[Init] Initial commit - NetMesh terminal manager

components/terminalLayer/workspaceSplitResize.ts

@@ -0,0 +1,92 @@
+import type { Workspace, WorkspaceNode } from '../../types';
+
+export type WorkspaceResizeSession = {
+  workspaceId: string;
+  splitId: string;
+  index: number;
+  direction: 'vertical' | 'horizontal';
+  startSizes: number[];
+  startArea: { x: number; y: number; w: number; h: number };
+  startClient: { x: number; y: number };
+};
+
+function clampAdjacentPaneSizes(
+  pxSizes: number[],
+  index: number,
+  delta: number,
+  dimension: number,
+): number[] {
+  const i = index;
+  let a = pxSizes[i] + delta;
+  let b = pxSizes[i + 1] - delta;
+  const minPx = Math.min(120, dimension / 2);
+  if (a < minPx) {
+    const diff = minPx - a;
+    a = minPx;
+    b -= diff;
+  }
+  if (b < minPx) {
+    const diff = minPx - b;
+    b = minPx;
+    a -= diff;
+  }
+  const next = [...pxSizes];
+  next[i] = Math.max(minPx, a);
+  next[i + 1] = Math.max(minPx, b);
+  return next;
+}
+
+export function computeSplitPxSizesFromDelta(
+  session: WorkspaceResizeSession,
+  delta: number,
+): number[] | null {
+  const dimension = session.direction === 'vertical' ? session.startArea.w : session.startArea.h;
+  if (dimension <= 0) return null;
+  const total = session.startSizes.reduce((acc, n) => acc + n, 0) || 1;
+  const pxSizes = session.startSizes.map((s) => (s / total) * dimension);
+  return clampAdjacentPaneSizes(pxSizes, session.index, delta, dimension);
+}
+
+export function computeSplitSizesFromDelta(
+  session: WorkspaceResizeSession,
+  delta: number,
+): number[] {
+  const pxSizes = computeSplitPxSizesFromDelta(session, delta);
+  if (!pxSizes) return [...session.startSizes];
+  const totalPx = pxSizes.reduce((acc, n) => acc + n, 0) || 1;
+  return pxSizes.map((n) => n / totalPx);
+}
+
+/** Workspace-local pixel coordinate of the split boundary after applying delta. */
+export function computeResizeBoundary(
+  session: WorkspaceResizeSession,
+  delta: number,
+): number | null {
+  const pxSizes = computeSplitPxSizesFromDelta(session, delta);
+  if (!pxSizes) return null;
+  let offset = 0;
+  for (let i = 0; i <= session.index; i += 1) {
+    offset += pxSizes[i];
+  }
+  return session.direction === 'vertical'
+    ? session.startArea.x + offset
+    : session.startArea.y + offset;
+}
+
+export function patchWorkspaceSplitSizes(
+  workspace: Workspace,
+  splitId: string,
+  sizes: number[],
+): Workspace {
+  const patch = (node: WorkspaceNode): WorkspaceNode => {
+    if (node.type === 'pane') return node;
+    const children = node.children.map(patch);
+    if (node.id === splitId) {
+      return { ...node, children, sizes: [...sizes] };
+    }
+    const childrenChanged = children.some((child, idx) => child !== node.children[idx]);
+    return childrenChanged ? { ...node, children } : node;
+  };
+  const root = patch(workspace.root);
+  return root === workspace.root ? workspace : { ...workspace, root };
+}