[AlwaysOnTop] Proof of concept (#14360)

Co-authored-by: Niels Laute <niels.laute@live.nl>

src/modules/alwaysontop/AlwaysOnTop/WindowBorder.cpp

@@ -0,0 +1,223 @@
+#include "pch.h"
+#include "WindowBorder.h"
+
+#include <dwmapi.h>
+
+#include <FrameDrawer.h>
+#include <Settings.h>
+
+// Non-Localizable strings
+namespace NonLocalizable
+{
+    const wchar_t ToolWindowClassName[] = L"AlwaysOnTop_Border";
+}
+
+std::optional<RECT> GetFrameRect(HWND window)
+{
+    RECT rect;
+    if (!SUCCEEDED(DwmGetWindowAttribute(window, DWMWA_EXTENDED_FRAME_BOUNDS, &rect, sizeof(rect))))
+    {
+        return std::nullopt;
+    }
+
+    int border = static_cast<int>(AlwaysOnTopSettings::settings().frameThickness / 2);
+    rect.top -= border;
+    rect.left -= border;
+    rect.right += border;
+    rect.bottom += border;
+
+    return rect;
+}
+
+WindowBorder::WindowBorder(HWND window) :
+    SettingsObserver({SettingId::FrameColor, SettingId::FrameThickness}),
+    m_window(nullptr), 
+    m_trackingWindow(window), 
+    m_frameDrawer(nullptr)
+{
+}
+
+WindowBorder::WindowBorder(WindowBorder&& other) :
+    SettingsObserver({ SettingId::FrameColor, SettingId::FrameThickness }),
+    m_window(other.m_window), 
+    m_trackingWindow(other.m_trackingWindow), 
+    m_frameDrawer(std::move(other.m_frameDrawer))
+{
+}
+
+WindowBorder::~WindowBorder()
+{
+    if (m_frameDrawer)
+    {
+        m_frameDrawer->Hide();
+        m_frameDrawer = nullptr;
+    }
+
+    if (m_window)
+    {
+        SetWindowLongPtrW(m_window, GWLP_USERDATA, 0);
+        ShowWindow(m_window, SW_HIDE);
+    }
+}
+
+bool WindowBorder::Init(HINSTANCE hinstance)
+{
+    if (!m_trackingWindow)
+    {
+        return false;
+    }
+
+    auto windowRectOpt = GetFrameRect(m_trackingWindow);
+    if (!windowRectOpt.has_value())
+    {
+        return false;
+    }
+
+    RECT windowRect = windowRectOpt.value();
+
+    WNDCLASSEXW wcex{};
+    wcex.cbSize = sizeof(WNDCLASSEX);
+    wcex.lpfnWndProc = s_WndProc;
+    wcex.hInstance = hinstance;
+    wcex.lpszClassName = NonLocalizable::ToolWindowClassName;
+    wcex.hCursor = LoadCursorW(nullptr, IDC_ARROW);
+    RegisterClassExW(&wcex);
+
+    m_window = CreateWindowExW(WS_EX_LAYERED | WS_EX_TOPMOST | WS_EX_TOOLWINDOW
+        , NonLocalizable::ToolWindowClassName
+        , L""
+        , WS_POPUP
+        , windowRect.left
+        , windowRect.top
+        , windowRect.right - windowRect.left
+        , windowRect.bottom - windowRect.top
+        , nullptr
+        , nullptr
+        , hinstance
+        , this);
+
+    if (!m_window)
+    {
+        return false;
+    }
+
+    if (!SetLayeredWindowAttributes(m_window, RGB(0, 0, 0), 0, LWA_COLORKEY))
+    {
+        return false;
+    }
+
+    // set position of the border-window behind the tracking window
+    // helps to prevent border overlapping (happens after turning borders off and on)
+    SetWindowPos(m_trackingWindow
+        , m_window
+        , windowRect.left
+        , windowRect.top
+        , windowRect.right - windowRect.left - static_cast<int>(AlwaysOnTopSettings::settings().frameThickness)
+        , windowRect.bottom - windowRect.top - static_cast<int>(AlwaysOnTopSettings::settings().frameThickness)
+        , SWP_NOMOVE | SWP_NOSIZE);
+
+    m_frameDrawer = FrameDrawer::Create(m_window);
+    return m_frameDrawer != nullptr;
+}
+
+void WindowBorder::UpdateBorderPosition() const
+{
+    if (!m_trackingWindow)
+    {
+        return;
+    }
+
+    auto rectOpt = GetFrameRect(m_trackingWindow);
+    if (!rectOpt.has_value())
+    {
+        return;
+    }
+
+    RECT rect = rectOpt.value();
+    SetWindowPos(m_window, m_trackingWindow, rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top, SWP_NOREDRAW);
+}
+
+void WindowBorder::UpdateBorderProperties() const
+{
+    if (!m_trackingWindow || !m_frameDrawer)
+    {
+        return;
+    }
+
+    auto windowRectOpt = GetFrameRect(m_trackingWindow);
+    if (!windowRectOpt.has_value())
+    {
+        return;
+    }
+
+    RECT windowRect = windowRectOpt.value();
+    RECT frameRect{ 0, 0, windowRect.right - windowRect.left, windowRect.bottom - windowRect.top };
+    m_frameDrawer->SetBorderRect(frameRect, AlwaysOnTopSettings::settings().frameColor, AlwaysOnTopSettings::settings().frameThickness);
+}
+
+void WindowBorder::Show() const
+{
+    UpdateBorderProperties();
+    m_frameDrawer->Show();
+}
+
+void WindowBorder::Hide() const
+{
+    m_frameDrawer->Hide();
+}
+
+LRESULT WindowBorder::WndProc(UINT message, WPARAM wparam, LPARAM lparam) noexcept
+{
+    switch (message)
+    {
+    case WM_NCDESTROY:
+    {
+        ::DefWindowProc(m_window, message, wparam, lparam);
+        SetWindowLongPtr(m_window, GWLP_USERDATA, 0);
+    }
+    break;
+
+    case WM_ERASEBKGND:
+        return TRUE;
+
+    default:
+    {
+        return DefWindowProc(m_window, message, wparam, lparam);
+    }
+    }
+    return FALSE;
+}
+
+void WindowBorder::SettingsUpdate(SettingId id)
+{
+    if (!AlwaysOnTopSettings::settings().enableFrame)
+    {
+        return;
+    }
+
+    auto windowRectOpt = GetFrameRect(m_trackingWindow);
+    if (!windowRectOpt.has_value())
+    {
+        return;
+    }
+
+    switch (id)
+    {
+    case SettingId::FrameThickness:
+    {
+        UpdateBorderPosition();
+        UpdateBorderProperties();
+    }
+    break;
+    
+    case SettingId::FrameColor:
+    {
+        UpdateBorderProperties();
+    }
+    break;
+
+    default:
+        break;
+    }
+    
+}