker class is a specific type of window.
LinkTarget<FilePicker>	File pickers support smart linking with the Link class.
Completable<FilePicker>	The completion callback is called when the file picker is dismissed.