添加长按多文字删除

CustomKeyboard/View/KBKeyboardView.m

@@ -17,6 +17,11 @@
 
 static const NSTimeInterval kKBBackspaceLongPressMinDuration = 0.35;
 static const NSTimeInterval kKBBackspaceRepeatInterval = 0.06;
+static const NSTimeInterval kKBBackspaceChunkStartDelay = 0.7;
+static const NSTimeInterval kKBBackspaceChunkRepeatInterval = 0.1;
+static const NSTimeInterval kKBBackspaceChunkFastDelay = 1.4;
+static const NSInteger kKBBackspaceChunkSize = 6;
+static const NSInteger kKBBackspaceChunkSizeFast = 12;
 
 static const NSTimeInterval kKBPreviewShowDuration = 0.08;
 static const NSTimeInterval kKBPreviewHideDuration = 0.06;
@@ -28,6 +33,14 @@ static const CGFloat kKBSpaceWidthMultiplier = 3.0;
 // 第二行字母行的左右占位比例（用于居中）
 static const CGFloat kKBLettersRow2EdgeSpacerMultiplier = 0.5;
 
+typedef NS_ENUM(NSInteger, KBBackspaceChunkClass) {
+    KBBackspaceChunkClassUnknown = 0,
+    KBBackspaceChunkClassWhitespace,
+    KBBackspaceChunkClassASCIIWord,
+    KBBackspaceChunkClassPunctuation,
+    KBBackspaceChunkClassOther
+};
+
 @interface KBKeyboardView ()
 @property (nonatomic, strong) UIView *row1;
 @property (nonatomic, strong) UIView *row2;
@@ -36,6 +49,7 @@ static const CGFloat kKBLettersRow2EdgeSpacerMultiplier = 0.5;
 @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, assign) NSTimeInterval backspaceHoldStartTime;
 @property (nonatomic, strong) KBKeyPreviewView *previewView;
 @end
 
@@ -666,11 +680,12 @@ edgeSpacerMultiplier:(CGFloat)edgeSpacerMultiplier {
                      }];
 }
 
-// 长按退格：按住时以小间隔逐个删除；松手停止。（不使用 NSTimer/DisplayLink）
+// 长按退格：先连续单删，稍后切换为按段删除；松手停止。（不使用 NSTimer/DisplayLink）
 - (void)onBackspaceLongPress:(UILongPressGestureRecognizer *)gr {
     switch (gr.state) {
         case UIGestureRecognizerStateBegan: {
             self.backspaceHoldActive = YES;
+            self.backspaceHoldStartTime = [NSDate date].timeIntervalSinceReferenceDate;
             [self kb_backspaceStep];
         } break;
         case UIGestureRecognizerStateEnded:
@@ -692,17 +707,83 @@ edgeSpacerMultiplier:(CGFloat)edgeSpacerMultiplier {
     id<UITextDocumentProxy> proxy = ivc.textDocumentProxy;
     NSString *before = proxy.documentContextBeforeInput ?: @"";
     if (before.length <= 0) { self.backspaceHoldActive = NO; return; }
-    [proxy deleteBackward]; // 每次仅删 1 个
+    NSTimeInterval elapsed = [NSDate date].timeIntervalSinceReferenceDate - self.backspaceHoldStartTime;
+    NSInteger deleteCount = [self kb_backspaceDeleteCountForContext:before elapsed:elapsed];
+    for (NSInteger i = 0; i < deleteCount; i++) {
+        [proxy deleteBackward];
+    }
 
+    NSTimeInterval interval = [self kb_backspaceRepeatIntervalForElapsed:elapsed];
     __weak typeof(self) weakSelf = self;
     dispatch_after(dispatch_time(DISPATCH_TIME_NOW,
-                                 (int64_t)(kKBBackspaceRepeatInterval * NSEC_PER_SEC)),
+                                 (int64_t)(interval * NSEC_PER_SEC)),
                    dispatch_get_main_queue(), ^{
         __strong typeof(weakSelf) selfStrong = weakSelf;
         [selfStrong kb_backspaceStep];
     });
 }
 
+- (NSTimeInterval)kb_backspaceRepeatIntervalForElapsed:(NSTimeInterval)elapsed {
+    if (elapsed >= kKBBackspaceChunkStartDelay) {
+        return kKBBackspaceChunkRepeatInterval;
+    }
+    return kKBBackspaceRepeatInterval;
+}
+
+- (NSInteger)kb_backspaceDeleteCountForContext:(NSString *)context elapsed:(NSTimeInterval)elapsed {
+    if (elapsed < kKBBackspaceChunkStartDelay) {
+        return 1;
+    }
+    NSInteger maxCount = (elapsed >= kKBBackspaceChunkFastDelay)
+                         ? kKBBackspaceChunkSizeFast : kKBBackspaceChunkSize;
+    return [self kb_backspaceChunkDeleteCountForContext:context maxCount:maxCount];
+}
+
+- (NSInteger)kb_backspaceChunkDeleteCountForContext:(NSString *)context maxCount:(NSInteger)maxCount {
+    if (context.length == 0) { return 1; }
+
+    static NSCharacterSet *whitespaceSet = nil;
+    static NSCharacterSet *asciiWordSet = nil;
+    static NSCharacterSet *punctuationSet = nil;
+    static dispatch_once_t onceToken;
+    dispatch_once(&onceToken, ^{
+        whitespaceSet = [NSCharacterSet whitespaceAndNewlineCharacterSet];
+        asciiWordSet = [NSCharacterSet characterSetWithCharactersInString:
+                        @"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_"];
+        punctuationSet = [NSCharacterSet punctuationCharacterSet];
+    });
+
+    __block NSInteger deleteCount = 0;
+    __block KBBackspaceChunkClass chunkClass = KBBackspaceChunkClassUnknown;
+    [context enumerateSubstringsInRange:NSMakeRange(0, context.length)
+                                options:NSStringEnumerationByComposedCharacterSequences | NSStringEnumerationReverse
+                             usingBlock:^(NSString *substring, __unused NSRange substringRange, __unused NSRange enclosingRange, BOOL *stop) {
+        if (substring.length == 0) { return; }
+        KBBackspaceChunkClass currentClass = KBBackspaceChunkClassOther;
+        if ([substring rangeOfCharacterFromSet:whitespaceSet].location != NSNotFound) {
+            currentClass = KBBackspaceChunkClassWhitespace;
+        } else if ([substring rangeOfCharacterFromSet:asciiWordSet].location != NSNotFound) {
+            currentClass = KBBackspaceChunkClassASCIIWord;
+        } else if ([substring rangeOfCharacterFromSet:punctuationSet].location != NSNotFound) {
+            currentClass = KBBackspaceChunkClassPunctuation;
+        }
+
+        if (chunkClass == KBBackspaceChunkClassUnknown) {
+            chunkClass = currentClass;
+        } else if (chunkClass != currentClass) {
+            *stop = YES;
+            return;
+        }
+
+        deleteCount += 1;
+        if (deleteCount >= maxCount) {
+            *stop = YES;
+        }
+    }];
+
+    return MAX(deleteCount, 1);
+}
+
 #pragma mark - Lazy
 
 - (UIView *)row1 { if (!_row1) _row1 = [UIView new]; return _row1; }