From b5d73ff2db2cccb7915bbc1c235aec12d8af8f67 Mon Sep 17 00:00:00 2001
From: zhangjiarui <zhangjiarui@uniontech.com>
Date: Mon, 21 Sep 2026 22:05:50 +0800
Subject: [PATCH] fix(reader): fix scrollbar invisible in dark mode by forcing
 light scrollbar palette
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1. 主题更新时强制两个滚动条的 QPalette::Base 为浅色，使滑块恒为深色;
2. 构造函数中连接 themeTypeChanged 并立即应用，覆盖深色模式下的初始状态;
3. 不改变视口/护眼模式背景逻辑，避免与 EyeProtectionManager 冲突;

=====================================

1. forced QPalette::Base of both scrollbars to a light color on theme update so the handle is always drawn dark;
2. connected themeTypeChanged and applied it immediately in the constructor to cover the initial dark-mode state;
3. left the viewport/eye-protection background logic untouched to avoid conflicting with EyeProtectionManager;

Log: 修复深色模式下文档查看器滚动条透明不可见的问题，放大文档后滚动条清晰可辨

PMS: BUG-374553
---
 reader/browser/SheetBrowser.cpp | 21 ++++++++++++++++++++-
 reader/browser/SheetBrowser.h   |  6 ++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/reader/browser/SheetBrowser.cpp b/reader/browser/SheetBrowser.cpp
index 8a7703425..9a30f1550 100644
--- a/reader/browser/SheetBrowser.cpp
+++ b/reader/browser/SheetBrowser.cpp
@@ -118,7 +118,11 @@ SheetBrowser::SheetBrowser(DocSheet *parent) : DGraphicsView(parent), m_sheet(pa
     QPalette pal = viewport()->palette();
     pal.setColor(viewport()->backgroundRole(), EyeProtectionManager::instance()->viewportBackgroundColor());
     viewport()->setPalette(pal);
-    
+
+    // 主题切换时同步滚动条调色板，保证深色模式下滑块可见
+    connect(DGuiApplicationHelper::instance(), &DGuiApplicationHelper::themeTypeChanged, this, &SheetBrowser::onUpdateTheme);
+    onUpdateTheme();
+
     qCDebug(appLog) << "SheetBrowser constructor completed";
 }
 
@@ -2474,3 +2478,18 @@ void SheetBrowser::restoreScrollPosition(float position)
     vBar->setValue(value);
     qCDebug(appLog) << "restoreScrollPosition set value=" << value << "-> after val=" << vBar->value();
 }
+
+void SheetBrowser::onUpdateTheme()
+{
+    // 文档页面与视口背景恒为浅色，而 DTK ChameleonStyle 依据滚动条 palette(Base)
+    // 的明暗决定滑块颜色：深色模式下 Base 为深色会绘制白色半透明滑块，在浅色
+    // 背景上不可见。此处强制 Base 为浅色，使滑块始终为深色，保证滚动条清晰可见。
+    const QPalette appPalette = DGuiApplicationHelper::instance()->applicationPalette();
+    auto syncScrollBarPalette = [&appPalette](QScrollBar *bar) {
+        QPalette barPalette = appPalette;
+        barPalette.setColor(QPalette::Base, Qt::white);
+        bar->setPalette(barPalette);
+    };
+    syncScrollBarPalette(verticalScrollBar());
+    syncScrollBarPalette(horizontalScrollBar());
+}
diff --git a/reader/browser/SheetBrowser.h b/reader/browser/SheetBrowser.h
index f8de05115..f1ffe99dc 100644
--- a/reader/browser/SheetBrowser.h
+++ b/reader/browser/SheetBrowser.h
@@ -579,6 +579,12 @@ private slots:
      */
     void onRemoveIconAnnotSelect();
 
+    /**
+     * @brief onUpdateTheme
+     * 主题变化时更新滚动条调色板，确保深色模式下滚动条颜色正确
+     */
+    void onUpdateTheme();
+
 private:
     /**
      * @brief calcIconAnnotRect