# A - Class Reference

This appendix describes all classes in FLTK and their methods. For a description of the `fl_` functions, see Appendix B.

## Alphabetical List of Classes

Fl
Fl_Adjuster
Fl_Bitmap
Fl_BMP_Image
Fl_Box
Fl_Browser_
Fl_Browser
Fl_Button
Fl_Chart
Fl_Check_Browser
Fl_Check_Button
Fl_Choice
Fl_Clock
Fl_Clock_Output
Fl_Color_Chooser
Fl_Counter
Fl_Dial
Fl_Double_Window
Fl_End
Fl_File_Browser
Fl_File_Chooser
Fl_File_Icon
Fl_File_Input
Fl_Float_Input
Fl_Free
Fl_GIF_Image
Fl_Gl_Window
Fl_Group
Fl_Help_Dialog
Fl_Help_View
Fl_Hold_Browser
Fl_Image
Fl_Input_
Fl_Input
Fl_Input_Choice
Fl_Int_Input
Fl_JPEG_Image
Fl_Light_Button
Fl_Menu_Bar
Fl_Menu_Button
Fl_Menu_
Fl_Menu_Item
Fl_Menu_Window

Fl_Multi_Browser
Fl_Multiline_Input
Fl_Multiline_Output
Fl_Output
Fl_Overlay_Window
Fl_Pack
Fl_Pixmap
Fl_PNG_Image
Fl_PNM_Image
Fl_Positioner
Fl_Preferences
Fl_Progress
Fl_Repeat_Button
Fl_Return_Button
Fl_RGB_Image
Fl_Roller
Fl_Round_Button
Fl_Scrollbar
Fl_Scroll
Fl_Secret_Input
Fl_Select_Browser
Fl_Shared_Image
Fl_Single_Window
Fl_Slider
Fl_Spinner
Fl_Tabs
Fl_Text_Buffer
Fl_Text_Display
Fl_Text_Editor
Fl_Tiled_Image
Fl_Tile
Fl_Timer
Fl_Toggle_Button
Fl_Tooltip
Fl_Valuator
Fl_Value_Input
Fl_Value_Output
Fl_Value_Slider
Fl_Widget
Fl_Window
Fl_Wizard
Fl_XBM_Image
Fl_XPM_Image

## Class Hierarchy

- Fl
- Fl_End
- Fl_File_Icon
- Fl_Help_Dialog
- Fl_Image
  - Fl_Bitmap
    - Fl_XBM_Image
  - Fl_Pixmap
    - Fl_GIF_Image
    - Fl_XPM_Image
  - Fl_RGB_Image
    - Fl_BMP_Image
    - Fl_JPEG_Image
    - Fl_PNG_Image
    - Fl_PNM_Image
  - Fl_Shared_Image
  - Fl_Tiled_Image
- Fl_Menu_Item
- Fl_Preferences
- Fl_Text_Buffer
- Fl_Tooltip
- Fl_Widget
  - Fl_Box
  - Fl_Button
    - Fl_Check_Button
    - Fl_Light_Button
    - Fl_Repeat_Button
    - Fl_Return_Button
    - Fl_Round_Button
    - Fl_Toggle_Button
  - Fl_Chart
  - Fl_Clock_Output
    - Fl_Clock
  - Fl_File_Chooser
  - Fl_Free
  - Fl_Group
    - Fl_Browser_
      - Fl_Browser
        - Fl_File_Browser
        - Fl_Hold_Browser
        - Fl_Multi_Browser
        - Fl_Select_Browser
      - Fl_Check_Browser
    - Fl_Color_Chooser
    - Fl_Help_View
    - Fl_Input_Choice
    - Fl_Pack
    - Fl_Scroll
    - Fl_Spinner
    - Fl_Tabs
    - Fl_Text_Display
      - Fl_Text_Editor
    - Fl_Tile
    - Fl_Window
      - Fl_Double_Window
      - Fl_Gl_Window
      - Fl_Menu_Window
      - Fl_Overlay_Window
      - Fl_Single_Window
    - Fl_Wizard
  - Fl_Input_
    - Fl_Input
      - Fl_File_Input
      - Fl_Float_Input
      - Fl_Int_Input
      - Fl_Multiline_Input
      - Fl_Secret_Input
      - Fl_Output
        - Fl_Multiline_Output
  - Fl_Menu_
    - Fl_Choice
    - Fl_Menu_Bar
    - Fl_Menu_Button
  - Fl_Positioner
  - Fl_Progress
  - Fl_Timer
  - Fl_Valuator
    - Fl_Adjuster
    - Fl_Counter
    - Fl_Dial
    - Fl_Roller
    - Fl_Slider
      - Fl_Scrollbar
      - Fl_Value_Slider
    - Fl_Value_Input
    - Fl_Value_Output

## Alphabetical List of Methods

### A

- activate: Fl_Menu_Item, Fl_Widget
- active: Fl_Menu_Item, Fl_Widget
- active_r: Fl_Widget
- add: Fl_File_Icon, Fl_Browser, Fl_Chart, Fl_Check_Browser, Fl_Group, Fl_Input_Choice, Fl_Menu_
- add_color: Fl_File_Icon
- add_default_key_bindings: Fl_Text_Editor
- add_key_binding: Fl_Text_Editor
- add_modify_callback: Fl_Text_Buffer
- add_resizable: Fl_Group
- add_vertex: Fl_File_Icon
- align: Fl_Scroll, Fl_Widget
- angle1: Fl_Dial
- angle2: Fl_Dial
- angles: Fl_Dial
- append: Fl_Text_Buffer
- appendfile: Fl_Text_Buffer
- argument: Fl_Menu_Item, Fl_Widget
- array: Fl_Group
- autosize: Fl_Chart

### B

- b: Fl_Color_Chooser
- bbox: Fl_Browser_
- begin: Fl_Group
- border: Fl_Window
- bottomline: Fl_Browser
- bound_key_function: Fl_Text_Editor
- bounds: Fl_Valuator, Fl_Chart
- box: Fl_Widget
- buffer: Fl_Text_Display

### C

- call_modify_callbacks: Fl_Text_Buffer
- callback: Fl_Menu_Item, Fl_Widget
- can_do: Fl_Gl_Window
- can_do_overlay: Fl_Gl_Window
- changed: Fl_Valuator, Fl_Choice, Fl_Widget
- character: Fl_Text_Buffer
- character_width: Fl_Text_Buffer
- check_all: Fl_Check_Browser
- check_none: Fl_Check_Browser
- checkbox: Fl_Menu_Item
- checked: Fl_Check_Browser
- child: Fl_Group
- children: Fl_Group
- clamp: Fl_Valuator
- clear: Fl_File_Icon, Fl_Group, Fl_Browser, Fl_Button, Fl_Chart, Fl_Check_Browser, Fl_Input_Choice, Fl_Menu_, Fl_Menu_Item
- clear_border: Fl_Window
- clear_changed: Fl_Valuator, Fl_Choice, Fl_Widget
- clear_output: Fl_Widget
- clear_overlay: Fl_Menu_Window
- clear_rectangular: Fl_Text_Buffer
- clear_visible: Fl_Widget
- clear_visible_focus: Fl_Widget
- color: Fl_File_Chooser, Fl_Tooltip, Fl_Widget
- color_average: Fl_Image
- column_char: Fl_Browser
- column_widths: Fl_Browser
- contains: Fl_Widget
- context: Fl_Gl_Window
- context_valid: Fl_Gl_Window
- copy: Fl_Text_Buffer, Fl_Image, Fl_Input_, Fl_Menu_
- copy_cuts: Fl_Input_
- copy_label: Fl_Widget
- count: Fl_File_Chooser, Fl_Image
- count_displayed_characters: Fl_Text_Buffer
- count_lines: Fl_Text_Buffer
- current: Fl_Group, Fl_Window
- cursor: Fl_Window
- cursor_color: Fl_Text_Display, Fl_Value_Input, Fl_Input
- cursor_style: Fl_Text_Display
- cut: Fl_Input_

### D

- d: Fl_Image
- damage: Fl_Widget
- data: Fl_Image, Fl_Browser
- deactivate: Fl_Menu_Item, Fl_Widget
- default_callback: Fl_Widget
- default_key_function: Fl_Text_Editor
- deimage: Fl_Widget
- delay: Fl_Tooltip
- deleteEntry: Fl_Preferences
- deleteGroup: Fl_Preferences
- deleting: Fl_Browser_
- desaturate: Fl_Image
- deselect: Fl_Browser_, Fl_Hold_Browser, Fl_Multi_Browser, Fl_Select_Browser
- direction: Fl_Timer
- directory: Fl_File_Chooser, Fl_Help_View
- disable: Fl_Tooltip
- display: Fl_Browser_
- displayed: Fl_Browser_
- do_callback: Fl_Menu_Item, Fl_Widget
- down_box: Fl_File_Input, Fl_Button, Fl_Choice, Fl_Menu_
- draw: Fl_File_Icon, Fl_Browser_, Fl_Image, Fl_Gl_Window
- draw_empty: Fl_Image
- draw_overlay: Fl_Gl_Window, Fl_Overlay_Window
- drawtext: Fl_Input_

### E

- enable: Fl_Tooltip
- enabled: Fl_Tooltip
- end: Fl_Group
- enter: Fl_Tooltip
- enter_area: Fl_Tooltip
- entries: Fl_Preferences
- entry: Fl_Preferences
- entryExists: Fl_Preferences
- exit: Fl_Tooltip
- expand_character: Fl_Text_Buffer

### F

- filename: Fl_Help_View
- filetype: Fl_File_Browser
- filter: Fl_File_Browser, Fl_File_Chooser
- filter_value: Fl_File_Chooser
- find: Fl_File_Icon, Fl_Shared_Image, Fl_Group
- find_item: Fl_Browser_, Fl_Menu_
- findchar_backward: Fl_Text_Buffer
- findchar_forward: Fl_Text_Buffer
- findchars_backward: Fl_Text_Buffer
- findchars_forward: Fl_Text_Buffer
- first: Fl_File_Icon
- font: Fl_Tooltip
- format: Fl_Valuator, Fl_Spinner
- format_char: Fl_Browser
- free_position: Fl_Window
- full_height: Fl_Browser_
- full_width: Fl_Browser_
- fullscreen: Fl_Window
- fullscreen_off: Fl_Window

### G

- g: Fl_Color_Chooser
- get: Fl_Shared_Image, Fl_Preferences
- getUserdataPath: Fl_Preferences
- global: Fl_Menu_
- group: Fl_Preferences
- groupExists: Fl_Preferences
- groups: Fl_Preferences

### H

- h: Fl_Image, Fl_Widget
- handle: Fl_Browser_, Fl_Widget
- handletext: Fl_Input_
- has_scrollbar: Fl_Browser_
- hide: Fl_File_Chooser, Fl_Help_Dialog, Fl_Browser, Fl_Gl_Window, Fl_Menu_Item, Fl_Widget, Fl_Window
- hide_cursor: Fl_Text_Display
- highlight: Fl_Text_Buffer
- highlight_data: Fl_Text_Display
- highlight_position: Fl_Text_Buffer
- highlight_rectangular: Fl_Text_Buffer
- highlight_selection: Fl_Text_Buffer
- highlight_text: Fl_Text_Buffer
- hotspot: Fl_Window
- hour: Fl_Clock, Fl_Clock_Output
- hoverdelay: Fl_Tooltip
- hposition: Fl_Browser_
- hsv2rgb: Fl_Color_Chooser
- hsv: Fl_Color_Chooser
- hue: Fl_Color_Chooser

### I

- iconize: Fl_Window
- iconlabel: Fl_Window
- iconsize: Fl_File_Browser, Fl_File_Chooser
- image: Fl_Tiled_Image, Fl_Widget
- images: Fl_Shared_Image
- in_selection: Fl_Text_Display
- inactive: Fl_Image
- incr_height: Fl_Browser_
- increment: Fl_Valuator
- index: Fl_Input, Fl_Output
- init_sizes: Fl_Group
- input: Fl_Input_Choice
- input_type: Fl_Input_
- insert: Fl_Text_Buffer, Fl_Text_Display, Fl_Input_, Fl_Browser, Fl_Chart, Fl_Group
- insert_column: Fl_Text_Buffer
- insert_mode: Fl_Text_Editor
- insert_position: Fl_Text_Display
- insertfile: Fl_Text_Buffer
- inserting: Fl_Browser_
- inside: Fl_Widget
- invalidate: Fl_Gl_Window
- item_draw: Fl_Browser_
- item_first: Fl_Browser_
- item_height: Fl_Browser_
- item_next: Fl_Browser_
- item_pathname: Fl_Menu_
- item_prev: Fl_Browser_
- item_quick_height: Fl_Browser_
- item_select: Fl_Browser_
- item_selected: Fl_Browser_
- item_width: Fl_Browser_

### K

- kf_backspace: Fl_Text_Editor
- kf_c_s_move: Fl_Text_Editor
- kf_copy: Fl_Text_Editor
- kf_ctrl_move: Fl_Text_Editor
- kf_cut: Fl_Text_Editor
- kf_default: Fl_Text_Editor
- kf_delete: Fl_Text_Editor
- kf_down: Fl_Text_Editor
- kf_end: Fl_Text_Editor
- kf_enter: Fl_Text_Editor
- kf_home: Fl_Text_Editor
- kf_ignore: Fl_Text_Editor
- kf_insert: Fl_Text_Editor
- kf_left: Fl_Text_Editor
- kf_move: Fl_Text_Editor
- kf_page_down: Fl_Text_Editor
- kf_page_up: Fl_Text_Editor
- kf_paste: Fl_Text_Editor
- kf_right: Fl_Text_Editor
- kf_select_all: Fl_Text_Editor
- kf_shift_move: Fl_Text_Editor
- kf_up: Fl_Text_Editor

### L

- label: Fl_File_Chooser, Fl_File_Icon, Fl_Image, Fl_Menu_Item, Fl_Widget, Fl_Window
- labelcolor: Fl_Menu_Item, Fl_Widget
- labelfont: Fl_Menu_Item, Fl_Widget
- labelsize: Fl_Menu_Item, Fl_Widget
- labeltype: Fl_File_Icon, Fl_Menu_Item, Fl_Widget
- ld: Fl_Image
- leftedge: Fl_Browser_
- length: Fl_Text_Buffer
- line_end: Fl_Text_Buffer
- line_start: Fl_Text_Buffer
- line_text: Fl_Text_Buffer
- lineboundary: Fl_Input_
- linesize: Fl_Scrollbar
- link: Fl_Help_View
- load: Fl_File_Browser, Fl_File_Icon, Fl_Help_Dialog, Fl_Help_View, Fl_Browser
- load_fti: Fl_File_Icon
- load_system_icons: Fl_File_Icon
- load_xpm: Fl_File_Icon
- loadfile: Fl_Text_Buffer
- lstep: Fl_Counter

### M

- make_current: Fl_Gl_Window, Fl_Window
- make_overlay_current: Fl_Gl_Window
- mark: Fl_Input_
- maximum: Fl_Progress, Fl_Valuator, Fl_Spinner
- maximum_size: Fl_Input_
- maxsize: Fl_Chart
- maybe_do_callback: Fl_Input_
- menu: Fl_Input_Choice, Fl_Menu_
- menubutton: Fl_Input_Choice
- middleline: Fl_Browser
- minimum: Fl_Progress, Fl_Valuator, Fl_Spinner
- minute: Fl_Clock, Fl_Clock_Output
- modal: Fl_Window
- mode: Fl_Gl_Window, Fl_Menu_
- move: Fl_Browser
- move_down: Fl_Text_Display
- move_left: Fl_Text_Display
- move_right: Fl_Text_Display
- move_up: Fl_Text_Display
- mvalue: Fl_Menu_

### N

- name: Fl_Shared_Image
- nchecked: Fl_Check_Browser
- new_list: Fl_Browser_
- next: Fl_Wizard, Fl_Menu_Item
- next_word: Fl_Text_Display
- nitems: Fl_Check_Browser
- non_modal: Fl_Window
- null_substitution_character: Fl_Text_Buffer
- num_images: Fl_Shared_Image

### O

- ok_label: Fl_File_Chooser
- ortho: Fl_Gl_Window
- output: Fl_Widget
- outputfile: Fl_Text_Buffer
- overlay_rectangular: Fl_Text_Buffer
- overstrike: Fl_Text_Display

### P

- parent: Fl_Widget
- pattern: Fl_File_Icon
- popup: Fl_Menu_Button, Fl_Menu_Item
- position: Fl_Browser_, Fl_Input_, Fl_Browser, Fl_Scroll, Fl_Tile, Fl_Widget
- position_style: Fl_Text_Display
- precision: Fl_Valuator
- prev: Fl_Wizard
- preview: Fl_File_Chooser
- previous_word: Fl_Text_Display
- primary_selection: Fl_Text_Buffer
- pulldown: Fl_Menu_Item

### R

- r: Fl_Color_Chooser
- radio: Fl_Menu_Item
- range: Fl_Valuator, Fl_Spinner
- readonly: Fl_Input_
- redisplay_range: Fl_Text_Display
- redraw: Fl_Widget
- redraw_label: Fl_Widget
- redraw_line: Fl_Browser_, Fl_Browser_
- redraw_overlay: Fl_Gl_Window, Fl_Overlay_Window
- refcount: Fl_Shared_Image
- release: Fl_Shared_Image
- reload: Fl_Shared_Image
- remove: Fl_Text_Buffer, Fl_Browser, Fl_Group, Fl_Menu_
- remove_all_key_bindings: Fl_Text_Editor
- remove_key_binding: Fl_Text_Editor
- remove_modify_callback: Fl_Text_Buffer
- remove_rectangular: Fl_Text_Buffer
- remove_secondary_selection: Fl_Text_Buffer
- remove_selection: Fl_Text_Buffer
- replace: Fl_Text_Buffer, Fl_Input_, Fl_Chart, Fl_Menu_
- replace_rectangular: Fl_Text_Buffer
- replace_secondary_selection: Fl_Text_Buffer
- replace_selection: Fl_Text_Buffer
- replacing: Fl_Browser_
- rescan: Fl_File_Chooser
- resizable: Fl_Group
- resize: Fl_Browser_, Fl_Widget, Fl_Window
- resizeable: Fl_Tile
- rewind_lines: Fl_Text_Buffer
- rgb2hsv: Fl_Color_Chooser
- rgb: Fl_Color_Chooser
- round: Fl_Valuator

### S

- saturation: Fl_Color_Chooser
- savefile: Fl_Text_Buffer
- scroll: Fl_Text_Display
- scrollbar_align: Fl_Text_Display
- scrollbar_left: Fl_Browser_
- scrollbar_right: Fl_Browser_
- scrollbar_size: Fl
- scrollbar_width: Fl_Browser_, Fl_Text_Display
- scrollvalue: Fl_Slider
- search_backward: Fl_Text_Buffer
- search_forward: Fl_Text_Buffer
- second: Fl_Clock, Fl_Clock_Output
- secondary_select: Fl_Text_Buffer
- secondary_select_rectangular: Fl_Text_Buffer
- secondary_selection: Fl_Text_Buffer
- secondary_selection_position: Fl_Text_Buffer
- secondary_selection_text: Fl_Text_Buffer
- secondary_unselect: Fl_Text_Buffer
- select: Fl_Text_Buffer, Fl_Browser_, Fl_Hold_Browser, Fl_Multi_Browser, Fl_Select_Browser
- select_only: Fl_Browser_
- select_rectangular: Fl_Text_Buffer
- selected: Fl_Text_Buffer
- selection: Fl_Browser_
- selection_color: Fl_Widget
- selection_position: Fl_Text_Buffer
- selection_text: Fl_Text_Buffer
- set: Fl_Button, Fl_Menu_Item, Fl_Preferences
- set_changed: Fl_Valuator, Fl_Choice, Fl_Widget, Fl_Check_Browser
- set_modal: Fl_Window
- set_non_modal: Fl_Window
- set_output: Fl_Widget
- set_overlay: Fl_Menu_Window
- set_visible: Fl_Widget
- set_visible_focus: Fl_Widget
- setonly: Fl_Button, Fl_Menu_Item
- shortcut: Fl_Button, Fl_Menu_, Fl_Menu_Item
- show: Fl_File_Chooser, Fl_Help_Dialog, Fl_Browser, Fl_Menu_Item, Fl_Widget, Fl_Window
- show_cursor: Fl_Text_Display
- show_insert_position: Fl_Text_Display
- shown: Fl_Window
- size: Fl_File_Icon, Fl_Help_View, Fl_Tooltip, Fl_Browser, Fl_Chart, Fl_Input, Fl_Menu_, Fl_Menu_Item, Fl_Output, Fl_Widget, Fl_Preferences
- size_range: Fl_Window
- skip_displayed_characters: Fl_Text_Buffer
- skip_lines: Fl_Text_Buffer
- slider: Fl_Slider
- slider_size: Fl_Slider
- soft: Fl_Value_Input, Fl_Adjuster, Fl_Value_Output
- spacing: Fl_Pack
- static_value: Fl_Input
- step: Fl_Valuator, Fl_Spinner
- submenu: Fl_Menu_Item
- substitute_null_characters: Fl_Text_Buffer
- suspended: Fl_Timer
- swap: Fl_Browser
- swap_buffers: Fl_Gl_Window

### T

- tab_distance: Fl_Text_Buffer
- take_focus: Fl_Widget
- takesevents: Fl_Widget
- test_shortcut: Fl_Menu_, Fl_Menu_Item
- text: Fl_Text_Buffer, Fl_Browser, Fl_Check_Browser, Fl_Menu_
- text_in_rectangle: Fl_Text_Buffer
- text_range: Fl_Text_Buffer
- textcolor: Fl_File_Chooser, Fl_Help_View, Fl_Text_Display, Fl_Tooltip, Fl_Browser_, Fl_Value_Input, Fl_Input, Fl_Menu_, Fl_Output, Fl_Value_Output, Fl_Value_Slider, Fl_Spinner
- textfont: Fl_File_Chooser, Fl_Help_View, Fl_Text_Display, Fl_Browser_, Fl_Value_Input, Fl_Input, Fl_Menu_, Fl_Output, Fl_Value_Output, Fl_Value_Slider, Fl_Spinner
- textsize: Fl_File_Chooser, Fl_Help_View, Fl_Text_Display, Fl_Browser_, Fl_Value_Input, Fl_Input, Fl_Menu_, Fl_Output, Fl_Value_Output, Fl_Value_Slider, Fl_Spinner
- title: Fl_Help_View
- tooltip: Fl_Widget
- top: Fl_Browser_
- topline: Fl_Help_Dialog, Fl_Help_View, Fl_Browser
- type: Fl_File_Chooser, Fl_File_Icon, Fl_Button, Fl_Chart, Fl_Counter, Fl_Dial, Fl_Menu_Button, Fl_Scroll, Fl_Slider, Fl_Widget, Fl_Spinner

### U

- uncache: Fl_Image
- undo: Fl_Input_
- unhighlight: Fl_Text_Buffer
- unselect: Fl_Text_Buffer
- unsubstitute_null_characters: Fl_Text_Buffer
- up_down_position: Fl_Input_
- user_data: Fl_Menu_Item, Fl_Widget

### V

- valid: Fl_Gl_Window
- value: Fl_File_Chooser, Fl_File_Icon, Fl_Help_Dialog, Fl_Help_View, Fl_Wizard, Fl_Progress, Fl_Tabs, Fl_Valuator, Fl_Button, Fl_Check_Browser, Fl_Choice, Fl_Clock, Fl_Clock_Output, Fl_Color_Chooser, Fl_Hold_Browser, Fl_Input, Fl_Input_Choice, Fl_Menu_, Fl_Menu_Item, Fl_Multi_Browser, Fl_Output, Fl_Positioner, Fl_Scrollbar, Fl_Select_Browser, Fl_Timer, Fl_Spinner
- visible: Fl_File_Chooser, Fl_Help_Dialog, Fl_Browser, Fl_Menu_Item, Fl_Widget
- visible_focus: Fl_Widget
- visible_r: Fl_Widget

### W

- w: Fl_Image, Fl_Widget
- when: Fl_Button, Fl_Input, Fl_Widget
- window: Fl_Widget
- word_end: Fl_Text_Buffer, Fl_Text_Display
- word_start: Fl_Text_Buffer, Fl_Text_Display
- wrap: Fl_Input_
- wrap_mode: Fl_Text_Display

### X

- x: Fl_Widget
- xbounds: Fl_Positioner
- xclass: Fl_Window
- xposition: Fl_Scroll
- xstep: Fl_Positioner
- xvalue: Fl_Positioner

### y

- y: Fl_Widget
- ybounds: Fl_Positioner
- yposition: Fl_Scroll
- ystep: Fl_Positioner
- yvalue: Fl_Positioner