|
1
4 package gnu.math;
5 import java.text.FieldPosition  ;
6
7
11
14
15 public class FixedRealFormat extends java.text.Format
16 {
17 private int i, d;
18 public int getMaximumFractionDigits() { return d; }
19 public int getMinimumIntegerDigits() { return i; }
20 public void setMaximumFractionDigits(int d) { this.d = d; }
21 public void setMinimumIntegerDigits(int i) { this.i = i; }
22
23 public int width;
25 public int scale;
26 public char padChar;
27 public boolean showPlus;
28 public boolean internalPad;
29 public char overflowChar;
30
31 public void format(RatNum number, boolean negative,
32 StringBuffer sbuf, FieldPosition fpos)
33 {
34 int decimals = getMaximumFractionDigits();
35 int digits;
36 int oldSize = sbuf.length();
37 int signLen = 1;
38 if (negative)
39 sbuf.append('-');
40 else if (showPlus)
41 sbuf.append('+');
42 else
43 signLen = 0;
44 String string;
45 int length;
46 if (decimals < 0)
47 {
48 double val = number.doubleValue();
49 int log = (int) (Math.log(val) / ExponentialFormat.LOG10);
50 int cur_scale = log == 0x80000000 ? 0 : 17 - log;
51 string = RealNum.toScaledInt(val, cur_scale).toString();
52 int i = string.length();
53 digits = i - cur_scale + scale;
54 if (width > 0)
55 decimals = width - signLen - 1 - digits;
56 else
57 decimals = (i > 16 ? 16 : i) - digits;
58 if (decimals < 0)
59 decimals = 0;
60 sbuf.append(string);
61 int digStart = oldSize + signLen;
62 int digEnd = digStart + digits + decimals;
63 i = sbuf.length();
64 char nextDigit;
65 if (digEnd >= i)
66 {
67 digEnd = i;
68 nextDigit = '0';
69 }
70 else
71 nextDigit = sbuf.charAt(digEnd);
72 boolean addOne = nextDigit >= '5';
73 char skip = addOne ? '9' : '0';
74 while (digEnd > digStart + digits && sbuf.charAt(digEnd - 1) == skip)
75 digEnd--;
76 length = digEnd - digStart;
77 decimals = length - digits;
78 if (addOne)
79 {
80 if (ExponentialFormat.addOne(sbuf, digStart, digEnd))
81 {
82 digits++;
83 decimals = 0;
84 length = digits;
85 }
86 }
87 if (decimals == 0 && (width <= 0
88 || signLen + digits + 1 < width))
89 {
90 decimals = 1;
91 length++;
92 sbuf.insert(digStart+digits, '0');
94 }
95 sbuf.setLength(digStart + length);
96 }
97 else
98 {
99 string = RealNum.toScaledInt(number, decimals+scale).toString();
100 sbuf.append(string);
101 length = string.length();
102 digits = length - decimals;
103 }
104
105 int total_digits = digits + decimals;
106 int zero_digits = getMinimumIntegerDigits();
108 if (digits >= 0 && digits > zero_digits)
109 zero_digits = 0;
110 else
111 zero_digits -= digits;
112 if (digits + zero_digits <= 0
114 && (width <= 0 || width > decimals + 1 + signLen))
115 zero_digits++;
116 int needed = signLen + length + zero_digits + 1;
117 int padding = width - needed;
118 for (int i = zero_digits; --i >= 0; )
119 sbuf.insert(oldSize + signLen, '0');
120 if (padding >= 0)
121 {
122 int i = oldSize;
123 if (internalPad && signLen > 0)
124 i++;
125 while (--padding >= 0)
126 sbuf.insert(i, padChar);
127 }
128 else if (overflowChar != '\0')
129 {
130 sbuf.setLength(oldSize);
131 for (i = width; --i >= 0; )
132 sbuf.append(overflowChar);
133 return;
134 }
135 int newSize = sbuf.length();
136 sbuf.insert(newSize - decimals, '.');
137
153 }
154
155 public void format(RatNum number, StringBuffer sbuf, FieldPosition fpos)
156 {
157 boolean negative = number.isNegative();
158 if (negative)
159 number = (RatNum) number.rneg();
160 format(number, negative, sbuf, fpos);
161 }
162
163 public void format(RealNum number, StringBuffer sbuf, FieldPosition fpos)
164 {
165 if (number instanceof RatNum)
166 format((RatNum) number, sbuf, fpos);
167 else
168 format(number.doubleValue(), sbuf, fpos);
169 }
170
171 public StringBuffer format(long num, StringBuffer sbuf, FieldPosition fpos)
172 {
173 format(IntNum.make(num), sbuf, fpos);
174 return sbuf;
175 }
176
177 public StringBuffer format(double num, StringBuffer sbuf, FieldPosition fpos)
178 {
179 boolean negative;
180 if (num < 0)
181 {
182 negative = true;
183 num = -num;
184 }
185 else
186 negative = false;
187 format(DFloNum.toExact(num), negative, sbuf, fpos);
188 return sbuf;
189 }
190
191 public StringBuffer format(Object num, StringBuffer sbuf, FieldPosition fpos)
192 {
193 return format(((RealNum) num).doubleValue(), sbuf, fpos);
195 }
196
197 public java.lang.Number parse(String text, java.text.ParsePosition status)
198 {
199 throw new Error ("RealFixedFormat.parse - not implemented");
200 }
201 public Object parseObject(String text, java.text.ParsePosition status)
202 {
203 throw new Error ("RealFixedFormat.parseObject - not implemented");
204 }
205
206 }
207 |
Popular Tags |
Java API By Example, From Geeks To Geeks.