Incorporating top layout guide

[akashivskyy]

I am using a transparent UINavigationBar and UITextField. I want it to be 20px under the navigation bar, so I'm using the following commands:

[self.emailTextField mas_makeConstraints:^(MASConstraintMaker *make) {
    make.top.equalTo((self.view).mas_top).with.offset(20);
}];

However, my text field appears beneath the navigation bar, 20px from the top of the screen.

-- iOS 7 SPOILER ALERT --

In iOS 7 there is a topLayoutGuide property on UIViewController. How can I incorporate it using Masonry, so my text field appears under the navigation bar (84px from the top of the screen) both in iOS 7 with transparent navigation bar and in iOS 6?

I know that it can be done using NSLayoutConstraints. Taken from the documentation:

id topGuide = myViewController.topLayoutGuide;
// "button" is a UIButton object specified elsewhere
[myViewController.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:[topGuide]-20-[button]"]];

[akashivskyy]

I managed to do what I want using [viewController setEdgesForExtendedLayout:UIRectEdgeNone], but I'll leave this issue open as a feature request or at least to get an answer.

[cloudkite]

At the moment topLayoutGuide and bottomLayoutGuide are not supported directly. However you could try using the length property of topLayoutGuide:

[self.emailTextField mas_makeConstraints:^(MASConstraintMaker *make) {
    make.top.equalTo(self.view.mas_top).with.offset(self.topLayoutGuide.length + 20);
}];

if self.view is self.emailTextField's superview, then you could also write this as

[self.emailTextField mas_makeConstraints:^(MASConstraintMaker *make) {
    make.top.equalTo(@(self.topLayoutGuide.length + 20));
}];

Let me know if that works for you

[akashivskyy]

Yes, that kinda works, but I ended up by implementing my own version of those layout guides (for the sake of iOS 6 compatibility).

The problem with topLayoutGuide is that it is only correct when using only in several methods, but both examples that you provided work well.

[juri]

The problem with the .length workaround is that you often want a dynamic constraint. For example, if you have a view controller loaded from a XIB but want to add controls to the view, topLayoutGuide.length is 0 in -viewDidLoad and -viewWillAppear: but will go to 64 before viewDidAppear: if you are using a navigation bar. I usually want to add my subviews and their constraints before the view is on screen. Having direct support would be helpful.

[cloudkite]

@juri a dynamic solution was found in this issue #27 thanks

[juri]

Oh excellent, thanks and sorry for the noise!

[Pratik-Sodha]

topLayoutGuide deprecated in iOS 11, Use view.safeAreaLayoutGuide.topAnchor instead of topLayoutGuide.bottomAnchor_

        txtLink.snp.makeConstraints { (make) in
            make.top.equalTo(self.view.safeAreaLayoutGuide).inset(20)
        }