1

CustomKeyboard/View/KBKeyboardView.m

@@ -22,6 +22,10 @@ static const NSTimeInterval kKBBackspaceChunkRepeatInterval = 0.1;
 static const NSTimeInterval kKBBackspaceChunkFastDelay = 1.4;
 static const NSInteger kKBBackspaceChunkSize = 6;
 static const NSInteger kKBBackspaceChunkSizeFast = 12;
+static const CGFloat kKBBackspaceClearLabelCornerRadius = 8.0;
+static const CGFloat kKBBackspaceClearLabelHeight = 26.0;
+static const CGFloat kKBBackspaceClearLabelPaddingX = 10.0;
+static const CGFloat kKBBackspaceClearLabelTopGap = 6.0;
 
 static const NSTimeInterval kKBPreviewShowDuration = 0.08;
 static const NSTimeInterval kKBPreviewHideDuration = 0.06;
@@ -50,6 +54,10 @@ typedef NS_ENUM(NSInteger, KBBackspaceChunkClass) {
 // 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, assign) BOOL backspaceChunkModeActive;
+@property (nonatomic, assign) BOOL backspaceClearHighlighted;
+@property (nonatomic, weak) KBKeyButton *backspaceButton;
+@property (nonatomic, strong) UILabel *backspaceClearLabel;
 @property (nonatomic, strong) KBKeyPreviewView *previewView;
 @end
 
@@ -110,6 +118,10 @@ typedef NS_ENUM(NSInteger, KBBackspaceChunkClass) {
 #pragma mark - Public
 
 - (void)reloadKeys {
+    self.backspaceButton = nil;
+    self.backspaceChunkModeActive = NO;
+    self.backspaceClearHighlighted = NO;
+    [self kb_hideBackspaceClearLabel];
     // 移除旧按钮
     for (UIView *row in @[self.row1, self.row2, self.row3, self.row4]) {
         [row.subviews makeObjectsPerformSelector:@selector(removeFromSuperview)];
@@ -391,8 +403,10 @@ edgeSpacerMultiplier:(CGFloat)edgeSpacerMultiplier {
             [[UILongPressGestureRecognizer alloc] initWithTarget:self
                                                           action:@selector(onBackspaceLongPress:)];
             lp.minimumPressDuration = kKBBackspaceLongPressMinDuration;
+            lp.allowableMovement = CGFLOAT_MAX;
             lp.cancelsTouchesInView = YES; // 被识别为长按时，取消普通点击
             [btn addGestureRecognizer:lp];
+            self.backspaceButton = btn;
         }
 
         // Shift 按钮选中态随大小写状态变化
@@ -686,12 +700,18 @@ edgeSpacerMultiplier:(CGFloat)edgeSpacerMultiplier {
         case UIGestureRecognizerStateBegan: {
             self.backspaceHoldActive = YES;
             self.backspaceHoldStartTime = [NSDate date].timeIntervalSinceReferenceDate;
+            self.backspaceChunkModeActive = NO;
+            [self kb_setBackspaceClearHighlighted:NO];
+            [self kb_hideBackspaceClearLabel];
             [self kb_backspaceStep];
         } break;
+        case UIGestureRecognizerStateChanged: {
+            [self kb_handleBackspaceLongPressChanged:gr];
+        } break;
         case UIGestureRecognizerStateEnded:
         case UIGestureRecognizerStateCancelled:
         case UIGestureRecognizerStateFailed: {
-            self.backspaceHoldActive = NO;
+            [self kb_handleBackspaceLongPressEnded:gr];
         } break;
         default: break;
     }
@@ -709,6 +729,10 @@ edgeSpacerMultiplier:(CGFloat)edgeSpacerMultiplier {
     if (before.length <= 0) { self.backspaceHoldActive = NO; return; }
     NSTimeInterval elapsed = [NSDate date].timeIntervalSinceReferenceDate - self.backspaceHoldStartTime;
     NSInteger deleteCount = [self kb_backspaceDeleteCountForContext:before elapsed:elapsed];
+    if (!self.backspaceChunkModeActive && elapsed >= kKBBackspaceChunkStartDelay) {
+        self.backspaceChunkModeActive = YES;
+        [self kb_showBackspaceClearLabelIfNeeded];
+    }
     for (NSInteger i = 0; i < deleteCount; i++) {
         [proxy deleteBackward];
     }
@@ -784,6 +808,144 @@ edgeSpacerMultiplier:(CGFloat)edgeSpacerMultiplier {
     return MAX(deleteCount, 1);
 }
 
+- (void)kb_handleBackspaceLongPressChanged:(UILongPressGestureRecognizer *)gr {
+    if (!self.backspaceHoldActive) { return; }
+    NSTimeInterval elapsed = [NSDate date].timeIntervalSinceReferenceDate - self.backspaceHoldStartTime;
+    if (elapsed < kKBBackspaceChunkStartDelay) { return; }
+    [self kb_showBackspaceClearLabelIfNeeded];
+    CGPoint point = [gr locationInView:self];
+    BOOL inside = [self kb_isPointInsideBackspaceClearLabel:point];
+    [self kb_setBackspaceClearHighlighted:inside];
+}
+
+- (void)kb_handleBackspaceLongPressEnded:(UILongPressGestureRecognizer *)gr {
+    BOOL shouldClear = self.backspaceClearHighlighted;
+    if (!shouldClear && gr) {
+        CGPoint point = [gr locationInView:self];
+        shouldClear = [self kb_isPointInsideBackspaceClearLabel:point];
+    }
+    self.backspaceHoldActive = NO;
+    self.backspaceChunkModeActive = NO;
+    [self kb_hideBackspaceClearLabel];
+    if (shouldClear) {
+        [self kb_clearAllInput];
+    }
+}
+
+- (void)kb_showBackspaceClearLabelIfNeeded {
+    if (!self.backspaceButton) { return; }
+    UILabel *label = self.backspaceClearLabel;
+    [self kb_refreshBackspaceClearLabelColors];
+    if (!label.superview) {
+        [self addSubview:label];
+    }
+    [self kb_updateBackspaceClearLabelFrame];
+    [self bringSubviewToFront:label];
+    if (label.hidden) {
+        label.alpha = 0.0;
+        label.hidden = NO;
+        [UIView animateWithDuration:0.12 animations:^{
+            label.alpha = 1.0;
+        }];
+    }
+}
+
+- (void)kb_hideBackspaceClearLabel {
+    if (!_backspaceClearLabel || _backspaceClearLabel.hidden) { return; }
+    _backspaceClearLabel.hidden = YES;
+    _backspaceClearLabel.alpha = 1.0;
+    [self kb_setBackspaceClearHighlighted:NO];
+}
+
+- (void)kb_updateBackspaceClearLabelFrame {
+    if (!self.backspaceButton || !self.backspaceClearLabel) { return; }
+    CGRect btnFrame = [self.backspaceButton convertRect:self.backspaceButton.bounds toView:self];
+    UILabel *label = self.backspaceClearLabel;
+    CGSize textSize = [label sizeThatFits:CGSizeMake(CGFLOAT_MAX, kKBBackspaceClearLabelHeight)];
+    CGFloat width = MAX(textSize.width + kKBBackspaceClearLabelPaddingX * 2.0, 60.0);
+    CGFloat height = kKBBackspaceClearLabelHeight;
+    CGFloat x = CGRectGetMidX(btnFrame) - width * 0.5;
+    CGFloat y = CGRectGetMinY(btnFrame) - height - kKBBackspaceClearLabelTopGap;
+    if (x < kKBRowHorizontalInset) { x = kKBRowHorizontalInset; }
+    if (x + width > CGRectGetWidth(self.bounds) - kKBRowHorizontalInset) {
+        x = CGRectGetWidth(self.bounds) - kKBRowHorizontalInset - width;
+    }
+    if (y < 0) { y = 0; }
+    label.frame = CGRectIntegral(CGRectMake(x, y, width, height));
+}
+
+- (BOOL)kb_isPointInsideBackspaceClearLabel:(CGPoint)point {
+    if (!self.backspaceClearLabel || self.backspaceClearLabel.hidden) { return NO; }
+    [self layoutIfNeeded];
+    return CGRectContainsPoint(self.backspaceClearLabel.frame, point);
+}
+
+- (void)kb_setBackspaceClearHighlighted:(BOOL)highlighted {
+    if (self.backspaceClearHighlighted == highlighted) { return; }
+    self.backspaceClearHighlighted = highlighted;
+    [self kb_refreshBackspaceClearLabelColors];
+}
+
+- (void)kb_refreshBackspaceClearLabelColors {
+    UILabel *label = self.backspaceClearLabel;
+    label.textColor = [KBSkinManager shared].current.keyTextColor ?: UIColor.blackColor;
+    label.backgroundColor = self.backspaceClearHighlighted
+                            ? [self kb_backspaceClearLabelHighlightedColor]
+                            : [self kb_backspaceClearLabelNormalColor];
+}
+
+- (UIColor *)kb_backspaceClearLabelNormalColor {
+    KBSkinTheme *t = [KBSkinManager shared].current;
+    return t.keyHighlightBackground ?: [UIColor colorWithWhite:0.9 alpha:1.0];
+}
+
+- (UIColor *)kb_backspaceClearLabelHighlightedColor {
+    KBSkinTheme *t = [KBSkinManager shared].current;
+    return t.accentColor ?: t.keyHighlightBackground ?: [UIColor colorWithWhite:0.8 alpha:1.0];
+}
+
+- (UILabel *)backspaceClearLabel {
+    if (!_backspaceClearLabel) {
+        UILabel *label = [[UILabel alloc] initWithFrame:CGRectZero];
+        label.text = @"立刻清空";
+        label.textAlignment = NSTextAlignmentCenter;
+        label.font = [UIFont systemFontOfSize:12 weight:UIFontWeightSemibold];
+        label.textColor = [KBSkinManager shared].current.keyTextColor ?: UIColor.blackColor;
+        label.backgroundColor = [self kb_backspaceClearLabelNormalColor];
+        label.layer.cornerRadius = kKBBackspaceClearLabelCornerRadius;
+        label.layer.masksToBounds = YES;
+        label.hidden = YES;
+        label.userInteractionEnabled = NO;
+        _backspaceClearLabel = label;
+    }
+    return _backspaceClearLabel;
+}
+
+- (void)kb_clearAllInput {
+    UIInputViewController *ivc = KBFindInputViewController(self);
+    if (!ivc) { return; }
+    id<UITextDocumentProxy> proxy = ivc.textDocumentProxy;
+    NSInteger guard = 0; // 上限保护，避免极端情况下长时间阻塞
+    while (guard < 10000) {
+        NSString *before = proxy.documentContextBeforeInput ?: @"";
+        NSInteger count = before.length;
+        if (count <= 0) { break; }
+        for (NSInteger i = 0; i < count; i++) {
+            [proxy deleteBackward];
+        }
+        guard += count;
+    }
+}
+
+#pragma mark - Layout
+
+- (void)layoutSubviews {
+    [super layoutSubviews];
+    if (self.backspaceClearLabel && !self.backspaceClearLabel.hidden) {
+        [self kb_updateBackspaceClearLabelFrame];
+    }
+}
+
 #pragma mark - Lazy
 
 - (UIView *)row1 { if (!_row1) _row1 = [UIView new]; return _row1; }