Seeing 5 windows opened, even though only tapped on 3 model links fro…

…m Safari

https://bugs.webkit.org/show_bug.cgi?id=261232
rdar://114172309

Reviewed by Mike Wyrzykowski.

On iOS the AR Quick Look feature is modal, which means only one preview
is open at a time. On visionOS the preview opens in a separate app, allowing
for the case where the user can tap many times and multiple windows open.
Furthermore, the communication with the system is a bit limited, which
can create a situation where more windows open than the user requested.

Limit this so that only one Quick Look can be downloading at a time. This
will still allow the user to open multiple models, but not get into this
confusing situation.

It isn't a great fix. A future change would be to keep a list of
active previews, with an upper limit, so that the user isn't blocked
from opening another file while a large file is being downloaded.

* Source/WebKit/UIProcess/Cocoa/SystemPreviewControllerCocoa.mm:
* Source/WebKit/UIProcess/SystemPreviewController.h:

Canonical link: https://commits.webkit.org/267708@main

Source/WebKit/UIProcess/Cocoa/SystemPreviewControllerCocoa.mm

@@ -366,6 +366,11 @@ - (void)completeLoad
 
 void SystemPreviewController::begin(const URL& url, const SecurityOriginData& topOrigin, const WebCore::SystemPreviewInfo& systemPreviewInfo, CompletionHandler<void()>&& completionHandler)
 {
+    if (m_state != State::Initial) {
+        RELEASE_LOG(SystemPreview, "SystemPreview didn't start because an existing preview is in progress");
+        return completionHandler();
+    }
+
     ASSERT(!m_qlPreviewController);
     if (m_qlPreviewController)
         return completionHandler();
@@ -409,7 +414,7 @@ - (void)completeLoad
     [presentingViewController presentViewController:m_qlPreviewController.get() animated:YES completion:nullptr];
 #endif
 
-    m_state = State::Began;
+    m_state = State::Initial;
 }
 
 void SystemPreviewController::loadStarted(const URL& localFileURL)
@@ -438,16 +443,16 @@ - (void)completeLoad
 #if PLATFORM(VISION)
     if ([getASVLaunchPreviewClass() respondsToSelector:@selector(launchPreviewApplicationWithURLs:completion:)])
         [getASVLaunchPreviewClass() launchPreviewApplicationWithURLs:localFileURLs() completion:^(NSError *error) { }];
+    m_state = State::Initial;
 #else
     if (m_qlPreviewControllerDataSource)
         [m_qlPreviewControllerDataSource finish:m_localFileURL];
+    m_state = State::Viewing;
 #endif
     releaseActivityTokenIfNecessary();
 
     if (m_testingCallback)
         m_testingCallback(true);
-
-    m_state = State::Succeeded;
 }
 
 void SystemPreviewController::loadFailed()
@@ -474,7 +479,7 @@ - (void)completeLoad
     if (m_testingCallback)
         m_testingCallback(false);
 
-    m_state = State::Failed;
+    m_state = State::Initial;
 }
 
 void SystemPreviewController::end()
@@ -488,7 +493,7 @@ - (void)completeLoad
     m_wkSystemPreviewDataTaskDelegate = nullptr;
 #endif
 
-    m_state = State::Ended;
+    m_state = State::Initial;
 }
 
 void SystemPreviewController::updateProgress(float progress)

Source/WebKit/UIProcess/SystemPreviewController.h

@@ -80,9 +80,7 @@ class SystemPreviewController : public CanMakeWeakPtr<SystemPreviewController> {
         Initial,
         Began,
         Loading,
-        Failed,
-        Succeeded,
-        Ended
+        Viewing
     };
 
     State m_state { State::Initial };