* Remplacement de la convention qu'un texte vide est repr�sent�

	  par une chaine vide par un texte vide est repr�sent� par un
	  pointeur NULL.

2 files changed, 183 insertions, 117 deletions

diff --git a/generic/Field.c b/generic/Field.c
index 3cd5036..286e5fb 100644
--- a/generic/Field.c
+++ b/generic/Field.c
@@ -587,7 +587,10 @@ ComputeFieldTextLocation(Field		field_ptr,
   Tk_FontMetrics fm;
 
   Tk_GetFontMetrics(field_ptr->font, &fm);
-  w = ZnTextWidth(field_ptr->font, field_ptr->text, strlen(field_ptr->text));
+  w = 0;
+  if (field_ptr->text) {
+    w = ZnTextWidth(field_ptr->font, field_ptr->text, strlen(field_ptr->text));
+  }
   h = fm.ascent + fm.descent;
   text_bbox->orig.y = (bbox->orig.y + bbox->corner.y - h) / 2.0;
   text_bbox->corner.y = text_bbox->orig.y + h;
@@ -649,7 +652,7 @@ LeaderToLabel(FieldSet	field_set,
      * its own, don't clip.
      */
     if (ISCLEAR(field_ptr->flags, FIELD_VISIBLE_BIT) ||
-	((*field_ptr->text == 0) &&
+	(!field_ptr->text &&
 	 ISCLEAR(field_ptr->flags, FILLED_BIT) &&
 	 (field_ptr->border_edges == NO_BORDER) &&
 	 (field_ptr->relief == RELIEF_FLAT) &&
@@ -665,10 +668,9 @@ LeaderToLabel(FieldSet	field_set,
     /*
      * Adjust leader on real text, not on field boundaries. This is
      * important when there are leading and trailing spaces.
-     * The correct test here is really *field_ptr->text, an empty
-     * text is represented by an empty string NOT by a NULL pointer.
      */
-    if (*field_ptr->text && ISCLEAR(field_ptr->flags, FILLED_BIT) &&
+    if (field_ptr->text &&
+	ISCLEAR(field_ptr->flags, FILLED_BIT) &&
  	(field_ptr->border_edges == NO_BORDER) &&
 	(field_ptr->relief == RELIEF_FLAT) &&
  	(field_ptr->image == ZnUnspecifiedImage)) {
@@ -829,7 +831,7 @@ InitFields(FieldSet	field_set)
     CLEAR(field->flags, FILLED_BIT);
     CLEAR(field->flags, CACHE_OK);
     field->fill_pattern = ZnUnspecifiedImage;
-    field->text = "";
+    field->text = NULL;
     field->image = ZnUnspecifiedImage;
     field->tile = ZnUnspecifiedImage;
     field->font = Tk_GetFont(wi->interp, wi->win, Tk_NameOfFont(wi->font));
@@ -910,7 +912,7 @@ CloneFields(FieldSet	field_set)
     field->fill_color = ZnGetGradientByValue(field->fill_color);
     field->border_color = ZnGetGradientByValue(field->border_color);
 
-    if (strlen(field->text) != 0) {
+    if (field->text) {
       text = (char *) ZnMalloc((strlen(field->text) + 1) * sizeof(char));
       strcpy(text, field->text);
       field->text = text;
@@ -950,14 +952,20 @@ ConfigureField(FieldSet		fs,
   
   field_ptr = &fs->fields[field];
   old_font = field_ptr->font;
-  old_num_chars = strlen(field_ptr->text);
+  old_num_chars = 0;
+  if (field_ptr->text) {
+    old_num_chars = strlen(field_ptr->text);
+  }
 
   if (ZnConfigureAttributes(wi, field_ptr, field_attrs,
 			    argc, argv, flags) == ZN_ERROR) {
     return ZN_ERROR;
   }
 
-  num_chars = strlen(field_ptr->text);
+  num_chars = 0;
+  if (field_ptr->text) {
+    num_chars = strlen(field_ptr->text);
+  }
   if (old_num_chars != num_chars) {
     TextInfo *ti = &wi->text_info;
     /*
@@ -1086,7 +1094,7 @@ FreeFields(FieldSet	field_set)
   for (i = 0; i < num_fields; i++) {
     field = &field_set->fields[i];
     
-    if (strlen(field->text) != 0) {
+    if (field->text) {
       ZnFree(field->text);
     }
     if (field->gradient) {
@@ -1149,7 +1157,10 @@ FieldPointToChar(FieldSet	fs,
   int		n, dummy;
 
   field_ptr = &fs->fields[field];
-  num_chars = strlen(field_ptr->text);
+  num_chars = 0;
+  if (field_ptr->text) {
+    num_chars = strlen(field_ptr->text);
+  }
 
   if (num_chars == 0) {
     return 0;
@@ -1198,6 +1209,10 @@ WordMoveFromIndex(char	*text,
 {
   char	*strp;
 
+  if (!text) {
+    return index;
+  }
+
   if (fwd) {
     strp = &text[index];
     while ((strp[1] == ' ') || (strp[1] == '\n')) {
@@ -1241,7 +1256,10 @@ FieldIndex(FieldSet	fs,
   }
 
   field_ptr = &fs->fields[field];
-  num_chars = strlen(field_ptr->text);
+  num_chars = 0;
+  if (field_ptr->text) {
+    num_chars = strlen(field_ptr->text);
+  }
 
   p = Tcl_GetString(index_spec);
   c = p[0];
@@ -1346,7 +1364,10 @@ FieldInsertChars(FieldSet	fs,
   }
 
   field_ptr = &fs->fields[field];
-  num_chars = strlen(field_ptr->text);
+  num_chars = 0;
+  if (field_ptr->text) {
+    num_chars = strlen(field_ptr->text);
+  }
   if (*index < 0) {
     *index = 0;
   }
@@ -1355,10 +1376,19 @@ FieldInsertChars(FieldSet	fs,
   }
   
   new = ZnMalloc(num_chars + length + 1);
-  strncpy(new, field_ptr->text, (size_t) *index);
+  if (num_chars) {
+    /*
+     * Copy the part before and the part after the new
+     * text (if any).
+     */
+    strncpy(new, field_ptr->text, (size_t) *index);
+    strcpy(new + *index + length, field_ptr->text + *index);
+    ZnFree(field_ptr->text);
+  }
+  /*
+   * Insert the new text.
+   */
   strcpy(new + *index, chars);
-  strcpy(new + *index + length, field_ptr->text + *index);
-  ZnFree(field_ptr->text);
   field_ptr->text = new;
   
   if (field_ptr->insert_index >= *index) {
@@ -1387,7 +1417,10 @@ FieldDeleteChars(FieldSet	fs,
   }
 
   field_ptr = &fs->fields[field];
-  num_chars = strlen(field_ptr->text);
+  num_chars = 0;
+  if (field_ptr->text) {
+    num_chars = strlen(field_ptr->text);
+  }
   if (num_chars == 0) {
     return False;
   }
@@ -1403,11 +1436,17 @@ FieldDeleteChars(FieldSet	fs,
   }
   count = *last + 1 - *first;
 
-  new = ZnMalloc(num_chars + 1 - count);
-  strncpy(new, field_ptr->text, (size_t) *first);
-  strcpy(new + *first, field_ptr->text + *last + 1);
-  ZnFree(field_ptr->text);
-  field_ptr->text = new;
+  if (num_chars - count) {
+    new = ZnMalloc(num_chars + 1 - count);
+    strncpy(new, field_ptr->text, (size_t) *first);
+    strcpy(new + *first, field_ptr->text + *last + 1);
+    ZnFree(field_ptr->text);
+    field_ptr->text = new;
+  }
+  else {
+    ZnFree(field_ptr->text);
+    field_ptr->text = NULL;
+  }
 
   /*
    * Update the cursor to reflect the new string.
@@ -1439,7 +1478,10 @@ FieldCursor(FieldSet	fs,
   }
 
   field_ptr = &fs->fields[field];
-  num_chars = strlen(field_ptr->text);
+  num_chars = 0;
+  if (field_ptr->text) {
+    num_chars = strlen(field_ptr->text);
+  }
 
   if (index < 0) {
     field_ptr->insert_index = 0;
@@ -1473,7 +1515,10 @@ FieldSelection(FieldSet	fs,
     count = max_chars;
   }
   field_ptr = &fs->fields[field];
-  num_chars = strlen(field_ptr->text);
+  num_chars = 0;
+  if (field_ptr->text) {
+    num_chars = strlen(field_ptr->text);
+  }
   if (count > num_chars) {
     count = num_chars;
   }
@@ -1597,32 +1642,34 @@ FieldsEngine(FieldSet	field_set,
       restore |= val < 0;
 
       cursor = -1;
-      if ((field_set->item == wi->focus_item) && (wi->focus_field == i) &&
-	  wi->got_focus && ti->cursor_on) {
-	cursor = Tk_TextWidth(field_ptr->font, field_ptr->text,
-			      field_ptr->insert_index);
-      }
-      ComputeFieldTextLocation(field_ptr, &bbox, &text_pos, &text_bbox);
-      num_chars  = strlen(field_ptr->text);
-      if (num_chars) {
-	if ((field_set->item == ti->sel_item) && (ti->sel_field == i) &&
-	    (ti->sel_last >= 0) && (ti->sel_first <= num_chars)) {
-	  sel_start = Tk_TextWidth(field_ptr->font,
-				   field_ptr->text, ti->sel_first);
-	  sel_stop = Tk_TextWidth(field_ptr->font,
-				  field_ptr->text, ti->sel_last);
+      if (field_ptr->text) {
+	if ((field_set->item == wi->focus_item) &&
+	    (wi->focus_field == i) && wi->got_focus && ti->cursor_on) {
+	  cursor = Tk_TextWidth(field_ptr->font, field_ptr->text,
+				field_ptr->insert_index);
+	}
+	ComputeFieldTextLocation(field_ptr, &bbox, &text_pos, &text_bbox);
+	num_chars  = strlen(field_ptr->text);
+	if (num_chars) {
+	  if ((field_set->item == ti->sel_item) && (ti->sel_field == i) &&
+	      (ti->sel_last >= 0) && (ti->sel_first <= num_chars)) {
+	    sel_start = Tk_TextWidth(field_ptr->font,
+				     field_ptr->text, ti->sel_first);
+	    sel_stop = Tk_TextWidth(field_ptr->font,
+				    field_ptr->text, ti->sel_last);
+	  }
+	  
+	  IntersectBBox(&fclip_bbox, &text_bbox, &tmp_bbox);
+	  
+	  val = tmp_bbox.orig.x - text_bbox.orig.x;
+	  restore |= val > 0;
+	  val = tmp_bbox.orig.y - text_bbox.orig.y;
+	  restore |= val > 0;
+	  val = tmp_bbox.corner.x - text_bbox.corner.x;
+	  restore |= val < 0;
+	  val = tmp_bbox.corner.y - text_bbox.corner.y;
+	  restore |= val < 0;
 	}
-
-	IntersectBBox(&fclip_bbox, &text_bbox, &tmp_bbox);
-
-	val = tmp_bbox.orig.x - text_bbox.orig.x;
-	restore |= val > 0;
-	val = tmp_bbox.orig.y - text_bbox.orig.y;
-	restore |= val > 0;
-	val = tmp_bbox.corner.x - text_bbox.corner.x;
-	restore |= val < 0;
-	val = tmp_bbox.corner.y - text_bbox.corner.y;
-	restore |= val < 0;
       }
 
       if (field_ptr->image != ZnUnspecifiedImage) {
@@ -1761,7 +1808,7 @@ DrawField(WidgetInfo	*wi,
 	}
       }
     }
-    else {
+    else if (field_ptr->text) {
       /*
        * Draw the text.
        */
@@ -1941,7 +1988,7 @@ RenderField(WidgetInfo	*wi,
 		     &pm_bbox->orig, False);
       }
     }
-    else {
+    else if (field_ptr->text) {
       /*
        * Draw the text.
        */
diff --git a/generic/Text.c b/generic/Text.c
index 998d9ee..f9743bb 100644
--- a/generic/Text.c
+++ b/generic/Text.c
@@ -187,7 +187,7 @@ Init(Item		item,
   item->priority = DEFAULT_TEXT_PRIORITY;
 
   text->pos.x = text->pos.y = 0.0;
-  text->text = "";
+  text->text = NULL;
   text->num_chars = 0;
   text->fill_pattern = ZnUnspecifiedImage;
   text->anchor = ZnAnchorNW;
@@ -225,7 +225,7 @@ Clone(Item	item)
   WidgetInfo	*wi = item->wi;
   char		*str;
 
-  if (strlen(text->text) != 0) {
+  if (text->text) {
     str = ZnMalloc((strlen(text->text) + 1) * sizeof(char));
     strcpy(str, text->text);
     text->text = str;
@@ -264,7 +264,7 @@ Destroy(Item	item)
 {
   TextItem	text = (TextItem) item;
 
-  if (strlen(text->text) != 0) {
+  if (text->text) {
     ZnFree(text->text);
   }
   if (text->fill_pattern != ZnUnspecifiedImage) {
@@ -323,7 +323,10 @@ Configure(Item		item,
     }
   }
 #endif
-  num_chars = strlen(text->text);
+  num_chars = 0;
+  if (text->text) {
+    num_chars = strlen(text->text);
+  }
   if (text->num_chars != num_chars) {
     TextInfo *ti = &item->wi->text_info;
     /*
@@ -407,7 +410,7 @@ ComputeCoordinates(Item		item,
   int		font_height, height;
   
   ResetBBox(&item->item_bounding_box);
-
+  
   Tk_GetFontMetrics(text->font, &fm);
   font_height = fm.ascent+fm.descent;
   
@@ -436,53 +439,54 @@ ComputeCoordinates(Item		item,
       wrap = 100000;
     }
     
-    scan = text->text;
-    while (*scan) {
-      TextLineInfoStruct	info;
-      char			*ptr;
-      int			num;
-      
-      line_index = scan - text->text;
-      /*
-       * Limit the excursion of Tk_MeasureChars to the end
-       * of the line. Do not include \n in the measure done.
-       */
-      ptr = strchr(scan, '\n');
-      if (ptr) {
-	num = ptr-scan;
-      }
-      else {
-	num = strlen(scan);
-      }
-      info.num_chars = Tk_MeasureChars(text->font, scan, num, wrap,
-				       TK_WHOLE_WORDS|TK_AT_LEAST_ONE,
-				       &info.width);
-
-      info.start = scan;
-      text->max_width = MAX(info.width, text->max_width);
-      
-      scan += info.num_chars;
-      /*
-       * Adjust for the newline at the end of line.
-       */
-      if (ptr) {
-	scan++;
-      }
-
-      /* Build a line info even for an empty line
-       * at the end of text or for an empty text.
-       * It is needed to enable selection and cursor
-       * insertion to behave correctly.
-       */
-      ZnListAdd(text->text_info, &info, ZnListTail);
-      /*printf("adding a line : %s, num_chars :  %d, width : %d\n",
-	info.start, info.num_chars, info.width);*/
-      
-      /*
-       * Skip terminating space or return char if any.
-       */
-      if (isspace(*scan) || *scan == '\n') {
-	scan++;
+    if ((scan = text->text) != NULL) {
+      while (*scan) {
+	TextLineInfoStruct	info;
+	char			*ptr;
+	int			num;
+	
+	line_index = scan - text->text;
+	/*
+	 * Limit the excursion of Tk_MeasureChars to the end
+	 * of the line. Do not include \n in the measure done.
+	 */
+	ptr = strchr(scan, '\n');
+	if (ptr) {
+	  num = ptr-scan;
+	}
+	else {
+	  num = strlen(scan);
+	}
+	info.num_chars = Tk_MeasureChars(text->font, scan, num, wrap,
+					 TK_WHOLE_WORDS|TK_AT_LEAST_ONE,
+					 &info.width);
+	
+	info.start = scan;
+	text->max_width = MAX(info.width, text->max_width);
+	
+	scan += info.num_chars;
+	/*
+	 * Adjust for the newline at the end of line.
+	 */
+	if (ptr) {
+	  scan++;
+	}
+	
+	/* Build a line info even for an empty line
+	 * at the end of text or for an empty text.
+	 * It is needed to enable selection and cursor
+	 * insertion to behave correctly.
+	 */
+	ZnListAdd(text->text_info, &info, ZnListTail);
+	/*printf("adding a line : %s, num_chars :  %d, width : %d\n",
+	  info.start, info.num_chars, info.width);*/
+	
+	/*
+	 * Skip terminating space or return char if any.
+	 */
+	if (isspace(*scan) || *scan == '\n') {
+	  scan++;
+	}
       }
     }
   
@@ -581,7 +585,7 @@ ToArea(Item	item,
   ZnBBox	line_bbox, *area = ta->area;
   ZnPoint	o;
 
-  if (!text->text_info) {
+  if (!text->text_info || !text->text) {
     return -1;
   }
   
@@ -708,7 +712,7 @@ Draw(Item	item)
   int		sel_first_line=-1, sel_last_line=-1, cursor_line=-1;
   int		sel_start_offset=0, sel_stop_offset=0, cursor_offset=0;
 
-  if (!text->text_info) {
+  if (!text->text_info || !text->text) {
     return;
   }
   lines = (TextLineInfo) ZnListArray(text->text_info);
@@ -858,7 +862,7 @@ Render(Item	item)
   int		sel_first_line=-1, sel_last_line=-1, cursor_line=-1;
   int		sel_start_offset=0, sel_stop_offset=0, cursor_offset=0;
 
-  if (!text->text_info || !text->tfi) {
+  if (!text->text_info || !text->text || !text->tfi) {
     return;
   }
 
@@ -1037,7 +1041,7 @@ Pick(Item	item,
   ZnBBox	line_bbox;
   ZnPoint	o, *p = ps->point;
   
-  if (!text->text_info) {
+  if (!text->text_info || !text->text) {
     return dist;
   }
   
@@ -1263,7 +1267,7 @@ MoveFromIndex(TextItem	text,
   TextLineInfo	lines, p;
   char		*strp;
 
-  if (!text->text_info) {
+  if (!text->text_info || !text->text) {
     return index;
   }
   num_lines = ZnListSize(text->text_info);
@@ -1452,10 +1456,12 @@ InsertChars(Item	item,
   }
   
   new = ZnMalloc((unsigned) (text->num_chars + length + 1));
-  strncpy(new, text->text, (size_t) *index);
+  if (text->text) {
+    strncpy(new, text->text, (size_t) *index);
+    strcpy(new + *index + length, text->text + *index);
+    ZnFree(text->text);
+  }
   strcpy(new + *index, chars);
-  strcpy(new + *index + length, text->text + *index);
-  ZnFree(text->text);
   text->text = new;
   text->num_chars += length;
   
@@ -1484,6 +1490,9 @@ DeleteChars(Item	item,
   int		count;
   char		*new;
   
+  if (!text->text) {
+    return;
+  }
   if (*first < 0) {
     *first = 0;
   }
@@ -1495,12 +1504,19 @@ DeleteChars(Item	item,
   }
   count = *last + 1 - *first;
 
-  new = (char *) ZnMalloc((unsigned) (text->num_chars + 1 - count));
-  strncpy(new, text->text, (size_t) *first);
-  strcpy(new + *first, text->text + *last + 1);
-  ZnFree(text->text);
-  text->text = new;
-  text->num_chars -= count;
+  if (text->num_chars - count) {
+    new = (char *) ZnMalloc((unsigned) (text->num_chars + 1 - count));
+    strncpy(new, text->text, (size_t) *first);
+    strcpy(new + *first, text->text + *last + 1);
+    ZnFree(text->text);
+    text->text = new;
+    text->num_chars -= count;
+  }
+  else {
+    ZnFree(text->text);
+    text->text = NULL;
+    text->num_chars = 0;
+  }
 
   if (text->insert_index > *first) {
     text->insert_index -= count;
@@ -1558,6 +1574,9 @@ Selection(Item	item,
   TextInfo	*ti = &wi->text_info;
   int		count;
 
+  if (!text->text) {
+    return 0;
+  }
   count = ti->sel_last - ti->sel_first - offset;
   if (count > max_chars) {
     count = max_chars;