feat: add preview tabs (#245)

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- Preview tabs: single-click opens a temporary preview tab, double-click or editing promotes it to a permanent tab
 - Import plugin system: SQL import extracted into a `.tableplugin` bundle, matching the export plugin architecture
 - `ImportFormatPlugin` protocol in TableProPluginKit for building custom import format plugins
 - SQLImportPlugin as the first import format plugin (SQL files and .gz compressed SQL)

TablePro.xcodeproj/project.pbxproj

@@ -1735,9 +1735,9 @@
 				DEVELOPMENT_TEAM = D7HJ5TFYCU;
 				DYLIB_COMPATIBILITY_VERSION = 1;
 				DYLIB_CURRENT_VERSION = 1;
+				DYLIB_INSTALL_NAME_BASE = "@rpath";
 				GENERATE_INFOPLIST_FILE = YES;
 				INFOPLIST_FILE = "";
-				DYLIB_INSTALL_NAME_BASE = "@rpath";
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				LD_RUNPATH_SEARCH_PATHS = "@executable_path/../Frameworks";
 				MACOSX_DEPLOYMENT_TARGET = 14.0;
@@ -1761,9 +1761,9 @@
 				DEVELOPMENT_TEAM = D7HJ5TFYCU;
 				DYLIB_COMPATIBILITY_VERSION = 1;
 				DYLIB_CURRENT_VERSION = 1;
+				DYLIB_INSTALL_NAME_BASE = "@rpath";
 				GENERATE_INFOPLIST_FILE = YES;
 				INFOPLIST_FILE = "";
-				DYLIB_INSTALL_NAME_BASE = "@rpath";
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				LD_RUNPATH_SEARCH_PATHS = "@executable_path/../Frameworks";
 				MACOSX_DEPLOYMENT_TARGET = 14.0;
@@ -2475,51 +2475,51 @@
 			};
 			name = Debug;
 		};
-		5A86F000600000000 /* Debug */ = {
+		5A86E000700000000 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				CODE_SIGN_STYLE = Automatic;
 				COMBINE_HIDPI_IMAGES = YES;
 				CURRENT_PROJECT_VERSION = 1;
 				DEVELOPMENT_TEAM = D7HJ5TFYCU;
 				GENERATE_INFOPLIST_FILE = YES;
-				INFOPLIST_FILE = Plugins/SQLImportPlugin/Info.plist;
-				INFOPLIST_KEY_NSPrincipalClass = "$(PRODUCT_MODULE_NAME).SQLImportPlugin";
+				INFOPLIST_FILE = Plugins/MQLExportPlugin/Info.plist;
+				INFOPLIST_KEY_NSPrincipalClass = "$(PRODUCT_MODULE_NAME).MQLExportPlugin";
 				LD_RUNPATH_SEARCH_PATHS = "@executable_path/../Frameworks";
 				MACOSX_DEPLOYMENT_TARGET = 14.0;
 				MARKETING_VERSION = 1.0;
-				PRODUCT_BUNDLE_IDENTIFIER = com.TablePro.SQLImportPlugin;
+				PRODUCT_BUNDLE_IDENTIFIER = com.TablePro.MQLExportPlugin;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SDKROOT = macosx;
 				SKIP_INSTALL = YES;
 				SUPPORTED_PLATFORMS = macosx;
 				SWIFT_VERSION = 5.9;
 				WRAPPER_EXTENSION = tableplugin;
 			};
-			name = Debug;
+			name = Release;
 		};
-		5A86E000700000000 /* Release */ = {
+		5A86F000600000000 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				CODE_SIGN_STYLE = Automatic;
 				COMBINE_HIDPI_IMAGES = YES;
 				CURRENT_PROJECT_VERSION = 1;
 				DEVELOPMENT_TEAM = D7HJ5TFYCU;
 				GENERATE_INFOPLIST_FILE = YES;
-				INFOPLIST_FILE = Plugins/MQLExportPlugin/Info.plist;
-				INFOPLIST_KEY_NSPrincipalClass = "$(PRODUCT_MODULE_NAME).MQLExportPlugin";
+				INFOPLIST_FILE = Plugins/SQLImportPlugin/Info.plist;
+				INFOPLIST_KEY_NSPrincipalClass = "$(PRODUCT_MODULE_NAME).SQLImportPlugin";
 				LD_RUNPATH_SEARCH_PATHS = "@executable_path/../Frameworks";
 				MACOSX_DEPLOYMENT_TARGET = 14.0;
 				MARKETING_VERSION = 1.0;
-				PRODUCT_BUNDLE_IDENTIFIER = com.TablePro.MQLExportPlugin;
+				PRODUCT_BUNDLE_IDENTIFIER = com.TablePro.SQLImportPlugin;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SDKROOT = macosx;
 				SKIP_INSTALL = YES;
 				SUPPORTED_PLATFORMS = macosx;
 				SWIFT_VERSION = 5.9;
 				WRAPPER_EXTENSION = tableplugin;
 			};
-			name = Release;
+			name = Debug;
 		};
 		5A86F000700000000 /* Release */ = {
 			isa = XCBuildConfiguration;

TablePro/AppDelegate.swift

@@ -519,6 +519,7 @@ class AppDelegate: NSObject, NSApplicationDelegate {
         for window in NSApp.windows where isMainWindow(window) {
             let hasActiveSession = DatabaseManager.shared.activeSessions.values.contains {
                 window.subtitle == $0.connection.name
+                    || window.subtitle == "\($0.connection.name) — Preview"
             }
             if !hasActiveSession {
                 window.close()

TablePro/ContentView.swift

@@ -187,7 +187,11 @@ struct ContentView: View {
                 // for the brief window before registration completes.
                 let isOurWindow = WindowLifecycleMonitor.shared.windows(for: connectionId)
                     .contains(where: { $0 === notificationWindow })
-                    || notificationWindow.subtitle == currentSession?.connection.name
+                    || {
+                        guard let name = currentSession?.connection.name, !name.isEmpty else { return false }
+                        return notificationWindow.subtitle == name
+                            || notificationWindow.subtitle == "\(name) — Preview"
+                    }()
                 guard isOurWindow else { return }
 
                 if let session = DatabaseManager.shared.activeSessions[connectionId] {
@@ -219,6 +223,24 @@ struct ContentView: View {
                         onShowAllTables: {
                             showAllTablesMetadata()
                         },
+                        onDoubleClick: { table in
+                            let isView = table.type == .view
+                            if let preview = WindowLifecycleMonitor.shared.previewWindow(for: currentSession.connection.id),
+                               let previewCoordinator = MainContentCoordinator.coordinator(for: preview.windowId) {
+                                // If the preview tab shows this table, promote it
+                                if previewCoordinator.tabManager.selectedTab?.tableName == table.name {
+                                    previewCoordinator.promotePreviewTab()
+                                } else {
+                                    // Preview shows a different table — promote it first, then open this table permanently
+                                    previewCoordinator.promotePreviewTab()
+                                    sessionState.coordinator.openTableTab(table.name, isView: isView)
+                                }
+                            } else {
+                                // No preview tab — promote current if it's a preview, otherwise open permanently
+                                sessionState.coordinator.promotePreviewTab()
+                                sessionState.coordinator.openTableTab(table.name, isView: isView)
+                            }
+                        },
                         pendingTruncates: sessionPendingTruncatesBinding,
                         pendingDeletes: sessionPendingDeletesBinding,
                         tableOperationOptions: sessionTableOperationOptionsBinding,

TablePro/Core/Services/Infrastructure/SessionStateFactory.swift

@@ -50,11 +50,19 @@ enum SessionStateFactory {
             switch payload.tabType {
             case .table:
                 if let tableName = payload.tableName {
-                    tabMgr.addTableTab(
-                        tableName: tableName,
-                        databaseType: connection.type,
-                        databaseName: payload.databaseName ?? connection.database
-                    )
+                    if payload.isPreview {
+                        tabMgr.addPreviewTableTab(
+                            tableName: tableName,
+                            databaseType: connection.type,
+                            databaseName: payload.databaseName ?? connection.database
+                        )
+                    } else {
+                        tabMgr.addTableTab(
+                            tableName: tableName,
+                            databaseType: connection.type,
+                            databaseName: payload.databaseName ?? connection.database
+                        )
+                    }
                     if let index = tabMgr.selectedTabIndex {
                         tabMgr.tabs[index].isView = payload.isView
                         tabMgr.tabs[index].isEditable = !payload.isView

TablePro/Core/Services/Infrastructure/TabPersistenceCoordinator.swift

@@ -37,12 +37,18 @@ internal final class TabPersistenceCoordinator {
     /// Save tab state to disk. Called explicitly at named business events
     /// (tab switch, window close, quit, etc.).
     internal func saveNow(tabs: [QueryTab], selectedTabId: UUID?) {
-        let persisted = tabs.map { convertToPersistedTab($0) }
+        let nonPreviewTabs = tabs.filter { !$0.isPreview }
+        guard !nonPreviewTabs.isEmpty else {
+            clearSavedState()
+            return
+        }
+        let persisted = nonPreviewTabs.map { convertToPersistedTab($0) }
         let connId = connectionId
-        let selectedId = selectedTabId
+        let normalizedSelectedId = nonPreviewTabs.contains(where: { $0.id == selectedTabId })
+            ? selectedTabId : nonPreviewTabs.first?.id
 
         Task {
-            await TabDiskActor.shared.save(connectionId: connId, tabs: persisted, selectedTabId: selectedId)
+            await TabDiskActor.shared.save(connectionId: connId, tabs: persisted, selectedTabId: normalizedSelectedId)
         }
     }
 
@@ -60,8 +66,15 @@ internal final class TabPersistenceCoordinator {
     /// Synchronous save for `applicationWillTerminate` where no run loop
     /// remains to service async Tasks. Bypasses the actor and writes directly.
     internal func saveNowSync(tabs: [QueryTab], selectedTabId: UUID?) {
-        let persisted = tabs.map { convertToPersistedTab($0) }
-        TabDiskActor.saveSync(connectionId: connectionId, tabs: persisted, selectedTabId: selectedTabId)
+        let nonPreviewTabs = tabs.filter { !$0.isPreview }
+        guard !nonPreviewTabs.isEmpty else {
+            TabDiskActor.saveSync(connectionId: connectionId, tabs: [], selectedTabId: nil)
+            return
+        }
+        let persisted = nonPreviewTabs.map { convertToPersistedTab($0) }
+        let normalizedSelectedId = nonPreviewTabs.contains(where: { $0.id == selectedTabId })
+            ? selectedTabId : nonPreviewTabs.first?.id
+        TabDiskActor.saveSync(connectionId: connectionId, tabs: persisted, selectedTabId: normalizedSelectedId)
     }
 
     // MARK: - Clear

TablePro/Core/Services/Infrastructure/WindowLifecycleMonitor.swift

@@ -18,6 +18,7 @@ internal final class WindowLifecycleMonitor {
         let connectionId: UUID
         let window: NSWindow
         var observer: NSObjectProtocol?
+        var isPreview: Bool = false
     }
 
     private var entries: [UUID: Entry] = [:]
@@ -36,7 +37,7 @@ internal final class WindowLifecycleMonitor {
     // MARK: - Registration
 
     /// Register a window and start observing its willCloseNotification.
-    internal func register(window: NSWindow, connectionId: UUID, windowId: UUID) {
+    internal func register(window: NSWindow, connectionId: UUID, windowId: UUID, isPreview: Bool = false) {
         // Remove any existing entry for this windowId to avoid duplicate observers
         if let existing = entries[windowId] {
             if let observer = existing.observer {
@@ -58,7 +59,8 @@ internal final class WindowLifecycleMonitor {
         entries[windowId] = Entry(
             connectionId: connectionId,
             window: window,
-            observer: observer
+            observer: observer,
+            isPreview: isPreview
         )
     }
 
@@ -115,6 +117,22 @@ internal final class WindowLifecycleMonitor {
         entries[windowId] != nil
     }
 
+    /// Find the first preview window for a connection.
+    internal func previewWindow(for connectionId: UUID) -> (windowId: UUID, window: NSWindow)? {
+        entries.first { $0.value.connectionId == connectionId && $0.value.isPreview }
+            .map { ($0.key, $0.value.window) }
+    }
+
+    /// Look up the NSWindow for a given windowId.
+    internal func window(for windowId: UUID) -> NSWindow? {
+        entries[windowId]?.window
+    }
+
+    /// Update the preview flag for a registered window.
+    internal func setPreview(_ isPreview: Bool, for windowId: UUID) {
+        entries[windowId]?.isPreview = isPreview
+    }
+
     // MARK: - Private
 
     private func handleWindowClose(_ closedWindow: NSWindow) {

TablePro/Models/Query/EditorTabPayload.swift

@@ -29,6 +29,8 @@ internal struct EditorTabPayload: Codable, Hashable {
     internal let showStructure: Bool
     /// Whether to skip automatic query execution (used for restored tabs that should lazy-load)
     internal let skipAutoExecute: Bool
+    /// Whether this tab is a preview (temporary) tab
+    internal let isPreview: Bool
 
     internal init(
         id: UUID = UUID(),
@@ -39,7 +41,8 @@ internal struct EditorTabPayload: Codable, Hashable {
         initialQuery: String? = nil,
         isView: Bool = false,
         showStructure: Bool = false,
-        skipAutoExecute: Bool = false
+        skipAutoExecute: Bool = false,
+        isPreview: Bool = false
     ) {
         self.id = id
         self.connectionId = connectionId
@@ -50,6 +53,7 @@ internal struct EditorTabPayload: Codable, Hashable {
         self.isView = isView
         self.showStructure = showStructure
         self.skipAutoExecute = skipAutoExecute
+        self.isPreview = isPreview
     }
 
     internal init(from decoder: Decoder) throws {
@@ -63,6 +67,7 @@ internal struct EditorTabPayload: Codable, Hashable {
         isView = try container.decodeIfPresent(Bool.self, forKey: .isView) ?? false
         showStructure = try container.decodeIfPresent(Bool.self, forKey: .showStructure) ?? false
         skipAutoExecute = try container.decodeIfPresent(Bool.self, forKey: .skipAutoExecute) ?? false
+        isPreview = try container.decodeIfPresent(Bool.self, forKey: .isPreview) ?? false
     }
 
     /// Whether this payload is a "connection-only" payload — just a connectionId
@@ -83,5 +88,6 @@ internal struct EditorTabPayload: Codable, Hashable {
         self.isView = tab.isView
         self.showStructure = tab.showStructure
         self.skipAutoExecute = skipAutoExecute
+        self.isPreview = false
     }
 }

TablePro/Models/Query/QueryTab.swift

@@ -353,6 +353,9 @@ struct QueryTab: Identifiable, Equatable {
     // Per-tab column layout (widths/order persist across reloads within tab session)
     var columnLayout: ColumnLayoutState
 
+    // Whether this tab is a preview (temporary) tab that gets replaced on next navigation
+    var isPreview: Bool
+
     // Version counter incremented when resultRows changes (used for sort caching)
     var resultVersion: Int
 
@@ -389,6 +392,7 @@ struct QueryTab: Identifiable, Equatable {
         self.pagination = PaginationState()
         self.filterState = TabFilterState()
         self.columnLayout = ColumnLayoutState()
+        self.isPreview = false
         self.resultVersion = 0
         self.metadataVersion = 0
     }
@@ -420,6 +424,7 @@ struct QueryTab: Identifiable, Equatable {
         self.pagination = PaginationState()
         self.filterState = TabFilterState()
         self.columnLayout = ColumnLayoutState()
+        self.isPreview = false
         self.resultVersion = 0
         self.metadataVersion = 0
     }
@@ -484,6 +489,8 @@ struct QueryTab: Identifiable, Equatable {
             && lhs.isView == rhs.isView
             && lhs.tabType == rhs.tabType
             && lhs.rowsAffected == rhs.rowsAffected
+            && lhs.isPreview == rhs.isPreview
+            && lhs.hasUserInteraction == rhs.hasUserInteraction
     }
 }
 
@@ -550,13 +557,30 @@ final class QueryTabManager {
         selectedTabId = newTab.id
     }
 
+    func addPreviewTableTab(tableName: String, databaseType: DatabaseType = .mysql, databaseName: String = "") {
+        let pageSize = AppSettingsManager.shared.dataGrid.defaultPageSize
+        let query = QueryTab.buildBaseTableQuery(tableName: tableName, databaseType: databaseType)
+        var newTab = QueryTab(
+            title: tableName,
+            query: query,
+            tabType: .table,
+            tableName: tableName
+        )
+        newTab.pagination = PaginationState(pageSize: pageSize)
+        newTab.databaseName = databaseName
+        newTab.isPreview = true
+        tabs.append(newTab)
+        selectedTabId = newTab.id
+    }
+
     /// Replace the currently selected tab's content with a new table.
     /// - Returns: `true` if the replacement happened (caller should run the query),
     ///   `false` if there is no selected tab.
     @discardableResult
     func replaceTabContent(
         tableName: String, databaseType: DatabaseType = .mysql,
-        isView: Bool = false, databaseName: String = ""
+        isView: Bool = false, databaseName: String = "",
+        isPreview: Bool = false
     ) -> Bool {
         guard let selectedId = selectedTabId,
               let selectedIndex = tabs.firstIndex(where: { $0.id == selectedId })
@@ -603,6 +627,7 @@ final class QueryTabManager {
         tab.columnLayout = ColumnLayoutState()
         tab.pagination = PaginationState(pageSize: pageSize)
         tab.databaseName = databaseName
+        tab.isPreview = isPreview
         tabs[selectedIndex] = tab
         return true
     }

TablePro/Models/Settings/AppSettings.swift

@@ -482,5 +482,15 @@ struct HistorySettings: Codable, Equatable {
 
 /// Tab behavior settings
 struct TabSettings: Codable, Equatable {
+    var enablePreviewTabs: Bool = true
     static let `default` = TabSettings()
+
+    init(enablePreviewTabs: Bool = true) {
+        self.enablePreviewTabs = enablePreviewTabs
+    }
+
+    init(from decoder: Decoder) throws {
+        let container = try decoder.container(keyedBy: CodingKeys.self)
+        enablePreviewTabs = try container.decodeIfPresent(Bool.self, forKey: .enablePreviewTabs) ?? true
+    }
 }