From 8a447a7555a9484aa0451203fce6e870f10e3051 Mon Sep 17 00:00:00 2001
From: Aspen Schneider <rendezvous71@outlook.com>
Date: Tue, 5 May 2026 12:08:21 +0900
Subject: [PATCH 1/6] BView resize event.

---
 Sources/Blusher/Core/Color.swift         |  4 +++
 Sources/Blusher/GUI/BView.swift          | 31 +++++++++++++++++++++++-
 Sources/Blusher/GUI/Window/BWindow.swift | 19 ++++++++++++---
 3 files changed, 50 insertions(+), 4 deletions(-)

diff --git a/Sources/Blusher/Core/Color.swift b/Sources/Blusher/Core/Color.swift
index 78692d5..5513796 100644
--- a/Sources/Blusher/Core/Color.swift
+++ b/Sources/Blusher/Core/Color.swift
@@ -31,4 +31,8 @@ public extension Color {
     static var red: Color {
         Color(r: 1.0, g: 0.0, b: 0.0, a: 1.0)
     }
+
+    static var transparent: Color {
+        Color(r: 0.0, g: 0.0, b: 0.0, a: 0.0)
+    }
 }
diff --git a/Sources/Blusher/GUI/BView.swift b/Sources/Blusher/GUI/BView.swift
index 62ce4ab..3032305 100644
--- a/Sources/Blusher/GUI/BView.swift
+++ b/Sources/Blusher/GUI/BView.swift
@@ -24,6 +24,7 @@ open class BView {
     private var _pointerPressEventListener: EventListener!
     private var _pointerReleaseEventListener: EventListener!
     private var _pointerClickEventListener: EventListener!
+    private var _resizeEventListener: EventListener!
 
     internal var _pointerEnterHandler: ((PointerEvent) -> Void)? = nil
     internal var _pointerLeaveHandler: ((PointerEvent) -> Void)? = nil
@@ -31,6 +32,7 @@ open class BView {
     internal var _pointerPressHandler: ((PointerEvent) -> Void)? = nil
     internal var _pointerReleaseHandler: ((PointerEvent) -> Void)? = nil
     internal var _pointerClickHandler: ((PointerEvent) -> Void)? = nil
+    internal var _resizeHandler: ((ResizeEvent) -> Void)? = nil
 
     internal var cPointer: OpaquePointer? {
         _sbView
@@ -73,7 +75,9 @@ open class BView {
             return _color
         }
         set(newValue) {
-            if _color == newValue {
+            // TODO: Optimization.
+            if newValue == .transparent {
+            } else if _color == newValue {
                 return
             }
 
@@ -358,6 +362,17 @@ open class BView {
         } as EventListener
         sb_view_add_event_listener(_sbView, SB_EVENT_TYPE_POINTER_CLICK,
             _pointerClickEventListener, userData)
+
+        // Resize event.
+        _resizeEventListener = { sbEvent, userData in
+            if let userData = userData {
+                let instance = Unmanaged<BView>.fromOpaque(userData).takeUnretainedValue()
+
+                instance.callResizeEvent(sbEvent)
+            }
+        } as EventListener
+        sb_view_add_event_listener(_sbView, SB_EVENT_TYPE_RESIZE,
+            _resizeEventListener, userData)
     }
 
     private func callPointerEnterEvent(_ sbEvent: UnsafeMutablePointer<sb_event_t>?) {
@@ -456,6 +471,16 @@ open class BView {
         pointerClickEvent(event)
     }
 
+    private func callResizeEvent(_ sbEvent: UnsafeMutablePointer<sb_event_t>?) {
+        // TODO: Real values.
+        print("TODO: BView.resizeEvent values not set.")
+        let event = ResizeEvent(
+            oldSize: Size(width: 0.0, height: 0.0),
+            size: Size(width: 0.0, height: 0.0)
+        )
+        resizeEvent(event)
+    }
+
     open func pointerEnterEvent(_ event: PointerEvent) {
         ToplevelStorage._uiSurface = self._surface
         _pointerEnterHandler?(event)
@@ -488,4 +513,8 @@ open class BView {
         _pointerClickHandler?(event)
         ToplevelStorage._uiSurface = nil
     }
+
+    open func resizeEvent(_ event: ResizeEvent) {
+        _resizeHandler?(event)
+    }
 }
diff --git a/Sources/Blusher/GUI/Window/BWindow.swift b/Sources/Blusher/GUI/Window/BWindow.swift
index 27881a8..64f0729 100644
--- a/Sources/Blusher/GUI/Window/BWindow.swift
+++ b/Sources/Blusher/GUI/Window/BWindow.swift
@@ -247,7 +247,7 @@ public class BWindowResize: BView {
 
             self.cursorShape = _cursorShape
 
-            self.color = Color(r: 1.0, g: 0.0, b: 0.0, a: 0.5)
+            self.color = .transparent
         }
 
         public override func pointerPressEvent(_ event: PointerEvent) {
@@ -275,7 +275,7 @@ public class BWindowResize: BView {
 
         super.init(surface: window, geometry: Rect(x: 0.0, y: 0.0, width: 1.0, height: 1.0))
 
-        self.color = Color(r: 0.0, g: 1.0, b: 0.0, a: 0.5)
+        self.color = .transparent
 
         // Create edges.
         _topLeft = Edge(at: .topLeft, in: self)
@@ -334,9 +334,22 @@ public class BWindowShadow: BView {
         set { return }
     }
 
+    private var _shadowInner: BView!
+
     init(_ window: BWindow) {
         super.init(surface: window, geometry: Rect(x: 0.0, y: 0.0, width: 1.0, height: 1.0))
 
-        self.color = Color(r: 0.0, g: 0.0, b: 0.0, a: 0.5)
+        _shadowInner = BView(
+            parent: self,
+            geometry: Rect(
+                x: 20.0, y: 20.0,
+                width: Float(window.surfaceSize.width) - 20.0,
+                height: Float(window.surfaceSize.height) - 20.0
+            )
+        )
+        _shadowInner.color = Color(r: 0.0, g: 0.0, b: 0.0, a: 0.5)
+        _shadowInner.addFilter(Blur(radius: 5.0))
+
+        self.color = .transparent
     }
 }

From 4643e99129b56ba722e5e37473651694abe418a7 Mon Sep 17 00:00:00 2001
From: Aspen Schneider <rendezvous71@outlook.com>
Date: Tue, 5 May 2026 14:10:00 +0900
Subject: [PATCH 2/6] Add resize event for view.

---
 Sources/Blusher/Core/Events/Event.swift  | 39 ++++++++++++++++++++++++
 Sources/Blusher/GUI/BView.swift          |  3 ++
 Sources/Blusher/GUI/Window/BWindow.swift | 10 ++++--
 3 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/Sources/Blusher/Core/Events/Event.swift b/Sources/Blusher/Core/Events/Event.swift
index ddbe47f..2464c69 100644
--- a/Sources/Blusher/Core/Events/Event.swift
+++ b/Sources/Blusher/Core/Events/Event.swift
@@ -40,3 +40,42 @@ public class Event {
         self.type = type
     }
 }
+
+public struct EventHandler<T> {
+    public final class Handler {
+        let closure: (T) -> Void
+
+        public init(_ closure: @escaping (T) -> Void) {
+            self.closure = closure
+        }
+    }
+
+    internal var handlers: [Handler] = []
+
+    public func invoke(_ event: T) {
+        self.handlers.forEach {
+            $0.closure(event)
+        }
+    }
+}
+
+public func += <T>(_ lhs: inout EventHandler<T>?, _ rhs: EventHandler<T>.Handler) {
+    if lhs == nil {
+        lhs = EventHandler()
+    }
+    lhs!.handlers.append(rhs)
+}
+
+public func += <T>(_ lhs: inout EventHandler<T>?, _ rhs: @escaping (T) -> Void) {
+    if lhs == nil {
+        lhs = EventHandler()
+    }
+    lhs!.handlers.append(EventHandler<T>.Handler(rhs))
+}
+
+public func -= <T>(_ lhs: inout EventHandler<T>?, _ rhs: EventHandler<T>.Handler) {
+    lhs?.handlers.removeAll { $0 === rhs }
+    if lhs?.handlers.count == 0 {
+        lhs = nil
+    }
+}
diff --git a/Sources/Blusher/GUI/BView.swift b/Sources/Blusher/GUI/BView.swift
index 3032305..b54d875 100644
--- a/Sources/Blusher/GUI/BView.swift
+++ b/Sources/Blusher/GUI/BView.swift
@@ -34,6 +34,8 @@ open class BView {
     internal var _pointerClickHandler: ((PointerEvent) -> Void)? = nil
     internal var _resizeHandler: ((ResizeEvent) -> Void)? = nil
 
+    public var onResize: EventHandler<ResizeEvent>? = nil
+
     internal var cPointer: OpaquePointer? {
         _sbView
     }
@@ -516,5 +518,6 @@ open class BView {
 
     open func resizeEvent(_ event: ResizeEvent) {
         _resizeHandler?(event)
+        self.onResize?.invoke(event)
     }
 }
diff --git a/Sources/Blusher/GUI/Window/BWindow.swift b/Sources/Blusher/GUI/Window/BWindow.swift
index 64f0729..df53fd9 100644
--- a/Sources/Blusher/GUI/Window/BWindow.swift
+++ b/Sources/Blusher/GUI/Window/BWindow.swift
@@ -343,12 +343,18 @@ public class BWindowShadow: BView {
             parent: self,
             geometry: Rect(
                 x: 20.0, y: 20.0,
-                width: Float(window.surfaceSize.width) - 20.0,
-                height: Float(window.surfaceSize.height) - 20.0
+                width: Float(window.surfaceSize.width) - 40.0,
+                height: Float(window.surfaceSize.height) - 40.0
             )
         )
         _shadowInner.color = Color(r: 0.0, g: 0.0, b: 0.0, a: 0.5)
         _shadowInner.addFilter(Blur(radius: 5.0))
+        self.onResize += { [weak self] event in
+            self?._shadowInner.size = Size(
+                width: Float(window.surfaceSize.width) - 40.0,
+                height: Float(window.surfaceSize.height) - 40.0
+            )
+        }
 
         self.color = .transparent
     }

From 8b44216476854f878edecf82b20efe82227acb88 Mon Sep 17 00:00:00 2001
From: Aspen Schneider <rendezvous71@outlook.com>
Date: Thu, 28 May 2026 15:46:20 +0900
Subject: [PATCH 3/6] Sync with Swingby, `Rect.pos` to `Rect.position`.

---
 Sources/Blusher/Core/Rect.swift    | 16 ++++++++--------
 Sources/Blusher/GUI/BSurface.swift | 14 +++++++++-----
 Sources/Blusher/GUI/BView.swift    | 14 +++++++-------
 3 files changed, 24 insertions(+), 20 deletions(-)

diff --git a/Sources/Blusher/Core/Rect.swift b/Sources/Blusher/Core/Rect.swift
index 4e86286..4e63c00 100644
--- a/Sources/Blusher/Core/Rect.swift
+++ b/Sources/Blusher/Core/Rect.swift
@@ -1,23 +1,23 @@
 public struct Rect: Equatable {
-    public var pos: Point = Point(x: 0.0, y: 0.0)
+    public var position: Point = Point(x: 0.0, y: 0.0)
     public var size: Size = Size(width: 0.0, height: 0.0)
 
     public init(x: Float, y: Float, width: Float, height: Float) {
-        pos.x = x
-        pos.y = y
+        position.x = x
+        position.y = y
         size.width = width
         size.height = height
     }
 
     public var x: Float {
         get {
-            return pos.x
+            return position.x
         }
     }
 
     public var y: Float {
         get {
-            return pos.y
+            return position.y
         }
     }
 
@@ -41,12 +41,12 @@ extension Rect: CustomStringConvertible {
 }
 
 public struct RectI: Equatable {
-    public var pos: PointI = PointI(x: 0, y: 0)
+    public var position: PointI = PointI(x: 0, y: 0)
     public var size: SizeI = SizeI(width: 0, height: 0)
 
     public init(x: Int64, y: Int64, width: UInt64, height: UInt64) {
-        pos.x = x
-        pos.y = y
+        position.x = x
+        position.y = y
         size.width = width
         size.height = height
     }
diff --git a/Sources/Blusher/GUI/BSurface.swift b/Sources/Blusher/GUI/BSurface.swift
index 208310f..f169d22 100644
--- a/Sources/Blusher/GUI/BSurface.swift
+++ b/Sources/Blusher/GUI/BSurface.swift
@@ -99,7 +99,9 @@ public class BSurface {
 
             if _visible {
                 var sbRect = sb_rect_t(
-                    pos: sb_point_t(x: Float(newValue.pos.x), y: Float(newValue.pos.y)),
+                    position: sb_point_t(
+                        x: Float(newValue.position.x), y: Float(newValue.position.y)
+                    ),
                     size: sb_size_t(width: Float(newValue.size.width), height: Float(newValue.size.height))
                 )
 
@@ -117,7 +119,9 @@ public class BSurface {
         }
         set {
             var sbRect = sb_rect_t(
-                pos: sb_point_t(x: Float(newValue.pos.x), y: Float(newValue.pos.y)),
+                position: sb_point_t(
+                    x: Float(newValue.position.x), y: Float(newValue.position.y)
+                ),
                 size: sb_size_t(width: Float(newValue.size.width), height: Float(newValue.size.height))
             )
 
@@ -198,9 +202,9 @@ public class BSurface {
         // wmGeometry must set after .show() called.
         if _visible && _wmGeometry != nil {
             var sbRect = sb_rect_t(
-                pos: sb_point_t(
-                    x: Float(_wmGeometry!.pos.x),
-                    y: Float(_wmGeometry!.pos.y)
+                position: sb_point_t(
+                    x: Float(_wmGeometry!.position.x),
+                    y: Float(_wmGeometry!.position.y)
                 ),
                 size: sb_size_t(
                     width: Float(_wmGeometry!.size.width),
diff --git a/Sources/Blusher/GUI/BView.swift b/Sources/Blusher/GUI/BView.swift
index b54d875..488a944 100644
--- a/Sources/Blusher/GUI/BView.swift
+++ b/Sources/Blusher/GUI/BView.swift
@@ -116,8 +116,8 @@ open class BView {
     public var geometry: Rect {
         get {
             let sbRect = sb_view_geometry(_sbView)
-            let x = sbRect!.pointee.pos.x
-            let y = sbRect!.pointee.pos.y
+            let x = sbRect!.pointee.position.x
+            let y = sbRect!.pointee.position.y
             let width = sbRect!.pointee.size.width
             let height = sbRect!.pointee.size.height
 
@@ -131,7 +131,7 @@ open class BView {
             _geometry = newValue
 
             var sbRect = sb_rect_t(
-                pos: sb_point_t(x: newValue.pos.x, y: newValue.pos.y),
+                position: sb_point_t(x: newValue.position.x, y: newValue.position.y),
                 size: sb_size_t(width: newValue.size.width, height: newValue.size.height)
             )
 
@@ -145,7 +145,7 @@ open class BView {
 
     public var position: Point {
         get {
-            return Point(x: geometry.pos.x, y: geometry.pos.y)
+            return Point(x: geometry.position.x, y: geometry.position.y)
         }
         set {
             let geo = Rect(
@@ -162,7 +162,7 @@ open class BView {
         }
         set(newValue) {
             let geo = Rect(
-                x: geometry.pos.x, y: geometry.pos.y,
+                x: geometry.position.x, y: geometry.position.y,
                 width: newValue.width, height: newValue.height
             )
             geometry = geo
@@ -218,7 +218,7 @@ open class BView {
     public init(parent: BView, geometry: Rect) {
         let sbParent = parent._sbView
         var sbRect = sb_rect_t(
-            pos: sb_point_t(x: geometry.x, y: geometry.y),
+            position: sb_point_t(x: geometry.x, y: geometry.y),
             size: sb_size_t(width: geometry.width, height: geometry.height)
         )
 
@@ -237,7 +237,7 @@ open class BView {
 
     public init(surface: BSurface, geometry: Rect) {
         var sbRect = sb_rect_t(
-            pos: sb_point_t(x: geometry.x, y: geometry.y),
+            position: sb_point_t(x: geometry.x, y: geometry.y),
             size: sb_size_t(width: geometry.width, height: geometry.height)
         )
 

From 3736da2d10c05e6907595a422a4a7aa7c0117313 Mon Sep 17 00:00:00 2001
From: Aspen Schneider <rendezvous71@outlook.com>
Date: Fri, 29 May 2026 12:09:37 +0900
Subject: [PATCH 4/6] Canvas view test.

---
 Sources/Blusher/Core/Canvas.swift             | 51 +++++++++++++++++++
 Sources/Blusher/Core/Events/Event.swift       |  1 +
 Sources/Blusher/Core/Paint.swift              | 10 ++++
 Sources/Blusher/GUI/BView.swift               | 34 +++++++++++++
 Sources/Blusher/GUI/Window/BWindow.swift      | 27 ++++++++++
 .../Sources/Example/Example.swift             |  1 -
 6 files changed, 123 insertions(+), 1 deletion(-)
 create mode 100644 Sources/Blusher/Core/Canvas.swift
 create mode 100644 Sources/Blusher/Core/Paint.swift

diff --git a/Sources/Blusher/Core/Canvas.swift b/Sources/Blusher/Core/Canvas.swift
new file mode 100644
index 0000000..25450fb
--- /dev/null
+++ b/Sources/Blusher/Core/Canvas.swift
@@ -0,0 +1,51 @@
+@_implementationOnly import Swingby
+
+func colorToSbColor(_ color: Color) -> sb_color_t {
+    let sb_color_t = sb_color_t(r: color.r, g: color.g, b: color.b, a: color.a)
+
+    return sb_color_t
+}
+
+func paintToSbPaint(_ paint: Paint) -> sb_paint_t {
+    let sbPaint = sb_paint_t(
+        fill_color: colorToSbColor(paint.fillColor),
+        stroke_color: colorToSbColor(paint.strokeColor),
+        stroke_width: paint.strokeWidth
+    )
+
+    return sbPaint
+}
+
+public class Canvas {
+    private var _sbCanvas: OpaquePointer? = nil
+
+    internal init(_ sbCanvas: OpaquePointer) {
+        _sbCanvas = sbCanvas
+    }
+
+    public func drawRect(_ rect: Rect, _ paint: Paint) {
+        var sbRect = sb_rect_t(
+            position: sb_point_t(x: rect.x, y: rect.y),
+            size: sb_size_t(width: rect.width, height: rect.height)
+        )
+        var sbPaint = paintToSbPaint(paint)
+
+        if let sbCanvas = _sbCanvas {
+            sb_canvas_draw_rect(sbCanvas, &sbRect, &sbPaint)
+        }
+    }
+
+    public func drawLine(_ p1: Point, _ p2: Point, _ paint: Paint) {
+        if let sbCanvas = _sbCanvas {
+            var sbP1 = sb_point_t(x: p1.x, y: p1.y)
+            var sbP2 = sb_point_t(x: p2.x, y: p2.y)
+            var sbPaint = paintToSbPaint(paint)
+
+            sb_canvas_draw_line(sbCanvas, &sbP1, &sbP2, &sbPaint)
+        }
+    }
+
+    public func drawLine(_ x1: Float, _ y1: Float, _ x2: Float, _ y2: Float, _ paint: Paint) {
+        self.drawLine(Point(x: x1, y: y1), Point(x: x2, y: y2), paint)
+    }
+}
diff --git a/Sources/Blusher/Core/Events/Event.swift b/Sources/Blusher/Core/Events/Event.swift
index 2464c69..c48c00f 100644
--- a/Sources/Blusher/Core/Events/Event.swift
+++ b/Sources/Blusher/Core/Events/Event.swift
@@ -8,6 +8,7 @@ public enum EventType {
     case pointerPress
     case pointerRelease
     case pointerClick
+    case paint
     case resize
     case preferredScale
 }
diff --git a/Sources/Blusher/Core/Paint.swift b/Sources/Blusher/Core/Paint.swift
new file mode 100644
index 0000000..c3e4bb1
--- /dev/null
+++ b/Sources/Blusher/Core/Paint.swift
@@ -0,0 +1,10 @@
+@_implementationOnly import Swingby
+
+public struct Paint {
+    public var fillColor: Color = .transparent
+    public var strokeColor: Color = .black
+    public var strokeWidth: Float = 0.0
+
+    public init() {
+    }
+}
diff --git a/Sources/Blusher/GUI/BView.swift b/Sources/Blusher/GUI/BView.swift
index 488a944..37976d8 100644
--- a/Sources/Blusher/GUI/BView.swift
+++ b/Sources/Blusher/GUI/BView.swift
@@ -3,6 +3,8 @@
 public enum ViewRenderType {
     case singleColor
     case image
+    case text
+    case canvas
 }
 
 open class BView {
@@ -25,6 +27,7 @@ open class BView {
     private var _pointerReleaseEventListener: EventListener!
     private var _pointerClickEventListener: EventListener!
     private var _resizeEventListener: EventListener!
+    private var _paintEventListener: EventListener!
 
     internal var _pointerEnterHandler: ((PointerEvent) -> Void)? = nil
     internal var _pointerLeaveHandler: ((PointerEvent) -> Void)? = nil
@@ -33,6 +36,7 @@ open class BView {
     internal var _pointerReleaseHandler: ((PointerEvent) -> Void)? = nil
     internal var _pointerClickHandler: ((PointerEvent) -> Void)? = nil
     internal var _resizeHandler: ((ResizeEvent) -> Void)? = nil
+    internal var _paintHandler: ((Event) -> Void)? = nil
 
     public var onResize: EventHandler<ResizeEvent>? = nil
 
@@ -67,6 +71,8 @@ open class BView {
             let sbType = switch _renderType {
                 case .singleColor: SB_VIEW_RENDER_TYPE_SINGLE_COLOR
                 case .image: SB_VIEW_RENDER_TYPE_IMAGE
+                case .text: SB_VIEW_RENDER_TYPE_GLYPHS
+                case .canvas: SB_VIEW_RENDER_TYPE_CANVAS
             }
             sb_view_set_render_type(_sbView, sbType)
         }
@@ -113,6 +119,14 @@ open class BView {
         }
     }
 
+    public var canvas: Canvas? {
+        if let sbCanvas = sb_view_canvas(_sbView) {
+            let canvas = Canvas(sbCanvas)
+            return canvas
+        }
+        return nil
+    }
+
     public var geometry: Rect {
         get {
             let sbRect = sb_view_geometry(_sbView)
@@ -375,6 +389,17 @@ open class BView {
         } as EventListener
         sb_view_add_event_listener(_sbView, SB_EVENT_TYPE_RESIZE,
             _resizeEventListener, userData)
+
+        // Paint event.
+        _paintEventListener = { sbEvent, userData in
+            if let userData = userData {
+                let instance = Unmanaged<BView>.fromOpaque(userData).takeUnretainedValue()
+
+                instance.callPaintEvent(sbEvent)
+            }
+        }
+        sb_view_add_event_listener(_sbView, SB_EVENT_TYPE_PAINT,
+            _paintEventListener, userData)
     }
 
     private func callPointerEnterEvent(_ sbEvent: UnsafeMutablePointer<sb_event_t>?) {
@@ -483,6 +508,11 @@ open class BView {
         resizeEvent(event)
     }
 
+    private func callPaintEvent(_ sbEvent: UnsafeMutablePointer<sb_event_t>?) {
+        let event = Event(of: .paint)
+        paintEvent(event)
+    }
+
     open func pointerEnterEvent(_ event: PointerEvent) {
         ToplevelStorage._uiSurface = self._surface
         _pointerEnterHandler?(event)
@@ -520,4 +550,8 @@ open class BView {
         _resizeHandler?(event)
         self.onResize?.invoke(event)
     }
+
+    open func paintEvent(_ event: Event) {
+        _paintHandler?(event)
+    }
 }
diff --git a/Sources/Blusher/GUI/Window/BWindow.swift b/Sources/Blusher/GUI/Window/BWindow.swift
index df53fd9..6660fc8 100644
--- a/Sources/Blusher/GUI/Window/BWindow.swift
+++ b/Sources/Blusher/GUI/Window/BWindow.swift
@@ -167,6 +167,29 @@ public class BTitleBar: BView {
         }
     }
 
+    public class Caption: BView {
+        init(_ titleBar: BTitleBar) {
+            let rect = Rect(x: 100.0, y: 0.0, width: 100.0, height: BTitleBar.thickness)
+            super.init(parent: titleBar, geometry: rect)
+
+            self.renderType = .canvas
+        }
+
+        public override func paintEvent(_ event: Event) {
+            var paint = Paint()
+            paint.strokeWidth = 2.0
+            paint.strokeColor = .black
+
+            self.canvas?.drawLine(
+                Point(x: 0.0, y: 10.0),
+                Point(x: 30.0, y: 10.0),
+                paint
+            )
+
+            super.paintEvent(event)
+        }
+    }
+
     public static var thickness: Float {
         30.0
     }
@@ -178,6 +201,8 @@ public class BTitleBar: BView {
     private var _minimizeButton: Button!
     private var _maximizeOrRestoreButton: Button!
 
+    private var _caption: Caption!
+
     init(_ window: BWindow) {
         _window = window
 
@@ -193,6 +218,8 @@ public class BTitleBar: BView {
         _minimizeButton.position = Point(x: 40.0, y: 3.0)
         _maximizeOrRestoreButton.position = Point(x: 70.0, y: 3.0)
 
+        _caption = Caption(self)
+
         self.color = Color(r: 0.5, g: 0.5, b: 0.5, a: 1.0)
         self.radius = Radius(topLeft: 8.0, topRight: 8.0, bottomRight: 0.0, bottomLeft: 0.0)
     }
diff --git a/examples/07-image-spm/Sources/Example/Example.swift b/examples/07-image-spm/Sources/Example/Example.swift
index d006c0a..3314131 100644
--- a/examples/07-image-spm/Sources/Example/Example.swift
+++ b/examples/07-image-spm/Sources/Example/Example.swift
@@ -38,4 +38,3 @@ public struct Program {
         let _ = app.exec()
     }
 }
-

From 73294bdf56ff9353fc595752a79ceafac1e2dad7 Mon Sep 17 00:00:00 2001
From: Aspen Schneider <rendezvous71@outlook.com>
Date: Sun, 31 May 2026 09:59:37 +0900
Subject: [PATCH 5/6] Temporary `Bytes` to `String` encode function.

The API will be change as soon as.
---
 Sources/Blusher/Core/Utilities/Bytes.swift | 18 ++++++++++++++++++
 Tests/blusherTests/blusherTests.swift      |  9 +++++++++
 Tests/blusherTests/valid-utf8.txt          |  1 +
 3 files changed, 28 insertions(+)
 create mode 100644 Tests/blusherTests/valid-utf8.txt

diff --git a/Sources/Blusher/Core/Utilities/Bytes.swift b/Sources/Blusher/Core/Utilities/Bytes.swift
index 94174cf..2b311c0 100644
--- a/Sources/Blusher/Core/Utilities/Bytes.swift
+++ b/Sources/Blusher/Core/Utilities/Bytes.swift
@@ -34,4 +34,22 @@ public class Bytes {
             _ptr?.deallocate()
         }
     }
+
+    public func decode(encoding: UTF8) -> String? {
+        var codec = encoding
+        var result = ""
+        result.reserveCapacity(Int(_len))
+
+        var iter = _ptr!.makeIterator()
+        while true {
+            switch codec.decode(&iter) {
+            case .scalarValue(let scalar):
+                result.unicodeScalars.append(scalar)
+            case .emptyInput:
+                return result
+            case .error:
+                return nil
+            }
+        }
+    }
 }
diff --git a/Tests/blusherTests/blusherTests.swift b/Tests/blusherTests/blusherTests.swift
index f045979..9905812 100644
--- a/Tests/blusherTests/blusherTests.swift
+++ b/Tests/blusherTests/blusherTests.swift
@@ -26,3 +26,12 @@ import Testing
 
     let _ = bytes
 }
+
+@Test func bytes() async throws {
+    let file = FileSystem.File.open("Tests/blusherTests/valid-utf8.txt", "rb")
+    let bytes = file.readAll()
+    file.close()
+
+    let decoded = bytes.decode(encoding: UTF8())
+    #expect(decoded == "こんにちは！\n")
+}
diff --git a/Tests/blusherTests/valid-utf8.txt b/Tests/blusherTests/valid-utf8.txt
new file mode 100644
index 0000000..adfd97b
--- /dev/null
+++ b/Tests/blusherTests/valid-utf8.txt
@@ -0,0 +1 @@
+こんにちは！

From 77d8d87a22457cb5ba95eaf018a7d94f1947473f Mon Sep 17 00:00:00 2001
From: Aspen Schneider <rendezvous71@outlook.com>
Date: Mon, 1 Jun 2026 17:17:39 +0900
Subject: [PATCH 6/6] Add `FileSystem.fileExists` method.

---
 .../Blusher/Core/Utilities/FileSystem.swift    | 18 ++++++++++++++++++
 Tests/blusherTests/blusherTests.swift          |  8 ++++++++
 2 files changed, 26 insertions(+)

diff --git a/Sources/Blusher/Core/Utilities/FileSystem.swift b/Sources/Blusher/Core/Utilities/FileSystem.swift
index df43f75..c6aa794 100644
--- a/Sources/Blusher/Core/Utilities/FileSystem.swift
+++ b/Sources/Blusher/Core/Utilities/FileSystem.swift
@@ -1,3 +1,7 @@
+//================
+// C Standards
+//================
+
 @_silgen_name("fopen")
 func fopen(_: UnsafePointer<CChar>, _: UnsafePointer<CChar>) -> OpaquePointer
 
@@ -13,6 +17,14 @@ func fread(_: UnsafeMutableRawPointer, _: UInt, _: UInt, _: OpaquePointer) -> UI
 @_silgen_name("fclose")
 func fclose(_: OpaquePointer) -> Int32
 
+//===================
+// Unix Standards
+//===================
+
+@_silgen_name("access")
+func access(_: UnsafePointer<CChar>, _: Int32) -> Int32
+
+
 public enum FileSystem {
     public class File {
         private var _filePtr: OpaquePointer? = nil
@@ -62,4 +74,10 @@ public enum FileSystem {
             }
         }
     }
+
+    public static func fileExists(atPath path: String) -> Bool {
+        path.withCString {
+            return access($0, 0 /* F_OK */) == 0 ? true : false
+        }
+    }
 }
diff --git a/Tests/blusherTests/blusherTests.swift b/Tests/blusherTests/blusherTests.swift
index 9905812..d994bff 100644
--- a/Tests/blusherTests/blusherTests.swift
+++ b/Tests/blusherTests/blusherTests.swift
@@ -20,6 +20,14 @@ import Testing
 }
 
 @Test func fileSystem() async throws {
+    // Exists.
+    let here = FileSystem.fileExists(atPath: "/NO.txt")
+    #expect(here == false)
+
+    let there = FileSystem.fileExists(atPath: "Package.swift")
+    #expect(there == true)
+
+    // Open.
     let file = FileSystem.File.open("Package.swift", "rb")
     let bytes = file.readAll()
     file.close()