Native dialogs support

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

 #include <allegro5/allegro_native_dialog.h>

ALLEGRO_FILECHOOSER

typedef struct ALLEGRO_FILECHOOSER ALLEGRO_FILECHOOSER;

Source Code

Opaque handle to a native file dialog.

Examples:

ex_native_filechooser.c

ALLEGRO_TEXTLOG

typedef struct ALLEGRO_TEXTLOG ALLEGRO_TEXTLOG;

Source Code

Opaque handle to a text log window.

Examples:

al_init_native_dialog_addon

bool al_init_native_dialog_addon(void)

Source Code

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.

Examples:

al_is_native_dialog_addon_initialized

bool al_is_native_dialog_addon_initialized(void)

Source Code

Returns true if the native dialog addon is initialized, otherwise returns false.

Since: 5.2.6

al_shutdown_native_dialog_addon

void al_shutdown_native_dialog_addon(void)

Source Code

Shut down the native dialog addon.

Since: 5.0.9, 5.1.5

al_create_native_file_dialog

ALLEGRO_FILECHOOSER *al_create_native_file_dialog(
   char const *initial_path,
   char const *title,
   char const *patterns,
   int mode)

Source Code

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 string containing newline separated sets of patterns to match. A pattern is either a shell-style glob pattern (e.g. "*.txt") or a MIME type (e.g. "image/png"). Not all platforms support both (and some don’t even support globs), so a portable solution is to specify a MIME type and simple style globs which Allegro will pick from to match what the platform supports (e.g. do "image/png;*.png"). Multiple patterns are separated using a semicolon. If the platform does not provide support for patterns, this parameter is ignored. Here are some example patterns:
- "*.txt" – defines a single filter, matching *.txt files.
- "*.txt;*.md" – like above, but matching two types of files.
- "Text files (*.txt, *.md) *.txt;*.md" – like above, but with a custom description (separated from the patterns using a space).
- "Text files *.txt\nPNG images image/png;*.png" – defines two filters, with the second filter using a MIME type and extension at the same time.
Note: Windows does not support MIME types. Android supports only MIME types. Instead of file patterns, MacOS supports extensions, so matching based on filename beyond file type does not work. Allegro will parse your file pattern to try to extract the file extension. MacOS also supports MIME types, which behave more predictably. MacOS does not support detailed descriptions or multiple pattern sets, Allegro will strip the detailed descriptions and concatenate all patterns into one list.
mode: 0, or a combination of the following flags:

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 it is 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 it is 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 using al_get_native_file_dialog_count and al_get_native_file_dialog_path. 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.

Examples:

ex_native_filechooser.c

al_show_native_file_dialog

bool al_show_native_file_dialog(ALLEGRO_DISPLAY *display,
   ALLEGRO_FILECHOOSER *dialog)

Source Code

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.

Note: On Android, ALLEGRO_EVENT_DISPLAY_HALT_DRAWING and ALLEGRO_EVENT_DISPLAY_RESUME_DRAWING need to be handled before this function returns. This means that you must call it from a different thread.

Examples:

ex_native_filechooser.c

al_get_native_file_dialog_count

int al_get_native_file_dialog_count(const ALLEGRO_FILECHOOSER *dialog)

Source Code

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

Examples:

ex_native_filechooser.c

al_get_native_file_dialog_path

const char *al_get_native_file_dialog_path(
   const ALLEGRO_FILECHOOSER *dialog, size_t i)

Source Code

Returns one of the selected paths with index i. The index should range from 0 to the return value of al_get_native_file_dialog_count -1.

Note: On Android, this function returns a content:// Universal Resource Identifier instead of a file path due to the constraints of Scoped Storage. Selected files may be accessed using al_android_open_fd.

Examples:

ex_native_filechooser.c

al_destroy_native_file_dialog

void al_destroy_native_file_dialog(ALLEGRO_FILECHOOSER *dialog)

Source Code

Frees up all resources used by the file dialog.

Examples:

ex_native_filechooser.c

al_show_native_message_box

int al_show_native_message_box(ALLEGRO_DISPLAY *display,
   char const *title, char const *heading, char const *text,
   char const *buttons, int flags)

Source Code

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 (|).

Note: The buttons parameter is currently unimplemented on Windows.

The flags available are:

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: Display a cancel button alongside the “OK” button. Ignored if buttons is not NULL.
ALLEGRO_MESSAGEBOX_YES_NO: Display Yes/No buttons instead of the “OK” button. 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 during initialisation of 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.

All of the remaining parameters must not be NULL.

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

Example:

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
);

Examples:

al_open_native_text_log

ALLEGRO_TEXTLOG *al_open_native_text_log(char const *title, int flags)

Source Code

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.

Note: On Android, logs can be viewed using logcat.

Examples:

al_close_native_text_log

void al_close_native_text_log(ALLEGRO_TEXTLOG *textlog)

Source Code

Closes a message log window opened with al_open_native_text_log earlier.

Does nothing if passed NULL.

al_append_native_text_log

void al_append_native_text_log(ALLEGRO_TEXTLOG *textlog,
   char const *format, ...)

Source Code

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.

Examples:

al_get_native_text_log_event_source

ALLEGRO_EVENT_SOURCE *al_get_native_text_log_event_source(
   ALLEGRO_TEXTLOG *textlog)

Source Code

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.

Examples:

al_get_allegro_native_dialog_version

uint32_t al_get_allegro_native_dialog_version(void)

Source Code

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

Menus

Menus are implemented on Windows, X and OS X. Menus on X are implemented with GTK, and have a special requirement: you must set the ALLEGRO_GTK_TOPLEVEL display flag prior to creating the display which will have menus attached.

A menu can be attached to a single display window or popped up as a context menu. If you wish to use the same menu on multiple displays or use a sub-menu as a context menu, you must make a copy via al_clone_menu or al_clone_menu_for_popup.

Top level items in a non-popup menu must have at least one sub-item, or the behavior is undefined.

Each menu item can be given an ID of any 16-bit integer greater than zero. When a user clicks on a menu item, an event will be generated only if it has an ID. This ID should be unique per menu; if you duplicate IDs, then there will be no way for you to determine exactly which item generated the event.

There are many functions that take pos as a parameter used for locating a particular menu item. In those cases, it represents one of two things: an ID or a zero-based index. Any value greater than zero will always be treated as an ID. Anything else (including zero) will be considered an index based on the absolute value. In other words, 0 is the first menu item, -1 is the second menu item, -2 is the third menu item, and so on.

The event type is ALLEGRO_EVENT_MENU_CLICK. It contains three fields:

event.user.data1 = id;
event.user.data2 = (intptr_t) display;
event.user.data3 = (intptr_t) menu;

The display and menu may be NULL if it was not possible to tell exactly which item generated the event.

A basic example:

 #define FILE_EXIT_ID 1

ALLEGRO_MENU *menu = al_create_menu();
ALLEGRO_MENU *file_menu = al_create_menu();
al_append_menu_item(file_menu, "Exit", FILE_EXIT_ID, 0, NULL, NULL);
al_append_menu_item(menu, "File", 0, 0, NULL, file_menu);
al_set_display_menu(display, menu);

al_register_event_source(queue, al_get_default_menu_event_source());
al_wait_for_event(queue, &event);

if (event.type == ALLEGRO_EVENT_MENU_CLICK) {
   if (event.user.data1 == FILE_EXIT_ID) {
      exit_program();
   }
}

Because there is no “DISPLAY_DESTROYED” event, you must call al_set_display_menu(display, NULL) before destroying any display with a menu attached, to avoid leaking resources.

ALLEGRO_MENU

typedef struct ALLEGRO_MENU ALLEGRO_MENU;

Source Code

An opaque data type that represents a menu that contains menu items. Each of the menu items may optionally include a sub-menu.

Examples:

ex_menu.c

ALLEGRO_MENU_INFO

typedef struct ALLEGRO_MENU_INFO {

Source Code

A structure that defines how to create a complete menu system. For standard menu items, the following format is used:

   { caption, id, flags, icon }

For special items, these macros are helpful:

ALLEGRO_START_OF_MENU(caption, id)
ALLEGRO_MENU_SEPARATOR
ALLEGRO_END_OF_MENU

A well-defined menu will begin with ALLEGRO_START_OF_MENU, contain one or more menu items, and end with ALLEGRO_END_OF_MENU. A menu may contain sub-menus. An example:

ALLEGRO_MENU_INFO menu_info[] = {
   ALLEGRO_START_OF_MENU("&File", 1),
      { "&Open", 2, 0, NULL },
      ALLEGRO_START_OF_MENU("Open &Recent...", 3),
         { "Recent 1", 4, 0, NULL },
         { "Recent 2", 5, 0, NULL },
         ALLEGRO_END_OF_MENU,
      ALLEGRO_MENU_SEPARATOR,
      { "E&xit", 6, 0, NULL },
      ALLEGRO_END_OF_MENU,
   ALLEGRO_START_OF_MENU("&Help", 7),
      {"&About", 8, 0, NULL },
      ALLEGRO_END_OF_MENU,
   ALLEGRO_END_OF_MENU
};

ALLEGRO_MENU *menu = al_build_menu(menu_info);

If you prefer, you can build the menu without the structure by using al_create_menu and al_insert_menu_item.

al_create_menu

ALLEGRO_MENU *al_create_menu(void)

Source Code

Creates a menu container that can hold menu items.

Returns NULL on failure.

Since: 5.1.0

al_create_popup_menu

ALLEGRO_MENU *al_create_popup_menu(void)

Source Code

Creates a menu container for popup menus. Only the root (outermost) menu should be created with this function. Sub menus of popups should be created with al_create_menu.

Returns NULL on failure.

Since: 5.1.0

al_build_menu

ALLEGRO_MENU *al_build_menu(ALLEGRO_MENU_INFO *info)

Source Code

Builds a menu based on the specifications of a sequence of ALLEGRO_MENU_INFO elements.

Returns a pointer to the root ALLEGRO_MENU, or NULL on failure. To gain access to the other menus and items, you will need to search for them using al_find_menu_item.

Since: 5.1.0

Examples:

ex_menu.c

al_append_menu_item

int al_append_menu_item(ALLEGRO_MENU *parent, char const *title, uint16_t id,
   int flags, ALLEGRO_BITMAP *icon, ALLEGRO_MENU *submenu)

Source Code

Appends a menu item to the end of the menu. See al_insert_menu_item for more information.

Since: 5.1.0

Examples:

ex_menu.c

al_insert_menu_item

int al_insert_menu_item(ALLEGRO_MENU *parent, int pos, char const *title,
   uint16_t id, int flags, ALLEGRO_BITMAP *icon, ALLEGRO_MENU *submenu)

Source Code

Inserts a menu item at the spot specified. See the introductory text for a detailed explanation of how the pos parameter is interpreted.

The parent menu can be a popup menu or a regular menu. To underline one character in the title, prefix it with an ampersand.

The flags can be any combination of:

ALLEGRO_MENU_ITEM_DISABLED: The item is “grayed out” and cannot be selected.
ALLEGRO_MENU_ITEM_CHECKBOX: The item is a check box. This flag can only be set at the time the menu is created. If a check box is clicked, it will automatically be toggled.
ALLEGRO_MENU_ITEM_CHECKED: The item is checked. If set, ALLEGRO_MENU_ITEM_CHECKBOX will automatically be set as well.

The icon is not yet supported.

The submenu parameter indicates that this item contains a child menu. The child menu must have previously been created with al_create_menu, and not be associated with any other menu.

Returns true on success.

Since: 5.1.0

al_remove_menu_item

bool al_remove_menu_item(ALLEGRO_MENU *menu, int pos)

Source Code

Removes the specified item from the menu and destroys it. If the item contains a sub-menu, it too is destroyed. Any references to it are invalidated. If you want to preserve that sub-menu, you should first make a copy with al_clone_menu.

This is safe to call on a menu that is currently being displayed.

Returns true if an item was removed.

Since: 5.1.0

Examples:

ex_menu.c

al_clone_menu

ALLEGRO_MENU *al_clone_menu(ALLEGRO_MENU *menu)

Source Code

Makes a copy of a menu so that it can be reused on another display. The menu being cloned can be anything: a regular menu, a popup menu, or a sub-menu.

Returns the cloned menu.

Since: 5.1.0

al_clone_menu_for_popup

ALLEGRO_MENU *al_clone_menu_for_popup(ALLEGRO_MENU *menu)

Source Code

Exactly like al_clone_menu, except that the copy is for a popup menu.

Since: 5.1.0

al_destroy_menu

void al_destroy_menu(ALLEGRO_MENU *menu)

Source Code

Destroys an entire menu, including its sub-menus. Any references to it or a sub-menu are no longer valid. It is safe to call this on a menu that is currently being displayed.

Since: 5.1.0

al_get_menu_item_caption

const char *al_get_menu_item_caption(ALLEGRO_MENU *menu, int pos)

Source Code

Returns the caption associated with the menu item. It is valid as long as the caption is not modified.

Returns NULL if the item was not found.

Since: 5.1.0

al_set_menu_item_caption

void al_set_menu_item_caption(ALLEGRO_MENU *menu, int pos, const char *caption)

Source Code

Updates the menu item caption with the new caption. This will invalidate any previous calls to al_get_menu_item_caption.

Since: 5.1.0

al_get_menu_item_flags

int al_get_menu_item_flags(ALLEGRO_MENU *menu, int pos)

Source Code

Returns the currently set flags. See al_insert_menu_item for a description of the available flags.

Returns -1 if the item was not found.

Since: 5.1.0

Examples:

ex_menu.c

al_set_menu_item_flags

void al_set_menu_item_flags(ALLEGRO_MENU *menu, int pos, int flags)

Source Code

Updates the menu item’s flags. See al_insert_menu_item for a description of the available flags.

Since: 5.1.0

Examples:

ex_menu.c

al_toggle_menu_item_flags

int al_toggle_menu_item_flags(ALLEGRO_MENU *menu, int pos, int flags)

Source Code

Toggles the specified menu item’s flags. See al_insert_menu_item for a description of the available flags.

Returns a bitfield of only the specified flags that are set after the toggle. A flag that was not toggled will not be returned, even if it is set. Returns -1 if the id is invalid.

Since: 5.1.0

Unstable API: Redundant with al_get/set_menu_item_flags.

al_get_menu_item_icon

ALLEGRO_BITMAP *al_get_menu_item_icon(ALLEGRO_MENU *menu, int pos)

Source Code

Returns the icon associated with the menu. It is safe to draw to the returned bitmap, but you must call al_set_menu_item_icon in order for the changes to be applied.

Returns NULL if the item was not found or if it has no icon.

Since: 5.1.0

al_set_menu_item_icon

void al_set_menu_item_icon(ALLEGRO_MENU *menu, int pos, ALLEGRO_BITMAP *icon)

Source Code

Sets the icon for the specified menu item. The menu assumes ownership of the ALLEGRO_BITMAP and may invalidate the pointer, so you must clone it if you wish to continue using it.

If a video bitmap is passed, it will automatically be converted to a memory bitmap, so it is preferable to pass a memory bitmap.

Since: 5.1.0

Examples:

ex_menu.c

al_find_menu

ALLEGRO_MENU *al_find_menu(ALLEGRO_MENU *haystack, uint16_t id)

Source Code

Searches in the haystack menu for any submenu with the given id. (Note that this only represents a literal ID, and cannot be used as an index.)

Returns the menu, if found. Otherwise returns NULL.

Since: 5.1.0

al_find_menu_item

bool al_find_menu_item(ALLEGRO_MENU *haystack, uint16_t id, ALLEGRO_MENU **menu,
   int *index)

Source Code

Searches in the haystack menu for an item with the given id. (Note that this only represents a literal ID, and cannot be used as an index.)

If menu and index are not NULL, they will be set as the parent menu containing the item and the zero-based (positive) index of the item. (If the menu item was not found, then their values are undefined.)

Returns true if the menu item was found.

Since: 5.1.0

al_get_default_menu_event_source

ALLEGRO_EVENT_SOURCE *al_get_default_menu_event_source(void)

Source Code

Returns the default event source used for menu clicks. If a menu was not given its own event source via al_enable_menu_event_source, then it will use this default source.

Since: 5.1.0

Examples:

ex_menu.c

al_enable_menu_event_source

ALLEGRO_EVENT_SOURCE *al_enable_menu_event_source(ALLEGRO_MENU *menu)

Source Code

Enables a unique event source for this menu. It and all of its sub-menus will use this event source. (It is safe to call this multiple times on the same menu.)

Returns the event source.

Since: 5.1.0

al_disable_menu_event_source

void al_disable_menu_event_source(ALLEGRO_MENU *menu)

Source Code

Disables a unique event source for the menu, causing it to use the default event source.

Since: 5.1.0

al_get_display_menu

ALLEGRO_MENU *al_get_display_menu(ALLEGRO_DISPLAY *display)

Source Code

Returns the menu associated with the display, or NULL if it does not have a menu.

Since: 5.1.0

al_set_display_menu

bool al_set_display_menu(ALLEGRO_DISPLAY *display, ALLEGRO_MENU *menu)

Source Code

Associates the menu with the display and shows it. If there was a previous menu associated with the display, it will be destroyed. If you don’t want that to happen, you should first remove the menu with al_remove_display_menu.

If the menu is already attached to a display, it will not be attached to the new display. If menu is NULL, the current menu will still be destroyed.

Note: Attaching a menu may cause the window as available to your application to be resized! You should listen for a resize event, check how much space was lost, and resize the window accordingly if you want to maintain your window’s prior size.

Returns true if successful.

Since: 5.1.0

Examples:

ex_menu.c

al_popup_menu

bool al_popup_menu(ALLEGRO_MENU *popup, ALLEGRO_DISPLAY *display)

Source Code

Displays a context menu next to the mouse cursor. The menu must have been created with al_create_popup_menu. It generates events just like a regular display menu does. It is possible that the menu will be canceled without any selection being made.

The display parameter indicates which window the menu is associated with (when you process the menu click event), but does not actually affect where the menu is located on the screen.

Returns true if the context menu was displayed.

Note: On Linux this function will fail if any of the mouse keys are held down. I.e. it will only reliably work if you handle it in ALLEGRO_MOUSE_BUTTON_UP events and even then only if that event corresponds to the final mouse button that was pressed.

Since: 5.1.0

al_remove_display_menu

ALLEGRO_MENU *al_remove_display_menu(ALLEGRO_DISPLAY *display)

Source Code

Detaches the menu associated with the display and returns it. The menu can then be used on a different display.

If you simply want to destroy the active menu, you can call al_set_display_menu with a NULL menu.

Since: 5.1.0