WIP: add Quick Look preview groundwork

sources/clipbored/services/ClipboardCacheService.swift

@@ -182,6 +182,23 @@ final class ClipboardCacheService {
     }
   }
 
+  func temporaryPreviewURL(for item: ClipboardItem) -> URL? {
+    switch item.kind {
+    case .file:
+      let urls = FilePayload.urls(from: item.payload)
+      return urls.first { fileManager.fileExists(atPath: $0.path) }
+    case .text, .unknown:
+      let text = item.payload.clipboardTrimmed.isEmpty ? item.displayText : item.payload
+      guard !text.clipboardTrimmed.isEmpty else { return nil }
+      return writeTemporaryCopy(data: Data(text.utf8), id: item.id, fileExtension: "txt")
+    case .url:
+      guard let data = webLocationData(for: item.payload) else { return nil }
+      return writeTemporaryCopy(data: data, id: item.id, fileExtension: "webloc")
+    case .image, .pdf, .audio, .richText:
+      return temporaryReadableURL(for: item)
+    }
+  }
+
   func encryptCachedReferencesIfNeeded(for items: [ClipboardItem]) {
     queue.async { [weak self] in
       guard let self else { return }
@@ -320,6 +337,16 @@ final class ClipboardCacheService {
     }
   }
 
+  private func webLocationData(for value: String) -> Data? {
+    let trimmed = value.clipboardTrimmed
+    guard !trimmed.isEmpty else { return nil }
+    return try? PropertyListSerialization.data(
+      fromPropertyList: ["URL": trimmed],
+      format: .xml,
+      options: 0
+    )
+  }
+
   private func removeTemporaryPreviewFiles() {
     guard fileManager.fileExists(atPath: temporaryPreviewDirectory.path) else {
       return

sources/clipbored/views/ClipboardPanelController.swift

@@ -1,4 +1,5 @@
 import AppKit
+import QuickLook
 
 struct ClipboardPanelAnimationProfile {
   let showDuration: TimeInterval
@@ -15,10 +16,11 @@ struct ClipboardPanelReflowPlan {
 enum ClipboardPanelShortcutAction: Equatable {
   case copy
   case open
+  case preview
   case reveal
 }
 
-final class ClipboardPanelController: NSObject, NSWindowDelegate {
+final class ClipboardPanelController: NSObject, NSWindowDelegate, QLPreviewPanelDataSource, QLPreviewPanelDelegate {
   private enum Animation {
     static let showDuration: TimeInterval = 0.16
     static let hideDuration: TimeInterval = 0.12
@@ -44,6 +46,7 @@ final class ClipboardPanelController: NSObject, NSWindowDelegate {
   private let preferredScreenProvider: () -> NSScreen?
   private let openSettings: () -> Void
   private var isAnimating = false
+  private var quickLookURL: URL?
   private var screenParametersObserver: NSObjectProtocol?
   private static let collectionShortcuts: [UInt16: ClipboardSortMode] = [
     18: .mostRecent,
@@ -82,7 +85,8 @@ final class ClipboardPanelController: NSObject, NSWindowDelegate {
     panelView = ClipboardPanelView(
       viewModel: viewModel,
       onClose: { [weak self] in self?.hide() },
-      onSettings: { [weak self] in self?.openSettings() }
+      onSettings: { [weak self] in self?.openSettings() },
+      onPreview: { [weak self] in self?.previewSelected() }
     )
 
     let contentSize = NSSize(width: 1200, height: 420)
@@ -333,6 +337,9 @@ final class ClipboardPanelController: NSObject, NSWindowDelegate {
       case 53:
         self.hide()
         return nil
+      case 49:
+        self.previewSelected()
+        return nil
       case 36:
         self.viewModel.pasteSelected()
         return nil
@@ -360,11 +367,26 @@ final class ClipboardPanelController: NSObject, NSWindowDelegate {
       viewModel.copySelected()
     case .open:
       viewModel.openSelected()
+    case .preview:
+      previewSelected()
     case .reveal:
       viewModel.revealSelected()
     }
   }
 
+  private func previewSelected() {
+    guard let url = viewModel.previewURLForSelected() else { return }
+    quickLookURL = url
+    guard let previewPanel = QLPreviewPanel.shared() else {
+      NSWorkspace.shared.open(url)
+      return
+    }
+    previewPanel.dataSource = self
+    previewPanel.delegate = self
+    previewPanel.currentPreviewItemIndex = 0
+    previewPanel.makeKeyAndOrderFront(nil)
+  }
+
   private func shouldHandlePanelKeyEvent(_ event: NSEvent) -> Bool {
     shouldHandlePanelKeyEvent(event, allowSearchFieldEditing: false)
   }
@@ -399,6 +421,8 @@ final class ClipboardPanelController: NSObject, NSWindowDelegate {
       return .copy
     case 31:
       return .open
+    case 16:
+      return .preview
     case 15:
       return .reveal
     default:
@@ -406,6 +430,14 @@ final class ClipboardPanelController: NSObject, NSWindowDelegate {
     }
   }
 
+  func numberOfPreviewItems(in panel: QLPreviewPanel!) -> Int {
+    quickLookURL == nil ? 0 : 1
+  }
+
+  func previewPanel(_ panel: QLPreviewPanel!, previewItemAt index: Int) -> QLPreviewItem! {
+    quickLookURL as NSURL?
+  }
+
   #if DEBUG
   var debugPanelFrame: NSRect {
     panel.frame

sources/clipbored/views/ClipboardPanelViewModel.swift

@@ -168,6 +168,15 @@ final class ClipboardPanelViewModel {
     return pasteService.pasteboardWriters(for: visibleItems[index])
   }
 
+  func previewURLForSelected() -> URL? {
+    guard let item = selectedItem else { return nil }
+    return previewURL(for: item)
+  }
+
+  internal func previewURL(for item: ClipboardItem) -> URL? {
+    cacheService.temporaryPreviewURL(for: item)
+  }
+
   func openSelected() {
     guard let item = selectedItem else { return }
     switch item.kind {