allow croping and rotating the wallpaper before setting

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

@@ -75,7 +75,7 @@ class EditActivity : SimpleActivity(), CropImageView.OnCropImageCompleteListener
                 finish()
             }
         } else {
-            toast("${getString(R.string.image_croping_failed)} ${result.error.message}")
+            toast("${getString(R.string.image_editing_failed)} ${result.error.message}")
         }
     }
 

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

@@ -1,12 +1,77 @@
 package com.simplemobiletools.gallery.activities
 
+import android.app.Activity
+import android.app.WallpaperManager
+import android.graphics.Bitmap
+import android.net.Uri
 import android.os.Bundle
+import android.view.Menu
+import android.view.MenuItem
 import com.simplemobiletools.gallery.R
+import com.simplemobiletools.gallery.extensions.toast
+import com.theartofdev.edmodo.cropper.CropImageView
+import kotlinx.android.synthetic.main.activity_edit.*
 
-class SetWallpaperActivity : SimpleActivity() {
+class SetWallpaperActivity : SimpleActivity(), CropImageView.OnCropImageCompleteListener {
+    lateinit var uri: Uri
+    lateinit var wallpaperManager: WallpaperManager
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_set_wallpaper)
+
+        if (intent.data == null) {
+            toast(R.string.invalid_image_path)
+            finish()
+            return
+        }
+
+        uri = intent.data
+        if (uri.scheme != "file" && uri.scheme != "content") {
+            toast(R.string.unknown_file_location)
+            finish()
+            return
+        }
+
+        wallpaperManager = WallpaperManager.getInstance(applicationContext)
+        crop_image_view.apply {
+            guidelines = CropImageView.Guidelines.OFF
+            setOnCropImageCompleteListener(this@SetWallpaperActivity)
+            setImageUriAsync(intent.data)
+            setAspectRatio(wallpaperManager.desiredMinimumWidth, wallpaperManager.desiredMinimumHeight)
+        }
+    }
+
+    override fun onCreateOptionsMenu(menu: Menu?): Boolean {
+        menuInflater.inflate(R.menu.menu_set_wallpaper, menu)
+        return true
+    }
+
+    override fun onOptionsItemSelected(item: MenuItem): Boolean {
+        when (item.itemId) {
+            R.id.save -> {
+                crop_image_view.getCroppedImageAsync()
+                return true
+            }
+            R.id.rotate -> {
+                crop_image_view.rotateImage(90)
+                return true
+            }
+        }
+        return super.onOptionsItemSelected(item)
+    }
+
+    override fun onCropImageComplete(view: CropImageView?, result: CropImageView.CropResult) {
+        if (result.error == null) {
+            val bitmap = result.bitmap
+            val wantedHeight = wallpaperManager.desiredMinimumHeight
+            val ratio = wantedHeight / bitmap.height.toFloat()
+            val wantedWidth = (bitmap.width * ratio).toInt()
+            wallpaperManager.setBitmap(Bitmap.createScaledBitmap(bitmap, wantedWidth, wantedHeight, false))
+            setResult(Activity.RESULT_OK)
+            finish()
+        } else {
+            toast("${getString(R.string.image_editing_failed)}: ${result.error.message}")
+        }
     }
 }