    // @(#)root/gui:$Name:  $:$Id: TGComboBox.cxx,v 1.21 2004/07/07 10:17:20 brun Exp $
    // Author: Fons Rademakers   13/01/98

    /*************************************************************************
     * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
     * All rights reserved.                                                  *
     *                                                                       *
     * For the licensing terms see $ROOTSYS/LICENSE.                         *
     * For the list of contributors see $ROOTSYS/README/CREDITS.             *
     *************************************************************************/
    /**************************************************************************

        This source is based on Xclass95, a Win95-looking GUI toolkit.
        Copyright (C) 1996, 1997 David Barth, Ricky Ralston, Hector Peraza.

        Xclass95 is free software; you can redistribute it and/or
        modify it under the terms of the GNU Library General Public
        License as published by the Free Software Foundation; either
        version 2 of the License, or (at your option) any later version.

    **************************************************************************/

    //////////////////////////////////////////////////////////////////////////
    //                                                                      //
    // TGComboBox, TGComboBoxPopup                                          //
    //                                                                      //
    // A combobox (also known as a drop down listbox) allows the selection  //
    // of one item out of a list of items. The selected item is visible in  //
    // a little window. To view the list of possible items one has to click //
    // on a button on the right of the little window. This will drop down   //
    // a listbox. After selecting an item from the listbox the box will     //
    // disappear and the newly selected item will be shown in the little    //
    // window.                                                              //
    //                                                                      //
    // The TGComboBox is user callable. The TGComboBoxPopup is a service    //
    // class of the combobox.                                               //
    //                                                                      //
    // Selecting an item in the combobox will generate the event:           //
    // kC_COMMAND, kCM_COMBOBOX, combobox id, item id.                      //
    //                                                                      //
    //////////////////////////////////////////////////////////////////////////

    #include "TGComboBox.h"
    #include "TGScrollBar.h"
    #include "TGPicture.h"
    #include "TGResourcePool.h"
    #include "Riostream.h"
    #include "TGTextEntry.h"

    ClassImp(TGComboBoxPopup)
    ClassImp(TGComboBox)

    ClassImp(TGLineStyleComboBox)
    ClassImp(TGLineWidthComboBox)
    ClassImp(TGFontTypeComboBox)

    //______________________________________________________________________________
    TGComboBoxPopup::TGComboBoxPopup(const TGWindow *p, UInt_t w, UInt_t h,
                                     UInt_t options, ULong_t back) :
       TGCompositeFrame (p, w, h, options, back)
    {
       // Create a combo box popup frame.

       SetWindowAttributes_t wattr;

       wattr.fMask = kWAOverrideRedirect | kWASaveUnder |
                     kWABorderPixel      | kWABorderWidth;
       wattr.fOverrideRedirect = kTRUE;
       wattr.fSaveUnder = kTRUE;
       wattr.fBorderPixel = fgBlackPixel;
       wattr.fBorderWidth = 1;
       gVirtualX->ChangeWindowAttributes(fId, &wattr);

       AddInput(kStructureNotifyMask);
    }

    //______________________________________________________________________________
    Bool_t TGComboBoxPopup::HandleButton(Event_t *event)
    {
       // Handle mouse button event in combo box popup.

       if (event->fType == kButtonPress && event->fCode == kButton1)
          EndPopup();
       return kTRUE;
    }

    //______________________________________________________________________________
    void TGComboBoxPopup::EndPopup()
    {
       // Ungrab pointer and unmap popup window.

       gVirtualX->GrabPointer(0, 0, 0, 0, kFALSE);
       UnmapWindow();
    }

    //______________________________________________________________________________
    void TGComboBoxPopup::PlacePopup(Int_t x, Int_t y, UInt_t w, UInt_t h)
    {
       // Popup combo box popup window at the specified place.

       Int_t  rx, ry;
       UInt_t rw, rh;

       // Parent is root window for the popup:
       gVirtualX->GetWindowSize(fParent->GetId(), rx, ry, rw, rh);

       if (x < 0) x = 0;
       if (x + fWidth > rw) x = rw - fWidth;
       if (y < 0) y = 0;
       if (y + fHeight > rh) y = rh - fHeight;

       MoveResize(x, y, w, h);
       MapSubwindows();
       Layout();
       MapRaised();

       gVirtualX->GrabPointer(fId, kButtonPressMask | kButtonReleaseMask |
                              kPointerMotionMask, kNone,
                              fClient->GetResourcePool()->GetGrabCursor());

       fClient->WaitForUnmap(this);
       EndPopup();
    }

    //______________________________________________________________________________
     TGComboBox::TGComboBox(const TGWindow *p, Int_t id, UInt_t options,
                           ULong_t back) :
       TGCompositeFrame (p, 10, 10, options | kOwnBackground, back)
    {
       // Create a combo box widget.

       fWidgetId  = id;
       fMsgWindow = p;
       fTextEntry = 0;

       fSelEntry = new TGTextLBEntry(this, new TGString(""), 0);
       fSelEntry->ChangeOptions(fSelEntry->GetOptions() | kOwnBackground);

       AddFrame(fSelEntry, fLhs = new TGLayoutHints(kLHintsLeft |
                                                    kLHintsExpandY | kLHintsExpandX));
       Init();
    }

    //______________________________________________________________________________
     TGComboBox::TGComboBox(const TGWindow *p, const char *text, Int_t id,
                           UInt_t options, ULong_t back) :
                TGCompositeFrame (p, 10, 10, options | kOwnBackground, back)
    {
       //

       fWidgetId  = id;
       fMsgWindow = p;
       fSelEntry = 0;

       fTextEntry = new TGTextEntry(this, text, id);
       fTextEntry->SetFrameDrawn(kFALSE);

       AddFrame(fTextEntry, fLhs = new TGLayoutHints(kLHintsLeft |
                                                    kLHintsExpandY | kLHintsExpandX));
       Init();
    }

    //______________________________________________________________________________
     TGComboBox::~TGComboBox()
    {
       // Delete a combo box widget.

       delete fDDButton;
       delete fSelEntry;
       delete fTextEntry;
       delete fListBox;
       delete fComboFrame;
       delete fLhs;
       delete fLhb;
       delete fLhdd;
    }

    //______________________________________________________________________________
     void TGComboBox::Init()
    {
       // init

       fBpic = fClient->GetPicture("arrow_down.xpm");

       if (!fBpic)
          Error("TGComboBox", "arrow_down.xpm not found");

       fDDButton = new TGScrollBarElement(this, fBpic, kDefaultScrollBarWidth,
                                          kDefaultScrollBarWidth, kRaisedFrame);

       AddFrame(fDDButton, fLhb = new TGLayoutHints(kLHintsRight |
                                                    kLHintsExpandY));

       fComboFrame = new TGComboBoxPopup(fClient->GetDefaultRoot(), 100, 100, kVerticalFrame);

       fListBox = new TGListBox(fComboFrame, fWidgetId, kChildFrame);
       fListBox->Resize(100, 100);
       fListBox->Associate(this);
       fListBox->GetScrollBar()->GrabPointer(kFALSE); // combobox will do a pointergrab

       fComboFrame->AddFrame(fListBox, fLhdd = new TGLayoutHints(kLHintsExpandX |
                                                                 kLHintsExpandY));
       fComboFrame->MapSubwindows();
       fComboFrame->Resize(fComboFrame->GetDefaultSize());

       gVirtualX->GrabButton(fId, kButton1, kAnyModifier, kButtonPressMask |
                            kButtonReleaseMask | kPointerMotionMask, kNone, kNone);

       // Drop down listbox of combo box should react to pointer motion
       // so it will be able to Activate() (i.e. highlight) the different
       // items when the mouse crosses.
       fListBox->GetContainer()->AddInput(kButtonPressMask | kButtonReleaseMask |
                                          kPointerMotionMask);
    }

    //______________________________________________________________________________
     void TGComboBox::DrawBorder()
    {
       // Draw border of combo box widget.

       switch (fOptions & (kSunkenFrame | kRaisedFrame | kDoubleBorder)) {
          case kSunkenFrame | kDoubleBorder:
             gVirtualX->DrawLine(fId, GetShadowGC()(), 0, 0, fWidth-2, 0);
             gVirtualX->DrawLine(fId, GetShadowGC()(), 0, 0, 0, fHeight-2);
             gVirtualX->DrawLine(fId, GetBlackGC()(), 1, 1, fWidth-3, 1);
             gVirtualX->DrawLine(fId, GetBlackGC()(), 1, 1, 1, fHeight-3);

             gVirtualX->DrawLine(fId, GetHilightGC()(), 0, fHeight-1, fWidth-1, fHeight-1);
             gVirtualX->DrawLine(fId, GetHilightGC()(), fWidth-1, fHeight-1, fWidth-1, 0);
             gVirtualX->DrawLine(fId, GetBckgndGC()(),  1, fHeight-2, fWidth-2, fHeight-2);
             gVirtualX->DrawLine(fId, GetBckgndGC()(),  fWidth-2, 1, fWidth-2, fHeight-2);
             break;

          default:
             TGCompositeFrame::DrawBorder();
             break;
       }
    }

    //______________________________________________________________________________
     void TGComboBox::SetTopEntry(TGLBEntry *e, TGLayoutHints *lh)
    {
       // Set a new combo box value (normally update of text string in
       // fSelEntry is done via fSelEntry::Update()).

       if (!fSelEntry) return;

       RemoveFrame(fSelEntry);
       fSelEntry->DestroyWindow();
       delete fSelEntry;
       delete fLhs;
       fSelEntry = e;
       fLhs = lh;
       AddFrame(fSelEntry, fLhs);
       Layout();
    }

    //______________________________________________________________________________
     void TGComboBox::Select(Int_t id)
    {
       // Make the selected item visible in the combo box window.

       TGLBEntry *e;

       e = fListBox->Select(id);
       if (e) {
          if (fSelEntry) {
             fSelEntry->Update(e);
             Layout();
             Selected(fWidgetId, id);
             Selected(id);
          }
       }
    }

    //______________________________________________________________________________
     Bool_t TGComboBox::HandleButton(Event_t *event)
    {
       // Handle mouse button events in the combo box.

       if (event->fType == kButtonPress) {
          Window_t child = (Window_t)event->fUser[0];  // fUser[0] = child window

          if ( child == fDDButton->GetId()) {
             fDDButton->SetState(kButtonDown);

             if (fTextEntry && (child == fTextEntry->GetId())) {
                return fTextEntry->HandleButton(event);
             }
             int      ax, ay;
             Window_t wdummy;

             gVirtualX->TranslateCoordinates(fId, fComboFrame->GetParent()->GetId(),
                                             0, fHeight, ax, ay, wdummy);

             fComboFrame->PlacePopup(ax, ay, fWidth-2, fComboFrame->GetDefaultHeight());
             fDDButton->SetState(kButtonUp);

          } else if (fTextEntry) {
             return fTextEntry->HandleButton(event);
          }
       }
       return kTRUE;
    }

    //______________________________________________________________________________
     Bool_t TGComboBox::HandleDoubleClick(Event_t *event)
    {
       // handle double click in text entry

       return fTextEntry ? fTextEntry->HandleDoubleClick(event) : kTRUE;
    }

    //______________________________________________________________________________
     Bool_t TGComboBox::HandleMotion(Event_t *event)
    {
       // handle pointer motion in text entry

       return fTextEntry ? fTextEntry->HandleMotion(event) : kTRUE;
    }

    //______________________________________________________________________________
     Bool_t TGComboBox::HandleSelection(Event_t *event)
    {
       // handle selection  in text entry

       return fTextEntry ? fTextEntry->HandleSelection(event) : kTRUE;
    }

    //______________________________________________________________________________
     Bool_t TGComboBox::HandleSelectionRequest(Event_t *event)
    {
       // handle selection request in text entry

       return fTextEntry ? fTextEntry->HandleSelectionRequest(event) : kTRUE;
    }

    //______________________________________________________________________________
     Bool_t TGComboBox::ProcessMessage(Long_t msg, Long_t, Long_t parm2)
    {
       // Process messages generated by the listbox and forward
       // messages to the combobox message handling window. Parm2 contains
       // the id of the selected listbox entry.

       TGLBEntry *e;

       switch (GET_MSG(msg)) {
          case kC_COMMAND:
             switch (GET_SUBMSG(msg)) {
                case kCM_LISTBOX:
                   e = fListBox->GetSelectedEntry();
                   if (fSelEntry) {
                      fSelEntry->Update(e);
                   } else if (fTextEntry &&
                              e->InheritsFrom(TGTextLBEntry::Class())) {
                      TGTextLBEntry *te = (TGTextLBEntry*)e;
                      fTextEntry->SetText(te->GetText()->GetString());
                   }
                   Layout();
                   fComboFrame->EndPopup();
                   fDDButton->SetState(kButtonUp);
                   SendMessage(fMsgWindow, MK_MSG(kC_COMMAND, kCM_COMBOBOX),
                               fWidgetId, parm2);
                   if (e->InheritsFrom(TGTextLBEntry::Class())) {
                      const char *text;
                      text = ((TGTextLBEntry*)e)->GetText()->GetString();
                      Selected(text);
                   }
                   Selected(fWidgetId, (Int_t)parm2);
                   Selected((Int_t)parm2);
                   break;
             }
             break;

          default:
             break;
       }
       return kTRUE;
    }

    //______________________________________________________________________________
     void TGComboBox::Selected(Int_t widgetId, Int_t id)
    {
       // Emit signal.

       Long_t args[2];

       args[0] = widgetId;
       args[1] = id;

       Emit("Selected(Int_t,Int_t)", args);
    }

    //______________________________________________________________________________
     void TGComboBox::SavePrimitive(ofstream &out, Option_t *option)
    {
       // Save a combo box widget as a C++ statement(s) on output stream out.

       if (fBackground != GetDefaultFrameBackground()) SaveUserColor(out, option);

       out << endl << "   // combo box" << endl;
       out << "   TGComboBox *";

       if (!fTextEntry) {
          out << GetName() << " = new TGComboBox(" << fParent->GetName() << "," << fWidgetId;
       } else {
          out << GetName() << " = new TGComboBox(" << fParent->GetName() << ",";
           out << '\"' <<  fTextEntry->GetText() << '\"' << "," <<fWidgetId;
       }

       if (fBackground == GetWhitePixel()) {
          if (GetOptions() == (kHorizontalFrame | kSunkenFrame | kDoubleBorder)) {
             out <<");" << endl;
          } else {
             out << "," << GetOptionString() << ");" << endl;
          }
       } else {
          out << "," << GetOptionString() << ",ucolor);" << endl;
       }

       TGTextLBEntry *b;
       TGFrameElement *el;
       TGListBox *lb = GetListBox();

       TIter next(((TGLBContainer *)lb->GetContainer())->GetList());

       while ((el = (TGFrameElement *) next())) {
          b = (TGTextLBEntry *) el->fFrame;
          out << "   " << GetName() << "->AddEntry(";
          b->SavePrimitive(out, option);
          out <<  ");" << endl;
       }

       out << "   " << GetName() << "->Resize(" << GetWidth()  << ","
           << GetHeight() << ");" << endl;
       out << "   " << GetName() << "->Select(" << GetSelected() << ");" << endl;
    }

    //______________________________________________________________________________
    TGLineStyleComboBox::TGLineStyleComboBox(const TGWindow *p, Int_t id,
                                             UInt_t options, Pixel_t back)
       : TGComboBox(p, id, options, back)
    {
       // Create a line style combo box.

       SetTopEntry(new TGLineLBEntry(this, 0),
                   new TGLayoutHints(kLHintsLeft | kLHintsExpandY | kLHintsExpandX));
       fSelEntry->ChangeOptions(fSelEntry->GetOptions() | kOwnBackground);

       for (int i = 1; i <= 4; i++)
          AddEntry(new TGLineLBEntry(GetListBox()->GetContainer(), i, Form("%d",i), 0, i),
                   new TGLayoutHints(kLHintsTop | kLHintsExpandX));
       fComboFrame->SetHeight(25);
       Select(1);  // to have first entry selected
    }

    //______________________________________________________________________________
    TGLineWidthComboBox::TGLineWidthComboBox(const TGWindow *p, Int_t id,
                                             UInt_t options, Pixel_t back)
       : TGComboBox(p, id, options, back)
    {
       // Create a line width combo box.

       SetTopEntry(new TGLineLBEntry(this,0),
                   new TGLayoutHints(kLHintsLeft | kLHintsExpandY | kLHintsExpandX));
       fSelEntry->ChangeOptions(fSelEntry->GetOptions() | kOwnBackground);

       for (int i = 1; i < 16; i++)
          AddEntry(new TGLineLBEntry(GetListBox()->GetContainer(), i, Form("%d",i), i, 0),
                   new TGLayoutHints(kLHintsTop | kLHintsExpandX));
       Select(1);  // to have first entry selected
    }

    static const char *fonts[][2] = {    //   unix name,     name
       { "",                                           ""                         }, //not used
       { "-*-times-medium-i-*-*-12-*-*-*-*-*-*-*",     "1. times italic"          },
       { "-*-times-bold-r-*-*-12-*-*-*-*-*-*-*",       "2. times bold"            },
       { "-*-times-bold-i-*-*-12-*-*-*-*-*-*-*",       "3. times bold italic"     },
       { "-*-helvetica-medium-r-*-*-12-*-*-*-*-*-*-*", "4. helvetica"             },
       { "-*-helvetica-medium-o-*-*-12-*-*-*-*-*-*-*", "5. helvetica italic"      },
       { "-*-helvetica-bold-r-*-*-12-*-*-*-*-*-*-*",   "6. helvetica bold"        },
       { "-*-helvetica-bold-o-*-*-12-*-*-*-*-*-*-*",   "7. helvetica bold italic" },
       { "-*-courier-medium-r-*-*-12-*-*-*-*-*-*-*",   "8. courier"               },
       { "-*-courier-medium-o-*-*-12-*-*-*-*-*-*-*",   "9. courier italic"        },
       { "-*-courier-bold-r-*-*-12-*-*-*-*-*-*-*",     "10. courier bold"         },
       { "-*-courier-bold-o-*-*-12-*-*-*-*-*-*-*",     "11. courier bold italic"  },
       { "-*-symbol-medium-r-*-*-12-*-*-*-*-*-*-*",    "12. symbol"               },
       { "-*-times-medium-r-*-*-12-*-*-*-*-*-*-*",     "13. times"                },
       { 0, 0}
    };

    //______________________________________________________________________________
    TGFontTypeComboBox::TGFontTypeComboBox(const TGWindow *p, Int_t id,
                                           UInt_t options, Pixel_t back) :
       TGComboBox(p, id, options, back)
    {
       // Create a text font combo box.

       int noFonts = 0;

       for (int i = 1; fonts[i][0] != 0 && noFonts < kMaxFonts; i++) {

          fFonts[noFonts] = gVirtualX->LoadQueryFont(fonts[i][0]);

          if (fFonts[noFonts] == 0)
             fFonts[noFonts] = TGTextLBEntry::GetDefaultFontStruct();

          GCValues_t gval;
          gval.fMask = kGCFont;
          gval.fFont = gVirtualX->GetFontHandle(fFonts[noFonts]);

          AddEntry(new TGTextLBEntry(GetListBox()->GetContainer(),
                   new TGString(fonts[i][1]), i,
                   fClient->GetGC(&gval, kTRUE)->GetGC(), fFonts[noFonts]),
                   new TGLayoutHints(kLHintsTop | kLHintsLeft | kLHintsExpandX));
          noFonts++;
       }

       if (noFonts < kMaxFonts - 1)
          ;
       fFonts[noFonts] = 0;
       Select(1);  // to have first entry selected
    }

    //______________________________________________________________________________
    TGFontTypeComboBox::~TGFontTypeComboBox()
    {
       // Text font combo box dtor.

       for (int i = 0; i < kMaxFonts && fFonts[i] != 0; i++)
          gVirtualX->DeleteFont(fFonts[i]);
    }