WebView 포커스(Focus) 이동시 키보드 노출 안되는 현상 수정

# UIWebView
웹 콘텐츠가 프로그래밍 방식으로 키보드를 표시할 수 있는지 여부를 나타내는 값, 기본값은 YES이다.
NO하면 포커스 이벤트로 인해 키보드가 자동으로 표시된다.

webView.keyboardDisplayRequiresUserAction = NO;

# WKWebView

- (void)allowDisplayingKeyboardWithoutUserAction
{
    Class class = NSClassFromString(@"WKContentView");
    NSOperatingSystemVersion iOS_11_3_0 = (NSOperatingSystemVersion){11, 3, 0};
    NSOperatingSystemVersion iOS_12_2_0 = (NSOperatingSystemVersion){12, 2, 0};
    NSOperatingSystemVersion iOS_13_0_0 = (NSOperatingSystemVersion){13, 0, 0};
    
    if ([[NSProcessInfo processInfo] isOperatingSystemAtLeastVersion: iOS_13_0_0]) {
        SEL selector = sel_getUid("_elementDidFocus:userIsInteracting:blurPreviousNode:activityStateChanges:userObject:");
        Method method = class_getInstanceMethod(class, selector);
        IMP original = method_getImplementation(method);
        IMP override = imp_implementationWithBlock(^void(id me, void* arg0, BOOL arg1, BOOL arg2, BOOL arg3, id arg4) {
        ((void (*)(id, SEL, void*, BOOL, BOOL, BOOL, id))original)(me, selector, arg0, TRUE, arg2, arg3, arg4);
        });
        method_setImplementation(method, override);
    }
    else if ([[NSProcessInfo processInfo] isOperatingSystemAtLeastVersion: iOS_12_2_0]) {
        SEL selector = sel_getUid("_elementDidFocus:userIsInteracting:blurPreviousNode:changingActivityState:userObject:");
        Method method = class_getInstanceMethod(class, selector);
        IMP original = method_getImplementation(method);
        IMP override = imp_implementationWithBlock(^void(id me, void* arg0, BOOL arg1, BOOL arg2, BOOL arg3, id arg4) {
        ((void (*)(id, SEL, void*, BOOL, BOOL, BOOL, id))original)(me, selector, arg0, TRUE, arg2, arg3, arg4);
        });
        method_setImplementation(method, override);
    }
    else if ([[NSProcessInfo processInfo] isOperatingSystemAtLeastVersion: iOS_11_3_0]) {
        SEL selector = sel_getUid("_startAssistingNode:userIsInteracting:blurPreviousNode:changingActivityState:userObject:");
        Method method = class_getInstanceMethod(class, selector);
        IMP original = method_getImplementation(method);
        IMP override = imp_implementationWithBlock(^void(id me, void* arg0, BOOL arg1, BOOL arg2, BOOL arg3, id arg4) {
            ((void (*)(id, SEL, void*, BOOL, BOOL, BOOL, id))original)(me, selector, arg0, TRUE, arg2, arg3, arg4);
        });
        method_setImplementation(method, override);
    }
    else {
        SEL selector = sel_getUid("_startAssistingNode:userIsInteracting:blurPreviousNode:userObject:");
        Method method = class_getInstanceMethod(class, selector);
        IMP original = method_getImplementation(method);
        IMP override = imp_implementationWithBlock(^void(id me, void* arg0, BOOL arg1, BOOL arg2, id arg3) {
            ((void (*)(id, SEL, void*, BOOL, BOOL, id))original)(me, selector, arg0, TRUE, arg2, arg3);
        });
        method_setImplementation(method, override);
    }
}