diff --git a/Packages/vChewing_CandidateWindow/README.md b/Packages/vChewing_CandidateWindow/README.md
index 31da3503..f4370531 100644
--- a/Packages/vChewing_CandidateWindow/README.md
+++ b/Packages/vChewing_CandidateWindow/README.md
@@ -9,7 +9,7 @@ TDK 選字窗以純 SwiftUI 構築，用以取代此前自上游繼承來的 Vol
 然而，TDK 選字窗目前有下述侷限：
 
 - 因 SwiftUI 自身特性所導致的嚴重的效能問題。基本上來講，如果您經常使用全字庫模式的話，請在偏好設定內啟用效能更高的 IMK 選字窗。
-- 同樣出於上述原因，為了讓田所選字窗至少處於可在生產力環境下正常使用的狀態，就犧牲了捲動檢視的功能。也就是說，每次只顯示六行，但顯示內容則隨著使用者的游標操作而更新。
+- 同樣出於上述原因，為了讓田所選字窗至少處於可在生產力環境下正常使用的狀態，就犧牲了捲動檢視的功能。也就是說，每次只顯示三行，但顯示內容則隨著使用者的游標操作而更新。
 - TDK 選字窗目前僅完成了橫版矩陣陳列模式的實作，且尚未引入對縱排選字窗陳列佈局的支援。
 
 因為這些問題恐怕需要很久才能全部解決，所以威注音會在這段時間內推薦使用者們優先使用 IMK 選字窗。
diff --git a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CandidatePool.swift b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CandidatePool.swift
index 2c090641..31d67658 100644
--- a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CandidatePool.swift
+++ b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CandidatePool.swift
@@ -10,21 +10,24 @@ import Cocoa
 import Shared
 
 /// 候選字窗會用到的資料池單位。
-public struct CandidatePool {
+public class CandidatePool {
   public var currentRowNumber = 0
+  public var maximumLinesPerPage = 3
   public private(set) var selectionKeys: String
   public private(set) var highlightedIndex: Int = 0
   public private(set) var maxColumnCapacity: Int = 6
   public private(set) var candidateDataAll: [CandidateCellData] = []
   public private(set) var candidateRows: [[CandidateCellData]] = []
-  public var maxWindowHeight: Double { ceil(maxWindowWidth * 0.4) }
   public var isVerticalLayout: Bool { maxColumnCapacity == 1 }
   public var maxColumnWidth: Int { Int(Double(maxColumnCapacity + 3) * 2) * Int(ceil(CandidateCellData.unifiedSize)) }
+  public var maxWindowHeight: Double { ceil(maxWindowWidth * 0.4 / 2) }
   public var maxWindowWidth: Double {
     ceil(Double(maxColumnCapacity + 3) * 2.7 * ceil(CandidateCellData.unifiedSize) * 1.2)
   }
 
-  public var rangeForCurrentPage: Range<Int> { currentRowNumber..<min(candidateRows.count, currentRowNumber + 6) }
+  public var rangeForCurrentPage: Range<Int> {
+    currentRowNumber..<min(candidateRows.count, currentRowNumber + maximumLinesPerPage)
+  }
 
   public enum VerticalDirection {
     case up
@@ -56,7 +59,7 @@ public struct CandidatePool {
     candidateRows.append(currentColumn)
   }
 
-  public mutating func selectNewNeighborRow(direction: VerticalDirection) {
+  public func selectNewNeighborRow(direction: VerticalDirection) {
     let currentSubIndex = candidateDataAll[highlightedIndex].subIndex
     var result = currentSubIndex
     switch direction {
@@ -94,7 +97,7 @@ public struct CandidatePool {
     }
   }
 
-  public mutating func highlight(at indexSpecified: Int) {
+  public func highlight(at indexSpecified: Int) {
     var indexSpecified = indexSpecified
     highlightedIndex = indexSpecified
     if !(0..<candidateDataAll.count).contains(highlightedIndex) {
diff --git a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CtlCandidateTDK.swift b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CtlCandidateTDK.swift
index c434d82d..f611393a 100644
--- a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CtlCandidateTDK.swift
+++ b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CtlCandidateTDK.swift
@@ -65,7 +65,7 @@ public class CtlCandidateTDK: CtlCandidate {
   }
 
   @discardableResult override public func showNextPage() -> Bool {
-    for _ in 0..<6 {
+    for _ in 0..<thePool.maximumLinesPerPage {
       thePool.selectNewNeighborRow(direction: .down)
     }
     updateDisplay()
@@ -73,7 +73,7 @@ public class CtlCandidateTDK: CtlCandidate {
   }
 
   @discardableResult override public func showPreviousPage() -> Bool {
-    for _ in 0..<6 {
+    for _ in 0..<thePool.maximumLinesPerPage {
       thePool.selectNewNeighborRow(direction: .up)
     }
     updateDisplay()
diff --git a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/VwrCandidateTDK.swift b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/VwrCandidateTDK.swift
index 45a32632..e5bc40d9 100644
--- a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/VwrCandidateTDK.swift
+++ b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/VwrCandidateTDK.swift
@@ -21,7 +21,7 @@ struct CandidatePoolViewUI_Previews: PreviewProvider {
     "吹", "大", "地", "草", "枝", "擺",
   ]
   static var thePool: CandidatePool {
-    var result = CandidatePool(candidates: testCandidates, columnCapacity: 6)
+    let result = CandidatePool(candidates: testCandidates, columnCapacity: 6)
     // 下一行待解決：無論這裡怎麼指定高亮選中項是哪一筆，其所在行都得被卷動到使用者眼前。
     result.highlight(at: 14)
     return result