Support nebula:// internal pages & GPU tools

Introduce support for an internal nebula:// URL scheme and internal page routing (ResolveInternalUrl / ToInternalUrl), including dedicated slugs for home, settings, downloads, big-picture, gpu-diagnostics, insecure and a 404 fallback. Wire internal resolution into browser creation and tab navigation so internal pages load from local UI files. Add an insecure-warning interstitial flow with a navigate-insecure command and a one-shot bypass set (ShouldBypassInsecureWarning) so content can request navigating to an HTTP target after user confirmation. Harden BrowserClient handling to resolve Chromium new-tab and nebula internal URLs, redirect HTTP to the insecure warning when appropriate, and handle 404 responses by loading the internal 404 page. Update chrome UI behavior to hide internal home URLs, accept nebula:// in navigation input checks, and add a GPU Diagnostics page (revamped UI + diagnostic scripts) plus menu entry. Misc: improve URL utilities (scheme checks, percent-encoding, decorations), fix 404 display text, adjust menu popup size, tweak window frame styling (DWM attributes) and remove branding block from chrome UI CSS.

src/app/nebula_controller.cpp

@@ -55,7 +55,7 @@ RECT MenuPopupRect(HWND hwnd, const nebula::window::BrowserLayout& layout) {
     GetClientRect(hwnd, &client);
 
     const int width = ScaleForWindow(hwnd, 260);
-    const int height = ScaleForWindow(hwnd, 218);
+    const int height = ScaleForWindow(hwnd, 258);
     const int margin = ScaleForWindow(hwnd, 12);
     const int overlap = ScaleForWindow(hwnd, 2);
 
@@ -103,6 +103,10 @@ std::string WithCacheBuster(std::string url) {
     return url + separator + "nebula_cache_bust=" + std::to_string(GetTickCount64()) + fragment;
 }
 
+std::string GetChromeDisplayUrl(const std::string& url) {
+    return nebula::ui::IsInternalHomeUrl(url) ? std::string{} : url;
+}
+
 void SetBrowserVisible(CefRefPtr<CefBrowser> browser, bool visible) {
     if (!browser) {
         return;
@@ -209,6 +213,12 @@ void NebulaController::OnBrowserClosing(nebula::cef::BrowserRole role, CefRefPtr
 void NebulaController::OnChromeCommand(const std::string& command, const std::string& payload) {
     if (command == "navigate") {
         tabs_.LoadURL(payload);
+    } else if (command == "navigate-insecure") {
+        const std::string target = nebula::browser::NormalizeNavigationInput(payload);
+        if (nebula::ui::IsHttpUrl(target)) {
+            insecure_warning_bypasses_.insert(target);
+            tabs_.LoadURL(target);
+        }
     } else if (command == "new-tab") {
         CreateNewTab();
     } else if (command == "activate-tab") {
@@ -233,6 +243,9 @@ void NebulaController::OnChromeCommand(const std::string& command, const std::st
     } else if (command == "big-picture") {
         CloseMenuPopup();
         tabs_.LoadURL(nebula::ui::GetBigPictureUrl());
+    } else if (command == "gpu-diagnostics") {
+        CloseMenuPopup();
+        tabs_.LoadURL(nebula::ui::GetGpuDiagnosticsUrl());
     } else if (command == "toggle-devtools") {
         ToggleDevTools();
     } else if (command == "zoom-out") {
@@ -263,7 +276,10 @@ void NebulaController::OnChromeCommand(const std::string& command, const std::st
 }
 
 void NebulaController::OnContentAddressChanged(CefRefPtr<CefBrowser> browser, const std::string& url) {
-    tabs_.UpdateURL(browser, nebula::ui::IsChromiumNewTabUrl(url) ? nebula::ui::GetHomeUrl() : url);
+    tabs_.UpdateURL(browser,
+                    nebula::ui::IsChromiumNewTabUrl(url)
+                        ? nebula::ui::GetHomeUrl()
+                        : nebula::ui::ToInternalUrl(url));
 }
 
 void NebulaController::OnContentTitleChanged(CefRefPtr<CefBrowser> browser, const std::string& title) {
@@ -296,6 +312,20 @@ void NebulaController::OnPopupRequested(CefRefPtr<CefBrowser> browser, const std
                       : target_url);
 }
 
+bool NebulaController::ShouldBypassInsecureWarning(CefRefPtr<CefBrowser> browser, const std::string& target_url) {
+    if (!tabs_.OwnsBrowser(browser)) {
+        return false;
+    }
+
+    const auto bypass = insecure_warning_bypasses_.find(target_url);
+    if (bypass == insecure_warning_bypasses_.end()) {
+        return false;
+    }
+
+    insecure_warning_bypasses_.erase(bypass);
+    return true;
+}
+
 void NebulaController::CreateNewTab() {
     if (auto* tab = tabs_.ActiveTab()) {
         SetBrowserVisible(tab->browser, false);
@@ -376,7 +406,8 @@ void NebulaController::CreateContentBrowser() {
     CefBrowserSettings browser_settings;
     content_client_ = new nebula::cef::NebulaBrowserClient(nebula::cef::BrowserRole::Content, this);
     CefWindowInfo window_info = ChildWindowInfo(window_->hwnd(), layout.content);
-    CefBrowserHost::CreateBrowser(window_info, content_client_, url, browser_settings, nullptr, nullptr);
+    CefBrowserHost::CreateBrowser(
+        window_info, content_client_, nebula::ui::ResolveInternalUrl(url), browser_settings, nullptr, nullptr);
 }
 
 void NebulaController::ToggleMenuPopup() {
@@ -476,6 +507,7 @@ void NebulaController::SendChromeState(const nebula::browser::NebulaTab& tab) {
         return;
     }
 
+    const std::string display_url = GetChromeDisplayUrl(tab.url);
     std::string tabs_json = "[";
     const auto& tabs = tabs_.Tabs();
     for (size_t i = 0; i < tabs.size(); ++i) {
@@ -495,7 +527,7 @@ void NebulaController::SendChromeState(const nebula::browser::NebulaTab& tab) {
     const std::string script =
         "window.NebulaChrome && window.NebulaChrome.applyState({"
         "\"id\":" + std::to_string(tab.id) +
-        ",\"url\":\"" + nebula::browser::JsonEscape(tab.url) + "\""
+        ",\"url\":\"" + nebula::browser::JsonEscape(display_url) + "\""
         ",\"title\":\"" + nebula::browser::JsonEscape(tab.title) + "\""
         ",\"isLoading\":" + std::string(tab.is_loading ? "true" : "false") +
         ",\"progress\":" + std::to_string(tab.load_progress) +

src/app/nebula_controller.h

@@ -2,6 +2,7 @@
 
 #include <memory>
 #include <string>
+#include <unordered_set>
 #include <vector>
 
 #include "browser/tab_manager.h"
@@ -34,6 +35,7 @@ public:
     void OnContentLoadProgressChanged(CefRefPtr<CefBrowser> browser, double progress) override;
     void OnContentFaviconChanged(CefRefPtr<CefBrowser> browser, const std::vector<std::string>& urls) override;
     void OnPopupRequested(CefRefPtr<CefBrowser> browser, const std::string& target_url) override;
+    bool ShouldBypassInsecureWarning(CefRefPtr<CefBrowser> browser, const std::string& target_url) override;
 
 private:
     void CreateNewTab();
@@ -65,6 +67,7 @@ private:
     CefRefPtr<nebula::cef::NebulaBrowserClient> chrome_client_;
     CefRefPtr<nebula::cef::NebulaBrowserClient> content_client_;
     CefRefPtr<nebula::cef::NebulaBrowserClient> menu_popup_client_;
+    std::unordered_set<std::string> insecure_warning_bypasses_;
 };
 
 }  // namespace nebula::app

src/browser/tab_manager.cpp

@@ -1,6 +1,7 @@
 #include "browser/tab_manager.h"
 
 #include "browser/url_utils.h"
+#include "ui/paths.h"
 
 namespace nebula::browser {
 
@@ -134,7 +135,7 @@ void TabManager::LoadURL(const std::string& input) {
 
     tab->url = target;
     tab->favicon_url.clear();
-    tab->browser->GetMainFrame()->LoadURL(target);
+    tab->browser->GetMainFrame()->LoadURL(nebula::ui::ResolveInternalUrl(target));
     Notify();
 }
 

src/browser/url_utils.cpp

@@ -1,5 +1,6 @@
 #include "browser/url_utils.h"
 
+#include <algorithm>
 #include <cctype>
 #include <iomanip>
 #include <sstream>
@@ -19,13 +20,17 @@ std::string Trim(std::string value) {
     return value;
 }
 
-bool StartsWithScheme(const std::string& value) {
+bool StartsWithScheme(std::string value) {
+    std::transform(value.begin(), value.end(), value.begin(), [](unsigned char ch) {
+        return static_cast<char>(std::tolower(ch));
+    });
     return value.starts_with("http://") ||
            value.starts_with("https://") ||
            value.starts_with("file:") ||
            value.starts_with("data:") ||
            value.starts_with("blob:") ||
-           value.starts_with("chrome:");
+           value.starts_with("chrome:") ||
+           value.starts_with("nebula://");
 }
 
 bool LooksLikeHostName(const std::string& value) {

src/cef/browser_client.cpp

@@ -9,6 +9,14 @@ namespace {
 
 constexpr char kChromeCommandMessage[] = "NebulaChromeCommand";
 
+bool IsInsecureInterstitialFrame(CefRefPtr<CefFrame> frame) {
+    if (!frame) {
+        return false;
+    }
+
+    return nebula::ui::ToInternalUrl(frame->GetURL().ToString()).starts_with("nebula://insecure");
+}
+
 std::vector<std::string> ToStringVector(const std::vector<CefString>& values) {
     std::vector<std::string> result;
     result.reserve(values.size());
@@ -29,17 +37,25 @@ bool NebulaBrowserClient::OnProcessMessageReceived(CefRefPtr<CefBrowser> browser
                                                    CefRefPtr<CefProcessMessage> message) {
     CEF_REQUIRE_UI_THREAD();
     UNREFERENCED_PARAMETER(browser);
-    UNREFERENCED_PARAMETER(frame);
     UNREFERENCED_PARAMETER(source_process);
 
-    if ((role_ != BrowserRole::Chrome && role_ != BrowserRole::MenuPopup) || !message ||
-        message->GetName().ToString() != kChromeCommandMessage) {
+    if (!message || message->GetName().ToString() != kChromeCommandMessage) {
+        return false;
+    }
+
+    if (role_ != BrowserRole::Chrome && role_ != BrowserRole::MenuPopup &&
+        role_ != BrowserRole::Content) {
         return false;
     }
 
     CefRefPtr<CefListValue> args = message->GetArgumentList();
     const std::string command = args && args->GetSize() > 0 ? args->GetString(0).ToString() : "";
     const std::string payload = args && args->GetSize() > 1 ? args->GetString(1).ToString() : "";
+    if (role_ == BrowserRole::Content &&
+        (command != "navigate-insecure" || !IsInsecureInterstitialFrame(frame))) {
+        return false;
+    }
+
     if (delegate_ && !command.empty()) {
         delegate_->OnChromeCommand(command, payload);
         return true;
@@ -172,9 +188,14 @@ void NebulaBrowserClient::OnLoadEnd(CefRefPtr<CefBrowser> browser,
                                     CefRefPtr<CefFrame> frame,
                                     int httpStatusCode) {
     CEF_REQUIRE_UI_THREAD();
-    UNREFERENCED_PARAMETER(httpStatusCode);
 
     if (role_ == BrowserRole::Content && delegate_ && frame && frame->IsMain()) {
+        if (httpStatusCode == 404) {
+            frame->LoadURL(nebula::ui::ResolveInternalUrl(
+                nebula::ui::GetNotFoundUrl(frame->GetURL().ToString())));
+            return;
+        }
+
         delegate_->OnContentLoadProgressChanged(browser, 1.0);
     }
 }
@@ -189,10 +210,24 @@ bool NebulaBrowserClient::OnBeforeBrowse(CefRefPtr<CefBrowser> browser,
     UNREFERENCED_PARAMETER(user_gesture);
     UNREFERENCED_PARAMETER(is_redirect);
 
-    if (role_ == BrowserRole::Content && frame && frame->IsMain() && request &&
-        nebula::ui::IsChromiumNewTabUrl(request->GetURL().ToString())) {
-        frame->LoadURL(nebula::ui::GetHomeUrl());
-        return true;
+    if (role_ == BrowserRole::Content && frame && frame->IsMain() && request) {
+        const std::string url = request->GetURL().ToString();
+        if (nebula::ui::IsChromiumNewTabUrl(url)) {
+            frame->LoadURL(nebula::ui::ResolveInternalUrl(nebula::ui::GetHomeUrl()));
+            return true;
+        }
+
+        if (nebula::ui::IsNebulaInternalUrl(url)) {
+            frame->LoadURL(nebula::ui::ResolveInternalUrl(url));
+            return true;
+        }
+
+        if (nebula::ui::IsHttpUrl(url) &&
+            (!delegate_ || !delegate_->ShouldBypassInsecureWarning(browser, url))) {
+            frame->LoadURL(nebula::ui::ResolveInternalUrl(
+                nebula::ui::GetInsecureWarningUrl(url)));
+            return true;
+        }
     }
 
     return false;

src/cef/browser_client.h

@@ -31,6 +31,7 @@ public:
     virtual void OnContentLoadProgressChanged(CefRefPtr<CefBrowser> browser, double progress) = 0;
     virtual void OnContentFaviconChanged(CefRefPtr<CefBrowser> browser, const std::vector<std::string>& urls) = 0;
     virtual void OnPopupRequested(CefRefPtr<CefBrowser> browser, const std::string& target_url) = 0;
+    virtual bool ShouldBypassInsecureWarning(CefRefPtr<CefBrowser> browser, const std::string& target_url) = 0;
 };
 
 class NebulaBrowserClient final : public CefClient,

src/ui/paths.cpp

@@ -4,10 +4,31 @@
 
 #include <algorithm>
 #include <cctype>
+#include <string_view>
 
 namespace nebula::ui {
 namespace {
 
+constexpr std::string_view kNebulaScheme = "nebula://";
+constexpr std::wstring_view kInternalFallbackPage = L"404.html";
+
+struct InternalPage {
+    std::string_view slug;
+    std::wstring_view file_name;
+};
+
+constexpr InternalPage kInternalPages[] = {
+    {"home", L"home.html"},
+    {"settings", L"settings.html"},
+    {"downloads", L"downloads.html"},
+    {"bigpicture", L"bigpicture.html"},
+    {"big-picture", L"bigpicture.html"},
+    {"gpu-diagnostics", L"gpu-diagnostics.html"},
+    {"setup", L"setup.html"},
+    {"404", L"404.html"},
+    {"insecure", L"insecure.html"},
+};
+
 std::string WideToUtf8(const std::wstring& value) {
     if (value.empty()) {
         return {};
@@ -31,6 +52,11 @@ std::string GetUrlWithoutDecoration(std::string url) {
     return url;
 }
 
+std::string GetUrlDecoration(const std::string& url) {
+    const size_t split = url.find_first_of("?#");
+    return split == std::string::npos ? std::string{} : url.substr(split);
+}
+
 std::string ToLowerAscii(std::string value) {
     std::transform(value.begin(), value.end(), value.begin(), [](unsigned char ch) {
         return static_cast<char>(std::tolower(ch));
@@ -38,6 +64,66 @@ std::string ToLowerAscii(std::string value) {
     return value;
 }
 
+std::string PageFileUrl(std::wstring_view page_name) {
+    const auto path = GetUiPagePath(std::wstring(page_name));
+    return path.empty() ? std::string{} : FilePathToUrl(path);
+}
+
+std::string PercentEncode(const std::string& value) {
+    constexpr char kHex[] = "0123456789ABCDEF";
+    std::string encoded;
+    encoded.reserve(value.size());
+    for (unsigned char ch : value) {
+        if (std::isalnum(ch) || ch == '-' || ch == '_' || ch == '.' || ch == '~') {
+            encoded += static_cast<char>(ch);
+        } else {
+            encoded += '%';
+            encoded += kHex[ch >> 4];
+            encoded += kHex[ch & 0x0F];
+        }
+    }
+    return encoded;
+}
+
+std::string InternalPageName(const std::string& url) {
+    std::string target = ToLowerAscii(GetUrlWithoutDecoration(url));
+    if (!target.starts_with(kNebulaScheme)) {
+        return {};
+    }
+
+    target.erase(0, kNebulaScheme.size());
+    while (!target.empty() && target.front() == '/') {
+        target.erase(target.begin());
+    }
+    while (!target.empty() && target.back() == '/') {
+        target.pop_back();
+    }
+    return target.empty() ? "home" : target;
+}
+
+std::string InternalUrlForSlug(std::string_view slug) {
+    return std::string(kNebulaScheme) + std::string(slug);
+}
+
+const InternalPage* FindInternalPageBySlug(std::string_view slug) {
+    for (const auto& page : kInternalPages) {
+        if (page.slug == slug) {
+            return &page;
+        }
+    }
+    return nullptr;
+}
+
+const InternalPage* FindInternalPageByFileUrl(const std::string& url) {
+    const std::string base_url = GetUrlWithoutDecoration(url);
+    for (const auto& page : kInternalPages) {
+        if (PageFileUrl(page.file_name) == base_url) {
+            return &page;
+        }
+    }
+    return nullptr;
+}
+
 }  // namespace
 
 std::filesystem::path GetExecutableDirectory() {
@@ -77,31 +163,85 @@ std::string FilePathToUrl(std::filesystem::path path) {
 
 std::string GetChromeUrl() {
     const auto path = GetUiPagePath(L"chrome.html");
-    return path.empty() ? GetHomeUrl() : FilePathToUrl(path);
+    const std::string fallback = PageFileUrl(L"home.html");
+    return path.empty() ? (fallback.empty() ? "https://www.google.com" : fallback) : FilePathToUrl(path);
 }
 
 std::string GetHomeUrl() {
-    const auto path = GetUiPagePath(L"home.html");
-    return path.empty() ? "https://www.google.com" : FilePathToUrl(path);
+    return InternalUrlForSlug("home");
 }
 
 std::string GetSettingsUrl() {
-    const auto path = GetUiPagePath(L"settings.html");
-    return path.empty() ? GetHomeUrl() : FilePathToUrl(path);
+    return InternalUrlForSlug("settings");
+}
+
+std::string GetDownloadsUrl() {
+    return InternalUrlForSlug("downloads");
 }
 
 std::string GetBigPictureUrl() {
-    const auto path = GetUiPagePath(L"bigpicture.html");
-    return path.empty() ? GetHomeUrl() : FilePathToUrl(path);
+    return InternalUrlForSlug("bigpicture");
+}
+
+std::string GetGpuDiagnosticsUrl() {
+    return InternalUrlForSlug("gpu-diagnostics");
 }
 
 std::string GetMenuPopupUrl() {
     const auto path = GetUiPagePath(L"menu-popup.html");
-    return path.empty() ? GetHomeUrl() : FilePathToUrl(path);
+    const std::string fallback = PageFileUrl(L"home.html");
+    return path.empty() ? (fallback.empty() ? "https://www.google.com" : fallback) : FilePathToUrl(path);
+}
+
+std::string GetInsecureWarningUrl(const std::string& target_url) {
+    return InternalUrlForSlug("insecure") + "?target=" + PercentEncode(target_url);
+}
+
+std::string GetNotFoundUrl(const std::string& target_url) {
+    return InternalUrlForSlug("404") + "?url=" + PercentEncode(target_url);
+}
+
+std::string ResolveInternalUrl(const std::string& url) {
+    const std::string page_name = InternalPageName(url);
+    if (page_name.empty()) {
+        return url;
+    }
+
+    if (const auto* page = FindInternalPageBySlug(page_name)) {
+        const std::string file_url = PageFileUrl(page->file_name);
+        return file_url.empty() ? url : file_url + GetUrlDecoration(url);
+    }
+
+    const std::string fallback_url = PageFileUrl(kInternalFallbackPage);
+    return fallback_url.empty() ? url : fallback_url + "?url=" + PercentEncode(url);
+}
+
+std::string ToInternalUrl(const std::string& url) {
+    const std::string page_name = InternalPageName(url);
+    if (!page_name.empty()) {
+        if (const auto* page = FindInternalPageBySlug(page_name)) {
+            return InternalUrlForSlug(page->slug) + GetUrlDecoration(url);
+        }
+        return url;
+    }
+
+    if (const auto* page = FindInternalPageByFileUrl(url)) {
+        return InternalUrlForSlug(page->slug) + GetUrlDecoration(url);
+    }
+
+    return url;
 }
 
 bool IsInternalHomeUrl(const std::string& url) {
-    return GetUrlWithoutDecoration(url) == GetHomeUrl();
+    return GetUrlWithoutDecoration(ToInternalUrl(url)) == GetHomeUrl();
+}
+
+bool IsNebulaInternalUrl(const std::string& url) {
+    return ToLowerAscii(url).starts_with(kNebulaScheme);
+}
+
+bool IsHttpUrl(const std::string& url) {
+    return ToLowerAscii(url).starts_with("http://");
 }
 
 bool IsChromiumNewTabUrl(const std::string& url) {

src/ui/paths.h

@@ -11,10 +11,18 @@ std::string FilePathToUrl(std::filesystem::path path);
 std::string GetChromeUrl();
 std::string GetHomeUrl();
 std::string GetSettingsUrl();
+std::string GetDownloadsUrl();
 std::string GetBigPictureUrl();
+std::string GetGpuDiagnosticsUrl();
 std::string GetMenuPopupUrl();
+std::string GetInsecureWarningUrl(const std::string& target_url);
+std::string GetNotFoundUrl(const std::string& target_url);
+std::string ResolveInternalUrl(const std::string& url);
+std::string ToInternalUrl(const std::string& url);
 
 bool IsInternalHomeUrl(const std::string& url);
+bool IsNebulaInternalUrl(const std::string& url);
+bool IsHttpUrl(const std::string& url);
 bool IsChromiumNewTabUrl(const std::string& url);
 bool IsEmptyOrChromiumNewTabUrl(const std::string& url);
 

src/window/nebula_window.cpp

@@ -15,6 +15,7 @@ constexpr wchar_t kChildFrameHitTestParentProp[] = L"NebulaChildFrameHitTestPare
 constexpr int kTitleRowHeightDip = 42;
 constexpr int kWindowControlWidthDip = 46;
 constexpr int kWindowControlCount = 3;
+constexpr COLORREF kNoWindowBorderColor = 0xFFFFFFFE;
 
 RECT GetWorkArea() {
     RECT work_area = {};
@@ -56,6 +57,28 @@ bool SetResizeCursor(LRESULT hit) {
     return true;
 }
 
+void ApplyWindowFrameStyle(HWND hwnd) {
+    const BOOL dark_mode = TRUE;
+    const DWM_WINDOW_CORNER_PREFERENCE corner_preference = DWMWCP_ROUND;
+    DwmSetWindowAttribute(
+        hwnd,
+        DWMWA_USE_IMMERSIVE_DARK_MODE,
+        &dark_mode,
+        sizeof(dark_mode));
+
+    DwmSetWindowAttribute(
+        hwnd,
+        DWMWA_WINDOW_CORNER_PREFERENCE,
+        &corner_preference,
+        sizeof(corner_preference));
+
+    DwmSetWindowAttribute(
+        hwnd,
+        DWMWA_BORDER_COLOR,
+        &kNoWindowBorderColor,
+        sizeof(kNoWindowBorderColor));
+}
+
 }  // namespace
 
 NebulaWindow::NebulaWindow(WindowDelegate* delegate) : delegate_(delegate) {}
@@ -92,8 +115,9 @@ bool NebulaWindow::Create(HINSTANCE instance, int show_command) {
     }
 
     UpdateDpi();
+    ApplyWindowFrameStyle(hwnd_);
 
-    const MARGINS margins = {1, 1, 1, 1};
+    const MARGINS margins = {0, 0, 0, 0};
     DwmExtendFrameIntoClientArea(hwnd_, &margins);
 
     ShowWindow(hwnd_, show_command);
@@ -265,6 +289,10 @@ LRESULT NebulaWindow::WndProc(UINT message, WPARAM wparam, LPARAM lparam) {
             }
             break;
 
+        case WM_NCACTIVATE:
+            ApplyWindowFrameStyle(hwnd_);
+            return TRUE;
+
         case WM_ERASEBKGND:
             return 1;