metu.life-android/app/src/main/java/com/keylesspalace/tusky/pager/ImagePagerAdapter.kt

package com.keylesspalace.tusky.pager

import androidx.fragment.app.Fragment
import androidx.fragment.app.FragmentManager
import androidx.fragment.app.FragmentStatePagerAdapter

import com.keylesspalace.tusky.entity.Attachment
import com.keylesspalace.tusky.fragment.ViewMediaFragment
import java.lang.IllegalStateException

import java.util.Locale

class ImagePagerAdapter(
        fragmentManager: FragmentManager,
        private val attachments: List<Attachment>,
        private val initialPosition: Int
) : FragmentStatePagerAdapter(fragmentManager) {

    override fun getItem(position: Int): Fragment {
        return if (position >= 0 && position < attachments.size) {
            ViewMediaFragment.newInstance(attachments[position], position == initialPosition)
        } else {
            throw IllegalStateException()
        }
    }

    override fun getCount(): Int {
        return attachments.size
    }

    override fun getPageTitle(position: Int): CharSequence {
        return String.format(Locale.getDefault(), "%d/%d", position + 1, attachments.size)
    }
}