feat(input): drag artboard transform controls

input/index.ts

@@ -6,6 +6,8 @@ export {
 export type { CommandKeybind, GlobalKeybindConsumer, Keybind, KeybindEvent, KeybindMap } from "./keyboard";
 export { handleKeybind, keybindFromEvent } from "./keyboard";
 export { handleArtboardSelection } from "./selection";
+export { createTransformControlsInputController, hitTestArtboardTransformHandle } from "./transform-controls";
+export type { TransformControlsInputController } from "./transform-controls";
 export type { ViewportPanInputController } from "./viewport-pan";
 export { createViewportPanInputController } from "./viewport-pan";
 export type { GlobalPointerConsumer, GlobalWheelConsumer, PointerInputEvent, WheelInputEvent } from "./pointer";

input/transform-controls.test.ts

@@ -0,0 +1,66 @@
+import { describe, expect, test } from "bun:test";
+import { commandIds } from "@commands/ids";
+import { createInitialAppState } from "@editor/initial-state";
+import type { PointerInputEvent } from "./pointer";
+import { createTransformControlsInputController, hitTestArtboardTransformHandle } from "./transform-controls";
+
+const ignoredState = undefined as never;
+
+describe("transform controls input", () => {
+  test("hit tests artboard handles and body", () => {
+    const viewport = { center: { x: 0, y: 0 }, zoom: 1, rotation: 0, size: { w: 200, h: 200 } };
+    const bounds = { x: -50, y: -50, w: 100, h: 100 };
+
+    expect(hitTestArtboardTransformHandle({ x: 50, y: 50 }, bounds, viewport)).toBe("nw");
+    expect(hitTestArtboardTransformHandle({ x: 100, y: 100 }, bounds, viewport)).toBe("body");
+    expect(hitTestArtboardTransformHandle({ x: 10, y: 10 }, bounds, viewport)).toBeUndefined();
+  });
+
+  test("dispatches transform lifecycle for selected artboard", () => {
+    let state = {
+      ...createInitialAppState("Test"),
+      document: {
+        ...createInitialAppState("Test").document,
+        artboards: [{ id: "a1", name: "Artboard", bounds: { x: -50, y: -50, w: 100, h: 100 }, backgroundColor: "transparent", layers: [] }],
+      },
+      editor: {
+        ...createInitialAppState("Test").editor,
+        viewport: { center: { x: 0, y: 0 }, zoom: 1, rotation: 0, size: { w: 200, h: 200 } },
+        selection: { artboardId: "a1", layerIds: [] },
+      },
+    };
+    const dispatched: unknown[] = [];
+    const controller = createTransformControlsInputController({
+      getDocument: () => state.document,
+      getEditor: () => state.editor,
+      dispatch: (commandId, payload) => {
+        dispatched.push({ commandId, payload });
+        if (commandId === commandIds.transformBegin) state = { ...state, editor: { ...state.editor, transformSession: payload as never } };
+        return ignoredState;
+      },
+    });
+
+    expect(controller.pointerDown(pointerEvent({ position: { x: 100, y: 100 }, buttons: 1 }))).toBe(true);
+    expect(controller.pointerMove(pointerEvent({ position: { x: 110, y: 120 }, buttons: 1 }))).toBe(true);
+    expect(controller.pointerUp(pointerEvent({ position: { x: 110, y: 120 }, buttons: 0 }))).toBe(true);
+    expect(dispatched.map((event) => (event as { commandId: string }).commandId)).toEqual([
+      commandIds.transformBegin,
+      commandIds.transformUpdate,
+      commandIds.transformEnd,
+    ]);
+  });
+});
+
+function pointerEvent(overrides: Partial<PointerInputEvent>): PointerInputEvent {
+  return {
+    pointerId: 1,
+    pointerType: "mouse",
+    position: { x: 0, y: 0 },
+    buttons: 0,
+    altKey: false,
+    ctrlKey: false,
+    metaKey: false,
+    shiftKey: false,
+    ...overrides,
+  };
+}

input/transform-controls.ts

@@ -0,0 +1,102 @@
+import { commandIds } from "@commands/ids";
+import type { Dispatch } from "@commands/dispatcher";
+import type { ImageDocument } from "@core/document";
+import type { Rect, Vec2D } from "@core/geometry";
+import type { EditorState } from "@editor/state";
+import type { TransformHandle } from "@editor/transform";
+import type { PointerInputEvent } from "./pointer";
+
+export type TransformControlsInputController = {
+  pointerDown(event: PointerInputEvent): boolean;
+  pointerMove(event: PointerInputEvent): boolean;
+  pointerUp(event: PointerInputEvent): boolean;
+};
+
+export function createTransformControlsInputController(options: {
+  getDocument: () => ImageDocument;
+  getEditor: () => EditorState;
+  dispatch: Dispatch;
+}): TransformControlsInputController {
+  return {
+    pointerDown(event) {
+      if (event.pointerType !== "mouse" || (event.buttons & 1) !== 1) return false;
+
+      const editor = options.getEditor();
+      const artboardId = editor.selection.artboardId;
+      if (!artboardId || editor.tools.activeTool !== "select") return false;
+
+      const artboard = options.getDocument().artboards.find((candidate) => candidate.id === artboardId);
+      if (!artboard) return false;
+
+      const handle = hitTestArtboardTransformHandle(event.position, artboard.bounds, editor.viewport);
+      if (!handle) return false;
+
+      options.dispatch(commandIds.transformBegin, {
+        target: { type: "artboard", id: artboard.id },
+        handle,
+        point: viewportPointToDocumentPoint(event.position, editor.viewport),
+        initialBounds: artboard.bounds,
+      });
+      return true;
+    },
+    pointerMove(event) {
+      const editor = options.getEditor();
+      if (!editor.transformSession) return false;
+
+      options.dispatch(commandIds.transformUpdate, { point: viewportPointToDocumentPoint(event.position, editor.viewport) });
+      return true;
+    },
+    pointerUp() {
+      if (!options.getEditor().transformSession) return false;
+
+      options.dispatch(commandIds.transformEnd, undefined);
+      return true;
+    },
+  };
+}
+
+export function hitTestArtboardTransformHandle(position: Vec2D, bounds: Rect, viewport: EditorState["viewport"]): TransformHandle | undefined {
+  const rect = documentRectToViewportRect(bounds, viewport);
+  const handles = transformHandleRects(rect);
+  const handle = handles.find((candidate) => pointInRect(position, candidate.rect));
+  if (handle) return handle.handle;
+  if (pointInRect(position, rect)) return "body";
+  return undefined;
+}
+
+function transformHandleRects(rect: Rect): { handle: TransformHandle; rect: Rect }[] {
+  const size = 12;
+  const half = size / 2;
+  const points: { handle: TransformHandle; point: Vec2D }[] = [
+    { handle: "nw", point: { x: rect.x, y: rect.y } },
+    { handle: "n", point: { x: rect.x + rect.w / 2, y: rect.y } },
+    { handle: "ne", point: { x: rect.x + rect.w, y: rect.y } },
+    { handle: "e", point: { x: rect.x + rect.w, y: rect.y + rect.h / 2 } },
+    { handle: "se", point: { x: rect.x + rect.w, y: rect.y + rect.h } },
+    { handle: "s", point: { x: rect.x + rect.w / 2, y: rect.y + rect.h } },
+    { handle: "sw", point: { x: rect.x, y: rect.y + rect.h } },
+    { handle: "w", point: { x: rect.x, y: rect.y + rect.h / 2 } },
+  ];
+
+  return points.map(({ handle, point }) => ({ handle, rect: { x: point.x - half, y: point.y - half, w: size, h: size } }));
+}
+
+function viewportPointToDocumentPoint(point: Vec2D, viewport: EditorState["viewport"]): Vec2D {
+  return {
+    x: viewport.center.x + (point.x - viewport.size.w / 2) / viewport.zoom,
+    y: viewport.center.y + (point.y - viewport.size.h / 2) / viewport.zoom,
+  };
+}
+
+function documentRectToViewportRect(rect: Rect, viewport: EditorState["viewport"]): Rect {
+  return {
+    x: viewport.size.w / 2 + (rect.x - viewport.center.x) * viewport.zoom,
+    y: viewport.size.h / 2 + (rect.y - viewport.center.y) * viewport.zoom,
+    w: rect.w * viewport.zoom,
+    h: rect.h * viewport.zoom,
+  };
+}
+
+function pointInRect(point: Vec2D, rect: Rect) {
+  return point.x >= rect.x && point.x <= rect.x + rect.w && point.y >= rect.y && point.y <= rect.y + rect.h;
+}