pan and select

editor/src/App.tsx

@@ -1,5 +1,5 @@
 import { useState, type ReactElement } from "react";
-import "./App.css";
+import "./style.css";
 import Canvas from "./Canvas";
 import { Editor } from "./Editor";
 import Toolbar from "./Toolbar";
@@ -10,8 +10,10 @@ function App(): ReactElement {
   return (
     <>
       <h1>nandsim</h1>
-      <Canvas editor={editor} />
+      <div className="Editor">
         <Toolbar editor={editor} />
+        <Canvas editor={editor} />
+      </div>
     </>
   );
 }

editor/src/Canvas.css

@@ -1,6 +0,0 @@
-
-.EditorView {
-    canvas {
-        image-rendering: pixelated;
-    }
-}

editor/src/Canvas.tsx

@@ -1,5 +1,4 @@
 import { useEffect, useRef, type ReactElement } from "react";
-import "./Canvas.css";
 import { V2, type Editor } from "./Editor";
 
 type Props = { editor: Editor };
@@ -15,7 +14,7 @@ function Canvas({ editor }: Props): ReactElement {
 
   return (
     <>
-      <div className="EditorView">
+      <div className="Canvas">
         <canvas
           ref={ref}
           width={1000}
@@ -37,10 +36,10 @@ function Canvas({ editor }: Props): ReactElement {
             editor.renderIfNeeded(ev.target as HTMLCanvasElement);
           }}
           onKeyDown={(ev) => {
-            console.log(ev.key);
+            editor.keyDown(ev.key);
           }}
           onKeyUp={(ev) => {
-            console.log(ev.key);
+            editor.keyUp(ev.key);
           }}
         />
       </div>

editor/src/Editor.ts

@@ -2,24 +2,78 @@ export type V2 = { x: number; y: number };
 export const V2 = (x: number, y: number): V2 => ({ x, y });
 
 export class Editor {
-  private offset = V2(0, 0);
+  private cx = new Cx();
-  private dragging = false;
-  private renderNeeded = false;
 
   render(canvas: HTMLCanvasElement) {
-    const cx = canvas.getContext("2d")!;
+    this.cx.render(canvas);
+  }
 
-    cx.imageSmoothingEnabled = false;
+  renderIfNeeded(canvas: HTMLCanvasElement) {
-    cx.fillStyle = "#666";
+    this.cx.renderIfNeeded(canvas);
-    cx.fillRect(0, 0, canvas.width, canvas.height);
+  }
+
+  mouseDown(pos: V2) {
+    this.cx.mouseDown(pos);
+  }
+
+  mouseUp(pos: V2) {
+    this.cx.mouseUp(pos);
+  }
+
+  mouseMove(deltaPos: V2) {
+    this.cx.mouseMove(deltaPos);
+  }
+
+  keyDown(key: string) {
+    this.cx.keyDown(key);
+  }
+
+  keyUp(key: string) {
+    this.cx.keyUp(key);
+  }
+
+  selectTool(tool: Tool) {
+    this.cx.selectTool(tool);
+  }
+
+  selectedTool(): Tool | null {
+    return this.cx.selectedTool();
+  }
+
+  tools(): Tool[] {
+    return ["select", "pan", "and"];
+  }
+
+  addUpdateAction(action: () => void): object {
+    return this.cx.addUpdateAction(action);
+  }
+
+  removeUpdateAction(actionId: object) {
+    this.cx.removeUpdateAction(actionId);
+  }
+}
+
+class Cx {
+  private offset = V2(0, 0);
+  private renderNeeded = false;
+  private state = new Normal(this) as State;
+  private updateActions: (() => void)[] = [];
+  private selectionRect: SelectionRect | null = null;
+
+  render(canvas: HTMLCanvasElement) {
+    const c = canvas.getContext("2d")!;
+
+    c.imageSmoothingEnabled = false;
+    c.fillStyle = "#666";
+    c.fillRect(0, 0, canvas.width, canvas.height);
 
     const gridSize = { x: 20, y: 20 };
     const dotSize = { x: 2, y: 2 };
 
-    cx.fillStyle = "#111";
+    c.fillStyle = "#111";
     for (let y = 0; y < canvas.width / gridSize.x + 1; ++y) {
       for (let x = 0; x < canvas.height / gridSize.y + 1; ++x) {
-        cx.fillRect(
+        c.fillRect(
           (this.offset.x % gridSize.x) + x * gridSize.x - dotSize.x / 2,
           (this.offset.y % gridSize.y) + y * gridSize.y - dotSize.y / 2,
           dotSize.x,
@@ -27,6 +81,19 @@ export class Editor {
         );
       }
     }
+
+    if (this.selectionRect) {
+      const {
+        pos: { x, y },
+        size: { x: w, y: h },
+      } = this.selectionRect;
+
+      c.fillStyle = `#ff880088`;
+      c.fillRect(x, y, w, h);
+      c.strokeStyle = `#ff8800`;
+      c.lineWidth = 2;
+      c.strokeRect(x, y, w, h);
+    }
   }
 
   renderIfNeeded(canvas: HTMLCanvasElement) {
@@ -37,22 +104,175 @@ export class Editor {
   }
 
   mouseDown(pos: V2) {
-    this.dragging = true;
+    this.state.onMouseDown?.(pos);
   }
-
   mouseUp(pos: V2) {
-    this.dragging = false;
+    this.state.onMouseUp?.(pos);
+  }
+  mouseMove(deltaPos: V2) {
+    this.state.onMouseMove?.(deltaPos);
+  }
+  keyDown(key: string) {
+    this.state.onKeyDown?.(key);
+  }
+  keyUp(key: string) {
+    this.state.onKeyUp?.(key);
+  }
+  selectTool(tool: Tool) {
+    this.state.selectTool?.(tool);
+  }
+  selectedTool(): Tool | null {
+    return this.state.selectedTool?.() ?? null;
   }
 
-  mouseMove(deltaPos: V2) {
+  addUpdateAction(action: () => void): object {
-    if (this.dragging) {
+    this.updateActions.push(action);
+    return action;
+  }
+
+  removeUpdateAction(actionId: object) {
+    this.updateActions = this.updateActions.filter(
+      (action) => action !== actionId,
+    );
+  }
+
+  transitionTo<S extends { new (cx: Cx): State }>(S: S) {
+    this.state = new S(this);
+    this.notifyListeners();
+  }
+
+  notifyListeners() {
+    for (const action of this.updateActions) {
+      action();
+    }
+  }
+
+  moveOffset(deltaPos: V2) {
     this.offset.x += deltaPos.x;
     this.offset.y += deltaPos.y;
     this.renderNeeded = true;
   }
+
+  addSelectionRect(pos: V2) {
+    this.selectionRect = { pos, size: V2(0, 0) };
+    this.renderNeeded = true;
   }
 
-  selectTool(tool: Tool) {}
+  removeSelectionRect() {
+    this.selectionRect = null;
+    this.renderNeeded = true;
   }
 
-type Tool = "and" | "not" | "pin in" | "pin out";
+  moveSelectionRect(deltaPos: V2) {
+    if (this.selectionRect) {
+      this.selectionRect.size.x += deltaPos.x;
+      this.selectionRect.size.y += deltaPos.y;
+      this.renderNeeded = true;
+    }
+  }
+}
+
+interface State {
+  onMouseDown?(pos: V2): void;
+  onMouseUp?(pos: V2): void;
+  onMouseMove?(deltaPos: V2): void;
+  onKeyDown?(key: string): void;
+  onKeyUp?(key: string): void;
+  selectTool?(tool: Tool): void;
+  selectedTool?(): Tool | null;
+}
+
+class Normal implements State {
+  constructor(private cx: Cx) {}
+
+  selectTool(tool: Tool): void {
+    switch (tool) {
+      case "pan":
+        this.cx.transitionTo(Panning);
+        break;
+    }
+  }
+
+  onMouseDown(pos: V2): void {
+    this.cx.addSelectionRect(pos);
+    this.cx.transitionTo(Selecting);
+  }
+
+  onKeyDown(key: string): void {
+    if (key === "Shift") {
+      this.cx.transitionTo(Panning);
+      return;
+    }
+  }
+
+  selectedTool(): Tool | null {
+    return "select";
+  }
+}
+
+class Panning implements State {
+  private dragging = false;
+
+  constructor(private cx: Cx) {}
+
+  onMouseDown(_pos: V2): void {
+    this.dragging = true;
+  }
+
+  onMouseUp(_pos: V2): void {
+    this.dragging = false;
+  }
+
+  onMouseMove(deltaPos: V2): void {
+    if (this.dragging) {
+      this.cx.moveOffset(deltaPos);
+    }
+  }
+
+  onKeyDown(key: string): void {
+    if (key === "Escape") {
+      this.cx.transitionTo(Normal);
+      return;
+    }
+  }
+
+  onKeyUp(key: string): void {
+    if (key === "Shift") {
+      this.cx.transitionTo(Normal);
+      return;
+    }
+  }
+
+  selectTool(tool: Tool): void {
+    this.cx.transitionTo(Normal);
+    this.cx.selectTool(tool);
+  }
+
+  selectedTool(): Tool | null {
+    return "pan";
+  }
+}
+
+type SelectionRect = {
+  pos: V2;
+  size: V2;
+};
+
+class Selecting implements State {
+  constructor(private cx: Cx) {}
+
+  onMouseUp(_pos: V2): void {
+    this.cx.removeSelectionRect();
+    this.cx.transitionTo(Normal);
+  }
+
+  onMouseMove(deltaPos: V2): void {
+    this.cx.moveSelectionRect(deltaPos);
+  }
+
+  selectedTool(): Tool | null {
+    return "select";
+  }
+}
+
+type Tool = "select" | "pan" | "and";

editor/src/Toolbar.tsx

@@ -1,16 +1,33 @@
-import type { ReactElement } from "react";
+import { useEffect, useState, type ReactElement } from "react";
 import type { Editor } from "./Editor";
 
 type Props = { editor: Editor };
 
+function useUpdate(): [number, () => void] {
+  const [value, setValue] = useState(0);
+  return [value, () => setValue(value + 1)] as const;
+}
+
 function Toolbar({ editor }: Props): ReactElement {
+  const [uid, update] = useUpdate();
+
+  useEffect(() => {
+    const handle = editor.addUpdateAction(() => update());
+    return () => editor.removeUpdateAction(handle);
+  });
+
   return (
     <>
-      <div>
+      <div className="Toolbar">
-        <button onClick={() => editor.selectTool("and")}>and</button>
+        {editor.tools().map((tool, key) => (
-        <button onClick={() => editor.selectTool("not")}>not</button>
+          <button
-        <button onClick={() => editor.selectTool("pin in")}>pin in</button>
+            key={`${uid}${key}`}
-        <button onClick={() => editor.selectTool("pin out")}>pin out</button>
+            className={editor.selectedTool() === tool ? "active" : ""}
+            onClick={() => editor.selectTool(tool)}
+          >
+            {tool}
+          </button>
+        ))}
       </div>
     </>
   );

editor/src/index.css

@@ -11,3 +11,7 @@
 body {
   margin: 0;
 }
+
+h1 {
+  margin: 0;
+}

editor/src/style.css

@@ -0,0 +1,37 @@
+
+.Editor {
+    display: flex;
+    flex-direction: row;
+    justify-content: center;
+
+    .Toolbar {
+
+    display: flex;
+    flex-direction: column;
+    gap: 2px;
+
+        button {
+            padding-left: 5px;
+            padding-right: 5px;
+            padding-top: 5px;
+            padding-bottom: 5px;
+
+            font-size: 1rem;
+            text-transform: capitalize;
+
+            width: 200px;
+            text-align: left;
+            border: 2px solid gray;
+            border-radius: 5px;
+        }
+        button.active {
+            border: 2px solid #ff8800;
+        }
+    }
+
+    .Canvas {
+        canvas {
+            image-rendering: pixelated;
+        }
+    }
+}

editor/tsconfig.app.json

@@ -18,7 +18,7 @@
     /* Linting */
     "noUnusedLocals": true,
     "noUnusedParameters": true,
-    "erasableSyntaxOnly": true,
+    // "erasableSyntaxOnly": true, // i don't see why this isn't allowed in app code
     "noFallthroughCasesInSwitch": true
   },
   "include": ["src"]