basic board implementation, connected to file inputs from user. additionally expanded available settings and created structure for theming.

src/gui/Board.java

@@ -1,8 +1,10 @@
 package gui;
 
 import java.awt.GridLayout;
+import java.awt.LayoutManager;
 
 import javax.swing.JPanel;
+import javax.swing.JLabel;
 
 import gui.backend.Settings;
 
@@ -20,6 +22,7 @@ import gui.backend.Settings;
 public class Board extends JPanel {
     private Settings s;
     private Cell[][] grid;
+    private Cell selected;
 
     /**
      * Create a new Board object with the default styling from settings.
@@ -31,6 +34,31 @@ public class Board extends JPanel {
         this.s = s;
         this.grid = grid;
         style();
+        createBoard();
+    }
+
+    /**
+     * Get the grid of the Board.
+     * 
+     * @return
+     */
+    public Cell[][] getGrid() {
+        return grid;
+    }
+
+    /**
+     * Set the grid of the Board to the given grid.
+     * 
+     * Intended to be used when loading a new puzzle.
+     * 
+     * @param grid
+     */
+    public void setGrid(Cell[][] grid) {
+        this.grid = grid;
+        removeAll();
+        createBoard();
+        repaint();
+        revalidate();
     }
 
     /**
@@ -41,6 +69,139 @@ public class Board extends JPanel {
     }
 
     private void createBoard() {
-        // TODO: Create the board with the given grid.
+        for(int i = 0; i < 9; i++) {
+            for(int j = 0; j < 9; j++) {
+                CellGUI cell = new CellGUI(grid[i][j], s.getCellGUIStartMode());
+                add(cell);
+            }
+        }
     }
-}
+
+    /**
+     * GUI representation of a single cell in the Sudoku grid.
+     */
+    private class CellGUI extends JPanel {
+        private static GridLayout noteLayout = new GridLayout(3, 3);
+        private static GridLayout valueLayout = new GridLayout(1, 1);
+
+        private Cell cell;
+        private JLabel valueLabel;
+        private JLabel[] notesLabels;
+        private boolean notes; // true for notes, false for value
+        private boolean startInNotesOrValueMode;
+
+        /**
+         * Create a new CellGUI object with the given single cell.
+         * 
+         * Start blank cells in notes mode if startInNotesOrValueMode is true.
+         * 
+         * @param cell
+         * @param startInNotesOrValueMode
+         */
+        public CellGUI(Cell cell, boolean startInNotesOrValueMode) {
+            super();
+            this.cell = cell;
+            this.startInNotesOrValueMode = startInNotesOrValueMode;
+
+            // Populate the cell with the appropriate value or notes.
+            if(cell.getValue() == 0) {
+                generateNotes();
+                
+                if(startInNotesOrValueMode) {
+                    setLayout(noteLayout);
+                    notes = true;
+                } else {
+                    setLayout(valueLayout);
+                    notes = false;
+                    valueLabel = new JLabel("");
+                    add(valueLabel);
+                }
+            } else {
+                valueLabel = new JLabel(Integer.toString(cell.getValue()));
+                add(valueLabel);
+            }
+        }
+
+        /**
+         * Get the value of the underlying Cell object.
+         * 
+         * @return int
+         */
+        public int getValue() {
+            return cell.getValue();
+        }
+
+        /**
+         * Add a possible value to the cell.
+         * 
+         * @param value
+         */
+        public void addPossibleValue(int value) {
+            cell.addPossibleValue(value);
+        }
+
+        /**
+         * Remove a possible value from the cell.
+         * 
+         * @return
+         */
+        public void removePossibleValue(int value) {
+            cell.removePossibleValue(value);
+        }
+
+        /**
+         * Get the possible values of the underlying Cell object.
+         * 
+         * @return int[]
+         */
+        public int[] getPossibleValues() {
+            return cell.getPossibleValues();
+        }
+
+        /**
+         * Toggle the mode of the cell between value and note, including the
+         * layout of the cell.
+         */
+        public void setNoteMode() {
+            if(notes) {
+                removeAll();
+                setLayout(valueLayout);
+                repaint();
+                revalidate();
+
+                add(valueLabel);
+            } else {
+                removeAll();
+                setLayout(noteLayout);
+                repaint();
+                revalidate();
+
+                generateNotes();
+            }
+            
+            notes = !notes;
+        }
+
+        /**
+         * Create the GUI components for the cell.
+         */
+        private void generateNotes() {
+            if(cell.getPossibleValues().length == 0) {
+                notesLabels = new JLabel[9];
+                return;
+            }
+
+            // Add the noted possible values to the cell.
+            int index = 0;
+            for(int i = 1; i <= 9; i++) {
+                if(cell.getPossibleValues()[index] == i) {
+                    notesLabels[index] = new JLabel(Integer.toString(i));
+                    index++;
+                } else {
+                    notesLabels[index] = new JLabel("");
+                }
+                add(notesLabels[index]);
+            }
+        }
+    }
+}