Improve layout, require grids to be square

.idea/vcs.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="VcsDirectoryMappings">
-    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+    <mapping directory="" vcs="Git" />
   </component>
 </project>
\ No newline at end of file

app/src/main/java/edu/liu/floodgame/FloodGrid.java

 package edu.liu.floodgame;
 
 public interface FloodGrid {
-    int numRows();
-    int numColumns();
-    int numCells(); // Should always be NUM_ROWS*columns
+    int edgeSize();
+    int numCells(); // Should always be edgeSize squared
 
     int getColorAt(int row, int column);
     int getColorAt(int index);

app/src/main/java/edu/liu/floodgame/FloodGridArray2D.java

@@ -4,27 +4,22 @@ public class FloodGridArray2D implements FloodGrid {
 
     private int[][] grid;
 
-    FloodGridArray2D(int numRows, int numColumns) {
-        if(numRows * numColumns < 3) {
-            throw new IllegalArgumentException("numRows*numColumns too small");
+    FloodGridArray2D(int edgeSize) {
+        if(edgeSize < 2) {
+            throw new IllegalArgumentException("edgeSize too small");
         }
-        assert numRows > 0;
-        grid = new int[numRows][numColumns];
+        grid = new int[edgeSize][edgeSize];
     }
 
     @Override
-    public int numRows() {
+    public int edgeSize() {
         return grid.length;
     }
 
-    @Override
-    public int numColumns() {
-        return grid[0].length;
-    }
-
     @Override
     public int numCells() {
-        return numRows() * numColumns();
+
+        return grid.length * grid.length;
     }
 
     @Override
@@ -34,7 +29,7 @@ public class FloodGridArray2D implements FloodGrid {
 
     @Override
     public int getColorAt(int index) {
-        return getColorAt(index / numColumns(), index % numColumns());
+        return getColorAt(index / edgeSize(), index % edgeSize());
     }
 
     @Override
@@ -44,6 +39,6 @@ public class FloodGridArray2D implements FloodGrid {
 
     @Override
     public void setColorAt(int index, int color) {
-        setColorAt(index / numColumns(), index % numColumns(), color);
+        setColorAt(index / edgeSize(), index % edgeSize(), color);
     }
 }

app/src/main/java/edu/liu/floodgame/FloodGridOps.java

@@ -18,8 +18,8 @@ public class FloodGridOps {
 
     static String toString(FloodGrid grid) {
         StringBuilder buf = new StringBuilder();
-        for(int row = 0; row < grid.numRows(); row++) {
-            for(int col = 0; col < grid.numColumns(); col++) {
+        for(int row = 0; row < grid.edgeSize(); row++) {
+            for(int col = 0; col < grid.edgeSize(); col++) {
                 buf.append(grid.getColorAt(row, col));
             }
             buf.append('\n');
@@ -59,9 +59,9 @@ public class FloodGridOps {
             int color)
     {
         return (row >= 0
-                && row < grid.numRows()
+                && row < grid.edgeSize()
                 && column >= 0
-                && column < grid.numColumns()
+                && column < grid.edgeSize()
                 && !alreadyVisited[row][column]
                 && grid.getColorAt(row, column) == color);
     }
@@ -95,14 +95,15 @@ public class FloodGridOps {
     }
 
     static void flood(FloodGrid grid, int newColor) {
-        flood(grid, new boolean[grid.numRows()][grid.numColumns()], 0, 0,
-                grid.getColorAt(0,0), newColor);
+        boolean[][] alreadyVisited = new boolean[grid.edgeSize()][grid.edgeSize()];
+        int previousColor = grid.getColorAt(0,0);
+        flood(grid, alreadyVisited, 0, 0, previousColor, newColor);
     }
 
     // Console version of the game!
     public static void main(String[] args) throws IOException {
         final int numColors = 4;
-        FloodGrid grid = new FloodGridArray2D(5, 7);
+        FloodGrid grid = new FloodGridArray2D(6);
         randomize(grid, new Random(), numColors);
         BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
         System.out.print(toString(grid));

app/src/main/java/edu/liu/floodgame/GridActivity.java

@@ -46,7 +46,7 @@ public class GridActivity extends AppCompatActivity implements FloodGrid {
         final int NUM_CELLS = NUM_ROWS * NUM_COLUMNS;
         gridLayout.setColumnCount(NUM_COLUMNS);
         for(int i = 0; i < NUM_CELLS; i++) {
-            gridLayout.addView(new GridCellView(this, 100));
+            gridLayout.addView(new GridCellView(this));
         }
         if(savedInstanceState == null) {
             System.out.println("New random grid");
@@ -64,12 +64,7 @@ public class GridActivity extends AppCompatActivity implements FloodGrid {
     }
 
     @Override
-    public int numRows() {
-        return numCells() / numColumns();
-    }
-
-    @Override
-    public int numColumns() {
+    public int edgeSize() {
         return gridLayout.getColumnCount();
     }
 
@@ -80,7 +75,7 @@ public class GridActivity extends AppCompatActivity implements FloodGrid {
 
     @Override
     public int getColorAt(int row, int column) {
-        return getColorAt(row * numColumns() + column);
+        return getColorAt(row * edgeSize() + column);
     }
 
     @Override
@@ -91,7 +86,7 @@ public class GridActivity extends AppCompatActivity implements FloodGrid {
 
     @Override
     public void setColorAt(int row, int column, int color) {
-        setColorAt(row * numColumns() + column, color);
+        setColorAt(row * edgeSize() + column, color);
     }
 
     @Override

app/src/main/java/edu/liu/floodgame/GridCellView.java

 package edu.liu.floodgame;
 
-import android.content.Context;
 import android.support.v7.widget.GridLayout;
 import android.view.View;
 
@@ -8,10 +7,11 @@ public class GridCellView extends View {
 
     int color;
 
-    GridCellView(GridActivity activity, int size) {
+    GridCellView(GridActivity activity) {
         super(activity);
         GridLayout.LayoutParams lp = new GridLayout.LayoutParams();
-        lp.width = lp.height = size;
+        lp.rowSpec = lp.columnSpec = GridLayout.spec(GridLayout.UNDEFINED, 1f);
+        lp.width = lp.height = 0;
         setLayoutParams(lp);
     }
 

app/src/main/res/layout/activity_flood_grid.xml

@@ -7,37 +7,49 @@
 
     <android.support.v7.widget.GridLayout
         android:id="@+id/grid"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
+        android:layout_width="0dp"
+        android:layout_height="0dp"
+        android:padding="10dp"
         app:columnCount="2"
         app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintDimensionRatio="1"
         app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintHorizontal_bias="0.498"
         app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toTopOf="parent">
+        app:layout_constraintTop_toTopOf="parent"
+        app:layout_constraintVertical_bias="0.0">
 
         <View
             android:id="@+id/sample1"
-            android:layout_width="50dp"
-            android:layout_height="50dp"
-            android:background="@color/colorPrimary" />
+            android:layout_width="0dp"
+            android:layout_height="0dp"
+            android:background="@color/colorPrimary"
+            app:layout_columnWeight="1"
+            app:layout_rowWeight="1" />
 
         <View
             android:id="@+id/sample2"
-            android:layout_width="50dp"
-            android:layout_height="50dp"
-            android:background="@color/colorAccent" />
+            android:layout_width="0dp"
+            android:layout_height="0dp"
+            android:background="@color/colorAccent"
+            app:layout_columnWeight="1"
+            app:layout_rowWeight="1" />
 
         <View
             android:id="@+id/sample3"
-            android:layout_width="50dp"
-            android:layout_height="50dp"
-            android:background="@color/colorPrimaryDark" />
+            android:layout_width="0dp"
+            android:layout_height="0dp"
+            android:background="@color/colorPrimaryDark"
+            app:layout_columnWeight="1"
+            app:layout_rowWeight="1" />
 
         <View
             android:id="@+id/sample4"
-            android:layout_width="50dp"
-            android:layout_height="50dp"
-            android:background="@color/colorPrimary" />
+            android:layout_width="0dp"
+            android:layout_height="0dp"
+            android:background="@color/colorPrimary"
+            app:layout_columnWeight="1"
+            app:layout_rowWeight="1" />
     </android.support.v7.widget.GridLayout>
 
     <LinearLayout