Schedule - Draw Android

package com.thieumao.test;

import android.graphics.Color;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.view.View;
import android.view.ViewGroup;
import android.widget.FrameLayout;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Random;

public class MainActivity extends AppCompatActivity {

    class ScheduleTime {
        private double startTime;
        private double endTime;
        ScheduleTime(double startTime, double endTime) {
            this.startTime = startTime;
            this.endTime = endTime;
        }

        public double getStartTime() {
            return startTime;
        }

        public void setStartTime(double startTime) {
            this.startTime = startTime;
        }

        public double getEndTime() {
            return endTime;
        }

        public void setEndTime(double endTime) {
            this.endTime = endTime;
        }
    }

    class ScheduleKey {
        private double startRange;
        private double endRange;
        ScheduleKey(double startTime, double endTime) {
            this.startRange = startTime;
            this.endRange = endTime;
        }

        public double getStartRange() {
            return startRange;
        }

        public void setStartRange(double startRange) {
            this.startRange = startRange;
        }

        public double getEndRange() {
            return endRange;
        }

        public void setEndRange(double endRange) {
            this.endRange = endRange;
        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        FrameLayout contentLayout = (FrameLayout) findViewById(R.id.content_layout);

        // stub
        List<ScheduleTime> schedules = Arrays.asList(
                new ScheduleTime(1, 2),
                new ScheduleTime(4, 5),
                new ScheduleTime(4.5, 5.5),
                new ScheduleTime(4.5, 5.5),
                new ScheduleTime(4.5, 5.5),
                new ScheduleTime(6, 23.5));

        Collections.sort(schedules, new Comparator<ScheduleTime>() {
            @Override
            public int compare(ScheduleTime schedule1, ScheduleTime schedule2) {
                double diff = schedule1.getStartTime() - schedule2.getStartTime();
                if (diff > 0) {
                    return 1;
                } else if (diff < 0) {
                    return -1;
                }
                return 0;
            }
        });

        for (ScheduleTime schedule : schedules) {
            ScheduleKey foundKey = null;
            for (ScheduleKey key : scheduleGroup.keySet()) {
                if (schedule.getStartTime() >= key.getStartRange() && schedule.getStartTime() < key.getEndRange()) {
                    foundKey = key;
                    break;
                }
            }

            if (foundKey != null) {
                foundKey.setStartRange(foundKey.getStartRange());
                foundKey.setEndRange(Math.max(schedule.getEndTime(), foundKey.getEndRange()));
                List<ScheduleTime> arr = scheduleGroup.get(foundKey);
                arr.add(schedule);
            } else {
                foundKey = new ScheduleKey(schedule.getStartTime(), schedule.getEndTime());
                List<ScheduleTime> arr = new ArrayList<>();
                arr.add(schedule);
                scheduleGroup.put(foundKey, arr);
            }
        }

        double paddingLeft = 200;// getResources().getDimensionPixelSize(R.dimen.content_layout_padding_left);
        DisplayMetrics metrics = new DisplayMetrics();

        getWindowManager().getDefaultDisplay().getMetrics(metrics);
        double width = metrics.widthPixels - paddingLeft;
        double height = 200;//getResources().getDimensionPixelSize(R.dimen.content_layout_height);
        for (List<MainActivity.ScheduleTime> arr : scheduleGroup.values()) {
            int w = (int)(width / arr.size());
            for (int i = 0; i < arr.size(); i++) {
                MainActivity.ScheduleTime schedule = arr.get(i);
                View v = new View(getApplicationContext());
                v.setBackgroundColor(getRandomColor());
                FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(w, (int)(height * (schedule.getEndTime() - schedule.getStartTime())));
                params.setMargins((int)(paddingLeft + i * w), (int)(schedule.getStartTime() * height), 0, 0);
                contentLayout.addView(v, params);
            }
        }

        ViewGroup.LayoutParams params = contentLayout.getLayoutParams();
        params.height = 24 * (int)height;
        contentLayout.setLayoutParams(params);
    }

    private Random random = new Random();
    private int getRandomColor() {
        int r = random.nextInt(255);
        int g = random.nextInt(255);
        int b = random.nextInt(255);
        return Color.rgb(r, g, b);
    }

    private Map<ScheduleKey, List<ScheduleTime>> scheduleGroup = new HashMap<>();
}