UIButton+QMUI.m

/**
 * Tencent is pleased to support the open source community by making QMUI_iOS available.
 * Copyright (C) 2016-2021 THL A29 Limited, a Tencent company. All rights reserved.
 * Licensed under the MIT License (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
 * http://opensource.org/licenses/MIT
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
 */

//
//  UIButton+QMUI.m
//  qmui
//
//  Created by QMUI Team on 15/7/20.
//

#import "UIButton+QMUI.h"
#import "QMUICore.h"
#import "UIImage+QMUI.h"

@interface UIButton ()

@property(nonatomic, strong) NSMutableDictionary<NSNumber *, NSDictionary<NSAttributedStringKey, id> *> *qbt_titleAttributes;
@property(nonatomic, strong) NSMutableSet<NSNumber *> *qbt_statesWithTitle;

@property(nonatomic, strong) NSMutableDictionary<NSNumber *, UIColor *> *qbt_imageTintColors;
@property(nonatomic, strong) NSMutableSet<NSNumber *> *qbt_statesWithImageTintColor;

@end

@implementation UIButton (QMUI)

QMUISynthesizeIdStrongProperty(qbt_titleAttributes, setQbt_titleAttributes)
QMUISynthesizeIdStrongProperty(qbt_statesWithTitle, setQbt_statesWithTitle)
QMUISynthesizeIdStrongProperty(qbt_imageTintColors, setQbt_imageTintColors)
QMUISynthesizeIdStrongProperty(qbt_statesWithImageTintColor, setQbt_statesWithImageTintColor)

+ (void)load {
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        
        OverrideImplementation([UIButton class], @selector(setTitle:forState:), ^id(__unsafe_unretained Class originClass, SEL originCMD, IMP (^originalIMPProvider)(void)) {
            return ^(UIButton *selfObject, NSString *title, UIControlState state) {
                
                if (title.length) {
                    if (!selfObject.qbt_statesWithTitle) {
                        selfObject.qbt_statesWithTitle = [[NSMutableSet alloc] init];
                    }
                    if (state == UIControlStateNormal) {
                        [selfObject.qbt_statesWithTitle addObject:@(state)];
                    } else {
                        NSString *normalTitle = [selfObject titleForState:UIControlStateNormal] ?: [selfObject attributedTitleForState:UIControlStateNormal].string;
                        if (![title isEqualToString:normalTitle]) {
                            [selfObject.qbt_statesWithTitle addObject:@(state)];
                        } else {
                            [selfObject.qbt_statesWithTitle removeObject:@(state)];
                        }
                    }
                } else {
                    [selfObject.qbt_statesWithTitle removeObject:@(state)];
                }
                
                // call super
                void (*originSelectorIMP)(id, SEL, NSString *, UIControlState);
                originSelectorIMP = (void (*)(id, SEL, NSString *, UIControlState))originalIMPProvider();
                originSelectorIMP(selfObject, originCMD, title, state);
                
                [selfObject qbt_syncTitleByStates];
            };
        });
        
        ExtendImplementationOfVoidMethodWithoutArguments([UIButton class], @selector(layoutSubviews), ^(UIButton *selfObject) {
            // 临时解决 iOS 13 开启了粗体文本（Bold Text）导致 UIButton Title 显示不完整 https://github.com/Tencent/QMUI_iOS/issues/620
            if (UIAccessibilityIsBoldTextEnabled()) {
                [selfObject.titleLabel sizeToFit];
            }
        });
    });
}

- (instancetype)qmui_initWithImage:(UIImage *)image title:(NSString *)title {
    // 非 init 开头的方法，无法给 self 赋值，所以无法像常规的写法一样 self = [self init]
    BeginIgnoreClangWarning(-Wunused-value)
    [self init];
    EndIgnoreClangWarning
    
    [self setImage:image forState:UIControlStateNormal];
    [self setTitle:title forState:UIControlStateNormal];
    return self;
}

- (void)qmui_calculateHeightAfterSetAppearance {
    [self setTitle:@"测" forState:UIControlStateNormal];
    [self sizeToFit];
    [self setTitle:nil forState:UIControlStateNormal];
}

#pragma mark - TitleAttributes

- (void)qmui_setTitleAttributes:(NSDictionary<NSAttributedStringKey,id> *)attributes forState:(UIControlState)state {
    if (!attributes && self.qbt_titleAttributes) {
        [self.qbt_titleAttributes removeObjectForKey:@(state)];
        return;
    }
    
    [UIButton qbt_swizzleForTitleAttributesIfNeeded];
    
    if (!self.qbt_titleAttributes) {
        self.qbt_titleAttributes = [[NSMutableDictionary alloc] init];
    }
    
    // 从 Normal 同步样式到其他 state
    if (state != UIControlStateNormal && self.qbt_titleAttributes[@(UIControlStateNormal)]) {
        NSMutableDictionary<NSAttributedStringKey, id> *temp = attributes.mutableCopy;
        NSDictionary<NSAttributedStringKey, id> *normalAttributes = self.qbt_titleAttributes[@(UIControlStateNormal)];
        for (NSAttributedStringKey key in normalAttributes.allKeys) {
            if (!temp[key]) {
                temp[key] = normalAttributes[key];
            }
        }
        attributes = temp.copy;
    }
    
    self.qbt_titleAttributes[@(state)] = attributes;
    
    // 确保调用此方法设置 attributes 之前已经通过 setTitle:forState: 设置的文字也能应用上新的 attributes
    [self qbt_syncTitleByStates];
    
    // 一个系统的不好的特性（bug?）：如果你给 UIControlStateHighlighted（或者 normal 之外的任何 state）设置了包含 NSFont/NSKern/NSUnderlineAttributeName 之类的 attributedString ，但又仅用 setTitle:forState: 给 UIControlStateNormal 设置了普通的 string ，则按钮从 highlighted 切换回 normal 状态时，font 之类的属性依然会停留在 highlighted 时的状态
    // 为了解决这个问题，我们要确保一旦有 normal 之外的 state 通过设置 qbt_titleAttributes 属性而导致使用了 attributedString，则 normal 也必须使用 attributedString
    if (self.qbt_titleAttributes.count && !self.qbt_titleAttributes[@(UIControlStateNormal)]) {
        [self qmui_setTitleAttributes:@{} forState:UIControlStateNormal];
    }
}

// 如果 normal 用了 attributedTitle，那么其他的 state 都必须用 attributedTitle，否则就无法展示出来
- (void)qbt_syncTitleByStates {
    if (!self.qbt_titleAttributes.count) return;
    for (NSNumber *stateValue in self.qbt_statesWithTitle) {
        UIControlState state = stateValue.unsignedIntegerValue;
        NSString *title = [self titleForState:state];
        NSDictionary<NSAttributedStringKey, id> *attributes = self.qbt_titleAttributes[stateValue] ?: self.qbt_titleAttributes[@(UIControlStateNormal)];
        NSAttributedString *string = [[NSAttributedString alloc] initWithString:title attributes:attributes];
        string = [UIButton qbt_attributedStringByRemovingLastKern:string];
        [self setAttributedTitle:string forState:state];
    }
}

+ (void)qbt_swizzleForTitleAttributesIfNeeded {
    [QMUIHelper executeBlock:^{
        // 如果之前已经设置了此 state 下的文字颜色，则覆盖掉之前的颜色
        OverrideImplementation([UIButton class], @selector(setTitleColor:forState:), ^id(__unsafe_unretained Class originClass, SEL originCMD, IMP (^originalIMPProvider)(void)) {
            return ^(UIButton *selfObject, UIColor *color, UIControlState state) {
                
                // call super
                void (*originSelectorIMP)(id, SEL, UIColor *, UIControlState);
                originSelectorIMP = (void (*)(id, SEL, UIColor *, UIControlState))originalIMPProvider();
                originSelectorIMP(selfObject, originCMD, color, state);
                
                NSDictionary *attributes = selfObject.qbt_titleAttributes[@(state)];
                if (attributes) {
                    NSMutableDictionary<NSAttributedStringKey, id> *newAttributes = attributes.mutableCopy;
                    newAttributes[NSForegroundColorAttributeName] = color;
                    [selfObject qmui_setTitleAttributes:newAttributes.copy forState:state];
                }
            };
        });
    } oncePerIdentifier:@"UIButton (QMUI) titleAttributes"];
}

// 去除最后一个字的 kern 效果，避免字符串尾部出现多余的空白
+ (NSAttributedString *)qbt_attributedStringByRemovingLastKern:(NSAttributedString *)string {
    if (!string.length) {
        return string;
    }
    NSMutableAttributedString *attributedString = string.mutableCopy;
    [attributedString removeAttribute:NSKernAttributeName range:NSMakeRange(string.length - 1, 1)];
    return attributedString.copy;
}

#pragma mark - ImageTintColor

- (void)qmui_setImageTintColor:(UIColor *)color forState:(UIControlState)state {
    if (!color && self.qbt_imageTintColors) {
        [self.qbt_imageTintColors removeObjectForKey:@(state)];
        return;
    }
    
    [UIButton qbt_swizzleForImageTintColorIfNeeded];
    
    if (!self.qbt_imageTintColors) {
        self.qbt_imageTintColors = [[NSMutableDictionary alloc] init];
    }
    self.qbt_imageTintColors[@(state)] = color;
    
    UIImage *stateImage = [self imageForState:state];
    if (!stateImage) return;
    stateImage = [[stateImage qmui_imageWithTintColor:color] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
    [self setImage:stateImage forState:state];
}

+ (void)qbt_swizzleForImageTintColorIfNeeded {
    [QMUIHelper executeBlock:^{
        OverrideImplementation([UIButton class], @selector(setImage:forState:), ^id(__unsafe_unretained Class originClass, SEL originCMD, IMP (^originalIMPProvider)(void)) {
            return ^(UIButton *selfObject, UIImage *image, UIControlState state) {
                
                BOOL isFirstSetImage = image && ![selfObject imageForState:UIControlStateNormal];
                
                UIColor *imageTintColor = selfObject.qbt_imageTintColors[@(state)];
                if (imageTintColor) {
                    image = [[image qmui_imageWithTintColor:imageTintColor] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
                }
                
                // call super
                void (*originSelectorIMP)(id, SEL, UIImage *, UIControlState);
                originSelectorIMP = (void (*)(id, SEL, UIImage *, UIControlState))originalIMPProvider();
                originSelectorIMP(selfObject, originCMD, image, state);
                
                if (isFirstSetImage) {
                    [selfObject.qbt_imageTintColors enumerateKeysAndObjectsUsingBlock:^(NSNumber * _Nonnull key, UIColor * _Nonnull color, BOOL * _Nonnull stop) {
                        UIControlState s = key.unsignedIntegerValue;
                        if (s != state) {// 避免死循环
                            UIImage *stateImage = [selfObject imageForState:s];
                            if (stateImage) {
                                stateImage = [[stateImage qmui_imageWithTintColor:color] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
                                [selfObject setImage:stateImage forState:s];
                            }
                        }
                    }];
                }
            };
        });
    } oncePerIdentifier:@"UIButton (QMUI) titleAttributes"];
}

@end