fix #1293, rely on ContentObserver for showing new files quicker

app/src/main/kotlin/com/simplemobiletools/gallery/pro/activities/MainActivity.kt

@@ -147,6 +147,7 @@ class MainActivity : SimpleActivity(), DirectoryOperationsListener {
         }
 
         updateWidgets()
+        registerFileUpdateListener()
     }
 
     override fun onStart() {
@@ -239,6 +240,7 @@ class MainActivity : SimpleActivity(), DirectoryOperationsListener {
             config.tempSkipDeleteConfirmation = false
             mTempShowHiddenHandler.removeCallbacksAndMessages(null)
             removeTempFolder()
+            unregisterFileUpdateListener()
 
             if (!config.showAll) {
                 GalleryDatabase.destroyInstance()

app/src/main/kotlin/com/simplemobiletools/gallery/pro/activities/MediaActivity.kt

@@ -108,6 +108,7 @@ class MediaActivity : SimpleActivity(), MediaOperationsListener {
 
         if (mShowAll) {
             supportActionBar?.setDisplayHomeAsUpEnabled(false)
+            registerFileUpdateListener()
         }
 
         media_empty_text.setOnClickListener {
@@ -193,6 +194,7 @@ class MediaActivity : SimpleActivity(), MediaOperationsListener {
         if (config.showAll && !isChangingConfigurations) {
             config.temporarilyShowHidden = false
             config.tempSkipDeleteConfirmation = false
+            unregisterFileUpdateListener()
             GalleryDatabase.destroyInstance()
         }
 

app/src/main/kotlin/com/simplemobiletools/gallery/pro/activities/SimpleActivity.kt

@@ -1,13 +1,28 @@
 package com.simplemobiletools.gallery.pro.activities
 
 import android.annotation.SuppressLint
+import android.database.ContentObserver
+import android.net.Uri
+import android.provider.MediaStore
 import android.view.WindowManager
 import com.simplemobiletools.commons.activities.BaseSimpleActivity
+import com.simplemobiletools.commons.extensions.getRealPathFromURI
 import com.simplemobiletools.commons.helpers.isPiePlus
 import com.simplemobiletools.gallery.pro.R
+import com.simplemobiletools.gallery.pro.extensions.addPathToDB
 import com.simplemobiletools.gallery.pro.extensions.config
 
 open class SimpleActivity : BaseSimpleActivity() {
+    val observer = object : ContentObserver(null) {
+        override fun onChange(selfChange: Boolean, uri: Uri) {
+            super.onChange(selfChange, uri)
+            val path = getRealPathFromURI(uri)
+            if (path != null) {
+                addPathToDB(path)
+            }
+        }
+    }
+
     override fun getAppIconIDs() = arrayListOf(
             R.mipmap.ic_launcher_red,
             R.mipmap.ic_launcher_pink,
@@ -46,4 +61,19 @@ open class SimpleActivity : BaseSimpleActivity() {
             }
         }
     }
+
+    protected fun registerFileUpdateListener() {
+        try {
+            contentResolver.registerContentObserver(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, true, observer)
+            contentResolver.registerContentObserver(MediaStore.Video.Media.EXTERNAL_CONTENT_URI, true, observer)
+        } catch (ignored: Exception) {
+        }
+    }
+
+    protected fun unregisterFileUpdateListener() {
+        try {
+            contentResolver.unregisterContentObserver(observer)
+        } catch (ignored: Exception) {
+        }
+    }
 }

app/src/main/kotlin/com/simplemobiletools/gallery/pro/extensions/Context.kt

@@ -698,3 +698,19 @@ fun Context.parseFileChannel(path: String, fc: FileChannel, level: Int, start: L
     } catch (ignored: Exception) {
     }
 }
+
+fun Context.addPathToDB(path: String) {
+    Thread {
+        val type = when {
+            path.isVideoFast() -> TYPE_VIDEOS
+            path.isGif() -> TYPE_GIFS
+            path.isRawFast() -> TYPE_RAWS
+            path.isSvg() -> TYPE_SVGS
+            else -> TYPE_IMAGES
+        }
+
+        val medium = Medium(null, path.getFilenameFromPath(), path, path.getParentPath(), System.currentTimeMillis(), System.currentTimeMillis(),
+                File(path).length(), type, 0, false, 0L)
+        galleryDB.MediumDao().insert(medium)
+    }.start()
+}

app/src/main/kotlin/com/simplemobiletools/gallery/pro/receivers/RefreshMediaReceiver.kt

@@ -3,29 +3,12 @@ package com.simplemobiletools.gallery.pro.receivers
 import android.content.BroadcastReceiver
 import android.content.Context
 import android.content.Intent
-import com.simplemobiletools.commons.extensions.*
 import com.simplemobiletools.commons.helpers.REFRESH_PATH
-import com.simplemobiletools.gallery.pro.extensions.galleryDB
-import com.simplemobiletools.gallery.pro.helpers.*
-import com.simplemobiletools.gallery.pro.models.Medium
-import java.io.File
+import com.simplemobiletools.gallery.pro.extensions.addPathToDB
 
 class RefreshMediaReceiver : BroadcastReceiver() {
     override fun onReceive(context: Context, intent: Intent) {
         val path = intent.getStringExtra(REFRESH_PATH) ?: return
-
-        Thread {
-            val medium = Medium(null, path.getFilenameFromPath(), path, path.getParentPath(), System.currentTimeMillis(), System.currentTimeMillis(),
-                    File(path).length(), getFileType(path), 0, false, 0L)
-            context.galleryDB.MediumDao().insert(medium)
-        }.start()
-    }
-
-    private fun getFileType(path: String) = when {
-        path.isVideoFast() -> TYPE_VIDEOS
-        path.isGif() -> TYPE_GIFS
-        path.isRawFast() -> TYPE_RAWS
-        path.isSvg() -> TYPE_SVGS
-        else -> TYPE_IMAGES
+        context.addPathToDB(path)
     }
 }