tkscale.c

linux系统下的音频通信

    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;
}