# Native dialogs support

These functions are declared in the following header file.
Link with allegro_dialog.

~~~~c
 #include <allegro5/allegro_native_dialog.h>
~~~~

## API: ALLEGRO_FILECHOOSER

Opaque handle to a native file dialog.

## API: ALLEGRO_TEXTLOG

Opaque handle to a text log window.

## API: al_init_native_dialog_addon

Initialise the native dialog addon.

Returns true on success, false on error.

Since: 5.0.9, 5.1.0

> *Note:* Prior to Allegro 5.1.0 native dialog functions could be called
without explicit initialisation, but that is now deprecated.
Future functionality may require explicit initialisation.
An exception is [al_show_native_message_box], which may be useful to show
an error message if Allegro fails to initialise.

See also: [al_shutdown_native_dialog_addon]

## API: al_shutdown_native_dialog_addon

Shut down the native dialog addon.

Since: 5.0.9, 5.1.5

See also: [al_init_native_dialog_addon]

## API: al_create_native_file_dialog

Creates a new native file dialog.  You should only have one such dialog opened
at a time.

Parameters:

- initial_path: The initial search path and filename. Can be NULL.
  To start with a blank file name the string should end with a directory
  separator (this should be the common case).

- title: Title of the dialog.

- patterns: A list of semi-colon separated patterns to match. You
  should always include the pattern "\*.*" as usually the MIME type
  and not the file pattern is relevant. If no file patterns are
  supported by the native dialog, this parameter is ignored.

- mode: 0, or a combination of the flags below.

Possible flags for the 'flags' parameter are:

ALLEGRO_FILECHOOSER_FILE_MUST_EXIST
:   If supported by the native dialog, it will not allow entering new names,
    but just allow existing files to be selected. Else it is ignored.
ALLEGRO_FILECHOOSER_SAVE
:   If the native dialog system has a different dialog for saving (for example
    one which allows creating new directories), it is used. Else ignored.
ALLEGRO_FILECHOOSER_FOLDER
:   If there is support for a separate dialog to select a folder instead of a
    file, it will be used.
ALLEGRO_FILECHOOSER_PICTURES
:   If a different dialog is available for selecting pictures, it is used. Else
    ignored.
ALLEGRO_FILECHOOSER_SHOW_HIDDEN
:   If the platform supports it, also hidden files will be shown.
ALLEGRO_FILECHOOSER_MULTIPLE
:   If supported, allow selecting multiple files.

Returns:

A handle to the dialog which you can pass to
[al_show_native_file_dialog] to display it, and from which you then can
query the results. When you are done, call
[al_destroy_native_file_dialog] on it.

If a dialog window could not be created then this function returns NULL.

## API: al_show_native_file_dialog

Show the dialog window.  The display may be NULL, otherwise the given display
is treated as the parent if possible.

This function blocks the calling thread until it returns,
so you may want to spawn a thread with [al_create_thread] and
call it from inside that thread.

Returns true on success, false on failure.

## API: al_get_native_file_dialog_count

Returns the number of files selected, or 0 if the dialog was cancelled.

## API: al_get_native_file_dialog_path

Returns one of the selected paths.

## API: al_destroy_native_file_dialog

Frees up all resources used by the file dialog.

## API: al_show_native_message_box

Show a native GUI message box. This can be used for example to display an error
message if creation of an initial display fails.  The display may be NULL,
otherwise the given display is treated as the parent if possible.

The message box will have a single "OK" button and use the style informative
dialog boxes usually have on the native system. If the `buttons` parameter is
not NULL, you can instead specify the button text in a string, with buttons
separated by a vertical bar (|).

ALLEGRO_MESSAGEBOX_WARN
:   The message is a warning.
    This may cause a different icon (or other effects).
ALLEGRO_MESSAGEBOX_ERROR
:   The message is an error.
ALLEGRO_MESSAGEBOX_QUESTION
:   The message is a question.
ALLEGRO_MESSAGEBOX_OK_CANCEL
:   Instead of the "OK" button also display a cancel button.
    Ignored if `buttons` is not NULL.
ALLEGRO_MESSAGEBOX_YES_NO
:   Instead of the "OK" button display Yes/No buttons.
    Ignored if `buttons` is not NULL.

[al_show_native_message_box] may be called without Allegro being installed.
This is useful to report an error to initialise Allegro itself.

Returns:

- 0 if the dialog window was closed without activating a button.
- 1 if the OK or Yes button was pressed.
- 2 if the Cancel or No button was pressed.

If `buttons` is not NULL, the number of the pressed button is returned, starting
with 1.

If a message box could not be created then this returns 0, as if the window
was dismissed without activating a button.

Example:

~~~~c
int button = al_show_native_message_box(
  display,
  "Warning",
  "Are you sure?",
  "If you click yes then you are confirming that \"Yes\""
  "is your response to the query which you have"
  "generated by the action you took to open this"
  "message box.",
  NULL,
  ALLEGRO_MESSAGEBOX_YES_NO
);
~~~~

## API: al_open_native_text_log

Opens a window to which you can append log messages with
[al_append_native_text_log]. This can be useful for debugging if you don't
want to depend on a console being available.

Use [al_close_native_text_log] to close the window again.

The flags available are:

ALLEGRO_TEXTLOG_NO_CLOSE
:   Prevent the window from having a close button. Otherwise if the close
    button is pressed an event is generated; see
    [al_get_native_text_log_event_source].

ALLEGRO_TEXTLOG_MONOSPACE
:   Use a monospace font to display the text.

Returns NULL if there was an error opening the window, or if text log windows
are not implemented on the platform.

See also: [al_append_native_text_log], [al_close_native_text_log]

## API: al_close_native_text_log

Closes a message log window opened with [al_open_native_text_log]
earlier.

Does nothing if passed NULL.

See also: [al_open_native_text_log]

## API: al_append_native_text_log

Appends a line of text to the message log window and scrolls to the
bottom (if the line would not be visible otherwise). This works like
printf. A line is continued until you add a newline character.

If the window is NULL then this function will fall back to calling
printf. This makes it convenient to support logging to a window or
a terminal.

## API: al_get_native_text_log_event_source

Get an event source for a text log window. The possible events are:

ALLEGRO_EVENT_NATIVE_DIALOG_CLOSE
:   The window was requested to be closed, either by pressing the close button
    or pressing Escape on the keyboard.
    The user.data1 field will hold a pointer to the [ALLEGRO_TEXTLOG]
    which generated the event.
    The user.data2 field will be 1 if the event was generated as a result of a
    key press; otherwise it will be zero.

## API: al_get_allegro_native_dialog_version

Returns the (compiled) version of the addon, in the same format as
[al_get_allegro_version].
