Add SwiftUI MiniBrowser
https://bugs.webkit.org/show_bug.cgi?id=218393
Patch by Adam Roben <aroben@apple.com> on 2020-11-03
Rubber-stamped by Tim Horton.
Using WKWebView in SwiftUI is pretty cumbersome today. At a minimum,
you need to wrap the WKWebView in a NS/UIViewRepresentable SwiftUI
view, but to react to any state changes in the WKWebView (e.g.,
-canGoBack changing from NO to YES) you need to bridge between
WKWebView's KVO and SwiftUI's use of Combine publishers or
ObservableObjects. Setting up WKWebView's various delegates has to
happen down inside the NS/UIViewRepresentable's Coordinator object.
And so on.
There have been some attempts at this in the past, e.g.:
https://medium.com/macoclock/how-to-use-webkit-webview-in-swiftui-4b944d04190a
https://medium.com/@mdyamin/swiftui-mastering-webview-5790e686833e
https://github.com/kylehickinson/SwiftUI-WebView
Someday it would be nice to provide an idiomatic SwiftUI API for
WebKit out of the box, like the new VideoPlayer API that wraps
AVPlayer.
This change provides a SwiftUI MiniBrowser implementation as well as a
very preliminary SwiftUI wrapper for WKWebView, originally authored by
James Savage. This only exposes a subset of the WKWebView API, and is
definitely not production ready yet, but will give us a place to
experiment with ways to make WebKit and SwiftUI work together better.
Here's James's description of the API:
> The initial version of this API is composed of two primary
> components: `WebView` and `WebViewState`. `WebView` conforms to
> `View`, and its usage is straight-forward. `WebViewState` is novel,
> and may not survive to the final API. It exists as a read-write
> handle on the rather large amount of state that a web view offers.
> This includes read-only access to properties about the current
> page (`title`, `url`, `hasOnlySecureContent`), navigations
> (`estimatedProgress`, `isLoading`), and back/forward history
> (`canGoBack`, `canGoForward`). It also offers imperative methods
> for navigation which map 1:1 with our existing Objective-C API.
>
> struct BrowserView : View {
> @StateObject var state = WebViewState(initialURL: URL(string: "https://apple.com")!)
> var body: some View {
> HStack {
> Text(verbatim: state.title ?? "Nothing Loaded")
> Text(verbatim: state.url ?? "--")
> WebView(state: state)
> }
> }
> }
>
> JavaScript dialogs are supported with both built-in behavior for all
> clients, and a customization point if desired. Clients can pass a
> `Binding<Dialog?>` to their `WebView` to disable the built-in
> display, and provide custom handling.
>
> Navigation policies can be customized using
> `webViewNavigationPolicy(onAction:onResponse:)` to provide custom
> decider for the action and response phases. These propagate via the
> environment, allowing them to be defined at an app, window, or
> individual view level.
>
> Future Directions
>
> To make `WebView` as declarative as possible, we're investigating
> how to make broader use of `Binding` for navigation. As a simple
> example, you could imagine if the `WebView`'s initializer took a
> `Binding<URL?>` for the current page. However, this design alone is
> too simplistic to model all states that the web view could be, so we
> will likely need to introduce a more complex type for the binding.
>
> Currently navigation policies are attached via `View` modifiers.
> This has the benefit that they can be installed at the root of an
> application, which is useful for a web browser where all tabs want
> to have uniform policies. Given the number of customization points
> in existing `WKWebView` delegates, this may fail to scale and lead
> to undesirable ergonomics. Another approach would to be just use a
> delegate protocol (a la DropDelegate:
> https://developer.apple.com/documentation/swiftui/dropdelegate).
>
> As a practical matter, we want to minimize the amount of work that
> adding new functionality to WebKit API incurs for engineers. While
> we could redefine every Objective-C type for SwiftUI, but this could
> lead to SwiftUI falling behind as our Objective-C API gets updated.
> We could use tools like `@dynamicMemberLookup` to automatically pull
> our Objective-C APIs over to Swift, however this could have
> undesirable impact our our ABI. There may be a better compromise we
> haven’t yet reached.
* MiniBrowserSwiftUI/Configurations/Base.xcconfig:
* MiniBrowserSwiftUI/Configurations/Debug.xcconfig:
* MiniBrowserSwiftUI/Configurations/MiniBrowserSwiftUI.xcconfig:
* MiniBrowserSwiftUI/Configurations/Release.xcconfig:
* MiniBrowserSwiftUI/Configurations/WebKit_SwiftUI.xcconfig:
* MiniBrowserSwiftUI/MiniBrowserSwiftUI.xcodeproj/project.pbxproj:
* MiniBrowserSwiftUI/MiniBrowserSwiftUI.xcodeproj/xcshareddata/xcschemes/MiniBrowserSwiftUI.xcscheme:
* MiniBrowserSwiftUI/MiniBrowserSwiftUI.xcodeproj/xcshareddata/xcschemes/_WebKit_SwiftUI.xcscheme:
Added the new project and its configuration. The project was generated
from Xcode's "Multiplatform App" template. There are two targets: the
MiniBrowserSwiftUI app, and the _WebKit_SwiftUI framework. Both are
cross-platform. The build settings were extracted out of the .pbxproj
into the .xcconfig files.
* MiniBrowserSwiftUI/Shared/Assets.xcassets/AccentColor.colorset/Contents.json:
* MiniBrowserSwiftUI/Shared/Assets.xcassets/AppIcon.appiconset/Contents.json:
* MiniBrowserSwiftUI/Shared/Assets.xcassets/Contents.json:
* MiniBrowserSwiftUI/Shared/Assets.xcassets/URLFieldBackground.colorset/Contents.json:
Defines a couple of colors and an empty icon for the app.
* MiniBrowserSwiftUI/iOS/Info.plist:
* MiniBrowserSwiftUI/macOS/Info.plist:
* MiniBrowserSwiftUI/macOS/macOS.entitlements:
* MiniBrowserSwiftUI/WebKit_SwiftUI/WebKit_SwiftUI-Info.plist: Added.
Added these files generated by Xcode. The only change was adding
com.apple.security.network.client to the entitlements so the browser
can connect to servers.
* MiniBrowserSwiftUI/Shared/BrowserApp.swift: Added. This is the entry
point of the app, and just sets up a BrowserScene.
* MiniBrowserSwiftUI/Shared/BrowserScene.swift: Added. This sets up
the browser's windows, each of which just contain a single BrowserTab.
On iOS we wrap the BrowserTab in a NavigationView so there will be
somewhere to show our toolbar buttons.
* MiniBrowserSwiftUI/Shared/BrowserTab.swift: Added. This is the heart
of the browser.
(BrowserTab.body): Sets up the WebView itself plus some toolbar items:
the back/forward buttons and URL field.
(BrowserTab.onNavigate(to:)): Callback called when the user presses
Return in the URL field.
(BrowserTab.decidePolicy(for:state:)): Callback called when the
WebView is about to navigate, similar to WKNavigationDelegate's
-webView:decidePolicyForNavigationAction:decisionHandler:.
(BrowserTab.makeExternalNavigationAlert(_:)): Displays an alert to let
the user decide whether to follow a URL that will open in some other
application.
(UserInput): Represents text typed in the URL field after determining
whether it is a URL or a search query.
(ExternalURLNavigation): Provides the data for the external navigation
alert.
(BrowserTab_Previews): Shows a canned BrowserTab in Xcode's preview
canvas.
* MiniBrowserSwiftUI/Shared/FoundationExtras.swift: Added. Provides a
few utility functions for URLs.
* MiniBrowserSwiftUI/Shared/URLField.swift: Added.
(URLField): The SwiftUI view you use directly. It contains a leading
glyph (e.g., a lock icon when viewing a secure page), a text field,
a trailing accessory view provided by the caller, and a progress bar.
It also supports callbacks to notify the caller when the text field
gains/loses focus and when the user has committed the text in the
field (e.g., by pressing Return).
(Background): The background view for the URLField, which defines both
the rounded rectangle shape for the field and the progress bar.
(URLField_Previews): Shows some canned URLFields in Xcode's preview
canvas.
* MiniBrowserSwiftUI/WebKit_SwiftUI/Dialog.swift: Added.
(Dialog): Represents a single JavaScript dialog (alert, confirm, or
prompt).
(DialogContainer): Provides the default UI shared by all JavaScript
dialog types.
* MiniBrowserSwiftUI/WebKit_SwiftUI/JavaScriptDialogs.swift: Added.
(JavaScriptAlert): Default UI for a JavaScript alert dialog.
(JavaScriptConfirm): Default UI for a JavaScript confirm dialog.
(JavaScriptPrompt): Default UI for a JavaScript prompt dialog.
* MiniBrowserSwiftUI/WebKit_SwiftUI/Navigation.swift: Added.
(View.webViewNavigationPolicy(onAction:)):
(View.webViewNavigationPolicy(onResponse:)):
(View.webViewNavigationPolicy(onAction:onResponse:)):
These let the application specify navigation policy logic for any
descendant WebViews in the view hierarchy, using SwiftUI's Environment
facility.
(NavigationAction): Idiomatic SwiftUI wrapper around
WKNavigationAction and its decision handler callback.
(NavigationResponse): Idiomatic SwiftUI wrapper around
WKNavigationResponse and its decision handler callback.
* MiniBrowserSwiftUI/WebKit_SwiftUI/SwiftUIExtras.swift: Added.
(Color.platformSeparator):
(Color.platformBackground):
Cross-platform wrappers around platform-specific colors.
* MiniBrowserSwiftUI/WebKit_SwiftUI/WebView.swift: Added.
(WebView): The heart of the SwiftUI API. You provide it a WebViewState
struct to represent and control its state (similar to AVFoundation's
VideoPlayer view controlled by AVPlayer). You can optionally provide a
Binding to be notified of the current JavaScript dialog that the web
content wishes to display. If you don't provide this binding, WebView
will present the dialog using default UI.
(WebView.dialogView): Configures the default dialog UI if the caller
doesn't want to handle dialogs on its own.
(_WebView): Internal view that bridges SwiftUI to WKWebView.
(Coordinator): Internal class that functions as the WKWebView's
WKNavigationDelegate and WKUIDelegate.
(Coordinator.webView(_:decidePolicyFor:preferences:decisionHandler:)):
Looks for a navigation decider in the view's environment and delegates
to it if found, otherwise allows all navigations.
(Coordinator.webView(_:runJavaScriptAlertPanelWithMessage:initiatedByFrame:completionHandler:)):
(Coordinator.webView(_:runJavaScriptConfirmPanelWithMessage:initiatedByFrame:completionHandler:)):
(Coordinator.webView(_:runJavaScriptTextInputPanelWithPrompt:defaultText:initiatedByFrame:completionHandler:)):
Passes the dialog information up to the WebView, which then decides
whether to present default UI itself or let the caller handle it.
* MiniBrowserSwiftUI/WebKit_SwiftUI/WebViewModifiers.swift: Added.
(View.webViewAllowsBackForwardNavigationGestures(_:)): Specifies
whether WebViews below this point in the view hierarchy should support
swipe gestures to navigate back/forward.
* MiniBrowserSwiftUI/WebKit_SwiftUI/WebViewState.swift: Added.
(WebViewState): Represents the state and actions of a WebView.
Conforms to ObservableObject so SwiftUI views can react to changes in
the WebViewState.
(WebViewState.webView(_:didChangeKeyPath:)): Detects when the
WKWebView's state has changed via KVO and reflects those through the
ObservableObject.objectWillChange mechanism so SwiftUI views will be
updated.
(WebViewState.canGoBack):
(WebViewState.canGoForward):
(WebViewState.title):
(WebViewState.url):
(WebViewState.isLoading):
(WebViewState.estimatedProgress):
(WebViewState.hasOnlySecureContent):
Wrappers around WKWebView properties.
(WebViewState.load(_:)):
(WebViewState.goBack):
(WebViewState.goForward):
(WebViewState.reload):
(WebViewState.stopLoading):
(WebViewState.createPDF(configuration:completion:)):
Wrappers around WKWebView methods.
Canonical link: https://commits.webkit.org/231173@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@269326 268f45cc-cd09-0410-ab3c-d52691b4dbfc
2020-11-03 20:16:14 +00:00
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//
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// Copyright (C) 2020 Apple Inc. All rights reserved.
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//
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions
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// are met:
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// 1. Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// 2. Redistributions in binary form must reproduce the above copyright
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// notice, this list of conditions and the following disclaimer in the
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// documentation and/or other materials provided with the distribution.
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//
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// THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
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// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
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// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
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// BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
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// THE POSSIBILITY OF SUCH DAMAGE.
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//
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#include "Base.xcconfig"
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ENABLE_NS_ASSERTIONS = NO
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DEBUG_INFORMATION_FORMAT = dwarf-with-dsym
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SWIFT_COMPILATION_MODE = wholemodule
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SWIFT_OPTIMIZATION_LEVEL = -O
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MTL_ENABLE_DEBUG_INFO = NO
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VALIDATE_PRODUCT = YES
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