framelesshelper/winnativeeventfilter.cpp

421 lines
16 KiB
C++

#include "winnativeeventfilter.h"
#include <QDebug>
#include <QGuiApplication>
#include <QLibrary>
#include <QOperatingSystemVersion>
#include <QWindow>
#include <d2d1.h>
#include <dwmapi.h>
#include <uxtheme.h>
#include <windowsx.h>
#ifndef SM_CXPADDEDBORDER
// Only available since Windows Vista
#define SM_CXPADDEDBORDER 92
#endif
#ifndef WM_NCUAHDRAWCAPTION
// Not documented, only available since Windows Vista
#define WM_NCUAHDRAWCAPTION 0x00AE
#endif
#ifndef WM_NCUAHDRAWFRAME
// Not documented, only available since Windows Vista
#define WM_NCUAHDRAWFRAME 0x00AF
#endif
#ifndef WM_DWMCOMPOSITIONCHANGED
// Only available since Windows 7
#define WM_DWMCOMPOSITIONCHANGED 0x031E
#endif
namespace {
QScopedPointer<WinNativeEventFilter> instance;
bool isWindowTopLevel(HWND handle) {
if (!handle) {
return false;
}
const auto wid = reinterpret_cast<WId>(handle);
const auto topLevelWindows = QGuiApplication::topLevelWindows();
for (auto &&window : qAsConst(topLevelWindows)) {
if (window->handle() && (window->winId() == wid)) {
return true;
}
}
return false;
}
} // namespace
WinNativeEventFilter::WinNativeEventFilter() {
QLibrary shcoreLib(QString::fromUtf8("SHCore"));
if (QOperatingSystemVersion::current() >=
QOperatingSystemVersion::Windows8_1) {
m_GetDpiForMonitor = reinterpret_cast<lpGetDpiForMonitor>(
shcoreLib.resolve("GetDpiForMonitor"));
}
QLibrary user32Lib(QString::fromUtf8("User32"));
// Windows 10, version 1607 (10.0.14393)
if (QOperatingSystemVersion::current() >=
QOperatingSystemVersion(QOperatingSystemVersion::Windows, 10, 0,
14393)) {
m_GetDpiForWindow = reinterpret_cast<lpGetDpiForWindow>(
user32Lib.resolve("GetDpiForWindow"));
m_GetDpiForSystem = reinterpret_cast<lpGetDpiForSystem>(
user32Lib.resolve("GetDpiForSystem"));
m_GetSystemMetricsForDpi = reinterpret_cast<lpGetSystemMetricsForDpi>(
user32Lib.resolve("GetSystemMetricsForDpi"));
}
// Windows 10, version 1803 (10.0.17134)
if (QOperatingSystemVersion::current() >=
QOperatingSystemVersion(QOperatingSystemVersion::Windows, 10, 0,
17134)) {
m_GetSystemDpiForProcess = reinterpret_cast<lpGetSystemDpiForProcess>(
user32Lib.resolve("GetSystemDpiForProcess"));
}
}
WinNativeEventFilter::~WinNativeEventFilter() = default;
void WinNativeEventFilter::setup() {
if (instance.isNull()) {
instance.reset(new WinNativeEventFilter);
qApp->installNativeEventFilter(instance.data());
}
}
UINT WinNativeEventFilter::windowDpi(HWND handle) const {
return getDpiForWindow(handle);
}
qreal WinNativeEventFilter::windowDpr(HWND handle) const {
return getDprForWindow(handle);
}
int WinNativeEventFilter::borderWidth(HWND handle) const {
return getSystemMetricsForWindow(handle, SM_CXFRAME) +
getSystemMetricsForWindow(handle, SM_CXPADDEDBORDER);
}
int WinNativeEventFilter::borderHeight(HWND handle) const {
return getSystemMetricsForWindow(handle, SM_CYFRAME) +
getSystemMetricsForWindow(handle, SM_CXPADDEDBORDER);
}
int WinNativeEventFilter::titlebarHeight(HWND handle) const {
return borderHeight(handle) +
getSystemMetricsForWindow(handle, SM_CYCAPTION);
}
#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
bool WinNativeEventFilter::nativeEventFilter(const QByteArray &eventType,
void *message, qintptr *result)
#else
bool WinNativeEventFilter::nativeEventFilter(const QByteArray &eventType,
void *message, long *result)
#endif
{
Q_UNUSED(eventType)
const auto msg = static_cast<LPMSG>(message);
if (!msg->hwnd) {
// Why sometimes the window handle is null? Is it designed to be?
// Anyway, we should skip it in this case.
return false;
}
if (!isWindowTopLevel(msg->hwnd)) {
// Only top level windows can be frameless.
return false;
}
if (!m_windowData.contains(msg->hwnd)) {
m_windowData.insert(msg->hwnd, qMakePair(FALSE, FALSE));
init(msg->hwnd);
}
switch (msg->message) {
case WM_NCCREATE: {
// Work-around a long-existing Windows bug.
const auto userData =
reinterpret_cast<LPCREATESTRUCTW>(msg->lParam)->lpCreateParams;
SetWindowLongPtrW(msg->hwnd, GWLP_USERDATA,
reinterpret_cast<LONG_PTR>(userData));
break;
}
case WM_NCCALCSIZE: {
if (static_cast<BOOL>(msg->wParam)) {
if (IsMaximized(msg->hwnd)) {
const HMONITOR monitor =
MonitorFromWindow(msg->hwnd, MONITOR_DEFAULTTONEAREST);
if (monitor) {
MONITORINFO monitorInfo;
SecureZeroMemory(&monitorInfo, sizeof(monitorInfo));
monitorInfo.cbSize = sizeof(monitorInfo);
GetMonitorInfoW(monitor, &monitorInfo);
auto &params =
*reinterpret_cast<LPNCCALCSIZE_PARAMS>(msg->lParam);
params.rgrc[0] = monitorInfo.rcWork;
}
}
// This line removes the window frame (including the titlebar).
// But the frame shadow is lost at the same time. We'll bring it
// back later.
*result = WVR_REDRAW;
} else {
*result = 0;
}
return true;
}
case WM_DWMCOMPOSITIONCHANGED: {
// Bring the frame shadow back through DWM.
// Don't paint the shadow manually using QPainter or QGraphicsEffect.
handleDwmCompositionChanged(msg->hwnd);
*result = 0;
return true;
}
case WM_NCUAHDRAWCAPTION:
case WM_NCUAHDRAWFRAME: {
// These undocumented messages are sent to draw themed window
// borders. Block them to prevent drawing borders over the client
// area.
*result = 0;
return true;
}
case WM_NCPAINT: {
if (m_windowData.value(msg->hwnd).first) {
break;
} else {
// Only block WM_NCPAINT when composition is disabled. If it's
// blocked when composition is enabled, the window shadow won't
// be drawn.
*result = 0;
return true;
}
}
case WM_NCACTIVATE: {
// DefWindowProc won't repaint the window border if lParam (normally
// a HRGN) is -1.
*result = DefWindowProcW(msg->hwnd, msg->message, msg->wParam, -1);
return true;
}
case WM_NCHITTEST: {
const auto getHTResult = [this, msg]() -> LRESULT {
RECT winRect;
GetWindowRect(msg->hwnd, &winRect);
const LONG ww = qAbs(winRect.right - winRect.left);
const LONG wh = qAbs(winRect.bottom - winRect.top);
POINT mouse = {LONG(GET_X_LPARAM(msg->lParam)),
LONG(GET_Y_LPARAM(msg->lParam))};
ScreenToClient(msg->hwnd, &mouse);
// These values are DPI-aware.
const LONG bw = borderWidth(msg->hwnd);
const LONG bh = borderHeight(msg->hwnd);
const LONG tbh = titlebarHeight(msg->hwnd);
if (IsMaximized(msg->hwnd)) {
if (mouse.y < tbh) {
return HTCAPTION;
}
return HTCLIENT;
}
if (mouse.y < bh) {
if (mouse.x < bw) {
return HTTOPLEFT;
}
if (mouse.x > (ww - bw)) {
return HTTOPRIGHT;
}
return HTTOP;
}
if (mouse.y > (wh - bh)) {
if (mouse.x < bw) {
return HTBOTTOMLEFT;
}
if (mouse.x > (ww - bw)) {
return HTBOTTOMRIGHT;
}
return HTBOTTOM;
}
if (mouse.x < bw) {
return HTLEFT;
}
if (mouse.x > (ww - bw)) {
return HTRIGHT;
}
if (mouse.y < tbh) {
return HTCAPTION;
}
return HTCLIENT;
};
*result = getHTResult();
return true;
}
case WM_GETMINMAXINFO: {
// Don't cover the taskbar when maximized.
const HMONITOR monitor =
MonitorFromWindow(msg->hwnd, MONITOR_DEFAULTTONEAREST);
if (monitor) {
MONITORINFO monitorInfo;
SecureZeroMemory(&monitorInfo, sizeof(monitorInfo));
monitorInfo.cbSize = sizeof(monitorInfo);
GetMonitorInfoW(monitor, &monitorInfo);
const RECT rcWorkArea = monitorInfo.rcWork;
const RECT rcMonitorArea = monitorInfo.rcMonitor;
auto &mmi = *reinterpret_cast<LPMINMAXINFO>(msg->lParam);
mmi.ptMaxPosition.x = qAbs(rcWorkArea.left - rcMonitorArea.left);
mmi.ptMaxPosition.y = qAbs(rcWorkArea.top - rcMonitorArea.top);
mmi.ptMaxSize.x = qAbs(rcWorkArea.right - rcWorkArea.left);
mmi.ptMaxSize.y = qAbs(rcWorkArea.bottom - rcWorkArea.top);
mmi.ptMaxTrackSize.x = mmi.ptMaxSize.x;
mmi.ptMaxTrackSize.y = mmi.ptMaxSize.y;
*result = 0;
return true;
}
break;
}
case WM_SETICON:
case WM_SETTEXT: {
// Disable painting while these messages are handled to prevent them
// from drawing a window caption over the client area, but only when
// composition and theming are disabled. These messages don't paint
// when composition is enabled and blocking WM_NCUAHDRAWCAPTION should
// be enough to prevent painting when theming is enabled.
if (!m_windowData.value(msg->hwnd).first &&
!m_windowData.value(msg->hwnd).second) {
const LONG_PTR oldStyle = GetWindowLongPtrW(msg->hwnd, GWL_STYLE);
// Prevent Windows from drawing the default title bar by temporarily
// toggling the WS_VISIBLE style.
SetWindowLongPtrW(msg->hwnd, GWL_STYLE, oldStyle & ~WS_VISIBLE);
const LRESULT ret = DefWindowProcW(msg->hwnd, msg->message,
msg->wParam, msg->lParam);
SetWindowLongPtrW(msg->hwnd, GWL_STYLE, oldStyle);
*result = ret;
return true;
}
break;
}
case WM_THEMECHANGED: {
const BOOL dwm = m_windowData.value(msg->hwnd).first;
m_windowData[msg->hwnd] = qMakePair(dwm, IsThemeActive());
break;
}
default:
break;
}
return false;
}
void WinNativeEventFilter::init(HWND handle) {
// Make sure our window is a normal application window, we'll remove the
// window frame later in Win32 events, don't use WS_POPUP to do this.
SetWindowLongPtrW(handle, GWL_STYLE, WS_OVERLAPPEDWINDOW);
SetWindowLongPtrW(handle, GWL_EXSTYLE, WS_EX_APPWINDOW | WS_EX_LAYERED);
// Make the window a layered window so the legacy GDI API can be used to
// draw to it without messing up the area on top of the DWM frame. Note:
// This is not necessary if other drawing APIs are used, eg. GDI+, OpenGL,
// Direct2D, Direct3D, DirectComposition, etc.
SetLayeredWindowAttributes(handle, RGB(255, 0, 255), 0, LWA_COLORKEY);
// Make sure our window has the frame shadow.
handleDwmCompositionChanged(handle);
// Tell the window to redraw itself.
SetWindowPos(handle, nullptr, 0, 0, 0, 0,
SWP_FRAMECHANGED | SWP_NOACTIVATE | SWP_NOMOVE |
SWP_NOOWNERZORDER | SWP_NOSIZE | SWP_NOZORDER);
// For debug purposes.
qDebug().noquote() << "Window handle:" << handle;
qDebug().noquote() << "Window DPI:" << windowDpi(handle)
<< "Window DPR:" << windowDpr(handle);
qDebug().noquote() << "Window border width:" << borderWidth(handle)
<< "Window border height:" << borderHeight(handle)
<< "Window titlebar height:" << titlebarHeight(handle);
}
void WinNativeEventFilter::handleDwmCompositionChanged(HWND handle) {
BOOL enabled = FALSE;
DwmIsCompositionEnabled(&enabled);
const BOOL theme = m_windowData.value(handle).second;
m_windowData[handle] = qMakePair(enabled, theme);
WTA_OPTIONS options;
options.dwMask = WTNCA_NODRAWCAPTION | WTNCA_NODRAWICON;
// We should not draw the frame shadow if DWM composition is disabled, in
// other words, a window should not have frame shadow when Windows Aero is
// not enabled.
// Note that, start from Win8, the DWM composition is always enabled and
// can't be disabled.
if (enabled) {
options.dwFlags = WTNCA_NODRAWCAPTION | WTNCA_NODRAWICON;
// The frame shadow is drawn on the non-client area and thus we have to
// make sure the non-client area rendering is enabled first.
const DWMNCRENDERINGPOLICY ncrp = DWMNCRP_ENABLED;
DwmSetWindowAttribute(handle, DWMWA_NCRENDERING_POLICY, &ncrp,
sizeof(ncrp));
// Negative margins have special meaning to
// DwmExtendFrameIntoClientArea. Negative margins create the "sheet of
// glass" effect, where the client area is rendered as a solid surface
// with no window border.
const MARGINS margins = {-1, -1, -1, -1};
DwmExtendFrameIntoClientArea(handle, &margins);
}
SetWindowThemeAttribute(handle, WTA_NONCLIENT, &options, sizeof(options));
}
UINT WinNativeEventFilter::getDpiForWindow(HWND handle) const {
const auto getScreenDpi = [this]() -> UINT {
// Available since Windows 7.
ID2D1Factory *m_pDirect2dFactory = nullptr;
if (SUCCEEDED(D2D1CreateFactory(D2D1_FACTORY_TYPE_SINGLE_THREADED,
&m_pDirect2dFactory)) &&
m_pDirect2dFactory) {
m_pDirect2dFactory->ReloadSystemMetrics();
FLOAT dpiX = m_defaultDPI, dpiY = m_defaultDPI;
m_pDirect2dFactory->GetDesktopDpi(&dpiX, &dpiY);
// The values of *dpiX and *dpiY are identical.
return dpiX;
}
// Available since Windows 2000.
const HDC hdc = GetDC(nullptr);
if (hdc) {
const int dpiX = GetDeviceCaps(hdc, LOGPIXELSX);
const int dpiY = GetDeviceCaps(hdc, LOGPIXELSY);
ReleaseDC(nullptr, hdc);
// The values of dpiX and dpiY are identical actually, just to
// silence a compiler warning.
return dpiX == dpiY ? dpiX : dpiY;
}
return m_defaultDPI;
};
if (!handle) {
if (m_GetSystemDpiForProcess) {
return m_GetSystemDpiForProcess(GetCurrentProcess());
} else if (m_GetDpiForSystem) {
return m_GetDpiForSystem();
} else {
return getScreenDpi();
}
}
if (m_GetDpiForWindow) {
return m_GetDpiForWindow(handle);
}
if (m_GetDpiForMonitor) {
UINT dpiX = m_defaultDPI, dpiY = m_defaultDPI;
m_GetDpiForMonitor(MonitorFromWindow(handle, MONITOR_DEFAULTTONEAREST),
MDT_EFFECTIVE_DPI, &dpiX, &dpiY);
// The values of *dpiX and *dpiY are identical.
return dpiX;
}
return getScreenDpi();
}
qreal WinNativeEventFilter::getDprForWindow(HWND handle) const {
return handle ? (qreal(getDpiForWindow(handle)) / qreal(m_defaultDPI))
: m_defaultDPR;
}
int WinNativeEventFilter::getSystemMetricsForWindow(HWND handle,
int index) const {
if (m_GetSystemMetricsForDpi) {
return m_GetSystemMetricsForDpi(index, getDpiForWindow(handle));
} else {
return GetSystemMetrics(index) * getDprForWindow(handle);
}
}