Ticket #2199: Buttonbar mouseclicks are off

Case 1: Make the terminal window 85 characters wide. Click (with the
mouse) on the right side of the "Copy" button on the bottom. See the
Move dialog appearing instead of the Copy dialog.

Case 2: Make the terminal 42 characters wide. Click on the bottom right
corner (the Re~ov button). MC invokes its menu or quits, depending on
the exact click location.

The patch that solves all these. The extra space is not assigned to the
first buttons, but distributed mostly evenly across buttons,
guaranteeing that the first five get exactly as much (or one character
less) than the second five, just as it works for the panels. Also, mouse
clicks use the exact same boundaries that were used when printing the
buttons.

Signed-off-by: Yury V. Zaytsev <yury@shurup.com>

Minor code cleanup, renamed local variable to avoid shadowing of global
variable, fixed formatting.

Signed-off-by: Slava Zanko <slavazanko@gmail.com>
Signed-off-by: Andrew Borodin <aborodin@vmail.ru>

src/widget.c

@@ -3017,12 +3017,72 @@ buttonbar_call (WButtonBar * bb, int i)
     return ret;
 }
 
-/* calculate width of one button, width is never lesser than 7 */
-static int
-buttonbat_get_button_width (void)
+/* calculate positions of buttons; width is never less than 7 */
+static void
+buttonbar_init_button_positions (WButtonBar *bb)
 {
-    int result = COLS / BUTTONBAR_LABELS_NUM;
-    return (result >= 7) ? result : 7;
+    int i;
+    int pos = 0;
+
+    if (COLS < BUTTONBAR_LABELS_NUM * 7)
+    {
+        for (i = 0; i < BUTTONBAR_LABELS_NUM; i++)
+        {
+            if (pos + 7 <= COLS)
+                pos += 7;
+
+            bb->labels[i].end_coord = pos;
+        }
+    }
+    else
+    {
+        /* Distribute the extra width in a way that the middle vertical line
+           (between F5 and F6) aligns with the two panels. The extra width
+           is distributed in this order: F10, F5, F9, F4, ..., F6, F1. */
+        int lc_div, mod;
+
+        lc_div = COLS / BUTTONBAR_LABELS_NUM;
+        mod = COLS % BUTTONBAR_LABELS_NUM;
+
+        for (i = 0; i < BUTTONBAR_LABELS_NUM / 2; i++)
+        {
+            pos += lc_div;
+            if (BUTTONBAR_LABELS_NUM / 2 - 1 - i < mod / 2)
+                pos++;
+
+            bb->labels[i].end_coord = pos;
+        }
+
+        for (; i < BUTTONBAR_LABELS_NUM; i++)
+        {
+            pos += lc_div;
+            if (BUTTONBAR_LABELS_NUM - 1 - i < (mod + 1) / 2)
+                pos++;
+
+            bb->labels[i].end_coord = pos;
+        }
+    }
+}
+
+/* return width of one button */
+static int
+buttonbar_get_button_width (const WButtonBar *bb, int i)
+{
+    if (i == 0)
+        return bb->labels[0].end_coord;
+    return bb->labels[i].end_coord - bb->labels[i - 1].end_coord;
+}
+
+static int
+buttonbar_get_button_by_x_coord (const WButtonBar *bb, int x)
+{
+    int i;
+
+    for (i = 0; i < BUTTONBAR_LABELS_NUM; i++)
+        if (bb->labels[i].end_coord > x)
+            return i;
+
+    return (-1);
 }
 
 static cb_ret_t
@@ -3046,29 +3106,25 @@ buttonbar_callback (Widget * w, widget_msg_t msg, int parm)
     case WIDGET_DRAW:
         if (bb->visible)
         {
-            int offset = 0;
-            int count_free_positions;
-
+            buttonbar_init_button_positions (bb);
             widget_move (&bb->widget, 0, 0);
             tty_setcolor (DEFAULT_COLOR);
-            bb->btn_width = buttonbat_get_button_width ();
             tty_printf ("%-*s", bb->widget.cols, "");
-            count_free_positions = COLS - bb->btn_width * BUTTONBAR_LABELS_NUM;
+            widget_move (&bb->widget, 0, 0);
 
-            for (i = 0; i < COLS / bb->btn_width && i < BUTTONBAR_LABELS_NUM; i++)
+            for (i = 0; i < BUTTONBAR_LABELS_NUM; i++)
             {
-                widget_move (&bb->widget, 0, (i * bb->btn_width) + offset);
+                int width;
+
+                width = buttonbar_get_button_width (bb, i);
+                if (width <= 0)
+                    break;
+
                 tty_setcolor (BUTTONBAR_HOTKEY_COLOR);
                 tty_printf ("%2d", i + 1);
                 tty_setcolor (BUTTONBAR_BUTTON_COLOR);
                 text = (bb->labels[i].text != NULL) ? bb->labels[i].text : "";
-                tty_print_string (str_fit_to_term (text,
-                                                   bb->btn_width - 2 + (int) (offset <
-                                                                              count_free_positions),
-                                                   J_LEFT_FIT));
-
-                if (count_free_positions != 0 && offset < count_free_positions)
-                    offset++;
+                tty_print_string (str_fit_to_term (text, width - 2, J_LEFT_FIT));
             }
         }
         return MSG_HANDLED;
@@ -3093,8 +3149,8 @@ buttonbar_event (Gpm_Event * event, void *data)
         return MOU_NORMAL;
     if (event->y == 2)
         return MOU_NORMAL;
-    button = (event->x - 1) * BUTTONBAR_LABELS_NUM / COLS;
-    if (button < BUTTONBAR_LABELS_NUM)
+    button = buttonbar_get_button_by_x_coord (bb, event->x - 1);
+    if (button >= 0)
         buttonbar_call (bb, button);
     return MOU_NORMAL;
 }
@@ -3111,7 +3167,6 @@ buttonbar_new (gboolean visible)
     bb->visible = visible;
     widget_want_hotkey (bb->widget, 1);
     widget_want_cursor (bb->widget, 0);
-    bb->btn_width = buttonbat_get_button_width ();
 
     return bb;
 }

src/widget.h

@@ -173,11 +173,11 @@ struct WListbox {
 typedef struct WButtonBar {
     Widget widget;
     gboolean visible;		/* Is it visible? */
-    int btn_width;		/* width of one button */
     struct {
 	char *text;
 	unsigned long command;
 	Widget *receiver;
+	int end_coord;		/* cumulative width of buttons so far */
     } labels [BUTTONBAR_LABELS_NUM];
 } WButtonBar;