!7

abstract sclass DynTabs extends DynModule {
  sclass Tab { S name, moduleID; }

  transient NotifyingList<Tab> tabs;
  transient JComponent grid;
  Set<S> tabbableLibIDs = syncTreeSet();
  int gapBelow = 0;
  transient O isTabbableModule; // func(module) -> bool
  
  bool isTabbableModule(O mod) {
    if (isTabbableModule != null) ret isTrue(callF(isTabbableModule, mod));
    ret contains(tabbableLibIDs, dm_moduleLibID(mod));
  }
  
  void start2 {}

  start {
    initialBounds();
    tabs = notifyingList(r change + r updateTabs);
    start2();
    dm_vmBus_onMessage_q('moduleStarted, voidfunc(S moduleID) { addTabForModule(moduleID) });
    dm_vmBus_onMessage_q('deletingModule, voidfunc(O module) { removeTabForModule(dm_moduleID(module)) });
    dm_vmBus_onMessage_q('moduleNameChange, voidfunc(O module, S oldName, S newName) { updateTabForModule(dm_moduleID(module)) });
    dm_q(r { for (S moduleID : dm_listModuleIDs()) addTabForModule(moduleID) });
    dm_vmBus_onMessage_q('newActiveModule, vf<O> selectModule);
  }
  
  void initialBounds {
    if (dm_bounds() == null) dm_setBounds(100, 25, dm_desktopWidth()-200, 70);
  }

  visualize {
    grid = hgridWithSpacing(); updateTabs();
    new L l;
    for (fS libID : tabbableLibIDs)
      addAll(l, libID, rThread { dm_showNewModule(libID) });
    ret centerAndEastWithMargins(grid, jPopDownButton("+", toObjectArray(l)));
  }
  
  void updateTabs q {
    if (grid == null) ret;
    replaceComponentsOfHGrid(grid, map(cloneList(tabs), func(final Tab tab) -> JComponent {
      JLabel lbl = setOpaqueBackground(toColor("E0E0E0"), addInnerMargin(3, 0, jcenteredlabel(tab.name)));
      onLeftClick(lbl, r { showModule(tab.moduleID) });
      componentPopupMenuItems_top(lbl,
        "Close Tab", rThread { dm_deleteModule(tab.moduleID) },
        disableMenuItemTextIf(tab == first(tabs), "Move Left"), rThread { syncMoveElementLeft(tabs, tab) },
        disableMenuItemTextIf(tab == last(tabs), "Move Right"), rThread { syncMoveElementRight(tabs, tab) });
      ret lbl;
    }));
    selectModule(dm_activeModule());
  }

  void addTabForModule(S moduleID) {
    if (isTabbableModule(moduleID) && !containsWhere(tabs, +moduleID)) {
      tabs.add(nu Tab(name := moduleName(moduleID), +moduleID));
      if (dm_isVisible(moduleID)) placeUnderMe(moduleID);
    }
  }
  
  void removeTabForModule(S moduleID) { removeWhere(tabs, +moduleID); }
  
  void updateTabForModule(S moduleID) {
    Tab tab = firstWhere(tabs, +moduleID);
    if (tab != null) { tab.name = moduleName(moduleID); tabs.change(); }
  }
  
  S moduleName(O module) {
    ret dropPrefix("Editing: ", dm_moduleName(module));
  }
  
  void selectModule(O module) {
    if (module == null || dm_isMe(module) || !dm_isVisible()) ret;
    int idx = indexOfWhere(tabs, moduleID := dm_moduleID(module));
    for i over tabs: {
      JComponent c = cast getComponentAtIndex(grid, i);
      if (i == idx) makeBold(c); else makeNonBold(c);
    }
  }
  
  void showModule(O module) { dm_showModule(module); placeUnderMe(module); }
  
  void placeUnderMe(O module) {
    if (!dm_isVisible()) ret;
    Rect r = dm_bounds(module), me = dm_bounds();
    if (me != null && r != null) dm_setBounds(module, me.x, me.y2()+gapBelow, me.w, r.h);
  }
}

Began life as a copy of #1020872