framelesshelper/winnativeeventfilter.h

/*
 * MIT License
 *
 * Copyright (C) 2020 by wangwenx190 (Yuhang Zhao)
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#pragma once

#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif

#include <QAbstractNativeEventFilter>
#include <QPointer>
#include <QRect>
#include <QVector>
#include <qt_windows.h>

QT_BEGIN_NAMESPACE
QT_FORWARD_DECLARE_CLASS(QWindow)
QT_END_NAMESPACE

#if (QT_VERSION < QT_VERSION_CHECK(5, 13, 0))
#define Q_DISABLE_MOVE(Class)                                                  \
    Class(Class &&) = delete;                                                  \
    Class &operator=(Class &&) = delete;

#define Q_DISABLE_COPY_MOVE(Class)                                             \
    Q_DISABLE_COPY(Class)                                                      \
    Q_DISABLE_MOVE(Class)
#endif

class WinNativeEventFilter : public QAbstractNativeEventFilter {
    Q_DISABLE_COPY_MOVE(WinNativeEventFilter)

public:
    using WINDOWDATA = struct _WINDOWDATA {
        BOOL fixedSize = FALSE, mouseTransparent = FALSE,
             restoreDefaultWindowStyles = FALSE,
             doNotEnableLayeredWindow = FALSE;
        int borderWidth = -1, borderHeight = -1, titleBarHeight = -1;
        QVector<QRect> ignoreAreas = {}, draggableAreas = {};
        QVector<QPointer<QObject>> ignoreObjects = {}, draggableObjects = {};
        QSize maximumSize = {-1, -1}, minimumSize = {-1, -1};
    };

    using WINDOW = struct _WINDOW {
        HWND hWnd = nullptr;
        BOOL initialized = FALSE;
        WINDOWDATA windowData;
    };

    enum class SystemMetric { BorderWidth, BorderHeight, TitleBarHeight };

    explicit WinNativeEventFilter();
    ~WinNativeEventFilter() override;

    // Frameless windows handle list
    static QVector<HWND> framelessWindows();
    static void setFramelessWindows(const QVector<HWND> &windows);
    // Make the given window become frameless.
    // The width and height will be scaled automatically according to DPI. Don't
    // scale them yourself. Just pass the original value. If you don't want to
    // change them, pass negative values to the parameters.
    static void addFramelessWindow(const HWND window,
                                   const WINDOWDATA *data = nullptr,
                                   const bool center = false, const int x = -1,
                                   const int y = -1, const int width = -1,
                                   const int height = -1);
    static void removeFramelessWindow(const HWND window);
    static void clearFramelessWindows();

    // Set borderWidth, borderHeight or titleBarHeight to a negative value to
    // restore default behavior.
    // Note that it can only affect one specific window.
    // If you want to change these values globally, use setBorderWidth instead.
    static void setWindowData(const HWND window, const WINDOWDATA *data);
    // You can modify the given window's data directly, it's the same with using
    // setWindowData.
    static WINDOWDATA *windowData(const HWND window);

    // Change settings globally, not a specific window.
    // These values will be scaled automatically according to DPI, don't scale
    // them yourself. Just pass the original value.
    static void setBorderWidth(const int bw);
    static void setBorderHeight(const int bh);
    static void setTitleBarHeight(const int tbh);

    // System metric value of the given window (if the pointer is null,
    // return the system's standard value).
    static int getSystemMetric(const HWND handle, const SystemMetric metric,
                               const bool dpiAware = true);

    // Use this function to trigger a frame change event or redraw a
    // specific window. Useful when you want to let some changes
    // in effect immediately.
    static void updateWindow(const HWND handle,
                             const bool triggerFrameChange = true,
                             const bool redraw = true);

    // Change the geometry of a window through Win32 API.
    // The width and height will be scaled automatically according to DPI. So
    // just pass the original value.
    static void setWindowGeometry(const HWND handle, const int x, const int y,
                                  const int width, const int height);

    // Move the window to the center of the desktop.
    static void moveWindowToDesktopCenter(const HWND handle);

    // Update Qt's internal data about the window frame, otherwise Qt will
    // take the size of the window frame into account when anyone is trying to
    // change the geometry of the window. That's not what we want.
    static void updateQtFrame(QWindow *const window, const int titleBarHeight);

#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
    bool nativeEventFilter(const QByteArray &eventType, void *message,
                           qintptr *result) override;
#else
    bool nativeEventFilter(const QByteArray &eventType, void *message,
                           long *result) override;
#endif

private:
    // Do not call these two functions directly, otherwise strange things
    // will happen.
    static void install();
    static void uninstall();

    static void updateQtFrame_internal(const HWND handle);
};