revenge-tweak/Sources/Theme.m

#import "Theme.h"
#import "Utils.h"
#import "Logger.h"
#import <objc/runtime.h>

void swizzleDCDThemeColor(NSDictionary<NSString *, NSArray<NSString *> *> *semanticColors) {
    RevengeLog(@"Swizzling DCDThemeColor");

    Class DCDTheme = NSClassFromString(@"DCDTheme");
    Class dcdThemeTarget = object_getClass(DCDTheme);

    SEL themeIndexSelector = NSSelectorFromString(@"themeIndex");
    Method themeIndexMethod = class_getClassMethod(dcdThemeTarget, themeIndexSelector);
    IMP themeIndexImpl = method_getImplementation(themeIndexMethod);
    int (*themeIndex)(id, SEL) = (int (*)(id, SEL))themeIndexImpl;

    Class DCDThemeColor = NSClassFromString(@"DCDThemeColor");
    Class target = object_getClass(DCDThemeColor);

    unsigned int methodCount;
    Method *methods = class_copyMethodList(target, &methodCount);

    for (unsigned int i = 0; i < methodCount; i++) {
        Method method = methods[i];
        SEL selector = method_getName(method);
        NSString *methodName = NSStringFromSelector(selector);

        NSArray<NSString *> *semanticColor = semanticColors[methodName];
        if (semanticColor) {
            RevengeLog(@"Swizzling %@", methodName);

            IMP originalImpl = method_getImplementation(method);
            UIColor *(*original)(id, SEL) = (UIColor *(*)(id, SEL))originalImpl;

            id block = ^UIColor *(id self) {
                int themeIndexVal = themeIndex(dcdThemeTarget, themeIndexSelector);
                if (semanticColor.count - 1 >= themeIndexVal) {
                    UIColor *semanticUIColor = hexToUIColor(semanticColor[themeIndexVal]);
                    if (semanticUIColor) {
                        return semanticUIColor;
                    }
                }
                return original(target, selector);
            };

            IMP newImpl = imp_implementationWithBlock(block);
            method_setImplementation(method, newImpl);
        }
    }

    free(methods);
}

void swizzleUIColor(NSDictionary<NSString *, NSString *> *rawColors) {
    RevengeLog(@"Swizzling UIColor");

    Class UIColorClass = NSClassFromString(@"UIColor");
    Class target = object_getClass(UIColorClass);

    unsigned int methodCount;
    Method *methods = class_copyMethodList(target, &methodCount);

    for (unsigned int i = 0; i < methodCount; i++) {
        Method method = methods[i];
        SEL selector = method_getName(method);
        NSString *methodName = NSStringFromSelector(selector);

        NSString *rawColor = rawColors[methodName];
        if (rawColor) {
            RevengeLog(@"Swizzling %@", methodName);

            id block = ^UIColor *(id self) {
                return hexToUIColor(rawColor);
            };

            IMP newImpl = imp_implementationWithBlock(block);
            method_setImplementation(method, newImpl);
        }
    }

    free(methods);
}