Ask for permissions on app launch.

app/src/main/java/at/bitfire/davdroid/ui/AccountsActivity.java

@@ -8,10 +8,12 @@
 
 package at.bitfire.davdroid.ui;
 
+import android.Manifest;
 import android.content.Intent;
 import android.os.Bundle;
 import android.support.design.widget.FloatingActionButton;
 import android.support.design.widget.NavigationView;
+import android.support.v4.app.ActivityCompat;
 import android.support.v4.app.FragmentTransaction;
 import android.support.v4.view.GravityCompat;
 import android.support.v4.widget.DrawerLayout;
@@ -67,6 +69,8 @@ public class AccountsActivity extends AppCompatActivity implements NavigationVie
                 Toast.makeText(this, "Server: " + serviceUrl.toString(), Toast.LENGTH_SHORT).show();
             }
         }
+
+        PermissionsActivity.requestAllPermissions(this);
     }
 
     @Override

app/src/main/java/at/bitfire/davdroid/ui/PermissionsActivity.java

@@ -9,6 +9,7 @@
 package at.bitfire.davdroid.ui;
 
 import android.Manifest;
+import android.app.Activity;
 import android.content.pm.PackageManager;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
@@ -23,6 +24,7 @@ import at.bitfire.davdroid.R;
 import at.bitfire.davdroid.resource.LocalTaskList;
 
 public class PermissionsActivity extends AppCompatActivity {
+    final static private int REQUEST_CODE_ASK_MULTIPLE_PERMISSIONS = 124;
 
     public static final String
             PERMISSION_READ_TASKS = "org.dmfs.permission.READ_TASKS",
@@ -96,4 +98,13 @@ public class PermissionsActivity extends AppCompatActivity {
         super.onRequestPermissionsResult(requestCode, permissions, grantResults);
         refresh();
     }
+
+    public static void requestAllPermissions(Activity activity) {
+        ActivityCompat.requestPermissions(activity, new String[] {
+                Manifest.permission.READ_CALENDAR,
+                Manifest.permission.WRITE_CALENDAR,
+                Manifest.permission.READ_CONTACTS,
+                Manifest.permission.WRITE_CONTACTS
+        }, REQUEST_CODE_ASK_MULTIPLE_PERMISSIONS);
+    }
 }