优化 EPUB 翻页与后台分页刷新

Sources/RDReaderView/EPUBUI/ReaderController/RDEPUBReaderEnvironment.swift

@@ -1,5 +1,27 @@
 import UIKit
 
+enum RDEPUBTextPageLayoutMetrics {
+
+    static let pageNumberTrailingPadding: CGFloat = 4
+
+    static let pageNumberFooterPadding: CGFloat = 8
+
+    static let pageNumberReservedHeight: CGFloat = ceil(UIFont.systemFont(ofSize: 13).lineHeight) + pageNumberFooterPadding
+
+    static func contentInsets(
+        configuration: RDEPUBReaderConfiguration,
+        safeAreaInsets: UIEdgeInsets
+    ) -> UIEdgeInsets {
+        let configInsets = configuration.reflowableContentInsets
+        return UIEdgeInsets(
+            top: max(configInsets.top, safeAreaInsets.top),
+            left: max(configInsets.left, safeAreaInsets.left),
+            bottom: max(configInsets.bottom, safeAreaInsets.bottom) + pageNumberReservedHeight,
+            right: max(configInsets.right, safeAreaInsets.right)
+        )
+    }
+}
+
 final class RDEPUBReaderEnvironment {
 
     weak var controller: RDEPUBReaderController?
@@ -46,11 +68,14 @@ final class RDEPUBReaderEnvironment {
         configuration: RDEPUBReaderConfiguration,
         pageSize: CGSize
     ) -> RDEPUBTextLayoutConfig {
-        let layoutContext = currentLayoutContext(configuration: configuration)
+        let safeAreaInsets = controller?.view.safeAreaInsets ?? .zero
         return RDEPUBTextLayoutConfig(
             frameWidth: max(pageSize.width, 1),
             frameHeight: max(pageSize.height, 1),
-            edgeInsets: layoutContext.safeReflowableContentInsets,
+            edgeInsets: RDEPUBTextPageLayoutMetrics.contentInsets(
+                configuration: configuration,
+                safeAreaInsets: safeAreaInsets
+            ),
             numberOfColumns: configuration.numberOfColumns,
             columnGap: configuration.columnGap,
             avoidOrphans: false,