sun/awt/XSettings.java

	XSettings.java revision 2362
0N/A/*
0N/A * Copyright (c) 2003, 2004, Oracle and/or its affiliates. All rights reserved.
0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
0N/A *
0N/A * This code is free software; you can redistribute it and/or modify it
0N/A * under the terms of the GNU General Public License version 2 only, as
0N/A * published by the Free Software Foundation.  Oracle designates this
0N/A * particular file as subject to the "Classpath" exception as provided
0N/A * by Oracle in the LICENSE file that accompanied this code.
0N/A *
0N/A * This code is distributed in the hope that it will be useful, but WITHOUT
0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
0N/A * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
0N/A * version 2 for more details (a copy is included in the LICENSE file that
0N/A * accompanied this code).
0N/A *
0N/A * You should have received a copy of the GNU General Public License version
0N/A * 2 along with this work; if not, write to the Free Software Foundation,
0N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
0N/A *
0N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
0N/A * or visit www.oracle.com if you need additional information or have any
0N/A * questions.
0N/A */
0N/A
0N/Apackage sun.awt;
0N/A
0N/Aimport java.awt.Color;
0N/A
0N/Aimport java.io.UnsupportedEncodingException;
0N/A
0N/Aimport java.util.HashMap;
0N/Aimport java.util.Map;
0N/A
0N/A
0N/A/**
0N/A * Per-screen XSETTINGS.
0N/A */
0N/Apublic class XSettings {
0N/A
0N/A    /**
0N/A     */
0N/A    private long serial = -1;
0N/A
0N/A
0N/A    /**
0N/A     * Update these settings with <code>data</code> obtained from
0N/A     * XSETTINGS manager.
0N/A     *
0N/A     * @param data settings data obtained from
0N/A     *     <code>_XSETTINGS_SETTINGS</code> window property of the
0N/A     *     settings manager.
0N/A     * @return a <code>Map</code> of changed settings.
0N/A     */
0N/A    public Map update(byte[] data) {
0N/A        return (new Update(data)).update();
0N/A    }
0N/A
0N/A
0N/A    /**
0N/A     * TBS ...
0N/A     */
0N/A    class Update {
0N/A
0N/A        /* byte order mark */
0N/A        private static final int LITTLE_ENDIAN = 0;
0N/A        private static final int BIG_ENDIAN    = 1;
0N/A
0N/A        /* setting type */
0N/A        private static final int TYPE_INTEGER = 0;
0N/A        private static final int TYPE_STRING  = 1;
0N/A        private static final int TYPE_COLOR   = 2;
0N/A
0N/A        private byte[] data;
0N/A        private int dlen;
0N/A        private int idx;
0N/A        private boolean isLittle;
0N/A        private long serial = -1;
0N/A        private int nsettings = 0;
0N/A        private boolean isValid;
0N/A
0N/A        private HashMap updatedSettings;
0N/A
0N/A
0N/A        /**
0N/A         * Construct an Update object for the data read from
0N/A         * <code>_XSETTINGS_SETTINGS</code> property of the XSETTINGS
0N/A         * selection owner.
0N/A         *
0N/A         * @param data <code>_XSETTINGS_SETTINGS</code> contents.
0N/A         */
0N/A        Update(byte[] data) {
0N/A            this.data = data;
0N/A
0N/A            dlen = data.length;
0N/A            if (dlen < 12) {
0N/A                // XXX: debug trace?
0N/A                return;
0N/A            }
0N/A
0N/A            // first byte gives endianness of the data
0N/A            // next 3 bytes are unused (pad to 32 bit)
0N/A            idx = 0;
0N/A            isLittle = (getCARD8() == LITTLE_ENDIAN);
0N/A
0N/A            idx = 4;
0N/A            serial = getCARD32();
0N/A
0N/A            // N_SETTINGS is actually CARD32 (i.e. unsigned), but
0N/A            // since java doesn't have an unsigned int type, and
0N/A            // N_SETTINGS cannot realistically exceed 2^31 (so we
0N/A            // gonna use int anyway), just read it as INT32.
0N/A            idx = 8;
0N/A            nsettings = getINT32();
0N/A
0N/A            updatedSettings = new HashMap();
0N/A
0N/A            isValid = true;
0N/A        }
0N/A
0N/A
0N/A        private void needBytes(int n)
0N/A            throws IndexOutOfBoundsException
0N/A        {
0N/A            if (idx + n <= dlen) {
0N/A                return;
0N/A            }
0N/A
0N/A            throw new IndexOutOfBoundsException("at " + idx
0N/A                                                + " need " + n
0N/A                                                + " length " + dlen);
0N/A        }
0N/A
0N/A
0N/A        private int getCARD8()
0N/A            throws IndexOutOfBoundsException
0N/A        {
0N/A            needBytes(1);
0N/A
0N/A            int val = data[idx] & 0xff;
0N/A
0N/A            ++idx;
0N/A            return val;
0N/A        }
0N/A
0N/A
0N/A        private int getCARD16()
0N/A            throws IndexOutOfBoundsException
0N/A        {
0N/A            needBytes(2);
0N/A
0N/A            int val;
0N/A            if (isLittle) {
0N/A                val = ((data[idx + 0] & 0xff)      )
0N/A                    | ((data[idx + 1] & 0xff) <<  8);
0N/A            } else {
0N/A                val = ((data[idx + 0] & 0xff) <<  8)
0N/A                    | ((data[idx + 1] & 0xff)      );
0N/A            }
0N/A
0N/A            idx += 2;
0N/A            return val;
0N/A        }
0N/A
0N/A
0N/A        private int getINT32()
0N/A            throws IndexOutOfBoundsException
0N/A        {
0N/A            needBytes(4);
0N/A
0N/A            int val;
0N/A            if (isLittle) {
0N/A                val = ((data[idx + 0] & 0xff)      )
0N/A                    | ((data[idx + 1] & 0xff) <<  8)
0N/A                    | ((data[idx + 2] & 0xff) << 16)
0N/A                    | ((data[idx + 3] & 0xff) << 24);
0N/A            } else {
                val = ((data[idx + 0] & 0xff) << 24)
                    | ((data[idx + 1] & 0xff) << 16)
                    | ((data[idx + 2] & 0xff) <<  8)
                    | ((data[idx + 3] & 0xff) <<  0);
            }

            idx += 4;
            return val;
        }


        private long getCARD32()
            throws IndexOutOfBoundsException
        {
            return getINT32() & 0x00000000ffffffffL;
        }


        private String getString(int len)
            throws IndexOutOfBoundsException
        {
            needBytes(len);

            String str = null;
            try {
                str = new String(data, idx, len, "UTF-8");
            } catch (UnsupportedEncodingException e) {
                // XXX: cannot happen, "UTF-8" is always supported
            }

            idx = (idx + len + 3) & ~0x3;
            return str;
        }


        /**
         * Update settings.
         */
        public Map update() {
            if (!isValid) {
                return null;
            }

            synchronized (XSettings.this) {
                long currentSerial = XSettings.this.serial;

                if (this.serial <= currentSerial) {
                    return null;
                }

                for (int i = 0; i < nsettings && idx < dlen; ++i) {
                    updateOne(currentSerial);
                }

                XSettings.this.serial = this.serial;
            }

            return updatedSettings;
        }


        /**
         * Parses a particular x setting.
         *
         * @exception IndexOutOfBoundsException if there isn't enough
         *     data for a setting.
         */
        private void updateOne(long currentSerial)
            throws IndexOutOfBoundsException,
                   IllegalArgumentException
        {
            int type = getCARD8();
            ++idx;              // pad to next CARD16

            // save position of the property name, skip to serial
            int nameLen = getCARD16();
            int nameIdx = idx;

            // check if we should bother
            idx = (idx + nameLen + 3) & ~0x3; // pad to 32 bit
            long lastChanged = getCARD32();

            // Avoid constructing garbage for properties that has not
            // changed, skip the data for this property.
            if (lastChanged <= currentSerial) { // skip
                if (type == TYPE_INTEGER) {
                    idx += 4;
                } else if (type == TYPE_STRING) {
                    int len = getINT32();
                    idx = (idx + len + 3) & ~0x3;
                } else if (type == TYPE_COLOR) {
                    idx += 8;   // 4 CARD16
                } else {
                    throw new IllegalArgumentException("Unknown type: "
                                                       + type);
                }

                return;
            }

            idx = nameIdx;
            String name = getString(nameLen);
            idx += 4;           // skip serial, parsed above

            Object value = null;
            if (type == TYPE_INTEGER) {
                value = Integer.valueOf(getINT32());
            }
            else if (type == TYPE_STRING) {
                value = getString(getINT32());
            }
            else if (type == TYPE_COLOR) {
                int r = getCARD16();
                int g = getCARD16();
                int b = getCARD16();
                int a = getCARD16();

                value = new Color(r / 65535.0f,
                                  g / 65535.0f,
                                  b / 65535.0f,
                                  a / 65535.0f);
            }
            else {
                throw new IllegalArgumentException("Unknown type: " + type);
            }

            if (name == null) {
                // dtrace???
                return;
            }

            updatedSettings.put(name, value);
        }

    } // class XSettings.Update
}