From e6eeb88c14825295648e5e6af001155289c10351 Mon Sep 17 00:00:00 2001
From: miteruzo <miteruzo@naver.com>
Date: Sun, 10 Aug 2025 17:19:56 +0900
Subject: [PATCH] #3

---
 .../src/components/threads/ThreadCanvas.tsx   | 60 +++++++++++--------
 1 file changed, 35 insertions(+), 25 deletions(-)

diff --git a/frontend/src/components/threads/ThreadCanvas.tsx b/frontend/src/components/threads/ThreadCanvas.tsx
index d86c69f..ff39086 100644
--- a/frontend/src/components/threads/ThreadCanvas.tsx
+++ b/frontend/src/components/threads/ThreadCanvas.tsx
@@ -116,6 +116,7 @@ const isLayer = (obj: unknown): obj is Layer => (
 export default () => {
   const drawingRef = useRef (false)
   const fileInputRef = useRef<HTMLInputElement> (null)
+  const layersRef = useRef<Record<string, Konva.Layer>> ({ })
   const stageRef = useRef<Konva.Stage | null> (null)
 
   const [activeLayerId, setActiveLayerId] = useState<string | null> (null)
@@ -125,6 +126,7 @@ export default () => {
   const [layers, setLayers] = useState<Layer[]> ([])
   const [mode, setMode] = useState<Mode> (Mode.Pen)
   const [pointSize, setPointSize] = useState (3)
+  const [singleLayer, setSingleLayer] = useState (false)
   const [stageHeight, setStageHeight] = useState (480)
   const [stageWidth, setStageWidth] = useState (480)
 
@@ -210,37 +212,31 @@ export default () => {
       fileInputRef.current.value = ''
   }
 
-  const handlePaint = async () => {
+  const handlePaint = (ev: Konva.KonvaEventObject<PointerEvent | MouseEvent | TouchEvent>) => {
     const layer = activeLayer
-    if (!(layer) || !(stageRef.current))
+    if (!(layer) || !(layersRef.current?.[layer.id]))
       return
 
-    const stage = stageRef.current
-    const pos = stage.getPointerPosition ()
+    const pos = ev.target.getStage ()?.getPointerPosition ()
     if (!(pos))
       return
 
-    const dataURL = stage.toDataURL ({ mimeType: 'image/png', pixelRatio: 1 })
+    const stage = layersRef.current[layer.id]
+    if (!(stage))
+      return
 
-    const img = new window.Image
-    img.crossOrigin = 'anonymous'
-    await new Promise<void> (res => {
-      img.onload = () => res ()
-      img.src = dataURL
-    })
+    if (drawingRef.current)
+      return
+
+    drawingRef.current = true
 
-    const $off = document.createElement ('canvas')
-    $off.width = stageWidth
-    $off.height = stageHeight
-    const ctx = $off.getContext ('2d')
-    ctx!.drawImage (img, 0, 0, stageWidth, stageHeight)
+    const off = stage.toCanvas ({ pixelRatio: 1 })
+    const ctx = off.getContext ('2d')!
+    const imgData = ctx.getImageData (0, 0, off.width, off.height)
 
-    const imgData = ctx!.getImageData (0, 0, stageWidth, stageHeight)
     const [r, g, b, a] = hexToRgba (colour, 255)
     floodFill (imgData, Math.floor (pos.x), Math.floor (pos.y), { r, g, b, a })
-    ctx!.putImageData (imgData, 0, 0)
-
-    const nextSrc = $off.toDataURL ('image/png')
+    ctx.putImageData (imgData, 0, 0)
 
     updateActiveLayerHistory ([...layer.history, layer.lines])
     updateActiveLayerFuture ([])
@@ -251,7 +247,9 @@ export default () => {
 		{ mode:     Mode.Paint,
 		  points:   [pos.x, pos.y],
 		  stroke:   colour,
-		  imageSrc: nextSrc }] }) : l))
+		  imageSrc: off.toDataURL ('image/png') }] }) : l))
+
+    drawingRef.current = false
   }
 
   const updateActiveLayerLines = (lines: Line[]) => {
@@ -537,11 +535,19 @@ export default () => {
 	      追加
 	    </button>
 	  </div>
+
+	  <label>
+	    <input type="checkbox"
+		   checked={singleLayer}
+		   onChange={ev => setSingleLayer (ev.target.checked)} />
+	    レイアを分けて表示
+	  </label>
 	</div>
 
 	<div className="w-full flex items-center justify-center mb-16">
 	  <div className="border border-black dark:border-white">
-	    <Stage ref={node => {
+	    <Stage className="touch-none"
+		   ref={node => {
 		     stageRef.current = node
 		   }}
 		   width={stageWidth}
@@ -561,8 +567,11 @@ export default () => {
 		      listening={false} />
 	      </Layer>
 
-	      {layers.map (layer => (
-		  <Layer key={layer.id}>
+	      {layers.map (layer => (!(singleLayer) || layer.id === activeLayerId) && (
+		  <Layer key={layer.id} ref={node => {
+		    if (node)
+		      layersRef.current = { ...layersRef.current, [layer.id]: node }
+		  }}>
 		    {images[layer.id] && (
 			<Image image={images[layer.id]}
 			       x={0}
@@ -587,7 +596,8 @@ export default () => {
 							  : 'source-over'} />)
 		      case Mode.Paint:
 			return (
-			    <Image image={images[line.imageSrc]}
+			    <Image key={i}
+				   image={images[line.imageSrc]}
 				   x={0}
 				   y={0}
 				   scaleX={1}