react-resizable-panels 4.17.0 on Node.js NPM

Add dragging whole tabsets within a Workspace. A tabset is dragged by the empty space in its header, or by a TabsetDragHandle (or any element with a data-tabset-drag-handle attribute) when it has one. Dropping a tabset onto the edge of another tabset moves it there; dropping it onto another tabset's center or tab list moves its tabs into that tabset. Tabsets with the keepWhenEmpty flag can only be moved, not merged. Tabsets can't be dragged when they have the new disableDrag flag or contain a tab that does. - #785
- The new moveTabset imperative method, renderTabsetDragPreview prop, and isDragDisabled value (returned by useParentTabsetState) support tabset dragging. A tabset being dragged has a data-tabset-dragging attribute, and the drag preview has a data-drag-type attribute ("tab" or "tabset").
- disableDrop is called for each tab in a dragged tabset, with the target each tab would be dropped at, so existing restrictions apply to tabset drags too. The new tabset argument is set while a whole tabset is dragged.
Add collapsible tabsets to Workspace. A tabset with the new collapsible flag can be collapsed to just its header (e.g. a bottom panel, or a sidebar that collapses to a vertical strip of tabs), by dragging a separator past its minimum size (like a collapsible Panel) or with the new collapseTabset and expandTabset methods; clicking a tab in a collapsed tabset expands it. Whether a tabset is collapsed is saved in the model (collapsed), and its size is the size it expands to. - #787
- useParentTabset returns collapse, expand, and isCollapsed functions, and useParentTabsetState returns isCollapsed and isCollapsible values (e.g. for a collapse button in a tabset's toolbar). Elements within a collapsed tabset have a data-tabset-collapsed attribute.
- onModelChanged reports the new "collapse" and "expand" reasons.
Add the Workspace tabRemovalSelectionBehavior prop, which chooses the tab that's selected when the selected tab is closed (or dragged to another tabset): the tab after it ("adjacent", the default), or the tabset's most recently selected tab ("recent", like an IDE's editor groups). In "recent" mode, each tabset's recently selected tabs are saved in the model (TabsetNode.recentTabIds). - #786

Warning

The tab argument passed to disableDrop may now be undefined, when a tabset without tabs (one with the keepWhenEmpty flag) is dragged. Functions that read tab (e.g. tab.data) should check for this first.