Support saving any page snapshot to a file

sampler/src/main/java/atlantafx/sampler/Launcher.java

@@ -40,7 +40,8 @@ public class Launcher extends Application {
 
     public static final List<KeyCodeCombination> SUPPORTED_HOTKEYS = List.of(
         new KeyCodeCombination(KeyCode.SLASH),
-        new KeyCodeCombination(KeyCode.T, KeyCombination.CONTROL_DOWN)
+        new KeyCodeCombination(KeyCode.T, KeyCombination.CONTROL_DOWN),
+        new KeyCodeCombination(KeyCode.W, KeyCombination.CONTROL_DOWN)
     );
 
     public static void main(String[] args) {

sampler/src/main/java/atlantafx/sampler/layout/MainLayer.java

@@ -6,20 +6,30 @@ import static atlantafx.sampler.event.PageEvent.Action;
 import static javafx.scene.layout.Priority.ALWAYS;
 
 import atlantafx.sampler.event.DefaultEventBus;
+import atlantafx.sampler.event.HotkeyEvent;
 import atlantafx.sampler.event.PageEvent;
 import atlantafx.sampler.event.ThemeEvent;
 import atlantafx.sampler.layout.MainModel.SubLayer;
 import atlantafx.sampler.page.Page;
 import atlantafx.sampler.theme.ThemeManager;
 import java.io.IOException;
+import java.nio.file.Paths;
 import java.util.Objects;
 import javafx.animation.FadeTransition;
 import javafx.application.Platform;
+import javafx.embed.swing.SwingFXUtils;
+import javafx.scene.SnapshotParameters;
+import javafx.scene.image.WritableImage;
+import javafx.scene.input.KeyCode;
+import javafx.scene.input.KeyCodeCombination;
+import javafx.scene.input.KeyCombination;
 import javafx.scene.layout.BorderPane;
 import javafx.scene.layout.HBox;
 import javafx.scene.layout.Pane;
 import javafx.scene.layout.StackPane;
+import javafx.stage.FileChooser;
 import javafx.util.Duration;
+import javax.imageio.ImageIO;
 
 class MainLayer extends BorderPane {
 
@@ -42,6 +52,38 @@ class MainLayer extends BorderPane {
 
         // keyboard navigation won't work without focus
         Platform.runLater(sidebar::begForFocus);
+
+        var snapshotKeys = new KeyCodeCombination(KeyCode.W, KeyCombination.CONTROL_DOWN);
+        DefaultEventBus.getInstance().subscribe(HotkeyEvent.class, e -> {
+            if (Objects.equals(e.getKeys(), snapshotKeys)) {
+                final Page page = (Page) subLayerPane.getChildren().stream()
+                    .filter(c -> c instanceof Page)
+                    .findFirst()
+                    .orElse(null);
+                if (page == null || page.getSnapshotTarget() == null) {
+                    return;
+                }
+
+                var fileChooser = new FileChooser();
+                fileChooser.setInitialDirectory(Paths.get(System.getProperty("user.home")).toFile());
+                fileChooser.setInitialFileName("snapshot.png");
+                fileChooser.getExtensionFilters().addAll(
+                    new FileChooser.ExtensionFilter("Image Files", "*.png")
+                );
+
+                var file = fileChooser.showSaveDialog(getScene().getWindow());
+                if (file == null) {
+                    return;
+                }
+
+                try {
+                    WritableImage img = page.getSnapshotTarget().snapshot(new SnapshotParameters(), null);
+                    ImageIO.write(SwingFXUtils.fromFXImage(img, null), "png", file);
+                } catch (IOException ex) {
+                    throw new RuntimeException(ex);
+                }
+            }
+        });
     }
 
     private void createView() {

sampler/src/main/java/atlantafx/sampler/page/AbstractPage.java

@@ -20,6 +20,7 @@ import org.jetbrains.annotations.Nullable;
 public abstract class AbstractPage extends StackPane implements Page {
 
     protected final VBox userContent = new VBox();
+    protected final StackPane userContentArea = new StackPane(userContent);
     protected Overlay overlay;
     protected boolean isRendered = false;
 
@@ -33,7 +34,6 @@ public abstract class AbstractPage extends StackPane implements Page {
     }
 
     protected void createPageLayout() {
-        var userContentArea = new StackPane(userContent);
         userContentArea.setAlignment(Pos.TOP_CENTER);
         userContent.setMinWidth(Math.min(Page.MAX_WIDTH, 800));
         userContent.setMaxWidth(Math.min(Page.MAX_WIDTH, 800));
@@ -65,6 +65,11 @@ public abstract class AbstractPage extends StackPane implements Page {
         return URI.create(String.format(JFX_JAVADOC_URI_TEMPLATE, "control/" + getName()));
     }
 
+    @Override
+    public Node getSnapshotTarget() {
+        return userContentArea;
+    }
+
     @Override
     public void reset() {
     }

sampler/src/main/java/atlantafx/sampler/page/OutlinePage.java

@@ -37,6 +37,7 @@ public abstract class OutlinePage extends StackPane implements Page {
 
     protected final ScrollPane scrollPane = new ScrollPane();
     protected final VBox userContent = new VBox();
+    protected final StackPane userContentArea = new StackPane(userContent);
     protected final Outline outline = new Outline(createOutlineHandler());
 
     protected Overlay overlay;
@@ -52,7 +53,6 @@ public abstract class OutlinePage extends StackPane implements Page {
     }
 
     protected void createPageLayout() {
-        var userContentArea = new StackPane(userContent);
         StackPane.setMargin(userContent, new Insets(0, OUTLINE_WIDTH, 0, 0));
         userContent.setMinWidth(Page.MAX_WIDTH - OUTLINE_WIDTH - 100);
         userContent.setMaxWidth(Page.MAX_WIDTH - OUTLINE_WIDTH - 100);
@@ -177,6 +177,11 @@ public abstract class OutlinePage extends StackPane implements Page {
         return URI.create(String.format(JFX_JAVADOC_URI_TEMPLATE, "control/" + getName()));
     }
 
+    @Override
+    public Node getSnapshotTarget() {
+        return userContentArea;
+    }
+
     @Override
     public void reset() {
     }

sampler/src/main/java/atlantafx/sampler/page/Page.java

@@ -27,6 +27,7 @@ import javafx.scene.control.MenuItem;
 import javafx.scene.input.KeyCode;
 import javafx.scene.input.KeyCodeCombination;
 import javafx.scene.layout.HBox;
+import javafx.scene.layout.Pane;
 import net.datafaker.Faker;
 import org.jetbrains.annotations.Nullable;
 import org.kordamp.ikonli.feather.Feather;
@@ -58,6 +59,8 @@ public interface Page {
 
     @Nullable URI getJavadocUri();
 
+    @Nullable Node getSnapshotTarget();
+
     void reset();
 
     default <T> List<T> generate(Supplier<T> supplier, int count) {

sampler/src/main/java/atlantafx/sampler/page/showcase/OverviewPage.java

@@ -11,6 +11,7 @@ import java.io.IOException;
 import java.net.URI;
 import javafx.fxml.FXMLLoader;
 import javafx.geometry.Pos;
+import javafx.scene.Node;
 import javafx.scene.Parent;
 import javafx.scene.control.ScrollPane;
 import javafx.scene.layout.Pane;
@@ -21,6 +22,7 @@ import org.jetbrains.annotations.Nullable;
 public final class OverviewPage extends ScrollPane implements Page {
 
     public static final String NAME = "Overview";
+    private VBox wrapper;
 
     @Override
     public String getName() {
@@ -31,7 +33,7 @@ public final class OverviewPage extends ScrollPane implements Page {
         super();
 
         try {
-            var wrapper = new VBox();
+            wrapper = new VBox();
             wrapper.setAlignment(Pos.TOP_CENTER);
 
             var loader = new FXMLLoader(
@@ -72,6 +74,11 @@ public final class OverviewPage extends ScrollPane implements Page {
         return null;
     }
 
+    @Override
+    public Node getSnapshotTarget() {
+        return wrapper;
+    }
+
     @Override
     public void reset() {
     }

sampler/src/main/java/atlantafx/sampler/page/showcase/ShowcasePage.java

@@ -111,6 +111,11 @@ public abstract class ShowcasePage extends StackPane implements Page {
         return null;
     }
 
+    @Override
+    public Node getSnapshotTarget() {
+        return showCaseContent;
+    }
+
     @Override
     public void reset() {
     }