void fildir(){
//
// This macro displays the ROOT Directory data structure
//Author: Rene Brun
TCanvas *c1 = new TCanvas("c1","ROOT FilDir description",700,900);
c1->Range(1,1,19,24.5);
TPaveLabel *title = new TPaveLabel(4,23,16,24.2,"ROOT File/Directory/Key description");
title->SetFillColor(16);
title->Draw();
Int_t keycolor = 42;
Int_t dircolor = 21;
Int_t objcolor = 46;
TPaveText *file = new TPaveText(2,19,6,22);
file->SetFillColor(39);
file->Draw();
file->SetTextSize(0.04);
file->AddText("TFile");
file->AddText("Header");
TArrow *arrow = new TArrow(6,20.5,17,20.5,0.02,"|>");
arrow->SetFillStyle(1001);
arrow->SetLineWidth(2);
arrow->Draw();
TPaveText *free1 = new TPaveText(8,20,11,21);
free1->SetFillColor(18);
free1->Draw();
free1->AddText("First:Last");
TPaveText *free2 = new TPaveText(12,20,15,21);
free2->SetFillColor(18);
free2->Draw();
free2->AddText("First:Last");
TText *tfree = new TText(6.2,21.2,"fFree = TList of free blocks");
tfree->SetTextSize(0.02);
tfree->Draw();
TText *tkeys = new TText(5.2,18.2,"fKeys = TList of Keys");
tkeys->SetTextSize(0.02);
tkeys->Draw();
TText *tmemory = new TText(3.2,15.2,"fListHead = TList of Objects in memory");
tmemory->SetTextSize(0.02);
tmemory->Draw();
arrow->DrawArrow(5,17,17,17,0.02,"|>");
TLine *line = new TLine(5,19,5,17);
line->SetLineWidth(2);
line->Draw();
TPaveText *key0 = new TPaveText(7,16,10,18);
key0->SetTextSize(0.04);
key0->SetFillColor(keycolor);
key0->AddText("Key 0");
key0->Draw();
TPaveText *key1 = new TPaveText(12,16,15,18);
key1->SetTextSize(0.04);
key1->SetFillColor(keycolor);
key1->AddText("Key 1");
key1->Draw();
line->DrawLine(3,19,3,14);
line->DrawLine(3,14,18,14);
TPaveText *obj0 = new TPaveText(5,13,8,15);
obj0->SetFillColor(objcolor);
obj0->AddText("Object");
obj0->Draw();
TPaveText *dir1 = new TPaveText(10,13,13,15);
dir1->SetFillColor(dircolor);
dir1->AddText("SubDir");
dir1->Draw();
TPaveText *obj1 = new TPaveText(15,13,18,15);
obj1->SetFillColor(objcolor);
obj1->AddText("Object");
obj1->Draw();
arrow->DrawArrow(12,11,17,11,0.015,"|>");
arrow->DrawArrow(11,9,17,9,0.015,"|>");
line->DrawLine(12,13,12,11);
line->DrawLine(11,13,11,9);
TPaveText *key2 = new TPaveText(14,10.5,16,11.5);
key2->SetFillColor(keycolor);
key2->AddText("Key 0");
key2->Draw();
TPaveText *obj2 = new TPaveText(14,8.5,16,9.5);
obj2->SetFillColor(objcolor);
obj2->AddText("Object");
obj2->Draw();
TLine *ldot = new TLine(10,15,2,11);
ldot->SetLineStyle(2);
ldot->Draw();
ldot->DrawLine(13,15,8,11);
ldot->DrawLine(13,13,8,5);
TPaveText *dirdata = new TPaveText(2,5,8,11);
dirdata->SetTextAlign(12);
dirdata->SetFillColor(dircolor);
dirdata->Draw();
dirdata->SetTextSize(0.015);
dirdata->AddText("fModified: True if directory is modified");
dirdata->AddText("fWritable: True if directory is writable");
dirdata->AddText("fDatimeC: Creation Date/Time");
dirdata->AddText("fDatimeM: Last mod Date/Time");
dirdata->AddText("fNbytesKeys: Number of bytes of key");
dirdata->AddText("fNbytesName : Header length up to title");
dirdata->AddText("fSeekDir: Start of Directory on file");
dirdata->AddText("fSeekParent: Start of Parent Directory");
dirdata->AddText("fSeekKeys: Pointer to Keys record");
TPaveText *keydata = new TPaveText(10,2,17,7);
keydata->SetTextAlign(12);
keydata->SetFillColor(keycolor);
keydata->Draw();
ldot->DrawLine(14,11.5,10,7);
ldot->DrawLine(16,11.5,17,7);
keydata->SetTextSize(0.015);
keydata->AddText("fNbytes: Size of compressed Object");
keydata->AddText("fObjLen: Size of uncompressed Object");
keydata->AddText("fDatime: Date/Time when written to store");
keydata->AddText("fKeylen: Number of bytes for the key");
keydata->AddText("fCycle : Cycle number");
keydata->AddText("fSeekKey: Pointer to Object on file");
keydata->AddText("fSeekPdir: Pointer to directory on file");
keydata->AddText("fClassName: 'TKey'");
keydata->AddText("fName: Object name");
keydata->AddText("fTitle: Object Title");
}