convert CopyTask to kotlin

app/src/main/java/com/simplemobiletools/filemanager/asynctasks/CopyTask.java

@@ -1,89 +0,0 @@
-package com.simplemobiletools.filemanager.asynctasks;
-
-import android.os.AsyncTask;
-import android.support.v4.util.Pair;
-import android.util.Log;
-
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
-import java.lang.ref.WeakReference;
-import java.util.List;
-
-public class CopyTask extends AsyncTask<Pair<List<File>, File>, Void, Boolean> {
-    private static final String TAG = CopyTask.class.getSimpleName();
-
-    private static WeakReference<CopyListener> mListener;
-    private static File destinationDir;
-
-    public CopyTask(CopyListener listener) {
-        mListener = new WeakReference<>(listener);
-    }
-
-    @Override
-    protected Boolean doInBackground(Pair<List<File>, File>... params) {
-        final Pair<List<File>, File> pair = params[0];
-        final List<File> files = pair.first;
-        for (File file : files) {
-            try {
-                destinationDir = new File(pair.second, file.getName());
-                copy(file, destinationDir);
-                return true;
-            } catch (Exception e) {
-                Log.e(TAG, "copy " + e);
-            }
-        }
-        return false;
-    }
-
-    private void copy(File source, File destination) throws Exception {
-        if (source.isDirectory()) {
-            if (!destination.exists() && !destination.mkdirs()) {
-                throw new IOException("Could not create dir " + destination.getAbsolutePath());
-            }
-
-            final String[] children = source.list();
-            for (String child : children) {
-                copy(new File(source, child), new File(destination, child));
-            }
-        } else {
-            final File directory = destination.getParentFile();
-            if (directory != null && !directory.exists() && !directory.mkdirs()) {
-                throw new IOException("Could not create dir " + directory.getAbsolutePath());
-            }
-
-            final InputStream in = new FileInputStream(source);
-            final OutputStream out = new FileOutputStream(destination);
-
-            final byte[] buf = new byte[1024];
-            int len;
-            while ((len = in.read(buf)) > 0) {
-                out.write(buf, 0, len);
-            }
-            in.close();
-            out.close();
-        }
-    }
-
-    @Override
-    protected void onPostExecute(Boolean success) {
-        final CopyListener listener = mListener.get();
-        if (listener == null)
-            return;
-
-        if (success) {
-            listener.copySucceeded(destinationDir);
-        } else {
-            listener.copyFailed();
-        }
-    }
-
-    public interface CopyListener {
-        void copySucceeded(File destinationDir);
-
-        void copyFailed();
-    }
-}

app/src/main/java/com/simplemobiletools/filemanager/asynctasks/CopyTask.kt

@@ -0,0 +1,83 @@
+package com.simplemobiletools.filemanager.asynctasks
+
+import android.os.AsyncTask
+import android.support.v4.util.Pair
+import android.util.Log
+import java.io.File
+import java.io.FileInputStream
+import java.io.FileOutputStream
+import java.io.IOException
+import java.lang.ref.WeakReference
+
+class CopyTask(listener: CopyTask.CopyListener) : AsyncTask<Pair<List<File>, File>, Void, Boolean>() {
+    private val TAG = CopyTask::class.java.simpleName
+    private var mListener: WeakReference<CopyListener>? = null
+    private var destinationDir: File? = null
+
+    init {
+        mListener = WeakReference(listener)
+    }
+
+    override fun doInBackground(vararg params: Pair<List<File>, File>): Boolean? {
+        val pair = params[0]
+        val files = pair.first
+        for (file in files) {
+            try {
+                destinationDir = File(pair.second, file.name)
+                copy(file, destinationDir!!)
+                return true
+            } catch (e: Exception) {
+                Log.e(TAG, "copy " + e)
+            }
+
+        }
+        return false
+    }
+
+    @Throws(Exception::class)
+    private fun copy(source: File, destination: File) {
+        if (source.isDirectory) {
+            if (!destination.exists() && !destination.mkdirs()) {
+                throw IOException("Could not create dir " + destination.absolutePath)
+            }
+
+            val children = source.list()
+            for (child in children) {
+                copy(File(source, child), File(destination, child))
+            }
+        } else {
+            val directory = destination.parentFile
+            if (!directory.exists() && !directory.mkdirs()) {
+                throw IOException("Could not create dir " + directory.absolutePath)
+            }
+
+            val inputStream = FileInputStream(source)
+            val out = FileOutputStream(destination)
+
+            val buf = ByteArray(1024)
+            var len: Int
+            while (true) {
+                len = inputStream.read(buf)
+                if (len <= 0)
+                    break
+                out.write(buf, 0, len)
+            }
+        }
+    }
+
+    override fun onPostExecute(success: Boolean) {
+        val listener = mListener?.get() ?: return
+
+        if (success) {
+            listener.copySucceeded(destinationDir!!)
+        } else {
+            listener.copyFailed()
+        }
+    }
+
+    interface CopyListener {
+        fun copySucceeded(destinationDir: File)
+
+        fun copyFailed()
+    }
+}