 
 subsection3_4_1.html  TixUser.html  subsection3_3_2.html  tableofcontents3_1.html   Next: subsection3_4_1.html Widget Classes and Up: TixUser.htmlPython Tix User Guide  Previous: subsection3_3_2.html Tix Commands    Tix Object Oriented Programming 
Tix comes with a simple object oriented programming (OOP) framework,
the Tix Intrinsics, for writing mega-widgets. The Tix Intrinsics is
not a general purpose OOP system and it does not support some features
found in general purpose OOP systems such as [incr Tcl] or Python. However, 
provides a simple and efficient interface for creating mega-widgets so
that you can avoid the complexity and overheads of the general purpose
OOP extensions.
The hard thing about programming with mega-widgets is to make sure
that each instance you create can handle its own activities. Events
must be directed to the right widget, procedures must act on data that
is internal to that widget, and users should be able to change the
options associated with the widget. For instance, we'll show an arrow
widget that needs to know what direction it's pointing; this requires
each instance of the widget to have its own variable. Furthermore, each
widget must respond properly to changes requested by the application
programmer during the program's run.
 
 subsection3_4_1.html#SECTION00041000000000000000 Widget Classes and Widget Instances  
 subsubsection3_4_1_1.html#SECTION00041100000000000000 Widget Instances  
 subsection3_4_2.html#SECTION00042000000000000000 Widget Class Declaration  
 subsubsection3_4_2_1.html#SECTION00042100000000000000 Using the tixWidgetClass Command  
 subsection3_4_3.html#SECTION00043000000000000000 Writing Methods  
 subsubsection3_4_3_1.html#SECTION00043100000000000000 Declaring Public Methods  
 subsection3_4_4.html#SECTION00044000000000000000 Standard Initialization Methods  
 subsubsection3_4_4_1.html#SECTION00044100000000000000 The InitWidgetRec Method  
 subsectionstar3_4_5.html#SECTION00045000000000000000 Chaining Methods  
 subsubsection3_4_5_1.html#SECTION00045100000000000000 The ConstructWidget Method  subsubsection3_4_5_2.html#SECTION00045200000000000000 The SetBindings Method  
 subsection3_4_6.html#SECTION00046000000000000000 Declaring and Using Variables  
 subsubsection3_4_6_1.html#SECTION00046100000000000000 Initialization of Public Variables  subsubsection3_4_6_2.html#SECTION00046200000000000000 Public Variable Configuration Methods http://tix.sourceforge.nethttp://tix.sourceforge.net 