2

CustomKeyboard/KeyboardViewController.m

@@ -729,6 +729,20 @@ static void KBSkinInstallNotificationCallback(CFNotificationCenterRef center,
 - (void)kb_applyTheme {
     KBSkinTheme *t = [KBSkinManager shared].current;
     UIImage *img = [[KBSkinManager shared] currentBackgroundImage];
+    if ([self kb_isDefaultKeyboardTheme:t]) {
+        CGSize size = self.bgImageView.bounds.size;
+        if (size.width <= 0 || size.height <= 0) {
+            [self.view layoutIfNeeded];
+            size = self.bgImageView.bounds.size;
+        }
+        if (size.width <= 0 || size.height <= 0) {
+            size = self.view.bounds.size;
+        }
+        if (size.width <= 0 || size.height <= 0) {
+            size = [UIScreen mainScreen].bounds.size;
+        }
+        img = [self kb_defaultGradientImageWithSize:size];
+    }
     NSLog(@"⌨️[Keyboard] apply theme id=%@ hasBg=%d", t.skinId, (img != nil));
     [self kb_logSkinDiagnosticsWithTheme:t backgroundImage:img];
     self.bgImageView.image = img;
@@ -752,6 +766,32 @@ static void KBSkinInstallNotificationCallback(CFNotificationCenterRef center,
     }
 }
 
+- (BOOL)kb_isDefaultKeyboardTheme:(KBSkinTheme *)theme {
+    NSString *skinId = theme.skinId ?: @"";
+    if (skinId.length == 0 || [skinId isEqualToString:@"default"]) {
+        return YES;
+    }
+    return [skinId isEqualToString:kKBDefaultSkinId];
+}
+
+- (UIImage *)kb_defaultGradientImageWithSize:(CGSize)size {
+    if (size.width <= 0 || size.height <= 0) { return nil; }
+    CAGradientLayer *layer = [CAGradientLayer layer];
+    layer.frame = CGRectMake(0, 0, size.width, size.height);
+    layer.startPoint = CGPointMake(0.5, 0.0);
+    layer.endPoint = CGPointMake(0.5, 1.0);
+    layer.colors = @[
+        (id)[UIColor colorWithHex:0xDEDFE4].CGColor,
+        (id)[UIColor colorWithHex:0xD1D3DB].CGColor
+    ];
+
+    UIGraphicsBeginImageContextWithOptions(size, YES, 0);
+    [layer renderInContext:UIGraphicsGetCurrentContext()];
+    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
+    UIGraphicsEndImageContext();
+    return image;
+}
+
 - (void)kb_logSkinDiagnosticsWithTheme:(KBSkinTheme *)theme
                        backgroundImage:(UIImage *)image {
 #if DEBUG