//// "$Id: Fl_Roller.cxx,v 1.1.1.1 2003/08/07 21:18:40 jasonk Exp $"//// Roller widget for the Fast Light Tool Kit (FLTK).//// Copyright 1998-1999 by Bill Spitzak and others.//// This library 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.//// This library 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// Library General Public License for more details.//// You should have received a copy of the GNU Library General Public// License along with this library; if not, write to the Free Software// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307// USA.//// Please report all bugs and problems to "fltk-bugs@easysw.com".//// Rapid-App style knob#include <FL/Fl.H>#include <FL/Fl_Roller.H>#include <FL/fl_draw.H>#include <math.h>int Fl_Roller::handle(int event) {  static int ipos;  int newpos = horizontal() ? Fl::event_x() : Fl::event_y();  switch (event) {  case FL_PUSH:    handle_push();    ipos = newpos;    return 1;  case FL_DRAG:    handle_drag(clamp(round(increment(previous_value(),newpos-ipos))));    return 1;  case FL_RELEASE:    handle_release();    return 1;  default:    return 0;  }}void Fl_Roller::draw() {  if (damage()&FL_DAMAGE_ALL) draw_box();  int X = x()+Fl::box_dx(box());  int Y = y()+Fl::box_dy(box());  int W = w()-Fl::box_dw(box())-1;  int H = h()-Fl::box_dh(box())-1;  if (W<=0 || H <=0) return;  int offset = step() ? int(value()/step()) : 0;  const double ARC = 1.5; // 1/2 the number of radians visible  const double delta = .2; // radians per knurl  if (horizontal()) { // horizontal one    // draw shaded ends of wheel:    int h1 = W/4+1; // distance from end that shading starts    fl_color(color()); fl_rectf(X+h1,Y,W-2*h1,H);    for (int i=0; h1; i++) {      fl_color((Fl_Color)(FL_GRAY-i-1));      int h2 = FL_GRAY-i-1 > FL_DARK3 ? 2*h1/3+1 : 0;      fl_rectf(X+h2,Y,h1-h2,H);      fl_rectf(X+W-h1,Y,h1-h2,H);      h1 = h2;    }    if (active_r()) {      // draw ridges:      double junk;      for (double y = -ARC+modf(offset*sin(ARC)/(W/2)/delta,&junk)*delta;;	   y += delta) {	int y1 = int((sin(y)/sin(ARC)+1)*W/2);	if (y1 <= 0) continue; else if (y1 >= W-1) break;	fl_color(FL_DARK3); fl_yxline(X+y1,Y+1,Y+H-1);	if (y < 0) y1--; else y1++;	fl_color(FL_LIGHT1);fl_yxline(X+y1,Y+1,Y+H-1);      }      // draw edges:      h1 = W/8+1; // distance from end the color inverts      fl_color(FL_DARK2);      fl_xyline(X+h1,Y+H-1,X+W-h1);      fl_color(FL_DARK3);      fl_yxline(X,Y+H,Y,X+h1);      fl_xyline(X+W-h1,Y,X+W);      fl_color(FL_LIGHT2);      fl_xyline(X+h1,Y-1,X+W-h1);      fl_yxline(X+W,Y,Y+H,X+W-h1);      fl_xyline(X+h1,Y+H,X);    }  } else { // vertical one    // draw shaded ends of wheel:    int h1 = H/4+1; // distance from end that shading starts    fl_color(color()); fl_rectf(X,Y+h1,W,H-2*h1);    for (int i=0; h1; i++) {      fl_color((Fl_Color)(FL_GRAY-i-1));      int h2 = FL_GRAY-i-1 > FL_DARK3 ? 2*h1/3+1 : 0;      fl_rectf(X,Y+h2,W,h1-h2);      fl_rectf(X,Y+H-h1,W,h1-h2);      h1 = h2;    }    if (active_r()) {      // draw ridges:      double junk;      for (double y = -ARC+modf(offset*sin(ARC)/(H/2)/delta,&junk)*delta;	   ; y += delta) {	int y1 = int((sin(y)/sin(ARC)+1)*H/2);	if (y1 <= 0) continue; else if (y1 >= H-1) break;	fl_color(FL_DARK3); fl_xyline(X+1,Y+y1,X+W-1);	if (y < 0) y1--; else y1++;	fl_color(FL_LIGHT1);fl_xyline(X+1,Y+y1,X+W-1);      }      // draw edges:      h1 = H/8+1; // distance from end the color inverts      fl_color(FL_DARK2);      fl_yxline(X+W-1,Y+h1,Y+H-h1);      fl_color(FL_DARK3);      fl_xyline(X+W,Y,X,Y+h1);      fl_yxline(X,Y+H-h1,Y+H);      fl_color(FL_LIGHT2);      fl_yxline(X,Y+h1,Y+H-h1);      fl_xyline(X,Y+H,X+W,Y+H-h1);      fl_yxline(X+W,Y+h1,Y);    }  }}Fl_Roller::Fl_Roller(int X,int Y,int W,int H,const char* L)  : Fl_Valuator(X,Y,W,H,L) {  box(FL_UP_FRAME);  step(1,1000);}//// End of "$Id: Fl_Roller.cxx,v 1.1.1.1 2003/08/07 21:18:40 jasonk Exp $".//