SubwayTooter-Android-App/sample_apng/src/main/java/jp/juggler/apng/sample/ActViewer.kt

package jp.juggler.apng.sample

import android.content.Context
import android.content.Intent
import android.graphics.Bitmap
import android.os.Bundle
import android.util.Log
import android.view.View
import android.widget.TextView
import jp.juggler.apng.ApngFrames
import jp.juggler.util.coroutine.AppDispatchers
import jp.juggler.util.coroutine.AsyncActivity
import jp.juggler.util.int
import jp.juggler.util.string
import kotlinx.coroutines.launch
import kotlinx.coroutines.withContext
import java.io.File
import java.io.FileOutputStream

class ActViewer : AsyncActivity() {

    companion object {
        const val TAG = "ActViewer"
        const val EXTRA_RES_ID = "res_id"
        const val EXTRA_CAPTION = "caption"

        fun open(context: Context, resId: Int, caption: String) {
            val intent = Intent(context, ActViewer::class.java)
            intent.putExtra(EXTRA_RES_ID, resId)
            intent.putExtra(EXTRA_CAPTION, caption)
            context.startActivity(intent)
        }
    }

    private lateinit var apngView: ApngView
    private lateinit var tvError: TextView

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        val resId = intent.int(EXTRA_RES_ID) ?: 0

        this.title = intent.string(EXTRA_CAPTION) ?: "?"

        setContentView(R.layout.act_apng_view)
        this.apngView = findViewById(R.id.apngView)
        this.tvError = findViewById(R.id.tvError)

        apngView.setOnLongClickListener {
            val apngFrames = apngView.apngFrames

            if (apngFrames != null) {
                save(apngFrames)
            }

            return@setOnLongClickListener true
        }

        launch {
            var apngFrames: ApngFrames? = null
            try {
                apngFrames = withContext(AppDispatchers.IO) {
                    try {
                        ApngFrames.parse(
                            1024f,
                            debug = true
                        ) { resources?.openRawResource(resId) }
                    } catch (ex: Throwable) {
                        ex.printStackTrace()
                        null
                    }
                }

                apngView.visibility = View.VISIBLE
                tvError.visibility = View.GONE
                apngView.apngFrames = apngFrames
                apngFrames = null
            } catch (ex: Throwable) {
                ex.printStackTrace()
                Log.e(ActList.TAG, "load error: ${ex.javaClass.simpleName} ${ex.message}")

                val message = "%s %s".format(ex.javaClass.simpleName, ex.message)
                if (!isDestroyed) {
                    apngView.visibility = View.GONE
                    tvError.visibility = View.VISIBLE
                    tvError.text = message
                }
            } finally {
                apngFrames?.dispose()
            }
        }
    }

    override fun onDestroy() {
        super.onDestroy()
        apngView.apngFrames?.dispose()
    }

    private fun save(apngFrames: ApngFrames) {
        val title = this.title

        launch(AppDispatchers.IO) {

            //deprecated in Android 10 (API level 29)
            //val dir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES)

            val dir = getExternalFilesDir(null)
            if (dir == null) {
                Log.e(TAG, "getExternalFilesDir(null) returns null.")
                return@launch
            }

            dir.mkdirs()
            if (!dir.exists()) {
                Log.e(TAG, "Directory not exists: $dir")
                return@launch
            }
            val frames = apngFrames.frames
            if (frames == null) {
                Log.e(TAG, "missing frames")
                return@launch
            }
            var i = 0
            for (f in frames) {
                Log.d(TAG, "$title[$i] timeWidth=${f.timeWidth}")
                val bitmap = f.bitmap

                FileOutputStream(File(dir, "${title}_$i.png")).use { fo ->
                    bitmap.compress(Bitmap.CompressFormat.PNG, 100, fo)
                }

                ++i
            }
        }
    }
}