[qt] refactor: qt_common lib (#94)

This is part of a series of PRs made in preparation for the QML rewrite. this PR specifically moves a bunch of utility functions from main.cpp into qt_common, with the biggest benefit being that QML can reuse the exact same code through ctx passthrough.

Also, QtCommon::Frontend is an abstraction layer over several previously Widgets-specific stuff like QMessageBox that gets used everywhere. The idea is that once QML is implemented, these functions can have a Quick version implemented for systems that don't work well with Widgets (sun) or for those on Plasma 6+ (reduces memory usage w/o Widgets linkage) although Quick from C++ is actually anal, but whatever.

Other than that this should also just kinda reduce the size of main.cpp which is a 6000-line behemoth rn, and clangd straight up gives up with it for me (likely caused by the massive amount of headers, which this DOES reduce).

In the future, I probably want to create a common strings lookup table that both Qt and QML can reference--though I'm not sure how much linguist likes that--which should give us a way to keep language consistent (use frozen-map).

TODO: Docs for Qt stuff

Co-authored-by: MaranBr <maranbr@outlook.com>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/94
Reviewed-by: MaranBr <maranbr@eden-emu.dev>
Reviewed-by: Shinmegumi <shinmegumi@eden-emu.dev>

src/qt_common/qt_frontend_util.h

@@ -0,0 +1,148 @@
+// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef QT_FRONTEND_UTIL_H
+#define QT_FRONTEND_UTIL_H
+
+#include <QGuiApplication>
+#include "qt_common/qt_common.h"
+
+#ifdef YUZU_QT_WIDGETS
+#include <QFileDialog>
+#include <QWidget>
+#include <QMessageBox>
+#endif
+
+/**
+ * manages common functionality e.g. message boxes and such for Qt/QML
+ */
+namespace QtCommon::Frontend {
+
+Q_NAMESPACE
+
+#ifdef YUZU_QT_WIDGETS
+using Options = QFileDialog::Options;
+using Option = QFileDialog::Option;
+
+using StandardButton = QMessageBox::StandardButton;
+using StandardButtons = QMessageBox::StandardButtons;
+
+using Icon = QMessageBox::Icon;
+#else
+enum Option {
+    ShowDirsOnly = 0x00000001,
+    DontResolveSymlinks = 0x00000002,
+    DontConfirmOverwrite = 0x00000004,
+    DontUseNativeDialog = 0x00000008,
+    ReadOnly = 0x00000010,
+    HideNameFilterDetails = 0x00000020,
+    DontUseCustomDirectoryIcons = 0x00000040
+};
+Q_ENUM_NS(Option)
+Q_DECLARE_FLAGS(Options, Option)
+Q_FLAG_NS(Options)
+
+enum StandardButton {
+    // keep this in sync with QDialogButtonBox::StandardButton and QPlatformDialogHelper::StandardButton
+    NoButton           = 0x00000000,
+    Ok                 = 0x00000400,
+    Save               = 0x00000800,
+    SaveAll            = 0x00001000,
+    Open               = 0x00002000,
+    Yes                = 0x00004000,
+    YesToAll           = 0x00008000,
+    No                 = 0x00010000,
+    NoToAll            = 0x00020000,
+    Abort              = 0x00040000,
+    Retry              = 0x00080000,
+    Ignore             = 0x00100000,
+    Close              = 0x00200000,
+    Cancel             = 0x00400000,
+    Discard            = 0x00800000,
+    Help               = 0x01000000,
+    Apply              = 0x02000000,
+    Reset              = 0x04000000,
+    RestoreDefaults    = 0x08000000,
+
+    FirstButton        = Ok,                // internal
+    LastButton         = RestoreDefaults,   // internal
+
+    YesAll             = YesToAll,          // obsolete
+    NoAll              = NoToAll,           // obsolete
+
+    Default            = 0x00000100,        // obsolete
+    Escape             = 0x00000200,        // obsolete
+    FlagMask           = 0x00000300,        // obsolete
+    ButtonMask         = ~FlagMask          // obsolete
+};
+Q_ENUM_NS(StandardButton)
+
+#if QT_VERSION < QT_VERSION_CHECK(7, 0, 0)
+typedef StandardButton Button;
+#endif
+Q_DECLARE_FLAGS(StandardButtons, StandardButton)
+Q_FLAG_NS(StandardButtons)
+
+enum Icon {
+    // keep this in sync with QMessageDialogOptions::StandardIcon
+    NoIcon = 0,
+    Information = 1,
+    Warning = 2,
+    Critical = 3,
+    Question = 4
+};
+Q_ENUM_NS(Icon)
+
+#endif
+
+// TODO(crueter) widgets-less impl, choices et al.
+StandardButton ShowMessage(Icon icon,
+                                        const QString &title,
+                                        const QString &text,
+                                        StandardButtons buttons = StandardButton::NoButton,
+                                        QObject *parent = nullptr);
+
+#define UTIL_OVERRIDES(level) \
+    inline StandardButton level(QObject *parent, \
+                                             const QString &title, \
+                                             const QString &text, \
+                                             StandardButtons buttons = StandardButton::Ok) \
+    { \
+        return ShowMessage(Icon::level, title, text, buttons, parent); \
+    } \
+    inline StandardButton level(QObject *parent, \
+                                             const char *title, \
+                                             const char *text, \
+                                             StandardButtons buttons \
+                                             = StandardButton::Ok) \
+    { \
+        return ShowMessage(Icon::level, tr(title), tr(text), buttons, parent); \
+    } \
+    inline StandardButton level(const char *title, \
+                                             const char *text, \
+                                             StandardButtons buttons \
+                                             = StandardButton::Ok) \
+    { \
+        return ShowMessage(Icon::level, tr(title), tr(text), buttons, rootObject); \
+    } \
+    inline StandardButton level(const QString title, \
+                                             const QString &text, \
+                                             StandardButtons buttons \
+                                             = StandardButton::Ok) \
+    { \
+        return ShowMessage(Icon::level, title, text, buttons, rootObject); \
+    }
+
+UTIL_OVERRIDES(Information)
+UTIL_OVERRIDES(Warning)
+UTIL_OVERRIDES(Critical)
+UTIL_OVERRIDES(Question)
+
+const QString GetOpenFileName(const QString &title,
+                              const QString &dir,
+                              const QString &filter,
+                              QString *selectedFilter = nullptr,
+                              Options options = Options());
+
+} // namespace QtCommon::Frontend
+#endif // QT_FRONTEND_UTIL_H