1. Usage When sub-system very complex and has many subsystems it make sense to unify access to it by providing single interface called facade. Facade isolate subsystems from direct calls and such way reducing dependency between modules and improve re-usability . 2. UML class diagram 3. Pros It helps to use subsystem as only single […]
1. Usage you need to use many objects lets put 1000-100000. They are similar and related. For example icons of folders and files in Windows. To allow them share similar properties from one side but be ready to be customized we can use Flyweight pattern. Inner proprieties shared by all objects of group called Intrinsic […]
10 things you need to overcome to be successful. Procrastination – Just remind yourself the more fear you feel about a specific task, the more certain you can be that task is important to you and your growth. Limiting beliefs of others – That’s too hard, that won’t work… Remember, if everyone listened to the […]
1. Usage Composite is composing tree like structures as single object(container), and let clients to go through such composed objects and regular objects uniformly. Qt Library has implicit support of Composite pattern due to ability to SetParent of QObject. 2. UML class diagram (source: http://www.cs.unc.edu/~stotts/GOF/hires/pat4cfso.htm) Typical Composite Object structure: 3. Pros It makes it easy […]
1. Usage Kind of “2D Abstraction” (or by Rumbaugh “nested generalizations”) both on Interface(Window in example below) and on Implementation(WindowImp). So both Abstraction and Implementation should be extensible by sub-classing.Another name for this pattern is Handle-Body.This Pattern often used in Window Libraries e.g. AWT. Qt library uses this pattern for switching Style at run-time. Reasons […]