[#75] Field selection logic simplified.

Lib/src/com/yarcat/chemistrylines/view/SelectionInView.java

@@ -1,5 +1,7 @@
 package com.yarcat.chemistrylines.view;
 
+import android.annotation.SuppressLint;
+
 public class SelectionInView {
     public interface SelectionListener {
 
@@ -17,7 +19,9 @@ public interface SelectionListener {
 
     public void select(int n) {
         if (hasSource()) {
-            if (getSource() != n) {
+            if (getSource() == n) {
+                clear();
+            } else {
                 selectTarget(n);
             }
         } else {
@@ -26,25 +30,39 @@ public void select(int n) {
     }
 
     private void selectSource(int n) {
-        if (mListener != null && hasSource()) {
-            mListener.onSourceCleared(mSelection[0]);
-        }
+        clearSource();
         mSelection[0] = n;
         if (mListener != null && hasSource()) {
             mListener.onNewSource(n);
         }
     }
 
     private void selectTarget(int n) {
-        if (mListener != null && hasTarget()) {
-            mListener.onTargetCleared(mSelection[1]);
-        }
+        clearTarget();
         mSelection[1] = n;
         if (mListener != null && hasTarget()) {
             mListener.onNewTarget(n);
         }
     }
 
+    private void clearSource() {
+        if (hasSource()) {
+            if (mListener != null) {
+                mListener.onSourceCleared(mSelection[0]);
+            }
+            mSelection[0] = -1;
+        }
+    }
+
+    private void clearTarget() {
+        if (hasTarget()) {
+            if (mListener != null) {
+                mListener.onTargetCleared(mSelection[1]);
+            }
+            mSelection[1] = -1;
+        }
+    }
+
     public void clear() {
         if (mListener != null) {
             if (hasSource()) {
@@ -76,4 +94,11 @@ public int getTarget() {
     public void setListener(SelectionListener l) {
         mListener = l;
     }
+
+    @SuppressLint("DefaultLocale")
+    @Override
+    public String toString() {
+        return String
+            .format("Selection(%d,  %d)", mSelection[0], mSelection[1]);
+    }
 }

Lib/tests/com/yarcat/tests/chemistrylines/SelectionInViewTest.java

@@ -0,0 +1,78 @@
+package com.yarcat.tests.chemistrylines;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import com.yarcat.chemistrylines.view.SelectionInView;
+
+public class SelectionInViewTest {
+
+    SelectionInView s;
+
+    @Before
+    public void setUp() {
+        s = new SelectionInView();
+    }
+
+    @Test
+    public void empty() {
+        assertFalse(s.hasSource());
+        assertFalse(s.hasTarget());
+    }
+
+    @Test
+    public void oneSelect() {
+        s.select(1);
+        assertTrue(s.hasSource());
+        assertFalse(s.hasTarget());
+    }
+
+    @Test
+    public void differentCells() {
+        s.select(1);
+        s.select(2);
+        assertTrue(s.hasSource());
+        assertTrue(s.hasTarget());
+        assertEquals(1, s.getSource());
+        assertEquals(2, s.getTarget());
+        s.select(3);
+        assertTrue(s.hasSource());
+        assertTrue(s.hasTarget());
+        assertEquals(1, s.getSource());
+        assertEquals(3, s.getTarget());
+    }
+
+    @Test
+    public void reselectSource() {
+        s.select(1);
+        assertTrue(s.hasSource());
+        assertFalse(s.hasTarget());
+        s.select(1);
+        assertFalse(s.hasSource());
+        assertFalse(s.hasTarget());
+        s.select(1);
+        s.select(2);
+        assertTrue(s.hasSource());
+        assertTrue(s.hasTarget());
+        s.select(1);
+        assertFalse(s.hasSource());
+        assertFalse(s.hasTarget());
+    }
+
+    @Test
+    public void clear() {
+        s.select(1);
+        s.clear();
+        assertFalse(s.hasSource());
+        assertFalse(s.hasTarget());
+        s.select(1);
+        s.select(2);
+        s.clear();
+        assertFalse(s.hasSource());
+        assertFalse(s.hasTarget());
+    }
+}

Swing/src/com/yarcat/chemistrylines/swing/SwingChemistryLines.java

@@ -65,40 +65,42 @@ public void mouseExited(MouseEvent e) {
 
     @Override
     public void mousePressed(MouseEvent e) {
-        FieldButton b = (FieldButton) e.getSource();
-        if (selection().hasSource() && selection().hasTarget()
-            && selection().getSource() == selection().getTarget()
-            && selection().getSource() == b.n) {
-            selection().clear();
+        final FieldButton b = (FieldButton) e.getSource();
+        if (selection().hasSource()) {
+            selection().select(b.n);
+            tryMakeMove();
         } else {
-            tryMakeMove(b.n);
+            selection().select(b.n);
         }
+        // TODO: refresh field via selection listener
         refreshField();
     }
 
-    private void tryMakeMove(int id) {
-        // We need this because for the drag case mouseReleased is called for
-        // the source button, and we don't wanna overwrite the value.
-        if (!selection().hasTarget()) {
-            selection().select(id);
+    @Override
+    public void mouseReleased(MouseEvent e) {
+        if (selection().hasSource()) {
+            // mouseReleased() gets the same button that was pressed.
+            tryMakeMove();
         }
-        if (selection().hasTarget()
-            && selection().getSource() != selection().getTarget()) {
+    }
+
+    private void tryMakeMove() {
+        if (selection().hasTarget()) {
+            int s, t;
+            if (mGame.getField().at(selection().getSource()).isEmpty()) {
+                s = selection().getTarget();
+                t = selection().getSource();
+            } else {
+                s = selection().getSource();
+                t = selection().getTarget();
+            }
             try {
-                mGame.makeMove(selection().getSource(), selection()
-                    .getTarget());
+                mGame.makeMove(s, t);
                 refresh();
             } catch (InvalidMove e1) {
             }
             selection().clear();
-        }
-    }
-
-    @Override
-    public void mouseReleased(MouseEvent e) {
-        if (selection().hasSource()) {
-            FieldButton b = (FieldButton) e.getSource();
-            tryMakeMove(b.n);
+            refreshField();
         }
     }