/*******************************************************************************
 * Copyright (c) 2000, 2017 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.graphics;


import java.lang.ref.*;
import java.util.*;
import java.util.concurrent.*;

import org.eclipse.swt.*;
import org.eclipse.swt.internal.*;
import org.eclipse.swt.internal.gdip.*;
import org.eclipse.swt.internal.win32.*;
import org.eclipse.swt.widgets.*;

/**
 * This class is the abstract superclass of all device objects,
 * such as the Display device and the Printer device. Devices
 * can have a graphics context (GC) created for them, and they
 * can be drawn on by sending messages to the associated GC.
 *
 * @see <a href="https://eclipse.dev/eclipse/swt/">Sample code and further information</a>
 */
public abstract class Device implements Drawable {

	/* Debugging */
	public static boolean DEBUG;
	boolean debug = DEBUG;
	boolean tracking = DEBUG;
	Error [] errors;
	Object [] objects;
	Object trackingLock;

	/* System Font */
	Font systemFont;

	/* Font Enumeration */
	int nFonts = 256;
	LOGFONT [] logFonts;
	TEXTMETRIC metrics;
	int[] pixels;

	/* Scripts */
	long [] scripts;

	/* Advanced Graphics */
	long [] gdipToken;
	long fontCollection;
	String[] loadedFonts;

	volatile boolean disposed;
	private Set<ResourceReference> resourcesWithZoomSupport = ConcurrentHashMap.newKeySet();

	/*
	* TEMPORARY CODE. When a graphics object is
	* created and the device parameter is null,
	* the current Display is used. This presents
	* a problem because SWT graphics does not
	* reference classes in SWT widgets. The correct
	* fix is to remove this feature. Unfortunately,
	* too many application programs rely on this
	* feature.
	*/
	protected static Device CurrentDevice;
	protected static Runnable DeviceFinder;
	static {
		try {
			Class.forName ("org.eclipse.swt.widgets.Display"); //$NON-NLS-1$
		} catch (ClassNotFoundException e) {}
	}

/*
* TEMPORARY CODE.
*/
static synchronized Device getDevice () {
	if (DeviceFinder != null) DeviceFinder.run();
	Device device = CurrentDevice;
	CurrentDevice = null;
	return device;
}

/**
 * Constructs a new instance of this class.
 * <p>
 * You must dispose the device when it is no longer required.
 * </p>
 *
 * @see #create
 * @see #init
 *
 * @since 3.1
 */
public Device() {
	this(null);
}

/**
 * Constructs a new instance of this class.
 * <p>
 * You must dispose the device when it is no longer required.
 * </p>
 *
 * @param data the DeviceData which describes the receiver
 *
 * @see #create
 * @see #init
 * @see DeviceData
 */
public Device(DeviceData data) {
	synchronized (Device.class) {
		if (data != null) {
			debug = data.debug;
			tracking = data.tracking;
		}
		if (tracking) {
			startTracking();
		}
		create (data);
		init ();
	}
}

/**
 *
 * @exception SWTException <ul>
 *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * @since 3.115
 */
public boolean isTracking() {
	checkDevice();
	return tracking;
}

/**
 * @exception SWTException <ul>
 *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * @since 3.115
 */
public void setTracking(boolean tracking) {
	checkDevice();
	if (tracking == this.tracking) {
		return;
	}
	this.tracking = tracking;
	if (tracking) {
		startTracking();
	} else {
		stopTracking();
	}
}

private void startTracking() {
	errors = new Error [128];
	objects = new Object [128];
	trackingLock = new Object ();
}

private void stopTracking() {
	synchronized (trackingLock) {
		objects = null;
		errors = null;
		trackingLock = null;
	}
}



void addFont (String font) {
	if (loadedFonts == null) loadedFonts = new String [4];
	int length = loadedFonts.length;
	for (int i=0; i<length; i++) {
		if (font.equals(loadedFonts [i])) return;
	}
	int index = 0;
	while (index < length) {
		if (loadedFonts [index] == null) break;
		index++;
	}
	if (index == length) {
		String [] temp = new String [length + 4];
		System.arraycopy (loadedFonts, 0, temp, 0, length);
		loadedFonts = temp;
	}
	loadedFonts [index] = font;
}

/**
 * Throws an <code>SWTException</code> if the receiver can not
 * be accessed by the caller. This may include both checks on
 * the state of the receiver and more generally on the entire
 * execution context. This method <em>should</em> be called by
 * device implementors to enforce the standard SWT invariants.
 * <p>
 * Currently, it is an error to invoke any method (other than
 * <code>isDisposed()</code> and <code>dispose()</code>) on a
 * device that has had its <code>dispose()</code> method called.
 * </p><p>
 * In future releases of SWT, there may be more or fewer error
 * checks and exceptions may be thrown for different reasons.
 * </p>
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
protected void checkDevice () {
	if (disposed) SWT.error(SWT.ERROR_DEVICE_DISPOSED);
}

void checkGDIP() {
	if (gdipToken != null) return;
	long [] token = new long [1];
	GdiplusStartupInput input = new GdiplusStartupInput ();
	input.GdiplusVersion = 1;
	if (Gdip.GdiplusStartup (token, input, 0) != 0) SWT.error (SWT.ERROR_NO_HANDLES);
	gdipToken = token;
	if (loadedFonts != null) {
		fontCollection = Gdip.PrivateFontCollection_new();
		if (fontCollection == 0) SWT.error(SWT.ERROR_NO_HANDLES);
		for (String path : loadedFonts) {
			if (path == null) break;
			int length = path.length();
			char [] buffer = new char [length + 1];
			path.getChars(0, length, buffer, 0);
			Gdip.PrivateFontCollection_AddFontFile(fontCollection, buffer);
		}
		loadedFonts = null;
	}
}

/**
 * Creates the device in the operating system.  If the device
 * does not have a handle, this method may do nothing depending
 * on the device.
 * <p>
 * This method is called before <code>init</code>.
 * </p><p>
 * Subclasses are supposed to reimplement this method and not
 * call the <code>super</code> implementation.
 * </p>
 *
 * @param data the DeviceData which describes the receiver
 *
 * @see #init
 */
protected void create (DeviceData data) {
}

int computePixels(float height, int zoom) {
	long hDC = internal_new_GC (null);
	int pixels = -(int)(0.5f + (height / calculateFontConversionFactor(hDC, zoom)));
	internal_dispose_GC (hDC, null);
	return pixels;
}

float computePoints(LOGFONT logFont, long hFont) {
	return computePoints(logFont, hFont, SWT.DEFAULT);
}

private float calculateFontConversionFactor(long hDC, int zoom) {
	float conversionFactor = 72f;
	if (isAutoScalable() && zoom != SWT.DEFAULT) {
		// For auto scalable devices we need to use a dynamic
		// DPI value that is extracted from the zoom
		conversionFactor /= DPIUtil.mapZoomToDPI(zoom);
	} else {
		conversionFactor /= OS.GetDeviceCaps(hDC, OS.LOGPIXELSY);
	}
	return conversionFactor;
}

float computePoints(LOGFONT logFont, long hFont, int zoom) {
	long hDC = internal_new_GC (null);

	float conversionFactor = calculateFontConversionFactor(hDC, zoom);
	int pixels = 0;
	if (logFont.lfHeight > 0) {
		/*
		 * Feature in Windows. If the lfHeight of the LOGFONT structure
		 * is positive, the lfHeight measures the height of the entire
		 * cell, including internal leading, in logical units. Since the
		 * height of a font in points does not include the internal leading,
		 * we must subtract the internal leading, which requires a TEXTMETRIC.
		 */
		long oldFont = OS.SelectObject(hDC, hFont);
		TEXTMETRIC lptm = new TEXTMETRIC ();
		OS.GetTextMetrics(hDC, lptm);
		OS.SelectObject(hDC, oldFont);
		pixels = logFont.lfHeight - lptm.tmInternalLeading;
	} else {
		pixels = -logFont.lfHeight;
	}
	internal_dispose_GC (hDC, null);
	return pixels * conversionFactor;
}

/**
 * Destroys the device in the operating system and releases
 * the device's handle.  If the device does not have a handle,
 * this method may do nothing depending on the device.
 * <p>
 * This method is called after <code>release</code>.
 * </p><p>
 * Subclasses are supposed to reimplement this method and not
 * call the <code>super</code> implementation.
 * </p>
 *
 * @see #dispose
 * @see #release
 */
protected void destroy () {
}

/**
 * Disposes of the operating system resources associated with
 * the receiver. After this method has been invoked, the receiver
 * will answer <code>true</code> when sent the message
 * <code>isDisposed()</code>.
 *
 * @see #release
 * @see #destroy
 * @see #checkDevice
 */
public void dispose () {
	synchronized (Device.class) {
		try (ExceptionStash exceptions = new ExceptionStash ()) {
			if (isDisposed ()) return;
			checkDevice ();

			try {
				release ();
			} catch (Error | RuntimeException ex) {
				exceptions.stash (ex);
			}

			destroy ();
			disposed = true;
			if (tracking) {
				synchronized (trackingLock) {
					printErrors ();
					objects = null;
					errors = null;
					trackingLock = null;
				}
			}
		}
	}
}

void dispose_Object (Object object) {
	synchronized (trackingLock) {
		for (int i=0; i<objects.length; i++) {
			if (objects [i] == object) {
				objects [i] = null;
				errors [i] = null;
				return;
			}
		}
	}
}

long EnumFontFamProc (long lpelfe, long lpntme, long FontType, long lParam) {
	boolean isScalable = ((int)FontType & OS.RASTER_FONTTYPE) == 0;
	boolean scalable = lParam == 1;
	if (isScalable == scalable) {
		/* Add the log font to the list of log fonts */
		if (nFonts == logFonts.length) {
			LOGFONT [] newLogFonts = new LOGFONT [logFonts.length + 128];
			System.arraycopy (logFonts, 0, newLogFonts, 0, nFonts);
			logFonts = newLogFonts;
			int[] newPixels = new int[newLogFonts.length];
			System.arraycopy (pixels, 0, newPixels, 0, nFonts);
			pixels = newPixels;
		}
		LOGFONT logFont = logFonts [nFonts];
		if (logFont == null) logFont = new LOGFONT ();
		OS.MoveMemory (logFont, lpelfe, LOGFONT.sizeof);
		logFonts [nFonts] = logFont;
		if (logFont.lfHeight > 0) {
			/*
			 * Feature in Windows. If the lfHeight of the LOGFONT structure
			 * is positive, the lfHeight measures the height of the entire
			 * cell, including internal leading, in logical units. Since the
			 * height of a font in points does not include the internal leading,
			 * we must subtract the internal leading, which requires a TEXTMETRIC,
			 * which in turn requires font creation.
			 */
			OS.MoveMemory(metrics, lpntme, TEXTMETRIC.sizeof);
			pixels[nFonts] = logFont.lfHeight - metrics.tmInternalLeading;
		} else {
			pixels[nFonts] = -logFont.lfHeight;
		}
		nFonts++;
	}
	return 1;
}

/**
 * Returns a rectangle describing the receiver's size and location.
 *
 * @return the bounding rectangle
 *
 * @exception SWTException <ul>
 *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public Rectangle getBounds() {
	checkDevice ();
	return Win32DPIUtils.pixelToPoint(getBoundsInPixels(), getDeviceZoom());
}

private Rectangle getBoundsInPixels () {
	long hDC = internal_new_GC (null);
	int width = OS.GetDeviceCaps (hDC, OS.HORZRES);
	int height = OS.GetDeviceCaps (hDC, OS.VERTRES);
	internal_dispose_GC (hDC, null);
	return new Rectangle (0, 0, width, height);
}

/**
 * Returns a <code>DeviceData</code> based on the receiver.
 * Modifications made to this <code>DeviceData</code> will not
 * affect the receiver.
 *
 * @return a <code>DeviceData</code> containing the device's data and attributes
 *
 * @exception SWTException <ul>
 *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 *
 * @see DeviceData
 */
public DeviceData getDeviceData () {
	checkDevice();
	DeviceData data = new DeviceData ();
	data.debug = debug;
	data.tracking = tracking;
	if (tracking) {
		synchronized (trackingLock) {
			int count = 0, length = objects.length;
			for (int i=0; i<length; i++) {
				if (objects [i] != null) count++;
			}
			int index = 0;
			data.objects = new Object [count];
			data.errors = new Error [count];
			for (int i=0; i<length; i++) {
				if (objects [i] != null) {
					data.objects [index] = objects [i];
					data.errors [index] = errors [i];
					index++;
				}
			}
		}
	} else {
		data.objects = new Object [0];
		data.errors = new Error [0];
	}
	return data;
}

/**
 * Returns a rectangle which describes the area of the
 * receiver which is capable of displaying data.
 *
 * @return the client area
 *
 * @exception SWTException <ul>
 *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 *
 * @see #getBounds
 */
public Rectangle getClientArea () {
	return getBounds ();
}

/**
 * Returns the bit depth of the screen, which is the number of
 * bits it takes to represent the number of unique colors that
 * the screen is currently capable of displaying. This number
 * will typically be one of 1, 8, 15, 16, 24 or 32.
 *
 * @return the depth of the screen
 *
 * @exception SWTException <ul>
 *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public int getDepth () {
	checkDevice ();
	long hDC = internal_new_GC (null);
	int bits = OS.GetDeviceCaps (hDC, OS.BITSPIXEL);
	int planes = OS.GetDeviceCaps (hDC, OS.PLANES);
	internal_dispose_GC (hDC, null);
	return bits * planes;
}

/**
 * Returns a point whose x coordinate is the logical horizontal
 * dots per inch of the display, and whose y coordinate
 * is the logical vertical dots per inch of the display.
 *
 * <p><b>Caution:</b> this method may yield unexpected results when using
 * multiple monitors. This method returns a value based on the
 * primary monitor DPI on startup (depending on the OS).</p>
 *
 * <p>Note: This method returns a DPI value under consideration of the
 * autoscale mode. If the autoscaled zoom is different to the native
 * zoom, the returned DPI will be calculated relative from the autoscaled
 * zoom to the DPI of the native zoom, e.g. in the Windows implementation
 * (with a base DPI of 96) this method will return 120 with autoscale mode
 * <i>integer</i> and 96 with autoscale mode <i>quarter</i>.</p>
 *
 * @return the horizontal and vertical DPI
 *
 * @exception SWTException <ul>
 *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public Point getDPI () {
	checkDevice ();
	long hDC = internal_new_GC (null);
	int dpiX = OS.GetDeviceCaps (hDC, OS.LOGPIXELSX);
	int primaryZoomAtStartup = DPIUtil.mapDPIToZoom(dpiX);
	int dpiY = OS.GetDeviceCaps (hDC, OS.LOGPIXELSY);
	internal_dispose_GC (hDC, null);
	return Win32DPIUtils.pixelToPointAsLocation(new Point (dpiX, dpiY), DPIUtil.getZoomForAutoscaleProperty(primaryZoomAtStartup));
}

/**
 * Returns DPI in x direction. In the modern monitors DPI for
 * X and Y directions is same.
 *
 * @return the horizontal DPI
 */
int _getDPIx () {
	long hDC = internal_new_GC (null);
	int dpi = OS.GetDeviceCaps (hDC, OS.LOGPIXELSX);
	internal_dispose_GC (hDC, null);
	return dpi;
}
/**
 * Returns <code>FontData</code> objects which describe
 * the fonts that match the given arguments. If the
 * <code>faceName</code> is null, all fonts will be returned.
 *
 * @param faceName the name of the font to look for, or null
 * @param scalable if true only scalable fonts are returned, otherwise only non-scalable fonts are returned.
 * @return the matching font data
 *
 * @exception SWTException <ul>
 *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public FontData [] getFontList (String faceName, boolean scalable) {
	checkDevice ();

	/* Create the callback */
	Callback callback = new Callback (this, "EnumFontFamProc", 4); //$NON-NLS-1$
	long lpEnumFontFamProc = callback.getAddress ();

	/* Initialize the instance variables */
	metrics = new TEXTMETRIC ();
	pixels = new int[nFonts];
	logFonts = new LOGFONT [nFonts];
	for (int i=0; i<logFonts.length; i++) {
		logFonts [i] = new LOGFONT ();
	}
	nFonts = 0;

	/* Enumerate */
	int offset = 0;
	long hDC = internal_new_GC (null);
	if (faceName == null) {
		/* The user did not specify a face name, so they want all versions of all available face names */
		OS.EnumFontFamilies (hDC, null, lpEnumFontFamProc, scalable ? 1 : 0);

		/**
		 * For bitmapped fonts, EnumFontFamilies only enumerates once for each font, regardless
		 * of how many styles are available. If the user wants bitmapped fonts, enumerate on
		 * each face name now.
		 */
		offset = nFonts;
		for (int i=0; i<offset; i++) {
			LOGFONT lf = logFonts [i];
			OS.EnumFontFamilies (hDC, lf.lfFaceName, lpEnumFontFamProc, scalable ? 1 : 0);
		}
	} else {
		TCHAR lpFaceName = new TCHAR (0, faceName, true);
		OS.EnumFontFamilies (hDC, lpFaceName.chars, lpEnumFontFamProc, scalable ? 1 : 0);
	}
	int logPixelsY = OS.GetDeviceCaps(hDC, OS.LOGPIXELSY);
	internal_dispose_GC (hDC, null);

	/* Create the fontData from the logfonts */
	int count = 0;
	FontData [] result = new FontData [nFonts - offset];
	for (int i=offset; i<nFonts; i++) {
		FontData fd = FontData.win32_new (logFonts [i], pixels [i] * 72f / logPixelsY);
		int j;
		for (j = 0; j < count; j++) {
			if (fd.equals (result [j])) break;
		}
		if (j == count) result [count++] = fd;
	}
	if (count != result.length) {
		FontData [] newResult = new FontData [count];
		System.arraycopy (result, 0, newResult, 0, count);
		result = newResult;
	}

	/* Clean up */
	callback.dispose ();
	logFonts = null;
	pixels = null;
	metrics = null;
	return result;
}

String getLastError () {
	int error = OS.GetLastError();
	if (error == 0) return ""; //$NON-NLS-1$
	return " [GetLastError=0x" + Integer.toHexString(error) + "]"; //$NON-NLS-1$ //$NON-NLS-2$
}

/**
 * Returns the matching standard color for the given
 * constant, which should be one of the color constants
 * specified in class <code>SWT</code>. Any value other
 * than one of the SWT color constants which is passed
 * in will result in the color black. This color should
 * not be freed because it was allocated by the system,
 * not the application.
 *
 * @param id the color constant
 * @return the matching color
 *
 * @exception SWTException <ul>
 *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 *
 * @see SWT
 */
public Color getSystemColor (int id) {
	checkDevice ();
	int pixel = 0x00000000;
	int alpha = 255;
	switch (id) {
		case SWT.COLOR_TRANSPARENT:			alpha = 0;
		case SWT.COLOR_WHITE:				pixel = 0x00FFFFFF;  break;
		case SWT.COLOR_BLACK:				pixel = 0x00000000;  break;
		case SWT.COLOR_RED:					pixel = 0x000000FF;  break;
		case SWT.COLOR_DARK_RED:			pixel = 0x00000080;  break;
		case SWT.COLOR_GREEN:				pixel = 0x0000FF00;  break;
		case SWT.COLOR_DARK_GREEN:			pixel = 0x00008000;  break;
		case SWT.COLOR_YELLOW:				pixel = 0x0000FFFF;  break;
		case SWT.COLOR_DARK_YELLOW:			pixel = 0x00008080;  break;
		case SWT.COLOR_BLUE:				pixel = 0x00FF0000;  break;
		case SWT.COLOR_DARK_BLUE:			pixel = 0x00800000;  break;
		case SWT.COLOR_MAGENTA:				pixel = 0x00FF00FF;  break;
		case SWT.COLOR_DARK_MAGENTA:		pixel = 0x00800080;  break;
		case SWT.COLOR_CYAN:				pixel = 0x00FFFF00;  break;
		case SWT.COLOR_DARK_CYAN:			pixel = 0x00808000;  break;
		case SWT.COLOR_GRAY:				pixel = 0x00C0C0C0;  break;
		case SWT.COLOR_DARK_GRAY:			pixel = 0x00808080;  break;
	}
	return Color.win32_new (this, pixel, alpha);
}

/**
 * Returns a reasonable font for applications to use.
 * On some platforms, this will match the "default font"
 * or "system font" if such can be found.  This font
 * should not be freed because it was allocated by the
 * system, not the application.
 * <p>
 * Typically, applications which want the default look
 * should simply not set the font on the widgets they
 * create. Widgets are always created with the correct
 * default font for the class of user-interface component
 * they represent.
 * </p>
 *
 * @return a font
 *
 * @exception SWTException <ul>
 *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public Font getSystemFont () {
	checkDevice ();
	long hFont = OS.GetStockObject (OS.SYSTEM_FONT);
	return Font.win32_new (this, hFont);
}

/**
 * Returns <code>true</code> if the underlying window system prints out
 * warning messages on the console, and <code>setWarnings</code>
 * had previously been called with <code>true</code>.
 *
 * @return <code>true</code>if warnings are being handled, and <code>false</code> otherwise
 *
 * @exception SWTException <ul>
 *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public boolean getWarnings () {
	checkDevice ();
	return false;
}

/**
 * Initializes any internal resources needed by the
 * device.
 * <p>
 * This method is called after <code>create</code>.
 * </p><p>
 * If subclasses reimplement this method, they must
 * call the <code>super</code> implementation.
 * </p>
 *
 * @see #create
 */
protected void init () {
	if (debug) {
		OS.GdiSetBatchLimit(1);
	}

	/* Initialize the system font slot */
	systemFont = getSystemFont();

	/* Initialize scripts list */
	long [] ppSp = new long [1];
	int [] piNumScripts = new int [1];
	OS.ScriptGetProperties (ppSp, piNumScripts);
	scripts = new long [piNumScripts [0]];
	// TODO do all the movememories here
	OS.MoveMemory (scripts, ppSp [0], scripts.length * C.PTR_SIZEOF);
}
/**
 * Invokes platform specific functionality to allocate a new GC handle.
 * <p>
 * <b>IMPORTANT:</b> This method is <em>not</em> part of the public
 * API for <code>Device</code>. It is marked public only so that it
 * can be shared within the packages provided by SWT. It is not
 * available on all platforms, and should never be called from
 * application code.
 * </p>
 *
 * @param data the platform specific GC data
 * @return the platform specific GC handle
 *
 * @noreference This method is not intended to be referenced by clients.
 */
@Override
public abstract long internal_new_GC (GCData data);

/**
 * Invokes platform specific functionality to dispose a GC handle.
 * <p>
 * <b>IMPORTANT:</b> This method is <em>not</em> part of the public
 * API for <code>Device</code>. It is marked public only so that it
 * can be shared within the packages provided by SWT. It is not
 * available on all platforms, and should never be called from
 * application code.
 * </p>
 *
 * @param hDC the platform specific GC handle
 * @param data the platform specific GC data
 *
 * @noreference This method is not intended to be referenced by clients.
 */
@Override
public abstract void /*long*/ internal_dispose_GC (long hDC, GCData data);

/**
 * Returns <code>true</code> if the device has been disposed,
 * and <code>false</code> otherwise.
 * <p>
 * This method gets the dispose state for the device.
 * When a device has been disposed, it is an error to
 * invoke any other method using the device.
 *
 * @return <code>true</code> when the device is disposed and <code>false</code> otherwise
 */
public boolean isDisposed () {
	return disposed;
}

/**
 * Loads the font specified by a file.  The font will be
 * present in the list of fonts available to the application.
 *
 * @param path the font file path
 * @return whether the font was successfully loaded
 *
 * @exception SWTException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if path is null</li>
 *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 *
 * @see Font
 *
 * @since 3.3
 */
public boolean loadFont (String path) {
	checkDevice();
	if (path == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
	TCHAR lpszFilename = new TCHAR (0, path, true);
	boolean loaded = OS.AddFontResourceEx (lpszFilename, OS.FR_PRIVATE, 0) != 0;
	if (loaded) {
		if (gdipToken != null) {
			if (fontCollection == 0) {
				fontCollection = Gdip.PrivateFontCollection_new();
				if (fontCollection == 0) SWT.error(SWT.ERROR_NO_HANDLES);
			}
			int length = path.length();
			char [] buffer = new char [length + 1];
			path.getChars(0, length, buffer, 0);
			Gdip.PrivateFontCollection_AddFontFile(fontCollection, buffer);
		} else {
			addFont(path);
		}
	}
	return loaded;
}

void new_Object (Object object) {
	synchronized (trackingLock) {
		for (int i=0; i<objects.length; i++) {
			if (objects [i] == null) {
				objects [i] = object;
				errors [i] = new Error ();
				return;
			}
		}
		Object [] newObjects = new Object [objects.length + 128];
		System.arraycopy (objects, 0, newObjects, 0, objects.length);
		newObjects [objects.length] = object;
		objects = newObjects;
		Error [] newErrors = new Error [errors.length + 128];
		System.arraycopy (errors, 0, newErrors, 0, errors.length);
		newErrors [errors.length] = new Error ();
		errors = newErrors;
	}
}

void printErrors () {
	if (!DEBUG) return;
	if (tracking) {
		synchronized (trackingLock) {
			if (objects == null || errors == null) return;
			int objectCount = 0;
			int colors = 0, cursors = 0, fonts = 0, gcs = 0, images = 0;
			int paths = 0, patterns = 0, regions = 0, textLayouts = 0, transforms = 0;
			for (Object object : objects) {
				if (object != null) {
					objectCount++;
					if (object instanceof Color) colors++;
					if (object instanceof Cursor) cursors++;
					if (object instanceof Font) fonts++;
					if (object instanceof GC) gcs++;
					if (object instanceof Image) images++;
					if (object instanceof Path) paths++;
					if (object instanceof Pattern) patterns++;
					if (object instanceof Region) regions++;
					if (object instanceof TextLayout) textLayouts++;
					if (object instanceof Transform) transforms++;
				}
			}
			if (objectCount != 0) {
				String string = "Summary: ";
				if (colors != 0) string += colors + " Color(s), ";
				if (cursors != 0) string += cursors + " Cursor(s), ";
				if (fonts != 0) string += fonts + " Font(s), ";
				if (gcs != 0) string += gcs + " GC(s), ";
				if (images != 0) string += images + " Image(s), ";
				if (paths != 0) string += paths + " Path(s), ";
				if (patterns != 0) string += patterns + " Pattern(s), ";
				if (regions != 0) string += regions + " Region(s), ";
				if (textLayouts != 0) string += textLayouts + " TextLayout(s), ";
				if (transforms != 0) string += transforms + " Transforms(s), ";
				if (string.length () != 0) {
					string = string.substring (0, string.length () - 2);
					System.err.println (string);
				}
				for (Error error : errors) {
					if (error != null) error.printStackTrace (System.err);
				}
			}
		}
	}
}

/**
 * Releases any internal resources back to the operating
 * system and clears all fields except the device handle.
 * <p>
 * When a device is destroyed, resources that were acquired
 * on behalf of the programmer need to be returned to the
 * operating system.  For example, if the device allocated a
 * font to be used as the system font, this font would be
 * freed in <code>release</code>.  Also,to assist the garbage
 * collector and minimize the amount of memory that is not
 * reclaimed when the programmer keeps a reference to a
 * disposed device, all fields except the handle are zero'd.
 * The handle is needed by <code>destroy</code>.
 * </p>
 * This method is called before <code>destroy</code>.
 * <p>
 * If subclasses reimplement this method, they must
 * call the <code>super</code> implementation.
 * </p>
 *
 * @see #dispose
 * @see #destroy
 */
protected void release () {
	if (gdipToken != null) {
		if (fontCollection != 0) {
			Gdip.PrivateFontCollection_delete(fontCollection);
		}
		fontCollection = 0;
		Gdip.GdiplusShutdown (gdipToken[0]);
	}
	SWTFontProvider.disposeFontRegistry(this);
	resourcesWithZoomSupport.clear();
	resourcesWithZoomSupport = null;
	gdipToken = null;
	scripts = null;
	logFonts = null;
	nFonts = 0;
}

/**
 * If the underlying window system supports printing warning messages
 * to the console, setting warnings to <code>false</code> prevents these
 * messages from being printed. If the argument is <code>true</code> then
 * message printing is not blocked.
 *
 * @param warnings <code>true</code>if warnings should be printed, and <code>false</code> otherwise
 *
 * @exception SWTException <ul>
 *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void setWarnings (boolean warnings) {
	checkDevice ();
}

/**
 * Gets the scaling factor from the device and calculates the zoom level.
 * @return zoom in percentage
 *
 * @noreference This method is not intended to be referenced by clients.
 * @nooverride This method is not intended to be re-implemented or extended by clients.
 * @since 3.105
 */
protected int getDeviceZoom () {
	return DPIUtil.mapDPIToZoom ( _getDPIx ());
}

void registerResourceWithZoomSupport(Resource resource) {
	resourcesWithZoomSupport.add(new ResourceReference(resource));
}

void deregisterResourceWithZoomSupport(Resource resource) {
	resourcesWithZoomSupport.remove(new ResourceReference(resource));
}

/**
 * Destroys the handles of all the resources in the resource tracker by
 * identifying the zoom levels which is not valid for any monitor
 *
 * @noreference This method is not intended to be referenced by clients.
 */
public static void win32_destroyUnusedHandles(Display display) {
	Set<Integer> availableZoomLevels = new HashSet<>();
	for (Monitor monitor : display.getMonitors()) {
	    availableZoomLevels.add(DPIUtil.getZoomForAutoscaleProperty(monitor.getZoom()));
	}
	Set<ResourceReference> resources = ((Device) display).resourcesWithZoomSupport;
	Iterator<ResourceReference> iterator = resources.iterator();

	while (iterator.hasNext()) {
		ResourceReference ref = iterator.next();
		Resource resource = ref.get();
		if (resource == null) {
			iterator.remove(); // Clean up dead reference.
			continue;
		}
		resource.destroyHandlesExcept(availableZoomLevels);
	}
}

private static class ResourceReference extends WeakReference<Resource> {

	public ResourceReference(Resource referent) {
		super(referent);
	}

	@Override
	public boolean equals(Object obj) {
		if(this == obj) return true;
		if (!(obj instanceof ResourceReference passedResource)) return false;
		return Objects.equals(this.get(), passedResource.get());
	}

	@Override
	public int hashCode() {
		Resource resource = this.get();
		return resource != null ? resource.hashCode() : 0;
	}
}
}
