iOS: create our own OS support file

Up until now we just reused the macos.c file for convenience, hard coding a
specific file path that may or may not work on iOS.  Instead get the preferred
path from Qt and for this we need to be able to call into Qt, so this needs to
be a C++ file.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

core/ios.cpp

@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0
+/* implements iOS specific functions */
+#include <stdlib.h>
+#include <dirent.h>
+#include <fnmatch.h>
+#include "dive.h"
+#include "display.h"
+#include "core/qthelper.h"
+#include <CoreFoundation/CoreFoundation.h>
+#if !defined(__IPHONE_5_0)
+#include <CoreServices/CoreServices.h>
+#endif
+#include <mach-o/dyld.h>
+#include <sys/syslimits.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <QStandardPaths>
+
+extern "C" {
+
+const char mac_system_divelist_default_font[] = "Arial";
+const char *system_divelist_default_font = mac_system_divelist_default_font;
+double system_divelist_default_font_size = -1.0;
+
+void subsurface_OS_pref_setup(void)
+{
+	// nothing
+}
+
+bool subsurface_ignore_font(const char *font)
+{
+	// there are no old default fonts that we would want to ignore
+	Q_UNUSED(font);
+	return false;
+}
+
+void subsurface_user_info(struct user_info *user)
+{
+	// We	 use of at least libgit2-0.20
+	Q_UNUSED(user);
+}
+
+static const char *system_default_path_append(const char *append)
+{
+	// Qt appears to find a working path for us - let's just go with that
+	QString path = QStandardPaths::standardLocations(QStandardPaths::DataLocation).first();
+
+	if (append)
+		path += QString("/%1").arg(append);
+
+	return copy_qstring(path);
+}
+
+const char *system_default_directory(void)
+{
+	static const char *path = NULL;
+	if (!path)
+		path = system_default_path_append(NULL);
+	return path;
+}
+
+const char *system_default_filename(void)
+{
+	static const char *filename = "subsurface.xml";
+	static const char *path = NULL;
+	if (!path)
+		path = system_default_path_append(filename);
+	return path;
+}
+
+int enumerate_devices(device_callback_t callback, void *userdata, int dc_type)
+{
+	// we can't read from devices on iOS
+	Q_UNUSED(callback)
+	Q_UNUSED(userdata)
+	Q_UNUSED(dc_type)
+	return -1;
+}
+
+/* NOP wrappers to comform with windows.c */
+int subsurface_rename(const char *path, const char *newpath)
+{
+	return rename(path, newpath);
+}
+
+int subsurface_open(const char *path, int oflags, mode_t mode)
+{
+	return open(path, oflags, mode);
+}
+
+FILE *subsurface_fopen(const char *path, const char *mode)
+{
+	return fopen(path, mode);
+}
+
+void *subsurface_opendir(const char *path)
+{
+	return (void *)opendir(path);
+}
+
+int subsurface_access(const char *path, int mode)
+{
+	return access(path, mode);
+}
+
+int subsurface_stat(const char* path, struct stat* buf)
+{
+	return stat(path, buf);
+}
+
+struct zip *subsurface_zip_open_readonly(const char *path, int flags, int *errorp)
+{
+	return zip_open(path, flags, errorp);
+}
+
+int subsurface_zip_close(struct zip *zip)
+{
+	return zip_close(zip);
+}
+
+/* win32 console */
+void subsurface_console_init(void)
+{
+	/* NOP */
+}
+
+void subsurface_console_exit(void)
+{
+	/* NOP */
+}
+
+bool subsurface_user_is_root()
+{
+	return false;
+}
+}

packaging/ios/Subsurface-mobile/Subsurface-mobile.pro

@@ -37,7 +37,7 @@ SOURCES += ../../../subsurface-mobile-main.cpp \
     ../../../core/windowtitleupdate.cpp \
     ../../../core/file.c \
     ../../../core/subsurfacestartup.c \
-    ../../../core/macos.c \
+    ../../../core/ios.cpp \
     ../../../core/profile.c \
     ../../../core/device.c \
     ../../../core/dive.c \