#include <TGButton.h>
#include <TGCanvas.h>
#include <TGListTree.h>
#include <TApplication.h>


class ListTree {

protected:
  TGMainFrame *fMain;     // main frame
  TGListTree *fList;
  TGListTreeItem *fTop;
  Int_t fCounter;

public:
  ListTree();
  virtual ~ListTree() { delete fMain; }
  void Add();
  void Sort();
   
  ClassDef(ListTree, 0);
};


ListTree::ListTree() : fCounter(10)
{

  // Main test window.

  fMain = new TGMainFrame(gClient->GetRoot(), 10, 10, kVerticalFrame);

  // recusively delete all subframes on exit
  fMain->SetCleanup(kDeepCleanup);

  // terminate ROOT session when window is closed
  fMain->Connect("CloseWindow()", "TApplication", gApplication, "Terminate()");
  fMain->DontCallClose();

  fCanvas = new TGCanvas(fMain, 500, 300);
  fList = new TGListTree(fCanvas, kVerticalFrame);
  TGLayoutHints *lo = new TGLayoutHints(kLHintsExpandX | kLHintsExpandY | kLHintsTop);
  fMain->AddFrame(fCanvas,lo);

  TGTextButton *add = new TGTextButton(fMain,"Add");
  lo = new TGLayoutHints(kLHintsExpandX | kLHintsBottom);
  fMain->AddFrame(add,lo);
  add->Connect("Clicked()","ListTree",this,"Add()");
  
  TGTextButton *sort = new TGTextButton(fMain,"Sort");
  lo = new TGLayoutHints(kLHintsExpandX | kLHintsBottom);
  fMain->AddFrame(sort,lo);
  sort->Connect("Clicked()","ListTree",this,"Sort()");
  
  fTop = fList->AddItem(0,"Top");
  fList->OpenItem(fTop);

  fMain->MapSubwindows();
  fMain->Resize();

  // set minimum width, height
  fMain->SetWMSizeHints(fMain->GetDefaultWidth(), fMain->GetDefaultHeight(),
			1000, 1000, 0, 0);
  fMain->SetWindowName("Text Entries");
  fMain->MapRaised();
}

void ListTree::Add()
{

  fList->AddItem(fTop,Form("%d",fCounter--));
  gClient->NeedRedraw(fList,kTRUE);
  fList->ClearViewPort();

}

void ListTree::Sort()
{

  fList->SortChildren(fTop);
  gClient->NeedRedraw(fList,kTRUE);
  fList->ClearViewPort();

}

void listTree()
{
  // Main program.

  new ListTree();
}