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L03C: Assignment - Implementing the Displayable Interface

JAVA Coding Question. This Is The L03C"Implementing The Displayable Interface",

Assignment Objectives

1. Practice on implementing a MVC project
2. Implement interfaces

Deliverables

A zipped Java project according to the How to submit Labs and Assignments.

O.O. Requirements (these items will be part of your grade)

1. One class, one file. Don't create multiple classes in the same .java file
2. Don't use static variables and methods
3. Encapsulation: make sure you protect your class variables and provide access to them through get and set methods
4. all the classes are required to have a constructor that receivesallthe attributes as parameters and update the attributes accordingly
5. Follow Horstmann's Java Language Coding Guidelines
6. Organized in packages (MVC - Model - View Controller)

Contents

Implement a Displayable interface. This new interface will help the graphics implementation in the next assignment.

FootballPlayerData

FootballPlayerData will now implement a second interface, called Displayable.

The NetBeans Project

This new assignment brings in a new interface, Displayable.

You should keep building from your previous TableMember/TableData Netbeans project.

• • App.java
• Controller
  • Controller.java
• Model
  • Displayable.java
  • FootballPlayer.java
  • FootballPlayerData.java
  • Height.java
  • Model.java
  • Person.java
  • TableData.java
  • TableMember.java
• View
  • View.java

Below is therequiredinitial code inappand inController.

public class app

{

public static void main(String[] args)

{

View view = new View();

Model model = new Model();

Controller controller = new Controller(view, model);

}

}

The code for Controller.java

Download Controller.java

public class Controller

{

Model model;

View view;

public Controller(View v, Model m)

{

model = m;

view = v;

//============================================================================

String sfltd, slltd, slbd, slth;

//display using the default values created by Model, and FootballPlayerData

//These values should be set in the Constructor of FootballPlayerData

//15 lines being displayed with the first line being 0

sfltd = " " + this.model.getFpData().getFirstLineToDisplay();

slltd = " " + this.model.getFpData().getLastLineToDisplay();

this.model.getFpData().setLinesBeingDisplayed(10);

this.model.getFpData().setFirstLineToDisplay(100);

sfltd = " " + this.model.getFpData().getFirstLineToDisplay();

slltd = " " + this.model.getFpData().getLastLineToDisplay();

slbd = " " + this.model.getFpData().getLinesBeingDisplayed();

slth = " " + this.model.getFpData().getLineToHighlight();

slbd = " " + this.model.getFpData().getLinesBeingDisplayed();

slth = " " + this.model.getFpData().getLineToHighlight();

this.view.basicDisplay("First Line = " + sfltd + ", Last Line = " + slltd + ", Lines Being Displayed = " + slbd + ", Line to Highlight=" + slth);

//============================================================================

//Sets news values and displays them

this.model.getFpData().setLinesBeingDisplayed(10);

this.model.getFpData().setFirstLineToDisplay(100);

sfltd = " " + this.model.getFpData().getFirstLineToDisplay();

slltd = " " + this.model.getFpData().getLastLineToDisplay();

slbd = " " + this.model.getFpData().getLinesBeingDisplayed();

slth = " " + this.model.getFpData().getLineToHighlight();

this.view.basicDisplay("First Line = " + sfltd + ", Last Line = " + slltd + ", Lines Being Displayed = " + slbd + ", Line to Highlight=" + slth);

sfltd = " " + this.model.getFpData().getFirstLineToDisplay();

slltd = " " + this.model.getFpData().getLastLineToDisplay();

slbd = " " + this.model.getFpData().getLinesBeingDisplayed();

slth = " " + this.model.getFpData().getLineToHighlight();

this.view.basicDisplay("First Line = " + sfltd + ", Last Line = " + slltd + ", Lines Being Displayed = " + slbd + ", Line to Highlight=" + slth);

//============================================================================

//Sets news values and displays them

this.model.getFpData().setLinesBeingDisplayed(20);

this.model.getFpData().setFirstLineToDisplay(10);

sfltd = " " + this.model.getFpData().getFirstLineToDisplay();

slltd = " " + this.model.getFpData().getLastLineToDisplay();

slbd = " " + this.model.getFpData().getLinesBeingDisplayed();

slth = " " + this.model.getFpData().getLineToHighlight();

this.view.basicDisplay("First Line = " + sfltd + ", Last Line = " + slltd + ", Lines Being Displayed = " + slbd + ", Line to Highlight=" + slth);

//============================================================================

//Sets news values and displays them

this.model.getFpData().setLinesBeingDisplayed(15);

this.model.getFpData().setFirstLineToDisplay(-5);

sfltd = " " + this.model.getFpData().getFirstLineToDisplay();

slltd = " " + this.model.getFpData().getLastLineToDisplay();

slbd = " " + this.model.getFpData().getLinesBeingDisplayed();

slth = " " + this.model.getFpData().getLineToHighlight();

sfltd = " " + this.model.getFpData().getFirstLineToDisplay();

slltd = " " + this.model.getFpData().getLastLineToDisplay();

slbd = " " + this.model.getFpData().getLinesBeingDisplayed();

slth = " " + this.model.getFpData().getLineToHighlight();

this.view.basicDisplay("First Line = " + sfltd + ", Last Line = " + slltd + ", Lines Being Displayed = " + slbd + ", Line to Highlight=" + slth);

//============================================================================

//Sets news values and displays them

this.model.getFpData().setLinesBeingDisplayed(12);

this.model.getFpData().setFirstLineToDisplay(300);

sfltd = " " + this.model.getFpData().getFirstLineToDisplay();

slltd = " " + this.model.getFpData().getLastLineToDisplay();

slbd = " " + this.model.getFpData().getLinesBeingDisplayed();

slth = " " + this.model.getFpData().getLineToHighlight();

this.view.basicDisplay("First Line = " + sfltd + ", Last Line = " + slltd + ", Lines Being Displayed = " + slbd + ", Line to Highlight=" + slth);

}

}

The code above will test you implementation of the interfaceDisplayable.

If your implementation is correct it will generate the display below:

First Line = 0, Last Line = 14, Lines Being Displayed = 15, Line to Highlight= 0

First Line = 100, Last Line = 109, Lines Being Displayed = 10, Line to Highlight= 0

First Line = 10, Last Line = 29, Lines Being Displayed = 20, Line to Highlight= 0

First Line = 0, Last Line = 14, Lines Being Displayed = 15, Line to Highlight= 0

First Line = 112, Last Line = 123, Lines Being Displayed = 12, Line to Highlight= 0

Functionality

There is a new interface in this project, Displayable

• Displayable.java

package Model;

public interface Displayable

{

public int getFirstLineToDisplay();

public int getLineToHighlight();

public int getLastLineToDisplay();

public int getLinesBeingDisplayed();

public void setFirstLineToDisplay(int firstLine);

public void setLineToHighlight(int highlightedLine);

public void setLastLineToDisplay(int lastLine);

public void setLinesBeingDisplayed(int numberOfLines);

}

• Displayable.java (make sure you read the FAQ below for more details)
  • public int getFirstLineToDisplay();
  • public void setFirstLineToDisplay(int firstLine);
    • these first two methods are about anintattribute that will hold the number of the first line to be displayed. The number represents the index of an element in the array of the class that implements the TableData interface.
  • public int getLineToHighlight();
  • public void setLineToHighlight(int highlightedLine);
    • the two methods above are about anintattribute that will hold the number of the line on the screen that should be highlighted. It will be used only in a later assignment but it is part of the interface and needs to be implemented even if it is not fully functional yet.
  • public int getLastLineToDisplay();
  • public void setLastLineToDisplay(int lastLine);
    • these two methods are about anintattribute that will hold the number of the last line to be displayed. The number represents the index of an element in the array of the class that implements the TableData interface.
  • public int getLinesBeingDisplayed();
  • public void setLinesBeingDisplayed(int numberOfLines);
    • these two methods are about anintattribute that will hold the number of the lines that will appear on the screen at one time. It will be most likely 20 but it should a variable. The application should work with any number of lines. So if this number is set to 10 or 15, this is the number of lines that should appear on the screen.

FAQ - Frequently Asked Questions

What are the initial (default) values for the 4 new variables?

firstLineToDisplay

• for testing purposes, it should be set to 0. This is the firs record in the ArrayList to be displayed on the first line on the screen. But any reasonable value is fine. We have 124 records in the ArrayList, so in principle any number from 0 to 123 would work, although last line impose some limits.

lastLineToDisplay

• Last line is dependent on the values of first line and lines being displayed.

linesBeingDisplayed

• This is the number of lines on the screen. It should be15.

lineToHighlight

• it will not be used in this assignment and can be set to 0.

What happens when invalid values (too small-negative or too large-outside the table size) are set to firstLineToDisplay?

firstLineToDisplay

• when setFirstLineToDisplay receives a negative number
  • firstLine needs to be set to 0
  • lastLine needs to be recalculated based on "0" and on the number of lines being displayedlinesBeingDisplayed
• when setFirstLineToDisplay receives a number that is larger that the table size (the players ArrayList size) - linesBeingDisplayed
  • firstLine needs to be set to a number that leaves room to fit linesBeing displayed
  • lastLine needs to be recalculated based on firstLine and on the number of lines being displayedlinesBeingDisplayed

1. Practice on implementing a MVC project
2. Implement interfaces

Deliverables

A zipped Java project according to theHow to submit Labs and Assignments.

O.O. Requirements (these items will be part of your grade)

1. One class, one file. Don't create multiple classes in the same .java file
2. Don't use static variables and methods
3. Encapsulation:make sure you protect your class variables and provide access to them through get and set methods
4. all the classes are required to have a constructor that receivesallthe attributes as parameters and update the attributes accordingly
5. FollowHorstmann's Java Language Coding Guidelines
6. Organized in packages (MVC - Model - View Controller)

Contents

Implement a Displayable interface. This new interface will help the graphics implementation in the next assignment.

FootballPlayerData

FootballPlayerData will now implement a second interface, called Displayable.

The NetBeans Project

This new assignment brings in a new interface, Displayable.

You should keep building from your previous TableMember/TableData Netbeans project.

App.java Controller Controller.java Model Displayable.java FootballPlayer.java FootballPlayerData.java Height.java Model.java Person.java TableData.java TableMember.java View View.java

Below is therequiredinitial code inappand inController.

public class app { public static void main(String[] args) { View view = new View(); Model model = new Model(); Controller controller = new Controller(view, model); } }The code forController.java public class Controller { Model model; View view; public Controller(View v, Model m) { model = m; view = v; //============================================================================ String sfltd, slltd, slbd, slth; //display using the default values created by Model, and FootballPlayerData //These values should be set in the Constructor of FootballPlayerData //15 lines being displayed with the first line being 0 sfltd = " " + this.model.getFpData().getFirstLineToDisplay(); slltd = " " + this.model.getFpData().getLastLineToDisplay(); slbd = " " + this.model.getFpData().getLinesBeingDisplayed(); slth = " " + this.model.getFpData().getLineToHighlight(); this.view.basicDisplay("First Line = " + sfltd + ", Last Line = " + slltd + ", Lines Being Displayed = " + slbd + ", Line to Highlight=" + slth); //============================================================================ //Sets news values and displays them this.model.getFpData().setLinesBeingDisplayed(10); this.model.getFpData().setFirstLineToDisplay(100); sfltd = " " + this.model.getFpData().getFirstLineToDisplay(); slltd = " " + this.model.getFpData().getLastLineToDisplay(); slbd = " " + this.model.getFpData().getLinesBeingDisplayed(); slth = " " + this.model.getFpData().getLineToHighlight(); this.view.basicDisplay("First Line = " + sfltd + ", Last Line = " + slltd + ", Lines Being Displayed = " + slbd + ", Line to Highlight=" + slth); //============================================================================ //Sets news values and displays them this.model.getFpData().setLinesBeingDisplayed(20); this.model.getFpData().setFirstLineToDisplay(10); sfltd = " " + this.model.getFpData().getFirstLineToDisplay(); slltd = " " + this.model.getFpData().getLastLineToDisplay(); slbd = " " + this.model.getFpData().getLinesBeingDisplayed(); slth = " " + this.model.getFpData().getLineToHighlight(); this.view.basicDisplay("First Line = " + sfltd + ", Last Line = " + slltd + ", Lines Being Displayed = " + slbd + ", Line to Highlight=" + slth); //============================================================================ //Sets news values and displays them this.model.getFpData().setLinesBeingDisplayed(15); this.model.getFpData().setFirstLineToDisplay(-5); sfltd = " " + this.model.getFpData().getFirstLineToDisplay(); slltd = " " + this.model.getFpData().getLastLineToDisplay(); slbd = " " + this.model.getFpData().getLinesBeingDisplayed(); slth = " " + this.model.getFpData().getLineToHighlight(); this.view.basicDisplay("First Line = " + sfltd + ", Last Line = " + slltd + ", Lines Being Displayed = " + slbd + ", Line to Highlight=" + slth); //============================================================================ //Sets news values and displays them this.model.getFpData().setLinesBeingDisplayed(12); this.model.getFpData().setFirstLineToDisplay(300); sfltd = " " + this.model.getFpData().getFirstLineToDisplay(); slltd = " " + this.model.getFpData().getLastLineToDisplay(); slbd = " " + this.model.getFpData().getLinesBeingDisplayed(); slth = " " + this.model.getFpData().getLineToHighlight(); this.view.basicDisplay("First Line = " + sfltd + ", Last Line = " + slltd + ", Lines Being Displayed = " + slbd + ", Line to Highlight=" + slth); } }

example output

The code above will test you implementation of the interfaceDisplayable.

If your implementation is correct it will generate the display below:

First Line = 0, Last Line = 14, Lines Being Displayed = 15, Line to Highlight= 0 First Line = 100, Last Line = 109, Lines Being Displayed = 10, Line to Highlight= 0 First Line = 10, Last Line = 29, Lines Being Displayed = 20, Line to Highlight= 0 First Line = 0, Last Line = 14, Lines Being Displayed = 15, Line to Highlight= 0 First Line = 112, Last Line = 123, Lines Being Displayed = 12, Line to Highlight= 0Functionality

There is a new interface in this project, Displayable

• Displayable.javaDownload Displayable.java

package Model; public interface Displayable { public int getFirstLineToDisplay(); public int getLineToHighlight(); public int getLastLineToDisplay(); public int getLinesBeingDisplayed(); public void setFirstLineToDisplay(int firstLine); public void setLineToHighlight(int highlightedLine); public void setLastLineToDisplay(int lastLine); public void setLinesBeingDisplayed(int numberOfLines); }

• Displayable.java (make sure you read the FAQ below for more details)
  • public int getFirstLineToDisplay();
  • public void setFirstLineToDisplay(int firstLine);
    • these first two methods are about anintattribute that will hold the number of the first line to be displayed. The number represents the index of an element in the array of the class that implements the TableData interface.
  • public int getLineToHighlight();
  • public void setLineToHighlight(int highlightedLine);
    • the two methods above are about anintattribute that will hold the number of the line on the screen that should be highlighted. It will be used only in a later assignment but it is part of the interface and needs to be implemented even if it is not fully functional yet.
  • public int getLastLineToDisplay();
  • public void setLastLineToDisplay(int lastLine);
    • these two methods are about anintattribute that will hold the number of the last line to be displayed. The number represents the index of an element in the array of the class that implements the TableData interface.
  • public int getLinesBeingDisplayed();
  • public void setLinesBeingDisplayed(int numberOfLines);
    • these two methods are about anintattribute that will hold the number of the lines that will appear on the screen at one time. It will be most likely 20 but it should a variable. The application should work with any number of lines. So if this number is set to 10 or 15, this is the number of lines that should appear on the screen.

FAQ - Frequently Asked Questions

What are the initial (default) values for the 4 new variables?

firstLineToDisplay

• • for testing purposes, it should be set to 0. This is the firs record in the ArrayList to be displayed on the first line on the screen. But any reasonable value is fine. We have 124 records in the ArrayList, so in principle any number from 0 to 123 would work, although last line impose some limits.

lastLineToDisplay

• • Last line is dependent on the values of first line and lines being displayed.

linesBeingDisplayed

• • This is the number of lines on the screen. It should be15.

lineToHighlight

• • it will not be used in this assignment and can be set to 0.

What happens when invalid values (too small-negative or too large-outside the table size) are set to firstLineToDisplay?

firstLineToDisplay

• • when setFirstLineToDisplay receives a negative number
    • firstLine needs to be set to 0
    • lastLine needs to be recalculated based on "0" and on the number of lines being displayedlinesBeingDisplayed
• • when setFirstLineToDisplay receives a number that is larger that the table size (the players ArrayList size) - linesBeingDisplayed
    • firstLine needs to be set to a number that leaves room to fit linesBeing displayed
    • lastLine needs to be recalculated based on firstLine and on the number of lines being displayedlinesBeingDisplayed