Improve video prefetching (#17)

* Create base activity and add thumbnails to media picker

* Add checker to see if requested permission is inside the manifest

* Add faq parser with tests

* Add kpref testers and expose sp

* Test jitpack sample exclusion

* Test caching

* Improve glide caching

4 files changed, 48 insertions, 7 deletions

diff --git a/mediapicker/src/main/kotlin/ca/allanwang/kau/mediapicker/MediaItem.kt b/mediapicker/src/main/kotlin/ca/allanwang/kau/mediapicker/MediaItem.kt
index 3947809..b6f3721 100644
--- a/mediapicker/src/main/kotlin/ca/allanwang/kau/mediapicker/MediaItem.kt
+++ b/mediapicker/src/main/kotlin/ca/allanwang/kau/mediapicker/MediaItem.kt
@@ -40,6 +40,7 @@ class MediaItem(val data: MediaModel)
         super.bindView(holder, payloads)
         Glide.with(holder.itemView)
                 .load(data.data)
+                .applyMediaOptions(holder.itemView.context)
                 .listener(object : RequestListener<Drawable> {
                     override fun onLoadFailed(e: GlideException?, model: Any, target: Target<Drawable>, isFirstResource: Boolean): Boolean {
                         failedToLoad = true
diff --git a/mediapicker/src/main/kotlin/ca/allanwang/kau/mediapicker/MediaItemBasic.kt b/mediapicker/src/main/kotlin/ca/allanwang/kau/mediapicker/MediaItemBasic.kt
index 4fbe955..c28ed29 100644
--- a/mediapicker/src/main/kotlin/ca/allanwang/kau/mediapicker/MediaItemBasic.kt
+++ b/mediapicker/src/main/kotlin/ca/allanwang/kau/mediapicker/MediaItemBasic.kt
@@ -47,6 +47,7 @@ class MediaItemBasic(val data: MediaModel)
         super.bindView(holder, payloads)
         Glide.with(holder.itemView)
                 .load(data.data)
+                .applyMediaOptions(holder.itemView.context)
                 .listener(object : RequestListener<Drawable> {
                     override fun onLoadFailed(e: GlideException?, model: Any, target: Target<Drawable>, isFirstResource: Boolean): Boolean {
                         holder.image.setImageDrawable(MediaPickerCore.getErrorDrawable(holder.itemView.context))
diff --git a/mediapicker/src/main/kotlin/ca/allanwang/kau/mediapicker/MediaPickerBinder.kt b/mediapicker/src/main/kotlin/ca/allanwang/kau/mediapicker/MediaPickerBinder.kt
index bdd25ba..cb218fc 100644
--- a/mediapicker/src/main/kotlin/ca/allanwang/kau/mediapicker/MediaPickerBinder.kt
+++ b/mediapicker/src/main/kotlin/ca/allanwang/kau/mediapicker/MediaPickerBinder.kt
@@ -1,8 +1,12 @@
 package ca.allanwang.kau.mediapicker
 
 import android.app.Activity
+import android.content.Context
 import android.content.Intent
 import ca.allanwang.kau.utils.startActivityForResult
+import com.bumptech.glide.RequestBuilder
+import com.bumptech.glide.load.engine.DiskCacheStrategy
+import com.bumptech.glide.request.RequestOptions
 
 /**
  * Created by Allan Wang on 2017-07-21.
@@ -31,3 +35,6 @@ internal const val MEDIA_PICKER_RESULT = "media_picker_result"
 internal const val ANIMATION_DURATION = 200L
 internal const val ANIMATION_SCALE = 0.95f
 
+internal fun <T> RequestBuilder<T>.applyMediaOptions(context: Context)
+        = apply(RequestOptions().diskCacheStrategy(DiskCacheStrategy.RESOURCE).centerCrop().override(MediaPickerCore.viewSize(context)))
+
diff --git a/mediapicker/src/main/kotlin/ca/allanwang/kau/mediapicker/MediaPickerCore.kt b/mediapicker/src/main/kotlin/ca/allanwang/kau/mediapicker/MediaPickerCore.kt
index 255cec4..ee3481d 100644
--- a/mediapicker/src/main/kotlin/ca/allanwang/kau/mediapicker/MediaPickerCore.kt
+++ b/mediapicker/src/main/kotlin/ca/allanwang/kau/mediapicker/MediaPickerCore.kt
@@ -12,34 +12,42 @@ import android.provider.MediaStore
 import android.support.v4.app.LoaderManager
 import android.support.v4.content.CursorLoader
 import android.support.v4.content.Loader
-import android.support.v7.app.AppCompatActivity
 import android.support.v7.widget.GridLayoutManager
 import android.support.v7.widget.RecyclerView
 import ca.allanwang.kau.animators.FadeScaleAnimatorAdd
 import ca.allanwang.kau.animators.KauAnimator
+import ca.allanwang.kau.internal.KauBaseActivity
+import ca.allanwang.kau.kotlin.lazyContext
 import ca.allanwang.kau.permissions.kauRequestPermissions
 import ca.allanwang.kau.utils.dimenPixelSize
 import ca.allanwang.kau.utils.toast
+import com.bumptech.glide.Glide
 import com.mikepenz.fastadapter.IItem
 import com.mikepenz.fastadapter.commons.adapters.FastItemAdapter
 import com.mikepenz.google_material_typeface_library.GoogleMaterial
 import com.mikepenz.iconics.IconicsDrawable
+import org.jetbrains.anko.doAsync
+import java.util.concurrent.ExecutionException
+import java.util.concurrent.Future
 
 /**
  * Created by Allan Wang on 2017-07-23.
  *
  * Container for the main logic behind the both pickers
  */
-abstract class MediaPickerCore<T : IItem<*, *>>(val mediaType: MediaType) : AppCompatActivity(), LoaderManager.LoaderCallbacks<Cursor> {
+abstract class MediaPickerCore<T : IItem<*, *>>(
+        val mediaType: MediaType, val preload: Boolean = mediaType == MediaType.VIDEO
+) : KauBaseActivity(), LoaderManager.LoaderCallbacks<Cursor> {
 
     companion object {
+        val viewSize = lazyContext { computeViewSize(it) }
         /**
          * Given the dimensions of our device and a minimum image size,
          * Computer the optimal column count for our grid layout
          *
          * @return column count
          */
-        fun computeColumnCount(context: Context): Int {
+        private fun computeColumnCount(context: Context): Int {
             val minImageSizePx = context.dimenPixelSize(R.dimen.kau_image_minimum_size)
             val screenWidthPx = context.resources.displayMetrics.widthPixels
             return screenWidthPx / minImageSizePx
@@ -48,7 +56,7 @@ abstract class MediaPickerCore<T : IItem<*, *>>(val mediaType: MediaType) : AppC
         /**
          * Compute our resulting image size
          */
-        fun computeViewSize(context: Context): Int {
+        private fun computeViewSize(context: Context): Int {
             val screenWidthPx = context.resources.displayMetrics.widthPixels
             return screenWidthPx / computeColumnCount(context)
         }
@@ -84,6 +92,9 @@ abstract class MediaPickerCore<T : IItem<*, *>>(val mediaType: MediaType) : AppC
         const val CACHE_SIZE = 80
     }
 
+    private var hasPreloaded = false
+    private var prefetcher: Future<*>? = null
+
     val adapter: FastItemAdapter<T> = FastItemAdapter()
 
     /**
@@ -140,13 +151,30 @@ abstract class MediaPickerCore<T : IItem<*, *>>(val mediaType: MediaType) : AppC
             onStatusChange(false)
             return
         }
-        val items = mutableListOf<T>()
+        val models = mutableListOf<MediaModel>()
         do {
             val model = MediaModel(data)
             if (!shouldLoad(model)) continue
-            items.add(converter(model))
+            models.add(model)
         } while (data.moveToNext())
-        addItems(items)
+        addItems(models.map { converter(it) })
+        if (!hasPreloaded && preload) {
+            hasPreloaded = true
+            prefetcher = doAsync {
+                models.subList(0, Math.min(models.size, 50)).map { it.data }.forEach {
+                    val target = Glide.with(this@MediaPickerCore).load(it)
+                            .applyMediaOptions(this@MediaPickerCore)
+                            .submit()
+                    try {
+                        target.get()
+                    } catch (ignored: InterruptedException) {
+                    } catch (ignored: ExecutionException) {
+                    } finally {
+                        Glide.with(this@MediaPickerCore).clear(target)
+                    }
+                }
+            }
+        }
     }
 
     abstract fun converter(model: MediaModel): T
@@ -179,4 +207,8 @@ abstract class MediaPickerCore<T : IItem<*, *>>(val mediaType: MediaType) : AppC
 
     open fun onStatusChange(loaded: Boolean) {}
 
+    override fun onDestroy() {
+        prefetcher?.cancel(true)
+        super.onDestroy()
+    }
 }
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