Cocoa: Translate the buttons used for the native font and color dialogs

Use the QPlatformDialogHelper standard buttons to get the translated
button text as then this will already have been translated for those
loading a translation.

Pick-to: 5.15 5.12
Fixes: QTBUG-85725
Change-Id: Ia42d93aeb6e1b5c0528564a6c960a35f6710c8eb
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

src/plugins/platforms/cocoa/qcocoahelpers.h

@@ -55,6 +55,7 @@
 #include <QtCore/qloggingcategory.h>
 #include <QtGui/qpalette.h>
 #include <QtGui/qscreen.h>
+#include <qpa/qplatformdialoghelper.h>
 
 #include <objc/runtime.h>
 #include <objc/message.h>
@@ -211,7 +212,7 @@ QT_END_NAMESPACE
 - (instancetype)initWithPanelDelegate:(id<QNSPanelDelegate>)panelDelegate;
 - (void)dealloc;
 
-- (NSButton *)createButtonWithTitle:(const char *)title;
+- (NSButton *)createButtonWithTitle:(QPlatformDialogHelper::StandardButton)type;
 - (void)layout;
 
 @end

src/plugins/platforms/cocoa/qcocoahelpers.mm

@@ -392,11 +392,10 @@ QT_END_NAMESPACE
 {
     if ((self = [super initWithFrame:NSZeroRect])) {
         // create OK and Cancel buttons and add these as subviews
-        _okButton = [self createButtonWithTitle:"&OK"];
+        _okButton = [self createButtonWithTitle:QPlatformDialogHelper::Ok];
         _okButton.action = @selector(onOkClicked);
         _okButton.target = panelDelegate;
-
-        _cancelButton = [self createButtonWithTitle:"Cancel"];
+        _cancelButton = [self createButtonWithTitle:QPlatformDialogHelper::Cancel];
         _cancelButton.action = @selector(onCancelClicked);
         _cancelButton.target = panelDelegate;
 
@@ -420,12 +419,13 @@ QT_END_NAMESPACE
     [super dealloc];
 }
 
-- (NSButton *)createButtonWithTitle:(const char *)title
+- (NSButton *)createButtonWithTitle:(QPlatformDialogHelper::StandardButton)type
 {
     NSButton *button = [[NSButton alloc] initWithFrame:NSZeroRect];
     button.buttonType = NSButtonTypeMomentaryLight;
     button.bezelStyle = NSBezelStyleRounded;
-    const QString &cleanTitle = QPlatformTheme::removeMnemonics(QCoreApplication::translate("QDialogButtonBox", title));
+    const QString &cleanTitle =
+         QPlatformTheme::removeMnemonics(QGuiApplicationPrivate::platformTheme()->standardButtonText(type));
     // FIXME: Not obvious, from Cocoa's documentation, that QString::toNSString() makes a deep copy
     button.title = (NSString *)cleanTitle.toCFString();
     ((NSButtonCell *)button.cell).font =