Sorting Arrays with CompareTo
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Programming Questions
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1 year ago
This is a test program for sorting an Array of Objects, based on 1 of the objects fields. I was able to overload Java's CompareTo method and call Arrays.sort(Object) -- This works well if the sort field is fixed. But I want an example where I can press "r", "g" or "a" on the keyboard and it will sort dynamically based on correct field (response, gender, age).
It is compiling and running, but I'm getting a strange bug where the first one or two Key Pressed work okay, then I have to hit the key TWICE for it to sort. And there a bug where hitting, say, 'r' and 'g' intermittently causes problems... I am stumped. Any ideas?
- PFont font;
- Person[] people;
- Person[] tmp;
- char sortVal;
- void setup()
- {
- size(800, 400);
- font = loadFont("HelveticaNeue-Light-18.vlw");
- textFont(font);
- textAlign(CENTER, CENTER);
- noStroke();
- smooth();
- //import the XML data
- XMLElement xml = new XMLElement(this, "people.xml");
- //split all the people up into an array of XMLElements
- XMLElement[] kids = xml.getChildren("row");
- //Make a new, blank array that will hold 10 People
- people = new Person[10];
- //Go through the array of people, fill that index with a new Person, based on the
- //information in this index of the XMLElement array.
- for (int i=0; i<people.length; i++)
- {
- //create temp vars to store the answer, gender, age data and
- //pass them into the Constructor for this Person.
- int res = int(kids[i].getChild("answer").getContent());
- int gend = int(kids[i].getChild("gender").getContent());
- int age = int(kids[i].getChild("age").getContent());
- people[i] = new Person(age, res, gend);
- println(people[i].sorter);
- }
- tmp = people;
- }
- void draw()
- {
- background(255, 250, 240);
- for (int i=0; i<people.length; i++)
- {
- tmp[i].update();
- tmp[i].display(50+(i*70), height/2);
- }
- }
- void keyPressed()
- {
- if (key=='r')
- {
- sortVal='r'; //reminder: sortVal is global -- not part of the Person class...
- }
- else if (key=='a')
- {
- sortVal='a';
- }
- else if (key=='g')
- {
- sortVal='g';
- }
- else
- {
- println("Not a valid sort option");
- }
- println(sortVal);
- tmp = people; //replace the reference to the original People array
- Arrays.sort(tmp); //sort the reference
- // the idea here was to always sort from the original ordering...
- }
- //The Person Class
- class Person implements Comparable<Person>
- {
- int age;
- int response;
- int gender;
- int sorter;
- int original;
- Person(int _age, int _response, int _gender)
- {
- age = _age;
- response = _response;
- gender = _gender;
- original = 0;
- }
- void display(float x, float y)
- {
- if (gender==0)
- fill(80, 100, 230);
- else
- fill(230, 80, 170);
- ellipse(x, y, age, age);
- char temp;
- if (response==0) temp='N';
- else temp='Y';
- fill(255);
- text(temp, x, y);
- fill(100);
- text(age, x, height/2-50);
- }
- void update()
- {
- if (sortVal=='a') sorter=age;
- else if (sortVal=='g') sorter=gender;
- else if (sortVal=='r') sorter=response;
- else sorter=original;
- }
- /* Overload compareTo method */
- public int compareTo(Person tmp)
- {
- if (this.sorter < tmp.sorter)
- {
- /* instance lt received */
- return -1;
- }
- else if (this.sorter > tmp.sorter)
- {
- /* instance gt received */
- return 1;
- }
- /* instance == received */
- return 0;
- }
- }
The data is being read from this XML file:
<rows>
<row>
<age>23</age>
<answer>1</answer>
<gender>1</gender>
</row>
<row>
<age>24</age>
<answer>1</answer>
<gender>0</gender>
</row>
<row>
<age>15</age>
<answer>0</answer>
<gender>1</gender>
</row>
<row>
<age>32</age>
<answer>1</answer>
<gender>1</gender>
</row>
<row>
<age>30</age>
<answer>1</answer>
<gender>0</gender>
</row>
<row>
<age>29</age>
<answer>0</answer>
<gender>0</gender>
</row>
<row>
<age>29</age>
<answer>0</answer>
<gender>0</gender>
</row>
<row>
<age>28</age>
<answer>0</answer>
<gender>1</gender>
</row>
<row>
<age>45</age>
<answer>0</answer>
<gender>1</gender>
</row>
<row>
<age>62</age>
<answer>1</answer>
<gender>1</gender>
</row>
</rows>
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