Implement themed rendering for ListView and Header with hover effects

- ThemeRenderer: Added subclassing and themed rendering for WC_LISTVIEW and WC_HEADER.
- ThemeRenderer: Implemented dark mode header painting with manual GDI calls (background, text, separators, sort arrows).
- ThemeRenderer: Added hover support for header items and list items using primary_bg.
- ThemeRenderer: Configured non-blocking NM_CUSTOMDRAW handling to allow component-specific drawing.
- FileList: Maintained specific logic for underlining open files and parent icons, updated for dialog compatibility.
- Consistent theme and dark scrollbar application for TreeView and ListView.

Co-authored-by: funap <31555185+funap@users.noreply.github.com>

Author: google-labs-jules[bot]

src/Explorer/Explorer.cpp

@@ -303,7 +303,6 @@ void UpdateThemeColor()
         .primary            = editorColors.text,
         .primary_bg         = editorColors.hotBackground,
         .primary_border     = editorColors.hotEdge,
-        .hover_bg           = editorColors.hotBackground,
     };
     auto isDarkMode = IsDarkColor(colors.body_bg);
     ThemeRenderer::Instance().SetTheme(isDarkMode, colors);

src/Explorer/FileList.h

@@ -46,7 +46,6 @@ static const WORD DotPattern[] =
 };
 
 #include "FileSystemService.h"
-#include "ThemeRenderer.h"
 
 
 class FileList : public Window, public CIDropTarget

src/Explorer/ThemeRenderer.cpp

@@ -115,7 +115,6 @@ void ThemeRenderer::SetTheme(BOOL isDarkMode, const ThemeColors& colors)
     m_brushes.primary.CreateSolidBrush(colors.primary);
     m_brushes.primary_bg.CreateSolidBrush(colors.primary_bg);
     m_brushes.primary_border.CreateSolidBrush(colors.primary_border);
-    m_brushes.hover_bg.CreateSolidBrush(colors.hover_bg);
 
     for (const auto& hwnd : m_windows) {
         ApplyTheme(hwnd);
@@ -244,7 +243,7 @@ LRESULT ThemeRenderer::WindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lP
                         }
                         else if (lpCD->nmcd.uItemState & CDIS_HOT) {
                             lpCD->clrText = m_colors.primary;
-                            lpCD->clrTextBk = m_colors.hover_bg;
+                            lpCD->clrTextBk = m_colors.primary_bg;
                         }
 
                         LRESULT res = ::DefSubclassProc(hWnd, uMsg, wParam, lParam);
@@ -355,7 +354,7 @@ LRESULT ThemeRenderer::HeaderProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lP
             Header_GetItemRect(hWnd, i, &rcItem);
 
             if (i == m_hotHeaderItem && m_hHeaderTracked == hWnd) {
-                FillRect(hdc, &rcItem, m_brushes.hover_bg);
+                FillRect(hdc, &rcItem, m_brushes.primary_bg);
             }
 
             // Draw text

src/Explorer/ThemeRenderer.h

@@ -42,7 +42,6 @@ struct ThemeColors
     COLORREF primary        = ::GetSysColor(COLOR_HIGHLIGHTTEXT);
     COLORREF primary_bg     = ::GetSysColor(COLOR_HIGHLIGHT);
     COLORREF primary_border = ::GetSysColor(COLOR_ACTIVEBORDER);
-    COLORREF hover_bg       = ::GetSysColor(COLOR_HOTLIGHT);
 };
 
 
@@ -56,7 +55,6 @@ struct Brushes
     Brush primary;        // for primary/highlighted text
     Brush primary_bg;     // for primary/highlighted background
     Brush primary_border; // for primary element borders
-    Brush hover_bg;       // for hover background
 };