1 //
2 // "$Id: Fl_Valuator.cxx 5190 2006-06-09 16:16:34Z mike $"
3 //
4 // Valuator widget for the Fast Light Tool Kit (FLTK).
5 //
6 // Copyright 1998-2005 by Bill Spitzak and others.
7 //
8 // This library is free software; you can redistribute it and/or
9 // modify it under the terms of the GNU Library General Public
10 // License as published by the Free Software Foundation; either
11 // version 2 of the License, or (at your option) any later version.
12 //
13 // This library is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 // Library General Public License for more details.
17 //
18 // You should have received a copy of the GNU Library General Public
19 // License along with this library; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
21 // USA.
22 //
23 // Please report all bugs and problems on the following page:
24 //
25 // http://www.fltk.org/str.php
26 //
27
28 // Base class for sliders and all other one-value "knobs"
29
30 #include <FL/Fl.H>
31 #include <FL/Fl_Valuator.H>
32 #include <FL/math.h>
33 #include <stdio.h>
34 #include "flstring.h"
35
Fl_Valuator(int X,int Y,int W,int H,const char * L)36 Fl_Valuator::Fl_Valuator(int X, int Y, int W, int H, const char* L)
37 : Fl_Widget(X,Y,W,H,L) {
38 align(FL_ALIGN_BOTTOM);
39 when(FL_WHEN_CHANGED);
40 value_ = 0;
41 previous_value_ = 1;
42 min = 0;
43 max = 1;
44 A = 0.0;
45 B = 1;
46 }
47
48 const double epsilon = 4.66e-10;
49
step(double s)50 void Fl_Valuator::step(double s) {
51 if (s < 0) s = -s;
52 A = rint(s);
53 B = 1;
54 while (fabs(s-A/B) > epsilon && B<=(0x7fffffff/10)) {B *= 10; A = rint(s*B);}
55 }
56
precision(int p)57 void Fl_Valuator::precision(int p) {
58 A = 1.0;
59 for (B = 1; p--;) B *= 10;
60 }
61
value_damage()62 void Fl_Valuator::value_damage() {damage(FL_DAMAGE_EXPOSE);} // by default do partial-redraw
63
value(double v)64 int Fl_Valuator::value(double v) {
65 clear_changed();
66 if (v == value_) return 0;
67 value_ = v;
68 value_damage();
69 return 1;
70 }
71
softclamp(double v)72 double Fl_Valuator::softclamp(double v) {
73 int which = (min<=max);
74 double p = previous_value_;
75 if ((v<min)==which && p!=min && (p<min)!=which) return min;
76 else if ((v>max)==which && p!=max && (p>max)!=which) return max;
77 else return v;
78 }
79
80 // inline void Fl_Valuator::handle_push() {previous_value_ = value_;}
81
handle_drag(double v)82 void Fl_Valuator::handle_drag(double v) {
83 if (v != value_) {
84 value_ = v;
85 value_damage();
86 set_changed();
87 if (when() & FL_WHEN_CHANGED) do_callback();
88 }
89 }
90
handle_release()91 void Fl_Valuator::handle_release() {
92 if (when()&FL_WHEN_RELEASE) {
93 // insure changed() is off even if no callback is done. It may have
94 // been turned on by the drag, and then the slider returned to it's
95 // initial position:
96 clear_changed();
97 // now do the callback only if slider in new position or always is on:
98 if (value_ != previous_value_ || when() & FL_WHEN_NOT_CHANGED) {
99 do_callback();
100 }
101 }
102 }
103
round(double v)104 double Fl_Valuator::round(double v) {
105 if (A) return rint(v*B/A)*A/B;
106 else return v;
107 }
108
clamp(double v)109 double Fl_Valuator::clamp(double v) {
110 if ((v<min)==(min<=max)) return min;
111 else if ((v>max)==(min<=max)) return max;
112 else return v;
113 }
114
increment(double v,int n)115 double Fl_Valuator::increment(double v, int n) {
116 if (!A) return v+n*(max-min)/100;
117 if (min > max) n = -n;
118 return (rint(v*B/A)+n)*A/B;
119 }
120
format(char * buffer)121 int Fl_Valuator::format(char* buffer) {
122 double v = value();
123 // MRS: THIS IS A HACK - RECOMMEND ADDING BUFFER SIZE ARGUMENT
124 if (!A || !B) return snprintf(buffer, 128, "%g", v);
125
126 // Figure out how many digits are required to correctly format the
127 // value.
128 int i, c = 0;
129 char temp[32];
130 // output a number with many digits after the decimal point. This
131 // seems to be needed to get high precission
132 snprintf(temp, sizeof(temp), "%.12f", A/B);
133 // strip all trailing 0's
134 for (i=strlen(temp)-1; i>0; i--) {
135 if (temp[i]!='0') break;
136 }
137 // count digits until we find the decimal point (or comma or whatever
138 // letter is set in the current locale)
139 for (; i>0; i--, c++) {
140 if (!isdigit(temp[i])) break;
141 }
142
143 // MRS: THIS IS A HACK - RECOMMEND ADDING BUFFER SIZE ARGUMENT
144 return snprintf(buffer, 128, "%.*f", c, v);
145 }
146
147 //
148 // End of "$Id: Fl_Valuator.cxx 5190 2006-06-09 16:16:34Z mike $".
149 //
150