fix steps

app/src/main/java/gui/menu/SudokuView.java

@@ -1,5 +1,7 @@
 package gui.menu;
 
+import java.util.ArrayList;
+import java.util.List;
 import java.util.concurrent.CancellationException;
 
 import gui.widget.SudokuRenderer;
@@ -11,6 +13,7 @@ import sudoku.solver.HintHelper;
 import sudoku.solver.HumanSolver;
 import sudoku.solver.MixedSolver;
 import sudoku.solver.Solver;
+import sudoku.solver.SolverStep;
 import sudoku.solver.HintHelper.Hint;
 import sudoku.structure.MultiDoku;
 
@@ -90,8 +93,9 @@ public class SudokuView extends BaseView {
 
 	private void startSolve(Solver solver) {
 		resolveThread = new Thread(() -> {
+			List<SolverStep> steps = new ArrayList<>();
 			try {
-				unresolved = !solver.solve(this.doku);
+				unresolved = !solver.solve(this.doku, steps);
 			} catch (CancellationException e) {
 				System.out.println("The user is bored !");
 			}

app/src/main/java/sudoku/solver/BacktrackingSolver.java

@@ -36,7 +36,7 @@ public class BacktrackingSolver implements Solver {
 		for (int symbol : possibleSymbols) {
 			cellToFill.setSymbolIndex(symbol);
 			addStep(cellToFill, steps);
-			if (this.solve(doku)) {
+			if (this.solve(doku, steps)) {
 				return true;
 			} else {
 				cellToFill.setSymbolIndex(Cell.NOSYMBOL);

app/src/main/java/sudoku/solver/HumanSolver.java

@@ -49,7 +49,7 @@ public class HumanSolver implements Solver {
 			cellToFill.setSymbolIndex(possibleSymbols.getFirst());
 			addStep(cellToFill, steps);
 
-			return this.solve(doku);
+			return this.solve(doku, steps);
 		}
 
 		return doku.isSolved();

app/src/main/java/sudoku/solver/MixedSolver.java

@@ -50,7 +50,7 @@ public class MixedSolver implements Solver {
         if (possibleSymbols.size() == 1) {
             cellToFill.setSymbolIndex(possibleSymbols.getFirst());
             addStep(cellToFill, steps);
-            if (this.solve(doku)) {
+            if (this.solve(doku, steps)) {
                 return true;
             }
         }
@@ -61,7 +61,7 @@ public class MixedSolver implements Solver {
 
             cellToFill.setSymbolIndex(nextSymbol);
             addStep(cellToFill, steps);
-            if (this.solve(doku)) {
+            if (this.solve(doku, steps)) {
                 return true;
             }
             cellToFill.setSymbolIndex(Cell.NOSYMBOL);

app/src/main/java/sudoku/solver/RandomSolver.java

@@ -52,7 +52,7 @@ public class RandomSolver implements Solver {
 
             cellToFill.setSymbolIndex(nextSymbol);
             addStep(cellToFill, steps);
-            if (this.solve(doku)) {
+            if (this.solve(doku, steps)) {
                 return true;
             }
             cellToFill.setSymbolIndex(Cell.NOSYMBOL);