4 files changed, 213 insertions, 56 deletions

diff --git a/web/src/components/app/index.ts b/web/src/components/app/index.ts
index 910aa52..ec40754 100644
--- a/web/src/components/app/index.ts
+++ b/web/src/components/app/index.ts
@@ -1,4 +1,3 @@
-import h from "../../html";
 import ntvGrid from "../grid";
 import ntvToolbar from "../toolbar";
 import "./index.css";
diff --git a/web/src/components/grid/drawGrid.ts b/web/src/components/grid/drawGrid.ts
index 8e64479..5ea17b6 100644
--- a/web/src/components/grid/drawGrid.ts
+++ b/web/src/components/grid/drawGrid.ts
@@ -1,21 +1,61 @@
-import colors from "tailwindcss/colors";
-import { PendingSelection, Selection } from "../../selection";
+import { RangeSelection, Selection } from "../../selection";
 import { CellRef } from "../../types";
 import { RenderedCell, RenderedGrid } from "./renderGrid";
 
-function fillBackground(ctx: CanvasRenderingContext2D, grid: RenderedGrid) {
+interface GridColors {
+  bgFill: string;
+  borderStroke: string;
+  cellStroke: string;
+  selelectionRangeFill: string;
+  selectionRangeStroke: string;
+  activeCellStroke: string;
+}
+
+export function getGridColors(el: HTMLElement): GridColors {
+  const style = window.getComputedStyle(el);
+  const color = (k: string) => style.getPropertyValue(k);
+
+  return {
+    bgFill: color("--grid-bg-fill"),
+    borderStroke: color("--grid-border-stroke"),
+    cellStroke: color("--grid-cell-stroke"),
+    selelectionRangeFill: color("--grid-selection-range-fill"),
+    selectionRangeStroke: color("--grid-selection-range-stroke"),
+    activeCellStroke: color("--grid-active-cell-stroke"),
+  };
+}
+
+function excursion(ctx: CanvasRenderingContext2D, f: () => void) {
+  ctx.save();
+  f();
+  ctx.restore();
+}
+
+function fillBackground(
+  ctx: CanvasRenderingContext2D,
+  colors: GridColors,
+  grid: RenderedGrid,
+) {
   ctx.clearRect(0, 0, grid.rect.width, grid.rect.height);
-  ctx.fillStyle = colors.neutral[900];
+  ctx.fillStyle = colors.bgFill;
   ctx.fillRect(0, 0, grid.rect.width, grid.rect.height);
 }
 
-function strokeGrid(ctx: CanvasRenderingContext2D, grid: RenderedGrid) {
-  ctx.strokeStyle = colors.neutral[700];
+function strokeGrid(
+  ctx: CanvasRenderingContext2D,
+  colors: GridColors,
+  grid: RenderedGrid,
+) {
+  ctx.strokeStyle = colors.borderStroke;
   ctx.strokeRect(0.5, 0.5, grid.rect.width - 1, grid.rect.height - 1);
 }
 
-function strokeGridLines(ctx: CanvasRenderingContext2D, grid: RenderedGrid) {
-  ctx.strokeStyle = colors.neutral[800];
+function strokeGridLines(
+  ctx: CanvasRenderingContext2D,
+  colors: GridColors,
+  grid: RenderedGrid,
+) {
+  ctx.strokeStyle = colors.cellStroke;
 
   grid.renderedRows.forEach((row, renderedRowIndex) => {
     const isLastRow = renderedRowIndex === grid.renderedRows.length - 1;
@@ -43,65 +83,127 @@ function getRenderedCell(
   return grid.renderedRows[renderedRowIndex]?.renderedCells[cellRef.cellIndex];
 }
 
-function drawPendingSelection(
+function strokeActiveCell(
   ctx: CanvasRenderingContext2D,
+  colors: GridColors,
   grid: RenderedGrid,
-  selection: PendingSelection,
-) {}
+  cell: RenderedCell,
+) {
+  const isLastCell = cell.rect.bottomRight.x === grid.rect.bottomRight.x;
+  const isLastRow = cell.rect.bottomRight.y === grid.rect.bottomRight.y;
 
-function drawSelection(
+  ctx.strokeStyle = colors.activeCellStroke;
+  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,
+  );
+}
+
+function drawCellRange(
   ctx: CanvasRenderingContext2D,
+  colors: GridColors,
   grid: RenderedGrid,
-  selection: Selection,
+  start: CellRef,
+  end: CellRef,
+  { stroke }: { stroke: boolean },
 ) {
-  if (selection.gridId !== grid.id) return;
+  const startCell = getRenderedCell(grid, start);
+  const endCell = getRenderedCell(grid, end);
 
-  const cell = getRenderedCell(grid, selection.activeCellRef);
+  if (!startCell || !endCell) return;
 
-  if (!cell) return;
+  const rect = startCell.rect.extend(endCell.rect);
 
-  const isLastCell = cell.rect.bottomRight.x === grid.rect.bottomRight.x;
-  const isLastRow = cell.rect.bottomRight.y === grid.rect.bottomRight.y;
+  const isRightEdge = rect.bottomRight.x === grid.rect.bottomRight.x;
+  const isBottomEdge = rect.bottomRight.y === grid.rect.bottomRight.y;
+
+  ctx.fillStyle = colors.selelectionRangeFill;
 
-  // ctx.fillStyle = colors.green[4] + "30";
+  ctx.fillRect(
+    rect.topLeft.x + 1,
+    rect.topLeft.y + 1,
+    isRightEdge ? rect.width - 2 : rect.width - 1,
+    isBottomEdge ? rect.height - 2 : rect.height - 1,
+  );
 
-  // ctx.fillRect(
-  //   cell.rect.topLeft.x + 1,
-  //   cell.rect.topLeft.y + 1,
-  //   cell.rect.width - 1,
-  //   cell.rect.height - 1,
-  // );
+  if (!stroke) return;
 
-  ctx.strokeStyle = colors.green[400];
-  ctx.lineWidth = 2;
+  ctx.strokeStyle = colors.selectionRangeStroke;
 
   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,
+    rect.topLeft.x + 0.5,
+    rect.topLeft.y + 0.5,
+    isRightEdge ? rect.width - 1 : rect.width,
+    isBottomEdge ? rect.height - 1 : rect.height,
   );
 }
 
+function drawPendingSelection(
+  ctx: CanvasRenderingContext2D,
+  colors: GridColors,
+  grid: RenderedGrid,
+  selection: Selection,
+) {
+  if (selection.gridId !== grid.id) return;
+
+  const activeCell = getRenderedCell(grid, selection.activeCellRef);
+
+  if (!activeCell) return;
+
+  if (selection instanceof RangeSelection) {
+    excursion(ctx, () => {
+      drawCellRange(ctx, colors, grid, selection.range[0], selection.range[1], {
+        stroke: false,
+      });
+    });
+  }
+
+  excursion(ctx, () => strokeActiveCell(ctx, colors, grid, activeCell));
+}
+
+function drawSelection(
+  ctx: CanvasRenderingContext2D,
+  colors: GridColors,
+  grid: RenderedGrid,
+  selection: Selection,
+) {
+  if (selection.gridId !== grid.id) return;
+
+  const activeCell = getRenderedCell(grid, selection.activeCellRef);
+
+  if (!activeCell) return;
+
+  if (selection instanceof RangeSelection) {
+    excursion(ctx, () => {
+      drawCellRange(ctx, colors, grid, selection.range[0], selection.range[1], {
+        stroke: true,
+      });
+    });
+  }
+
+  excursion(ctx, () => strokeActiveCell(ctx, colors, grid, activeCell));
+}
+
 export default function drawGrid(
   ctx: CanvasRenderingContext2D,
+  colors: GridColors,
   grid: RenderedGrid,
   selection?: Selection,
-  pendingSelection?: PendingSelection,
+  pendingSelection?: Selection,
 ) {
-  const excursion = (f: () => void) => {
-    ctx.save();
-    f();
-    ctx.restore();
-  };
-
-  excursion(() => fillBackground(ctx, grid));
-  excursion(() => strokeGridLines(ctx, grid));
-  excursion(() => strokeGrid(ctx, grid));
+  excursion(ctx, () => fillBackground(ctx, colors, grid));
+  excursion(ctx, () => strokeGridLines(ctx, colors, grid));
+  excursion(ctx, () => strokeGrid(ctx, colors, grid));
 
   if (pendingSelection) {
-    excursion(() => drawPendingSelection(ctx, grid, pendingSelection));
+    excursion(ctx, () =>
+      drawPendingSelection(ctx, colors, grid, pendingSelection),
+    );
   } else if (selection) {
-    excursion(() => drawSelection(ctx, grid, selection));
+    excursion(ctx, () => drawSelection(ctx, colors, grid, selection));
   }
 }
diff --git a/web/src/components/grid/index.css b/web/src/components/grid/index.css
index a733015..825a74a 100644
--- a/web/src/components/grid/index.css
+++ b/web/src/components/grid/index.css
@@ -1,5 +1,16 @@
 ntv-grid {
   display: block;
+
+  --grid-bg-fill: var(--color-neutral-900);
+  --grid-border-stroke: var(--color-neutral-700);
+  --grid-cell-stroke: var(--color-neutral-800);
+  --grid-active-cell-stroke: var(--color-green-400);
+  --grid-selection-range-fill: color-mix(
+    in oklab,
+    var(--color-green-400) 10%,
+    transparent
+  );
+  --grid-selection-range-stroke: var(--color-green-400);
 }
 
 ntv-grid > canvas {
diff --git a/web/src/components/grid/index.ts b/web/src/components/grid/index.ts
index 0acace4..fbb9c60 100644
--- a/web/src/components/grid/index.ts
+++ b/web/src/components/grid/index.ts
@@ -1,6 +1,7 @@
 import h, { type CreateElement } from "../../html";
+import { CellRef } from "../../types";
 import cellAtCoord from "./cellAtCoord";
-import drawGrid from "./drawGrid";
+import drawGrid, { getGridColors } from "./drawGrid";
 import "./index.css";
 
 class NotiveGridElement extends HTMLElement {
@@ -26,18 +27,12 @@ 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());
 
-    window.addEventListener("ntv:selection-changed", () => {
-      this.draw();
-    });
+    this.canvasEl.addEventListener(
+      "mousedown",
+      this.#canvasMouseDownCallback.bind(this),
+    );
 
     this.append(this.canvasEl);
     this.draw();
@@ -55,13 +50,63 @@ class NotiveGridElement extends HTMLElement {
     this.canvasEl.setAttribute("width", grid.rect.width + "px");
     this.canvasEl.setAttribute("height", grid.rect.height + "px");
 
+    const colors = getGridColors(this);
+
     drawGrid(
       ctx,
+      colors,
       grid,
       window.notive.selection,
       window.notive.pendingSelection,
     );
   }
+
+  #mouseEventCellRef(
+    this: NotiveGridElement,
+    event: MouseEvent,
+  ): CellRef | undefined {
+    const clientRect = this.canvasEl.getBoundingClientRect();
+    const x = event.x - clientRect.x;
+    const y = event.y - clientRect.y;
+    return cellAtCoord(this.renderedGrid, x, y);
+  }
+
+  #canvasMouseDownCallback(this: NotiveGridElement, event: MouseEvent) {
+    const cellRef = this.#mouseEventCellRef(event);
+
+    if (!cellRef) return;
+
+    window.notive.startSelecting(this.gridId, cellRef);
+
+    this.#selectionAbortController = new AbortController();
+    const { signal } = this.#selectionAbortController;
+
+    window.addEventListener(
+      "mousemove",
+      this.#selectionMouseMoveCallback.bind(this),
+      { signal },
+    );
+
+    window.addEventListener(
+      "mouseup",
+      this.#selectionMouseUpCallback.bind(this),
+      { signal },
+    );
+  }
+
+  #selectionAbortController?: AbortController;
+
+  #selectionMouseMoveCallback(this: NotiveGridElement, event: MouseEvent) {
+    const cellRef = this.#mouseEventCellRef(event);
+    if (!cellRef) return;
+    window.notive.extendSelection(cellRef);
+  }
+
+  #selectionMouseUpCallback(this: NotiveGridElement, event: MouseEvent) {
+    this.#selectionAbortController?.abort();
+    this.#selectionAbortController = undefined;
+    window.notive.finishSelecting();
+  }
 }
 
 customElements.define("ntv-grid", NotiveGridElement);