[Init] Initial commit - NetMesh terminal manager

application/state/terminalDragData.ts

@@ -0,0 +1,62 @@
+export const WORKSPACE_SESSION_DRAG_TYPE = 'application/x-netcatty-workspace-session';
+
+type DataTransferLike = {
+  types: DOMStringList | readonly string[];
+  getData: (format: string) => string;
+};
+
+export function dataTransferHasType(dataTransfer: Pick<DataTransferLike, 'types'>, type: string): boolean {
+  return Array.prototype.includes.call(dataTransfer.types, type);
+}
+
+export function hasWorkspaceSessionDrag(dataTransfer: Pick<DataTransferLike, 'types'>): boolean {
+  return dataTransferHasType(dataTransfer, WORKSPACE_SESSION_DRAG_TYPE);
+}
+
+export function getWorkspaceSessionDragId(dataTransfer: DataTransferLike): string {
+  return dataTransfer.getData(WORKSPACE_SESSION_DRAG_TYPE) || dataTransfer.getData('session-id');
+}
+
+export function isPointInsideRect(
+  point: { clientX: number; clientY: number },
+  rect: Pick<DOMRect, 'left' | 'right' | 'top' | 'bottom'>,
+): boolean {
+  return point.clientX >= rect.left
+    && point.clientX <= rect.right
+    && point.clientY >= rect.top
+    && point.clientY <= rect.bottom;
+}
+
+export type TopTabInsertionTarget = {
+  tabId: string;
+  position: 'before' | 'after';
+};
+
+export function getTopTabInsertionTarget(
+  point: { clientX: number; clientY: number },
+  topTabsRoot: HTMLElement | null,
+): TopTabInsertionTarget | null {
+  if (!topTabsRoot || !isPointInsideRect(point, topTabsRoot.getBoundingClientRect())) return null;
+
+  const tabs = Array.from(topTabsRoot.querySelectorAll<HTMLElement>('[data-tab-id]'))
+    .filter((tab) => tab.dataset.tabType !== 'root');
+
+  if (tabs.length === 0) return null;
+
+  for (const tab of tabs) {
+    const rect = tab.getBoundingClientRect();
+    const midpoint = rect.left + rect.width / 2;
+    const tabId = tab.dataset.tabId;
+    if (!tabId) continue;
+    if (point.clientX <= midpoint) {
+      return { tabId, position: 'before' };
+    }
+    if (point.clientX <= rect.right) {
+      return { tabId, position: 'after' };
+    }
+  }
+
+  const lastTab = tabs[tabs.length - 1];
+  const lastTabId = lastTab?.dataset.tabId;
+  return lastTabId ? { tabId: lastTabId, position: 'after' } : null;
+}