Sort an ArrayList of Points in page line order

Question

I need to order an ArrayList of Points in the page line order. Assume these points as minX and minY of Rectangle of text.

Say like I have points like below

Point(100,10), Point(110, 20), Point(125, 5), Point(130, 10)

The Sorted order should be aligned as page line items

i.e Point(125, 5), Point(100,10), Point(130, 10), Point(110, 20)

I was trying to sort the Points by Y coordinate first and then by X coordinate

public int compare(final Point a, final Point b) {
    if (a.y() < b.y()) {
        return -1;
    }else if (a.y() > b.y()) {
        return 1;
    }else {
        return 0;
    }
}

public int compare(final Point a, final Point b) {
    if (a.x() < b.x()) {
        return -1;
    }else if (a.x() > b.x()) {
        return 1;
    }else {
        return 0;
    }
}

Below is the order I am getting now

Line = 0.00 2450 00 SewiceTax @14 on are, Sub Total Two Thousand Four Hundred Fifty Only INR

Line = Swachh Bharat Cass @ O 50 42':

Line = Knshu Kaiyan Cass @ 0‘50 “5

Line = Less Advance Paid

Line = 2450 GD Balance Payable

Expected was

Line = Sub Total Two Thousand Four Hundred Fifty Only 0.00 2450 00INR SewiceTax @14 on are,

Have you tried something yet? I'm sure there is a SO question which already covers how to create a customer comparator for a point class, to be used when sorting a list of points. — Tim Biegeleisen, Aug 23 '17 at 06:32
Would be nice to see what you already tried, we are not here to programm you an algorithm^^ — Alexander Heim, Aug 23 '17 at 06:33
Possible duplicate of [Sort by multiple columns, Java 8](https://stackoverflow.com/questions/32204594/sort-by-multiple-columns-java-8) — Raniz, Aug 23 '17 at 06:42
Have updated the question with the code and the actual and expected result. — Ranju, Aug 23 '17 at 06:48

score 0 · Answer 1 · answered Aug 23 '17 at 06:45

0

Use Comparator, and override compare() according to your usecase. These links will help you

How to sort ArrayList using Comparator?

How to use Comparator in Java to sort

answered Aug 23 '17 at 06:45

bibbsey

969
2
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14

score 0 · Accepted Answer · edited Feb 15 '21 at 14:57

0

This should work for you. Sort the Points by Y coordinate first and then by X coordinate.

Point p1 = new Point(12,  15);
Point p2 = new Point(13,  12);
Point p3 = new Point(14,  15);

List<Point> list = new ArrayList<>();
list.add(p1);
list.add(p2);
list.add(p3);

Comparator<Point> comp = new Comparator<Point>() {
    @Override
    public int compare(Point p1, Point p2) {
        return p2.y  == p1.y ? p2.x -p1.x : p2.y-p1.y;
    }
};
list.sort(comp);

edited Feb 15 '21 at 14:57

Burak

2,251
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answered Aug 23 '17 at 07:47

nagendra547

5,672
3
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43

1

looks promising.. I'll check and let you know. may be the order I have to change.. np man I'll up vote. there are some people just for this... – Ranju Aug 23 '17 at 08:57

Sort an ArrayList of Points in page line order

2 Answers2