XLObject 2.0.2a

XLObject is a clone of basic services offered by the Qt object model, redesigned around modern features of the C++ language. Signals and slots are used for communication between objects. There are instances when we want some objects to know the changes of a particular object without having to write code for each interested object.
This design is common in GUI programming, where another widget needs to be notified implicitly of the change of one widget. Since the widget needs to be usable everywhere, the design should be as generic as possible. The event-generating widget should not need to know how or which widgets are informed of the event.
In older C-based toolkits, this functionality is achieved by using "callbacks" - registering pointers to functions to a processing function. The problem with callbacks is that they are not type safe, prone to crashes, and are strongly tied to the processing function.
Signal and Slots is an implementation of the Observer design pattern made popular by the Qt toolkit. It provides a much safer alternative to callbacks in addition to being built on the principles of object-oriented programming. Qt implemented this feature by dynamically adding extra information to classes during compile time with the help of an external meta object compiler.
XL Signal and Slots achieves the same functionality without the meta compiler by taking advantage of C++ templates. This direct approach is very fast compared to Qts string-based approach with the added benefit of:
Allowing all member functions to be treated as slots.
No longer needing specification of non-standard macros during class definitions.
At the same time, the library tries to follow the design of Qt as closely as possible where it:
Automatically severs the connection if either receiver or sender is destroyed so your program does not crash during the process of emitting a signal.
Lets receiver objects know which sender Object emitted the signal
Lets the compiler catch type mismatches.
Allows a slot to have a shorter signature than the signal without having to rebind types.
Optionally allows objects to be organized as object trees and achieving a concept that is more or less similar to garbage-collection.
The library aims to achieve the core signal and slots functionality very well and at the same time be as less complicated as possible. In around a thousand lines of code, the library is capable of being embedded into the application in a very tiny amount of space.
Enhancements:
- This release fixes a severe memory leak in the thread class.
- The documentation was improved in some of the utility classes.
- Options are provided to specify an optional address in server sockets.
- Some additional fixes were made in the core socket classes.