keyboard/CustomKeyboard/View/KBKeyButton.m

//
//  KBKeyButton.m
//  CustomKeyboard
//

#import "KBKeyButton.h"
#import "KBKey.h"
#import "KBSkinManager.h"

@interface KBKeyButton ()
// 内部缓存：便于从按钮查找到所属的 KBKeyboardView
@property (nonatomic, weak, readonly) UIView *kb_keyboardContainer;
@property (nonatomic, strong) UIImageView *normalImageView; /// 没有皮肤的时候展示
@property (nonatomic, strong) UIColor *baseBackgroundColor; /// 无按下状态下，由皮肤/主题决定的底色（由 normalImageView 展示）

@end

@implementation KBKeyButton

- (instancetype)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        [self addSubview:self.normalImageView];
        self.normalImageView.translatesAutoresizingMaskIntoConstraints = NO;
        [NSLayoutConstraint activateConstraints:@[
            [self.normalImageView.topAnchor constraintEqualToAnchor:self.topAnchor],
            [self.normalImageView.bottomAnchor constraintEqualToAnchor:self.bottomAnchor],
            [self.normalImageView.leadingAnchor constraintEqualToAnchor:self.leadingAnchor constant:2],
            [self.normalImageView.trailingAnchor constraintEqualToAnchor:self.trailingAnchor constant:-2],
        ]];
        [self applyDefaultStyle];
    }
    return self;
}

- (void)applyDefaultStyle {
    self.titleLabel.font = [UIFont systemFontOfSize:18 weight:UIFontWeightSemibold];
    KBSkinTheme *t = [KBSkinManager shared].current;
    [self setTitleColor:t.keyTextColor forState:UIControlStateNormal];
    [self setTitleColor:t.keyTextColor forState:UIControlStateHighlighted];
    // 颜色由 normalImageView 控制，按钮本身保持透明，避免叠加背景影响视觉
    self.backgroundColor = [UIColor clearColor];
    self.layer.cornerRadius = 6.0;      // 圆角
    self.layer.masksToBounds = NO;
    self.layer.shadowColor = [UIColor colorWithWhite:0 alpha:0.1].CGColor; // 阴影效果
    self.layer.shadowOpacity = 1.0;
    self.layer.shadowOffset = CGSizeMake(0, 1);
    self.layer.shadowRadius = 1.5;

    // 初始状态下根据主题设置底色（给没有皮肤图的按键使用）
    [self refreshStateAppearance];

    // 懒创建图标视图，用于后续皮肤按键小图标展示
    if (!self.iconView) {
        UIImageView *iv = [[UIImageView alloc] initWithFrame:CGRectZero];
        // 作为按键的整块皮肤背景，铺满整个按钮区域
        iv.contentMode = UIViewContentModeScaleToFill;
        iv.clipsToBounds = YES;
        iv.translatesAutoresizingMaskIntoConstraints = NO;
        [self addSubview:iv];
        // 让皮肤图片撑满整个按钮
        [NSLayoutConstraint activateConstraints:@[
            [iv.topAnchor constraintEqualToAnchor:self.topAnchor],
            [iv.bottomAnchor constraintEqualToAnchor:self.bottomAnchor],
            [iv.leadingAnchor constraintEqualToAnchor:self.leadingAnchor constant:2],
            [iv.trailingAnchor constraintEqualToAnchor:self.trailingAnchor constant:-2],
        ]];
        self.iconView = iv;

        // 文字保持居中；若需要显示文字，则覆盖在皮肤图片之上
        self.titleEdgeInsets = UIEdgeInsetsZero;
        [self bringSubviewToFront:self.titleLabel];
    }
}

- (void)setKey:(KBKey *)key {
    _key = key;
}

- (void)setHighlighted:(BOOL)highlighted {
    [super setHighlighted:highlighted];
    // 按下时整体做一个等比缩放动画，不改背景色和透明度。
    // 这样无论是纯文字键还是整块皮肤图，都有统一的“按下”视觉反馈。
    CGFloat scale = highlighted ? 0.9 : 1.0; // 可根据手感微调 0.9~0.95

    // 没有皮肤图片时，normalImageView 做灰度按下效果
    BOOL hasIcon = (self.iconView.image != nil);
    UIColor *normalBgColor = self.baseBackgroundColor ?: [UIColor whiteColor];
    UIColor *highlightBgColor = [self kb_darkerColorForColor:normalBgColor];

    [UIView animateWithDuration:0.08
                          delay:0
                        options:UIViewAnimationOptionBeginFromCurrentState | UIViewAnimationOptionCurveEaseOut
                     animations:^{
                         if (!hasIcon && !self.normalImageView.hidden) {
                             self.normalImageView.backgroundColor = highlighted ? highlightBgColor : normalBgColor;
                         }
                         self.transform = CGAffineTransformMakeScale(scale, scale);
                     }
                     completion:nil];

    // 将“按下/抬起”事件转发给键盘视图，用于显示/隐藏顶部预览气泡。
    UIView *container = self.kb_keyboardContainer;
    if ([container respondsToSelector:@selector(showPreviewForButton:)] &&
        [container respondsToSelector:@selector(hidePreview)]) {
        if (highlighted) {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Warc-performSelector-leaks"
            [container performSelector:@selector(showPreviewForButton:) withObject:self];
#pragma clang diagnostic pop
        } else {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Warc-performSelector-leaks"
            [container performSelector:@selector(hidePreview)];
#pragma clang diagnostic pop
        }
    }
}

- (void)setSelected:(BOOL)selected {
    [super setSelected:selected];
    [self refreshStateAppearance];
}

- (void)refreshStateAppearance {
    // 选中态用于 Shift/CapsLock 等特殊按键的高亮显示
    KBSkinTheme *t = [KBSkinManager shared].current;
    UIColor *base = nil;
    if (self.isSelected) {
        base = t.keyHighlightBackground ?: t.keyBackground;
    } else {
        base = t.keyBackground;
    }
    if (!base) {
        base = [UIColor whiteColor];
    }

    self.baseBackgroundColor = base;
    // 按键背景统一由 normalImageView 控制，按钮本身透明
    self.backgroundColor = [UIColor clearColor];

    // 有皮肤图时仅展示 icon，不再显示普通背景色
    if (self.iconView.image != nil || self.normalImageView.hidden) {
        return;
    }

    self.normalImageView.backgroundColor = base;
}

- (void)applyThemeForCurrentKey {
    // 根据皮肤映射加载图标（若有），支持大小写变体：
    // - identifier: 逻辑按键标识（如 letter_q）
    // - caseVariant: 0/1/2 => 无变体/小写/大写
    NSString *identifier = self.key.identifier;
    NSInteger variant = (NSInteger)self.key.caseVariant;
    KBSkinManager *skinManager = [KBSkinManager shared];
    UIImage *iconImg = [skinManager iconImageForKeyIdentifier:identifier caseVariant:variant];

    if (!iconImg && [identifier isEqualToString:@"ai"]) {
        NSString *skinId = skinManager.current.skinId ?: @"";
        BOOL usingDefaultSkin = (skinId.length == 0 || [skinId isEqualToString:@"default"]);
        if (usingDefaultSkin) {
            iconImg = [UIImage imageNamed:@"ai_key_icon"];
        }
    }

    // 设置整块按键背景图（若有）
    self.iconView.image = iconImg;
    self.iconView.hidden = (iconImg == nil);

    BOOL hasIcon = (iconImg != nil);
    self.normalImageView.hidden = hasIcon;
    if (hasIcon) {
        // 有图标：仅显示图片，完全隐藏文字
        [self setTitle:@"" forState:UIControlStateNormal];
        [self setTitle:@"" forState:UIControlStateHighlighted];
        [self setTitle:@"" forState:UIControlStateSelected];
        self.titleLabel.hidden = YES;
        self.normalImageView.backgroundColor = [UIColor clearColor];
    } else {
        // 无图标：按键标题正常显示（使用 key.title），并根据 hidden_keys 决定要不要隐藏
        [self setTitle:self.key.title forState:UIControlStateNormal];
        BOOL hideTextBySkin = [[KBSkinManager shared] shouldHideKeyTextForIdentifier:identifier];
        self.titleLabel.hidden = hideTextBySkin;
    }
}

- (UIImageView *)normalImageView{
    if (!_normalImageView) {
        _normalImageView = [[UIImageView alloc] init];
        // 初始给一个默认色，后续会由 refreshStateAppearance / 皮肤统一覆盖
        _normalImageView.backgroundColor = [UIColor whiteColor];
        _normalImageView.layer.cornerRadius = 6;
        _normalImageView.layer.masksToBounds = true;
    }
    return _normalImageView;
}

/// 在当前底色的基础上略微变暗，作为按下时的“灰度”效果
- (UIColor *)kb_darkerColorForColor:(UIColor *)color {
    if (!color) return [UIColor colorWithWhite:0.9 alpha:1.0];

    CGFloat h = 0, s = 0, b = 0, a = 0;
    if ([color getHue:&h saturation:&s brightness:&b alpha:&a]) {
        return [UIColor colorWithHue:h saturation:s brightness:MAX(b * 0.9, 0.0) alpha:a];
    }

    CGFloat white = 0;
    if ([color getWhite:&white alpha:&a]) {
        return [UIColor colorWithWhite:MAX(white * 0.9, 0.0) alpha:a];
    }

    return color;
}

@end

@implementation KBKeyButton (KBKeyboardContainer)

- (UIView *)kb_keyboardContainer {
    UIView *v = self.superview;
    while (v) {
        // KBKeyboardView 是当前容器类型，这里用类名字符串避免直接引用头文件死循环
        if ([NSStringFromClass(v.class) isEqualToString:@"KBKeyboardView"]) {
            return v;
        }
        v = v.superview;
    }
    return nil;
}

@end