registers.java

Linux下面最好用的程序、文本编辑工具之一。

		StringBuffer buf = new StringBuffer();
		for(int i = 0; i < registers.length; i++)
		{
			if(registers[i] != null)
			{
				if(buf.length() != 0)
					buf.append(' ');
				buf.append((char)i);
			}
		}

		if(buf.length() == 0)
			return jEdit.getProperty("view.status.no-registers");
		else
			return buf.toString();
	} //}}}

	//{{{ saveRegisters() method
	public static void saveRegisters()
	{
		if(!loaded || !modified)
			return;

		Log.log(Log.MESSAGE,Registers.class,"Saving registers.xml");
		File file1 = new File(MiscUtilities.constructPath(
			jEdit.getSettingsDirectory(), "#registers.xml#save#"));
		File file2 = new File(MiscUtilities.constructPath(
			jEdit.getSettingsDirectory(), "registers.xml"));
		if(file2.exists() && file2.lastModified() != registersModTime)
		{
			Log.log(Log.WARNING,Registers.class,file2 + " changed"
				+ " on disk; will not save registers");
			return;
		}

		jEdit.backupSettingsFile(file2);

		String lineSep = System.getProperty("line.separator");

		BufferedWriter out = null;

		boolean ok = false;

		try
		{
			out = new BufferedWriter(new FileWriter(file1));

			out.write("<?xml version=\"1.0\"?>");
			out.write(lineSep);
			out.write("<!DOCTYPE REGISTERS SYSTEM \"registers.dtd\">");
			out.write(lineSep);
			out.write("<REGISTERS>");
			out.write(lineSep);

			Register[] registers = getRegisters();
			for(int i = 0; i < registers.length; i++)
			{
				Register register = registers[i];
				if(register == null || i == '$' || i == '%')
					continue;

				out.write("<REGISTER NAME=\"");
				if(i == '"')
					out.write("&quot;");
				else
					out.write((char)i);
				out.write("\">");

				out.write(MiscUtilities.charsToEntities(
					register.toString()));

				out.write("</REGISTER>");
				out.write(lineSep);
			}

			out.write("</REGISTERS>");
			out.write(lineSep);

			ok = true;
		}
		catch(Exception e)
		{
			Log.log(Log.ERROR,Registers.class,e);
		}
		finally
		{
			try
			{
				if(out != null)
					out.close();
			}
			catch(IOException e)
			{
			}
		}

		if(ok)
		{
			/* to avoid data loss, only do this if the above
			 * completed successfully */
			file2.delete();
			file1.renameTo(file2);
		}

		registersModTime = file2.lastModified();
		modified = false;
	} //}}}

	//{{{ Private members
	private static Register[] registers;
	private static long registersModTime;
	private static boolean loaded, loading, modified;

	private Registers() {}

	static
	{
		registers = new Register[256];
		registers['$'] = new ClipboardRegister(Toolkit
			.getDefaultToolkit().getSystemClipboard());
	}

	//{{{ loadRegisters() method
	private static void loadRegisters()
	{
		String settingsDirectory = jEdit.getSettingsDirectory();
		if(settingsDirectory == null)
			return;

		File registerFile = new File(MiscUtilities.constructPath(
			jEdit.getSettingsDirectory(),"registers.xml"));
		if(!registerFile.exists())
			return;

		registersModTime = registerFile.lastModified();
		loaded = true;

		Log.log(Log.MESSAGE,jEdit.class,"Loading registers.xml");

		RegistersHandler handler = new RegistersHandler();
		XmlParser parser = new XmlParser();
		parser.setHandler(handler);
		Reader in = null;
		try
		{
			loading = true;
			in = new BufferedReader(new FileReader(registerFile));
			parser.parse(null, null, in);
		}
		catch(XmlException xe)
		{
			int line = xe.getLine();
			String message = xe.getMessage();
			Log.log(Log.ERROR,Registers.class,registerFile + ":"
				+ line + ": " + message);
		}
		catch(FileNotFoundException fnf)
		{
			//Log.log(Log.DEBUG,Registers.class,fnf);
		}
		catch(Exception e)
		{
			Log.log(Log.ERROR,Registers.class,e);
		}
		finally
		{
			loading = false;
			try
			{
				if(in != null)
					in.close();
			}
			catch(IOException io)
			{
				Log.log(Log.ERROR,Registers.class,io);
			}
		}
	} //}}}

	//}}}

	//{{{ Inner classes

	//{{{ Register interface
	/**
	 * A register.
	 */
	public interface Register
	{
		/**
		 * Converts to a string.
		 */
		String toString();

		/**
		 * Sets the register contents.
		 */
		void setValue(String value);
	} //}}}

	//{{{ ClipboardRegister class
	/**
	 * A clipboard register. Register "$" should always be an
	 * instance of this.
	 */
	public static class ClipboardRegister implements Register
	{
		Clipboard clipboard;

		public ClipboardRegister(Clipboard clipboard)
		{
			this.clipboard = clipboard;
		}

		/**
		 * Sets the clipboard contents.
		 */
		public void setValue(String value)
		{
			StringSelection selection = new StringSelection(value);
			clipboard.setContents(selection,null);
		}

		/**
		 * Returns the clipboard contents.
		 */
		public String toString()
		{
			try
			{
				String selection = (String)(clipboard
					.getContents(this).getTransferData(
					DataFlavor.stringFlavor));

				boolean trailingEOL = (selection.endsWith("\n")
					|| selection.endsWith(System.getProperty(
					"line.separator")));

				// Some Java versions return the clipboard
				// contents using the native line separator,
				// so have to convert it here
				BufferedReader in = new BufferedReader(
					new StringReader(selection));
				StringBuffer buf = new StringBuffer();
				String line;
				while((line = in.readLine()) != null)
				{
					// broken Eclipse workaround!
					// 24 Febuary 2004
					if(line.endsWith("\0"))
					{
						line = line.substring(0,
							line.length() - 1);
					}
					buf.append(line);
					buf.append('\n');
				}
				// remove trailing \n
				if(!trailingEOL && buf.length() != 0)
					buf.setLength(buf.length() - 1);
				return buf.toString();
			}
			catch(Exception e)
			{
				Log.log(Log.NOTICE,this,e);
				return null;
			}
		}
	} //}}}

	//{{{ StringRegister class
	/**
	 * Register that stores a string.
	 */
	public static class StringRegister implements Register
	{
		private String value;

		/**
		 * Creates a new string register.
		 * @param value The contents
		 */
		public StringRegister(String value)
		{
			this.value = value;
		}

		/**
		 * Sets the register contents.
		 */
		public void setValue(String value)
		{
			this.value = value;
		}

		/**
		 * Converts to a string.
		 */
		public String toString()
		{
			return value;
		}

		/**
		 * Called when this register is no longer available. This
		 * implementation does nothing.
		 */
		public void dispose() {}
	} //}}}

	//{{{ RegistersHandler class
	static class RegistersHandler extends HandlerBase
	{
		//{{{ resolveEntity() method
		public Object resolveEntity(String publicId, String systemId)
		{
			if("registers.dtd".equals(systemId))
			{
				// this will result in a slight speed up, since we
				// don't need to read the DTD anyway, as AElfred is
				// non-validating
				return new StringReader("<!-- -->");

				/* try
				{
					return new BufferedReader(new InputStreamReader(
						getClass().getResourceAsStream("registers.dtd")));
				}
				catch(Exception e)
				{
					Log.log(Log.ERROR,this,"Error while opening"
						+ " recent.dtd:");
					Log.log(Log.ERROR,this,e);
				} */
			}

			return null;
		} //}}}

		//{{{ attribute() method
		public void attribute(String aname, String value, boolean isSpecified)
		{
			if(aname.equals("NAME"))
				registerName = value;
		} //}}}

		//{{{ doctypeDecl() method
		public void doctypeDecl(String name, String publicId,
			String systemId) throws Exception
		{
			if("REGISTERS".equals(name))
				return;

			Log.log(Log.ERROR,this,"registers.xml: DOCTYPE must be REGISTERS");
		} //}}}

		//{{{ endElement() method
		public void endElement(String name)
		{
			if(name.equals("REGISTER"))
			{
				if(registerName == null || registerName.length() != 1)
					Log.log(Log.ERROR,this,"Malformed NAME: " + registerName);
				else
					setRegister(registerName.charAt(0),charData);
			}
		} //}}}

		//{{{ charData() method
		public void charData(char[] ch, int start, int length)
		{
			charData = new String(ch,start,length);
		} //}}}

		//{{{ Private members
		private String registerName;
		private String charData;
		//}}}
	} //}}}

	//}}}
}