Restore custom fonts after theme changes

Explorer++/Explorer++/MainFontSetter.cpp

@@ -15,8 +15,7 @@ MainFontSetter::MainFontSetter(HWND hwnd, const Config *config,
 	m_config(config),
 	m_defaultFontAt96Dpi(defaultFontAt96Dpi)
 {
-	SubclassWindowForDpiChanges();
-	MaybeSubclassSpecificWindowClasses();
+	InstallWindowSubclass();
 	UpdateFont();
 
 	m_connections.push_back(
@@ -25,7 +24,7 @@ MainFontSetter::MainFontSetter(HWND hwnd, const Config *config,
 
 MainFontSetter::~MainFontSetter() = default;
 
-void MainFontSetter::SubclassWindowForDpiChanges()
+void MainFontSetter::InstallWindowSubclass()
 {
 	m_windowSubclasses.push_back(
 		std::make_unique<WindowSubclass>(m_hwnd, std::bind_front(&MainFontSetter::WndProc, this)));
@@ -38,66 +37,38 @@ LRESULT MainFontSetter::WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lPara
 	case WM_DPICHANGED_AFTERPARENT:
 		OnDpiChanged();
 		break;
-	}
-
-	return DefSubclassProc(hwnd, msg, wParam, lParam);
-}
 
-void MainFontSetter::OnDpiChanged()
-{
-	if (!m_config->mainFont.get() && !m_defaultFontAt96Dpi)
-	{
-		// In this situation, the control is using its default font, so there's no need to perform
-		// any manual updates.
-		return;
-	}
-
-	UpdateFont();
-}
-
-void MainFontSetter::MaybeSubclassSpecificWindowClasses()
-{
-	WCHAR className[256];
-	auto res = GetClassName(m_hwnd, className, static_cast<int>(std::size(className)));
-
-	if (res == 0)
-	{
-		DCHECK(false);
-		return;
-	}
-
-	if (lstrcmp(className, TOOLTIPS_CLASS) == 0)
-	{
-		m_windowSubclasses.push_back(std::make_unique<WindowSubclass>(m_hwnd,
-			std::bind_front(&MainFontSetter::TooltipWndProc, this)));
-	}
-}
-
-LRESULT MainFontSetter::TooltipWndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
-{
-	switch (msg)
-	{
 	case WM_THEMECHANGED:
 	{
 		auto res = DefSubclassProc(hwnd, msg, wParam, lParam);
 
-		// The tooltip control will internally reset its font when it receives a WM_THEMECHANGED
-		// message. Therefore, if a custom font is currently active within the application, that
-		// font will need to be restored. If a custom font isn't active, the control can use the
-		// default font it sets.
+		// Some controls, including toolbars and tooltips, reset their font when the theme is
+		// changed. Restore the active custom font after the control has processed the message.
 		if (m_font)
 		{
 			SendMessage(m_hwnd, WM_SETFONT, reinterpret_cast<WPARAM>(m_font.get()), true);
+			fontUpdatedSignal.m_signal();
 		}
 
 		return res;
 	}
-	break;
 	}
 
 	return DefSubclassProc(hwnd, msg, wParam, lParam);
 }
 
+void MainFontSetter::OnDpiChanged()
+{
+	if (!m_config->mainFont.get() && !m_defaultFontAt96Dpi)
+	{
+		// In this situation, the control is using its default font, so there's no need to perform
+		// any manual updates.
+		return;
+	}
+
+	UpdateFont();
+}
+
 void MainFontSetter::UpdateFont()
 {
 	// If a custom font isn't active, the default value (nullptr) will be passed into

Explorer++/Explorer++/MainFontSetter.h

@@ -25,11 +25,9 @@ class MainFontSetter
 	SignalWrapper<MainFontSetter, void()> fontUpdatedSignal;
 
 private:
-	void SubclassWindowForDpiChanges();
+	void InstallWindowSubclass();
 	LRESULT WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam);
 	void OnDpiChanged();
-	void MaybeSubclassSpecificWindowClasses();
-	LRESULT TooltipWndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam);
 	void UpdateFont();
 
 	HWND m_hwnd;

Explorer++/TestExplorer++/BookmarksToolbarTest.cpp

@@ -7,12 +7,15 @@
 #include "Bookmarks/UI/Views/BookmarksToolbarView.h"
 #include "BrowserTestBase.h"
 #include "BrowserWindowFake.h"
+#include "CustomFont.h"
+#include "FontHelper.h"
 #include "IconFetcherFake.h"
 #include "PidlTestHelper.h"
 #include "ShellBrowser/ShellBrowser.h"
 #include "ShellBrowser/ShellNavigationController.h"
 #include <boost/range/combine.hpp>
 #include <gtest/gtest.h>
+#include <uxtheme.h>
 
 class BookmarksToolbarTest : public BrowserTestBase
 {
@@ -138,3 +141,54 @@ TEST_F(BookmarksToolbarTest, OpenBookmarkOnClick)
 		EXPECT_EQ(currentEntry->GetPidl(), CreateSimplePidlForTest(bookmark->GetLocation()));
 	}
 }
+
+class BookmarksToolbarFontTest : public BrowserTestBase
+{
+protected:
+	BookmarksToolbarFontTest() :
+		m_browser(AddBrowser()),
+		m_bookmarksToolbarView(CreateBookmarksToolbarView(m_browser->GetHWND(), &m_config))
+	{
+		m_bookmarkTree.AddBookmarkItem(m_bookmarkTree.GetBookmarksToolbarFolder(),
+			std::make_unique<BookmarkItem>(std::nullopt, L"Bookmark", L"c:\\path"));
+
+		m_bookmarksToolbar =
+			BookmarksToolbar::Create(m_bookmarksToolbarView, m_browser, &m_acceleratorManager,
+				&m_resourceLoader, &m_iconFetcher, &m_bookmarkTree, &m_platformContext);
+	}
+
+	static BookmarksToolbarView *CreateBookmarksToolbarView(HWND parent, Config *config)
+	{
+		config->mainFont = CustomFont(L"Segoe UI", 15);
+		return BookmarksToolbarView::Create(parent, config);
+	}
+
+	IconFetcherFake m_iconFetcher;
+	BrowserWindowFake *const m_browser;
+	BookmarksToolbarView *const m_bookmarksToolbarView;
+	BookmarksToolbar *m_bookmarksToolbar = nullptr;
+};
+
+TEST_F(BookmarksToolbarFontTest, UsesConfiguredFontOnStartup)
+{
+	// The theme is applied after the main window and all its child controls have been created.
+	ASSERT_TRUE(SUCCEEDED(SetWindowTheme(m_bookmarksToolbarView->GetHWND(), L"", nullptr)));
+
+	auto toolbarFont = reinterpret_cast<HFONT>(
+		SendMessage(m_bookmarksToolbarView->GetHWND(), WM_GETFONT, 0, 0));
+	ASSERT_NE(toolbarFont, nullptr);
+
+	LOGFONT toolbarLogFont;
+	ASSERT_EQ(GetObject(toolbarFont, sizeof(toolbarLogFont), &toolbarLogFont),
+		static_cast<int>(sizeof(toolbarLogFont)));
+
+	auto expectedFont = CreateFontFromNameAndSize(L"Segoe UI", 15,
+		m_bookmarksToolbarView->GetHWND());
+	ASSERT_NE(expectedFont, nullptr);
+
+	LOGFONT expectedLogFont;
+	ASSERT_EQ(GetObject(expectedFont.get(), sizeof(expectedLogFont), &expectedLogFont),
+		static_cast<int>(sizeof(expectedLogFont)));
+
+	EXPECT_EQ(toolbarLogFont, expectedLogFont);
+}