Added basic rounding settings.

1 files changed, 71 insertions, 17 deletions

diff --git a/src/org/unitConverter/converterGUI/UnitConverterGUI.java b/src/org/unitConverter/converterGUI/UnitConverterGUI.java
index aa81a74..daae2c6 100644
--- a/src/org/unitConverter/converterGUI/UnitConverterGUI.java
+++ b/src/org/unitConverter/converterGUI/UnitConverterGUI.java
@@ -24,6 +24,7 @@ import java.awt.event.KeyEvent;
 import java.io.File;
 import java.math.BigDecimal;
 import java.math.MathContext;
+import java.math.RoundingMode;
 import java.text.DecimalFormat;
 import java.text.FieldPosition;
 import java.text.NumberFormat;
@@ -75,7 +76,18 @@ final class UnitConverterGUI {
 	 * A tab in the View.
 	 */
 	private enum Pane {
-		UNIT_CONVERTER, EXPRESSION_CONVERTER, UNIT_VIEWER, PREFIX_VIEWER;
+		UNIT_CONVERTER, EXPRESSION_CONVERTER, UNIT_VIEWER, PREFIX_VIEWER, SETTINGS;
+	}
+	
+	/**
+	 * Different types of rounding.
+	 * 
+	 * Significant digits: Rounds to a number of digits.  i.e. with precision 5, 12345.6789 rounds to 12346.
+	 * Decimal places: Rounds to a number of digits after the decimal point, i.e. with precision 5, 12345.6789 rounds to 12345.67890.
+	 * Scientific: Rounds based on the number of digits and operations, following standard scientific rounding.
+	 */
+	private static enum RoundingType {
+		SIGNIFICANT_DIGITS, DECIMAL_PLACES, SCIENTIFIC;
 	}
 
 	private static class Presenter {
@@ -125,7 +137,14 @@ final class UnitConverterGUI {
 
 		private final Comparator<String> prefixNameComparator;
 
-		private int significantFigures = 6;
+		/*
+		 * Rounding-related settings. I am using my own system, and not MathContext,
+		 * because MathContext does not support decimal place based or scientific
+		 * rounding, only significant digit based rounding.
+		 */
+		private int precision = 6;
+
+		private RoundingType roundingType = RoundingType.SIGNIFICANT_DIGITS;
 
 		/**
 		 * Creates the presenter.
@@ -213,10 +232,10 @@ final class UnitConverterGUI {
 			}
 			final double value = from.convertTo(to, beforeValue);
 
-			final String output = this.getRoundedString(value);
+			final String output = this.getRoundedString(new BigDecimal(value));
 
-			this.view.setDimensionConverterOutputText(
-					String.format("%s %s = %s %s", this.view.getDimensionConverterText(), fromSelection, output, toSelection));
+			this.view.setDimensionConverterOutputText(String.format("%s %s = %s %s",
+					this.view.getDimensionConverterText(), fromSelection, output, toSelection));
 		}
 
 		/**
@@ -271,7 +290,7 @@ final class UnitConverterGUI {
 				value = from.convertTo(to, 1);
 
 				// round value
-				final String output = this.getRoundedString(value);
+				final String output = this.getRoundedString(new BigDecimal(value));
 
 				this.view.setExpressionConverterOutputText(
 						String.format("%s = %s %s", fromUnitString, output, toUnitString));
@@ -280,7 +299,7 @@ final class UnitConverterGUI {
 				value = SI.ONE.dividedBy((LinearUnit) from).convertTo(to, 1);
 
 				// round value
-				final String output = this.getRoundedString(value);
+				final String output = this.getRoundedString(new BigDecimal(value));
 
 				this.view.setExpressionConverterOutputText(
 						String.format("1 / %s = %s %s", fromUnitString, output, toUnitString));
@@ -316,10 +335,23 @@ final class UnitConverterGUI {
 		 * @since 2019-04-14
 		 * @since v0.2.0
 		 */
-		private final String getRoundedString(final double value) {
-			// round value
-			final BigDecimal bigValue = new BigDecimal(value).round(new MathContext(this.significantFigures));
-			String output = bigValue.toString();
+		private final String getRoundedString(final BigDecimal value) {
+			// round value based on rounding type
+			final BigDecimal roundedValue;
+			switch (roundingType) {
+			case DECIMAL_PLACES:
+				roundedValue = value.setScale(precision, RoundingMode.HALF_EVEN);
+				break;
+			case SCIENTIFIC:
+				throw new UnsupportedOperationException("Not yet implemented.");
+			case SIGNIFICANT_DIGITS:
+				roundedValue = value.round(new MathContext(this.precision));
+				break;
+			default:
+				throw new AssertionError("Invalid switch condition.");
+			}
+			
+			String output = roundedValue.toString();
 
 			// remove trailing zeroes
 			if (output.contains(".")) {
@@ -364,12 +396,12 @@ final class UnitConverterGUI {
 		}
 
 		/**
-		 * @param significantFigures new value of significantFigures
+		 * @param precision new value of precision
 		 * @since 2019-01-15
 		 * @since v0.1.0
 		 */
-		public final void setSignificantFigures(final int significantFigures) {
-			this.significantFigures = significantFigures;
+		public final void setPrecision(final int precision) {
+			this.precision = precision;
 		}
 
 		/**
@@ -416,6 +448,14 @@ final class UnitConverterGUI {
 		public final Set<String> unitNameSet() {
 			return this.database.unitMapPrefixless().keySet();
 		}
+
+		/**
+		 * @param roundingType the roundingType to set
+		 * @since 2020-07-16
+		 */
+		public final void setRoundingType(RoundingType roundingType) {
+			this.roundingType = roundingType;
+		}
 	}
 
 	private static class View {
@@ -502,6 +542,8 @@ final class UnitConverterGUI {
 				return Pane.UNIT_VIEWER;
 			case 3:
 				return Pane.PREFIX_VIEWER;
+			case 4:
+				return Pane.SETTINGS;
 			default:
 				throw new AssertionError("No selected pane, or invalid pane.");
 			}
@@ -824,14 +866,18 @@ final class UnitConverterGUI {
 						
 						final JRadioButton fixedPrecision = new JRadioButton("Fixed Precision");
 						fixedPrecision.setSelected(true);
+						fixedPrecision.addActionListener(e -> this.presenter.setRoundingType(RoundingType.SIGNIFICANT_DIGITS));
 						roundingRuleButtons.add(fixedPrecision);
 						roundingPanel.add(fixedPrecision, new GridBagBuilder(0, 1).setAnchor(GridBagConstraints.LINE_START).build());
 						
 						final JRadioButton fixedDecimals = new JRadioButton("Fixed Decimal Places");
+						fixedDecimals.addActionListener(e -> this.presenter.setRoundingType(RoundingType.DECIMAL_PLACES));
 						roundingRuleButtons.add(fixedDecimals);
 						roundingPanel.add(fixedDecimals, new GridBagBuilder(0, 2).setAnchor(GridBagConstraints.LINE_START).build());
 						
 						final JRadioButton relativePrecision = new JRadioButton("Scientific Precision");
+						relativePrecision.setEnabled(false);
+						relativePrecision.addActionListener(e -> this.presenter.setRoundingType(RoundingType.SCIENTIFIC));
 						roundingRuleButtons.add(relativePrecision);
 						roundingPanel.add(relativePrecision, new GridBagBuilder(0, 3).setAnchor(GridBagConstraints.LINE_START).build());
 						
@@ -848,7 +894,7 @@ final class UnitConverterGUI {
 						sigDigSlider.setPaintLabels(true);
 
 						sigDigSlider.addChangeListener(
-								e -> this.presenter.setSignificantFigures(sigDigSlider.getValue()));
+								e -> this.presenter.setPrecision(sigDigSlider.getValue()));
 					}
 					
 					{ // prefix repetition settings
@@ -861,15 +907,18 @@ final class UnitConverterGUI {
 						final ButtonGroup prefixRuleButtons = new ButtonGroup();
 						
 						final JRadioButton noRepetition = new JRadioButton("No Repetition");
-						noRepetition.setSelected(true);
+						noRepetition.setEnabled(false);
 						prefixRuleButtons.add(noRepetition);
 						prefixRepetitionPanel.add(noRepetition, new GridBagBuilder(0, 0).setAnchor(GridBagConstraints.LINE_START).build());
 						
 						final JRadioButton noRestriction = new JRadioButton("No Restriction");
+						noRestriction.setSelected(true);
+						noRestriction.setEnabled(false);
 						prefixRuleButtons.add(noRestriction);
 						prefixRepetitionPanel.add(noRestriction, new GridBagBuilder(0, 1).setAnchor(GridBagConstraints.LINE_START).build());
 						
 						final JRadioButton customRepetition = new JRadioButton("Custom Repetition Rule");
+						customRepetition.setEnabled(false);
 						prefixRuleButtons.add(customRepetition);
 						prefixRepetitionPanel.add(customRepetition, new GridBagBuilder(0, 2).setAnchor(GridBagConstraints.LINE_START).build());
 					}
@@ -884,19 +933,22 @@ final class UnitConverterGUI {
 						final ButtonGroup searchRuleButtons = new ButtonGroup();
 						
 						final JRadioButton noPrefixes = new JRadioButton("Never Include Prefixed Units");
-						noPrefixes.setSelected(true);
+						noPrefixes.setEnabled(false);
 						searchRuleButtons.add(noPrefixes);
 						searchingPanel.add(noPrefixes, new GridBagBuilder(0, 0).setAnchor(GridBagConstraints.LINE_START).build());
 						
 						final JRadioButton fixedPrefixes = new JRadioButton("Include Some Prefixes");
+						fixedPrefixes.setEnabled(false);
 						searchRuleButtons.add(fixedPrefixes);
 						searchingPanel.add(fixedPrefixes, new GridBagBuilder(0, 1).setAnchor(GridBagConstraints.LINE_START).build());
 						
 						final JRadioButton explicitPrefixes = new JRadioButton("Include Explicit Prefixes");
+						explicitPrefixes.setEnabled(false);
 						searchRuleButtons.add(explicitPrefixes);
 						searchingPanel.add(explicitPrefixes, new GridBagBuilder(0, 2).setAnchor(GridBagConstraints.LINE_START).build());
 						
 						final JRadioButton alwaysInclude = new JRadioButton("Include All Single Prefixes");
+						alwaysInclude.setEnabled(false);
 						searchRuleButtons.add(alwaysInclude);
 						searchingPanel.add(alwaysInclude, new GridBagBuilder(0, 3).setAnchor(GridBagConstraints.LINE_START).build());
 					}
@@ -909,9 +961,11 @@ final class UnitConverterGUI {
 						
 						final JCheckBox showAllVariations = new JCheckBox("Show Symbols in \"Convert Units\"");
 						showAllVariations.setSelected(true);
+						showAllVariations.setEnabled(false);
 						miscPanel.add(showAllVariations, new GridBagBuilder(0, 0).setAnchor(GridBagConstraints.LINE_START).build());
 						
 						final JButton unitFileButton = new JButton("Manage Unit Data Files");
+						unitFileButton.setEnabled(false);
 						miscPanel.add(unitFileButton, new GridBagBuilder(0, 1).setAnchor(GridBagConstraints.LINE_START).build());
 					}
 				}