macOS: Pick up QWizard background from keyboard assistant via NSBundle

As of macOS 10.14 the keyboard assistant background is shipped as part
of the compiled asset catalog of the app, so looking it up via a URL
will fail.

Instead we look it up via NSBundle's dedicated image lookup function,
which handles both cases.

The logic has also been moved to qwizard.cpp, since the additional
plumbing via QPlatformNativeInterface was unnecessary.

The keyboard assistant itself no longer shows the background image
as of macOS 12, so we might consider doing the same, but the design
of the assistant has also changed significantly, so as long as our
QWizard layout looks like the old keyboard assistant we keep the
background as well.

Change-Id: I7d42dd79b285f3518837458864bca6bc353b3b6d
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>
(cherry picked from commit c26c91b2088a05bbe1ed3b529a4b0fc0ea9d3a92)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/plugins/platforms/cocoa/qcocoanativeinterface.h

@@ -31,12 +31,6 @@ public Q_SLOTS:
     void onAppFocusWindowChanged(QWindow *window);
 
 private:
-    /*
-        Function to return the default background pixmap.
-        Needed by QWizard in the Qt widget module.
-    */
-    Q_INVOKABLE QPixmap defaultBackgroundPixmapForQWizard();
-
     Q_INVOKABLE void clearCurrentThreadCocoaEventDispatcherInterruptFlag();
 
     static void registerDraggedTypes(const QStringList &types);

src/plugins/platforms/cocoa/qcocoanativeinterface.mm

@@ -75,35 +75,6 @@ QPlatformNativeInterface::NativeResourceForIntegrationFunction QCocoaNativeInter
     return nullptr;
 }
 
-QPixmap QCocoaNativeInterface::defaultBackgroundPixmapForQWizard()
-{
-    // Note: starting with macOS 10.14, the KeyboardSetupAssistant app bundle no
-    // longer contains the "Background.png" image. This function then returns a
-    // null pixmap.
-    const int ExpectedImageWidth = 242;
-    const int ExpectedImageHeight = 414;
-    QCFType<CFArrayRef> urls = LSCopyApplicationURLsForBundleIdentifier(
-        CFSTR("com.apple.KeyboardSetupAssistant"), nullptr);
-    if (urls && CFArrayGetCount(urls) > 0) {
-        CFURLRef url = (CFURLRef)CFArrayGetValueAtIndex(urls, 0);
-        QCFType<CFBundleRef> bundle = CFBundleCreate(kCFAllocatorDefault, url);
-        if (bundle) {
-            url = CFBundleCopyResourceURL(bundle, CFSTR("Background"), CFSTR("png"), nullptr);
-            if (url) {
-                QCFType<CGImageSourceRef> imageSource = CGImageSourceCreateWithURL(url, nullptr);
-                QCFType<CGImageRef> image = CGImageSourceCreateImageAtIndex(imageSource, 0, nullptr);
-                if (image) {
-                    int width = CGImageGetWidth(image);
-                    int height = CGImageGetHeight(image);
-                    if (width == ExpectedImageWidth && height == ExpectedImageHeight)
-                        return QPixmap::fromImage(qt_mac_toQImage(image));
-                }
-            }
-        }
-    }
-    return QPixmap();
-}
-
 void QCocoaNativeInterface::clearCurrentThreadCocoaEventDispatcherInterruptFlag()
 {
     QCocoaEventDispatcher::clearCurrentThreadCocoaEventDispatcherInterruptFlag();

src/widgets/CMakeLists.txt

@@ -684,15 +684,25 @@ qt_internal_extend_target(Widgets CONDITION QT_FEATURE_progressdialog
         dialogs/qprogressdialog.cpp dialogs/qprogressdialog.h
 )
 
-qt_internal_extend_target(Widgets CONDITION QT_FEATURE_wizard
+if(QT_FEATURE_wizard)
+    qt_internal_extend_target(Widgets CONDITION
         SOURCES
             dialogs/qwizard.cpp dialogs/qwizard.h
     )
 
-qt_internal_extend_target(Widgets CONDITION QT_FEATURE_wizard AND WIN32
+    if(APPLE)
+        set_source_files_properties(dialogs/qwizard.cpp
+            PROPERTIES
+                COMPILE_FLAGS "-x objective-c++"
+                SKIP_PRECOMPILE_HEADERS ON
+        )
+    endif()
+
+    qt_internal_extend_target(Widgets CONDITION WIN32
         SOURCES
             dialogs/qwizard_win.cpp dialogs/qwizard_win_p.h
     )
+endif()
 
 qt_internal_extend_target(Widgets CONDITION QT_FEATURE_accessibility
     SOURCES

src/widgets/dialogs/qwizard.cpp

@@ -29,9 +29,8 @@
 #include "qstyleoption.h"
 #include "qvarlengtharray.h"
 #if defined(Q_OS_MACOS)
-#include <QtCore/QMetaMethod>
-#include <QtGui/QGuiApplication>
-#include <qpa/qplatformnativeinterface.h>
+#include <AppKit/AppKit.h>
+#include <QtGui/private/qcoregraphics_p.h>
 #elif QT_CONFIG(style_windowsvista)
 #include "qwizard_win_p.h"
 #include "qtimer.h"
@@ -1723,23 +1722,19 @@ void QWizardPrivate::setStyle(QStyle *style)
 }
 
 #ifdef Q_OS_MACOS
-
 QPixmap QWizardPrivate::findDefaultBackgroundPixmap()
 {
-    QGuiApplication *app = qobject_cast<QGuiApplication *>(QCoreApplication::instance());
-    if (!app)
-        return QPixmap();
-    QPlatformNativeInterface *platformNativeInterface = app->platformNativeInterface();
-    int at = platformNativeInterface->metaObject()->indexOfMethod("defaultBackgroundPixmapForQWizard()");
-    if (at == -1)
-        return QPixmap();
-    QMetaMethod defaultBackgroundPixmapForQWizard = platformNativeInterface->metaObject()->method(at);
-    QPixmap result;
-    if (!defaultBackgroundPixmapForQWizard.invoke(platformNativeInterface, Q_RETURN_ARG(QPixmap, result)))
-        return QPixmap();
-    return result;
-}
+    auto *keyboardAssistantURL = [NSWorkspace.sharedWorkspace
+        URLForApplicationWithBundleIdentifier:@"com.apple.KeyboardSetupAssistant"];
+    auto *keyboardAssistantBundle = [NSBundle bundleWithURL:keyboardAssistantURL];
+    auto *assistantBackground = [keyboardAssistantBundle imageForResource:@"Background"];
+    auto size = QSizeF::fromCGSize(assistantBackground.size);
+    static const QSizeF expectedSize(242, 414);
+    if (size == expectedSize)
+        return qt_mac_toQPixmap(assistantBackground, size);
 
+    return QPixmap();
+}
 #endif
 
 #if QT_CONFIG(style_windowsvista)
@@ -2845,7 +2840,7 @@ void QWizard::setPixmap(WizardPixmap which, const QPixmap &pixmap)
     Returns the pixmap set for role \a which.
 
     By default, the only pixmap that is set is the BackgroundPixmap on
-    \macos version 10.13 and earlier.
+    \macos.
 
     \sa QWizardPage::pixmap(), {Elements of a Wizard Page}
 */

tests/auto/widgets/dialogs/qwizard/tst_qwizard.cpp

@@ -398,7 +398,7 @@ void tst_QWizard::setPixmap()
     QVERIFY(wizard.pixmap(QWizard::BannerPixmap).isNull());
     QVERIFY(wizard.pixmap(QWizard::LogoPixmap).isNull());
     QVERIFY(wizard.pixmap(QWizard::WatermarkPixmap).isNull());
-    if (QOperatingSystemVersion::current() <= QOperatingSystemVersion::MacOSHighSierra)
+    if (QOperatingSystemVersion::currentType() == QOperatingSystemVersion::MacOS)
         QVERIFY(!wizard.pixmap(QWizard::BackgroundPixmap).isNull());
     else
         QVERIFY(wizard.pixmap(QWizard::BackgroundPixmap).isNull());
@@ -406,7 +406,7 @@ void tst_QWizard::setPixmap()
     QVERIFY(page->pixmap(QWizard::BannerPixmap).isNull());
     QVERIFY(page->pixmap(QWizard::LogoPixmap).isNull());
     QVERIFY(page->pixmap(QWizard::WatermarkPixmap).isNull());
-    if (QOperatingSystemVersion::current() <= QOperatingSystemVersion::MacOSHighSierra)
+    if (QOperatingSystemVersion::currentType() == QOperatingSystemVersion::MacOS)
         QVERIFY(!wizard.pixmap(QWizard::BackgroundPixmap).isNull());
     else
         QVERIFY(page->pixmap(QWizard::BackgroundPixmap).isNull());