/*******************************************************************************
 * Copyright (c) 2000, 2008 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.graphics;


import org.eclipse.swt.internal.*;
import org.eclipse.swt.internal.motif.*;
import org.eclipse.swt.*;

/**
 * Instances of this class manage operating system resources that
 * define how text looks when it is displayed. Fonts may be constructed
 * by providing a device and either name, size and style information
 * or a <code>FontData</code> object which encapsulates this data.
 * <p>
 * Application code must explicitly invoke the <code>Font.dispose()</code> 
 * method to release the operating system resources managed by each instance
 * when those instances are no longer required.
 * </p>
 *
 * @see FontData
 * @see <a href="http://www.eclipse.org/swt/snippets/#font">Font snippets</a>
 * @see <a href="http://www.eclipse.org/swt/examples.php">SWT Examples: GraphicsExample, PaintExample</a>
 * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
 */
public final class Font extends Resource {
	/**
	 * the handle to the OS font resource
	 * (Warning: This field is platform dependent)
	 * <p>
	 * <b>IMPORTANT:</b> This field is <em>not</em> part of the SWT
	 * public API. 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 accessed from application code.
	 * </p>
	 * 
	 * @noreference This field is not intended to be referenced by clients.
	 */
	public int handle;

	/**
	 * the code page of the font
	 * (Warning: This field is platform dependent)
	 * <p>
	 * <b>IMPORTANT:</b> This field is <em>not</em> part of the SWT
	 * public API. 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 accessed from application code.
	 * </p>
	 * 
	 * @noreference This field is not intended to be referenced by clients.
	 * 
	 * @since 2.0
	 */
	public String codePage;

Font (Device device) {
	super(device);
}

/**	 
 * Constructs a new font given a device and font data
 * which describes the desired font's appearance.
 * <p>
 * You must dispose the font when it is no longer required. 
 * </p>
 *
 * @param device the device to create the font on
 * @param fd the FontData that describes the desired font (must not be null)
 * 
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device</li>
 *    <li>ERROR_NULL_ARGUMENT - if the fd argument is null</li>
 * </ul>
 * @exception SWTError <ul>
 *    <li>ERROR_NO_HANDLES - if a font could not be created from the given font data</li>
 * </ul>
 */
public Font (Device device, FontData fd) {
	super(device);
	if (fd == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	init(new FontData[] {fd});
	init();
}

/**	 
 * Constructs a new font given a device and an array
 * of font data which describes the desired font's
 * appearance.
 * <p>
 * You must dispose the font when it is no longer required. 
 * </p>
 *
 * @param device the device to create the font on
 * @param fds the array of FontData that describes the desired font (must not be null)
 * 
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device</li>
 *    <li>ERROR_NULL_ARGUMENT - if the fds argument is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the length of fds is zero</li>
 *    <li>ERROR_NULL_ARGUMENT - if any fd in the array is null</li>
 * </ul>
 * @exception SWTError <ul>
 *    <li>ERROR_NO_HANDLES - if a font could not be created from the given font data</li>
 * </ul>
 * 
 * @since 2.1
 */
public Font (Device device, FontData[] fds) {
	super(device);
	if (fds == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	if (fds.length == 0) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	for (int i=0; i<fds.length; i++) {
		if (fds[i] == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	}
	init(fds);
	init();
}

/**	 
 * Constructs a new font given a device, a font name,
 * the height of the desired font in points, and a font
 * style.
 * <p>
 * You must dispose the font when it is no longer required. 
 * </p>
 *
 * @param device the device to create the font on
 * @param name the name of the font (must not be null)
 * @param height the font height in points
 * @param style a bit or combination of NORMAL, BOLD, ITALIC
 * 
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device</li>
 *    <li>ERROR_NULL_ARGUMENT - if the name argument is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the height is negative</li>
 * </ul>
 * @exception SWTError <ul>
 *    <li>ERROR_NO_HANDLES - if a font could not be created from the given arguments</li>
 * </ul>
 */
public Font (Device device, String name, int height, int style) {
	super(device);
	if (name == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	init(new FontData[]{new FontData(name, height, style)});
	init();
}

/*public*/ Font (Device device, String name, float height, int style) {
	super(device);
	if (name == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	init(new FontData[]{new FontData(name, height, style)});
	init();
}

void destroy() {
	if (handle == device.systemFont.handle) return;
	OS.XmFontListFree (handle);
	handle = 0;
}

/**
 * Compares the argument to the receiver, and returns true
 * if they represent the <em>same</em> object using a class
 * specific comparison.
 *
 * @param object the object to compare with this object
 * @return <code>true</code> if the object is the same as this object and <code>false</code> otherwise
 *
 * @see #hashCode
 */
public boolean equals (Object object) {
	if (object == this) return true;
	if (!(object instanceof Font)) return false;
	Font font = (Font)object;
	return device == font.device && handle == font.handle;
}

/**
 * Returns the code page for the specified font list.
 *
 * @return the code page for the font list
 */
static String getCodePage (int xDisplay, int fontList) {
	int[] buffer = new int[1];
	if (!OS.XmFontListInitFontContext(buffer, fontList)) return null;
	int context = buffer[0];
	XFontStruct fontStruct = new XFontStruct();
	int fontListEntry;
	String codePage = null;
	/* Go through each entry in the font list */
	while ((fontListEntry = OS.XmFontListNextEntry(context)) != 0) {
		int fontPtr = OS.XmFontListEntryGetFont(fontListEntry, buffer);
		if (buffer[0] == OS.XmFONT_IS_FONT) { 
			/* FontList contains a single font */
			OS.memmove(fontStruct,fontPtr,20 * 4);
			int propPtr = fontStruct.properties;
			for (int i = 0; i < fontStruct.n_properties; i++) {
				/* Look through properties for XAFONT */
				int[] prop = new int[2];
				OS.memmove(prop, propPtr, 8);
				if (prop[0] == OS.XA_FONT) {
					/* Found it, prop[1] points to the string */
					int ptr = OS.XmGetAtomName(xDisplay, prop[1]);
					int length = OS.strlen(ptr);
					byte[] nameBuf = new byte[length];
					OS.memmove(nameBuf, ptr, length);
					/* Use the character encoding for the default locale */
					String xlfd = new String(Converter.mbcsToWcs(null, nameBuf)).toLowerCase();
					int start = xlfd.lastIndexOf ('-');
					if (start != -1 && start > 0) {
						start = xlfd.lastIndexOf ('-', start - 1);
						if (start != -1) {
							codePage = xlfd.substring (start + 1, xlfd.length ());
							if (codePage.indexOf ("iso") == 0) {
								if (OS.IsLinux) {
									codePage = "ISO-" + codePage.substring (3, codePage.length ());
								}
								if (OS.IsAIX) {
									codePage = "ISO" + codePage.substring (3, codePage.length ());
								}
								if (OS.IsHPUX) {	
									start = codePage.lastIndexOf('-');
									if (start != -1) {
										codePage = codePage.substring (0, start) + codePage.substring (start + 1, codePage.length ());
									}
								}
							}
						}
					}
					OS.XtFree(ptr);
					break;
				}
				propPtr += 8;
			}
		}
		else { 
			/* FontList contains a fontSet */
			
			/* Get the font set locale */
			int localePtr = OS.XLocaleOfFontSet(fontPtr);
			int length = OS.strlen (localePtr);
			byte [] locale = new byte [length + 1];
			OS.memmove (locale, localePtr, length);
			
			/* Get code page for the font set locale */
			OS.setlocale (OS.LC_CTYPE,  locale);
			int codesetPtr = OS.nl_langinfo (OS.CODESET);
			length = OS.strlen (codesetPtr);
			byte [] codeset = new byte [length];
			OS.memmove (codeset, codesetPtr, length);
			codePage = new String(Converter.mbcsToWcs(null, codeset));
			
			/* Reset the locale */
			OS.setlocale (OS.LC_CTYPE, new byte[1]);
		}
	}
	OS.XmFontListFreeFontContext(context);
	return codePage;
}

/**
 * Returns an array of <code>FontData</code>s representing the receiver.
 * On Windows, only one FontData will be returned per font. On X however, 
 * a <code>Font</code> object <em>may</em> be composed of multiple X 
 * fonts. To support this case, we return an array of font data objects.
 *
 * @return an array of font data objects describing the receiver
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public FontData[] getFontData() {
	if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	int xDisplay = device.xDisplay;
	/*
	 * Create a font context to iterate over each element in the font list.
	 */
	int[] buffer = new int[1];
	if (!OS.XmFontListInitFontContext(buffer, handle)) {
		SWT.error (SWT.ERROR_INVALID_FONT);
	}
	int context = buffer[0];
	XFontStruct fontStruct = new XFontStruct();
	int fontListEntry;
	int[] fontStructPtr = new int[1];
	int[] fontNamePtr = new int[1];
	FontData[] data = new FontData[0];
	try {
		/* Go through each entry in the font list */
		while ((fontListEntry = OS.XmFontListNextEntry(context)) != 0) {
			int fontPtr = OS.XmFontListEntryGetFont(fontListEntry, buffer);
			if (buffer[0] == OS.XmFONT_IS_FONT) { 
				/* FontList contains a single font */
				OS.memmove(fontStruct,fontPtr,20 * 4);
				int propPtr = fontStruct.properties;
				for (int i = 0; i < fontStruct.n_properties; i++) {
					/* Look through properties for XAFONT */
					int[] prop = new int[2];
					OS.memmove(prop, propPtr, 8);
					if (prop[0] == OS.XA_FONT) {
						/* Found it, prop[1] points to the string */
						int ptr = OS.XmGetAtomName(xDisplay, prop[1]);
						int length = OS.strlen(ptr);
						byte[] nameBuf = new byte[length];
						OS.memmove(nameBuf, ptr, length);
						OS.XtFree(ptr);
						/* Use the character encoding for the default locale */
						String xlfd = new String(Converter.mbcsToWcs(null, nameBuf)).toLowerCase();
						/* Add the xlfd to the array */
						FontData[] newData = new FontData[data.length + 1];
						System.arraycopy(data, 0, newData, 0, data.length);
						newData[newData.length - 1] = FontData.motif_new(xlfd);
						data = newData;
						break;
					}
					propPtr += 8;
				}
			}
			else { 
				/* FontList contains a fontSet */
				int nFonts = OS.XFontsOfFontSet(fontPtr,fontStructPtr,fontNamePtr);
				int [] fontStructs = new int[nFonts];
				OS.memmove(fontStructs,fontStructPtr[0],nFonts * 4);
				for (int i = 0; i < nFonts; i++) { // Go through each fontStruct in the font set.
					OS.memmove(fontStruct,fontStructs[i],20 * 4);
					int propPtr = fontStruct.properties;
					for (int j = 0; j < fontStruct.n_properties; j++) {
						// Look through properties for XAFONT
						int[] prop = new int[2];
						OS.memmove(prop, propPtr, 8);
						if (prop[0] == OS.XA_FONT) {
							/* Found it, prop[1] points to the string */
							int ptr = OS.XmGetAtomName(xDisplay, prop[1]);
							int length = OS.strlen(ptr);
							byte[] nameBuf = new byte[length];
							OS.memmove(nameBuf, ptr, length);
							OS.XFree(ptr);
							String xlfd = new String(Converter.mbcsToWcs(null, nameBuf)).toLowerCase();
							/* Add the xlfd to the array */
							FontData[] newData = new FontData[data.length + 1];
							System.arraycopy(data, 0, newData, 0, data.length);
							try {
								newData[newData.length - 1] = FontData.motif_new(xlfd);
							} catch (Exception e) {
								/*
								 * Some font servers, for example, xfstt, do not pass
								 * reasonable font properties to the client, so we
								 * cannot construct a FontData for these. Try to use
								 * the font name instead.
								 */
								int[] fontName = new int[1];
								OS.memmove(fontName, fontNamePtr [0] + (i * 4), 4);
								ptr = fontName[0];
								if (ptr != 0) {
									length = OS.strlen(ptr);
									nameBuf = new byte[length];
									OS.memmove(nameBuf, ptr, length);
									xlfd = new String(Converter.mbcsToWcs(null, nameBuf)).toLowerCase();
									newData[newData.length - 1] = FontData.motif_new(xlfd);
								}
							}
							data = newData;
							break;
						}
						propPtr += 8;
					}
				}
			}
		}
		if (data.length == 0) SWT.error (SWT.ERROR_INVALID_FONT);
	} catch (Exception e) {
		/*
		 * Some font servers, for example, xfstt, do not pass
		 * reasonable font properties to the client, so we
		 * cannot construct a FontData for these.
		 */
		SWT.error (SWT.ERROR_INVALID_FONT);
	} finally {
		OS.XmFontListFreeFontContext(context);
	}
	return data;
}

/**
 * Returns an integer hash code for the receiver. Any two 
 * objects that return <code>true</code> when passed to 
 * <code>equals</code> must return the same value for this
 * method.
 *
 * @return the receiver's hash
 *
 * @see #equals
 */
public int hashCode () {
	return handle;
}

void init (FontData[] fds) {
	/* Change current locale if needed. Note: only the first font data is used */
	FontData firstFd = fds[0];
	if (firstFd.lang != null) {
		String lang = firstFd.lang;
		String country = firstFd.country;
		String variant = firstFd.variant;
		String osLocale = lang;
		if (country != null) osLocale += "_" + country;
		if (variant != null) osLocale += "." + variant;
		int length = osLocale.length();
		byte [] buffer = new byte[length + 1];
		for (int i=0; i<length; i++) {
			buffer[i] = (byte)osLocale.charAt(i);
		}
		OS.setlocale (OS.LC_CTYPE, buffer);
	}
	
	int fontType = OS.XmFONT_IS_FONTSET;
	/*
	* Bug in HPUX.  If the locale is "C" then FontSets do not work
	* properly.  The fix is to detect this case and use a Font struct
	* instead.
	*/
	if (OS.IsHPUX) {
		int localePtr = OS.setlocale(OS.LC_CTYPE, null);
		int length = OS.strlen(localePtr);
		byte[] buffer = new byte[length];
		OS.memmove(buffer, localePtr, length);
		if ("C".equals(new String(Converter.mbcsToWcs(null, buffer)))) {
			fontType = OS.XmFONT_IS_FONT;
		}
	}
	
	/* Generate desire font name */
	Point dpi = null;
	if (device.setDPI) dpi = device.getDPI();
	StringBuffer stringBuffer = new StringBuffer();
	for (int i = 0; i < fds.length; i++) {
		if (i != 0) stringBuffer.append(',');
		FontData fd = fds[i];
		int hRes = fd.horizontalResolution, vRes = fd.verticalResolution;
		if (dpi != null) {
			fd.horizontalResolution = dpi.x;
			fd.verticalResolution = dpi.y;
		}
		stringBuffer.append(fd.getXlfd());
		fd.horizontalResolution = hRes;
		fd.verticalResolution = vRes;
	}

	/* Append simplified font name */		
	FontData newFd = new FontData();
	newFd.points = firstFd.points;
	/*
	* Bug in Motif.  In Japanese AIX only, in some cases loading a bold Japanese
	* font takes a very long time (10 minutes) when there are no Japanese bold
	* fonts available.  The fix is to wildcard the field weight.
	*/
	if (fontType == OS.XmFONT_IS_FONTSET) {
		if (OS.IsAIX && OS.IsDBLocale) {
			stringBuffer.append(',');
			stringBuffer.append(newFd.getXlfd());
		} else {
			newFd.weight = firstFd.weight;
			newFd.slant = firstFd.slant;
			stringBuffer.append(',');
			stringBuffer.append(newFd.getXlfd());
			newFd.weight = null;
			newFd.slant = null;		
			stringBuffer.append(',');
			stringBuffer.append(newFd.getXlfd());
		}
	}
	
	/* Load font list entry */		 
	boolean warnings = device._getWarnings ();
	device._setWarnings (false);
	byte[] buffer = Converter.wcsToMbcs(null, stringBuffer.toString() , true);
	int fontListEntry = OS.XmFontListEntryLoad(device.xDisplay, buffer, fontType, OS.XmFONTLIST_DEFAULT_TAG);
	device._setWarnings (warnings);
	if (fontListEntry != 0) {
		handle = OS.XmFontListAppendEntry(0, fontListEntry);
		OS.XmFontListEntryFree(new int[]{fontListEntry});
		int codesetPtr = OS.nl_langinfo(OS.CODESET);
		int length = OS.strlen(codesetPtr);
		buffer = new byte[length];
		OS.memmove(buffer, codesetPtr, length);
		codePage = new String(Converter.mbcsToWcs(null, buffer));
	} else {
		Font systemFont = device.systemFont;
		handle = systemFont.handle;
		codePage = systemFont.codePage;
	}
	
	/* Reset current locale if needed */
	if (firstFd.lang != null) OS.setlocale(OS.LC_CTYPE, new byte[0]);

	if (handle == 0) SWT.error(SWT.ERROR_NO_HANDLES);
}

/**
 * Returns <code>true</code> if the font has been disposed,
 * and <code>false</code> otherwise.
 * <p>
 * This method gets the dispose state for the font.
 * When a font has been disposed, it is an error to
 * invoke any other method (except {@link #dispose()}) using the font.
 *
 * @return <code>true</code> when the font is disposed and <code>false</code> otherwise
 */
public boolean isDisposed() {
	return handle == 0;
}

public static Font motif_new(Device device, int handle) {
	Font font = new Font(device);
	font.handle = handle;
	font.codePage = getCodePage(device.xDisplay, handle);
	return font;
}

/**
 * Returns a string containing a concise, human-readable
 * description of the receiver.
 *
 * @return a string representation of the receiver
 */
public String toString () {
	if (isDisposed()) return "Font {*DISPOSED*}";
	return "Font {" + handle + "}";
}
}