/*
 * tkScrollbar.h --
 *
 *	Declarations of types and functions used to implement
 *	the scrollbar widget.
 *
 * Copyright (c) 1996 by Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * SCCS: @(#) tkScrollbar.h 1.8 96/11/05 11:34:58
 */

#ifndef _TKSCROLLBAR
#define _TKSCROLLBAR

#ifndef _TKINT
#include "tkInt.h"
#endif
#include "tkVMacro.h"

/*
 * A data structure of the following type is kept for each scrollbar
 * widget.
 */

typedef struct TkScrollbar {
    Tk_Window tkwin;		/* Window that embodies the scrollbar.  NULL
				 * means that the window has been destroyed
				 * but the data structures haven't yet been
				 * cleaned up.*/
    Display *display;		/* Display containing widget.  Used, among
				 * other things, so that resources can be
				 * freed even after tkwin has gone away. */
    Tcl_Interp *interp;		/* Interpreter associated with scrollbar. */
    Tcl_Command widgetCmd;	/* Token for scrollbar's widget command. */
    Tk_Uid orientUid;		/* Orientation for window ("vertical" or
				 * "horizontal"). */
    int vertical;		/* Non-zero means vertical orientation
				 * requested, zero means horizontal. */
    int width;			/* Desired narrow dimension of scrollbar,
				 * in pixels. */
    LangCallback *command;	/* Command prefix to use when invoking
				 * scrolling commands.  NULL means don't
				 * invoke commands.  Malloc'ed. */
#if 0
    int commandSize;		/* Number of non-NULL bytes in command. */
#endif
    int repeatDelay;		/* How long to wait before auto-repeating
				 * on scrolling actions (in ms). */
    int repeatInterval;		/* Interval between autorepeats (in ms). */
    int jump;			/* Value of -jump option. */

    /*
     * Information used when displaying widget:
     */

    int borderWidth;		/* Width of 3-D borders. */
    Tk_3DBorder bgBorder;	/* Used for drawing background (all flat
				 * surfaces except for trough). */
    Tk_3DBorder activeBorder;	/* For drawing backgrounds when active (i.e.
				 * when mouse is positioned over element). */
    XColor *troughColorPtr;	/* Color for drawing trough. */
    int relief;			/* Indicates whether window as a whole is
				 * raised, sunken, or flat. */
    int highlightWidth;		/* Width in pixels of highlight to draw
				 * around widget when it has the focus.
				 * <= 0 means don't draw a highlight. */
    XColor *highlightBgColorPtr;
				/* Color for drawing traversal highlight
				 * area when highlight is off. */
    XColor *highlightColorPtr;	/* Color for drawing traversal highlight. */
    int inset;			/* Total width of all borders, including
				 * traversal highlight and 3-D border.
				 * Indicates how much interior stuff must
				 * be offset from outside edges to leave
				 * room for borders. */
    int elementBorderWidth;	/* Width of border to draw around elements
				 * inside scrollbar (arrows and slider).
				 * -1 means use borderWidth. */
    int arrowLength;		/* Length of arrows along long dimension of
				 * scrollbar, including space for a small gap
				 * between the arrow and the slider.
				 * Recomputed on window size changes. */
    int sliderFirst;		/* Pixel coordinate of top or left edge
				 * of slider area, including border. */
    int sliderLast;		/* Coordinate of pixel just after bottom
				 * or right edge of slider area, including
				 * border. */
    int activeField;		/* Names field to be displayed in active
				 * colors, such as TOP_ARROW, or 0 for
				 * no field. */
    int activeRelief;		/* Value of -activeRelief option: relief
				 * to use for active element. */

    /*
     * Information describing the application related to the scrollbar.
     * This information is provided by the application by invoking the
     * "set" widget command.  This information can now be provided in
     * two ways:  the "old" form (totalUnits, windowUnits, firstUnit,
     * and lastUnit), or the "new" form (firstFraction and lastFraction).
     * FirstFraction and lastFraction will always be valid, but
     * the old-style information is only valid if the NEW_STYLE_COMMANDS
     * flag is 0.
     */

    int totalUnits;		/* Total dimension of application, in
				 * units.  Valid only if the NEW_STYLE_COMMANDS
				 * flag isn't set. */
    int windowUnits;		/* Maximum number of units that can be
				 * displayed in the window at once.  Valid
				 * only if the NEW_STYLE_COMMANDS flag isn't
				 * set. */
    int firstUnit;		/* Number of last unit visible in
				 * application's window.  Valid only if the
				 * NEW_STYLE_COMMANDS flag isn't set. */
    int lastUnit;		/* Index of last unit visible in window.
				 * Valid only if the NEW_STYLE_COMMANDS
				 * flag isn't set. */
    double firstFraction;	/* Position of first visible thing in window,
				 * specified as a fraction between 0 and
				 * 1.0. */
    double lastFraction;	/* Position of last visible thing in window,
				 * specified as a fraction between 0 and
				 * 1.0. */

    /*
     * Miscellaneous information:
     */

    Tk_Cursor cursor;		/* Current cursor for window, or None. */
    char *takeFocus;		/* Value of -takefocus option;  not used in
				 * the C code, but used by keyboard traversal
				 * scripts.  Malloc'ed, but may be NULL. */
    int flags;			/* Various flags;  see below for
				 * definitions. */
} TkScrollbar;

/*
 * Legal values for "activeField" field of Scrollbar structures.  These
 * are also the return values from the ScrollbarPosition procedure.
 */

#define OUTSIDE		0
#define TOP_ARROW	1
#define TOP_GAP		2
#define SLIDER		3
#define BOTTOM_GAP	4
#define BOTTOM_ARROW	5

/*
 * Flag bits for scrollbars:
 * 
 * REDRAW_PENDING:		Non-zero means a DoWhenIdle handler
 *				has already been queued to redraw
 *				this window.
 * NEW_STYLE_COMMANDS:		Non-zero means the new style of commands
 *				should be used to communicate with the
 *				widget:  ".t yview scroll 2 lines", instead
 *				of ".t yview 40", for example.
 * GOT_FOCUS:			Non-zero means this window has the input
 *				focus.
 */

#define REDRAW_PENDING		1
#define NEW_STYLE_COMMANDS	2
#define GOT_FOCUS		4

/*
 * Declaration of scrollbar class procedures structure.
 */

extern TkClassProcs tkpScrollbarProcs;

/*
 * Declaration of scrollbar configuration options.
 */

extern Tk_ConfigSpec tkpScrollbarConfigSpecs[];

/*
 * Declaration of procedures used in the implementation of the scrollbar
 * widget. 
 */

EXTERN void		TkScrollbarEventProc _ANSI_ARGS_((
			    ClientData clientData, XEvent *eventPtr));
EXTERN void		TkScrollbarEventuallyRedraw _ANSI_ARGS_((
			    TkScrollbar *scrollPtr));
EXTERN void		TkpComputeScrollbarGeometry _ANSI_ARGS_((
			    TkScrollbar *scrollPtr));
EXTERN TkScrollbar *	TkpCreateScrollbar _ANSI_ARGS_((Tk_Window tkwin));
EXTERN void 		TkpDestroyScrollbar _ANSI_ARGS_((
    			    TkScrollbar *scrollPtr));
EXTERN void		TkpDisplayScrollbar _ANSI_ARGS_((
			    ClientData clientData));
EXTERN void		TkpConfigureScrollbar _ANSI_ARGS_((
			    TkScrollbar *scrollPtr));
EXTERN int		TkpScrollbarPosition _ANSI_ARGS_((
			    TkScrollbar *scrollPtr, int x, int y));

#endif /* _TKSCROLLBAR */
