Java tutorial
/* * Copyright (c) 1996, 2018, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.awt; import java.beans.ConstructorProperties; import java.io.InputStream; import java.security.AccessController; import java.security.PrivilegedAction; import java.security.PrivilegedExceptionAction; import java.util.Hashtable; import java.util.Properties; import java.util.StringTokenizer; import sun.awt.AWTAccessor; import sun.util.logging.PlatformLogger; /** * A class to encapsulate the bitmap representation of the mouse cursor. * * @see Component#setCursor * @author Amy Fowler */ public class Cursor implements java.io.Serializable { /** * The default cursor type (gets set if no cursor is defined). */ public static final int DEFAULT_CURSOR = 0; /** * The crosshair cursor type. */ public static final int CROSSHAIR_CURSOR = 1; /** * The text cursor type. */ public static final int TEXT_CURSOR = 2; /** * The wait cursor type. */ public static final int WAIT_CURSOR = 3; /** * The south-west-resize cursor type. */ public static final int SW_RESIZE_CURSOR = 4; /** * The south-east-resize cursor type. */ public static final int SE_RESIZE_CURSOR = 5; /** * The north-west-resize cursor type. */ public static final int NW_RESIZE_CURSOR = 6; /** * The north-east-resize cursor type. */ public static final int NE_RESIZE_CURSOR = 7; /** * The north-resize cursor type. */ public static final int N_RESIZE_CURSOR = 8; /** * The south-resize cursor type. */ public static final int S_RESIZE_CURSOR = 9; /** * The west-resize cursor type. */ public static final int W_RESIZE_CURSOR = 10; /** * The east-resize cursor type. */ public static final int E_RESIZE_CURSOR = 11; /** * The hand cursor type. */ public static final int HAND_CURSOR = 12; /** * The move cursor type. */ public static final int MOVE_CURSOR = 13; /** * @deprecated As of JDK version 1.7, the {@link #getPredefinedCursor(int)} * method should be used instead. */ @Deprecated protected static Cursor[] predefined = new Cursor[14]; /** * This field is a private replacement for 'predefined' array. */ private static final Cursor[] predefinedPrivate = new Cursor[14]; /* Localization names and default values */ static final String[][] cursorProperties = { { "AWT.DefaultCursor", "Default Cursor" }, { "AWT.CrosshairCursor", "Crosshair Cursor" }, { "AWT.TextCursor", "Text Cursor" }, { "AWT.WaitCursor", "Wait Cursor" }, { "AWT.SWResizeCursor", "Southwest Resize Cursor" }, { "AWT.SEResizeCursor", "Southeast Resize Cursor" }, { "AWT.NWResizeCursor", "Northwest Resize Cursor" }, { "AWT.NEResizeCursor", "Northeast Resize Cursor" }, { "AWT.NResizeCursor", "North Resize Cursor" }, { "AWT.SResizeCursor", "South Resize Cursor" }, { "AWT.WResizeCursor", "West Resize Cursor" }, { "AWT.EResizeCursor", "East Resize Cursor" }, { "AWT.HandCursor", "Hand Cursor" }, { "AWT.MoveCursor", "Move Cursor" }, }; /** * The chosen cursor type initially set to * the {@code DEFAULT_CURSOR}. * * @serial * @see #getType() */ int type = DEFAULT_CURSOR; /** * The type associated with all custom cursors. */ public static final int CUSTOM_CURSOR = -1; /* * hashtable, resource prefix, filename, and properties for custom cursors * support */ private static final Hashtable<String, Cursor> systemCustomCursors = new Hashtable<>(1); private static final String RESOURCE_PREFIX = "/sun/awt/resources/cursors/"; private static final String PROPERTIES_FILE = RESOURCE_PREFIX + "cursors.properties"; private static Properties systemCustomCursorProperties = null; private static final String CURSOR_DOT_PREFIX = "Cursor."; private static final String DOT_FILE_SUFFIX = ".File"; private static final String DOT_HOTSPOT_SUFFIX = ".HotSpot"; private static final String DOT_NAME_SUFFIX = ".Name"; /* * JDK 1.1 serialVersionUID */ private static final long serialVersionUID = 8028237497568985504L; private static final PlatformLogger log = PlatformLogger.getLogger("java.awt.Cursor"); static { /* ensure that the necessary native libraries are loaded */ Toolkit.loadLibraries(); if (!GraphicsEnvironment.isHeadless()) { initIDs(); } AWTAccessor.setCursorAccessor(new AWTAccessor.CursorAccessor() { public long getPData(Cursor cursor) { return cursor.pData; } public void setPData(Cursor cursor, long pData) { cursor.pData = pData; } public int getType(Cursor cursor) { return cursor.type; } }); } /** * Initialize JNI field and method IDs for fields that may be * accessed from C. */ private static native void initIDs(); /** * Hook into native data. */ private transient long pData; private transient Object anchor = new Object(); static class CursorDisposer implements sun.java2d.DisposerRecord { volatile long pData; public CursorDisposer(long pData) { this.pData = pData; } public void dispose() { if (pData != 0) { finalizeImpl(pData); } } } transient CursorDisposer disposer; private void setPData(long pData) { this.pData = pData; if (GraphicsEnvironment.isHeadless()) { return; } if (disposer == null) { disposer = new CursorDisposer(pData); // anchor is null after deserialization if (anchor == null) { anchor = new Object(); } sun.java2d.Disposer.addRecord(anchor, disposer); } else { disposer.pData = pData; } } /** * The user-visible name of the cursor. * * @serial * @see #getName() */ protected String name; /** * Returns a cursor object with the specified predefined type. * * @param type the type of predefined cursor * @return the specified predefined cursor * @throws IllegalArgumentException if the specified cursor type is * invalid */ public static Cursor getPredefinedCursor(int type) { if (type < Cursor.DEFAULT_CURSOR || type > Cursor.MOVE_CURSOR) { throw new IllegalArgumentException("illegal cursor type"); } Cursor c = predefinedPrivate[type]; if (c == null) { predefinedPrivate[type] = c = new Cursor(type); } // fill 'predefined' array for backwards compatibility. if (predefined[type] == null) { predefined[type] = c; } return c; } /** * Returns a system-specific custom cursor object matching the * specified name. Cursor names are, for example: "Invalid.16x16" * * @param name a string describing the desired system-specific custom cursor * @return the system specific custom cursor named * @exception HeadlessException if * {@code GraphicsEnvironment.isHeadless} returns true * @exception AWTException in case of erroneous retrieving of the cursor */ public static Cursor getSystemCustomCursor(final String name) throws AWTException, HeadlessException { GraphicsEnvironment.checkHeadless(); Cursor cursor = systemCustomCursors.get(name); if (cursor == null) { synchronized (systemCustomCursors) { if (systemCustomCursorProperties == null) loadSystemCustomCursorProperties(); } String prefix = CURSOR_DOT_PREFIX + name; String key = prefix + DOT_FILE_SUFFIX; if (!systemCustomCursorProperties.containsKey(key)) { if (log.isLoggable(PlatformLogger.Level.FINER)) { log.finer("Cursor.getSystemCustomCursor(" + name + ") returned null"); } return null; } final String fileName = systemCustomCursorProperties.getProperty(key); final String localized = systemCustomCursorProperties.getProperty(prefix + DOT_NAME_SUFFIX, name); String hotspot = systemCustomCursorProperties.getProperty(prefix + DOT_HOTSPOT_SUFFIX); if (hotspot == null) throw new AWTException("no hotspot property defined for cursor: " + name); StringTokenizer st = new StringTokenizer(hotspot, ","); if (st.countTokens() != 2) throw new AWTException("failed to parse hotspot property for cursor: " + name); final Point hotPoint; try { hotPoint = new Point(Integer.parseInt(st.nextToken()), Integer.parseInt(st.nextToken())); } catch (NumberFormatException nfe) { throw new AWTException("failed to parse hotspot property for cursor: " + name); } final Toolkit toolkit = Toolkit.getDefaultToolkit(); final String file = RESOURCE_PREFIX + fileName; final InputStream in = AccessController.doPrivileged((PrivilegedAction<InputStream>) () -> { return Cursor.class.getResourceAsStream(file); }); try (in) { Image image = toolkit.createImage(in.readAllBytes()); cursor = toolkit.createCustomCursor(image, hotPoint, localized); } catch (Exception e) { throw new AWTException("Exception: " + e.getClass() + " " + e.getMessage() + " occurred while creating cursor " + name); } if (cursor == null) { if (log.isLoggable(PlatformLogger.Level.FINER)) { log.finer("Cursor.getSystemCustomCursor(" + name + ") returned null"); } } else { systemCustomCursors.put(name, cursor); } } return cursor; } /** * Return the system default cursor. * * @return the default cursor */ public static Cursor getDefaultCursor() { return getPredefinedCursor(Cursor.DEFAULT_CURSOR); } /** * Creates a new cursor object with the specified type. * @param type the type of cursor * @throws IllegalArgumentException if the specified cursor type * is invalid */ @ConstructorProperties({ "type" }) public Cursor(int type) { if (type < Cursor.DEFAULT_CURSOR || type > Cursor.MOVE_CURSOR) { throw new IllegalArgumentException("illegal cursor type"); } this.type = type; // Lookup localized name. name = Toolkit.getProperty(cursorProperties[type][0], cursorProperties[type][1]); } /** * Creates a new custom cursor object with the specified name.<p> * Note: this constructor should only be used by AWT implementations * as part of their support for custom cursors. Applications should * use Toolkit.createCustomCursor(). * @param name the user-visible name of the cursor. * @see java.awt.Toolkit#createCustomCursor */ protected Cursor(String name) { this.type = Cursor.CUSTOM_CURSOR; this.name = name; } /** * Returns the type for this cursor. * * @return the cursor type */ public int getType() { return type; } /** * Returns the name of this cursor. * @return a localized description of this cursor. * @since 1.2 */ public String getName() { return name; } /** * Returns a string representation of this cursor. * @return a string representation of this cursor. * @since 1.2 */ public String toString() { return getClass().getName() + "[" + getName() + "]"; } /* * load the cursor.properties file */ private static void loadSystemCustomCursorProperties() throws AWTException { synchronized (systemCustomCursors) { systemCustomCursorProperties = new Properties(); try { AccessController.doPrivileged((PrivilegedExceptionAction<Object>) () -> { try (InputStream is = Cursor.class.getResourceAsStream(PROPERTIES_FILE)) { systemCustomCursorProperties.load(is); } return null; }); } catch (Exception e) { systemCustomCursorProperties = null; throw new AWTException("Exception: " + e.getClass() + " " + e.getMessage() + " occurred while loading: " + PROPERTIES_FILE); } } } private static native void finalizeImpl(long pData); }