Initial revision

1 files changed, 1143 insertions, 0 deletions

diff --git a/generic/tkScale.c b/generic/tkScale.c
new file mode 100644
index 0000000..6c78150
--- /dev/null
+++ b/generic/tkScale.c
@@ -0,0 +1,1143 @@
+/* 
+ * tkScale.c --
+ *
+ *	This module implements a scale widgets for the Tk toolkit.
+ *	A scale displays a slider that can be adjusted to change a
+ *	value;  it also displays numeric labels and a textual label,
+ *	if desired.
+ *	
+ *	The modifications to use floating-point values are based on
+ *	an implementation by Paul Mackerras.  The -variable option
+ *	is due to Henning Schulzrinne.  All of these are used with
+ *	permission.
+ *
+ * Copyright (c) 1990-1994 The Regents of the University of California.
+ * Copyright (c) 1994-1996 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.c 1.88 97/07/31 09:11:57
+ */
+
+#include "tkPort.h"
+#include "default.h"
+#include "tkInt.h"
+#include "tclMath.h"
+#include "tkScale.h"
+
+static Tk_ConfigSpec configSpecs[] = {
+    {TK_CONFIG_BORDER, "-activebackground", "activeBackground", "Foreground",
+	DEF_SCALE_ACTIVE_BG_COLOR, Tk_Offset(TkScale, activeBorder),
+	TK_CONFIG_COLOR_ONLY},
+    {TK_CONFIG_BORDER, "-activebackground", "activeBackground", "Foreground",
+	DEF_SCALE_ACTIVE_BG_MONO, Tk_Offset(TkScale, activeBorder),
+	TK_CONFIG_MONO_ONLY},
+    {TK_CONFIG_BORDER, "-background", "background", "Background",
+	DEF_SCALE_BG_COLOR, Tk_Offset(TkScale, bgBorder),
+	TK_CONFIG_COLOR_ONLY},
+    {TK_CONFIG_BORDER, "-background", "background", "Background",
+	DEF_SCALE_BG_MONO, Tk_Offset(TkScale, bgBorder),
+	TK_CONFIG_MONO_ONLY},
+    {TK_CONFIG_DOUBLE, "-bigincrement", "bigIncrement", "BigIncrement",
+	DEF_SCALE_BIG_INCREMENT, Tk_Offset(TkScale, bigIncrement), 0},
+    {TK_CONFIG_SYNONYM, "-bd", "borderWidth", (char *) NULL,
+	(char *) NULL, 0, 0},
+    {TK_CONFIG_SYNONYM, "-bg", "background", (char *) NULL,
+	(char *) NULL, 0, 0},
+    {TK_CONFIG_PIXELS, "-borderwidth", "borderWidth", "BorderWidth",
+	DEF_SCALE_BORDER_WIDTH, Tk_Offset(TkScale, borderWidth), 0},
+    {TK_CONFIG_STRING, "-command", "command", "Command",
+	DEF_SCALE_COMMAND, Tk_Offset(TkScale, command), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_ACTIVE_CURSOR, "-cursor", "cursor", "Cursor",
+	DEF_SCALE_CURSOR, Tk_Offset(TkScale, cursor), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_INT, "-digits", "digits", "Digits",
+	DEF_SCALE_DIGITS, Tk_Offset(TkScale, digits), 0},
+    {TK_CONFIG_SYNONYM, "-fg", "foreground", (char *) NULL,
+	(char *) NULL, 0, 0},
+    {TK_CONFIG_FONT, "-font", "font", "Font",
+	DEF_SCALE_FONT, Tk_Offset(TkScale, tkfont),
+	0},
+    {TK_CONFIG_COLOR, "-foreground", "foreground", "Foreground",
+	DEF_SCALE_FG_COLOR, Tk_Offset(TkScale, textColorPtr),
+	TK_CONFIG_COLOR_ONLY},
+    {TK_CONFIG_COLOR, "-foreground", "foreground", "Foreground",
+	DEF_SCALE_FG_MONO, Tk_Offset(TkScale, textColorPtr),
+	TK_CONFIG_MONO_ONLY},
+    {TK_CONFIG_DOUBLE, "-from", "from", "From",
+	DEF_SCALE_FROM, Tk_Offset(TkScale, fromValue), 0},
+    {TK_CONFIG_COLOR, "-highlightbackground", "highlightBackground",
+	"HighlightBackground", DEF_SCALE_HIGHLIGHT_BG,
+	Tk_Offset(TkScale, highlightBgColorPtr), 0},
+    {TK_CONFIG_COLOR, "-highlightcolor", "highlightColor", "HighlightColor",
+	DEF_SCALE_HIGHLIGHT, Tk_Offset(TkScale, highlightColorPtr), 0},
+    {TK_CONFIG_PIXELS, "-highlightthickness", "highlightThickness",
+	"HighlightThickness",
+	DEF_SCALE_HIGHLIGHT_WIDTH, Tk_Offset(TkScale, highlightWidth), 0},
+    {TK_CONFIG_STRING, "-label", "label", "Label",
+	DEF_SCALE_LABEL, Tk_Offset(TkScale, label), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_PIXELS, "-length", "length", "Length",
+	DEF_SCALE_LENGTH, Tk_Offset(TkScale, length), 0},
+    {TK_CONFIG_UID, "-orient", "orient", "Orient",
+	DEF_SCALE_ORIENT, Tk_Offset(TkScale, orientUid), 0},
+    {TK_CONFIG_RELIEF, "-relief", "relief", "Relief",
+	DEF_SCALE_RELIEF, Tk_Offset(TkScale, relief), 0},
+    {TK_CONFIG_INT, "-repeatdelay", "repeatDelay", "RepeatDelay",
+	DEF_SCALE_REPEAT_DELAY, Tk_Offset(TkScale, repeatDelay), 0},
+    {TK_CONFIG_INT, "-repeatinterval", "repeatInterval", "RepeatInterval",
+	DEF_SCALE_REPEAT_INTERVAL, Tk_Offset(TkScale, repeatInterval), 0},
+    {TK_CONFIG_DOUBLE, "-resolution", "resolution", "Resolution",
+	DEF_SCALE_RESOLUTION, Tk_Offset(TkScale, resolution), 0},
+    {TK_CONFIG_BOOLEAN, "-showvalue", "showValue", "ShowValue",
+	DEF_SCALE_SHOW_VALUE, Tk_Offset(TkScale, showValue), 0},
+    {TK_CONFIG_PIXELS, "-sliderlength", "sliderLength", "SliderLength",
+	DEF_SCALE_SLIDER_LENGTH, Tk_Offset(TkScale, sliderLength), 0},
+    {TK_CONFIG_RELIEF, "-sliderrelief", "sliderRelief", "SliderRelief",
+	DEF_SCALE_SLIDER_RELIEF, Tk_Offset(TkScale, sliderRelief),
+	TK_CONFIG_DONT_SET_DEFAULT},
+    {TK_CONFIG_UID, "-state", "state", "State",
+	DEF_SCALE_STATE, Tk_Offset(TkScale, state), 0},
+    {TK_CONFIG_STRING, "-takefocus", "takeFocus", "TakeFocus",
+	DEF_SCALE_TAKE_FOCUS, Tk_Offset(TkScale, takeFocus),
+	TK_CONFIG_NULL_OK},
+    {TK_CONFIG_DOUBLE, "-tickinterval", "tickInterval", "TickInterval",
+	DEF_SCALE_TICK_INTERVAL, Tk_Offset(TkScale, tickInterval), 0},
+    {TK_CONFIG_DOUBLE, "-to", "to", "To",
+	DEF_SCALE_TO, Tk_Offset(TkScale, toValue), 0},
+    {TK_CONFIG_COLOR, "-troughcolor", "troughColor", "Background",
+	DEF_SCALE_TROUGH_COLOR, Tk_Offset(TkScale, troughColorPtr),
+	TK_CONFIG_COLOR_ONLY},
+    {TK_CONFIG_COLOR, "-troughcolor", "troughColor", "Background",
+	DEF_SCALE_TROUGH_MONO, Tk_Offset(TkScale, troughColorPtr),
+	TK_CONFIG_MONO_ONLY},
+    {TK_CONFIG_STRING, "-variable", "variable", "Variable",
+	DEF_SCALE_VARIABLE, Tk_Offset(TkScale, varName), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_PIXELS, "-width", "width", "Width",
+	DEF_SCALE_WIDTH, Tk_Offset(TkScale, width), 0},
+    {TK_CONFIG_END, (char *) NULL, (char *) NULL, (char *) NULL,
+	(char *) NULL, 0, 0}
+};
+
+/*
+ * Forward declarations for procedures defined later in this file:
+ */
+
+static void		ComputeFormat _ANSI_ARGS_((TkScale *scalePtr));
+static void		ComputeScaleGeometry _ANSI_ARGS_((TkScale *scalePtr));
+static int		ConfigureScale _ANSI_ARGS_((Tcl_Interp *interp,
+			    TkScale *scalePtr, int argc, char **argv,
+			    int flags));
+static void		DestroyScale _ANSI_ARGS_((char *memPtr));
+static void		ScaleCmdDeletedProc _ANSI_ARGS_((
+			    ClientData clientData));
+static void		ScaleEventProc _ANSI_ARGS_((ClientData clientData,
+			    XEvent *eventPtr));
+static char *		ScaleVarProc _ANSI_ARGS_((ClientData clientData,
+			    Tcl_Interp *interp, char *name1, char *name2,
+			    int flags));
+static int		ScaleWidgetCmd _ANSI_ARGS_((ClientData clientData,
+			    Tcl_Interp *interp, int argc, char **argv));
+static void		ScaleWorldChanged _ANSI_ARGS_((
+			    ClientData instanceData));
+
+/*
+ * The structure below defines scale class behavior by means of procedures
+ * that can be invoked from generic window code.
+ */
+
+static TkClassProcs scaleClass = {
+    NULL,			/* createProc. */
+    ScaleWorldChanged,		/* geometryProc. */
+    NULL			/* modalProc. */
+};
+
+
+/*
+ *--------------------------------------------------------------
+ *
+ * Tk_ScaleCmd --
+ *
+ *	This procedure is invoked to process the "scale" Tcl
+ *	command.  See the user documentation for details on what
+ *	it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	See the user documentation.
+ *
+ *--------------------------------------------------------------
+ */
+
+int
+Tk_ScaleCmd(clientData, interp, argc, argv)
+    ClientData clientData;		/* Main window associated with
+				 * interpreter. */
+    Tcl_Interp *interp;		/* Current interpreter. */
+    int argc;			/* Number of arguments. */
+    char **argv;		/* Argument strings. */
+{
+    Tk_Window tkwin = (Tk_Window) clientData;
+    register TkScale *scalePtr;
+    Tk_Window new;
+
+    if (argc < 2) {
+	Tcl_AppendResult(interp, "wrong # args: should be \"",
+		argv[0], " pathName ?options?\"", (char *) NULL);
+	return TCL_ERROR;
+    }
+
+    new = Tk_CreateWindowFromPath(interp, tkwin, argv[1], (char *) NULL);
+    if (new == NULL) {
+	return TCL_ERROR;
+    }
+    scalePtr = TkpCreateScale(new);
+
+    /*
+     * Initialize fields that won't be initialized by ConfigureScale,
+     * or which ConfigureScale expects to have reasonable values
+     * (e.g. resource pointers).
+     */
+
+    scalePtr->tkwin = new;
+    scalePtr->display = Tk_Display(new);
+    scalePtr->interp = interp;
+    scalePtr->widgetCmd = Tcl_CreateCommand(interp,
+	    Tk_PathName(scalePtr->tkwin), ScaleWidgetCmd,
+	    (ClientData) scalePtr, ScaleCmdDeletedProc);
+    scalePtr->orientUid = NULL;
+    scalePtr->vertical = 0;
+    scalePtr->width = 0;
+    scalePtr->length = 0;
+    scalePtr->value = 0;
+    scalePtr->varName = NULL;
+    scalePtr->fromValue = 0;
+    scalePtr->toValue = 0;
+    scalePtr->tickInterval = 0;
+    scalePtr->resolution = 1;
+    scalePtr->bigIncrement = 0.0;
+    scalePtr->command = NULL;
+    scalePtr->repeatDelay = 0;
+    scalePtr->repeatInterval = 0;
+    scalePtr->label = NULL;
+    scalePtr->labelLength = 0;
+    scalePtr->state = tkNormalUid;
+    scalePtr->borderWidth = 0;
+    scalePtr->bgBorder = NULL;
+    scalePtr->activeBorder = NULL;
+    scalePtr->sliderRelief = TK_RELIEF_RAISED;
+    scalePtr->troughColorPtr = NULL;
+    scalePtr->troughGC = None;
+    scalePtr->copyGC = None;
+    scalePtr->tkfont = NULL;
+    scalePtr->textColorPtr = NULL;
+    scalePtr->textGC = None;
+    scalePtr->relief = TK_RELIEF_FLAT;
+    scalePtr->highlightWidth = 0;
+    scalePtr->highlightBgColorPtr = NULL;
+    scalePtr->highlightColorPtr = NULL;
+    scalePtr->inset = 0;
+    scalePtr->sliderLength = 0;
+    scalePtr->showValue = 0;
+    scalePtr->horizLabelY = 0;
+    scalePtr->horizValueY = 0;
+    scalePtr->horizTroughY = 0;
+    scalePtr->horizTickY = 0;
+    scalePtr->vertTickRightX = 0;
+    scalePtr->vertValueRightX = 0;
+    scalePtr->vertTroughX = 0;
+    scalePtr->vertLabelX = 0;
+    scalePtr->cursor = None;
+    scalePtr->takeFocus = NULL;
+    scalePtr->flags = NEVER_SET;
+
+    Tk_SetClass(scalePtr->tkwin, "Scale");
+    TkSetClassProcs(scalePtr->tkwin, &scaleClass, (ClientData) scalePtr);
+    Tk_CreateEventHandler(scalePtr->tkwin,
+	    ExposureMask|StructureNotifyMask|FocusChangeMask,
+	    ScaleEventProc, (ClientData) scalePtr);
+    if (ConfigureScale(interp, scalePtr, argc-2, argv+2, 0) != TCL_OK) {
+	goto error;
+    }
+
+    interp->result = Tk_PathName(scalePtr->tkwin);
+    return TCL_OK;
+
+    error:
+    Tk_DestroyWindow(scalePtr->tkwin);
+    return TCL_ERROR;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * ScaleWidgetCmd --
+ *
+ *	This procedure is invoked to process the Tcl command
+ *	that corresponds to a widget managed by this module.
+ *	See the user documentation for details on what it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	See the user documentation.
+ *
+ *--------------------------------------------------------------
+ */
+
+static int
+ScaleWidgetCmd(clientData, interp, argc, argv)
+    ClientData clientData;		/* Information about scale
+					 * widget. */
+    Tcl_Interp *interp;			/* Current interpreter. */
+    int argc;				/* Number of arguments. */
+    char **argv;			/* Argument strings. */
+{
+    register TkScale *scalePtr = (TkScale *) clientData;
+    int result = TCL_OK;
+    size_t length;
+    int c;
+
+    if (argc < 2) {
+	Tcl_AppendResult(interp, "wrong # args: should be \"",
+		argv[0], " option ?arg arg ...?\"", (char *) NULL);
+	return TCL_ERROR;
+    }
+    Tcl_Preserve((ClientData) scalePtr);
+    c = argv[1][0];
+    length = strlen(argv[1]);
+    if ((c == 'c') && (strncmp(argv[1], "cget", length) == 0)
+	    && (length >= 2)) {
+	if (argc != 3) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"",
+		    argv[0], " cget option\"",
+		    (char *) NULL);
+	    goto error;
+	}
+	result = Tk_ConfigureValue(interp, scalePtr->tkwin, configSpecs,
+		(char *) scalePtr, argv[2], 0);
+    } else if ((c == 'c') && (strncmp(argv[1], "configure", length) == 0)
+	    && (length >= 3)) {
+	if (argc == 2) {
+	    result = Tk_ConfigureInfo(interp, scalePtr->tkwin, configSpecs,
+		    (char *) scalePtr, (char *) NULL, 0);
+	} else if (argc == 3) {
+	    result = Tk_ConfigureInfo(interp, scalePtr->tkwin, configSpecs,
+		    (char *) scalePtr, argv[2], 0);
+	} else {
+	    result = ConfigureScale(interp, scalePtr, argc-2, argv+2,
+		    TK_CONFIG_ARGV_ONLY);
+	}
+    } else if ((c == 'c') && (strncmp(argv[1], "coords", length) == 0)
+	    && (length >= 3)) {
+	int x, y ;
+	double value;
+
+	if ((argc != 2) && (argc != 3)) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"",
+		    argv[0], " coords ?value?\"", (char *) NULL);
+	    goto error;
+	}
+	if (argc == 3) {
+	    if (Tcl_GetDouble(interp, argv[2], &value) != TCL_OK) {
+		goto error;
+	    }
+	} else {
+	    value = scalePtr->value;
+	}
+	if (scalePtr->vertical) {
+	    x = scalePtr->vertTroughX + scalePtr->width/2
+		    + scalePtr->borderWidth;
+	    y = TkpValueToPixel(scalePtr, value);
+	} else {
+	    x = TkpValueToPixel(scalePtr, value);
+	    y = scalePtr->horizTroughY + scalePtr->width/2
+		    + scalePtr->borderWidth;
+	}
+	sprintf(interp->result, "%d %d", x, y);
+    } else if ((c == 'g') && (strncmp(argv[1], "get", length) == 0)) {
+	double value;
+	int x, y;
+
+	if ((argc != 2) && (argc != 4)) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"",
+		    argv[0], " get ?x y?\"", (char *) NULL);
+	    goto error;
+	}
+	if (argc == 2) {
+	    value = scalePtr->value;
+	} else {
+	    if ((Tcl_GetInt(interp, argv[2], &x) != TCL_OK)
+		    || (Tcl_GetInt(interp, argv[3], &y) != TCL_OK)) {
+		goto error;
+	    }
+	    value = TkpPixelToValue(scalePtr, x, y);
+	}
+	sprintf(interp->result, scalePtr->format, value);
+    } else if ((c == 'i') && (strncmp(argv[1], "identify", length) == 0)) {
+	int x, y, thing;
+
+	if (argc != 4) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"",
+		    argv[0], " identify x y\"", (char *) NULL);
+	    goto error;
+	}
+	if ((Tcl_GetInt(interp, argv[2], &x) != TCL_OK)
+		|| (Tcl_GetInt(interp, argv[3], &y) != TCL_OK)) {
+	    goto error;
+	}
+	thing = TkpScaleElement(scalePtr, x,y);
+	switch (thing) {
+	    case TROUGH1:	interp->result = "trough1";	break;
+	    case SLIDER:	interp->result = "slider";	break;
+	    case TROUGH2:	interp->result = "trough2";	break;
+	}
+    } else if ((c == 's') && (strncmp(argv[1], "set", length) == 0)) {
+	double value;
+
+	if (argc != 3) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"",
+		    argv[0], " set value\"", (char *) NULL);
+	    goto error;
+	}
+	if (Tcl_GetDouble(interp, argv[2], &value) != TCL_OK) {
+	    goto error;
+	}
+	if (scalePtr->state != tkDisabledUid) {
+	    TkpSetScaleValue(scalePtr, value, 1, 1);
+	}
+    } else {
+	Tcl_AppendResult(interp, "bad option \"", argv[1],
+		"\": must be cget, configure, coords, get, identify, or set",
+		(char *) NULL);
+	goto error;
+    }
+    Tcl_Release((ClientData) scalePtr);
+    return result;
+
+    error:
+    Tcl_Release((ClientData) scalePtr);
+    return TCL_ERROR;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * DestroyScale --
+ *
+ *	This procedure is invoked by Tcl_EventuallyFree or Tcl_Release
+ *	to clean up the internal structure of a button at a safe time
+ *	(when no-one is using it anymore).
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Everything associated with the scale is freed up.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+DestroyScale(memPtr)
+    char *memPtr;	/* Info about scale widget. */
+{
+    register TkScale *scalePtr = (TkScale *) memPtr;
+
+    /*
+     * Free up all the stuff that requires special handling, then
+     * let Tk_FreeOptions handle all the standard option-related
+     * stuff.
+     */
+
+    if (scalePtr->varName != NULL) {
+	Tcl_UntraceVar(scalePtr->interp, scalePtr->varName,
+		TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
+		ScaleVarProc, (ClientData) scalePtr);
+    }
+    if (scalePtr->troughGC != None) {
+	Tk_FreeGC(scalePtr->display, scalePtr->troughGC);
+    }
+    if (scalePtr->copyGC != None) {
+	Tk_FreeGC(scalePtr->display, scalePtr->copyGC);
+    }
+    if (scalePtr->textGC != None) {
+	Tk_FreeGC(scalePtr->display, scalePtr->textGC);
+    }
+    Tk_FreeOptions(configSpecs, (char *) scalePtr, scalePtr->display, 0);
+    TkpDestroyScale(scalePtr);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * ConfigureScale --
+ *
+ *	This procedure is called to process an argv/argc list, plus
+ *	the Tk option database, in order to configure (or
+ *	reconfigure) a scale widget.
+ *
+ * Results:
+ *	The return value is a standard Tcl result.  If TCL_ERROR is
+ *	returned, then interp->result contains an error message.
+ *
+ * Side effects:
+ *	Configuration information, such as colors, border width,
+ *	etc. get set for scalePtr;  old resources get freed,
+ *	if there were any.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+ConfigureScale(interp, scalePtr, argc, argv, flags)
+    Tcl_Interp *interp;		/* Used for error reporting. */
+    register TkScale *scalePtr;	/* Information about widget;  may or may
+				 * not already have values for some fields. */
+    int argc;			/* Number of valid entries in argv. */
+    char **argv;		/* Arguments. */
+    int flags;			/* Flags to pass to Tk_ConfigureWidget. */
+{
+    size_t length;
+
+    /*
+     * Eliminate any existing trace on a variable monitored by the scale.
+     */
+
+    if (scalePtr->varName != NULL) {
+	Tcl_UntraceVar(interp, scalePtr->varName, 
+		TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
+		ScaleVarProc, (ClientData) scalePtr);
+    }
+
+    if (Tk_ConfigureWidget(interp, scalePtr->tkwin, configSpecs,
+	    argc, argv, (char *) scalePtr, flags) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * If the scale is tied to the value of a variable, then set up
+     * a trace on the variable's value and set the scale's value from
+     * the value of the variable, if it exists.
+     */
+
+    if (scalePtr->varName != NULL) {
+	char *stringValue, *end;
+	double value;
+
+	stringValue = Tcl_GetVar(interp, scalePtr->varName, TCL_GLOBAL_ONLY);
+	if (stringValue != NULL) {
+	    value = strtod(stringValue, &end);
+	    if ((end != stringValue) && (*end == 0)) {
+		scalePtr->value = TkRoundToResolution(scalePtr, value);
+	    }
+	}
+	Tcl_TraceVar(interp, scalePtr->varName,
+		TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
+		ScaleVarProc, (ClientData) scalePtr);
+    }
+
+    /*
+     * Several options need special processing, such as parsing the
+     * orientation and creating GCs.
+     */
+
+    length = strlen(scalePtr->orientUid);
+    if (strncmp(scalePtr->orientUid, "vertical", length) == 0) {
+	scalePtr->vertical = 1;
+    } else if (strncmp(scalePtr->orientUid, "horizontal", length) == 0) {
+	scalePtr->vertical = 0;
+    } else {
+	Tcl_AppendResult(interp, "bad orientation \"", scalePtr->orientUid,
+		"\": must be vertical or horizontal", (char *) NULL);
+	return TCL_ERROR;
+    }
+
+    scalePtr->fromValue = TkRoundToResolution(scalePtr, scalePtr->fromValue);
+    scalePtr->toValue = TkRoundToResolution(scalePtr, scalePtr->toValue);
+    scalePtr->tickInterval = TkRoundToResolution(scalePtr,
+	    scalePtr->tickInterval);
+
+    /*
+     * Make sure that the tick interval has the right sign so that
+     * addition moves from fromValue to toValue.
+     */
+
+    if ((scalePtr->tickInterval < 0)
+	    ^ ((scalePtr->toValue - scalePtr->fromValue) <  0)) {
+	scalePtr->tickInterval = -scalePtr->tickInterval;
+    }
+
+    /*
+     * Set the scale value to itself;  all this does is to make sure
+     * that the scale's value is within the new acceptable range for
+     * the scale and reflect the value in the associated variable,
+     * if any.
+     */
+
+    ComputeFormat(scalePtr);
+    TkpSetScaleValue(scalePtr, scalePtr->value, 1, 1);
+
+    if (scalePtr->label != NULL) {
+	scalePtr->labelLength = strlen(scalePtr->label);
+    } else {
+	scalePtr->labelLength = 0;
+    }
+
+    if ((scalePtr->state != tkNormalUid)
+	    && (scalePtr->state != tkDisabledUid)
+	    && (scalePtr->state != tkActiveUid)) {
+	Tcl_AppendResult(interp, "bad state value \"", scalePtr->state,
+		"\": must be normal, active, or disabled", (char *) NULL);
+	scalePtr->state = tkNormalUid;
+	return TCL_ERROR;
+    }
+
+    Tk_SetBackgroundFromBorder(scalePtr->tkwin, scalePtr->bgBorder);
+
+    if (scalePtr->highlightWidth < 0) {
+	scalePtr->highlightWidth = 0;
+    }
+    scalePtr->inset = scalePtr->highlightWidth + scalePtr->borderWidth;
+
+    ScaleWorldChanged((ClientData) scalePtr);
+    return TCL_OK;
+}
+
+/*
+ *---------------------------------------------------------------------------
+ *
+ * ScaleWorldChanged --
+ *
+ *      This procedure is called when the world has changed in some
+ *      way and the widget needs to recompute all its graphics contexts
+ *	and determine its new geometry.
+ *
+ * Results:
+ *      None.
+ *
+ * Side effects:
+ *      Scale will be relayed out and redisplayed.
+ *
+ *---------------------------------------------------------------------------
+ */
+ 
+static void
+ScaleWorldChanged(instanceData)
+    ClientData instanceData;	/* Information about widget. */
+{
+    XGCValues gcValues;
+    GC gc;
+    TkScale *scalePtr;
+
+    scalePtr = (TkScale *) instanceData;
+
+    gcValues.foreground = scalePtr->troughColorPtr->pixel;
+    gc = Tk_GetGC(scalePtr->tkwin, GCForeground, &gcValues);
+    if (scalePtr->troughGC != None) {
+	Tk_FreeGC(scalePtr->display, scalePtr->troughGC);
+    }
+    scalePtr->troughGC = gc;
+
+    gcValues.font = Tk_FontId(scalePtr->tkfont);
+    gcValues.foreground = scalePtr->textColorPtr->pixel;
+    gc = Tk_GetGC(scalePtr->tkwin, GCForeground | GCFont, &gcValues);
+    if (scalePtr->textGC != None) {
+	Tk_FreeGC(scalePtr->display, scalePtr->textGC);
+    }
+    scalePtr->textGC = gc;
+
+    if (scalePtr->copyGC == None) {
+	gcValues.graphics_exposures = False;
+	scalePtr->copyGC = Tk_GetGC(scalePtr->tkwin, GCGraphicsExposures,
+	    &gcValues);
+    }
+    scalePtr->inset = scalePtr->highlightWidth + scalePtr->borderWidth;
+
+    /*
+     * Recompute display-related information, and let the geometry
+     * manager know how much space is needed now.
+     */
+
+    ComputeScaleGeometry(scalePtr);
+
+    TkEventuallyRedrawScale(scalePtr, REDRAW_ALL);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * ComputeFormat --
+ *
+ *	This procedure is invoked to recompute the "format" field
+ *	of a scale's widget record, which determines how the value
+ *	of the scale is converted to a string.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The format field of scalePtr is modified.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+ComputeFormat(scalePtr)
+    TkScale *scalePtr;			/* Information about scale widget. */
+{
+    double maxValue, x;
+    int mostSigDigit, numDigits, leastSigDigit, afterDecimal;
+    int eDigits, fDigits;
+
+    /*
+     * Compute the displacement from the decimal of the most significant
+     * digit required for any number in the scale's range.
+     */
+
+    maxValue = fabs(scalePtr->fromValue);
+    x = fabs(scalePtr->toValue);
+    if (x > maxValue) {
+	maxValue = x;
+    }
+    if (maxValue == 0) {
+	maxValue = 1;
+    }
+    mostSigDigit = (int) floor(log10(maxValue));
+
+    /*
+     * If the number of significant digits wasn't specified explicitly,
+     * compute it. It's the difference between the most significant
+     * digit needed to represent any number on the scale and the
+     * most significant digit of the smallest difference between
+     * numbers on the scale.  In other words, display enough digits so
+     * that at least one digit will be different between any two adjacent
+     * positions of the scale.
+     */
+
+    numDigits = scalePtr->digits;
+    if (numDigits <= 0) {
+	if  (scalePtr->resolution > 0) {
+	    /*
+	     * A resolution was specified for the scale, so just use it.
+	     */
+
+	    leastSigDigit = (int) floor(log10(scalePtr->resolution));
+	} else {
+	    /*
+	     * No resolution was specified, so compute the difference
+	     * in value between adjacent pixels and use it for the least
+	     * significant digit.
+	     */
+
+	    x = fabs(scalePtr->fromValue - scalePtr->toValue);
+	    if (scalePtr->length > 0) {
+		x /= scalePtr->length;
+	    }
+	    if (x > 0){
+		leastSigDigit = (int) floor(log10(x));
+	    } else {
+		leastSigDigit = 0;
+	    }
+	}
+	numDigits = mostSigDigit - leastSigDigit + 1;
+	if (numDigits < 1) {
+	    numDigits = 1;
+	}
+    }
+
+    /*
+     * Compute the number of characters required using "e" format and
+     * "f" format, and then choose whichever one takes fewer characters.
+     */
+
+    eDigits = numDigits + 4;
+    if (numDigits > 1) {
+	eDigits++;			/* Decimal point. */
+    }
+    afterDecimal = numDigits - mostSigDigit - 1;
+    if (afterDecimal < 0) {
+	afterDecimal = 0;
+    }
+    fDigits = (mostSigDigit >= 0) ? mostSigDigit + afterDecimal : afterDecimal;
+    if (afterDecimal > 0) {
+	fDigits++;			/* Decimal point. */
+    }
+    if (mostSigDigit < 0) {
+	fDigits++;			/* Zero to left of decimal point. */
+    }
+    if (fDigits <= eDigits) {
+	sprintf(scalePtr->format, "%%.%df", afterDecimal);
+    } else {
+	sprintf(scalePtr->format, "%%.%de", numDigits-1);
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * ComputeScaleGeometry --
+ *
+ *	This procedure is called to compute various geometrical
+ *	information for a scale, such as where various things get
+ *	displayed.  It's called when the window is reconfigured.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Display-related numbers get changed in *scalePtr.  The
+ *	geometry manager gets told about the window's preferred size.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+ComputeScaleGeometry(scalePtr)
+    register TkScale *scalePtr;		/* Information about widget. */
+{
+    char valueString[PRINT_CHARS];
+    int tmp, valuePixels, x, y, extraSpace;
+    Tk_FontMetrics fm;
+
+    /*
+     * Horizontal scales are simpler than vertical ones because
+     * all sizes are the same (the height of a line of text);
+     * handle them first and then quit.
+     */
+
+    Tk_GetFontMetrics(scalePtr->tkfont, &fm);
+    if (!scalePtr->vertical) {
+	y = scalePtr->inset;
+	extraSpace = 0;
+	if (scalePtr->labelLength != 0) {
+	    scalePtr->horizLabelY = y + SPACING;
+	    y += fm.linespace + SPACING;
+	    extraSpace = SPACING;
+	}
+	if (scalePtr->showValue) {
+	    scalePtr->horizValueY = y + SPACING;
+	    y += fm.linespace + SPACING;
+	    extraSpace = SPACING;
+	} else {
+	    scalePtr->horizValueY = y;
+	}
+	y += extraSpace;
+	scalePtr->horizTroughY = y;
+	y += scalePtr->width + 2*scalePtr->borderWidth;
+	if (scalePtr->tickInterval != 0) {
+	    scalePtr->horizTickY = y + SPACING;
+	    y += fm.linespace + 2*SPACING;
+	}
+	Tk_GeometryRequest(scalePtr->tkwin,
+		scalePtr->length + 2*scalePtr->inset, y + scalePtr->inset);
+	Tk_SetInternalBorder(scalePtr->tkwin, scalePtr->inset);
+	return;
+    }
+
+    /*
+     * Vertical scale:  compute the amount of space needed to display
+     * the scales value by formatting strings for the two end points;
+     * use whichever length is longer.
+     */
+
+    sprintf(valueString, scalePtr->format, scalePtr->fromValue);
+    valuePixels = Tk_TextWidth(scalePtr->tkfont, valueString, -1);
+
+    sprintf(valueString, scalePtr->format, scalePtr->toValue);
+    tmp = Tk_TextWidth(scalePtr->tkfont, valueString, -1);
+    if (valuePixels < tmp) {
+	valuePixels = tmp;
+    }
+
+    /*
+     * Assign x-locations to the elements of the scale, working from
+     * left to right.
+     */
+
+    x = scalePtr->inset;
+    if ((scalePtr->tickInterval != 0) && (scalePtr->showValue)) {
+	scalePtr->vertTickRightX = x + SPACING + valuePixels;
+	scalePtr->vertValueRightX = scalePtr->vertTickRightX + valuePixels
+		+ fm.ascent/2;
+	x = scalePtr->vertValueRightX + SPACING;
+    } else if (scalePtr->tickInterval != 0) {
+	scalePtr->vertTickRightX = x + SPACING + valuePixels;
+	scalePtr->vertValueRightX = scalePtr->vertTickRightX;
+	x = scalePtr->vertTickRightX + SPACING;
+    } else if (scalePtr->showValue) {
+	scalePtr->vertTickRightX = x;
+	scalePtr->vertValueRightX = x + SPACING + valuePixels;
+	x = scalePtr->vertValueRightX + SPACING;
+    } else {
+	scalePtr->vertTickRightX = x;
+	scalePtr->vertValueRightX = x;
+    }
+    scalePtr->vertTroughX = x;
+    x += 2*scalePtr->borderWidth + scalePtr->width;
+    if (scalePtr->labelLength == 0) {
+	scalePtr->vertLabelX = 0;
+    } else {
+	scalePtr->vertLabelX = x + fm.ascent/2;
+	x = scalePtr->vertLabelX + fm.ascent/2
+		+ Tk_TextWidth(scalePtr->tkfont, scalePtr->label,
+			scalePtr->labelLength);
+    }
+    Tk_GeometryRequest(scalePtr->tkwin, x + scalePtr->inset,
+	    scalePtr->length + 2*scalePtr->inset);
+    Tk_SetInternalBorder(scalePtr->tkwin, scalePtr->inset);
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * ScaleEventProc --
+ *
+ *	This procedure is invoked by the Tk dispatcher for various
+ *	events on scales.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	When the window gets deleted, internal structures get
+ *	cleaned up.  When it gets exposed, it is redisplayed.
+ *
+ *--------------------------------------------------------------
+ */
+
+static void
+ScaleEventProc(clientData, eventPtr)
+    ClientData clientData;	/* Information about window. */
+    XEvent *eventPtr;		/* Information about event. */
+{
+    TkScale *scalePtr = (TkScale *) clientData;
+
+    if ((eventPtr->type == Expose) && (eventPtr->xexpose.count == 0)) {
+	TkEventuallyRedrawScale(scalePtr, REDRAW_ALL);
+    } else if (eventPtr->type == DestroyNotify) {
+	if (scalePtr->tkwin != NULL) {
+	    scalePtr->tkwin = NULL;
+	    Tcl_DeleteCommandFromToken(scalePtr->interp, scalePtr->widgetCmd);
+	}
+	if (scalePtr->flags & REDRAW_ALL) {
+	    Tcl_CancelIdleCall(TkpDisplayScale, (ClientData) scalePtr);
+	}
+	Tcl_EventuallyFree((ClientData) scalePtr, DestroyScale);
+    } else if (eventPtr->type == ConfigureNotify) {
+	ComputeScaleGeometry(scalePtr);
+	TkEventuallyRedrawScale(scalePtr, REDRAW_ALL);
+    } else if (eventPtr->type == FocusIn) {
+	if (eventPtr->xfocus.detail != NotifyInferior) {
+	    scalePtr->flags |= GOT_FOCUS;
+	    if (scalePtr->highlightWidth > 0) {
+		TkEventuallyRedrawScale(scalePtr, REDRAW_ALL);
+	    }
+	}
+    } else if (eventPtr->type == FocusOut) {
+	if (eventPtr->xfocus.detail != NotifyInferior) {
+	    scalePtr->flags &= ~GOT_FOCUS;
+	    if (scalePtr->highlightWidth > 0) {
+		TkEventuallyRedrawScale(scalePtr, REDRAW_ALL);
+	    }
+	}
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * ScaleCmdDeletedProc --
+ *
+ *	This procedure is invoked when a widget command is deleted.  If
+ *	the widget isn't already in the process of being destroyed,
+ *	this command destroys it.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The widget is destroyed.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+ScaleCmdDeletedProc(clientData)
+    ClientData clientData;	/* Pointer to widget record for widget. */
+{
+    TkScale *scalePtr = (TkScale *) clientData;
+    Tk_Window tkwin = scalePtr->tkwin;
+
+    /*
+     * This procedure could be invoked either because the window was
+     * destroyed and the command was then deleted (in which case tkwin
+     * is NULL) or because the command was deleted, and then this procedure
+     * destroys the widget.
+     */
+
+    if (tkwin != NULL) {
+	scalePtr->tkwin = NULL;
+	Tk_DestroyWindow(tkwin);
+    }
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * TkEventuallyRedrawScale --
+ *
+ *	Arrange for part or all of a scale widget to redrawn at
+ *	the next convenient time in the future.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	If "what" is REDRAW_SLIDER then just the slider and the
+ *	value readout will be redrawn;  if "what" is REDRAW_ALL
+ *	then the entire widget will be redrawn.
+ *
+ *--------------------------------------------------------------
+ */
+
+void
+TkEventuallyRedrawScale(scalePtr, what)
+    register TkScale *scalePtr;	/* Information about widget. */
+    int what;			/* What to redraw:  REDRAW_SLIDER
+				 * or REDRAW_ALL. */
+{
+    if ((what == 0) || (scalePtr->tkwin == NULL)
+	    || !Tk_IsMapped(scalePtr->tkwin)) {
+	return;
+    }
+    if ((scalePtr->flags & REDRAW_ALL) == 0) {
+	Tcl_DoWhenIdle(TkpDisplayScale, (ClientData) scalePtr);
+    }
+    scalePtr->flags |= what;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * TkRoundToResolution --
+ *
+ *	Round a given floating-point value to the nearest multiple
+ *	of the scale's resolution.
+ *
+ * Results:
+ *	The return value is the rounded result.
+ *
+ * Side effects:
+ *	None.
+ *
+ *--------------------------------------------------------------
+ */
+
+double
+TkRoundToResolution(scalePtr, value)
+    TkScale *scalePtr;		/* Information about scale widget. */
+    double value;		/* Value to round. */
+{
+    double rem, new;
+
+    if (scalePtr->resolution <= 0) {
+	return value;
+    }
+    new = scalePtr->resolution * floor(value/scalePtr->resolution);
+    rem = value - new;
+    if (rem < 0) {
+	if (rem <= -scalePtr->resolution/2) {
+	    new -= scalePtr->resolution;
+	}
+    } else {
+	if (rem >= scalePtr->resolution/2) {
+	    new += scalePtr->resolution;
+	}
+    }
+    return new;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * ScaleVarProc --
+ *
+ *	This procedure is invoked by Tcl whenever someone modifies a
+ *	variable associated with a scale widget.
+ *
+ * Results:
+ *	NULL is always returned.
+ *
+ * Side effects:
+ *	The value displayed in the scale will change to match the
+ *	variable's new value.  If the variable has a bogus value then
+ *	it is reset to the value of the scale.
+ *
+ *----------------------------------------------------------------------
+ */
+
+    /* ARGSUSED */
+static char *
+ScaleVarProc(clientData, interp, name1, name2, flags)
+    ClientData clientData;	/* Information about button. */
+    Tcl_Interp *interp;		/* Interpreter containing variable. */
+    char *name1;		/* Name of variable. */
+    char *name2;		/* Second part of variable name. */
+    int flags;			/* Information about what happened. */
+{
+    register TkScale *scalePtr = (TkScale *) clientData;
+    char *stringValue, *end, *result;
+    double value;
+
+    /*
+     * If the variable is unset, then immediately recreate it unless
+     * the whole interpreter is going away.
+     */
+
+    if (flags & TCL_TRACE_UNSETS) {
+	if ((flags & TCL_TRACE_DESTROYED) && !(flags & TCL_INTERP_DESTROYED)) {
+	    Tcl_TraceVar(interp, scalePtr->varName,
+		    TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
+		    ScaleVarProc, clientData);
+	    scalePtr->flags |= NEVER_SET;
+	    TkpSetScaleValue(scalePtr, scalePtr->value, 1, 0);
+	}
+	return (char *) NULL;
+    }
+
+    /*
+     * If we came here because we updated the variable (in TkpSetScaleValue),
+     * then ignore the trace.  Otherwise update the scale with the value
+     * of the variable.
+     */
+
+    if (scalePtr->flags & SETTING_VAR) {
+	return (char *) NULL;
+    }
+    result = NULL;
+    stringValue = Tcl_GetVar(interp, scalePtr->varName, TCL_GLOBAL_ONLY);
+    if (stringValue != NULL) {
+	value = strtod(stringValue, &end);
+	if ((end == stringValue) || (*end != 0)) {
+	    result = "can't assign non-numeric value to scale variable";
+	} else {
+	    scalePtr->value = TkRoundToResolution(scalePtr, value);
+	}
+
+	/*
+	 * This code is a bit tricky because it sets the scale's value before
+	 * calling TkpSetScaleValue.  This way, TkpSetScaleValue won't bother 
+	 * to set the variable again or to invoke the -command.  However, it
+	 * also won't redisplay the scale, so we have to ask for that
+	 * explicitly.
+	 */
+
+	TkpSetScaleValue(scalePtr, scalePtr->value, 1, 0);
+	TkEventuallyRedrawScale(scalePtr, REDRAW_SLIDER);
+    }
+
+    return result;
+}