macdriver: add NSUserDefaults bindings

[tmc]

This is the result of:

1. running macschema pull foundation/nsuserdefaults
2. editing ./gen/cmd/gen.go
3. running go run ./gen/cmd
4. adding core/NSUserDefaults.go
5. adding an example

fixes #115

[programmingkidx]

I tried to do what you did but Macschema doesn't work for me. It always gives me this output:
=> Fetching sub-topics...
=> Waiting for workers to finish...
=> Generating schema...
2023/07/03 22:23:47 schema not supported for

Which version of Macschema are you using?
I am using version 0.2.0.

[progrium]

Don't use the release. It's actively being developed and updated so you have to build from main until things settle for a new release.

[programmingkidx]

@tmc Thank you very much for your help. Admittedly I was a little disappointed. I was making my own implementation of NSUserDefaults. This is how far I was:

package main

/*
#cgo CFLAGS: -x objective-c
#cgo LDFLAGS: -lobjc -framework Foundation

#include <Foundation/Foundation.h>
 
void *NSUserDefaults_standardUserDefaults()
{
	return [NSUserDefaults standardUserDefaults];
}
 
void setInteger_ForKey(void *ud, long value, char *defaultName)
{
	NSUserDefaults *theUD = (NSUserDefaults *)ud;
	NSString *keyStr = [NSString stringWithCString: defaultName];
	[theUD setInteger: value forKey: keyStr];
}
 
long integerForKey(void *ud, char *key)
{
	NSUserDefaults *theUD = (NSUserDefaults *)ud;
	NSString *keyStr = [NSString stringWithCString: key];
	return [theUD integerForKey: keyStr];
}
 
void setObject_ForKey(void *ud, char *cValue, char *cDefaultName)
{
	NSUserDefaults *theUD = (NSUserDefaults *)ud;
	NSString *value = [NSString stringWithCString: cValue];
	NSString *key = [NSString stringWithCString: cDefaultName];
	[theUD setObject: value forKey: key];
}
 
char *objectForKey(void *ud, char *defaultName)
{
	NSUserDefaults *theUD = (NSUserDefaults *)ud;
	NSString *key = [NSString stringWithCString: defaultName];
	NSString *returnStr = [theUD objectForKey: key]; //return value guaranteed to be a NSString
	return (char *)[returnStr cString];
 }
 
char *stringForKey(void *p, char *key)
{
	NSUserDefaults *theUD = (NSUserDefaults *)p;
	NSString *objcKey = [NSString stringWithCString: key];
	NSString *objcString = [theUD stringForKey: objcKey];
	return [objcString cString];
}

*/
import "C"
import "unsafe"
import "encoding/json"
//import "fmt"

type NSUserDefaults struct {
	objcObject unsafe.Pointer
}

func NSUserDefaults_standardUserDefaults() NSUserDefaults {
	p := unsafe.Pointer(C.NSUserDefaults_standardUserDefaults())
	userDefaults := NSUserDefaults{p}
	return userDefaults
}

func (ud *NSUserDefaults) SetInteger_ForKey(value int, defaultName string) {
	defaultNameCStr := C.CString(defaultName)
	cNumber := C.long(value)
	C.setInteger_ForKey(ud.objcObject, cNumber, defaultNameCStr)
}

func (ud NSUserDefaults) IntegerForKey(key string) int {
	p := ud.objcObject
	keyCStr := C.CString(key)
	value := C.integerForKey(p, keyCStr)
	goValue := int(value)
	return goValue
}

func (ud *NSUserDefaults) SetObjectForKey(value interface{}, defaultName string) {
	p := ud.objcObject
	strValue, err := json.Marshal(value) // Converts any Go type into a string for easier conversion to Objective-C
	if err != nil {
		panic(err)
	}
	cValue := C.CString(string(strValue))
	cDefaultName := C.CString(defaultName)
	C.setObject_ForKey(p, cValue, cDefaultName)
}


func (ud NSUserDefaults) ObjectForKey(defaultName string) []byte {
	p := ud.objcObject
	cDefaultName := C.CString(defaultName)
	cValue := C.objectForKey(p, cDefaultName)
	goStrValue := C.GoString(cValue)
	return []byte(goStrValue)
}

func (ud NSUserDefaults) StringForKey(key string) string {
	p := ud.objcObject
	cKey := C.CString(key)
	value := C.stringForKey(p, cKey)
	goValue := C.GoString(value)
	goValue = goValue[1:len(goValue)-1] // remove surrounding double-quotes
	return goValue
}

The main.go file I made for testing:

package main

import "fmt"
import "encoding/json"

func main() {
	// Get the object
	ud := NSUserDefaults_standardUserDefaults()
	
	// Set Value1 to 99
	ud.SetInteger_ForKey(99, "Value1")
	
	// Retrieve the value to see if it was stored correctly
	value1 := ud.IntegerForKey("Value1")
	
	// Run the test
	if value1 == 99 {
		fmt.Println("Test 1 Pass")
	} else {
		fmt.Println("Test 1 Fail")
	}
	
	// Create a Go structure
	type Computer struct {
		Model string
		RamSize int
		CPU string
		Manufacturer string
	}
	
	// Create an instance of Computer
	macbook := Computer{"MacBook Air", 16, "M1", "Apple"}
	
	// Make sure it is working correctly
	fmt.Println("Value going in:", macbook)
	
	// Store the Go object using NSUserDefaults
	ud.SetObjectForKey(macbook, "My Laptop")
	
	// Get the Go object
	var aComputer Computer
	rawBytes := ud.ObjectForKey("My Laptop")
	json.Unmarshal(rawBytes, &aComputer)
	fmt.Println("Value coming out:", aComputer)
	success := aComputer.Model == "MacBook Air" && aComputer.RamSize == 16 &&
	aComputer.CPU == "M1" && aComputer.Manufacturer == "Apple"
	if success == true {
		fmt.Println("Test 2 - Pass")
	} else {
		fmt.Println("Test 2 - Fail")
	}

	// stringForKey test
	value := "One two three"
	key := "numbers"
	ud.SetObjectForKey(value, key)
	strValue := ud.StringForKey(key)
	fmt.Println("Expected:", value, "Received Value:", strValue)
	if strValue == value {
		fmt.Println("Test 3 - Pass")
	} else {
		fmt.Println("Test 3 - Fail")
	}
}