[gnome-sudoku/vala-port] Show 'Clear' button in popover for a filled cell

[Parin Porecha <parinporecha src gnome org>]

commit 15ec227748a0c3671f1f2660aec00fe283ab2c1a
Author: Parin Porecha <parinporecha gmail com>
Date:   Sat May 24 12:51:59 2014 +0530

    Show 'Clear' button in popover for a filled cell

 src/number-picker.vala |   37 +++++++++++++++++++++----------------
 src/sudoku-view.vala   |    7 ++++++-
 2 files changed, 27 insertions(+), 17 deletions(-)
---
diff --git a/src/number-picker.vala b/src/number-picker.vala
index 94e29ea..c39417e 100644
--- a/src/number-picker.vala
+++ b/src/number-picker.vala
@@ -6,7 +6,9 @@ private class NumberPicker : Gtk.Grid
 
     public signal void number_picked (int number);
 
-    public NumberPicker (ref SudokuBoard board, bool show_clear = true) {
+    private Gtk.Button clear_button;
+
+    public NumberPicker (ref SudokuBoard board) {
         this.board = board;
 
         for (var col = 0; col < board.block_cols; col++)
@@ -35,24 +37,27 @@ private class NumberPicker : Gtk.Grid
             }
         }
 
-        if (show_clear)
-        {
-            var button = new Gtk.Button ();
-            button.focus_on_click = false;
-            this.attach (button, 0, 4, 3, 1);
-
-            var label = new Gtk.Label ("<big>Clear</big>");
-            label.use_markup = true;
-            button.add (label);
-            label.show ();
+        clear_button = new Gtk.Button ();
+        clear_button.focus_on_click = false;
+        this.attach (clear_button, 0, 4, 3, 1);
 
-            button.clicked.connect (() => {
-                number_picked(0);
-            });
+        var label = new Gtk.Label ("<big>Clear</big>");
+        label.use_markup = true;
+        clear_button.add (label);
+        label.show ();
 
-            button.show ();
-        }
+        clear_button.clicked.connect (() => {
+            number_picked(0);
+        });
 
         this.show ();
     }
+
+    public void set_clear_button_visibility (bool visible)
+    {
+        if (visible)
+            clear_button.show ();
+        else
+            clear_button.hide ();
+    }
 }
diff --git a/src/sudoku-view.vala b/src/sudoku-view.vala
index 3f2b7de..27cf25b 100644
--- a/src/sudoku-view.vala
+++ b/src/sudoku-view.vala
@@ -124,13 +124,15 @@ private class SudokuCellView : Gtk.DrawingArea
         }
     }
 
+    private NumberPicker number_picker;
+
     public SudokuCellView (int row, int col, ref SudokuGame game, bool small = false)
     {
         this.game = game;
         this._row = row;
         this._col = col;
 
-        var number_picker = new NumberPicker(ref game.board, value != 0);
+        number_picker = new NumberPicker(ref game.board);
         number_picker.number_picked.connect ((o, number) => {
             value = number;
             if (number == 0)
@@ -215,7 +217,10 @@ private class SudokuCellView : Gtk.DrawingArea
     private void show_number_picker ()
     {
         if (!is_fixed)
+        {
+            number_picker.set_clear_button_visibility (value != 0);
             popover.show ();
+        }
     }
 
     private void show_note_editor (int top)