Add support for multiple open items

Improve AppCoordinator code
Keep track of open items count in items navigation bar
Add ability to restore most recently opened item
Implement state restoration for open items
Allow switch to another open item via bar button menu
Use instant presenter to switch between open items
Maintain user order of open items
Add support for notes in open items
Validate open items when set on app launch
Observe open items for deletions
Add support for different open items per session

Zotero.xcodeproj/project.pbxproj

@@ -34,6 +34,7 @@
 		61C817F22A49B5D30085B1E6 /* CollectionResponseSpec.swift in Sources */ = {isa = PBXBuildFile; fileRef = B3B1EDEE250242E700D8BC1E /* CollectionResponseSpec.swift */; };
 		61FA14CE2B05081D00E7D423 /* TextConverter.swift in Sources */ = {isa = PBXBuildFile; fileRef = 61FA14CD2B05081D00E7D423 /* TextConverter.swift */; };
 		61FA14D02B08E24A00E7D423 /* ColorPickerStackView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 61FA14CF2B08E24A00E7D423 /* ColorPickerStackView.swift */; };
+		61E24DCC2ABB385E00D75F50 /* OpenItemsController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 61E24DCB2ABB385E00D75F50 /* OpenItemsController.swift */; };
 		B300B33324291C8D00C1FE1E /* RTranslatorMetadata.swift in Sources */ = {isa = PBXBuildFile; fileRef = B300B33224291C8D00C1FE1E /* RTranslatorMetadata.swift */; };
 		B300B3352429222B00C1FE1E /* TranslatorMetadata.swift in Sources */ = {isa = PBXBuildFile; fileRef = B300B3342429222B00C1FE1E /* TranslatorMetadata.swift */; };
 		B300B3362429234C00C1FE1E /* TranslatorMetadata.swift in Sources */ = {isa = PBXBuildFile; fileRef = B300B3342429222B00C1FE1E /* TranslatorMetadata.swift */; };
@@ -1240,6 +1241,7 @@
 		61BD13942A5831EF008A0704 /* TextKit1TextView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TextKit1TextView.swift; sourceTree = "<group>"; };
 		61FA14CD2B05081D00E7D423 /* TextConverter.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TextConverter.swift; sourceTree = "<group>"; };
 		61FA14CF2B08E24A00E7D423 /* ColorPickerStackView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ColorPickerStackView.swift; sourceTree = "<group>"; };
+		61E24DCB2ABB385E00D75F50 /* OpenItemsController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = OpenItemsController.swift; sourceTree = "<group>"; };
 		B300B33224291C8D00C1FE1E /* RTranslatorMetadata.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RTranslatorMetadata.swift; sourceTree = "<group>"; };
 		B300B3342429222B00C1FE1E /* TranslatorMetadata.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TranslatorMetadata.swift; sourceTree = "<group>"; };
 		B300B3372429254900C1FE1E /* SyncTranslatorsDbRequest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SyncTranslatorsDbRequest.swift; sourceTree = "<group>"; };
@@ -2246,6 +2248,7 @@
 				B305646C23FC051E003304F2 /* ObjectUserChangeObserver.swift */,
 				B34A9F6325BF1ABB007C9A4A /* PDFDocumentExporter.swift */,
 				B32B8A562B18A08900A9A741 /* PDFThumbnailController.swift */,
+				61E24DCB2ABB385E00D75F50 /* OpenItemsController.swift */,
 				B3C6D551261C9F2E0068B9FE /* PlaceholderTextViewDelegate.swift */,
 				B378F4CC242CD45700B88A05 /* RepoParserDelegate.swift */,
 				B305646A23FC051E003304F2 /* RItemLocaleController.swift */,
@@ -4943,6 +4946,7 @@
 				B36181EC24C96B0500B30D56 /* SearchableCollection.swift in Sources */,
 				B3830CDB255451AB00910FE0 /* TagPickerAction.swift in Sources */,
 				B3593F40241A61C700760E20 /* ItemCell.swift in Sources */,
+				61E24DCC2ABB385E00D75F50 /* OpenItemsController.swift in Sources */,
 				B305679023FC1D9B003304F2 /* CollectionDifference+Separated.swift in Sources */,
 				B3F6AA3A2AB30663005BC22E /* AnnotationTool.swift in Sources */,
 				B34ACC7A2514EAAB00040C17 /* AnnotationColorGenerator.swift in Sources */,

Zotero/Assets/en.lproj/Localizable.strings

@@ -142,6 +142,7 @@
 "items.generating_bib" = "Generating Bibliography";
 "items.creator_summary.and" = "%@ and %@";
 "items.creator_summary.etal" = "%@ et al.";
+"items.restore_open" = "Restore Open Items";
 
 "lookup.title" = "Enter ISBNs, DOls, PMIDs, arXiv IDs, or ADS Bibcodes to add to your library:";
 
@@ -541,3 +542,4 @@
 "accessibility.pdf.undo" = "Undo";
 "accessibility.pdf.toggle_annotation_toolbar" = "Toggle annotation toolbar";
 "accessibility.pdf.show_more_tools" = "Show more";
+"accessibility.pdf.open_items" = "Open Items";

Zotero/Controllers/Controllers.swift

@@ -310,6 +310,7 @@ final class UserControllers {
     let citationController: CitationController
     let webDavController: WebDavController
     let customUrlController: CustomURLController
+    let openItemsController: OpenItemsController
     private let isFirstLaunch: Bool
     private let lastBuildNumber: Int?
     private unowned let translatorsAndStylesController: TranslatorsAndStylesController
@@ -386,6 +387,7 @@ final class UserControllers {
         self.translatorsAndStylesController = controllers.translatorsAndStylesController
         self.idleTimerController = controllers.idleTimerController
         self.customUrlController = CustomURLController(dbStorage: dbStorage, fileStorage: controllers.fileStorage)
+        openItemsController = OpenItemsController(dbStorage: dbStorage, fileStorage: controllers.fileStorage)
         self.lastBuildNumber = controllers.lastBuildNumber
         self.disposeBag = DisposeBag()
     }

Zotero/Controllers/Database/Requests/ReadItemsDbRequest.swift

@@ -86,3 +86,15 @@ struct ReadItemsWithKeysDbRequest: DbResponseRequest {
         return database.objects(RItem.self).filter(.keys(self.keys, in: self.libraryId))
     }
 }
+
+struct ReadItemsWithKeysFromMultipleLibrariesDbRequest: DbResponseRequest {
+    typealias Response = Results<RItem>
+
+    let keysByLibraryIdentifier: [LibraryIdentifier: Set<String>]
+
+    var needsWrite: Bool { return false }
+
+    func process(in database: Realm) throws -> Results<RItem> {
+        database.objects(RItem.self).filter(.keysByLibraryIdentifier(keysByLibraryIdentifier))
+    }
+}