feed the automation settings into the movers

src/main/java/wtf/beatrice/autosqueal/util/RunnerUtil.java

@@ -1,5 +1,7 @@
 package wtf.beatrice.autosqueal.util;
 
+import wtf.beatrice.autosqueal.config.ScreenArea;
+
 import java.awt.*;
 
 public class RunnerUtil {
@@ -8,9 +10,35 @@ public class RunnerUtil {
         throw new AssertionError("The RunnerUtil class is not intended to be instantiated.");
     }
 
-    public static final int SECONDS_BETWEEN_MOVES = 10;
-
     public static final int SCREEN_HEIGHT = Toolkit.getDefaultToolkit().getScreenSize().height;
     public static final int SCREEN_WIDTH = Toolkit.getDefaultToolkit().getScreenSize().width;
 
+    /**
+     * The bounds of the screens the cursor may travel to, according to the
+     * given setting. Fetched on every call, so that a change of setting, or
+     * a screen plugged in while the app runs, is picked up by the next
+     * movement.
+     *
+     * The result is never empty: when no screen is found, the main screen
+     * is returned, because it always exists.
+     */
+    public static Rectangle screenBounds(ScreenArea area) {
+        Rectangle bounds = new Rectangle();
+
+        if (area == ScreenArea.ALL) {
+            for (GraphicsDevice device : GraphicsEnvironment.getLocalGraphicsEnvironment().getScreenDevices()) {
+                bounds.add(device.getDefaultConfiguration().getBounds());
+            }
+        }
+
+        if (bounds.isEmpty()) {
+            // the main screen was requested, or no other screen was found
+            bounds = GraphicsEnvironment.getLocalGraphicsEnvironment()
+                    .getDefaultScreenDevice().getDefaultConfiguration().getBounds();
+        }
+
+        // defensive copy: the callers treat the rectangle as theirs
+        return new Rectangle(bounds);
+    }
+
 }