添加按钮文字预览提示

CustomKeyboard/View/KBKeyButton.h

@@ -10,6 +10,7 @@
 @interface KBKeyButton : UIButton
 
 @property (nonatomic, strong) KBKey *key;
+@property (nonatomic, strong) UIImageView *iconView;
 
 /// 配置基础样式（背景、圆角等）。创建按钮时调用。
 - (void)applyDefaultStyle;

CustomKeyboard/View/KBKeyButton.m

@@ -8,7 +8,8 @@
 #import "KBSkinManager.h"
 
 @interface KBKeyButton ()
-@property (nonatomic, strong) UIImageView *iconView;
+// 内部缓存：便于从按钮查找到所属的 KBKeyboardView
+@property (nonatomic, weak, readonly) UIView *kb_keyboardContainer;
 @end
 
 @implementation KBKeyButton
@@ -63,10 +64,8 @@
 
 - (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。
-    NSLog(@"来了老弟=====");
     CGFloat scale = highlighted ? 0.9 : 1.0; // 可根据手感微调 0.9~0.95
     [UIView animateWithDuration:0.08
                           delay:0
@@ -75,6 +74,23 @@
                          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 {
@@ -124,3 +140,19 @@
 }
 
 @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

CustomKeyboard/View/KBKeyPreviewView.h

@@ -0,0 +1,21 @@
+//
+//  KBKeyPreviewView.h
+//  CustomKeyboard
+//
+
+#import <UIKit/UIKit.h>
+
+@class KBKey;
+
+NS_ASSUME_NONNULL_BEGIN
+
+/// 按键按下时显示的气泡预览视图（类似系统键盘上方弹出的放大字母）。
+@interface KBKeyPreviewView : UIView
+
+/// 配置预览内容：字符与可选图标。
+- (void)configureWithKey:(KBKey *)key icon:(nullable UIImage *)icon;
+
+@end
+
+NS_ASSUME_NONNULL_END
+

CustomKeyboard/View/KBKeyPreviewView.m

@@ -0,0 +1,56 @@
+//
+//  KBKeyPreviewView.m
+//  CustomKeyboard
+//
+
+#import "KBKeyPreviewView.h"
+#import "KBKey.h"
+
+@interface KBKeyPreviewView ()
+@property (nonatomic, strong) UILabel *label;
+@property (nonatomic, strong) UIImageView *iconView;
+@end
+
+@implementation KBKeyPreviewView
+
+- (instancetype)initWithFrame:(CGRect)frame {
+    if (self = [super initWithFrame:frame]) {
+        self.backgroundColor = [UIColor colorWithWhite:1 alpha:1.0];
+        self.layer.cornerRadius = 8.0;
+        self.layer.masksToBounds = YES;
+        self.layer.borderWidth = 0.5;
+        self.layer.borderColor = [UIColor colorWithWhite:0 alpha:0.15].CGColor;
+        self.layer.shadowColor = [UIColor colorWithWhite:0 alpha:0.3].CGColor;
+        self.layer.shadowOpacity = 0.6;
+        self.layer.shadowOffset = CGSizeMake(0, 2);
+        self.layer.shadowRadius = 4.0;
+
+//        _iconView = [[UIImageView alloc] initWithFrame:CGRectZero];
+//        _iconView.contentMode = UIViewContentModeScaleAspectFit;
+//        _iconView.translatesAutoresizingMaskIntoConstraints = NO;
+//        [self addSubview:_iconView];
+
+        _label = [[UILabel alloc] initWithFrame:CGRectZero];
+        _label.font = [UIFont systemFontOfSize:28 weight:UIFontWeightSemibold];
+        _label.textAlignment = NSTextAlignmentCenter;
+        _label.textColor = [UIColor blackColor];
+        _label.translatesAutoresizingMaskIntoConstraints = NO;
+        [self addSubview:_label];
+
+        // 预览只使用文本：尽量靠近顶部显示，上下留少量安全距离。
+        [NSLayoutConstraint activateConstraints:@[
+            [_label.leadingAnchor constraintEqualToAnchor:self.leadingAnchor constant:4],
+            [_label.trailingAnchor constraintEqualToAnchor:self.trailingAnchor constant:-4],
+            [_label.topAnchor constraintEqualToAnchor:self.topAnchor constant:2],
+            [_label.bottomAnchor constraintEqualToAnchor:self.bottomAnchor constant:-2],
+        ]];
+    }
+    return self;
+}
+
+- (void)configureWithKey:(KBKey *)key icon:(UIImage *)icon {
+    NSString *text = key.output.length > 0 ? key.output : key.title;
+    self.label.text = text;
+}
+
+@end

CustomKeyboard/View/KBKeyboardView.m

@@ -8,6 +8,7 @@
 #import "KBKey.h"
 #import "KBResponderUtils.h" // 封装的响应链工具
 #import "KBSkinManager.h"
+#import "KBKeyPreviewView.h"
 
 @interface KBKeyboardView ()
 @property (nonatomic, strong) UIView *row1;
@@ -17,6 +18,7 @@
 @property (nonatomic, strong) NSArray<NSArray<KBKey *> *> *keysForRows;
 // 长按退格的一次次删除控制标记（不使用 NSTimer，仅用 GCD 递归调度）
 @property (nonatomic, assign) BOOL backspaceHoldActive;
+@property (nonatomic, strong) KBKeyPreviewView *previewView;
 @end
 
 @implementation KBKeyboardView
@@ -463,6 +465,53 @@
     }
 }
 
+// 在字符键按下时，显示一个上方气泡预览（类似系统键盘）。
+- (void)showPreviewForButton:(KBKeyButton *)button {
+    KBKey *key = button.key;
+    if (key.type != KBKeyTypeCharacter) return;
+
+    if (!self.previewView) {
+        self.previewView = [[KBKeyPreviewView alloc] initWithFrame:CGRectZero];
+        self.previewView.hidden = YES;
+        [self addSubview:self.previewView];
+    }
+
+    [self.previewView configureWithKey:key icon:button.iconView.image];
+
+    // 计算预览视图位置：在按钮上方稍微偏上
+    CGRect btnFrameInSelf = [button convertRect:button.bounds toView:self];
+    CGFloat previewWidth  = MAX(CGRectGetWidth(btnFrameInSelf) * 1.4, 42.0);
+    CGFloat previewHeight = CGRectGetHeight(btnFrameInSelf) * 1.2;
+    CGFloat centerX = CGRectGetMidX(btnFrameInSelf);
+    CGFloat centerY = CGRectGetMinY(btnFrameInSelf) - previewHeight * 0.6;
+
+    self.previewView.frame = CGRectMake(0, 0, previewWidth, previewHeight);
+    self.previewView.center = CGPointMake(centerX, centerY);
+    self.previewView.alpha = 0.0;
+    self.previewView.hidden = NO;
+
+    [UIView animateWithDuration:0.08
+                          delay:0
+                        options:UIViewAnimationOptionBeginFromCurrentState | UIViewAnimationOptionCurveEaseOut
+                     animations:^{
+                         self.previewView.alpha = 1.0;
+                     }
+                     completion:nil];
+}
+
+- (void)hidePreview {
+    if (!self.previewView || self.previewView.isHidden) return;
+    [UIView animateWithDuration:0.06
+                          delay:0
+                        options:UIViewAnimationOptionBeginFromCurrentState | UIViewAnimationOptionCurveEaseIn
+                     animations:^{
+                         self.previewView.alpha = 0.0;
+                     }
+                     completion:^(BOOL finished) {
+                         self.previewView.hidden = YES;
+                     }];
+}
+
 // 长按退格：按住时以小间隔逐个删除；松手停止。（不使用 NSTimer/DisplayLink）
 - (void)onBackspaceLongPress:(UILongPressGestureRecognizer *)gr {
     switch (gr.state) {