Long live QPlatformKeyMapper!

The QKeyMapper class never got a platform integration companion.

As we might be adding more functionality here in the future, let's
fix that now, instead of adding more hooks directly to the platform
integration class.

The QKeyMapper will soon update its possibleKeys signature to
return QKeyCombination, but for now transform the result.

Change-Id: I88ef498180b2a8a7937a74627b7eb6b5156e872a
Reviewed-by: Liang Qi <[email protected]>

9 files changed, 116 insertions, 10 deletions

diff --git a/src/gui/CMakeLists.txt b/src/gui/CMakeLists.txt
index 815dcb1398a..8934b025ed4 100644
--- a/src/gui/CMakeLists.txt
+++ b/src/gui/CMakeLists.txt
@@ -114,6 +114,7 @@ qt_internal_add_module(Gui
         kernel/qplatformintegration.cpp kernel/qplatformintegration.h
         kernel/qplatformintegrationfactory.cpp kernel/qplatformintegrationfactory_p.h
         kernel/qplatformintegrationplugin.cpp kernel/qplatformintegrationplugin.h
+        kernel/qplatformkeymapper.cpp kernel/qplatformkeymapper.h
         kernel/qplatformmenu.cpp kernel/qplatformmenu.h kernel/qplatformmenu_p.h
         kernel/qplatformnativeinterface.cpp kernel/qplatformnativeinterface.h
         kernel/qplatformoffscreensurface.cpp kernel/qplatformoffscreensurface.h
diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index 5d98548ada9..3e9e966cf06 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -17,6 +17,7 @@
 #include <qpa/qplatformnativeinterface.h>
 #include <qpa/qplatformtheme.h>
 #include <qpa/qplatformintegration.h>
+#include <qpa/qplatformkeymapper.h>
 
 #include <QtCore/QAbstractEventDispatcher>
 #include <QtCore/QFileInfo>
@@ -1847,7 +1848,7 @@ Qt::KeyboardModifiers QGuiApplication::queryKeyboardModifiers()
 {
     CHECK_QAPP_INSTANCE(Qt::KeyboardModifiers{})
     QPlatformIntegration *pi = QGuiApplicationPrivate::platformIntegration();
-    return pi->queryKeyboardModifiers();
+    return pi->keyMapper()->queryKeyboardModifiers();
 }
 
 /*!
diff --git a/src/gui/kernel/qkeymapper.cpp b/src/gui/kernel/qkeymapper.cpp
index ff781ec43ba..bd7dbd90e9d 100644
--- a/src/gui/kernel/qkeymapper.cpp
+++ b/src/gui/kernel/qkeymapper.cpp
@@ -9,6 +9,7 @@
 
 #include <private/qguiapplication_p.h>
 #include <qpa/qplatformintegration.h>
+#include <qpa/qplatformkeymapper.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -36,14 +37,21 @@ QKeyMapper::~QKeyMapper()
 
 QList<int> QKeyMapper::possibleKeys(const QKeyEvent *e)
 {
-    QList<int> result = QGuiApplicationPrivate::platformIntegration()->possibleKeys(e);
-    if (!result.isEmpty())
-        return result;
-
-    if (e->key() && (e->key() != Qt::Key_unknown))
-        result << e->keyCombination().toCombined();
-    else if (!e->text().isEmpty())
-        result << int(e->text().at(0).unicode() + (int)e->modifiers());
+    QList<int> result;
+
+    const auto *platformIntegration = QGuiApplicationPrivate::platformIntegration();
+    const auto *platformKeyMapper = platformIntegration->keyMapper();
+    const auto keyCombinations = platformKeyMapper->possibleKeyCombinations(e);
+    for (auto keyCombination : keyCombinations)
+        result << keyCombination.toCombined();
+
+    if (result.isEmpty()) {
+        if (e->key() && (e->key() != Qt::Key_unknown))
+            result << e->keyCombination().toCombined();
+        else if (!e->text().isEmpty())
+            result << int(e->text().at(0).unicode() + (int)e->modifiers());
+    }
+
     return result;
 }
 
diff --git a/src/gui/kernel/qplatformintegration.cpp b/src/gui/kernel/qplatformintegration.cpp
index b7117b121dd..3b20d2e7e47 100644
--- a/src/gui/kernel/qplatformintegration.cpp
+++ b/src/gui/kernel/qplatformintegration.cpp
@@ -6,6 +6,7 @@
 #include <qpa/qplatformfontdatabase.h>
 #include <qpa/qplatformclipboard.h>
 #include <qpa/qplatformaccessibility.h>
+#include <qpa/qplatformkeymapper.h>
 #include <qpa/qplatformtheme.h>
 #include <QtGui/private/qguiapplication_p.h>
 #include <QtGui/private/qpixmap_raster_p.h>
@@ -342,6 +343,21 @@ QPlatformInputContext *QPlatformIntegration::inputContext() const
     return nullptr;
 }
 
+/*!
+    Accessor for the platform integration's key mapper.
+
+    Default implementation returns a default QPlatformKeyMapper.
+
+    \sa QPlatformKeyMapper
+*/
+QPlatformKeyMapper *QPlatformIntegration::keyMapper() const
+{
+    static QPlatformKeyMapper *keyMapper = nullptr;
+    if (!keyMapper)
+        keyMapper = new QPlatformKeyMapper;
+    return keyMapper;
+}
+
 #if QT_CONFIG(accessibility)
 
 /*!
diff --git a/src/gui/kernel/qplatformintegration.h b/src/gui/kernel/qplatformintegration.h
index 393845012ac..71bf23a55c9 100644
--- a/src/gui/kernel/qplatformintegration.h
+++ b/src/gui/kernel/qplatformintegration.h
@@ -33,6 +33,7 @@ class QPlatformOpenGLContext;
 class QGuiGLFormat;
 class QAbstractEventDispatcher;
 class QPlatformInputContext;
+class QPlatformKeyMapper;
 class QPlatformAccessibility;
 class QPlatformTheme;
 class QPlatformDialogHelper;
@@ -171,8 +172,12 @@ public:
     virtual QVariant styleHint(StyleHint hint) const;
     virtual Qt::WindowState defaultWindowState(Qt::WindowFlags) const;
 
+protected:
     virtual Qt::KeyboardModifiers queryKeyboardModifiers() const;
     virtual QList<int> possibleKeys(const QKeyEvent *) const;
+    friend class QPlatformKeyMapper;
+public:
+    virtual QPlatformKeyMapper *keyMapper() const;
 
     virtual QStringList themeNames() const;
     virtual QPlatformTheme *createPlatformTheme(const QString &name) const;
diff --git a/src/gui/kernel/qplatformkeymapper.cpp b/src/gui/kernel/qplatformkeymapper.cpp
new file mode 100644
index 00000000000..f54e4ff3794
--- /dev/null
+++ b/src/gui/kernel/qplatformkeymapper.cpp
@@ -0,0 +1,38 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#include "qplatformkeymapper.h"
+
+#include <private/qguiapplication_p.h>
+#include <qpa/qplatformintegration.h>
+
+QT_BEGIN_NAMESPACE
+
+Q_LOGGING_CATEGORY(lcQpaKeyMapper, "qt.qpa.keymapper")
+
+QPlatformKeyMapper::~QPlatformKeyMapper()
+{
+}
+
+/*
+    Should return a list of possible key combinations for the given key event.
+
+    For example, given a US English keyboard layout, the key event Shift+5
+    can represent both a "Shift+5" key combination, as well as just "%".
+*/
+QList<QKeyCombination> QPlatformKeyMapper::possibleKeyCombinations(const QKeyEvent *event) const
+{
+    auto *platformIntegration = QGuiApplicationPrivate::platformIntegration();
+    QList<int> possibleKeys = platformIntegration->possibleKeys(event);
+    QList<QKeyCombination> combinations;
+    for (int key : possibleKeys)
+        combinations << QKeyCombination::fromCombined(key);
+    return combinations;
+}
+
+Qt::KeyboardModifiers QPlatformKeyMapper::queryKeyboardModifiers() const
+{
+    return QGuiApplicationPrivate::platformIntegration()->queryKeyboardModifiers();
+}
+
+QT_END_NAMESPACE
diff --git a/src/gui/kernel/qplatformkeymapper.h b/src/gui/kernel/qplatformkeymapper.h
new file mode 100644
index 00000000000..fb5b0cdb8bd
--- /dev/null
+++ b/src/gui/kernel/qplatformkeymapper.h
@@ -0,0 +1,36 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#ifndef QPLATFORMKEYMAPPER_P
+#define QPLATFORMKEYMAPPER_P
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is part of the QPA API and is not meant to be used
+// in applications. Usage of this API may make your code
+// source and binary incompatible with future versions of Qt.
+//
+
+#include <QtGui/qtguiglobal.h>
+#include <QtCore/qloggingcategory.h>
+
+QT_BEGIN_NAMESPACE
+
+Q_DECLARE_EXPORTED_LOGGING_CATEGORY(lcQpaKeyMapper, Q_GUI_EXPORT)
+
+class QKeyEvent;
+
+class Q_GUI_EXPORT QPlatformKeyMapper
+{
+public:
+    virtual ~QPlatformKeyMapper();
+
+    virtual QList<QKeyCombination> possibleKeyCombinations(const QKeyEvent *event) const;
+    virtual Qt::KeyboardModifiers queryKeyboardModifiers() const;
+};
+
+QT_END_NAMESPACE
+
+#endif // QPLATFORMKEYMAPPER_P
diff --git a/src/gui/platform/darwin/qapplekeymapper.mm b/src/gui/platform/darwin/qapplekeymapper.mm
index f7dbc1990d0..12381041864 100644
--- a/src/gui/platform/darwin/qapplekeymapper.mm
+++ b/src/gui/platform/darwin/qapplekeymapper.mm
@@ -18,7 +18,6 @@
 
 QT_BEGIN_NAMESPACE
 
-Q_LOGGING_CATEGORY(lcQpaKeyMapper, "qt.qpa.keymapper");
 Q_LOGGING_CATEGORY(lcQpaKeyMapperKeys, "qt.qpa.keymapper.keys");
 
 static Qt::KeyboardModifiers swapModifiersIfNeeded(const Qt::KeyboardModifiers modifiers)
diff --git a/src/gui/platform/darwin/qapplekeymapper_p.h b/src/gui/platform/darwin/qapplekeymapper_p.h
index 34557c8ede8..0f096e95378 100644
--- a/src/gui/platform/darwin/qapplekeymapper_p.h
+++ b/src/gui/platform/darwin/qapplekeymapper_p.h
@@ -19,6 +19,8 @@
 #include <Carbon/Carbon.h>
 #endif
 
+#include <qpa/qplatformkeymapper.h>
+
 #include <QtCore/QList>
 #include <QtCore/QHash>
 #include <QtGui/QKeyEvent>