NavigationViewKit: a NavigationView extension library for SwiftUI

Sep 09, 2021 4 min read

NavigationViewKit

NavigationViewKit is a NavigationView extension library for SwiftUI.

For more detailed documentation and demo, please visit 用NavigationViewKit增强SwiftUI的导航视图

The extension follows several principles.

Non-disruptive

Any new feature does not affect the native functionality provided by Swiftui, especially if it does not affect the performance of Toolbar, NavigationLink in NavigationView

Be as easy to use as possible

Add new features with minimal code
SwiftUI native style

Extensions should be called in the same way as the native SwiftUI as much as possible

NavigationViewManager

Introduction

One of the biggest complaints from developers about NavigationView is that it does not support a convenient means of returning to the root view. There are two commonly used solutions.

Repackage the UINavigationController

A good wrapper can indeed use the many functions provided by UINavigationController, but it is very easy to conflict with the native methods in SwiftUI, so you can’t have both.
Use procedural `NavigationLink

Return the programmed NavigationLink (usually isActive) by undoing the root view. This means will limit the variety of NavigationLink options, plus is not conducive to implementation from non-view code.

NavigationViewManager is the navigation view manager provided in NavigationViewKit, it provides the following functions.

Can manage all the NavigationView in the application
Support to return the root view directly from any view under NavigationView by code
Jump to a new view via code from any view under NavigationView (no need to describe NavigationLink in the view)
Return to the root view via NotificatiionCenter for any NavigationView in the specified application
By NotificatiionCenter, let any NavigationView in the application jump to the new view
Support transition animation on and off

Register NavigationView

Since NavigationgViewManager supports multiple navigation views management, you need to register for each managed navigation view.

<div class="highlight highlight-source-swift position-relative" data-snippet-clipboard-copy-content="import NavigationViewKit
NavigationView {
List(0..

import NavigationViewKit
NavigationView {
            List(0..<10) { _ in
                NavigationLink("abc", destination: DetailView())
            }
        }
        .navigationViewManager(for: "nv1", afterBackDo: {print("back to root") })

navigationViewManager is a View extension, defined as follows.

Void = {}) -> some View
}
“>

extension View {
    public func navigationViewManager(for tag: String, afterBackDo cleanAction: @escaping () -> Void = {}) -> some View
}

for is the name (or tag) of the currently registered NavigationView, afterBackDo is the code segment executed when going to the root view.

The tag of each managed NavigationView in the application needs to be unique.

Returning to the root view from a view

In any sub-view of a registered NavigationView, the return to the root view can be achieved with the following code.

@Environment(\.navigationManager) var nvmanager         

Button("back to root view") {
    nvmanager.wrappedValue.popToRoot(tag:"nv1"){
          	 print("other back")
           }
}

popToRoot is defined as follows.

Void = {})
“>

func popToRoot(tag: String, animated: Bool = true, action: @escaping () -> Void = {})

tag is the registered Tag of the current NavigationView, animated sets whether to show the transition animation when returning to the root view, and action is the further after-back code segment. This code will be executed after the registration code segment (afterBackDo) and is mainly used to pass the data in the current view.

This can be done via the

@Environment(\.currentNaviationViewName) var tag

Get the registered Tag of the current NavigationView, so that the view can be reused in different NavigtionViews.

struct DetailView: View {
    @Environment(\.navigationManager) var nvmanager
    @Environment(\.currentNaviationViewName) var tag
    var body: some View {
        VStack {
            Button("back to root view") {
                if let tag = tag {
                    nvmanager.wrappedValue.popToRoot(tag:tag,animated: false) {
                        print("other back")
                    }
                }
            }
        }
    }
}

Using NotificationCenter to return to the root view

Since the main use of NavigationViewManager in my app is to handle Deep Link, the vast majority of the time it is not called in the view code. So NavigationViewManager provides a similar method based on NotificationCenter.

In the code using :

let backToRootItem = NavigationViewManager.BackToRootItem(tag: "nv1", animated: false, action: {})
NotificationCenter.default.post(name: .NavigationViewManagerBackToRoot, object: backToRootItem)

Returns the specified NavigationView to the root view.

Jump from a view to a new view

Use :

@Environment(\.navigationManager) var nvmanager

Button("go to new View"){
        nvmanager.wrappedValue.pushView(tag:"nv1",animated: true){
            Text("New View")
                .navigationTitle("new view")
        }
}

The definition of pushView is as follows.

func pushView<V: View>(tag: String, animated: Bool = true, @ViewBuilder view: () -> V)

tag is the registered Tag of NavigationView, animation sets whether to show the transition animation, view is the new view. The view supports all definitions native to SwiftUI, such as toolbar, navigationTitle, etc.

At the moment, when transition animation is enabled, title and toolbar will be shown after the transition animation, so the view is a little bit short. I will try to fix it in the future.

Use NotificationCenter to jump to new view

In the code.

let pushViewItem = NavigationViewManager.PushViewItem(tag: "nv1", animated: false) {
                    AnyView(
                        Text("New View")
                            .navigationTitle("第四级视图")
                    )
                }
NotificationCenter.default.post(name:.NavigationViewManagerPushView, object: pushViewItem)

At the moment, when transition animation is enabled, title and toolbar will be shown after the transition animation, so the view is a little bit short. I will try to fix it in the future.

Use NotificationCenter to jump to new view

In the code.

DoubleColoumnJustForPadNavigationViewStyle

DoubleColoumnJustForPadNavigationViewStyle is a modified version of DoubleColoumnNavigationViewStyle, its purpose is to improve the performance of DoubleColoumnNavigationViewStyle in landscape on iPhone Max when iPhone and iPad use the same set of code, and different from other iPhone models.

When iPhone Max is in landscape, the NavigationView will behave like iPad with double columns, which makes the application behave inconsistently on different iPhones.

When using DoubleColoumnJustForPadNavigationViewStyle, iPhone Max will still show StackNavigationViewStyle in landscape.

Usage.

NavigationView{
   ...
}
.navigationViewStyle(DoubleColoumnJustForPadNavigationViewStyle())

It can be used directly under swift 5.5

.navigationViewStyle(.columnsForPad)

TipOnceDoubleColumnNavigationViewStyle

The current DoubleColumnNavigationViewStyle behaves differently on iPad in both horizontal and vertical screens. When the screen is vertical, the left column is hidden by default, making it easy for new users to get confused.

TipOnceDoubleColumnNavigationViewStyle will show the left column above the right column to remind the user when the iPad is in vertical screen for the first time. This reminder will only happen once. If you rotate the orientation after the reminder, the reminder will not be triggered again when you enter the vertical screen again.

NavigationView{
   ...
}
.navigationViewStyle(TipOnceDoubleColumnNavigationViewStyle())

It can be used directly under swift 5.5

.navigationViewStyle(.tipColumns)

FixDoubleColumnNavigationViewStyle

In Health Notes, I want the iPad version to always keep two columns displayed no matter in landscape or portrait, and the left column cannot be hidden.

I previously used HStack set of two NavigationView to achieve this effect

Now, the above effect can be easily achieved by FixDoubleColumnNavigationViewStyle in NavigationViewKit directly.

NavigationView{
   ...
}
.navigationViewStyle(FixDoubleColumnNavigationViewStyle(widthForLandscape: 350, widthForPortrait:250))

And you can set the left column width separately for both landscape and portrait states.

For more detailed documentation and demo, please visit My Blog

GitHub

https://github.com/fatbobman/NavigationViewKit

NavigationViewKit: a NavigationView extension library for SwiftUI

NavigationViewKit

NavigationViewManager

Introduction

Register NavigationView

Returning to the root view from a view

Using NotificationCenter to return to the root view

Jump from a view to a new view

Use NotificationCenter to jump to new view

Use NotificationCenter to jump to new view

DoubleColoumnJustForPadNavigationViewStyle

TipOnceDoubleColumnNavigationViewStyle

FixDoubleColumnNavigationViewStyle

GitHub

Example project guide you schedules multiple thread for network requests in RxSwift

A Multiplatform iOS app to count stitches in crochet patterns

NavigationViewKit

NavigationViewManager

Introduction

Register NavigationView

Returning to the root view from a view

Using NotificationCenter to return to the root view

Jump from a view to a new view

Use NotificationCenter to jump to new view

Use NotificationCenter to jump to new view

DoubleColoumnJustForPadNavigationViewStyle

TipOnceDoubleColumnNavigationViewStyle

FixDoubleColumnNavigationViewStyle

GitHub

Example project guide you schedules multiple thread for network requests in RxSwift

A Multiplatform iOS app to count stitches in crochet patterns

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