lexi_0_2_alpha文本编辑器java源码

The Lexi Project Manifesto -------------------------- The goal of the Lexi project is to develop an Open Source word processing suite written entirely in Java. Why Should We Do This? ---------------------- There is no shortage of word processing software available to end users. In addition to the ubiquitous Microsoft Office applications, there are numerous proprietary and open source word processing applications. Open source offerings include the OpenOffice / StarOffice suites, as well as the KOffice and Gnome Office suites that are included in KDE and Gnome desktop environments respectively. But what is missing is a word processing suite that is capable of running in a Pure Java environment. Why Is Pure Java Important? --------------------------- Pure Java is important for many reasons, but the following reasons stand out. The first reason is that an application written in Pure Java is (in theory) portable to a wide range of hardware / operating system platforms. An application written in C or C++ is typically limitted to a relatively small range of platforms. For example, Microsoft Word is restricted to (mostly) Microsoft's operating systems, KOffice and Gnome Office applications are restricted to Linux environments, and so on. OpenOffice is available on a wider range of platforms, but only because the developers have invested a lot of effort in platform independence. By contrast, a pure Java application should run on any Java platform that supports the appropriate version of the J2SE, J2EE or J2ME class libraries (or equivalent open source class libraries). If we ignore the problem of incomplete or buggy libraries, an application should be portable across a wide range of platforms, with little effort on the part of the application developer. A second reason that Pure Java is important is that the Java platform has distinct advantages in terms of system security. Since the Java virtual machine is (in theory) type safe, an application written in Pure Java cannot be the cause of a memory corruption. (If such problems exist, they will be due to bugs in the JVM, JIT compiler, core native libraries or similar.) This means that we don't have to worry about sloppy application code with buffer overrun bugs. In addition, Java's built-in security framework allows a large Java application (or Java Operating System if you like) to implement fine-grained access control and sandboxing of untrusted code. This allows sensitive objects to be shared with code that is not entirely trusted. By contrast, in a classical multi-user operating system you have to rely on a trusted kernel and hardware supported memory access control. (Admittedly, Java Security is not generally well understood, and it is not clear that we have the tools to manage and use it.) The Prospect of a Java Operating System --------------------------------------- Many things follow from the advantages of Pure Java. One of them is the prospect of a safe operating system; i.e. an operating system which is resistant to security problems that plague current systems and applications. JVM safety and the Java Security framework means (in theory) that we can safely put all of a user's applications into one JVM. This makes it easier to build system components and applications that are richer and better integrated. For example, the windowing subsystem could be integrated with user preferences and layout scripting so that look-and-feel tailoring can be done uniformly across all GUI-based applications. In there are a number of issues that would need to be addressed. For example: 1) We need a high quality JVM that incorporates the nececessary OS kernel infrastructure (e.g. processor & memory management, device drivers, network drivers, etc) to boot and run on a bare PC. Support for isolates or something similar is essential. [The JNode project is making good progress on this.] 2) We need to see if the current Java Security framework is suitable for securing a multi-user operating system. 3) We need an ecosystem of Java applications to run on the Java operating system. And Hence ... ------------- There are a lot of useful (often open-sourced) Java applications. There are text editors, project management and software development tools, databases, email tools, web browsers and many more. (The JDesktop effort has pulled together >100 "desktop" applications.) But one important thing that seems to be missing is an "office suite" implemented in Java. In my searches, I have not come across anything that even remotely approaches the functionality of Open Office or Microsoft Office that is implemented in Java. And thats what we are trying to do here.