Add methods to save and restore main window state

enigma-swing/src/main/java/cuchaz/enigma/gui/elements/MainWindow.java

@@ -1,11 +1,12 @@
 package cuchaz.enigma.gui.elements;
 
-import java.awt.BorderLayout;
-import java.awt.Container;
+import java.awt.*;
+import java.util.OptionalInt;
 
 import javax.swing.JFrame;
 import javax.swing.JMenuBar;
 
+import cuchaz.enigma.config.ConfigSection;
 import cuchaz.enigma.gui.elements.rpanel.WorkspaceRPanelContainer;
 
 public class MainWindow {
@@ -21,14 +22,54 @@ public MainWindow(String title) {
 
 		Container contentPane = this.frame.getContentPane();
 		contentPane.setLayout(new BorderLayout());
-		contentPane.add(workspace.getUi(), BorderLayout.CENTER);
+		contentPane.add(this.workspace.getUi(), BorderLayout.CENTER);
 		contentPane.add(this.statusBar.getUi(), BorderLayout.SOUTH);
 	}
 
 	public void setVisible(boolean visible) {
 		this.frame.setVisible(visible);
 	}
 
+	/**
+	 * Saves the state (window geometry and RPanel positions) of this main
+	 * window.
+	 *
+	 * @param section the configuration section to write to
+	 */
+	public void saveState(ConfigSection section) {
+		Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
+		Point location = this.frame.getLocationOnScreen();
+		Dimension dim = this.frame.getSize();
+
+		section.setInt("X %s".formatted(screenSize.width), location.x);
+		section.setInt("Y %d".formatted(screenSize.height), location.y);
+		section.setInt("Width %d".formatted(screenSize.width), dim.width);
+		section.setInt("Height %d".formatted(screenSize.height), dim.height);
+	}
+
+	public void restoreState(ConfigSection section) {
+		Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
+
+		OptionalInt width = section.getInt("Width %d".formatted(screenSize.width));
+		OptionalInt height = section.getInt("Height %d".formatted(screenSize.height));
+		OptionalInt x = section.getInt("X %d".formatted(screenSize.width));
+		OptionalInt y = section.getInt("Y %d".formatted(screenSize.height));
+
+		if (width.isPresent() && height.isPresent()) {
+			this.frame.setSize(new Dimension(width.getAsInt(), height.getAsInt()));
+		}
+
+		if (x.isPresent() && y.isPresent()) {
+			int ix = x.getAsInt();
+			int iy = y.getAsInt();
+
+			// Ensure that the position is on the screen.
+			if (ix >= 0 && iy >= 0 && ix <= screenSize.width && iy <= screenSize.height) {
+				this.frame.setLocation(ix, iy);
+			}
+		}
+	}
+
 	public WorkspaceRPanelContainer workspace() {
 		return this.workspace;
 	}