use Picasso as a decoder for fullscreen SubsamplingScaleImageView images

app/build.gradle

@@ -58,6 +58,7 @@ dependencies {
     implementation 'com.google.vr:sdk-panowidget:1.150.0'
     implementation 'org.apache.sanselan:sanselan:0.97-incubator'
     implementation 'info.androidhive:imagefilters:1.0.7'
+    implementation 'com.squareup.picasso:picasso:2.71828'
 
     kapt "android.arch.persistence.room:compiler:1.1.1"
     implementation "android.arch.persistence.room:runtime:1.1.1"

app/proguard-rules.pro

@@ -1,3 +1,9 @@
 -keep class com.simplemobiletools.** { *; }
 -dontwarn com.simplemobiletools.**
 -dontwarn org.apache.**
+
+# Picasso
+-dontwarn javax.annotation.**
+-keepnames class okhttp3.internal.publicsuffix.PublicSuffixDatabase
+-dontwarn org.codehaus.mojo.animal_sniffer.*
+-dontwarn okhttp3.internal.platform.ConscryptPlatform

app/src/main/kotlin/com/simplemobiletools/gallery/activities/ViewPagerActivity.kt

@@ -77,7 +77,6 @@ class ViewPagerActivity : SimpleActivity(), ViewPager.OnPageChangeListener, View
     companion object {
         var screenWidth = 0
         var screenHeight = 0
-        var wasDecodedByGlide = false
     }
 
     override fun onCreate(savedInstanceState: Bundle?) {

app/src/main/kotlin/com/simplemobiletools/gallery/extensions/Activity.kt

@@ -61,7 +61,7 @@ fun Activity.launchCamera() {
 
 fun SimpleActivity.launchAbout() {
     val licenses = LICENSE_GLIDE or LICENSE_CROPPER or LICENSE_MULTISELECT or LICENSE_RTL or LICENSE_SUBSAMPLING or LICENSE_PATTERN or
-            LICENSE_REPRINT or LICENSE_GIF_DRAWABLE or LICENSE_PHOTOVIEW or LICENSE_EXOPLAYER or LICENSE_PANORAMA_VIEW or LICENSE_SANSELAN or LICENSE_FILTERS
+            LICENSE_REPRINT or LICENSE_GIF_DRAWABLE or LICENSE_PHOTOVIEW or LICENSE_PICASSO or LICENSE_EXOPLAYER or LICENSE_PANORAMA_VIEW or LICENSE_SANSELAN or LICENSE_FILTERS
 
     val faqItems = arrayListOf(
             FAQItem(R.string.faq_5_title_commons, R.string.faq_5_text_commons),

app/src/main/kotlin/com/simplemobiletools/gallery/fragments/PhotoFragment.kt

@@ -9,20 +9,14 @@ import android.graphics.Matrix
 import android.graphics.drawable.ColorDrawable
 import android.media.ExifInterface.*
 import android.net.Uri
-import android.os.AsyncTask
 import android.os.Bundle
 import android.os.Handler
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import com.bumptech.glide.Glide
-import com.bumptech.glide.load.DataSource
-import com.bumptech.glide.load.DecodeFormat
 import com.bumptech.glide.load.engine.DiskCacheStrategy
-import com.bumptech.glide.load.engine.GlideException
-import com.bumptech.glide.request.RequestListener
 import com.bumptech.glide.request.RequestOptions
-import com.bumptech.glide.request.target.Target
 import com.davemorrissey.labs.subscaleview.ImageSource
 import com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView
 import com.simplemobiletools.commons.extensions.*
@@ -33,11 +27,10 @@ import com.simplemobiletools.gallery.activities.PanoramaActivity
 import com.simplemobiletools.gallery.activities.PhotoActivity
 import com.simplemobiletools.gallery.activities.ViewPagerActivity
 import com.simplemobiletools.gallery.extensions.*
-import com.simplemobiletools.gallery.helpers.GlideRotateTransformation
-import com.simplemobiletools.gallery.helpers.MEDIUM
-import com.simplemobiletools.gallery.helpers.PATH
-import com.simplemobiletools.gallery.helpers.ROTATE_BY_ASPECT_RATIO
+import com.simplemobiletools.gallery.helpers.*
 import com.simplemobiletools.gallery.models.Medium
+import com.squareup.picasso.Callback
+import com.squareup.picasso.Picasso
 import it.sephiroth.android.library.exif2.ExifInterface
 import kotlinx.android.synthetic.main.pager_photo_item.view.*
 import org.apache.sanselan.common.byteSources.ByteSourceInputStream
@@ -48,12 +41,11 @@ import java.io.FileOutputStream
 
 class PhotoFragment : ViewPagerFragment() {
     private val DEFAULT_DOUBLE_TAP_ZOOM = 2f
-    private val ZOOMABLE_VIEW_LOAD_DELAY = 1000L
+    private val ZOOMABLE_VIEW_LOAD_DELAY = 500L
 
     private var isFragmentVisible = false
     private var isFullscreen = false
     private var wasInit = false
-    private var useHalfResolution = false
     private var isPanorama = false
     private var imageOrientation = -1
     private var gifDrawable: GifDrawable? = null
@@ -245,48 +237,19 @@ class PhotoFragment : ViewPagerFragment() {
 
     private fun loadBitmap(degrees: Int = 0) {
         if (degrees == 0) {
-            var targetWidth = if (ViewPagerActivity.screenWidth == 0) Target.SIZE_ORIGINAL else ViewPagerActivity.screenWidth
-            var targetHeight = if (ViewPagerActivity.screenHeight == 0) Target.SIZE_ORIGINAL else ViewPagerActivity.screenHeight
-            if (useHalfResolution) {
-                targetWidth /= 2
-                targetHeight /= 2
-            }
-
-            if (imageOrientation == ORIENTATION_ROTATE_90) {
-                targetWidth = targetHeight
-                targetHeight = Target.SIZE_ORIGINAL
-            }
-
-            val options = RequestOptions()
-                    .signature(medium.path.getFileSignature())
-                    .format(DecodeFormat.PREFER_ARGB_8888)
-                    .diskCacheStrategy(DiskCacheStrategy.RESOURCE)
-                    .override(targetWidth, targetHeight)
-
-            Glide.with(this)
-                    .asBitmap()
-                    .load(getPathToLoad(medium))
-                    .apply(options)
-                    .listener(object : RequestListener<Bitmap> {
-                        override fun onLoadFailed(e: GlideException?, model: Any?, target: Target<Bitmap>?, isFirstResource: Boolean): Boolean {
-                            if (!useHalfResolution && e?.rootCauses?.firstOrNull() is OutOfMemoryError) {
-                                useHalfResolution = true
-                                Handler().post {
-                                    if (activity?.isActivityDestroyed() == false) {
-                                        loadBitmap(degrees)
-                                    }
-                                }
-                            }
-                            return false
-                        }
-
-                        override fun onResourceReady(resource: Bitmap?, model: Any?, target: Target<Bitmap>?, dataSource: DataSource?, isFirstResource: Boolean): Boolean {
+            Picasso.get()
+                    .load(File(medium.path))
+                    .centerInside()
+                    .fit()
+                    .into(view.photo_view, object : Callback {
+                        override fun onSuccess() {
                             if (isFragmentVisible) {
                                 scheduleZoomableView()
                             }
-                            return false
                         }
-                    }).into(view.photo_view)
+
+                        override fun onError(e: Exception) {}
+                    })
         } else {
             val options = RequestOptions()
                     .diskCacheStrategy(DiskCacheStrategy.NONE)
@@ -311,23 +274,24 @@ class PhotoFragment : ViewPagerFragment() {
     private fun scheduleZoomableView() {
         loadZoomableViewHandler.removeCallbacksAndMessages(null)
         loadZoomableViewHandler.postDelayed({
-            if (isFragmentVisible && !context!!.config.replaceZoomableImages && medium.isImage() && view.subsampling_view.isGone()) {
+            if (isFragmentVisible && medium.isImage() && view.subsampling_view.isGone()) {
                 addZoomableView()
             }
         }, ZOOMABLE_VIEW_LOAD_DELAY)
     }
 
     private fun addZoomableView() {
-        ViewPagerActivity.wasDecodedByGlide = false
+        val rotation = degreesForRotation(imageOrientation)
         view.subsampling_view.apply {
+            setBitmapDecoderFactory { PicassoDecoder(medium.path, Picasso.get(), rotation) }
+            setRegionDecoderFactory { PicassoRegionDecoder() }
             maxScale = 10f
             beVisible()
             isQuickScaleEnabled = context.config.oneFingerZoom
             setResetScaleOnSizeChange(context.config.screenRotation != ROTATE_BY_ASPECT_RATIO)
             setImage(ImageSource.uri(getPathToLoad(medium)))
-            orientation = if (imageOrientation == -1) SubsamplingScaleImageView.ORIENTATION_USE_EXIF else degreesForRotation(imageOrientation)
+            orientation = rotation
             setEagerLoadingEnabled(false)
-            setExecutor(AsyncTask.SERIAL_EXECUTOR)
             setOnImageEventListener(object : SubsamplingScaleImageView.OnImageEventListener {
                 override fun onImageLoaded() {
                 }
@@ -400,8 +364,6 @@ class PhotoFragment : ViewPagerFragment() {
 
         return if (context == null || bitmapAspectRatio == screenAspectRatio) {
             DEFAULT_DOUBLE_TAP_ZOOM
-        } else if (ViewPagerActivity.wasDecodedByGlide) {
-            1f
         } else if (context!!.portrait && bitmapAspectRatio <= screenAspectRatio) {
             ViewPagerActivity.screenHeight / height.toFloat()
         } else if (context!!.portrait && bitmapAspectRatio > screenAspectRatio) {

app/src/main/kotlin/com/simplemobiletools/gallery/helpers/PicassoDecoder.kt

@@ -0,0 +1,21 @@
+package com.simplemobiletools.gallery.helpers
+
+import android.content.Context
+import android.graphics.Bitmap
+import android.net.Uri
+import com.davemorrissey.labs.subscaleview.decoder.ImageDecoder
+import com.squareup.picasso.MemoryPolicy
+import com.squareup.picasso.Picasso
+
+class PicassoDecoder(val tag: String, val picasso: Picasso, val degrees: Int) : ImageDecoder {
+
+    override fun decode(context: Context, uri: Uri): Bitmap {
+        return picasso
+                .load(uri)
+                .tag(tag)
+                .config(Bitmap.Config.ARGB_8888)
+                .memoryPolicy(MemoryPolicy.NO_CACHE)
+                .rotate(-degrees.toFloat())
+                .get()
+    }
+}

app/src/main/kotlin/com/simplemobiletools/gallery/helpers/PicassoRegionDecoder.kt

@@ -0,0 +1,33 @@
+package com.simplemobiletools.gallery.helpers
+
+import android.content.Context
+import android.graphics.*
+import android.net.Uri
+import com.davemorrissey.labs.subscaleview.decoder.ImageRegionDecoder
+
+class PicassoRegionDecoder : ImageRegionDecoder {
+    private var decoder: BitmapRegionDecoder? = null
+    private val decoderLock = Any()
+
+    override fun init(context: Context, uri: Uri): Point {
+        val inputStream = context.contentResolver.openInputStream(uri)
+        this.decoder = BitmapRegionDecoder.newInstance(inputStream, false)
+        return Point(this.decoder!!.width, this.decoder!!.height)
+    }
+
+    override fun decodeRegion(rect: Rect, sampleSize: Int): Bitmap {
+        synchronized(this.decoderLock) {
+            val options = BitmapFactory.Options()
+            options.inSampleSize = sampleSize
+            options.inPreferredConfig = Bitmap.Config.ARGB_8888
+            val bitmap = this.decoder!!.decodeRegion(rect, options)
+            return bitmap ?: throw RuntimeException("Region decoder returned null bitmap - image format may not be supported")
+        }
+    }
+
+    override fun isReady() = this.decoder != null && !this.decoder!!.isRecycled
+
+    override fun recycle() {
+        this.decoder!!.recycle()
+    }
+}