Added save to PNG. Minor improvements.

multidraw-client/src/main/java/module-info.java

@@ -1,6 +1,9 @@
 module multidraw.client {
+    requires transitive java.desktop;
+
     requires javafx.graphics;
     requires javafx.controls;
+    requires javafx.swing;
     requires multidraw.shared;
 
     exports wit.pap.multidraw.client.gui to javafx.graphics;

multidraw-client/src/main/java/wit/pap/multidraw/client/gui/MultiDrawApplication.java

@@ -22,6 +22,7 @@
 import javafx.scene.paint.Color;
 import javafx.scene.shape.StrokeLineCap;
 import javafx.scene.shape.StrokeLineJoin;
+import javafx.stage.FileChooser;
 import javafx.stage.Modality;
 import javafx.stage.Stage;
 
@@ -37,28 +38,32 @@
 import wit.pap.multidraw.shared.globals.Globals;
 import wit.pap.multidraw.shared.LayeredImage;
 
+import java.io.File;
 import java.io.IOException;
 import java.net.InetAddress;
 import java.net.UnknownHostException;
 import java.util.function.UnaryOperator;
 import java.util.regex.Pattern;
 
 public class MultiDrawApplication extends Application {
-    Button btnAbout, btnSave, btnClear, btnConnectDisconnect;
-    HBox connectionForm;
-    TextField tfHost, tfHostPort, tfNickname, tfRoom;
-    Spinner<Integer> spnPenSize;
-    ColorPicker colorPicker;
-
-    LayeredImage layeredImage;
-    LayeredImageStack imageStack;
-    Canvas canvas;
-    ImageView bgImageView, mgImageView;
+    private Stage primaryStage;
+    private Button btnAbout, btnSave, btnClear, btnConnectDisconnect;
+    private HBox connectionForm;
+    private TextField tfHost, tfHostPort, tfNickname, tfRoom;
+    private Spinner<Integer> spnPenSize;
+    private ColorPicker colorPicker;
+
+    private LayeredImage layeredImage;
+    private LayeredImageStack imageStack;
+    private Canvas canvas;
+    private ImageView bgImageView, mgImageView;
 
     TCPHandler tcpHandler;
 
+
     @Override
     public void start(Stage primaryStage) throws IOException {
+        this.primaryStage = primaryStage;
         VBox root = new VBox();
         Scene scene = new Scene(root);
 
@@ -171,6 +176,7 @@ public void start(Stage primaryStage) throws IOException {
 
         root.getChildren().add(toolBarBottom);
 
+        btnSave.setOnAction(event -> savePNG());
         btnAbout.setOnAction(event -> showAboutWindow(primaryStage));
         btnClear.setOnAction(event -> clearCanvas());
         btnConnectDisconnect.setOnAction(event -> connect());
@@ -187,7 +193,13 @@ public void start(Stage primaryStage) throws IOException {
 
     @Override
     public void stop() {
-        stopHandler();
+        if (!tcpHandler.getIsConnectionDead()) {
+            stopHandler();
+        } else {
+            try {
+                tcpHandler.interrupt();
+            } catch (Exception ignored) { }
+        }
     }
 
     private void clearCanvas() {
@@ -231,10 +243,8 @@ private void connect() {
             clearCanvas();
 
 
-        } catch (UnknownHostException e) {
-            e.printStackTrace();
         } catch (IOException e) {
-            e.printStackTrace();
+            Alerts.showErrorAlert(e.toString(), e.getMessage());
         }
     }
 
@@ -293,6 +303,20 @@ public void snapshotCanvas() {
         }, snapshotParameters, img);
     }
 
+    public void savePNG() {
+        FileChooser fileChooser = new FileChooser();
+        fileChooser.setTitle("Save As PNG");
+        FileChooser.ExtensionFilter extFilter = new FileChooser.ExtensionFilter("PNG files (*.png)", "*.png");
+        fileChooser.getExtensionFilters().add(extFilter);
+
+        File outFile = fileChooser.showSaveDialog(primaryStage);
+        if (outFile != null) {
+            synchronized (imageStack) {
+                imageStack.saveAsPNG(outFile);
+            }
+        }
+    }
+
     private void showAboutWindow(Stage owner) {
         Stage aboutStage = new Stage();
 

multidraw-client/src/main/java/wit/pap/multidraw/client/gui/widgets/LayeredImageStack.java

@@ -1,14 +1,26 @@
 package wit.pap.multidraw.client.gui.widgets;
 
+import javafx.embed.swing.SwingFXUtils;
+import javafx.scene.SnapshotParameters;
 import javafx.scene.canvas.Canvas;
 import javafx.scene.canvas.GraphicsContext;
 import javafx.scene.image.Image;
 import javafx.scene.image.ImageView;
+import javafx.scene.image.WritableImage;
 import javafx.scene.layout.StackPane;
+import javafx.scene.paint.Color;
+import javafx.scene.paint.Paint;
+import wit.pap.multidraw.client.gui.utilities.Alerts;
 import wit.pap.multidraw.shared.globals.Globals;
 import wit.pap.multidraw.shared.BgraImage;
 import wit.pap.multidraw.shared.LayeredImage;
 
+import javax.imageio.ImageIO;
+import javax.swing.*;
+import java.awt.image.BufferedImage;
+import java.io.File;
+import java.io.IOException;
+
 public class LayeredImageStack extends StackPane {
     private LayeredImage layeredImage;
     private ImageView bgImageView, mgImageView;
@@ -66,6 +78,34 @@ private void draw(boolean clear) {
         }
     }
 
+    public void saveAsPNG(File outFile) {
+        if (fgCanvas == null || layeredImage == null)
+            return;
+
+        WritableImage writableImage = new WritableImage(Globals.IMAGE_WIDTH, Globals.IMAGE_HEIGHT);
+        SnapshotParameters params = new SnapshotParameters();
+        params.setFill(Color.TRANSPARENT);
+
+        fgCanvas.snapshot(params, writableImage);
+
+        BgraImage bg = getLayeredImage().getBackground(),
+                mg = getLayeredImage().getMiddleground(),
+                fg = BgraImage.fromFXImage(writableImage);
+        BgraImage result = BgraImage.overlayAll(bg, mg, fg);
+
+        if (result != null) {
+            BufferedImage bi = SwingFXUtils.fromFXImage(result.toWritableImage(), null);
+
+            try {
+                ImageIO.write(bi, "png", outFile);
+            } catch (IOException e) {
+                Alerts.showErrorAlert(e.toString(), e.getMessage());
+            }
+        }
+
+
+    }
+
     // Getter for the canvas to allow external manipulation if necessary
     public Canvas getFgCanvas() {
         return fgCanvas;