/*
 * tkScale.h --
 *
 *	Declarations of types and functions used to implement
 *	the scale 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: @(#) tkScale.h 1.5 96/07/08 12:56:56
 */

#ifndef _TKSCALE
#define _TKSCALE

#ifndef _TK
#include "tk.h"
#endif
#include "tkVMacro.h"

/*
 * A data structure of the following type is kept for each scale
 * widget managed by this file:
 */

typedef struct TkScale {
    Tk_Window tkwin;		/* Window that embodies the scale.  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 scale. */
    Tcl_Command widgetCmd;	/* Token for scale's widget command. */
    Tk_Uid orientUid;		/* Orientation for window ("vertical" or
				 * "horizontal"). */
    int vertical;		/* Non-zero means vertical orientation,
				 * zero means horizontal. */
    int width;			/* Desired narrow dimension of scale,
				 * in pixels. */
    int length;			/* Desired long dimension of scale,
				 * in pixels. */
    double value;		/* Current value of scale. */
    Var varName;		/* Name of variable (malloc'ed) or NULL.
				 * If non-NULL, scale's value tracks
				 * the contents of this variable and
				 * vice versa. */
    double fromValue;		/* Value corresponding to left or top of
				 * scale. */
    double toValue;		/* Value corresponding to right or bottom
				 * of scale. */
    double tickInterval;	/* Distance between tick marks;  0 means
				 * don't display any tick marks. */
    double resolution;		/* If > 0, all values are rounded to an
				 * even multiple of this value. */
    int digits;			/* Number of significant digits to print
				 * in values.  0 means we get to choose the
				 * number based on resolution and/or the
				 * range of the scale. */
    char format[10];		/* Sprintf conversion specifier computed from
				 * digits and other information. */
    double bigIncrement;	/* Amount to use for large increments to
				 * scale value.  (0 means we pick a value). */
    LangCallback *command;	/* Command prefix to use when invoking Tcl
				 * commands because the scale value changed.
				 * NULL means don't invoke commands.
				 * Malloc'ed. */
    int repeatDelay;		/* How long to wait before auto-repeating
				 * on scrolling actions (in ms). */
    int repeatInterval;		/* Interval between autorepeats (in ms). */
    char *label;		/* Label to display above or to right of
				 * scale;  NULL means don't display a
				 * label.  Malloc'ed. */
    int labelLength;		/* Number of non-NULL chars. in label. */
    Tk_Uid state;		/* Normal or disabled.  Value cannot be
				 * changed when scale is disabled. */

    /*
     * Information used when displaying widget:
     */

    int borderWidth;		/* Width of 3-D border around window. */
    Tk_3DBorder bgBorder;	/* Used for drawing slider and other
				 * background areas. */
    Tk_3DBorder activeBorder;	/* For drawing the slider when active. */
    int sliderRelief;		/* Is slider to be drawn raised, sunken, etc. */
    XColor *troughColorPtr;	/* Color for drawing trough. */
    GC troughGC;		/* For drawing trough. */
    GC copyGC;			/* Used for copying from pixmap onto screen. */
    Tk_Font tkfont;		/* Information about text font, or NULL. */
    XColor *textColorPtr;	/* Color for drawing text. */
    GC textGC;			/* GC for drawing text in normal mode. */
    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 sliderLength;		/* Length of slider, measured in pixels along
				 * long dimension of scale. */
    int showValue;		/* Non-zero means to display the scale value
				 * below or to the left of the slider;  zero
				 * means don't display the value. */

    /*
     * Layout information for horizontal scales, assuming that window
     * gets the size it requested:
     */

    int horizLabelY;		/* Y-coord at which to draw label. */
    int horizValueY;		/* Y-coord at which to draw value text. */
    int horizTroughY;		/* Y-coord of top of slider trough. */
    int horizTickY;		/* Y-coord at which to draw tick text. */
    /*
     * Layout information for vertical scales, assuming that window
     * gets the size it requested:
     */

    int vertTickRightX;		/* X-location of right side of tick-marks. */
    int vertValueRightX;	/* X-location of right side of value string. */
    int vertTroughX;		/* X-location of scale's slider trough. */
    int vertLabelX;		/* X-location of origin of label. */

    /*
     * 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. */
} TkScale;

/*
 * Flag bits for scales:
 *
 * REDRAW_SLIDER -		1 means slider (and numerical readout) need
 *				to be redrawn.
 * REDRAW_OTHER -		1 means other stuff besides slider and value
 *				need to be redrawn.
 * REDRAW_ALL -			1 means the entire widget needs to be redrawn.
 * ACTIVE -			1 means the widget is active (the mouse is
 *				in its window).
 * INVOKE_COMMAND -		1 means the scale's command needs to be
 *				invoked during the next redisplay (the
 *				value of the scale has changed since the
 *				last time the command was invoked).
 * SETTING_VAR -		1 means that the associated variable is
 *				being set by us, so there's no need for
 *				ScaleVarProc to do anything.
 * NEVER_SET -			1 means that the scale's value has never
 *				been set before (so must invoke -command and
 *				set associated variable even if the value
 *				doesn't appear to have changed).
 * GOT_FOCUS -			1 means that the focus is currently in
 *				this widget.
 */

#define REDRAW_SLIDER		1
#define REDRAW_OTHER		2
#define REDRAW_ALL		3
#define ACTIVE			4
#define INVOKE_COMMAND		0x10
#define SETTING_VAR		0x20
#define NEVER_SET		0x40
#define GOT_FOCUS		0x80

/*
 * Symbolic values for the active parts of a slider.  These are
 * the values that may be returned by the ScaleElement procedure.
 */

#define OTHER		0
#define TROUGH1		1
#define SLIDER		2
#define TROUGH2		3

/*
 * Space to leave between scale area and text, and between text and
 * edge of window.
 */

#define SPACING 2

/*
 * How many characters of space to provide when formatting the
 * scale's value:
 */

#define PRINT_CHARS 150

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

EXTERN void		TkEventuallyRedrawScale _ANSI_ARGS_((TkScale *scalePtr,
			    int what));
EXTERN double		TkRoundToResolution _ANSI_ARGS_((TkScale *scalePtr,
			    double value));
EXTERN TkScale *	TkpCreateScale _ANSI_ARGS_((Tk_Window tkwin));
EXTERN void		TkpDestroyScale _ANSI_ARGS_((TkScale *scalePtr));
EXTERN void		TkpDisplayScale _ANSI_ARGS_((ClientData clientData));
EXTERN double		TkpPixelToValue _ANSI_ARGS_((TkScale *scalePtr, 
			    int x, int y));
EXTERN int		TkpScaleElement _ANSI_ARGS_((TkScale *scalePtr,
			     int x, int y));
EXTERN void		TkpSetScaleValue _ANSI_ARGS_((TkScale *scalePtr,
			    double value, int setVar, int invokeCommand));
EXTERN int		TkpValueToPixel _ANSI_ARGS_((TkScale *scalePtr,
			    double value));

#endif /* _TKSCALE */
