Java tutorial
/******************************************************************************* * Copyright (c) 2002, 2012 Innoopract Informationssysteme GmbH 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: * Innoopract Informationssysteme GmbH - initial API and implementation * EclipseSource - ongoing development ******************************************************************************/ package org.eclipse.swt.graphics; import org.eclipse.swt.SWT; import org.eclipse.swt.internal.SerializableCompatibility; /** * Instances of this class describe fonts. * <p> * Application code does <em>not</em> need to explicitly release the * resources managed by each instance when those instances are no longer * required, and thus no <code>dispose()</code> method is provided. * * @see Font * @since 1.0 */ public final class FontData implements SerializableCompatibility { private String name; private int height; private int style; private String locale; /** * Constructs a new uninitialized font data. * @since 1.4 */ public FontData() { this("", 12, SWT.NORMAL); } /** * Constructs a new font data given a font name, * the height of the desired font in points, * and a font style. * * @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 - when the font name is null</li> * <li>ERROR_INVALID_ARGUMENT - if the height is negative</li> * </ul> */ public FontData(String name, int height, int style) { if (name == null) { SWT.error(SWT.ERROR_NULL_ARGUMENT); } if (height < 0) { SWT.error(SWT.ERROR_INVALID_ARGUMENT); } this.name = name; this.height = height; this.style = checkFontStyle(style); this.locale = ""; } /** * Constructs a new FontData given a string representation * in the form generated by the <code>FontData.toString</code> * method. * <!-- * <p> * Note that the representation varies between platforms, * and a FontData can only be created from a string that was * generated on the same platform. * </p> * --> * * @param string the string representation of a <code>FontData</code> (must not be null) * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the argument is null</li> * <li>ERROR_INVALID_ARGUMENT - if the argument does not represent a valid description</li> * </ul> * * @see #toString */ public FontData(String string) { if (string == null) { SWT.error(SWT.ERROR_NULL_ARGUMENT); } int start = 0; int end = string.indexOf('|'); if (end == -1) { SWT.error(SWT.ERROR_INVALID_ARGUMENT); } String version1 = string.substring(start, end); try { if (Integer.parseInt(version1) != 1) { SWT.error(SWT.ERROR_INVALID_ARGUMENT); } } catch (NumberFormatException e) { SWT.error(SWT.ERROR_INVALID_ARGUMENT); } start = end + 1; end = string.indexOf('|', start); if (end == -1) { SWT.error(SWT.ERROR_INVALID_ARGUMENT); } String name = string.substring(start, end); start = end + 1; end = string.indexOf('|', start); if (end == -1) { SWT.error(SWT.ERROR_INVALID_ARGUMENT); } int height = 0; try { height = Integer.parseInt(string.substring(start, end)); } catch (NumberFormatException e) { SWT.error(SWT.ERROR_INVALID_ARGUMENT); } start = end + 1; end = string.indexOf('|', start); if (end == -1) { SWT.error(SWT.ERROR_INVALID_ARGUMENT); } int style = 0; try { style = Integer.parseInt(string.substring(start, end)); } catch (NumberFormatException e) { SWT.error(SWT.ERROR_INVALID_ARGUMENT); } start = end + 1; end = string.indexOf('|', start); this.name = name; this.height = height; this.style = style; this.locale = ""; } /** * Returns a string representation of the receiver which is suitable for * constructing an equivalent instance using the <code>FontData(String)</code> * constructor. * * @return a string representation of the FontData */ public String toString() { StringBuilder buffer = new StringBuilder(); buffer.append("1|"); //$NON-NLS-1$ buffer.append(getName()); buffer.append("|"); //$NON-NLS-1$ buffer.append(getHeight()); buffer.append("|"); //$NON-NLS-1$ buffer.append(getStyle()); buffer.append("|"); //$NON-NLS-1$ return buffer.toString(); } /** * Returns the height of the receiver in points. * * @return the height of this FontData * @see #setHeight(int) */ public int getHeight() { return height; } /** * Returns the name of the receiver. * * @return the name of this <code>FontData</code> * @see #setName */ public String getName() { return name; } /** * Returns the style of the receiver which is a bitwise OR of * one or more of the <code>SWT</code> constants NORMAL, BOLD * and ITALIC. * * @return the style of this <code>FontData</code> * @see #setStyle */ public int getStyle() { return style; } /** * Returns the locale of the receiver. * <p> * The locale determines which platform character set this * font is going to use. Widgets and graphics operations that * use this font will convert UNICODE strings to the platform * character set of the specified locale. * </p> * <p> * On platforms where there are multiple character sets for a * given language/country locale, the variant portion of the * locale will determine the character set. * </p> * * @return the <code>String</code> representing a Locale object * @since 1.3 */ public String getLocale() { return locale; } /** * Sets the height of the receiver. The parameter is * specified in terms of points, where a point is one * seventy-second of an inch. * * @param height the height of the <code>FontData</code> * * @exception IllegalArgumentException <ul> * <li>ERROR_INVALID_ARGUMENT - if the height is negative</li> * </ul> * * @see #getHeight * @since 1.4 */ public void setHeight(int height) { if (height < 0) { SWT.error(SWT.ERROR_INVALID_ARGUMENT); } this.height = height; } /** * Sets the name of the receiver. * * @param name the name of the font data (must not be null) * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - when the font name is null</li> * </ul> * * @see #getName * @since 1.4 */ public void setName(String name) { if (name == null) { SWT.error(SWT.ERROR_NULL_ARGUMENT); } this.name = name; } /** * Sets the style of the receiver to the argument which must * be a bitwise OR of one or more of the <code>SWT</code> * constants NORMAL, BOLD and ITALIC. All other style bits are * ignored. * * @param style the new style for this <code>FontData</code> * * @see #getStyle * @since 1.4 */ public void setStyle(int style) { this.style = style; } /** * Sets the locale of the receiver. * <p> * The locale determines which platform character set this * font is going to use. Widgets and graphics operations that * use this font will convert UNICODE strings to the platform * character set of the specified locale. * </p> * <p> * On platforms where there are multiple character sets for a * given language/country locale, the variant portion of the * locale will determine the character set. * </p> * * @param locale the <code>String</code> representing a Locale object * @see java.util.Locale#toString * @since 1.4 */ public void setLocale(String locale) { String result = ""; if (locale != null) { int length = locale.length(); if (length > 0) { char sep = '_'; result = locale; for (int i = 0; i < 2; i++) { if (length > 0 && result.charAt(0) == sep) { result = result.substring(1); length -= 1; } } if (length > 0 && result.charAt(length - 1) == sep) { result = result.substring(0, length - 1); } } } this.locale = result; } /** * Compares the argument to the receiver, and returns true * if they represent the <em>same</em> object using a class * specific comparison. * * @param obj 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 obj) { boolean result = false; if (obj instanceof FontData) { FontData toCompare = (FontData) obj; // name can never be null result = name.equals(toCompare.name) && height == toCompare.height && style == toCompare.style; } return result; } /** * 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 name.hashCode() ^ height << 8 ^ style; } private static int checkFontStyle(int style) { int result = SWT.NORMAL; if ((style & SWT.BOLD) != 0) { result |= SWT.BOLD; } if ((style & SWT.ITALIC) != 0) { result |= SWT.ITALIC; } return result; } }