Hints for COMP104 Lab 11

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Hints for COMP104 Lab 11
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What Should You Submit?

• 3 files to submit
• lab11.h
• Definition of struct Node
• Definition of class player
• lab11.cpp
• implementation of member functions in class
  player
• main.cpp
• main() function
• Given on the lab page. No modification is allowed!

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Requirements

• Implementation of movie player using class
• User-defined constructor
• Frames in doubly linked list
• Private data members (e.g. Head, cur)
• NO pointers as parameters for member functions
• NO global variables except constants
• NO memory leakage

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What should you do?

• The program will have the same functionalities as
  the one in Lab 10
• You dont have to write all the codes yourself
• Modify the version from Lab 10
• But you have to understand the similarities and
  differences between Labs 10 and 11
• Which portions are you going to modify?

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What should you do?

• Similarities in Labs 10 and 11
• Functions to perform each sub-task
• States/components of player (e.g. List of frames)
  have to be kept
• Differences between Labs 10 and 11
• Functions in Lab 10 are defined globally
• Everyone could use the functions anywhere for any
  number of times
• Functions in Lab 11 are defined in class player
• Only a subset of functions are visible globally
  (i.e. public functions)
• Remaining functions are private
• States of player in Lab 10 is kept by function
  main() and start_104player()
• States of player in Lab 11 is kept by the class
  player

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What should you do?

• Understand the program structure of Lab 10
• Whats the logic flow of main()?
• Whats the purpose of each function?
• How are they related?

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Modifications from Lab 10

• Functions are defined in class player
• Most of them are found in lab 10
• Which of them should be public?
• Which of them should be private?
• Need some changes as NO pointer parameters could
  be used
• Need some new ones
• Constructor (more explanation in later slides)
• Any more?
• Put the implementations in lab11.cpp
• Put the prototypes (inside the class) in lab11.h

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Modifications from Lab 10

• State/components of player are kept by the class
  player
• Most of them are found in main() and
  start_104player() of Lab 10
• E.g. Head pointer to the doubly linked list
• Any more?
• Remember You cant use pointers as function
  parameters in Lab 11
• How to access those parameters?
• They have to be kept by the class player (as data
  members)
• Put the declarations (inside the class) in lab11.h

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Modifications from Lab 10

• Constructor of class player
• Initialize data members in class player
• Parameters are required
• Try to examine main.cpp to guess what it is

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Final Notes

• Normal functions and classs member functions are
  different
• How to separate them in the code?
• will always before the names of
  member functions
• E.g. void playerstart()
• Constructors have NO return types (not even void)!