// $Id$
//-----------------------------------------------------------------------
//       The GSI Online Offline Object Oriented (Go4) Project
//         Experiment Data Processing at EE department, GSI
//-----------------------------------------------------------------------
// Copyright (C) 2000- GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
//                     Planckstr. 1, 64291 Darmstadt, Germany
// Contact:            http://go4.gsi.de
//-----------------------------------------------------------------------
// This software can be used under the license agreements as stated
// in Go4License.txt file which is part of the distribution.
//-----------------------------------------------------------------------

#include "TGo4LabelPainter.h"

#include "TROOT.h"
#include "TVirtualPad.h"

TGo4LabelPainter::TGo4LabelPainter() :
   TNamed(),
   fdX0(0),
   fdY0(0),
   fbIsLabStreamed(kTRUE)
{
   InitAttributes();
}

TGo4LabelPainter::TGo4LabelPainter(const char *name, const char *title) :
   TNamed(name, title ? title : "Go4 LabelPainter"),
   fdX0(0),
   fdY0(0),
   fbIsLabStreamed(kFALSE)
{
   InitAttributes();
}

void TGo4LabelPainter::InitAttributes()
{
   SetBit(kMustCleanup);
   fdWidth = 0.25;
   fdHeight = 0.22;
   SetCaption("Empty label");
   SetTextAlign(12); // left and central aligned
   //SetTextSize(0.03); // % of pad height
   SetTextSize(0); // this will let root scale fontsize depending on label frame
   SetTextFont(102); // proportional font for alignment of equations
   SetTextColor(GetLineColor());
}

TGo4LabelPainter::~TGo4LabelPainter()
{
   if (fxLabel) {
      delete fxLabel;
      fxLabel = nullptr;
   }
}

void TGo4LabelPainter::PaintLabel(Option_t *opt)
{
   if(!gPad) return;
   Double_t xrange = (gPad->GetUxmax()-gPad->GetUxmin());
   Double_t yrange = (gPad->GetUymax()-gPad->GetUymin());
   if(!CheckLabel()) {
      // label was deleted by us or by root:
      if(fdX0 == 0)
         fdX0 = xrange/2; // default: place at x center
      if(fdY0 == 0)
         fdY0 = yrange/2; // default: place at y center
      // JAM: these initial coordinates can be problematic if assigned histogram is not yet drawn completely...
      fxLabel=CreateCurrentLabel(fdX0,fdY0);
      fxLabel->AppendPad(opt); // only append to pad if not already there
   } else {
      // label is existing:
      if (!gPad->GetListOfPrimitives()->FindObject(fxLabel))
         fxLabel->AppendPad(opt); // label was cleared from pad, we redraw it

      // JAM: catch here the case that label box was drawn with unsuited coordinates:
      if(((fxLabel->GetX2()- fxLabel->GetX1())<0.05*xrange) || (fxLabel->GetY2()- fxLabel->GetY1())<0.05*yrange)
        {
          Double_t x0 = xrange/2;
          Double_t y0 = yrange/2;
          Double_t xmax = 0.;
          Double_t ymax = 0.;
          LabelCoords(x0,y0,xmax,ymax);
          fxLabel->SetX1(x0);
          fxLabel->SetX2(xmax);
          fxLabel->SetY1(y0);
          fxLabel->SetY2(ymax);
          //printf("TGo4LabelPainter::PaintLabel corrected label coords to: (%f %f) (%f %f)",x0,y0,xmax,ymax);
        }

      fxLabel->SetLineColor(GetLineColor());
      fxLabel->Clear(); // remove old text lines
   }
   fxLabel->AddText(fxCaption.Data());
   fxLabel->AddText(" "); // dummy for automatic position of next line
   fxLabel->AddLine(0,0,0,0);
}

void TGo4LabelPainter::UnPaintLabel(Option_t *opt)
{
   gROOT->GetListOfCanvases()->RecursiveRemove(fxLabel);

   // we do not delete label, but restore graphics properties though invisible
   TString option=opt;
   if(option.Contains("reset")) {
      // case of reset option: discard old label geometry if
      if(CheckLabel()) {
         delete fxLabel;
         fxLabel = nullptr;
      }
   }
}

void TGo4LabelPainter::RePaintLabel(Option_t *opt)
{
   if (fxLabel)
      fxLabel->Paint(opt);
}

void TGo4LabelPainter::DisplayToFront(Option_t *opt)
{
   if(fxLabel)
      fxLabel->Pop();
}

TGo4Label* TGo4LabelPainter::CreateCurrentLabel(Double_t x, Double_t y)
{
   if(!gPad) return nullptr;
   // buffer external variables, since LabelCoords will change them
   Double_t x0 = x, y0 = y, xmax = 0, ymax = 0;
   LabelCoords(x0,y0,xmax,ymax);
   auto label = new TGo4Label(x0,y0,xmax,ymax);
   label->SetOwner(this);
   TAttText::Copy(*label);
   TAttLine::Copy(*label);
   TAttFill::Copy(*label);
   return label;
}

Bool_t TGo4LabelPainter::CheckLabel()
{
   if (fbIsLabStreamed && fxLabel) {
      // case of label was streamed from file: not yet in cleanup list!
      fxLabel->SetOwner(this);
      fbIsLabStreamed = kFALSE;
      return kTRUE;
   }

   if (TGo4Label::fxLastDeleted == fxLabel) {
      // our label was deleted by user mouse menu (or pad clear!)just before
      TGo4Label::fxLastDeleted = nullptr;
      fxLabel = nullptr; // reset reference, will re-create label on next paint
      return kFALSE;
   }

   return fxLabel != nullptr;
}

void TGo4LabelPainter::LabelCoords(Double_t &xmin, Double_t &ymin, Double_t &xmax, Double_t &ymax)
{
   Double_t xpmin = gPad->GetUxmin();
   Double_t xpmax = gPad->GetUxmax();
   Double_t ypmin = gPad->GetUymin();
   Double_t ypmax = gPad->GetUymax(); // this delivers pad coordinates
   Double_t dx = (xpmax - xpmin);
   Double_t dy = (ypmax - ypmin);
   Double_t width = fdWidth * dx;
   Double_t height = fdHeight * dy; // width is in pad coordinates
   xmax = gPad->XtoPad(xmin) + width;
   ymax = gPad->YtoPad(ymin) + height; // calculate label geometry in pad coordinates
   xmax = gPad->PadtoX(xmax);
   ymax = gPad->PadtoY(ymax); // back to axis coordinates for initial pavetext
}

Double_t TGo4LabelPainter::GetLabelXlo()
{
   return fxLabel ? fxLabel->GetX1() : 0;
}

Double_t TGo4LabelPainter::GetLabelYlo()
{
   return fxLabel ? fxLabel->GetY1() : 0;
}

Double_t TGo4LabelPainter::GetLabelXup()
{
   return fxLabel ? fxLabel->GetX2() : 0;
}

Double_t TGo4LabelPainter::GetLabelYup()
{
   return fxLabel ? fxLabel->GetY2() : 0;
}

///////////// treat painting of the text label: ///////////

const void *TGo4Label::fxLastDeleted = nullptr;


void TGo4Label::Paint(Option_t *opt)
{
   if (!gPad)
      return;

   if (fxOwner)
      TPaveText::Paint(opt);

   // suppress painting of labels without owner. This case
   // happens after insert canvas in go4 (separate cloning
   // of lists of primitive members), thus leading to a
   // second "ghost label" for markers and conditions
}

///////////// use this to pop the label to front whenever touched
void TGo4Label::ExecuteEvent(Int_t event, Int_t px, Int_t py)
{
   if(!gPad) return;
   TPaveText::ExecuteEvent(event,px,py);
   if(event == kButton1Up)  {
      TGo4LabelPainter* painter = dynamic_cast<TGo4LabelPainter*>(fxOwner);
      if(painter)
         painter->DisplayToFront();
   }
}

//////////////////////////////////////////////////////////

const void *TGo4LabelConnector::fxLastDeleted = nullptr;

///////////// treat painting of the text label connector:
void TGo4LabelConnector::Paint(Option_t *opt)
{
   if (!gPad)
      return;
   if (fxOwner)
      TLine::Paint(opt);
   // suppress painting of label connectors without owner. This case
   // happens after insert canvas in go4 (separate cloning
   // of lists of primitive members), thus leading to a
   // second "ghost label connector" for markers
}
/////////////////////////////////////////////////////////