From e22d51947ab75d909c14eab15d562ed4cdc3e7ec Mon Sep 17 00:00:00 2001
From: trafficlunar <hello@trafficlunar.net>
Date: Sat, 25 Jan 2025 23:15:32 +0000
Subject: [PATCH] feat: center canvas on image open

---
 src/components/dialogs/OpenImage.tsx | 15 +++++++++++++--
 src/context/Canvas.tsx               | 27 ++++++++++++++++++++++++++-
 2 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/src/components/dialogs/OpenImage.tsx b/src/components/dialogs/OpenImage.tsx
index 1f73d6d..0eae14f 100644
--- a/src/components/dialogs/OpenImage.tsx
+++ b/src/components/dialogs/OpenImage.tsx
@@ -24,7 +24,7 @@ import VersionCombobox from "../VersionCombobox";
 import { findBlockFromRgb } from "@/utils/findBlockFromRgb";
 
 function OpenImage({ close }: DialogProps) {
-	const { version, setVersion, setBlocks } = useContext(CanvasContext);
+	const { version, setBlocks, setVersion, centerCanvas } = useContext(CanvasContext);
 	const { setLoading } = useContext(LoadingContext);
 
 	const { acceptedFiles, getRootProps, getInputProps } = useDropzone({
@@ -52,6 +52,8 @@ function OpenImage({ close }: DialogProps) {
 		falling: false,
 	});
 
+	const [isFinished, setIsFinished] = useState(false);
+
 	useEffect(() => {
 		if (acceptedFiles[0]) {
 			const img = new Image();
@@ -96,6 +98,7 @@ function OpenImage({ close }: DialogProps) {
 
 	const onSubmit = async () => {
 		if (image) {
+			setIsFinished(false);
 			setLoading(true);
 			// Wait for loading indicator to appear
 			await new Promise((resolve) => setTimeout(resolve, 100));
@@ -131,10 +134,18 @@ function OpenImage({ close }: DialogProps) {
 			}
 
 			setLoading(false);
-			close();
+			setIsFinished(true);
 		}
 	};
 
+	useEffect(() => {
+		if (!isFinished) return;
+		centerCanvas();
+		close();
+
+		return () => setIsFinished(false);
+	}, [isFinished, centerCanvas, close]);
+
 	useEffect(() => {
 		Object.keys(blockTypeCheckboxesChecked).forEach((property) => {
 			const blocksWithProperty = Object.entries(blockData)
diff --git a/src/context/Canvas.tsx b/src/context/Canvas.tsx
index c9e112e..54af207 100644
--- a/src/context/Canvas.tsx
+++ b/src/context/Canvas.tsx
@@ -14,6 +14,7 @@ interface Context {
 	setCoords: React.Dispatch<React.SetStateAction<Position>>;
 	setScale: React.Dispatch<React.SetStateAction<number>>;
 	setVersion: React.Dispatch<React.SetStateAction<number>>;
+	centerCanvas: () => void;
 }
 
 interface Props {
@@ -29,6 +30,7 @@ export const CanvasProvider = ({ children }: Props) => {
 	const [scale, setScale] = useState(1);
 	const [version, setVersion] = useState(1214);
 
+	// Get the farthest away blocks in each direction
 	const canvasSize = useMemo(() => {
 		let minX = Infinity,
 			maxX = -Infinity;
@@ -50,9 +52,32 @@ export const CanvasProvider = ({ children }: Props) => {
 		};
 	}, [blocks]);
 
+	const centerCanvas = () => {
+		// Margin of 8 blocks on each side
+		const margin = 8 * 16;
+
+		// Calculate the total width and height of the blocks, including margin
+		const blocksWidth = (canvasSize.maxX - canvasSize.minX) * 16 + margin * 2;
+		const blocksHeight = (canvasSize.maxY - canvasSize.minY) * 16 + margin * 2;
+
+		// Calculate the scale to fit the blocks (with margin) within the stage
+		const scaleX = stageSize.width / blocksWidth;
+		const scaleY = stageSize.height / blocksHeight;
+
+		// Use the smaller scale to fit the blocks inside the entire screen
+		const newScale = Math.min(scaleX, scaleY);
+
+		// Calculate the coordinates to center the blocks in the middle of the stage
+		const newX = stageSize.width / 2 - ((blocksWidth - margin * 2) * newScale) / 2 - canvasSize.minX * 16 * newScale;
+		const newY = stageSize.height / 2 - ((blocksHeight - margin * 2) * newScale) / 2 - canvasSize.minY * 16 * newScale;
+
+		setScale(newScale);
+		setCoords({ x: newX, y: newY });
+	};
+
 	return (
 		<CanvasContext.Provider
-			value={{ stageSize, canvasSize, blocks, coords, scale, version, setStageSize, setBlocks, setCoords, setScale, setVersion }}
+			value={{ stageSize, canvasSize, blocks, coords, scale, version, setStageSize, setBlocks, setCoords, setScale, setVersion, centerCanvas }}
 		>
 			{children}
 		</CanvasContext.Provider>