FLEX/Classes/ObjectExplorers/Controllers/FLEXViewExplorerViewController.m

//
//  FLEXViewExplorerViewController.m
//  Flipboard
//
//  Created by Ryan Olson on 6/11/14.
//  Copyright (c) 2014 Flipboard. All rights reserved.
//

#import "FLEXViewExplorerViewController.h"
#import "FLEXRuntimeUtility.h"
#import "FLEXUtility.h"
#import "FLEXObjectExplorerFactory.h"
#import "FLEXImagePreviewViewController.h"
#import "FLEXPropertyEditorViewController.h"

typedef NS_ENUM(NSUInteger, FLEXViewExplorerRow) {
    FLEXViewExplorerRowViewController,
    FLEXViewExplorerRowPreview,
    FLEXViewExplorerRowViewControllerForAncestor
};

@interface FLEXViewExplorerViewController ()

// Don't clash with UIViewController's view property
@property (nonatomic, readonly) UIView *viewToExplore;

@end

@implementation FLEXViewExplorerViewController

- (UIView *)viewToExplore
{
    return [self.object isKindOfClass:[UIView class]] ? self.object : nil;
}


#pragma mark - Superclass Overrides

- (NSString *)customSectionTitle
{
    return @"Shortcuts";
}

- (NSArray *)customSectionRowCookies
{
    NSMutableArray *rowCookies = [NSMutableArray array];
    
    if ([FLEXUtility viewControllerForView:self.viewToExplore]) {
        [rowCookies addObject:@(FLEXViewExplorerRowViewController)];
    }else{
        [rowCookies addObject:@(FLEXViewExplorerRowViewControllerForAncestor)];
    }
    
    [rowCookies addObject:@(FLEXViewExplorerRowPreview)];
    [rowCookies addObjectsFromArray:[super customSectionRowCookies]];
    
    return rowCookies;
}

- (NSArray<NSString *> *)shortcutPropertyNames
{
    NSArray *propertyNames = @[@"frame", @"bounds", @"center", @"transform",
                               @"backgroundColor", @"alpha", @"opaque", @"hidden",
                               @"clipsToBounds", @"userInteractionEnabled", @"layer"];
    
    if ([self.viewToExplore isKindOfClass:[UILabel class]]) {
        propertyNames = [@[@"text", @"font", @"textColor"] arrayByAddingObjectsFromArray:propertyNames];
    }
    
    return propertyNames;
}

- (NSString *)customSectionTitleForRowCookie:(id)rowCookie
{
    NSString *title = nil;
    
    if ([rowCookie isKindOfClass:[NSNumber class]]) {
        FLEXViewExplorerRow row = [rowCookie unsignedIntegerValue];
        switch (row) {
            case FLEXViewExplorerRowViewController:
                title = @"View Controller";
                break;
                
            case FLEXViewExplorerRowPreview:
                title = @"Preview Image";
                break;
            
            case FLEXViewExplorerRowViewControllerForAncestor:
                title = @"View Controller For Ancestor";
                break;
        }
    } else if ([rowCookie isKindOfClass:[NSString class]]) {
        title = [super customSectionTitleForRowCookie:rowCookie];
    }
    
    return title;
}

- (NSString *)customSectionSubtitleForRowCookie:(id)rowCookie
{
    NSString *subtitle = nil;
    
    if ([rowCookie isKindOfClass:[NSNumber class]]) {
        FLEXViewExplorerRow row = [rowCookie unsignedIntegerValue];
        switch (row) {
            case FLEXViewExplorerRowViewController:
                subtitle = [FLEXRuntimeUtility descriptionForIvarOrPropertyValue:[FLEXUtility viewControllerForView:self.viewToExplore]];
                break;
                
            case FLEXViewExplorerRowPreview:
                break;
            
            case FLEXViewExplorerRowViewControllerForAncestor:
                subtitle = [FLEXRuntimeUtility descriptionForIvarOrPropertyValue:[FLEXUtility viewControllerForAncestralView:self.viewToExplore]];
                break;
        }
    } else if ([rowCookie isKindOfClass:[NSString class]]) {
        return [super customSectionSubtitleForRowCookie:rowCookie];
    }
    
    return subtitle;
}

- (UIViewController *)customSectionDrillInViewControllerForRowCookie:(id)rowCookie
{
    UIViewController *drillInViewController = nil;
    
    if ([rowCookie isKindOfClass:[NSNumber class]]) {
        FLEXViewExplorerRow row = [rowCookie unsignedIntegerValue];
        switch (row) {
            case FLEXViewExplorerRowViewController:
                drillInViewController = [FLEXObjectExplorerFactory explorerViewControllerForObject:[FLEXUtility viewControllerForView:self.viewToExplore]];
                break;
                
            case FLEXViewExplorerRowPreview:
                drillInViewController = [[self class] imagePreviewViewControllerForView:self.viewToExplore];
                break;
                
            case FLEXViewExplorerRowViewControllerForAncestor:
                drillInViewController = [FLEXObjectExplorerFactory explorerViewControllerForObject:[FLEXUtility viewControllerForAncestralView:self.viewToExplore]];
                break;
        }
    } else if ([rowCookie isKindOfClass:[NSString class]]) {
        return [super customSectionDrillInViewControllerForRowCookie:rowCookie];
    }

    return drillInViewController;
}

+ (UIViewController *)imagePreviewViewControllerForView:(UIView *)view
{
    UIViewController *imagePreviewViewController = nil;
    if (!CGRectIsEmpty(view.bounds)) {
        CGSize viewSize = view.bounds.size;
        UIGraphicsBeginImageContextWithOptions(viewSize, NO, 0.0);
        [view drawViewHierarchyInRect:CGRectMake(0, 0, viewSize.width, viewSize.height) afterScreenUpdates:YES];
        UIImage *previewImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        imagePreviewViewController = [[FLEXImagePreviewViewController alloc] initWithImage:previewImage];
    }
    return imagePreviewViewController;
}


#pragma mark - Runtime Adjustment

#define PropertyKey(suffix) kFLEXUtilityAttribute##suffix : @""
#define PropertyKeyGetter(getter) kFLEXUtilityAttributeCustomGetter : NSStringFromSelector(@selector(getter))
#define PropertyKeySetter(setter) kFLEXUtilityAttributeCustomSetter : NSStringFromSelector(@selector(setter))

/// Takes: min iOS version, property name, target class, property type, and a list of attributes
#define FLEXRuntimeUtilityTryAddProperty(iOS_atLeast, name, cls, type, ...) ({ \
    if (@available(iOS iOS_atLeast, *)) { \
        NSMutableDictionary *attrs = [NSMutableDictionary dictionaryWithDictionary:@{ \
            kFLEXUtilityAttributeTypeEncoding : @(type), \
            __VA_ARGS__ \
        }]; \
        [FLEXRuntimeUtility \
            tryAddPropertyWithName:#name \
            attributes:attrs \
            toClass:[cls class] \
        ]; \
    } \
})

/// Takes: min iOS version, property name, target class, property type, and a list of attributes
#define FLEXRuntimeUtilityTryAddNonatomicProperty(iOS_atLeast, name, cls, type, ...) \
    FLEXRuntimeUtilityTryAddProperty(iOS_atLeast, name, cls, @encode(type), PropertyKey(NonAtomic), __VA_ARGS__);
/// Takes: min iOS version, property name, target class, property type (class name), and a list of attributes
#define FLEXRuntimeUtilityTryAddObjectProperty(iOS_atLeast, name, cls, type, ...) \
    FLEXRuntimeUtilityTryAddProperty(iOS_atLeast, name, cls, FLEXEncodeClass(type), PropertyKey(NonAtomic), __VA_ARGS__);

+ (void)initialize
{
    // A quirk of UIView and some other classes: a lot of the `@property`s are
    // not actually properties from the perspective of the runtime.
    //
    // We add these properties to the class at runtime if they haven't been added yet.
    // This way, we can use our property editor to access and change them.
    // The property attributes match the declared attributes in their headers.

    // UIView, public
    FLEXRuntimeUtilityTryAddNonatomicProperty(2, frame, UIView, CGRect);
    FLEXRuntimeUtilityTryAddNonatomicProperty(2, alpha, UIView, CGFloat);
    FLEXRuntimeUtilityTryAddNonatomicProperty(2, clipsToBounds, UIView, BOOL);
    FLEXRuntimeUtilityTryAddNonatomicProperty(2, opaque, UIView, BOOL, PropertyKeyGetter(isOpaque));
    FLEXRuntimeUtilityTryAddNonatomicProperty(2, hidden, UIView, BOOL, PropertyKeyGetter(isHidden));
    FLEXRuntimeUtilityTryAddObjectProperty(2, backgroundColor, UIView, UIColor, PropertyKey(Copy));
    FLEXRuntimeUtilityTryAddObjectProperty(6, constraints, UIView, NSArray, PropertyKey(ReadOnly));
    FLEXRuntimeUtilityTryAddObjectProperty(2, subviews, UIView, NSArray, PropertyKey(ReadOnly));
    FLEXRuntimeUtilityTryAddObjectProperty(2, superview, UIView, UIView, PropertyKey(ReadOnly));
}

@end