show mail controller from any VC

show-mail-controller

#import <MessageUI/MessageUI.h>

- (void)showContactUsFromScreen:(UIViewController *)controller completion:(SFActionBlock)completion {
    if ( [MFMailComposeViewController canSendMail] ) {

        controller.view.userInteractionEnabled = NO;
        __weak UIViewController * weakController = controller;

        MFMailComposeViewController * mailComposeViewController = [[MFMailComposeViewController alloc] init];
        mailComposeViewController.mailComposeDelegate = self;
        [mailComposeViewController setSubject:NSLocalizedString(@"ContactUs.Subject", @"")];
        [mailComposeViewController setToRecipients:@[kContactUsEmail]];
        [mailComposeViewController.navigationBar setBarTintColor:[THStyles defaultBlueBackgroundColor]];
        [mailComposeViewController.navigationBar setTintColor:[THStyles defaultWhiteColor]];

        // Handle Mail Composer
        [[[[self rac_signalForSelector:@selector(mailComposeController:didFinishWithResult:error:)fromProtocol:@protocol(MFMailComposeViewControllerDelegate)] take:1]
            reduceEach:^id(MFMailComposeViewController * mailController, NSNumber * result, NSError * error){
                return result;
            }]
            subscribeNext:^(id result) {
                weakController.view.userInteractionEnabled = YES;
                [weakController dismissViewControllerAnimated:YES completion:nil];                
                if (completion) {
                    completion();
                }
            }];

        [controller presentViewController:mailComposeViewController animated:YES completion:nil];

    } else {

        [[UIPasteboard generalPasteboard] setString:kContactUsEmail];
        [SVProgressHUD showErrorWithStatus:NSLocalizedString(@"ContactUs.Error", @"")];
    }

    [SFStatisticsManager trackEvent:kStatsEventSettingsContactUs params:nil];
}