add a check for writing to SD card for Android 5+

app/src/main/java/com/simplemobiletools/filemanager/Config.java

@@ -37,4 +37,12 @@ public class Config {
     public void setShowHidden(boolean show) {
         mPrefs.edit().putBoolean(Constants.SHOW_HIDDEN, show).apply();
     }
+
+    public String getTreeUri() {
+        return mPrefs.getString(Constants.TREE_URI, "");
+    }
+
+    public void setTreeUri(String uri) {
+        mPrefs.edit().putString(Constants.TREE_URI, uri).apply();
+    }
 }

app/src/main/java/com/simplemobiletools/filemanager/Constants.java

@@ -2,6 +2,7 @@ package com.simplemobiletools.filemanager;
 
 public class Constants {
     public static final String PATH = "path";
+    public static final String TREE_URI = "tree_uri";
 
     // shared preferences
     public static final String PREFS_KEY = "File Manager";

app/src/main/java/com/simplemobiletools/filemanager/Utils.kt

@@ -5,6 +5,7 @@ import android.content.Context
 import android.content.pm.PackageManager
 import android.support.v4.content.ContextCompat
 import android.widget.Toast
+import com.simplemobiletools.filepicker.extensions.getSDCardPath
 import java.util.regex.Pattern
 
 object Utils {
@@ -29,4 +30,8 @@ object Utils {
         val matcher = pattern.matcher(name)
         return matcher.matches()
     }
+
+    fun isPathOnSD(context: Context, path: String): Boolean {
+        return path.startsWith(context.getSDCardPath())
+    }
 }

app/src/main/java/com/simplemobiletools/filemanager/fragments/ItemsFragment.java

@@ -137,7 +137,7 @@ public class ItemsFragment extends android.support.v4.app.Fragment
         if (files != null) {
             for (File file : files) {
                 final String curPath = file.getAbsolutePath();
-                final String curName = Utils.getFilename(curPath);
+                final String curName = Utils.INSTANCE.getFilename(curPath);
                 if (!mShowHidden && curName.startsWith("."))
                     continue;
 
@@ -181,7 +181,7 @@ public class ItemsFragment extends android.support.v4.app.Fragment
         } else {
             final String path = item.getPath();
             final File file = new File(path);
-            String mimeType = MimeTypeMap.getSingleton().getMimeTypeFromExtension(Utils.getFileExtension(path));
+            String mimeType = MimeTypeMap.getSingleton().getMimeTypeFromExtension(Utils.INSTANCE.getFileExtension(path));
             if (mimeType == null)
                 mimeType = "text/plain";
 
@@ -192,7 +192,7 @@ public class ItemsFragment extends android.support.v4.app.Fragment
                 startActivity(intent);
             } catch (ActivityNotFoundException e) {
                 if (!tryGenericMimeType(intent, mimeType, file)) {
-                    Utils.showToast(getContext(), R.string.no_app_found);
+                    Utils.INSTANCE.showToast(getContext(), R.string.no_app_found);
                 }
             }
         }
@@ -302,7 +302,7 @@ public class ItemsFragment extends android.support.v4.app.Fragment
         }
 
         if (uris.isEmpty()) {
-            Utils.showToast(getContext(), R.string.no_files_selected);
+            Utils.INSTANCE.showToast(getContext(), R.string.no_files_selected);
             return;
         }
 
@@ -493,7 +493,7 @@ public class ItemsFragment extends android.support.v4.app.Fragment
 
     @Override
     public void copyFailed() {
-        Utils.showToast(getContext(), R.string.copy_failed);
+        Utils.INSTANCE.showToast(getContext(), R.string.copy_failed);
     }
 
     public interface ItemInteractionListener {

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

@@ -1,8 +1,11 @@
 package com.simplemobiletools.filemanager.activities
 
 import android.Manifest
+import android.annotation.TargetApi
+import android.app.Activity
 import android.content.Intent
 import android.content.pm.PackageManager
+import android.os.Build
 import android.os.Bundle
 import android.os.Handler
 import android.support.v4.app.ActivityCompat
@@ -14,11 +17,14 @@ import com.simplemobiletools.filemanager.Utils
 import com.simplemobiletools.filemanager.fragments.ItemsFragment
 import com.simplemobiletools.filepicker.dialogs.StoragePickerDialog
 import com.simplemobiletools.filepicker.extensions.getInternalStoragePath
+import com.simplemobiletools.filepicker.extensions.getSDCardPath
 import com.simplemobiletools.filepicker.models.FileDirItem
 import com.simplemobiletools.filepicker.views.Breadcrumbs
 import kotlinx.android.synthetic.main.activity_main.*
+import java.io.File
 
 class MainActivity : SimpleActivity(), ItemsFragment.ItemInteractionListener, Breadcrumbs.BreadcrumbsListener {
+    val OPEN_DOCUMENT_TREE = 1
     var mBasePath = getInternalStoragePath()
 
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -112,8 +118,7 @@ class MainActivity : SimpleActivity(), ItemsFragment.ItemInteractionListener, Br
         if (id == 0) {
             StoragePickerDialog(this@MainActivity, mBasePath, object : StoragePickerDialog.OnStoragePickerListener {
                 override fun onPick(pickedPath: String) {
-                    mBasePath = pickedPath
+                    changePath(pickedPath)
-                    openPath(pickedPath)
                 }
             })
         } else {
@@ -122,6 +127,41 @@ class MainActivity : SimpleActivity(), ItemsFragment.ItemInteractionListener, Br
         }
     }
 
+    fun changePath(pickedPath: String) {
+        if (checkStupidAndroidFiveSDCardWritePermission(pickedPath)) {
+            mBasePath = pickedPath
+            openPath(pickedPath)
+        }
+    }
+
+    fun checkStupidAndroidFiveSDCardWritePermission(pickedPath: String): Boolean {
+        val file = File(pickedPath)
+        return if (!file.canWrite() && Utils.isPathOnSD(applicationContext, pickedPath) && mConfig.treeUri.isEmpty()) {
+            val intent = Intent(Intent.ACTION_OPEN_DOCUMENT_TREE)
+            startActivityForResult(intent, OPEN_DOCUMENT_TREE)
+            false
+        } else
+            true
+    }
+
+    @TargetApi(Build.VERSION_CODES.KITKAT)
+    public override fun onActivityResult(requestCode: Int, resultCode: Int, resultData: Intent?) {
+        super.onActivityResult(requestCode, resultCode, resultData)
+        if (requestCode == OPEN_DOCUMENT_TREE) {
+            if (resultCode == Activity.RESULT_OK && resultData != null) {
+                val treeUri = resultData.data
+                mConfig.treeUri = resultData.data.toString()
+
+                val takeFlags = Intent.FLAG_GRANT_READ_URI_PERMISSION or Intent.FLAG_GRANT_WRITE_URI_PERMISSION
+                contentResolver.takePersistableUriPermission(treeUri, takeFlags)
+
+                changePath(getSDCardPath())
+            } else {
+                changePath(getInternalStoragePath())
+            }
+        }
+    }
+
     companion object {
         private val STORAGE_PERMISSION = 1
         private val BACK_PRESS_TIMEOUT = 5000