Make PDFDocument extend Device instead of implementing Drawable

Change PDFDocument to subclass Device rather than implement Drawable to
centralize resource management, align with Device lifecycle, and
simplify drawing logic.

This also fixes some complication with the windows implementation that
possibly chooses bad defaults and confuses screen DPI with PDF defaults
(72 DPI). Further the classes are made final and marked as experimental.

Author: Copilot

bundles/org.eclipse.swt/Eclipse SWT Printing/cocoa/org/eclipse/swt/printing/PDFDocument.java

@@ -43,14 +43,15 @@
  *
  * @see GC
  * @since 3.133
+ *
+ * @noreference This class is provisional API and subject to change. It is being made available to gather early feedback. The API or behavior may change in future releases as the implementation evolves based on user feedback.
  */
-public class PDFDocument implements Drawable {
-	Device device;
+public final class PDFDocument extends Device {
 	long pdfContext;
 	NSGraphicsContext graphicsContext;
 	boolean isGCCreated = false;
-	boolean disposed = false;
 	boolean pageStarted = false;
+	String filename;
 
 	/**
 	 * Width of the page in points (1/72 inch)
@@ -62,6 +63,16 @@ public class PDFDocument implements Drawable {
 	 */
 	double heightInPoints;
 
+	/**
+	 * Internal data class to pass PDF document parameters through
+	 * the Device constructor.
+	 */
+	static class PDFDocumentData extends DeviceData {
+		String filename;
+		double widthInPoints;
+		double heightInPoints;
+	}
+
 	/**
 	 * Constructs a new PDFDocument with the specified filename and page dimensions.
 	 * <p>
@@ -83,52 +94,38 @@ public class PDFDocument implements Drawable {
 	 * @see #dispose()
 	 */
 	public PDFDocument(String filename, double widthInPoints, double heightInPoints) {
-		this(null, filename, widthInPoints, heightInPoints);
+		super(checkData(filename, widthInPoints, heightInPoints));
 	}
 
 	/**
-	 * Constructs a new PDFDocument with the specified filename and page dimensions,
-	 * associated with the given device.
-	 * <p>
-	 * You must dispose the PDFDocument when it is no longer required.
-	 * </p>
-	 *
-	 * @param device the device to associate with this PDFDocument
-	 * @param filename the path to the PDF file to create
-	 * @param widthInPoints the width of each page in points (1/72 inch)
-	 * @param heightInPoints the height of each page in points (1/72 inch)
-	 *
-	 * @exception IllegalArgumentException <ul>
-	 *    <li>ERROR_NULL_ARGUMENT - if filename is null</li>
-	 *    <li>ERROR_INVALID_ARGUMENT - if width or height is not positive</li>
-	 * </ul>
-	 * @exception SWTError <ul>
-	 *    <li>ERROR_NO_HANDLES - if the PDF context could not be created</li>
-	 * </ul>
-	 *
-	 * @see #dispose()
+	 * Validates and prepares the data for construction.
 	 */
-	public PDFDocument(Device device, String filename, double widthInPoints, double heightInPoints) {
+	static PDFDocumentData checkData(String filename, double widthInPoints, double heightInPoints) {
 		if (filename == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
 		if (widthInPoints <= 0 || heightInPoints <= 0) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
+		PDFDocumentData data = new PDFDocumentData();
+		data.filename = filename;
+		data.widthInPoints = widthInPoints;
+		data.heightInPoints = heightInPoints;
+		return data;
+	}
+
+	/**
+	 * Creates the PDF device in the operating system.
+	 * This method is called before <code>init</code>.
+	 *
+	 * @param data the DeviceData which describes the receiver
+	 */
+	@Override
+	protected void create(DeviceData data) {
+		PDFDocumentData pdfData = (PDFDocumentData) data;
+		this.filename = pdfData.filename;
+		this.widthInPoints = pdfData.widthInPoints;
+		this.heightInPoints = pdfData.heightInPoints;
 
 		NSAutoreleasePool pool = null;
 		if (!NSThread.isMainThread()) pool = (NSAutoreleasePool) new NSAutoreleasePool().alloc().init();
 		try {
-			this.widthInPoints = widthInPoints;
-			this.heightInPoints = heightInPoints;
-
-			// Get device from the current display if not provided
-			if (device == null) {
-				try {
-					this.device = org.eclipse.swt.widgets.Display.getDefault();
-				} catch (Exception e) {
-					this.device = null;
-				}
-			} else {
-				this.device = device;
-			}
-
 			// Create CFURL from the filename
 			NSString path = NSString.stringWith(filename);
 			NSURL fileURL = NSURL.fileURLWithPath(path);
@@ -184,11 +181,11 @@ private void ensurePageStarted() {
 	 * </p>
 	 *
 	 * @exception SWTException <ul>
-	 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
+	 *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
 	 * </ul>
 	 */
 	public void newPage() {
-		if (disposed) SWT.error(SWT.ERROR_WIDGET_DISPOSED);
+		checkDevice();
 		NSAutoreleasePool pool = null;
 		if (!NSThread.isMainThread()) pool = (NSAutoreleasePool) new NSAutoreleasePool().alloc().init();
 		try {
@@ -216,11 +213,11 @@ public void newPage() {
 	 *    <li>ERROR_INVALID_ARGUMENT - if width or height is not positive</li>
 	 * </ul>
 	 * @exception SWTException <ul>
-	 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
+	 *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
 	 * </ul>
 	 */
 	public void newPage(double widthInPoints, double heightInPoints) {
-		if (disposed) SWT.error(SWT.ERROR_WIDGET_DISPOSED);
+		checkDevice();
 		if (widthInPoints <= 0 || heightInPoints <= 0) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
 
 		this.widthInPoints = widthInPoints;
@@ -234,11 +231,11 @@ public void newPage(double widthInPoints, double heightInPoints) {
 	 * @return the width in points (1/72 inch)
 	 *
 	 * @exception SWTException <ul>
-	 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
+	 *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
 	 * </ul>
 	 */
 	public double getWidth() {
-		if (disposed) SWT.error(SWT.ERROR_WIDGET_DISPOSED);
+		checkDevice();
 		return widthInPoints;
 	}
 
@@ -248,14 +245,47 @@ public double getWidth() {
 	 * @return the height in points (1/72 inch)
 	 *
 	 * @exception SWTException <ul>
-	 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
+	 *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
 	 * </ul>
 	 */
 	public double getHeight() {
-		if (disposed) SWT.error(SWT.ERROR_WIDGET_DISPOSED);
+		checkDevice();
 		return heightInPoints;
 	}
 
+	/**
+	 * Returns the DPI (dots per inch) of the PDF document.
+	 * PDF documents work in points where 1 point = 1/72 inch,
+	 * so the DPI is always 72.
+	 *
+	 * @return a point whose x coordinate is the horizontal DPI and whose y coordinate is the vertical DPI
+	 *
+	 * @exception SWTException <ul>
+	 *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
+	 * </ul>
+	 */
+	@Override
+	public Point getDPI() {
+		checkDevice();
+		return new Point(72, 72);
+	}
+
+	/**
+	 * Returns a rectangle describing the receiver's size and location.
+	 * The rectangle dimensions are in points (1/72 inch).
+	 *
+	 * @return the bounding rectangle
+	 *
+	 * @exception SWTException <ul>
+	 *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
+	 * </ul>
+	 */
+	@Override
+	public Rectangle getBounds() {
+		checkDevice();
+		return new Rectangle(0, 0, (int) widthInPoints, (int) heightInPoints);
+	}
+
 	/**
 	 * Invokes platform specific functionality to allocate a new GC handle.
 	 * <p>
@@ -273,7 +303,7 @@ public double getHeight() {
 	 */
 	@Override
 	public long internal_new_GC(GCData data) {
-		if (disposed) SWT.error(SWT.ERROR_WIDGET_DISPOSED);
+		checkDevice();
 		if (isGCCreated) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
 
 		NSAutoreleasePool pool = null;
@@ -290,18 +320,16 @@ public long internal_new_GC(GCData data) {
 				if ((data.style & mask) == 0) {
 					data.style |= SWT.LEFT_TO_RIGHT;
 				}
-				data.device = device;
+				data.device = this;
 				data.flippedContext = graphicsContext;
 				data.restoreContext = true;
 				NSSize size = new NSSize();
 				size.width = widthInPoints;
 				size.height = heightInPoints;
 				data.size = size;
-				if (device != null) {
-					data.background = device.getSystemColor(SWT.COLOR_WHITE).handle;
-					data.foreground = device.getSystemColor(SWT.COLOR_BLACK).handle;
-					data.font = device.getSystemFont();
-				}
+				data.background = getSystemColor(SWT.COLOR_WHITE).handle;
+				data.foreground = getSystemColor(SWT.COLOR_BLACK).handle;
+				data.font = getSystemFont();
 			}
 			isGCCreated = true;
 			return graphicsContext.id;
@@ -350,27 +378,12 @@ public boolean isAutoScalable() {
 	}
 
 	/**
-	 * Returns <code>true</code> if the PDFDocument has been disposed,
-	 * and <code>false</code> otherwise.
-	 *
-	 * @return <code>true</code> when the PDFDocument is disposed and <code>false</code> otherwise
+	 * Destroys the PDF document handle.
+	 * This method is called internally by the dispose
+	 * mechanism of the <code>Device</code> class.
 	 */
-	public boolean isDisposed() {
-		return disposed;
-	}
-
-	/**
-	 * Disposes of the operating system resources associated with
-	 * the PDFDocument. Applications must dispose of all PDFDocuments
-	 * that they allocate.
-	 * <p>
-	 * This method finalizes the PDF file and writes it to disk.
-	 * </p>
-	 */
-	public void dispose() {
-		if (disposed) return;
-		disposed = true;
-
+	@Override
+	protected void destroy() {
 		NSAutoreleasePool pool = null;
 		if (!NSThread.isMainThread()) pool = (NSAutoreleasePool) new NSAutoreleasePool().alloc().init();
 		try {