remove some empty callbacks to avoid memory leaks

app/build.gradle

@@ -45,7 +45,7 @@ ext {
 }
 
 dependencies {
-    compile 'com.simplemobiletools:commons:2.37.12'
+    compile 'com.simplemobiletools:commons:2.38.0'
     compile 'com.davemorrissey.labs:subsampling-scale-image-view:3.7.2'
     compile 'com.theartofdev.edmodo:android-image-cropper:2.4.0'
     compile 'com.bignerdranch.android:recyclerview-multiselect:0.2'

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

@@ -60,7 +60,7 @@ class IncludedFoldersActivity : SimpleActivity() {
         FilePickerDialog(this, pickFile = false, showHidden = config.shouldShowHidden) {
             config.addIncludedFolder(it)
             updateIncludedFolders()
-            scanPath(it) {}
+            scanPath(it)
         }
     }
 }

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

@@ -209,7 +209,7 @@ class MainActivity : SimpleActivity(), DirectoryAdapter.DirOperationsListener {
         val newFolder = File(config.tempFolderPath)
         if (newFolder.exists() && newFolder.isDirectory) {
             if (newFolder.list()?.isEmpty() == true) {
-                deleteFileBg(newFolder, true) { }
+                deleteFileBg(newFolder, true)
             }
         }
         config.tempFolderPath = ""

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

@@ -347,7 +347,7 @@ class MediaActivity : SimpleActivity(), MediaAdapter.MediaOperationsListener {
     private fun deleteDirectoryIfEmpty() {
         val file = File(mPath)
         if (config.deleteEmptyFolders && !file.isDownloadsFolder() && file.isDirectory && file.listFiles()?.isEmpty() == true) {
-            deleteFile(file, true) {}
+            deleteFile(file, true)
         }
     }
 

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

@@ -59,14 +59,14 @@ open class PhotoVideoActivity : SimpleActivity(), ViewPagerFragment.FragmentList
         mIsFromGallery = intent.getBooleanExtra(IS_FROM_GALLERY, false)
 
         if (mUri!!.scheme == "file") {
-            scanPath(mUri!!.path) {}
+            scanPath(mUri!!.path)
             sendViewPagerIntent(mUri!!.path)
             finish()
             return
         } else {
             val path = applicationContext.getRealPathFromURI(mUri!!) ?: ""
             if (path != mUri.toString() && path.isNotEmpty()) {
-                scanPath(mUri!!.path) {}
+                scanPath(mUri!!.path)
                 sendViewPagerIntent(path)
                 finish()
                 return

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

@@ -194,7 +194,7 @@ class ViewPagerActivity : SimpleActivity(), ViewPager.OnPageChangeListener, View
         }
 
         reloadViewPager()
-        scanPath(mPath) {}
+        scanPath(mPath)
 
         if (config.darkBackground)
             view_pager.background = ColorDrawable(Color.BLACK)
@@ -525,10 +525,10 @@ class ViewPagerActivity : SimpleActivity(), ViewPager.OnPageChangeListener, View
                 }
 
                 if (tmpFile.length() > 0 && newFile.exists()) {
-                    deleteFile(newFile) {}
+                    deleteFile(newFile)
                 }
                 copyFile(tmpFile, newFile)
-                scanFile(newFile) {}
+                scanFile(newFile)
                 toast(R.string.file_saved)
 
                 if (config.keepLastModified) {
@@ -553,7 +553,7 @@ class ViewPagerActivity : SimpleActivity(), ViewPager.OnPageChangeListener, View
         } catch (e: Exception) {
             showErrorToast(e)
         } finally {
-            deleteFile(tmpFile) {}
+            deleteFile(tmpFile)
         }
     }
 
@@ -794,10 +794,10 @@ class ViewPagerActivity : SimpleActivity(), ViewPager.OnPageChangeListener, View
     private fun deleteDirectoryIfEmpty() {
         val file = File(mDirectory)
         if (config.deleteEmptyFolders && !file.isDownloadsFolder() && file.isDirectory && file.listFiles()?.isEmpty() == true) {
-            deleteFile(file, true) {}
+            deleteFile(file, true)
         }
 
-        scanPath(mDirectory) {}
+        scanPath(mDirectory)
     }
 
     private fun checkOrientation() {

app/src/main/kotlin/com/simplemobiletools/gallery/adapters/MediaAdapter.kt

@@ -173,7 +173,7 @@ class MediaAdapter(val activity: SimpleActivity, var media: MutableList<Medium>,
         Thread({
             getSelectedMedia().forEach {
                 val oldFile = File(it.path)
-                activity.toggleFileVisibility(oldFile, hide) {}
+                activity.toggleFileVisibility(oldFile, hide)
             }
             activity.runOnUiThread {
                 listener?.refreshItems()

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

@@ -116,14 +116,14 @@ fun SimpleActivity.addNoMedia(path: String, callback: () -> Unit) {
     }
 }
 
-fun SimpleActivity.removeNoMedia(path: String, callback: () -> Unit) {
+fun SimpleActivity.removeNoMedia(path: String, callback: (() -> Unit)? = null) {
     val file = File(path, NOMEDIA)
     deleteFile(file) {
-        callback()
+        callback?.invoke()
     }
 }
 
-fun SimpleActivity.toggleFileVisibility(oldFile: File, hide: Boolean, callback: (newFile: File) -> Unit) {
+fun SimpleActivity.toggleFileVisibility(oldFile: File, hide: Boolean, callback: ((newFile: File) -> Unit)? = null) {
     val path = oldFile.parent
     var filename = oldFile.name
     filename = if (hide) {
@@ -133,7 +133,7 @@ fun SimpleActivity.toggleFileVisibility(oldFile: File, hide: Boolean, callback:
     }
     val newFile = File(path, filename)
     renameFile(oldFile, newFile) {
-        callback(newFile)
+        callback?.invoke(newFile)
     }
 }
 

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

@@ -282,7 +282,7 @@ class MediaFetcher(val context: Context) {
             val isAlreadyAdded = curMedia.any { it.path == file.absolutePath }
             if (!isAlreadyAdded) {
                 curMedia.add(medium)
-                context.scanPath(file.absolutePath) {}
+                context.scanPath(file.absolutePath)
             }
         }
     }