Fix [3089640fff], [6020ee2d03], [e016579efb], [6bf197edbf] and [7ffb9e554c]: ttk::notebook tabs can disappear (tab width incorrectly calculated), and -tabminwidth option of a style incorrect behaviour.

1 files changed, 24 insertions, 30 deletions

diff --git a/generic/ttk/ttkNotebook.c b/generic/ttk/ttkNotebook.c
index 81a8b64..b649e4b 100644
--- a/generic/ttk/ttkNotebook.c
+++ b/generic/ttk/ttkNotebook.c
@@ -4,6 +4,7 @@
 
 #include <string.h>
 #include <ctype.h>
+#include <math.h>
 #include <stdio.h>
 #include <tk.h>
 
@@ -325,6 +326,8 @@ static Ttk_State TabState(Notebook *nb, int index)
 /* TabrowSize --
  *	Compute max height and total width of all tabs (horizontal layouts)
  *	or total height and max width (vertical layouts).
+ *	The -mintabwidth style option is taken into account (for the width
+ *	only).
  *
  * Side effects:
  * 	Sets width and height fields for all tabs.
@@ -334,7 +337,7 @@ static Ttk_State TabState(Notebook *nb, int index)
  * 	(max height/width) but not parallel (total width/height).
  */
 static void TabrowSize(
-    Notebook *nb, Ttk_Orient orient, int *widthPtr, int *heightPtr)
+    Notebook *nb, Ttk_Orient orient, int minTabWidth, int *widthPtr, int *heightPtr)
 {
     Ttk_Layout tabLayout = nb->notebook.tabLayout;
     int tabrowWidth = 0, tabrowHeight = 0;
@@ -346,6 +349,7 @@ static void TabrowSize(
 
 	Ttk_RebindSublayout(tabLayout, tab);
 	Ttk_LayoutSize(tabLayout,tabState,&tab->width,&tab->height);
+        tab->width = MAX(tab->width, minTabWidth);
 
 	if (orient == TTK_ORIENT_HORIZONTAL) {
 	    tabrowHeight = MAX(tabrowHeight, tab->height);
@@ -406,7 +410,7 @@ static int NotebookSize(void *clientData, int *widthPtr, int *heightPtr)
 
     /* Tab row:
      */
-    TabrowSize(nb, nbstyle.tabOrient, &tabrowWidth, &tabrowHeight);
+    TabrowSize(nb, nbstyle.tabOrient, nbstyle.minTabWidth, &tabrowWidth, &tabrowHeight);
     tabrowHeight += Ttk_PaddingHeight(nbstyle.tabMargins);
     tabrowWidth += Ttk_PaddingWidth(nbstyle.tabMargins);
 
@@ -436,47 +440,32 @@ static int NotebookSize(void *clientData, int *widthPtr, int *heightPtr)
 
 /* SqueezeTabs --
  *	Squeeze or stretch tabs to fit within the tab area parcel.
+ *	This happens independently of the -mintabwidth style option.
  *
- *	All tabs are adjusted by an equal amount, but will not be made
- *	smaller than the minimum width.  (If all the tabs still do
- *	not fit in the available space, the rightmost ones will
- *	be further squozen by PlaceTabs()).
- *
- *	The algorithm does not always yield an optimal layout, but does
- *	have the important property that decreasing the available width
- *	by one pixel will cause at most one tab to shrink by one pixel;
- *	this means that tabs resize "smoothly" when the window shrinks
- *	and grows.
+ *	All tabs are adjusted by an equal amount.
  *
  * @@@ <<NOTE-TABPOSITION>> bug: only works for horizontal orientations
  * @@@ <<NOTE-SQUEEZE-HIDDEN>> does not account for hidden tabs.
  */
 
 static void SqueezeTabs(
-    Notebook *nb, int needed, int available, int minTabWidth)
+    Notebook *nb, int needed, int available)
 {
     int nTabs = Ttk_NumberSlaves(nb->notebook.mgr);
 
     if (nTabs > 0) {
-	int difference = available - needed,
-	    delta = difference / nTabs,
-	    remainder = difference % nTabs,
-	    slack = 0;
+	int difference = available - needed;
+	double fraction = (double)difference / needed;
+	double slack = 0;
+	double ad;
 	int i;
 
-	if (remainder < 0) { remainder += nTabs; --delta; }
-
 	for (i = 0; i < nTabs; ++i) {
 	    Tab *tab = Ttk_SlaveData(nb->notebook.mgr,i);
-	    int adj = delta + (i < remainder) + slack;
-
-	    if (tab->width + adj >= minTabWidth) {
-		tab->width += adj;
-		slack = 0;
-	    } else {
-		slack = adj - (minTabWidth - tab->width);
-		tab->width = minTabWidth;
-	    }
+
+	    ad = slack + tab->width * fraction;
+	    tab->width += (int)ad;
+	    slack = ad - floor(ad);
 	}
     }
 }
@@ -539,8 +528,13 @@ static void NotebookDoLayout(void *recordPtr)
     Ttk_PlaceLayout(nb->core.layout, nb->core.state, Ttk_WinBox(nbwin));
 
     /* Place tabs:
+     * Note: TabrowSize() takes into account -mintabwidth, but the tabs will
+     * actually have this minimum size when displayed only if there is enough
+     * space to draw the tabs with this width. Otherwise some of the tabs can
+     * be squeezed to a size smaller than -mintabwidth because we prefer
+     * displaying all tabs than than honoring -mintabwidth for all of them.
      */
-    TabrowSize(nb, nbstyle.tabOrient, &tabrowWidth, &tabrowHeight);
+    TabrowSize(nb, nbstyle.tabOrient, nbstyle.minTabWidth, &tabrowWidth, &tabrowHeight);
     tabrowBox = Ttk_PadBox(
 		    Ttk_PositionBox(&cavity,
 			tabrowWidth + Ttk_PaddingWidth(nbstyle.tabMargins),
@@ -548,7 +542,7 @@ static void NotebookDoLayout(void *recordPtr)
 			nbstyle.tabPosition),
 		    nbstyle.tabMargins);
 
-    SqueezeTabs(nb, tabrowWidth, tabrowBox.width, nbstyle.minTabWidth);
+    SqueezeTabs(nb, tabrowWidth, tabrowBox.width);
     PlaceTabs(nb, tabrowBox, nbstyle.tabPlacement);
 
     /* Layout for client area frame: