/*******************************************************************************
 * Copyright (c) 2000, 2025 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.awt;

/* AWT Imports */
import java.awt.*;
import java.awt.Canvas;
import java.awt.event.*;
import java.lang.reflect.*;

/* SWT Imports */
import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.internal.*;
import org.eclipse.swt.internal.gtk.*;
import org.eclipse.swt.internal.gtk3.*;
import org.eclipse.swt.internal.gtk4.*;
import org.eclipse.swt.widgets.*;
import org.eclipse.swt.widgets.Composite;


/**
 * This class provides a bridge between SWT and AWT, so that it
 * is possible to embed AWT components in SWT and vice versa.
 *
 * @see <a href="https://eclipse.dev/eclipse/swt/snippets/#awt">Swing/AWT snippets</a>
 * @see <a href="https://eclipse.dev/eclipse/swt/">Sample code and further information</a>
 *
 * @since 3.0
 */
public class SWT_AWT {

	/**
	 * The name of the embedded Frame class. The default class name
	 * for the platform will be used if <code>null</code>.
	 */
	public static String embeddedFrameClass;

	/**
	 * Key for looking up the embedded frame for a Composite using
	 * getData().
	 */
	static String EMBEDDED_FRAME_KEY = "org.eclipse.swt.awt.SWT_AWT.embeddedFrame";

static boolean loaded, swingInitialized;

static native final long getAWTHandle (Object canvas);
static native final void setDebug (Frame canvas, boolean debug);
static native final Object initFrame (long handle, String className);
static native final void validateWithBounds (Frame frame, int x, int y, int w, int h);
static native final void synthesizeWindowActivation (Frame frame, boolean doActivate);
static native final void registerListeners (Frame frame);

static synchronized void loadLibrary () {
	if (loaded) return;
	loaded = true;
	/*
	* Note that the jawt library is loaded explicitly
	* because it cannot be found by the library loader.
	* All exceptions are caught because the library may
	* have been loaded already.
	*/
	try {
		System.loadLibrary("jawt");
	} catch (Throwable e) {}
	Library.loadLibrary("swt-awt");
}

static synchronized void initializeSwing() {
	if (swingInitialized) return;
	swingInitialized = true;
	/*
	* Feature in GTK.  The default X error handler
	* for GTK calls exit() after printing the X error.
	* Normally, this isn't that big a problem for SWT
	* applications because they don't cause X errors.
	* However, sometimes X errors are generated by AWT
	* that make SWT exit.  The fix is to hide all X
	* errors when AWT is running.
	*/
	if (OS.isX11()) {
		GDK.gdk_x11_display_error_trap_push(GDK.gdk_display_get_default());
	}
	try {
		/* Initialize the default focus traversal policy */
		Class<?> clazz = Class.forName("javax.swing.UIManager");
		Method method = clazz.getMethod("getDefaults");
		if (method != null) method.invoke(clazz);
	} catch (Throwable e) {}
}

/**
 * Returns a <code>java.awt.Frame</code> which is the embedded frame
 * associated with the specified composite.
 *
 * @param parent the parent <code>Composite</code> of the <code>java.awt.Frame</code>
 * @return a <code>java.awt.Frame</code> the embedded frame or <code>null</code>.
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
 * </ul>
 *
 * @since 3.2
 */
public static Frame getFrame (Composite parent) {
	if (parent == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
	if ((parent.getStyle () & SWT.EMBEDDED) == 0) return null;
	return (Frame)parent.getData(EMBEDDED_FRAME_KEY);
}

/**
 * Creates a new <code>java.awt.Frame</code>. This frame is the root for
 * the AWT components that will be embedded within the composite. In order
 * for the embedding to succeed, the composite must have been created
 * with the SWT.EMBEDDED style.
 * <p>
 * IMPORTANT: As of JDK1.5, the embedded frame does not receive mouse events.
 * When a lightweight component is added as a child of the embedded frame,
 * the cursor does not change. In order to work around both these problems, it is
 * strongly recommended that a heavyweight component such as <code>java.awt.Panel</code>
 * be added to the frame as the root of all components.
 * </p>
 *
 * @param parent the parent <code>Composite</code> of the new <code>java.awt.Frame</code>
 * @return a <code>java.awt.Frame</code> to be the parent of the embedded AWT components
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the parent Composite does not have the SWT.EMBEDDED style</li>
 * </ul>
 *
 * @since 3.0
 */
public static Frame new_Frame (final Composite parent) {
	if (parent == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
	if ((parent.getStyle () & SWT.EMBEDDED) == 0) {
		SWT.error (SWT.ERROR_INVALID_ARGUMENT);
	}
	long handle = parent.embeddedHandle;
	/*
	 * Some JREs have implemented the embedded frame constructor to take an integer
	 * and other JREs take a long.  To handle this binary incompatibility, use
	 * reflection to create the embedded frame.
	 */
	String className = embeddedFrameClass != null ? embeddedFrameClass : "sun.awt.X11.XEmbeddedFrame";
	try {
		if (embeddedFrameClass != null) {
			Class.forName(className);
		}
		loadLibrary();
	} catch (ClassNotFoundException cne) {
		SWT.error (SWT.ERROR_NOT_IMPLEMENTED, cne);
	} catch (Throwable e) {
		SWT.error (SWT.ERROR_UNSPECIFIED , e, " [Error while starting AWT]");
	}
	initializeSwing ();
	final Frame [] frame = new Frame [1];
	Object object = initFrame(handle, className);
	if (object == null || !(object instanceof Frame)) {
		SWT.error (SWT.ERROR_UNSPECIFIED , new Throwable(), " [Error while starting AWT]");
	}
	frame[0] = (Frame) object;
	parent.setData(EMBEDDED_FRAME_KEY, frame[0]);
	if (Device.DEBUG) {
		setDebug(frame[0], true);
	}
	/* Call registerListeners() to make XEmbed focus traversal work */
	registerListeners(frame[0]);

	final AWTEventListener awtListener = event -> {
		if (event.getID() == WindowEvent.WINDOW_OPENED) {
			final Window window = (Window) event.getSource();
			if (window.getParent() == frame[0]) {
				parent.getDisplay().asyncExec(() -> {
					if (parent.isDisposed()) return;
					Shell shell = parent.getShell();
					long awtHandle = getAWTHandle(window);
					if (awtHandle == 0) return;

					long xWindow;
					if (GTK.GTK4) {
						xWindow = GDK.gdk_x11_surface_get_xid(GTK4.gtk_native_get_surface (GTK4.gtk_widget_get_native(shell.handle)));
					} else {
						xWindow = GDK.gdk_x11_window_get_xid (GTK3.gtk_widget_get_window (GTK3.gtk_widget_get_toplevel (shell.handle)));
					}

					OS.XSetTransientForHint(GDK.gdk_x11_display_get_xdisplay(GDK.gdk_display_get_default()), awtHandle, xWindow);
				});
			}
		}
	};

	frame[0].getToolkit().addAWTEventListener(awtListener, AWTEvent.WINDOW_EVENT_MASK);
	final Listener shellListener = e -> {
		switch (e.type) {
			case SWT.Deiconify:
				EventQueue.invokeLater(() -> frame[0].dispatchEvent (new WindowEvent (frame[0], WindowEvent.WINDOW_DEICONIFIED)));
				break;
			case SWT.Iconify:
				EventQueue.invokeLater(() -> frame[0].dispatchEvent (new WindowEvent (frame[0], WindowEvent.WINDOW_ICONIFIED)));
				break;
		}
	};
	Shell shell = parent.getShell ();
	shell.addListener (SWT.Deiconify, shellListener);
	shell.addListener (SWT.Iconify, shellListener);

	Listener listener = e -> {
		switch (e.type) {
			case SWT.Dispose:
				Shell shell1 = parent.getShell ();
				shell1.removeListener (SWT.Deiconify, shellListener);
				shell1.removeListener (SWT.Iconify, shellListener);
				parent.setVisible(false);
				EventQueue.invokeLater(() -> {
					frame[0].getToolkit().removeAWTEventListener(awtListener);
					frame[0].dispose ();
				});
				break;
			case SWT.Resize:
				final Rectangle clientArea = parent.getClientArea();
				EventQueue.invokeLater(() -> frame[0].setSize (clientArea.width, clientArea.height));
				break;
		}
	};
	parent.addListener (SWT.Dispose, listener);
	parent.addListener (SWT.Resize, listener);

	parent.getDisplay().asyncExec(() -> {
		if (parent.isDisposed()) return;
		final Rectangle clientArea = parent.getClientArea();
		EventQueue.invokeLater(() -> {
			frame[0].setSize (clientArea.width, clientArea.height);
			frame[0].validate ();
		});
	});
	return frame[0];
}

/**
 * Creates a new <code>Shell</code>. This Shell is the root for
 * the SWT widgets that will be embedded within the AWT canvas.
 *
 * @param display the display for the new Shell
 * @param parent the parent <code>java.awt.Canvas</code> of the new Shell
 * @return a <code>Shell</code> to be the parent of the embedded SWT widgets
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the display is null</li>
 *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the parent's peer is not created</li>
 * </ul>
 *
 * @since 3.0
 */
public static Shell new_Shell (final Display display, final Canvas parent) {
	if (display == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
	if (parent == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
	long handle = 0;
	try {
		loadLibrary ();
		handle = getAWTHandle (parent);
	} catch (Throwable e) {
		SWT.error (SWT.ERROR_NOT_IMPLEMENTED, e);
	}
	if (handle == 0) SWT.error (SWT.ERROR_INVALID_ARGUMENT, null, " [peer not created]");

	final Shell shell = Shell.gtk_new (display, handle);
	final ComponentListener listener = new ComponentAdapter () {
		@Override
		public void componentResized (ComponentEvent e) {
			display.syncExec (() -> {
				if (shell.isDisposed()) return;
				Dimension dim = parent.getSize ();
				shell.setSize (new Point(dim.width, dim.height));
			});
		}
	};
	parent.addComponentListener(listener);
	shell.addListener(SWT.Dispose, event -> parent.removeComponentListener(listener));
	shell.setVisible (true);
	return shell;
}
}
