feat: navigate with up/down arrow keys (closes #270)

src/logic/Window.swift

@@ -14,6 +14,7 @@ class Window {
     var axUiElement: AXUIElement
     var application: Application
     var axObserver: AXObserver?
+    var row: Int?
 
     static let notifications = [
         kAXUIElementDestroyedNotification,

src/ui/App.swift

@@ -134,11 +134,15 @@ class App: NSApplication, NSApplicationDelegate {
     func showUi() {
         appIsBeingUsed = true
         appIsBeingUsed = true
-        DispatchQueue.main.async { () -> () in self.showUiOrCycleSelection(0) }
+        DispatchQueue.main.async { () -> () in self.showUiOrCycleSelection(.neutral) }
     }
 
-    func cycleSelection(_ step: Int) {
-        Windows.cycleFocusedWindowIndex(step)
+    func cycleSelection(_ direction: Direction) {
+        if direction == .left || direction == .right || direction == .neutral {
+            Windows.cycleFocusedWindowIndex(direction.step())
+        } else {
+            thumbnailsPanel.thumbnailsView.navigateUpOrDown(direction)
+        }
     }
 
     func focusSelectedWindow(_ window: Window?) {
@@ -183,8 +187,8 @@ class App: NSApplication, NSApplicationDelegate {
         }
     }
 
-    func showUiOrCycleSelection(_ step: Int) {
-        debugPrint("showUiOrCycleSelection", step)
+    func showUiOrCycleSelection(_ direction: Direction) {
+        debugPrint("showUiOrCycleSelection", direction)
         if isFirstSummon {
             debugPrint("showUiOrCycleSelection: isFirstSummon")
             isFirstSummon = false
@@ -197,12 +201,12 @@ class App: NSApplication, NSApplicationDelegate {
             Windows.refreshWhichWindowsToShowTheUser(screen)
             if Windows.list.first(where: { $0.shouldShowTheUser }) == nil { hideUi(); return }
             Windows.updateFocusedWindowIndex(0)
-            Windows.cycleFocusedWindowIndex(step)
+            Windows.cycleFocusedWindowIndex(direction.step())
             DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + Preferences.windowDisplayDelay) { () -> () in
                 self.rebuildUi()
             }
         } else {
-            cycleSelection(step)
+            cycleSelection(direction)
         }
     }
 

src/ui/main-window/ThumbnailsView.swift

@@ -3,6 +3,7 @@ import Cocoa
 class ThumbnailsView: NSVisualEffectView {
     let scrollView = ScrollView()
     static var recycledViews = [ThumbnailView]()
+    var rows = [[ThumbnailView]]()
 
     convenience init() {
         self.init(frame: .zero)
@@ -15,6 +16,26 @@ class ThumbnailsView: NSVisualEffectView {
         (1...100).forEach { _ in ThumbnailsView.recycledViews.append(ThumbnailView()) }
     }
 
+    func nextRow(_ direction: Direction) -> [ThumbnailView] {
+        let step = direction == .down ? 1 : -1
+        let indexAfterStep = (Windows.focusedWindow()!.row! + step) % rows.count
+        let targetRowIndex = indexAfterStep < 0 ? rows.count + indexAfterStep : indexAfterStep
+        return rows[targetRowIndex]
+    }
+
+    func navigateUpOrDown(_ direction: Direction) {
+        let focusedViewFrame = ThumbnailsView.recycledViews[Windows.focusedWindowIndex].frame
+        let originCenter = NSMidX(focusedViewFrame)
+        let targetRow = nextRow(direction)
+        let leftSide = originCenter < NSMidX(frame)
+        let iterable = leftSide ? targetRow : targetRow.reversed()
+        let targetView = iterable.first(where: {
+            leftSide ? NSMaxX($0.frame) > originCenter : NSMinX($0.frame) < originCenter
+        }) ?? iterable.last!
+        let targetIndex = ThumbnailsView.recycledViews.firstIndex(of: targetView)!
+        Windows.updateFocusedWindowIndex(targetIndex)
+    }
+
     func updateItems(_ screen: NSScreen) {
         let widthMax = ThumbnailsPanel.widthMax(screen).rounded()
         let heightMax = ThumbnailsPanel.heightMax(screen).rounded()
@@ -24,6 +45,8 @@ class ThumbnailsView: NSVisualEffectView {
         var maxX = CGFloat(0)
         var maxY = height
         var newViews = [ThumbnailView]()
+        rows.removeAll()
+        rows.append([ThumbnailView]())
         for (index, window) in Windows.list.enumerated() {
             guard App.app.appIsBeingUsed else { return }
             guard window.shouldShowTheUser else { continue }
@@ -37,12 +60,15 @@ class ThumbnailsView: NSVisualEffectView {
                 currentX = CGFloat(0)
                 currentY = (currentY + Preferences.interCellPadding + height).rounded(.down)
                 maxY = max(currentY + height, maxY)
+                rows.append([ThumbnailView]())
             } else {
                 maxX = max(currentX + width, maxX)
             }
             view.frame.origin = CGPoint(x: currentX, y: currentY)
             currentX = (currentX + Preferences.interCellPadding + width).rounded(.down)
             newViews.append(view)
+            rows[rows.count - 1].append(view)
+            window.row = rows.count - 1
         }
         scrollView.documentView!.subviews = newViews
         frame.size = NSSize(width: min(maxX, widthMax) + Preferences.windowPadding * 2, height: min(maxY, heightMax) + Preferences.windowPadding * 2)
@@ -126,3 +152,20 @@ class ScrollView: NSScrollView {
 class FlippedView: NSView {
     override var isFlipped: Bool { true }
 }
+
+enum Direction {
+    case neutral
+    case left
+    case right
+    case up
+    case down
+
+    func step() -> Int {
+        if self == .left {
+            return -1
+        } else if self == .right {
+            return 1
+        }
+        return 0
+    }
+}

src/ui/preferences-window/tabs/GeneralTab.swift

@@ -11,10 +11,12 @@ class GeneralTab: NSViewController, PreferencePane {
     static var shortcutsDependentOnHoldShortcut = [NSControl]()
     static var shortcutsActionsBlocks = [
         "holdShortcut": { App.app.focusTarget() },
-        "nextWindowShortcut": { App.app.showUiOrCycleSelection(1) },
-        "previousWindowShortcut": { App.app.showUiOrCycleSelection(-1) },
-        "→": { App.app.cycleSelection(1) },
-        "←": { App.app.cycleSelection(-1) },
+        "nextWindowShortcut": { App.app.showUiOrCycleSelection(.right) },
+        "previousWindowShortcut": { App.app.showUiOrCycleSelection(.left) },
+        "→": { App.app.cycleSelection(.right) },
+        "←": { App.app.cycleSelection(.left) },
+        "↑": { App.app.cycleSelection(.up) },
+        "↓": { App.app.cycleSelection(.down) },
         "cancelShortcut": { App.app.hideUi() },
         "closeWindowShortcut": { App.app.closeSelectedWindow() },
         "minDeminWindowShortcut": { App.app.minDeminSelectedWindow() },
@@ -86,7 +88,7 @@ class GeneralTab: NSViewController, PreferencePane {
                     App.app.isFirstSummon = true
                 }
                 let fn = shortcutsActionsBlocks[controlId]!
-                let isShortcutAffectingTheUi = ["previousWindowShortcut", "nextWindowShortcut", "←", "→", "holdShortcut"].contains(controlId)
+                let isShortcutAffectingTheUi = ["previousWindowShortcut", "nextWindowShortcut", "←", "→", "↑", "↓", "holdShortcut"].contains(controlId)
                 if isShortcutAffectingTheUi || isShortcutClosingTheUi {
                     DispatchQueue.main.async { () -> () in fn() }
                 } else {
@@ -115,12 +117,11 @@ class GeneralTab: NSViewController, PreferencePane {
     }
 
     @objc static func arrowKeysEnabledCallback(_ sender: NSControl) {
+        let keys = ["←", "→", "↑", "↓"]
         if (sender as! NSButton).state == .on {
-            addShortcut(.down, Shortcut(keyEquivalent: Preferences.holdShortcut + "→")!, "→")
-            addShortcut(.down, Shortcut(keyEquivalent: Preferences.holdShortcut + "←")!, "←")
+            keys.forEach { addShortcut(.down, Shortcut(keyEquivalent: Preferences.holdShortcut + $0)!, $0) }
         } else {
-            removeShortcutIfExists("→", .down)
-            removeShortcutIfExists("←", .down)
+            keys.forEach { removeShortcutIfExists($0, .down) }
         }
     }