NMUniversalAccessHelper.m

//
//  DCUniversalAccessHelper.m
//  dc
//
//  Created by Work on 22/10/2010.
//  Copyright 2010 Nicholas Moore. All rights reserved.
//

#import "NMUniversalAccessHelper.h"
#import "NMAppUtils.h"

// for dlsym & weak linking
#import <dlfcn.h>
static Boolean (*_weak_AXIsProcessTrustedWithOptions)(CFDictionaryRef);
static CFStringRef *_weak_kAXTrustedCheckOptionPrompt;

static NMUniversalAccessHelper *_sharedInstance;

NSString *NMUniversalAccessStateChangedNotification=@"NMUniversalAccessStateChangedNotification";

@implementation NMUniversalAccessHelper

+ (NMUniversalAccessHelper *)sharedInstance
{
	if (!_sharedInstance) {
		_sharedInstance=[[NMUniversalAccessHelper alloc] init];
        _weak_AXIsProcessTrustedWithOptions=dlsym(RTLD_DEFAULT, "AXIsProcessTrustedWithOptions");
        _weak_kAXTrustedCheckOptionPrompt=dlsym(RTLD_DEFAULT, "kAXTrustedCheckOptionPrompt");
	}
	return _sharedInstance;
}

// if available, use the new Check with prompt method
+ (BOOL)checkAxTrustedWithPrompt:(BOOL)prompt
{
    if (_weak_AXIsProcessTrustedWithOptions!=0&&_weak_kAXTrustedCheckOptionPrompt!=0) {
        return (_weak_AXIsProcessTrustedWithOptions)((__bridge CFDictionaryRef)@{(__bridge NSString*)(*_weak_kAXTrustedCheckOptionPrompt): @(prompt)});
    }
    else {
        return AXIsProcessTrusted();
    }
}

- (id)init
{
    self=[super init];
    if (self) {
        [self refreshState];        
    }

	return self;
}

- (BOOL)isAxEnabled
{
	return AXAPIEnabled()||[[self class] checkAxTrustedWithPrompt:NO];
}

- (void)refreshState
{
	BOOL is=[self isAxEnabled];
	if (is!=axWasEnabled) {
		[self willChangeValueForKey:@"axEnabled"];
		[self didChangeValueForKey:@"axEnabled"];
        [[NSNotificationCenter defaultCenter] postNotificationName:NMUniversalAccessStateChangedNotification object:self userInfo:@{@"axEnabled": @(is)}];
	}
	axWasEnabled=is;
}

+ (void)openUniversalAccessPane
{
    [[NSWorkspace sharedWorkspace] openFile:@"/System/Library/PreferencePanes/UniversalAccessPref.prefPane"];
}

+ (BOOL)enableUniversalAccess
{
    if (NMOSVersionCheckMountainLionOrBelow()) {
        BOOL good=NO;
        NSString *s = [NSString stringWithFormat:
                       @"tell application \"System Events\"\n"
                       @"\tif UI elements enabled is false then\n"
                       @"\t\tactivate\n"
                       @"\t\tset UI elements enabled to true\n"
                       @"\tend\n"
                       @"\treturn UI elements enabled\n"
                       @"end tell"];
        NSAppleScript *scriptObj = [[NSAppleScript alloc] initWithSource:s];
        if (scriptObj) {
            NSDictionary *error = nil;
            NSAppleEventDescriptor *desc = [scriptObj executeAndReturnError:&error];
            if(error) {
                //NMLogFine(@"%@", error);
            }
            else if(desc) {
                good = [desc booleanValue];
            }
        }
        return good;
    }
    else {
        return [self checkAxTrustedWithPrompt:YES];
    }
}



@end