Eliminate trailing zeros from scale tick values. This is done by

calculating a separate format string for these values, rather than
using the same format string as for the current value. The basis is
the same, i.e., enough digits are displayed to distinguish any pair of
adjacent tick values, and all tick values have the same number of
decimals so some may still have trailing zeros.

Code for laying out vertical scales has been adjusted to take account
of the fact that the tick column may now be narrower than the value
column.

1 files changed, 16 insertions, 12 deletions

diff --git a/unix/tkUnixScale.c b/unix/tkUnixScale.c
index 2009288..f5e3fc2 100644
--- a/unix/tkUnixScale.c
+++ b/unix/tkUnixScale.c
@@ -24,11 +24,13 @@
 static void		DisplayHorizontalScale(TkScale *scalePtr,
 			    Drawable drawable, XRectangle *drawnAreaPtr);
 static void		DisplayHorizontalValue(TkScale *scalePtr,
-			    Drawable drawable, double value, int top);
+			    Drawable drawable, double value,
+			    int top, char* format);
 static void		DisplayVerticalScale(TkScale *scalePtr,
 			    Drawable drawable, XRectangle *drawnAreaPtr);
 static void		DisplayVerticalValue(TkScale *scalePtr,
-			    Drawable drawable, double value, int rightEdge);
+			    Drawable drawable, double value, 
+			    int rightEdge, char* format);
 
 /*
  *----------------------------------------------------------------------
@@ -165,7 +167,7 @@ DisplayVerticalScale(
 		    }
 		}
 		DisplayVerticalValue(scalePtr, drawable, tickValue,
-			scalePtr->vertTickRightX);
+			scalePtr->vertTickRightX, scalePtr->tickFormat);
 	    }
 	}
     }
@@ -176,7 +178,7 @@ DisplayVerticalScale(
 
     if (scalePtr->showValue) {
 	DisplayVerticalValue(scalePtr, drawable, scalePtr->value,
-		scalePtr->vertValueRightX);
+	        scalePtr->vertValueRightX, scalePtr->valueFormat);
     }
 
     /*
@@ -261,8 +263,9 @@ DisplayVerticalValue(
     double value,		/* Y-coordinate of number to display,
 				 * specified in application coords, not in
 				 * pixels (we'll compute pixels). */
-    int rightEdge)		/* X-coordinate of right edge of text,
+    int rightEdge,		/* X-coordinate of right edge of text,
 				 * specified in pixels. */
+    char* format)               /* Format string to use for the value */
 {
     register Tk_Window tkwin = scalePtr->tkwin;
     int y, width, length;
@@ -271,7 +274,7 @@ DisplayVerticalValue(
 
     Tk_GetFontMetrics(scalePtr->tkfont, &fm);
     y = TkScaleValueToPixel(scalePtr, value) + fm.ascent/2;
-    if (snprintf(valueString, TCL_DOUBLE_SPACE, scalePtr->format, value) < 0) {
+    if (snprintf(valueString, TCL_DOUBLE_SPACE, format, value) < 0) {
         valueString[TCL_DOUBLE_SPACE - 1] = '\0';
     }
     length = (int) strlen(valueString);
@@ -358,7 +361,7 @@ DisplayHorizontalScale(
 
 	    ticks = fabs((scalePtr->toValue - scalePtr->fromValue)
 		    / tickInterval);
-            if (snprintf(valueString, TCL_DOUBLE_SPACE, scalePtr->format,
+            if (snprintf(valueString, TCL_DOUBLE_SPACE, scalePtr->tickFormat,
                     scalePtr->fromValue) < 0) {
                 valueString[TCL_DOUBLE_SPACE - 1] = '\0';
             }
@@ -385,7 +388,7 @@ DisplayHorizontalScale(
 		    }
 		}
 		DisplayHorizontalValue(scalePtr, drawable, tickValue,
-			scalePtr->horizTickY);
+			scalePtr->horizTickY, scalePtr->tickFormat);
 	    }
 	}
     }
@@ -396,7 +399,7 @@ DisplayHorizontalScale(
 
     if (scalePtr->showValue) {
 	DisplayHorizontalValue(scalePtr, drawable, scalePtr->value,
-		scalePtr->horizValueY);
+		scalePtr->horizValueY, scalePtr->valueFormat);
     }
 
     /*
@@ -482,8 +485,9 @@ DisplayHorizontalValue(
     double value,		/* X-coordinate of number to display,
 				 * specified in application coords, not in
 				 * pixels (we'll compute pixels). */
-    int top)			/* Y-coordinate of top edge of text, specified
+    int top,			/* Y-coordinate of top edge of text, specified
 				 * in pixels. */
+    char* format)               /* Format string to use for the value */
 {
     register Tk_Window tkwin = scalePtr->tkwin;
     int x, y, length, width;
@@ -493,7 +497,7 @@ DisplayHorizontalValue(
     x = TkScaleValueToPixel(scalePtr, value);
     Tk_GetFontMetrics(scalePtr->tkfont, &fm);
     y = top + fm.ascent;
-    if (snprintf(valueString, TCL_DOUBLE_SPACE, scalePtr->format, value) < 0) {
+    if (snprintf(valueString, TCL_DOUBLE_SPACE, format, value) < 0) {
         valueString[TCL_DOUBLE_SPACE - 1] = '\0';
     }
     length = (int) strlen(valueString);
@@ -562,7 +566,7 @@ TkpDisplayScale(
     Tcl_Preserve(scalePtr);
     if ((scalePtr->flags & INVOKE_COMMAND) && (scalePtr->command != NULL)) {
 	Tcl_Preserve(interp);
-        if (snprintf(string, TCL_DOUBLE_SPACE, scalePtr->format,
+        if (snprintf(string, TCL_DOUBLE_SPACE, scalePtr->valueFormat,
                 scalePtr->value) < 0) {
             string[TCL_DOUBLE_SPACE - 1] = '\0';
         }