X-Git-Url: https://gerrit.simantics.org/r/gitweb?p=simantics%2Fplatform.git;a=blobdiff_plain;f=bundles%2Forg.simantics.utils%2Fsrc%2Forg%2Fsimantics%2Futils%2Fformat%2FFormattingUtils.java;fp=bundles%2Forg.simantics.utils%2Fsrc%2Forg%2Fsimantics%2Futils%2Fformat%2FFormattingUtils.java;h=747da6b511c8af0ed17f89a158eeb62bab153e15;hp=0000000000000000000000000000000000000000;hb=969bd23cab98a79ca9101af33334000879fb60c5;hpb=866dba5cd5a3929bbeae85991796acb212338a08

diff --git a/bundles/org.simantics.utils/src/org/simantics/utils/format/FormattingUtils.java b/bundles/org.simantics.utils/src/org/simantics/utils/format/FormattingUtils.java
new file mode 100644
index 000000000..747da6b51
--- /dev/null
+++ b/bundles/org.simantics.utils/src/org/simantics/utils/format/FormattingUtils.java
@@ -0,0 +1,99 @@
+/*******************************************************************************
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management
+ * in Industry THTH ry.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     VTT Technical Research Centre of Finland - initial API and implementation
+ *******************************************************************************/
+package org.simantics.utils.format;
+
+import java.math.BigDecimal;
+import java.math.MathContext;
+import java.text.DecimalFormat;
+import java.text.DecimalFormatSymbols;
+import java.text.FieldPosition;
+import java.text.Format;
+import java.text.NumberFormat;
+import java.text.ParsePosition;
+import java.util.Locale;
+
+/**
+ * @author Antti Villberg
+ */
+public class FormattingUtils {
+
+    public static final FormattingUtil US      = new FormattingUtil(5, 5, Locale.US);
+    public static final FormattingUtil DEFAULT = US;
+
+    public static String engineeringFormat(Object value) {
+        return DEFAULT.engineeringFormat(value);
+    }
+
+    public static Format significantDigitFormat(int withSignificantDigits) {
+        return significantDigitFormat(withSignificantDigits, false);
+    }
+
+    public static Format significantDigitFormat(int withSignificantDigits, boolean stripTrailingZeros) {
+        if (withSignificantDigits < 1)
+            throw new IllegalArgumentException("withSignificantDigits must be > 0, got " + withSignificantDigits);
+        StringBuilder sb = new StringBuilder(withSignificantDigits + 3);
+        sb.append("0.");
+        for (int i = 0; i < withSignificantDigits-1; i++)
+            sb.append("#");
+        sb.append("E0");
+        NumberFormat low = new DecimalFormat(sb.toString());
+        low.setGroupingUsed(false);
+        NumberFormat hi = new SignificantDigitFormat(withSignificantDigits, stripTrailingZeros);
+        Format format = new SwitchFormat(0.1, 1, low, hi, hi);
+        return format;
+    }
+
+    private static class SignificantDigitFormat extends NumberFormat {
+
+        private static final long serialVersionUID = 1079268918077141671L;
+
+        private MathContext mc;
+        private boolean stripTrailingZeros;
+        private boolean fixDecimalSeparator;
+        private char decimalSeparator;
+
+        public SignificantDigitFormat(int digits, boolean stripTrailingZeros) {
+            this.mc = new MathContext(digits);
+            this.stripTrailingZeros = stripTrailingZeros;
+            DecimalFormatSymbols symbols = DecimalFormatSymbols.getInstance();
+            decimalSeparator = symbols.getDecimalSeparator();
+            // BigDecimal always formats doubles with '.' as decimal separator.
+            if (decimalSeparator != '.')
+                fixDecimalSeparator = true;
+            else
+                fixDecimalSeparator = false;
+        }
+
+        @Override
+        public StringBuffer format(double number, StringBuffer toAppendTo, FieldPosition pos) {
+            BigDecimal big = new BigDecimal(number, mc);
+            if (stripTrailingZeros)
+                big = big.stripTrailingZeros();
+            String str = big.toString();
+            if (fixDecimalSeparator)
+                str = str.replace('.', decimalSeparator);
+            return toAppendTo.append(str);
+        }
+
+        @Override
+        public StringBuffer format(long number, StringBuffer toAppendTo, FieldPosition pos) {
+            return toAppendTo.append(number);
+        }
+
+        @Override
+        public Number parse(String source, ParsePosition parsePosition) {
+            return 0;
+        }
+
+    }
+
+}