54 lines
2.0 KiB
Kotlin
54 lines
2.0 KiB
Kotlin
package com.keylesspalace.tusky.pager
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import android.view.ViewGroup
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import androidx.fragment.app.Fragment
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import androidx.fragment.app.FragmentManager
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import androidx.fragment.app.FragmentStatePagerAdapter
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import com.keylesspalace.tusky.SharedElementTransitionListener
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import com.keylesspalace.tusky.entity.Attachment
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import com.keylesspalace.tusky.fragment.ViewMediaFragment
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import java.util.*
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class ImagePagerAdapter(
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fragmentManager: FragmentManager,
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private val attachments: List<Attachment>,
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private val initialPosition: Int
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) : FragmentStatePagerAdapter(fragmentManager), SharedElementTransitionListener {
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private var primaryItem: ViewMediaFragment? = null
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private var didTransition = false
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override fun setPrimaryItem(container: ViewGroup, position: Int, item: Any) {
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super.setPrimaryItem(container, position, item)
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this.primaryItem = item as ViewMediaFragment
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}
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override fun getItem(position: Int): Fragment {
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return if (position >= 0 && position < attachments.size) {
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// Fragment should not wait for or start transition if it already happened but we
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// instantiate the same fragment again, e.g. open the first photo, scroll to the
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// forth photo and then back to the first. The first fragment will trz to start the
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// transition and wait until it's over and it will never take place.
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ViewMediaFragment.newInstance(
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attachment = attachments[position],
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shouldStartPostponedTransition = !didTransition && position == initialPosition
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)
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} else {
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throw IllegalStateException()
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}
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}
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override fun getCount(): Int {
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return attachments.size
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}
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override fun getPageTitle(position: Int): CharSequence {
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return String.format(Locale.getDefault(), "%d/%d", position + 1, attachments.size)
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}
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override fun onTransitionEnd() {
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this.didTransition = true
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primaryItem?.onTransitionEnd()
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}
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}
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