5 files changed, 158 insertions, 16 deletions
diff --git a/web/src/components/grid/cellAtCoord.ts b/web/src/components/grid/cellAtCoord.ts
new file mode 100644
index 0000000..dd594a4
--- /dev/null
+++ b/web/src/components/grid/cellAtCoord.ts
@@ -0,0 +1,40 @@
+import Coord from "../../math/Coord";
+import { CellRef } from "../../types";
+import { RenderedGrid, RenderedRow } from "./renderGrid";
+
+function rowAtCoord(grid: RenderedGrid, coord: Coord): RenderedRow | undefined {
+  if (coord.y <= grid.rect.topLeft.y) {
+    return grid.renderedRows[0];
+  }
+
+  if (coord.y >= grid.rect.bottomRight.y) {
+    return grid.renderedRows.at(-1);
+  }
+
+  return grid.renderedRows.find((row) =>
+    row.rect.verticallyContainsCoord(coord),
+  );
+}
+
+export default function cellAtCoord(
+  grid: RenderedGrid,
+  x: number,
+  y: number,
+): CellRef | undefined {
+  const coord = new Coord(x, y);
+  const row = rowAtCoord(grid, coord);
+
+  if (!row) return;
+
+  if (x <= row.rect.topLeft.x) {
+    return row.renderedCells[0]?.cellRef;
+  }
+
+  if (x >= row.rect.bottomRight.x) {
+    return row.renderedCells.at(-1)?.cellRef;
+  }
+
+  return row.renderedCells.find((cell) =>
+    cell.rect.horizontallyContainsCoord(coord),
+  )?.cellRef;
+}
diff --git a/web/src/components/grid/drawGrid.ts b/web/src/components/grid/drawGrid.ts
index 6284693..01240b5 100644
--- a/web/src/components/grid/drawGrid.ts
+++ b/web/src/components/grid/drawGrid.ts
@@ -1,16 +1,21 @@
-import { RenderedGrid } from "./renderGrid";
-import colors from "open-color";
+import colors from "tailwindcss/colors";
+import { PendingSelection, Selection } from "../../selection";
+import { CellRef } from "../../types";
+import { RenderedCell, RenderedGrid } from "./renderGrid";
 
-export default function drawGrid(
-  ctx: CanvasRenderingContext2D,
-  grid: RenderedGrid,
-) {
+function fillBackground(ctx: CanvasRenderingContext2D, grid: RenderedGrid) {
   ctx.clearRect(0, 0, grid.rect.width, grid.rect.height);
-
-  ctx.fillStyle = colors.gray[8];
+  ctx.fillStyle = colors.neutral[800];
   ctx.fillRect(0, 0, grid.rect.width, grid.rect.height);
+}
+
+function strokeGrid(ctx: CanvasRenderingContext2D, grid: RenderedGrid) {
+  ctx.strokeStyle = colors.neutral[700];
+  ctx.strokeRect(0.5, 0.5, grid.rect.width - 1, grid.rect.height - 1);
+}
 
-  ctx.strokeStyle = colors.gray[7];
+function strokeGridLines(ctx: CanvasRenderingContext2D, grid: RenderedGrid) {
+  ctx.strokeStyle = colors.neutral[700];
 
   grid.renderedRows.forEach((row, renderedRowIndex) => {
     const isLastRow = renderedRowIndex === grid.renderedRows.length - 1;
@@ -28,3 +33,75 @@ export default function drawGrid(
     });
   });
 }
+
+function getRenderedCell(
+  grid: RenderedGrid,
+  cellRef: CellRef,
+): RenderedCell | undefined {
+  const rowsPerPart = grid.renderedRows.length / grid.parts.length;
+  const renderedRowIndex = cellRef.partIndex * rowsPerPart + cellRef.rowIndex;
+  return grid.renderedRows[renderedRowIndex]?.renderedCells[cellRef.cellIndex];
+}
+
+function drawPendingSelection(
+  ctx: CanvasRenderingContext2D,
+  grid: RenderedGrid,
+  selection: PendingSelection,
+) {}
+
+function drawSelection(
+  ctx: CanvasRenderingContext2D,
+  grid: RenderedGrid,
+  selection: Selection,
+) {
+  if (selection.gridId !== grid.id) return;
+
+  const cell = getRenderedCell(grid, selection.activeCellRef);
+
+  if (!cell) return;
+
+  const isLastCell = cell.rect.bottomRight.x === grid.rect.bottomRight.x;
+  const isLastRow = cell.rect.bottomRight.y === grid.rect.bottomRight.y;
+
+  // ctx.fillStyle = colors.green[4] + "30";
+
+  // ctx.fillRect(
+  //   cell.rect.topLeft.x + 1,
+  //   cell.rect.topLeft.y + 1,
+  //   cell.rect.width - 1,
+  //   cell.rect.height - 1,
+  // );
+
+  ctx.strokeStyle = colors.green[600];
+  ctx.lineWidth = 2;
+
+  ctx.strokeRect(
+    cell.rect.topLeft.x + 1,
+    cell.rect.topLeft.y + 1,
+    isLastCell ? cell.rect.width - 2 : cell.rect.width - 1,
+    isLastRow ? cell.rect.height - 2 : cell.rect.height - 1,
+  );
+}
+
+export default function drawGrid(
+  ctx: CanvasRenderingContext2D,
+  grid: RenderedGrid,
+  selection?: Selection,
+  pendingSelection?: PendingSelection,
+) {
+  const excursion = (f: () => void) => {
+    ctx.save();
+    f();
+    ctx.restore();
+  };
+
+  excursion(() => fillBackground(ctx, grid));
+  excursion(() => strokeGridLines(ctx, grid));
+  excursion(() => strokeGrid(ctx, grid));
+
+  if (pendingSelection) {
+    excursion(() => drawPendingSelection(ctx, grid, pendingSelection));
+  } else if (selection) {
+    excursion(() => drawSelection(ctx, grid, selection));
+  }
+}
diff --git a/web/src/components/grid/index.css b/web/src/components/grid/index.css
index 0fad720..a733015 100644
--- a/web/src/components/grid/index.css
+++ b/web/src/components/grid/index.css
@@ -1,6 +1,5 @@
 ntv-grid {
   display: block;
-  padding: 1.5rem;
 }
 
 ntv-grid > canvas {
diff --git a/web/src/components/grid/index.ts b/web/src/components/grid/index.ts
index 829a511..0acace4 100644
--- a/web/src/components/grid/index.ts
+++ b/web/src/components/grid/index.ts
@@ -1,5 +1,5 @@
 import h, { type CreateElement } from "../../html";
-import renderGrid from "./renderGrid";
+import cellAtCoord from "./cellAtCoord";
 import drawGrid from "./drawGrid";
 import "./index.css";
 
@@ -15,6 +15,10 @@ class NotiveGridElement extends HTMLElement {
     this.setAttribute("grid-id", val);
   }
 
+  get renderedGrid() {
+    return window.notive.getGrid(this.#gridId)!;
+  }
+
   canvasEl: HTMLCanvasElement = h.canvas();
 
   connectedCallback() {
@@ -22,19 +26,41 @@ class NotiveGridElement extends HTMLElement {
       throw new Error("ntv-grid requries gridId attribute");
     }
 
+    this.canvasEl.addEventListener("mousedown", (event) => {
+      const clientRect = this.canvasEl.getBoundingClientRect();
+      const x = event.x - clientRect.x;
+      const y = event.y - clientRect.y;
+      const cellRef = cellAtCoord(this.renderedGrid, x, y);
+      if (!cellRef) return;
+      window.notive.selectCell(this.#gridId, cellRef);
+    });
+
+    window.addEventListener("ntv:selection-changed", () => {
+      this.draw();
+    });
+
     this.append(this.canvasEl);
     this.draw();
   }
 
   draw() {
     const ctx = this.canvasEl.getContext("2d");
+
     if (!ctx) throw new Error("Unable to get canvas context");
+
     const grid = window.notive.getGrid(this.gridId);
+
     if (!grid) return;
-    const renderedGrid = renderGrid(grid);
-    this.canvasEl.setAttribute("width", renderedGrid.rect.width + "px");
-    this.canvasEl.setAttribute("height", renderedGrid.rect.height + "px");
-    drawGrid(ctx, renderedGrid);
+
+    this.canvasEl.setAttribute("width", grid.rect.width + "px");
+    this.canvasEl.setAttribute("height", grid.rect.height + "px");
+
+    drawGrid(
+      ctx,
+      grid,
+      window.notive.selection,
+      window.notive.pendingSelection,
+    );
   }
 }
 
diff --git a/web/src/components/grid/renderGrid.ts b/web/src/components/grid/renderGrid.ts
index 5666f66..7ef8813 100644
--- a/web/src/components/grid/renderGrid.ts
+++ b/web/src/components/grid/renderGrid.ts
@@ -1,6 +1,6 @@
 import Ratio from "../../math/Ratio";
 import Rect from "../../math/Rect";
-import { Cell, CellRef, Grid, Row, RowRef } from "./types";
+import { Cell, CellRef, Grid, Row, RowRef } from "../../types";
 
 export interface RenderedCell extends Cell {
   cellRef: CellRef;