with agar.core.tail_queue;
with agar.gui.text;
with agar.gui.widget.box;

package agar.gui.widget.notebook is

  use type c.unsigned;

  type tab_t;
  type tab_access_t is access all tab_t;
  pragma convention (c, tab_access_t);

  package tab_tail_queue is new agar.core.tail_queue
    (entry_type => tab_access_t);

  type tab_alignment_t is (
    NOTEBOOK_TABS_TOP,
    NOTEBOOK_TABS_BOTTOM,
    NOTEBOOK_TABS_LEFT,
    NOTEBOOK_TABS_RIGHT
  );
  for tab_alignment_t use (
    NOTEBOOK_TABS_TOP    => 0,
    NOTEBOOK_TABS_BOTTOM => 1,
    NOTEBOOK_TABS_LEFT   => 2,
    NOTEBOOK_TABS_RIGHT  => 3
  );
  for tab_alignment_t'size use c.unsigned'size;
  pragma convention (c, tab_alignment_t);

  label_max : constant := 64;

  type text_t is array (1 .. label_max) of aliased c.char;
  pragma convention (c, text_t);

  type tab_t is record
    box        : agar.gui.widget.box.box_t;
    label      : c.int;
    label_text : text_t;
    tabs       : tab_tail_queue.entry_t;
  end record;
  pragma convention (c, tab_t);

  type flags_t is new c.unsigned;
  NOTEBOOK_HFILL     : constant flags_t := 16#01#;
  NOTEBOOK_VFILL     : constant flags_t := 16#02#;
  NOTEBOOK_HIDE_TABS : constant flags_t := 16#04#;
  NOTEBOOK_EXPAND    : constant flags_t := NOTEBOOK_HFILL or NOTEBOOK_VFILL;

  type notebook_t is record
    widget              : aliased widget_t;
    tab_align           : tab_alignment_t;
    flags               : flags_t;
    bar_w               : c.int;
    bar_h               : c.int;
    cont_w              : c.int;
    cont_h              : c.int;
    spacing             : c.int;
    padding             : c.int;
    tab_font            : agar.gui.text.font_access_t;
    label_partial       : c.int;
    label_partial_width : c.int;
    sel_tab             : tab_access_t;
    tabs                : tab_tail_queue.head_t;
    r                   : agar.gui.rect.rect_t;
  end record;
  type notebook_access_t is access all notebook_t;
  pragma convention (c, notebook_t);
  pragma convention (c, notebook_access_t);

  -- API

  function allocate
    (parent : widget_access_t;
     flags  : flags_t) return notebook_access_t;
  pragma import (c, allocate, "AG_NotebookNew");

  procedure set_padding
    (notebook : notebook_access_t;
     padding  : natural);
  pragma inline (set_padding);

  procedure set_spacing
    (notebook : notebook_access_t;
     spacing  : natural);
  pragma inline (set_spacing);

  procedure set_tab_alignment
    (notebook  : notebook_access_t;
     alignment : tab_alignment_t);
  pragma import (c, set_tab_alignment, "AG_NotebookSetTabAlignment");

  procedure set_tab_font
    (notebook  : notebook_access_t;
     font      : agar.gui.text.font_access_t);
  pragma import (c, set_tab_font, "AG_NotebookSetTabFont");

  procedure set_tab_visibility
    (notebook : notebook_access_t;
     flag     : boolean := false);
  pragma inline (set_tab_visibility);

  -- tabs

  procedure add_tab
    (notebook : notebook_access_t;
     name     : string;
     box_type : agar.gui.widget.box.type_t);
  pragma inline (add_tab);

  procedure delete_tab
    (notebook : notebook_access_t;
     tab      : tab_access_t);
  pragma import (c, delete_tab, "AG_NotebookDelTab");

  procedure select_tab
    (notebook : notebook_access_t;
     tab      : tab_access_t);
  pragma import (c, select_tab, "AG_NotebookSelectTab");

  function widget (notebook : notebook_access_t) return widget_access_t;
  pragma inline (widget);

end agar.gui.widget.notebook;