[gnome-sudoku] Place numbers in number picker as on numpad

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 3db33eb2d81dd674fe2fdb8205f0ce48e79ae9f4
Author: shak-mar <shakmar openmailbox org>
Date:   Wed Jul 10 21:49:08 2019 +0200

    Place numbers in number picker as on numpad
    
    Now that it's common to open a number picker and then press a number on
    the numpad, it's very annoying that the placement of the numbers don't
    correspond properly:  This makes it easy to get confused, because you
    look at the number to press on the number picker, but you need to press
    a key that is located differently on your keyboard.

 src/number-picker.vala | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)
---
diff --git a/src/number-picker.vala b/src/number-picker.vala
index 481c0c9..6ab46f0 100644
--- a/src/number-picker.vala
+++ b/src/number-picker.vala
@@ -42,7 +42,7 @@ private class NumberPicker : Gtk.Grid
         {
             for (var row = 0; row < board.block_rows; row++)
             {
-                int n = col + row * board.block_cols + 1;
+                int n = col + (2 - row) * board.block_cols + 1;
 
                 var button = earmark ? new ToggleButton () : new Button ();
                 button.focus_on_click = false;
@@ -124,8 +124,7 @@ private class NumberPicker : Gtk.Grid
     {
         if (state && earmarks_active >= EARMARKS_MAX_ALLOWED)
             return false;
-        var button = (ToggleButton) this.get_child_at (index % board.block_cols, index / board.block_rows);
-        button.set_active (state);
+        get_button_for(index).set_active (state);
         return true;
     }
 
@@ -133,13 +132,19 @@ private class NumberPicker : Gtk.Grid
     {
         if (state)
             for (var i = 0; i < board.max_val; i++)
-                this.get_child_at (i % board.block_cols, i / board.block_rows).sensitive = true;
+                get_button_for(i).sensitive = true;
         else
             for (var i = 0; i < board.max_val; i++)
             {
-                var button = (ToggleButton) this.get_child_at (i % board.block_cols, i / board.block_rows);
+                var button = get_button_for (i);
                 if (!button.active)
                     button.sensitive = false;
             }
     }
+
+    private ToggleButton get_button_for (int number)
+    {
+        return (ToggleButton) this.get_child_at(number % board.block_cols,
+            2 - (number / board.block_rows));
+    }
 }