check kitkat sd permission before deleting from viewpager

app/src/main/java/com/simplemobiletools/gallery/activities/ViewPagerActivity.java

@@ -11,6 +11,8 @@ import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
 import android.provider.MediaStore;
+import android.support.annotation.RequiresApi;
+import android.support.v4.provider.DocumentFile;
 import android.support.v4.view.ViewPager;
 import android.support.v7.app.ActionBar;
 import android.view.Menu;
@@ -20,12 +22,14 @@ import android.view.View;
 import android.widget.RelativeLayout;
 
 import com.simplemobiletools.fileproperties.dialogs.PropertiesDialog;
+import com.simplemobiletools.gallery.Config;
 import com.simplemobiletools.gallery.Constants;
 import com.simplemobiletools.gallery.MyViewPager;
 import com.simplemobiletools.gallery.R;
 import com.simplemobiletools.gallery.Utils;
 import com.simplemobiletools.gallery.adapters.MyPagerAdapter;
 import com.simplemobiletools.gallery.dialogs.RenameItemDialog;
+import com.simplemobiletools.gallery.dialogs.WritePermissionDialog;
 import com.simplemobiletools.gallery.fragments.ViewPagerFragment;
 import com.simplemobiletools.gallery.models.Medium;
 
@@ -273,9 +277,30 @@ public class ViewPagerActivity extends SimpleActivity
 
         mIsUndoShown = false;
         mBeingDeleted = "";
+        boolean mWasFileDeleted = false;
 
         final File file = new File(mToBeDeleted);
-        if (file.delete()) {
+        if (Utils.Companion.needsStupidWritePermissions(this, mToBeDeleted)) {
+            if (Config.newInstance(this).getTreeUri().isEmpty()) {
+                new WritePermissionDialog(this, new WritePermissionDialog.OnWritePermissionListener() {
+                    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
+                    @Override
+                    public void onConfirmed() {
+                        final Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT_TREE);
+                        startActivityForResult(intent, Constants.OPEN_DOCUMENT_TREE);
+                    }
+                });
+            } else {
+                final DocumentFile document = Utils.Companion.getFileDocument(this, mToBeDeleted);
+                if (document.canWrite()) {
+                    mWasFileDeleted = document.delete();
+                }
+            }
+        } else {
+            mWasFileDeleted = file.delete();
+        }
+
+        if (mWasFileDeleted) {
             mBeingDeleted = mToBeDeleted;
             final String[] deletedPath = new String[]{mToBeDeleted};
             MediaScannerConnection.scanFile(getApplicationContext(), deletedPath, null, new MediaScannerConnection.OnScanCompletedListener() {
@@ -285,6 +310,7 @@ public class ViewPagerActivity extends SimpleActivity
                 }
             });
         }
+
         mToBeDeleted = "";
         mUndoBtn.setVisibility(View.GONE);
     }