From c173f5b523d6c0491d73f714183c3af0916a1155 Mon Sep 17 00:00:00 2001
From: John Factotum <50942278+johnfactotum@users.noreply.github.com>
Date: Sat, 1 Apr 2023 23:33:10 +0800
Subject: [PATCH] Paginator: allow injecting CSS *before* the book's stylesheet

Before this commit: `setStyle()` takes a single string argument, which
is the stylesheet it will append to head.

After this commit: it optionally accepts two stylesheet strings in an
array, the first of which will be prepended, allowing the reading system
to set default styles that can be overridden by the book.
---
 paginator.js | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/paginator.js b/paginator.js
index 14860a1..143dde9 100644
--- a/paginator.js
+++ b/paginator.js
@@ -623,9 +623,11 @@ export class Paginator {
             const view = this.#createView()
             const afterLoad = doc => {
                 if (doc.head) {
+                    const $styleBefore = doc.createElement('style')
+                    doc.head.prepend($styleBefore)
                     const $style = doc.createElement('style')
                     doc.head.append($style)
-                    this.#styleMap.set(doc, $style)
+                    this.#styleMap.set(doc, [$styleBefore, $style])
                 }
                 onLoad?.(doc, index)
             }
@@ -735,9 +737,15 @@ export class Paginator {
             doc: this.#view.document,
         }
     }
-    setStyle(style) {
-        const $style = this.#styleMap.get(this.#view?.document)
-        if ($style) $style.textContent = style
+    setStyle(styles) {
+        const $$styles = this.#styleMap.get(this.#view?.document)
+        if (!$$styles) return
+        const [$beforeStyle, $style] = $$styles
+        if (Array.isArray(styles)) {
+            const [beforeStyle, style] = styles
+            $beforeStyle.textContent = beforeStyle
+            $style.textContent = style
+        } else $style.textContent = styles
     }
     deselect() {
         const sel = this.#view.document.defaultView.getSelection()