listb.h

Yet another mp3 player, but this time using SVGALib under Linux. The idea was to use a 320x240 disp

/* 
  listb.h  Abstract list class.

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

  This program is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details, www.gnu.org.

  Copyright (C) 2000  Simon Harrison (email smh@[e-mail])
*/


#ifndef LISTB_DOT_H
#define LISTB_DOT_H

#include <stdlib.h>
#include <stdio.h>
#include <string.h>


/*
  This is just a managed string.
*/


class CString {
   char* name;
   int alloc_len;
   public:
   CString( ) : name(NULL),alloc_len(0) {
   }
   virtual ~CString() {
      delete [] name;
   }
   virtual char* GetName(){
      if (name)
        return name;
      else
        return "";
   }
   virtual void SetName(char*);
};


/*
   A scroller object to assist in scrolling the currently selected
   text if it won't fit.
*/


class CScroller {
   int scroll_count;
   int freq;
   int length;
   int max;
   bool up;
   char* text;
   char* out;
   int tlen;
   int scroll_div;
   public :
   CScroller( int width=20) : scroll_div(0),freq(1),scroll_count(0), length(0), up(true), text(NULL) {
      max = width;
   }
   ~CScroller() {
      if (text) delete text;
   }
   void load( char * t, int f ) {
      if (text) delete text;
      if (t) {
         tlen = strlen( t ); 
         text = new char[tlen+1];
         scroll_div = f;
         freq = f;
         if (text) {
            strcpy( text, t );
         }
      }
   }
   char* update( int* sel) {
      if (!text) return "Not loaded";
      if (tlen>max) {
           if (up) {
              if (--scroll_div<=0) {
                 scroll_div = freq;
                 if (++scroll_count==(tlen-max)) {
                    up = false;                    
                    scroll_div = 0;
                    scroll_count--;
                 }
              }
           } else {
              if (++scroll_div>=freq) {
                 scroll_div = 0;
                 if (--scroll_count<0) {
                    up = true;
                    scroll_div = freq;
                    scroll_count++;
                 }
              }
           }
           out = text+scroll_count;
           *sel = scroll_div;
      } else {
        out = NULL;
      }
      return out;
   }
   
};



/*
    List browser class.
    
    Managed interface-independent list browsing.
    
    The Class maintains a window on a (possibly) long list eg files
    in a directory.  The class is independent of the method of display.
    There is support for key input that might traverse the list and
    the capability of selecting a single item from the view list.    
*/


class CListBrowser {
   int PAGE_MAX;    // 10s of units 
   CString* plist;  // current listing 
   CString* ppagelist;
   int npageents;
   int nlistents;   // length of dir listing 
   int cur_page;
   int display_sel;
   int scroll_width;
   int cur_select;
   int scroll_freq;
   char* p;
   int ok;
   bool scroll_on;
   int scroll_max;
   CScroller* scroller;
   public :
   CListBrowser( int page=15 );
   virtual ~CListBrowser() { delete [] ppagelist; delete [] plist;
     delete scroller; }   
   CString* GetPage() { return ppagelist; }
   int GetPageEnts();
   char* GetScrolledSelected( int* offs );
   void ScrollOn( int n, bool b, int freq );
   int GetPageMax() { return PAGE_MAX; }
   int GetSelected() { return display_sel; }
   void up();        // Cursor up    
   void uplots();    // page up      
   void down();      // Cursor down  
   void downlots();  // page down    
   virtual void left();      // cursor left  
   virtual void right();     // Cursor right 
   virtual char* enter();    // enter key (select a file or directory) 
   void DebugDumpPage( CString* p, int n );
   
   protected :
   void SetSelect(int s);
   char* GetListEntry( int i ) { 
      if ((i<nlistents) && (i>=0)) {
         return plist[i].GetName(); 
      } else {
         return "CListBrowserGetListEntry() Error";
      }
   }
   void SetList( CString* list, int n )  { 
      plist = list;  nlistents = n;
   }
   int GetListSelected() { return cur_select; }
   void update( );             // get the new directory listing window 
   int findindex( char* match );  // get the index of an entry given the name 
   int newlisting(int disp);      
   void clean();    // clean the values from the list (to load some more).
};





#endif