--- a/ListView.st	Sat Jul 25 12:15:35 1998 +0200
+++ b/ListView.st	Mon Jul 27 09:56:03 1998 +0200
@@ -591,12 +591,25 @@
 at:index put:aString
     "change a line and redisplay"
 
-    |visibleLine y|
-
+    |visibleLine y fontHeightBefore|
+
+    fontHeightBefore := fontHeight.
     self withoutRedrawAt:index put:aString.
+
     shown ifTrue:[
-        "/ synchronous:
-        self redrawLine:index
+        "/ synchronous drawing:
+
+        "/ this could have changed the font height;
+        "/ must clear all below last line, if it became smaller
+        fontHeightBefore > fontHeight ifTrue:[
+            (self listLineIsVisible:(self size)) ifTrue:[
+                self clearRectangle:(margin @ (self yOfVisibleLine:nLinesShown+1))
+                                    corner:(width-margin) @ (height-margin).
+            ].
+            self redrawFromLine:index
+        ] ifFalse:[
+            self redrawLine:index
+        ].
 
         "/ asynchronous:
 "/        visibleLine := self listLineToVisibleLine:index.
@@ -606,7 +619,7 @@
 "/        ].
     ]
 
-    "Modified: 18.4.1997 / 14:52:28 / cg"
+    "Modified: / 26.7.1998 / 13:36:33 / cg"
 !
 
 characterAtLine:lineNr col:colNr
@@ -725,7 +738,7 @@
      otherwise, take the information from the nonStrings arg.
      (the nonStrings information is remembered to optimize later redraws & height computations)."
 
-    |oldFirst oldLeft nonStringsBefore|
+    |oldFirst oldLeft nonStringsBefore fontHeightBefore|
 
     (aCollection isNil and:[list isNil]) ifTrue:[
         "no change"
@@ -736,6 +749,7 @@
     list := aCollection.
 
     nonStringsBefore := includesNonStrings.
+    fontHeightBefore := fontHeight.
     includesNonStrings := false.
 
     list notNil ifTrue:[
@@ -749,7 +763,9 @@
             ]
         ].
     ].
-    (includesNonStrings ~~ nonStringsBefore) ifTrue:[self getFontParameters].
+    (includesNonStrings ~~ nonStringsBefore) ifTrue:[
+        self getFontParameters.
+    ].
 
     widthOfWidestLine := nil.   "/ i.e. unknown
     oldFirst := firstLineShown.
@@ -758,10 +774,12 @@
     leftOffset := 0.
 
     realized ifTrue:[
-        self computeNumberOfLinesShown.
+        (includesNonStrings ~~ nonStringsBefore) ifTrue:[
+            self computeNumberOfLinesShown.
+        ].
         self contentsChanged.
         "
-         dont use scroll here to avoid the redraw
+         dont use scroll here to avoid double redraw
         "
         viewOrigin := 0 @ 0.
 
@@ -769,13 +787,20 @@
             self originChanged:0 @ ((oldFirst - 1) * fontHeight negated).
         ].
         shown ifTrue:[
-            self redrawFromVisibleLine:1 to:nLinesShown
+            self redrawFromVisibleLine:1 to:nLinesShown.
+
+            fontHeightBefore > fontHeight ifTrue:[
+                (self listLineIsVisible:(self size)) ifTrue:[
+"/                    self clearRectangle:((margin @ (self yOfVisibleLine:nLinesShown+1))
+"/                                        corner:(width-margin) @ (height-margin)).
+                ].
+            ]
         ]
     ]
 
-    "Modified: 30.8.1995 / 19:07:13 / claus"
-    "Modified: 5.6.1997 / 11:09:56 / cg"
-    "Created: 5.6.1997 / 12:40:06 / cg"
+    "Modified: / 30.8.1995 / 19:07:13 / claus"
+    "Created: / 5.6.1997 / 12:40:06 / cg"
+    "Modified: / 26.7.1998 / 13:47:35 / cg"
 !
 
 removeIndex:lineNr
@@ -913,7 +938,10 @@
             includesNonStrings := (list findFirst:[:e | e isString not]) ~~ 0.
         ].
     ].
-    (includesNonStrings ~~ nonStringsBefore) ifTrue:[self getFontParameters].
+    (includesNonStrings ~~ nonStringsBefore) ifTrue:[
+        self getFontParameters.
+        self computeNumberOfLinesShown.
+    ].
 
 "/ new - reposition horizontally if too big
     widthOfWidestLine := nil.   "/ i.e. unknown
@@ -963,8 +991,8 @@
     ]
 
     "Modified: / 18.12.1995 / 23:27:54 / stefan"
-    "Modified: / 6.3.1997 / 15:23:37 / cg"
     "Created: / 22.4.1998 / 11:11:51 / cg"
+    "Modified: / 26.7.1998 / 13:46:49 / cg"
 !
 
 size
@@ -1004,10 +1032,11 @@
 withoutRedrawAt:index put:aString
     "change a line without redisplay"
 
-    |w|
+    |w didIncludeNonStrings|
 
     self checkForExistingLine:index.
     list at:index put:aString.
+    didIncludeNonStrings := includesNonStrings.
     includesNonStrings ifFalse:[
         includesNonStrings := (aString notNil and:[aString isString not]).
     ] ifTrue:[
@@ -1016,6 +1045,11 @@
         ]
     ].
 
+    includesNonStrings ~~ didIncludeNonStrings ifTrue:[
+        self getFontParameters.
+        self computeNumberOfLinesShown
+    ].
+
     widthOfWidestLine notNil ifTrue:[
         aString isString ifTrue:[
             w := font widthOf:aString
@@ -1029,7 +1063,7 @@
         ].
     ]
 
-    "Modified: 22.10.1996 / 23:19:29 / cg"
+    "Modified: / 26.7.1998 / 13:00:14 / cg"
 ! !
 
 !ListView methodsFor:'accessing-mvc'!
@@ -2068,6 +2102,19 @@
     ^ line copyTo:stop
 !
 
+listLineIsVisible:listLineNr
+    "return true,  if a particular line is visible"
+
+    |visibleLineNr "{ Class: SmallInteger }"|
+
+    shown ifFalse:[^ false].
+    listLineNr isNil ifTrue:[^ false].
+    visibleLineNr := listLineNr + 1 - firstLineShown.
+    ^ (visibleLineNr between:1 and:nLinesShown)
+
+    "Created: / 26.7.1998 / 13:24:16 / cg"
+!
+
 listLineToVisibleLine:listLineNr
     "given a list line (1..) return visible linenr or nil"
 
@@ -2246,6 +2293,15 @@
     "Modified: 19.7.1996 / 20:38:54 / cg"
 !
 
+yOfLine:lineNr
+    "given a physical lineNr, return y-coordinate in view
+     - works for fix-height fonts only"
+
+    ^ self yOfVisibleLine:(self listLineToVisibleLine:lineNr)
+
+    "Created: / 26.7.1998 / 13:23:16 / cg"
+!
+
 yOfVisibleLine:visLineNr
     "given a visible lineNr, return y-coordinate in view
      - works for fix-height fonts only"
@@ -3704,5 +3760,5 @@
 !ListView class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libwidg/ListView.st,v 1.169 1998-06-18 17:07:55 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libwidg/ListView.st,v 1.170 1998-07-27 07:56:03 cg Exp $'
 ! !