refactor + russian language support

res/layout-land/main.xml

@@ -100,10 +100,10 @@
 														   style="@style/control_button_style"
 														   a:onClick="numericButtonClickHandler"/>
 
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/pasteButton"
+			<ImageButton a:id="@+id/pasteButton"
-														   a:text="@string/c_paste"
+						 a:src="@drawable/paste"
-														   style="@style/control_button_style"
+						 style="@style/control_button_style"
-														   a:onClick="pasteButtonClickHandler"/>
+						 a:onClick="pasteButtonClickHandler"/>
 
 		</LinearLayout>
 
@@ -185,7 +185,8 @@
 
 			<org.solovyev.android.view.widgets.DirectionDragButton
 					a:id="@+id/varsButton"
-					a:text="@string/c_vars"
+					a:text="π,e,…"
+					a:textStyle="italic"
 					a:onClick="varsButtonClickHandler"
 					style="@style/control_button_style"/>
 

res/layout-port/main.xml

@@ -130,10 +130,10 @@
 																   style="@style/digit_button_style"
 																   a:onClick="digitButtonClickHandler"/>
 
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/pasteButton"
+			<ImageButton a:id="@+id/pasteButton"
-																   a:text="@string/c_paste"
+						 a:src="@drawable/paste"
-																   style="@style/control_button_style"
+						 style="@style/control_button_style"
-																   a:onClick="pasteButtonClickHandler"/>
+						 a:onClick="pasteButtonClickHandler"/>
 
 
 		</LinearLayout>
@@ -198,7 +198,8 @@
 
 			<org.solovyev.android.view.widgets.DirectionDragButton
 					a:id="@+id/varsButton"
-					a:text="@string/c_vars"
+					a:text="π,e,…"
+					a:textStyle="italic"
 					a:onClick="varsButtonClickHandler"
 					style="@style/control_button_style"/>
 

res/values-ru/strings.xml

@@ -1,4 +1,58 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
     <string name="c_app_name">Калькулятор</string>
+    <string name="c_app_settings">Калькулятор</string>
+    <string name="c_syntax_error">Ошибка</string>
+    <string name="c_result_copied">Результат скопирован в буфер!</string>
+	<string name="c_settings">Настройки</string>
+	<string name="c_help">Помощь</string>
+	<string name="c_about">О программе</string>
+	<string name="c_vars_and_constants">Переменные и константы</string>
+
+	<!--PREFERENCE ACTIVITY-->
+	<string name="c_prefs_main_category">Основные настройки</string>
+	<string name="c_prefs_drag_button_category">Настройки кнопок</string>
+
+
+	<string name="c_down">Вниз</string>
+	<string name="c_up">Вверх</string>
+	<string name="c_restart">Перезапуск</string>
+
+	<!--ABOUT ACTIVITY-->
+	<string name="c_copyright">Copyright (c) 2009-2011.\nПрограмма создана serso aka se.solovyev.\n
+		За подробной информацией, пожалуйста,\nобращайтесь на почту\n<a href="mailto:se.solovyev@gmail.com">se.solovyev@gmail.com</a>
+		\nили посетите\n<a href="http://se.solovyev.org">http://se.solovyev.org</a>
+	</string>
+
+	<string name="c_undo">назад</string>
+	<string name="c_redo">вперёд</string>
+	<string name="c_paste">вставить</string>
+	<string name="c_vars">переменные</string>
+
+	<string name="c_calc_color_display_title">Подсветка выражений</string>
+	<string name="p_calc_result_precision_title">Точность результата</string>
+	<string name="c_exit">Выход</string>
+	<string name="c_add">Добавить</string>
+	<string name="c_cancel">Отмена</string>
+	<string name="c_save">Сохранить</string>
+	<string name="c_remove">Удалить</string>
+	<string name="c_yes">Да</string>
+	<string name="c_no">Нет</string>
+	<string name="c_var_removal_confirmation">Подтверждение удаления</string>
+	<string name="c_var_removal_confirmation_question">Вы действительно хотите удалить переменную \'%s\'?</string>
+	<string name="c_var_name">Имя</string>
+	<string name="c_var_value">Значение</string>
+	<string name="c_var_description">Описание</string>
+	<string name="c_var_create_var">Создать переменную</string>
+	<string name="c_var_edit_var">Редактировать переменную</string>
+
+	<string name="c_value.is.not.a.number">Значение - не число!</string>
+	<string name="c_var.name.clashes">Имя переменной не может быть зарезервированным системным именем!</string>
+	<string name="c_var.already.exists">Переменная с таким именем уже существует!</string>
+	<string name="c_name.is.empty">Имя не может быть пустым!</string>
+	<string name="c_sys.var.cannot.be.changed">Системная переменная не может быть изменена!</string>
+
+	<string name="c_pi_description">Отношение длины окружности к диаметру</string>
+	<string name="c_e_description">Вещесвтенное число, такое что производная функции f(x) = e^x в точке x = 0 равно 1</string>
+	<string name="c_i_description">Мнимая единица, определённая как i^2 = −1</string>
 </resources>

res/values/strings.xml

@@ -27,7 +27,7 @@
 
 	<string name="c_undo">undo</string>
 	<string name="c_redo">redo</string>
-	<string name="c_clear">clear</string>
+	<string name="c_clear">clr</string>
 	<string name="c_paste">paste</string>
 	<string name="c_vars">vars</string>
 
@@ -47,4 +47,14 @@
 	<string name="c_var_description">Description</string>
 	<string name="c_var_create_var">Create variable</string>
 	<string name="c_var_edit_var">Edit variable</string>
+
+	<string name="c_value.is.not.a.number">Value is not a number!</string>
+	<string name="c_var.name.clashes">Variable name clashes with function name!</string>
+	<string name="c_var.already.exists">Variable with same name already exists!</string>
+	<string name="c_name.is.empty">Name is empty!</string>
+	<string name="c_sys.var.cannot.be.changed">System variable cannot be changed!</string>
+
+	<string name="c_pi_description">Ratio of any circle\'s circumference to its diameter</string>
+	<string name="c_e_description">Unique real number such that the value of the derivative (slope of the tangent line) of the function f(x) = e^x at the point x = 0 is equal to 1</string>
+	<string name="c_i_description">Imaginary unit, defined such that i^2 = −1</string>
 </resources>

res/xml/main_preferences.xml

@@ -2,7 +2,7 @@
 
 <PreferenceScreen xmlns:a="http://schemas.android.com/apk/res/android"
 				  xmlns:range="http://schemas.android.com/apk/res/org.solovyev.android.calculator">
-	<PreferenceCategory a:title="@string/c_prefs_drag_button_category">
+	<PreferenceCategory a:title="@string/c_prefs_main_category">
 
 		<org.solovyev.android.view.prefs.NumberPickerDialogPreference
 				a:key="@string/p_calc_result_precision_key"

src/main/java/org/solovyev/android/calculator/CalculatorActivity.java

@@ -18,6 +18,7 @@ import android.widget.TextView;
 import bsh.EvalError;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
+import org.solovyev.android.calculator.model.CalculatorModel;
 import org.solovyev.android.view.FontSizeAdjuster;
 import org.solovyev.android.view.widgets.*;
 import org.solovyev.common.BooleanMapper;
@@ -41,9 +42,6 @@ public class CalculatorActivity extends Activity implements FontSizeAdjuster, Sh
 	@NotNull
 	private CalculatorView calculatorView;
 
-	@NotNull
-	private CalculatorModel calculatorModel;
-
 	@NotNull
 	private BroadcastReceiver insertTextReceiver;
 
@@ -125,16 +123,13 @@ public class CalculatorActivity extends Activity implements FontSizeAdjuster, Sh
 	private synchronized void firstTimeInit() {
 		if (!initialized) {
 			try {
-				if (!CalculatorModel.isLoaded()) {
+				CalculatorModel.instance.init(this);
-					CalculatorModel.init(this);
-				}
-				this.calculatorModel = CalculatorModel.getInstance();
 			} catch (EvalError evalError) {
 				// todo serso: create serso runtime exception
 				throw new RuntimeException("Could not initialize interpreter!");
 			}
 
-			this.calculatorView = new CalculatorView(this, this.calculatorModel);
+			this.calculatorView = new CalculatorView(this, CalculatorModel.instance);
 
 			initialized = true;
 		}
@@ -279,7 +274,7 @@ public class CalculatorActivity extends Activity implements FontSizeAdjuster, Sh
 	public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, @Nullable String s) {
 		dpclRegister.announce().onDragPreferencesChange(SimpleOnDragListener.getPreferences(CalculatorActivity.this));
 
-		this.calculatorModel.load(this);
+		CalculatorModel.instance.reset(this);
 
 		final Boolean colorExpressionsInBracketsDefault = new BooleanMapper().parseValue(this.getString(R.string.p_calc_color_display));
 		assert colorExpressionsInBracketsDefault != null;

src/main/java/org/solovyev/android/calculator/CalculatorEditor.java

@@ -12,7 +12,7 @@ import android.util.AttributeSet;
 import android.util.Log;
 import android.widget.EditText;
 import org.jetbrains.annotations.NotNull;
-import org.solovyev.android.calculator.math.MathEntityType;
+import org.solovyev.android.calculator.math.MathType;
 
 /**
  * User: serso
@@ -62,9 +62,9 @@ public class CalculatorEditor extends EditText {
 		final StringBuilder text1 = new StringBuilder();
 
 		for (int i = 0; i < text.length(); i++) {
-			final MathEntityType.Result mathType = MathEntityType.getType(text, i);
+			final MathType.Result mathType = MathType.getType(text, i);
 
-			switch (mathType.getMathEntityType()) {
+			switch (mathType.getMathType()) {
 				case open_group_symbol:
 					numberOfOpenGroupSymbols++;
 					maxNumberOfOpenGroupSymbols = Math.max(maxNumberOfOpenGroupSymbols, numberOfOpenGroupSymbols);
@@ -75,10 +75,10 @@ public class CalculatorEditor extends EditText {
 					text1.append(text.charAt(i));
 					break;
 				case function:
-					i = processHighlightedText(text1, i, mathType.getS(), "i");
+					i = processHighlightedText(text1, i, mathType.getMatch(), "i");
 					break;
 				case constant:
-					i = processHighlightedText(text1, i, mathType.getS(), "b");
+					i = processHighlightedText(text1, i, mathType.getMatch(), "b");
 					break;
 				default:
 					text1.append(text.charAt(i));
@@ -113,15 +113,15 @@ public class CalculatorEditor extends EditText {
 		for (; i < s.length(); i++) {
 			char ch = s.charAt(i);
 
-			if (MathEntityType.openGroupSymbols.contains(ch)) {
+			if (MathType.openGroupSymbols.contains(ch)) {
 				result.append(ch);
 				result.append("</font>");
 				i = processBracketGroup(result, s, i + 1, numberOfOpenings + 1, maxNumberOfGroups);
 				result.append("<font color=\"").append(getColor(maxNumberOfGroups, numberOfOpenings)).append("\">");
-				if (i < s.length() && MathEntityType.closeGroupSymbols.contains(s.charAt(i))) {
+				if (i < s.length() && MathType.closeGroupSymbols.contains(s.charAt(i))) {
 					result.append(s.charAt(i));
 				}
-			} else if (MathEntityType.closeGroupSymbols.contains(ch)) {
+			} else if (MathType.closeGroupSymbols.contains(ch)) {
 				break;
 			} else {
 				result.append(ch);

src/main/java/org/solovyev/android/calculator/CalculatorModel.java

@@ -1,212 +0,0 @@
-/*
- * Copyright (c) 2009-2011. Created by serso aka se.solovyev.
- * For more information, please, contact se.solovyev@gmail.com
- */
-
-package org.solovyev.android.calculator;
-
-import android.content.Context;
-import android.content.SharedPreferences;
-import android.preference.PreferenceManager;
-import bsh.EvalError;
-import bsh.Interpreter;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-import org.solovyev.common.NumberMapper;
-import org.solovyev.common.exceptions.SersoException;
-import org.solovyev.common.utils.MathUtils;
-import org.solovyev.util.math.Complex;
-
-/**
- * User: serso
- * Date: 9/12/11
- * Time: 11:38 PM
- */
-
-public class CalculatorModel {
-
-	@NotNull
-	private Interpreter interpreter;
-
-	@NotNull
-	private final Object interpreterMonitor = new Object();
-
-	private int numberOfFractionDigits = 5;
-
-	@NotNull
-	public final Preprocessor preprocessor = new ToJsclPreprocessor();
-
-	@NotNull
-	private final VarsRegister varsRegister = new VarsRegister();
-
-	private static CalculatorModel instance;
-
-	public CalculatorModel(@Nullable Context context) {
-		load(context);
-
-		reset();
-	}
-
-	public void reset() {
-		synchronized (interpreterMonitor) {
-			try {
-				interpreter = new Interpreter();
-				interpreter.eval(ToJsclPreprocessor.wrap(JsclOperation.importCommands, "/jscl/editorengine/commands"));
-
-				/*for (Var var : varsRegister.getVars()) {
-					if (!var.isSystem()) {
-						exec(var.getName() + "=" + var.getValue() + ";");
-					}
-				}*/
-			} catch (EvalError evalError) {
-				throw new RuntimeException(evalError);
-			}
-		}
-	}
-
-	public String evaluate(@NotNull JsclOperation operation, @NotNull String expression) throws EvalError, ParseException {
-
-		final StringBuilder sb = new StringBuilder();
-
-		sb.append(preprocessor.process(expression));
-
-		//Log.d(CalculatorModel.class.getName(), "Preprocessed expression: " + preprocessedExpression);
-
-		final Object evaluationObject;
-		synchronized (interpreterMonitor) {
-			evaluationObject = interpreter.eval(ToJsclPreprocessor.wrap(operation, sb.toString()));
-		}
-		String result = String.valueOf(evaluationObject).trim();
-
-		try {
-			result = String.valueOf(round(result));
-		} catch (NumberFormatException e) {
-			if (result.contains("sqrt(-1)")) {
-				try {
-					result = createResultForComplexNumber(result.replace("sqrt(-1)", "i"));
-				} catch (NumberFormatException e1) {
-					// throw original one
-					throw new ParseException(e);
-				}
-
-			} else {
-				throw new ParseException(e);
-			}
-		}
-
-		return result;
-	}
-
-	public String createResultForComplexNumber(@NotNull final String s) {
-		final Complex complex = new Complex();
-
-		String result = "";
-		// may be it's just complex number
-		int plusIndex = s.lastIndexOf("+");
-		if (plusIndex >= 0) {
-			complex.setReal(round(s.substring(0, plusIndex)));
-			result += complex.getReal();
-			result += "+";
-		} else {
-			plusIndex = s.lastIndexOf("-");
-			if (plusIndex >= 0) {
-				complex.setReal(round(s.substring(0, plusIndex)));
-				result += complex.getReal();
-				result += "-";
-			}
-		}
-
-
-		int multiplyIndex = s.indexOf("*");
-		if (multiplyIndex >= 0) {
-			complex.setImaginary(round(s.substring(plusIndex >= 0 ? plusIndex + 1 : 0, multiplyIndex)));
-			result += complex.getImaginary();
-
-		}
-
-		result += "i";
-
-		return result;
-	}
-
-	private Double round(@NotNull String result) {
-		final Double dResult = Double.valueOf(result);
-		return MathUtils.round(dResult, numberOfFractionDigits);
-	}
-
-	public synchronized void load(@Nullable Context context) {
-		if (context != null) {
-			final SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
-
-			final NumberMapper<Integer> integerNumberMapper = new NumberMapper<Integer>(Integer.class);
-			this.setNumberOfFractionDigits(integerNumberMapper.parseValue(preferences.getString(context.getString(R.string.p_calc_result_precision_key), context.getString(R.string.p_calc_result_precision))));
-		}
-
-		varsRegister.load(context);
-	}
-
-	public static class ParseException extends SersoException {
-		public ParseException(Throwable cause) {
-			super(cause);
-		}
-	}
-
-	public int getNumberOfFractionDigits() {
-		return numberOfFractionDigits;
-	}
-
-	public void setNumberOfFractionDigits(int numberOfFractionDigits) {
-		this.numberOfFractionDigits = numberOfFractionDigits;
-	}
-
-	public static synchronized void init(@Nullable Context context) throws EvalError {
-		if (!isLoaded()) {
-			instance = new CalculatorModel(context);
-		} else {
-			throw new RuntimeException("Calculator model already instantiated!");
-		}
-	}
-
-	public static CalculatorModel getInstance() {
-		if (!isLoaded()) {
-			throw new RuntimeException("CalculatorModel must be instantiated!");
-		}
-
-		return instance;
-	}
-
-	public static boolean isLoaded() {
-		return instance != null;
-	}
-
-
-	private void exec(String str) throws EvalError {
-		interpreter.eval(str);
-	}
-
-	private String eval(String str) throws EvalError {
-		return interpreter.eval(commands(str)).toString();
-	}
-
-
-	@NotNull
-	public VarsRegister getVarsRegister() {
-		return varsRegister;
-	}
-
-	String commands(String str) {
-		return commands(str, false);
-	}
-
-	String commands(String str, boolean found) {
-		for (int i = 0; i < cmds.length; i++) {
-			int n = str.length() - cmds[i].length() - 1;
-			if (n >= 0 && (" " + cmds[i].toLowerCase()).equals(str.substring(n)))
-				return commands(str.substring(0, n), true) + "." + cmds[i] + "()";
-		}
-		str = str.replaceAll("\n", "");
-		return found ? "jscl.math.Expression.valueOf(\"" + str + "\")" : str;
-	}
-
-	static final String cmds[] = new String[]{"expand", "factorize", "elementary", "simplify", "numeric", "toMathML", "toJava"};
-}

src/main/java/org/solovyev/android/calculator/CalculatorVarsActivity.java

@@ -16,7 +16,10 @@ import android.view.*;
 import android.widget.*;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
-import org.solovyev.android.calculator.math.MathEntityType;
+import org.solovyev.android.calculator.math.MathType;
+import org.solovyev.android.calculator.model.CalculatorModel;
+import org.solovyev.android.calculator.model.Var;
+import org.solovyev.android.calculator.model.VarsRegister;
 import org.solovyev.common.utils.StringUtils;
 
 import java.util.ArrayList;
@@ -36,7 +39,7 @@ public class CalculatorVarsActivity extends ListActivity {
 	protected void onCreate(Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
 
-		adapter = new VarsArrayAdapter(this, R.layout.var, R.id.var_text, new ArrayList<Var>(CalculatorModel.getInstance().getVarsRegister().getVars()));
+		adapter = new VarsArrayAdapter(this, R.layout.var, R.id.var_text, new ArrayList<Var>(CalculatorModel.instance.getVarsRegister().getVars()));
 		setListAdapter(adapter);
 
 		final ListView lv = getListView();
@@ -111,7 +114,7 @@ public class CalculatorVarsActivity extends ListActivity {
 
 			builder.create().show();
 		} else {
-			Toast.makeText(this, "System variable cannot be changed!", Toast.LENGTH_LONG).show();
+			Toast.makeText(this, getString(R.string.c_sys_var_cannot_be_changed), Toast.LENGTH_LONG).show();
 		}
 	}
 
@@ -135,7 +138,7 @@ public class CalculatorVarsActivity extends ListActivity {
 		@Override
 		public void onClick(DialogInterface dialog, int which) {
 			if (which == DialogInterface.BUTTON_POSITIVE) {
-				final String error;
+				final Integer error;
 
 				final EditText editName = (EditText) editView.findViewById(R.id.var_edit_name);
 				String name = editName.getText().toString();
@@ -147,13 +150,13 @@ public class CalculatorVarsActivity extends ListActivity {
 				String description = editDescription.getText().toString();
 
 
-				final VarsRegister varsRegister = CalculatorModel.getInstance().getVarsRegister();
+				final VarsRegister varsRegister = CalculatorModel.instance.getVarsRegister();
 				if (!StringUtils.isEmpty(name)) {
 					final Var varFromRegister = varsRegister.getVar(name);
 					if (varFromRegister == null || varFromRegister == editedInstance) {
-						final MathEntityType.Result mathType = MathEntityType.getType(name, 0);
+						final MathType.Result mathType = MathType.getType(name, 0);
 
-						if (mathType.getMathEntityType() == MathEntityType.text || mathType.getMathEntityType() == MathEntityType.constant) {
+						if (mathType.getMathType() == MathType.text || mathType.getMathType() == MathType.constant) {
 							boolean correctDouble = true;
 							try {
 								Double.valueOf(value);
@@ -167,20 +170,20 @@ public class CalculatorVarsActivity extends ListActivity {
 								varBuilder.setDescription(description);
 								error = null;
 							} else {
-								error = "Value is not a number!";
+								error = R.string.c_value_is_not_a_number;
 							}
 						} else {
-							error = "Variable name clashes with function name!";
+							error = R.string.c_var_name_clashes;
 						}
 					} else {
-						error = "Variable with same name already exist!";
+						error = R.string.c_var_already_exists;
 					}
 				} else {
-					error = "Name is empty!";
+					error = R.string.c_name_is_empty;
 				}
 
 				if (error != null) {
-					Toast.makeText(CalculatorVarsActivity.this, error, Toast.LENGTH_LONG).show();
+					Toast.makeText(CalculatorVarsActivity.this, getString(error), Toast.LENGTH_LONG).show();
 					createEditVariableDialog(editedInstance, name, value, description);
 				} else {
 					if ( editedInstance == null ) {
@@ -290,7 +293,7 @@ public class CalculatorVarsActivity extends ListActivity {
 				builder.create().show();
 			} else {
 				adapter.remove(var);
-				final VarsRegister varsRegister = CalculatorModel.getInstance().getVarsRegister();
+				final VarsRegister varsRegister = CalculatorModel.instance.getVarsRegister();
 				varsRegister.remove(var);
 				varsRegister.save(CalculatorVarsActivity.this);
 				CalculatorVarsActivity.this.adapter.notifyDataSetChanged();

src/main/java/org/solovyev/android/calculator/CalculatorView.java

@@ -19,7 +19,9 @@ import android.widget.Toast;
 import bsh.EvalError;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
-import org.solovyev.android.calculator.math.MathEntityType;
+import org.solovyev.android.calculator.math.MathType;
+import org.solovyev.android.calculator.model.CalculatorModel;
+import org.solovyev.android.calculator.model.ParseException;
 import org.solovyev.android.view.CursorControl;
 import org.solovyev.android.view.HistoryControl;
 import org.solovyev.common.utils.MutableObject;
@@ -36,7 +38,7 @@ import org.solovyev.common.utils.history.SimpleHistoryHelper;
 public class CalculatorView implements CursorControl, HistoryControl<CalculatorHistoryState> {
 
 	// millis to wait before evaluation after user edit action
-	public static final int EVAL_DELAY_MILLIS = 500;
+	public static final int EVAL_DELAY_MILLIS = 700;
 
 	@NotNull
 	private final CalculatorEditor editor;
@@ -44,9 +46,6 @@ public class CalculatorView implements CursorControl, HistoryControl<CalculatorH
 	@NotNull
 	private final CalculatorDisplay display;
 
-	@NotNull
-	private final Activity activity;
-
 	@NotNull
 	private final CalculatorModel calculatorModel;
 
@@ -54,7 +53,6 @@ public class CalculatorView implements CursorControl, HistoryControl<CalculatorH
 	private final HistoryHelper<CalculatorHistoryState> history;
 
 	public CalculatorView(@NotNull final Activity activity, @NotNull CalculatorModel calculator) {
-		this.activity = activity;
 		this.calculatorModel = calculator;
 
 		final InputMethodManager imm = (InputMethodManager) activity.getSystemService(Context.INPUT_METHOD_SERVICE);
@@ -159,7 +157,7 @@ public class CalculatorView implements CursorControl, HistoryControl<CalculatorH
 				localDisplay.setText(calculatorModel.evaluate(JsclOperation.numeric, expression));
 			} catch (EvalError e) {
 				handleEvaluationException(expression, localDisplay, e);
-			} catch (CalculatorModel.ParseException e) {
+			} catch (ParseException e) {
 				handleEvaluationException(expression, localDisplay, e);
 			}
 		}
@@ -192,11 +190,11 @@ public class CalculatorView implements CursorControl, HistoryControl<CalculatorH
 				@Override
 				public void doOperation(@NotNull EditText editor) {
 
-					final MathEntityType.Result mathType = MathEntityType.getType(text, 0);
+					final MathType.Result mathType = MathType.getType(text, 0);
 
 					int cursorPositionOffset = 0;
 					final StringBuilder textToBeInserted = new StringBuilder(text);
-					switch (mathType.getMathEntityType()) {
+					switch (mathType.getMathType()) {
 						case function:
 							textToBeInserted.append("()");
 							cursorPositionOffset = -1;

src/main/java/org/solovyev/android/calculator/Preprocessor.java

@@ -1,14 +0,0 @@
-package org.solovyev.android.calculator;
-
-import org.jetbrains.annotations.NotNull;
-
-/**
- * User: serso
- * Date: 9/26/11
- * Time: 12:12 PM
- */
-public interface Preprocessor {
-
-	@NotNull
-	String process(@NotNull String s);
-}

src/main/java/org/solovyev/android/calculator/math/Functions.java

@@ -14,6 +14,11 @@ import java.util.*;
  */
 public class Functions {
 
+	// not intended for instantiation
+	private Functions() {
+		throw new AssertionError("Not allowed!");
+	}
+
 	public final static String SIN = "sin";
 	public final static String SINH = "sinh";
 	public final static String ASIN = "asin";
@@ -45,8 +50,4 @@ public class Functions {
 	public final static Character DEGREE = '°';
 
 	public static final List<Character> allPostfix = Arrays.asList(FACT, DEGREE);
-
-	private Functions() {
-		throw new AssertionError("Not allowed!");
-	}
 }

src/main/java/org/solovyev/android/calculator/math/MathType.java

@@ -6,9 +6,9 @@
 package org.solovyev.android.calculator.math;
 
 import org.jetbrains.annotations.NotNull;
-import org.solovyev.android.calculator.CalculatorModel;
 import org.solovyev.android.calculator.CharacterAtPositionFinder;
 import org.solovyev.android.calculator.StartsWithFinder;
+import org.solovyev.android.calculator.model.CalculatorModel;
 import org.solovyev.common.utils.Finder;
 
 import java.util.Arrays;
@@ -16,7 +16,7 @@ import java.util.List;
 
 import static org.solovyev.common.utils.CollectionsUtils.get;
 
-public enum MathEntityType {
+public enum MathType {
 
 	digit,
 	constant,
@@ -30,7 +30,12 @@ public enum MathEntityType {
 	close_group_symbol,
 	text;
 
-	public static final List<String> constants = Arrays.asList("e", "π", "i");
+	public static final String IMAGINARY_NUMBER = "i";
+	public static final String IMAGINARY_NUMBER_DEF = "sqrt(-1)";
+	public static final String PI = "π";
+	public static final String E = "e";
+
+	public static final List<String> constants = Arrays.asList(E, PI, IMAGINARY_NUMBER);
 
 	public static final List<String> digits = Arrays.asList("0", "1", "2", "3", "4", "5", "6", "7", "8", "9");
 
@@ -57,11 +62,6 @@ public enum MathEntityType {
 	 * @param i	index which points to start of substring
 	 * @return math entity type of substring starting from ith index of specified text
 	 */
-	@NotNull
-	public static MathEntityType getMathEntityType(@NotNull String text, int i) {
-		return getType(text, i).getMathEntityType();
-	}
-
 	@NotNull
 	public static Result getType(@NotNull String text, int i) {
 		if (i < 0) {
@@ -69,7 +69,7 @@ public enum MathEntityType {
 		} else if (i >= text.length() && i != 0) {
 			throw new IllegalArgumentException("I must be less than size of text.");
 		} else if (i == 0 && text.length() == 0) {
-			return new Result(MathEntityType.text, text);
+			return new Result(MathType.text, text);
 		}
 
 		final StartsWithFinder stringStartWithFinder = new StartsWithFinder(text, i);
@@ -77,7 +77,7 @@ public enum MathEntityType {
 
 		String foundString = get(digits, stringStartWithFinder);
 		if (foundString != null) {
-			return new Result(MathEntityType.digit, foundString);
+			return new Result(MathType.digit, foundString);
 		}
 
 		Character foundCharacter = get(dots, characterStartWithFinder);
@@ -102,7 +102,7 @@ public enum MathEntityType {
 
 		foundString = get(groupSymbols, stringStartWithFinder);
 		if (foundString != null) {
-			return new Result(MathEntityType.group_symbols, foundString);
+			return new Result(MathType.group_symbols, foundString);
 		}
 
 		foundCharacter = get(openGroupSymbols, characterStartWithFinder);
@@ -117,39 +117,39 @@ public enum MathEntityType {
 
 		foundString = get(prefixFunctions, stringStartWithFinder);
 		if (foundString != null) {
-			return new Result(MathEntityType.function, foundString);
+			return new Result(MathType.function, foundString);
 		}
 
-		foundString = get(CalculatorModel.getInstance().getVarsRegister().getVarNames(), stringStartWithFinder);
+		foundString = get(CalculatorModel.instance.getVarsRegister().getVarNames(), stringStartWithFinder);
 		if (foundString != null) {
-			return new Result(MathEntityType.constant, foundString);
+			return new Result(MathType.constant, foundString);
 		}
 
-		return new Result(MathEntityType.text, text.substring(i));
+		return new Result(MathType.text, text.substring(i));
 	}
 
 	public static class Result {
 
 		@NotNull
-		private final MathEntityType mathEntityType;
+		private final MathType mathType;
 
 		@NotNull
-		private final String s;
+		private final String match;
 
-		private Result(@NotNull MathEntityType mathEntityType, @NotNull String s){
+		private Result(@NotNull MathType mathType, @NotNull String match){
-			this.mathEntityType = mathEntityType;
+			this.mathType = mathType;
 
-			this.s = s;
+			this.match = match;
 		}
 
 		@NotNull
-		public String getS() {
+		public String getMatch() {
-			return s;
+			return match;
 		}
 
 		@NotNull
-		public MathEntityType getMathEntityType() {
+		public MathType getMathType() {
-			return mathEntityType;
+			return mathType;
 		}
 	}
 

src/main/java/org/solovyev/android/calculator/model/CalculatorModel.java

@@ -0,0 +1,131 @@
+/*
+ * Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+ * For more information, please, contact se.solovyev@gmail.com
+ */
+
+package org.solovyev.android.calculator.model;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.preference.PreferenceManager;
+import bsh.EvalError;
+import bsh.Interpreter;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import org.solovyev.android.calculator.JsclOperation;
+import org.solovyev.common.NumberMapper;
+
+/**
+ * User: serso
+ * Date: 9/12/11
+ * Time: 11:38 PM
+ */
+
+public enum CalculatorModel {
+
+	instance;
+
+	private static final String RESULT_PRECISION_P_KEY = "org.solovyev.android.calculator.CalculatorModel_result_precision";
+	private static final String RESULT_PRECISION_DEFAULT = "5";
+
+	@NotNull
+	private Interpreter interpreter;
+
+	@NotNull
+	private final Object lock = new Object();
+
+	private int numberOfFractionDigits = 5;
+
+	@NotNull
+	public final TextProcessor preprocessor = new ToJsclTextProcessor();
+
+	@NotNull
+	public final TextProcessor postprocessor = new FromJsclTextProcessor();
+
+	@NotNull
+	private final VarsRegisterImpl varsRegister = new VarsRegisterImpl();
+
+	public String evaluate(@NotNull JsclOperation operation, @NotNull String expression) throws EvalError, ParseException {
+		synchronized (lock) {
+			final StringBuilder sb = new StringBuilder();
+
+			sb.append(preprocessor.process(expression));
+
+			//Log.d(CalculatorModel.class.getName(), "Preprocessed expression: " + preprocessedExpression);
+
+			final Object evaluationObject = interpreter.eval(ToJsclTextProcessor.wrap(operation, sb.toString()));
+
+			return postprocessor.process(String.valueOf(evaluationObject).trim());
+		}
+	}
+
+	public int getNumberOfFractionDigits() {
+		return numberOfFractionDigits;
+	}
+
+	public void setNumberOfFractionDigits(int numberOfFractionDigits) {
+		this.numberOfFractionDigits = numberOfFractionDigits;
+	}
+
+	public void init(@Nullable Context context) throws EvalError {
+		synchronized (lock) {
+			reset(context);
+			resetInterpreter();
+		}
+	}
+
+	public void reset(@Nullable Context context) {
+		synchronized (lock) {
+			if (context != null) {
+				final SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
+
+				final NumberMapper<Integer> integerNumberMapper = new NumberMapper<Integer>(Integer.class);
+				//noinspection ConstantConditions
+				this.setNumberOfFractionDigits(integerNumberMapper.parseValue(preferences.getString(RESULT_PRECISION_P_KEY, RESULT_PRECISION_DEFAULT)));
+			}
+
+			varsRegister.init(context);
+		}
+	}
+
+	public void resetInterpreter() {
+		synchronized (lock) {
+			try {
+				interpreter = new Interpreter();
+				interpreter.eval(ToJsclTextProcessor.wrap(JsclOperation.importCommands, "/jscl/editorengine/commands"));
+			} catch (EvalError evalError) {
+				throw new RuntimeException(evalError);
+			}
+		}
+	}
+
+	@NotNull
+	public VarsRegister getVarsRegister() {
+		return varsRegister;
+	}
+
+	/*	private String commands(String str) {
+			return commands(str, false);
+		}
+
+
+		private void exec(String str) throws EvalError {
+			interpreter.eval(str);
+		}
+
+		private String eval(String str) throws EvalError {
+			return interpreter.eval(commands(str)).toString();
+		}
+
+		private String commands(String str, boolean found) {
+			for (int i = 0; i < cmds.length; i++) {
+				int n = str.length() - cmds[i].length() - 1;
+				if (n >= 0 && (" " + cmds[i].toLowerCase()).equals(str.substring(n)))
+					return commands(str.substring(0, n), true) + "." + cmds[i] + "()";
+			}
+			str = str.replaceAll("\n", "");
+			return found ? "jscl.math.Expression.valueOf(\"" + str + "\")" : str;
+		}
+
+		private static final String cmds[] = new String[]{"expand", "factorize", "elementary", "simplify", "numeric", "toMathML", "toJava"};*/
+}

src/main/java/org/solovyev/android/calculator/model/FromJsclTextProcessor.java

@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+ * For more information, please, contact se.solovyev@gmail.com
+ * or visit http://se.solovyev.org
+ */
+
+package org.solovyev.android.calculator.model;
+
+import org.jetbrains.annotations.NotNull;
+import org.solovyev.android.calculator.math.MathType;
+import org.solovyev.common.utils.MathUtils;
+import org.solovyev.util.math.Complex;
+
+/**
+ * User: serso
+ * Date: 10/6/11
+ * Time: 9:48 PM
+ */
+class FromJsclTextProcessor implements TextProcessor {
+
+	@NotNull
+	@Override
+	public String process(@NotNull String s) throws ParseException {
+		String result = null;
+
+		try {
+			result = String.valueOf(round(s));
+		} catch (NumberFormatException e) {
+			if (result.contains(MathType.IMAGINARY_NUMBER_DEF)) {
+				try {
+					result = createResultForComplexNumber(result.replace(MathType.IMAGINARY_NUMBER_DEF, MathType.IMAGINARY_NUMBER));
+				} catch (NumberFormatException e1) {
+					// throw original one
+					throw new ParseException(e);
+				}
+
+			} else {
+				throw new ParseException(e);
+			}
+		}
+
+		return result;
+	}
+
+	protected String createResultForComplexNumber(@NotNull final String s) {
+		final Complex complex = new Complex();
+
+		String result = "";
+		// may be it's just complex number
+		int plusIndex = s.lastIndexOf("+");
+		if (plusIndex >= 0) {
+			complex.setReal(round(s.substring(0, plusIndex)));
+			result += complex.getReal();
+			result += "+";
+		} else {
+			plusIndex = s.lastIndexOf("-");
+			if (plusIndex >= 0) {
+				complex.setReal(round(s.substring(0, plusIndex)));
+				result += complex.getReal();
+				result += "-";
+			}
+		}
+
+
+		int multiplyIndex = s.indexOf("*");
+		if (multiplyIndex >= 0) {
+			complex.setImaginary(round(s.substring(plusIndex >= 0 ? plusIndex + 1 : 0, multiplyIndex)));
+			result += complex.getImaginary();
+
+		}
+
+		result += MathType.IMAGINARY_NUMBER;
+
+		return result;
+	}
+
+	private Double round(@NotNull String result) {
+		final Double dResult = Double.valueOf(result);
+		return MathUtils.round(dResult, CalculatorModel.instance.getNumberOfFractionDigits());
+	}
+}

src/main/java/org/solovyev/android/calculator/model/ParseException.java

@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+ * For more information, please, contact se.solovyev@gmail.com
+ * or visit http://se.solovyev.org
+ */
+
+package org.solovyev.android.calculator.model;
+
+import org.solovyev.common.exceptions.SersoException;
+
+/**
+* User: serso
+* Date: 10/6/11
+* Time: 9:25 PM
+*/
+public class ParseException extends SersoException {
+	public ParseException(Throwable cause) {
+		super(cause);
+	}
+}

src/main/java/org/solovyev/android/calculator/model/TextProcessor.java

@@ -0,0 +1,14 @@
+package org.solovyev.android.calculator.model;
+
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * User: serso
+ * Date: 9/26/11
+ * Time: 12:12 PM
+ */
+public interface TextProcessor {
+
+	@NotNull
+	String process(@NotNull String s) throws ParseException;
+}

src/main/java/org/solovyev/android/calculator/model/ToJsclTextProcessor.java

@@ -4,17 +4,19 @@
  * or visit http://se.solovyev.org
  */
 
-package org.solovyev.android.calculator;
+package org.solovyev.android.calculator.model;
 
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
+import org.solovyev.android.calculator.JsclOperation;
+import org.solovyev.android.calculator.StartsWithFinder;
 import org.solovyev.android.calculator.math.Functions;
-import org.solovyev.android.calculator.math.MathEntityType;
+import org.solovyev.android.calculator.math.MathType;
 import org.solovyev.common.utils.CollectionsUtils;
 import org.solovyev.common.utils.FilterType;
 import org.solovyev.common.utils.Finder;
 
-public class ToJsclPreprocessor implements Preprocessor {
+class ToJsclTextProcessor implements TextProcessor {
 
 	@Override
 	@NotNull
@@ -23,26 +25,26 @@ public class ToJsclPreprocessor implements Preprocessor {
 		final StartsWithFinder startsWithFinder = new StartsWithFinder(s, 0);
 		final StringBuilder sb = new StringBuilder();
 
-		MathEntityType.Result mathTypeResult = null;
+		MathType.Result mathTypeResult = null;
 		for (int i = 0; i < s.length(); i++) {
 			char ch = s.charAt(i);
 			startsWithFinder.setI(i);
 
 			mathTypeResult = checkMultiplicationSignBeforeFunction(sb, s, i, mathTypeResult);
 
-			final MathEntityType mathType = mathTypeResult.getMathEntityType();
+			final MathType mathType = mathTypeResult.getMathType();
-			if (mathType == MathEntityType.open_group_symbol) {
+			if (mathType == MathType.open_group_symbol) {
 				sb.append('(');
-			} else if (mathType == MathEntityType.close_group_symbol) {
+			} else if (mathType == MathType.close_group_symbol) {
 				sb.append(')');
 			} else if (ch == '×' || ch == '∙') {
 				sb.append("*");
-			} else if ( mathType == MathEntityType.function  ){
+			} else if ( mathType == MathType.function  ){
-				sb.append(toJsclFunction(mathTypeResult.getS()));
+				sb.append(toJsclFunction(mathTypeResult.getMatch()));
-				i += mathTypeResult.getS().length() - 1;
+				i += mathTypeResult.getMatch().length() - 1;
-			} else if ( mathType == MathEntityType.constant ) {
+			} else if ( mathType == MathType.constant ) {
-				sb.append(mathTypeResult.getS());
+				sb.append(mathTypeResult.getMatch());
-				i += mathTypeResult.getS().length() - 1;
+				i += mathTypeResult.getMatch().length() - 1;
 			} else {
 				sb.append(ch);
 			}
@@ -59,11 +61,11 @@ public class ToJsclPreprocessor implements Preprocessor {
 			startsWithFinder.setI(i);
 
 			int offset = 0;
-			String functionName = CollectionsUtils.get(MathEntityType.prefixFunctions, startsWithFinder);
+			String functionName = CollectionsUtils.get(MathType.prefixFunctions, startsWithFinder);
 			if (functionName == null) {
-				String varName = CollectionsUtils.get(CalculatorModel.getInstance().getVarsRegister().getVarNames(), startsWithFinder);
+				String varName = CollectionsUtils.get(CalculatorModel.instance.getVarsRegister().getVarNames(), startsWithFinder);
 				if (varName != null) {
-					final Var var = CalculatorModel.getInstance().getVarsRegister().getVar(varName);
+					final Var var = CalculatorModel.instance.getVarsRegister().getVar(varName);
 					if (var != null) {
 						result.append(var.getValue());
 						offset = varName.length();
@@ -86,10 +88,10 @@ public class ToJsclPreprocessor implements Preprocessor {
 	}
 
 	private void replaceVariables(StringBuilder sb, String s, int i, @NotNull StartsWithFinder startsWithFinder) {
-		for (Var var : CalculatorModel.getInstance().getVarsRegister().getVars()) {
+		for (Var var : CalculatorModel.instance.getVarsRegister().getVars()) {
 			if (!var.isSystem()) {
 				if (s.startsWith(var.getName(), i)) {
-					if (CollectionsUtils.get(MathEntityType.prefixFunctions, startsWithFinder) == null) {
+					if (CollectionsUtils.get(MathType.prefixFunctions, startsWithFinder) == null) {
 					}
 				}
 			}
@@ -103,13 +105,13 @@ public class ToJsclPreprocessor implements Preprocessor {
 		int result = position;
 		for (; result >= 0; result--) {
 
-			final MathEntityType mathEntityType = MathEntityType.getMathEntityType(s, result);
+			final MathType mathType = MathType.getType(s, result).getMathType();
 
-			if (CollectionsUtils.contains(mathEntityType, MathEntityType.digit, MathEntityType.dot)) {
+			if (CollectionsUtils.contains(mathType, MathType.digit, MathType.dot)) {
 				// continue
-			} else if (mathEntityType == MathEntityType.close_group_symbol) {
+			} else if (mathType == MathType.close_group_symbol) {
 				numberOfOpenGroups++;
-			} else if (mathEntityType == MathEntityType.open_group_symbol) {
+			} else if (mathType == MathType.open_group_symbol) {
 				numberOfOpenGroups--;
 			} else {
 				if (stop(s, numberOfOpenGroups, result)) break;
@@ -124,9 +126,9 @@ public class ToJsclPreprocessor implements Preprocessor {
 			if (i > 0) {
 				final EndsWithFinder endsWithFinder = new EndsWithFinder(s);
 				endsWithFinder.setI(i + 1);
-				if (!CollectionsUtils.contains(MathEntityType.prefixFunctions, FilterType.included, endsWithFinder)) {
+				if (!CollectionsUtils.contains(MathType.prefixFunctions, FilterType.included, endsWithFinder)) {
-					MathEntityType type = MathEntityType.getMathEntityType(s, i);
+					MathType type = MathType.getType(s, i).getMathType();
-					if (type != MathEntityType.constant) {
+					if (type != MathType.constant) {
 						return true;
 					}
 				}
@@ -175,31 +177,31 @@ public class ToJsclPreprocessor implements Preprocessor {
 	}
 
 	@NotNull
-	private static MathEntityType.Result checkMultiplicationSignBeforeFunction(@NotNull StringBuilder sb,
+	private static MathType.Result checkMultiplicationSignBeforeFunction(@NotNull StringBuilder sb,
 																		@NotNull String s,
 																		int i,
-																		@Nullable MathEntityType.Result mathTypeBeforeResult) {
+																		@Nullable MathType.Result mathTypeBeforeResult) {
-		MathEntityType.Result result = MathEntityType.getType(s, i);
+		MathType.Result result = MathType.getType(s, i);
 
 		if (i > 0) {
 
-			final MathEntityType mathType = result.getMathEntityType();
+			final MathType mathType = result.getMathType();
 			assert mathTypeBeforeResult != null;
-			final MathEntityType mathTypeBefore = mathTypeBeforeResult.getMathEntityType();
+			final MathType mathTypeBefore = mathTypeBeforeResult.getMathType();
 
-			if (mathTypeBefore == MathEntityType.constant || (mathTypeBefore != MathEntityType.binary_operation &&
+			if (mathTypeBefore == MathType.constant || (mathTypeBefore != MathType.binary_operation &&
-					mathTypeBefore != MathEntityType.unary_operation &&
+					mathTypeBefore != MathType.unary_operation &&
-					mathTypeBefore != MathEntityType.function &&
+					mathTypeBefore != MathType.function &&
-					mathTypeBefore != MathEntityType.open_group_symbol)) {
+					mathTypeBefore != MathType.open_group_symbol)) {
 
-				if (mathType == MathEntityType.constant) {
+				if (mathType == MathType.constant) {
 					sb.append("*");
-				} else if (mathType == MathEntityType.open_group_symbol && mathTypeBefore != null) {
+				} else if (mathType == MathType.open_group_symbol && mathTypeBefore != null) {
 					sb.append("*");
-				} else if (mathType == MathEntityType.digit && ((mathTypeBefore != MathEntityType.digit && mathTypeBefore != MathEntityType.dot) || mathTypeBefore == MathEntityType.constant)) {
+				} else if (mathType == MathType.digit && ((mathTypeBefore != MathType.digit && mathTypeBefore != MathType.dot) || mathTypeBefore == MathType.constant)) {
 					sb.append("*");
 				} else {
-					for (String function : MathEntityType.prefixFunctions) {
+					for (String function : MathType.prefixFunctions) {
 						if (s.startsWith(function, i)) {
 							sb.append("*");
 							break;

src/main/java/org/solovyev/android/calculator/model/Var.java

@@ -4,7 +4,7 @@
  * or visit http://se.solovyev.org
  */
 
-package org.solovyev.android.calculator;
+package org.solovyev.android.calculator.model;
 
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;

src/main/java/org/solovyev/android/calculator/model/Vars.java

@@ -1,4 +1,4 @@
-package org.solovyev.android.calculator;
+package org.solovyev.android.calculator.model;
 
 import org.simpleframework.xml.ElementList;
 import org.simpleframework.xml.Root;

src/main/java/org/solovyev/android/calculator/model/VarsRegister.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+ * For more information, please, contact se.solovyev@gmail.com
+ * or visit http://se.solovyev.org
+ */
+
+package org.solovyev.android.calculator.model;
+
+import android.content.Context;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.List;
+
+/**
+ * User: serso
+ * Date: 10/6/11
+ * Time: 9:31 PM
+ */
+public interface VarsRegister {
+
+	@NotNull
+	List<Var> getVars();
+
+	@NotNull
+	List<Var> getSystemVars();
+
+	Var addVar(@Nullable String name, @NotNull Var.Builder builder);
+
+	void remove(@NotNull Var var);
+
+	@NotNull
+	List<String> getVarNames();
+
+	@Nullable
+	Var getVar(@NotNull String name);
+
+	boolean contains(@NotNull String name);
+
+	void save(@NotNull Context context);
+}

src/main/java/org/solovyev/android/calculator/model/VarsRegisterImpl.java

@@ -4,7 +4,7 @@
  * or visit http://se.solovyev.org
  */
 
-package org.solovyev.android.calculator;
+package org.solovyev.android.calculator.model;
 
 import android.content.Context;
 import android.content.SharedPreferences;
@@ -13,8 +13,9 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.simpleframework.xml.Serializer;
 import org.simpleframework.xml.core.Persister;
+import org.solovyev.android.calculator.R;
 import org.solovyev.android.calculator.math.MathEntityComparator;
-import org.solovyev.android.calculator.math.MathEntityType;
+import org.solovyev.android.calculator.math.MathType;
 import org.solovyev.common.utils.CollectionsUtils;
 import org.solovyev.common.utils.Finder;
 
@@ -26,7 +27,7 @@ import java.util.*;
  * Date: 9/29/11
  * Time: 4:57 PM
  */
-public class VarsRegister {
+class VarsRegisterImpl implements VarsRegister {
 
 	@NotNull
 	private final List<Var> vars = new ArrayList<Var>();
@@ -34,16 +35,22 @@ public class VarsRegister {
 	@NotNull
 	private final List<Var> systemVars = new ArrayList<Var>();
 
+	protected VarsRegisterImpl() {
+	}
+
+	@Override
 	@NotNull
 	public List<Var> getVars() {
 		return Collections.unmodifiableList(vars);
 	}
 
+	@Override
 	@NotNull
 	public List<Var> getSystemVars() {
 		return Collections.unmodifiableList(systemVars);
 	}
 
+	@Override
 	public Var addVar(@Nullable String name, @NotNull Var.Builder builder) {
 		final Var var = builder.create();
 
@@ -58,12 +65,14 @@ public class VarsRegister {
 		return varFromRegister;
 	}
 
-	public void remove (@NotNull Var var) {
+	@Override
+	public void remove(@NotNull Var var) {
 		this.vars.remove(var);
 	}
 
+	@Override
 	@NotNull
-	public List<String> getVarNames () {
+	public List<String> getVarNames() {
 		final List<String> result = new ArrayList<String>();
 
 		for (Var var : vars) {
@@ -75,6 +84,7 @@ public class VarsRegister {
 		return result;
 	}
 
+	@Override
 	@Nullable
 	public Var getVar(@NotNull final String name) {
 		return CollectionsUtils.get(vars, new Finder<Var>() {
@@ -85,6 +95,7 @@ public class VarsRegister {
 		});
 	}
 
+	@Override
 	public boolean contains(@NotNull final String name) {
 		return CollectionsUtils.get(vars, new Finder<Var>() {
 			@Override
@@ -107,7 +118,7 @@ public class VarsRegister {
 		vars.addAll(result);
 	}
 
-	public synchronized void load(@Nullable Context context) {
+	synchronized void init(@Nullable Context context) {
 
 		this.vars.clear();
 		this.systemVars.clear();
@@ -128,19 +139,32 @@ public class VarsRegister {
 		}
 
 
-		for (String systemVarName : MathEntityType.constants) {
+		for (String systemVarName : MathType.constants) {
 
-			final Var systemVar;
+			final Var.Builder builder;
-			if ( systemVarName.equals("e") ){
+			final Integer varDescription;
-				systemVar = new Var.Builder(systemVarName, Math.E).setSystem(true).create();
+
-			} else if (systemVarName.equals("π")) {
+			if ( systemVarName.equals(MathType.E) ){
-				systemVar = new Var.Builder(systemVarName, Math.PI).setSystem(true).create();
+				builder = new Var.Builder(systemVarName, Math.E);
-			} else if (systemVarName.equals("i")) {
+				varDescription = R.string.c_e_description;
-				systemVar = new Var.Builder(systemVarName, "sqrt(-1)").setSystem(true).create();
+			} else if (systemVarName.equals(MathType.PI)) {
+				builder = new Var.Builder(systemVarName, Math.PI);
+				varDescription = R.string.c_pi_description;
+			} else if (systemVarName.equals(MathType.IMAGINARY_NUMBER)) {
+				builder = new Var.Builder(systemVarName, MathType.IMAGINARY_NUMBER_DEF);
+				varDescription = R.string.c_i_description;
 			} else {
 				throw new IllegalArgumentException(systemVarName + " is not supported yet!");
 			}
 
+			builder.setSystem(true);
+
+			if (context != null) {
+				builder.setDescription(context.getString(varDescription));
+			}
+
+			final Var systemVar = builder.create();
+
 			systemVars.add(systemVar);
 			if (!vars.contains(systemVar)) {
 				vars.add(systemVar);
@@ -153,6 +177,7 @@ public class VarsRegister {
 		}*/
 	}
 
+	@Override
 	public synchronized void save(@NotNull Context context) {
 		final SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(context);
 		final SharedPreferences.Editor editor = settings.edit();

src/main/java/org/solovyev/android/view/AutoResizeTextView.java

@@ -80,12 +80,12 @@ public class AutoResizeTextView extends TextView {
     }
 
     /**
-     * When text changes, set the force resize flag to true and reset the text size.
+     * When text changes, set the force resize flag to true and resetInterpreter the text size.
      */
     @Override
     protected void onTextChanged(final CharSequence text, final int start, final int before, final int after) {
         mNeedsResize = true;
-        // Since this view may be reused, it is good to reset the text size
+        // Since this view may be reused, it is good to resetInterpreter the text size
         resetTextSize();
     }
 

src/test/java/org/solovyev/android/calculator/math/MathEntityTypeTest.java

@@ -1,45 +0,0 @@
-/*
- * Copyright (c) 2009-2011. Created by serso aka se.solovyev.
- * For more information, please, contact se.solovyev@gmail.com
- * or visit http://se.solovyev.org
- */
-
-package org.solovyev.android.calculator.math;
-
-import junit.framework.Assert;
-import org.junit.BeforeClass;
-import org.junit.Test;
-import org.solovyev.android.calculator.CalculatorModel;
-
-/**
- * User: serso
- * Date: 10/5/11
- * Time: 1:25 AM
- */
-public class MathEntityTypeTest {
-
-	@BeforeClass
-	public static void setUp() throws Exception {
-		CalculatorModel.init(null);
-	}
-
-	@Test
-	public void testGetType() throws Exception {
-		Assert.assertEquals(MathEntityType.function, MathEntityType.getType("sin", 0).getMathEntityType());
-		Assert.assertEquals(MathEntityType.text, MathEntityType.getType("sn", 0).getMathEntityType());
-		Assert.assertEquals(MathEntityType.text, MathEntityType.getType("s", 0).getMathEntityType());
-		Assert.assertEquals(MathEntityType.text, MathEntityType.getType("", 0).getMathEntityType());
-
-		try {
-			Assert.assertEquals(MathEntityType.text, MathEntityType.getType("22", -1).getMathEntityType());
-			Assert.fail();
-		} catch (IllegalArgumentException e) {
-		}
-
-		try {
-			Assert.assertEquals(MathEntityType.text, MathEntityType.getType("22", 2).getMathEntityType());
-			Assert.fail();
-		} catch (IllegalArgumentException e) {
-		}
-	}
-}

src/test/java/org/solovyev/android/calculator/math/MathTypeTest.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+ * For more information, please, contact se.solovyev@gmail.com
+ * or visit http://se.solovyev.org
+ */
+
+package org.solovyev.android.calculator.math;
+
+import junit.framework.Assert;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.solovyev.android.calculator.model.CalculatorModel;
+
+/**
+ * User: serso
+ * Date: 10/5/11
+ * Time: 1:25 AM
+ */
+public class MathTypeTest {
+
+	@BeforeClass
+	public static void setUp() throws Exception {
+		CalculatorModel.instance.init(null);
+	}
+
+	@Test
+	public void testGetType() throws Exception {
+		Assert.assertEquals(MathType.function, MathType.getType("sin", 0).getMathType());
+		Assert.assertEquals(MathType.text, MathType.getType("sn", 0).getMathType());
+		Assert.assertEquals(MathType.text, MathType.getType("s", 0).getMathType());
+		Assert.assertEquals(MathType.text, MathType.getType("", 0).getMathType());
+
+		try {
+			Assert.assertEquals(MathType.text, MathType.getType("22", -1).getMathType());
+			Assert.fail();
+		} catch (IllegalArgumentException e) {
+		}
+
+		try {
+			Assert.assertEquals(MathType.text, MathType.getType("22", 2).getMathType());
+			Assert.fail();
+		} catch (IllegalArgumentException e) {
+		}
+	}
+}

src/test/java/org/solovyev/android/calculator/model/CalculatorModelTest.java

@@ -3,12 +3,13 @@
  * For more information, please, contact se.solovyev@gmail.com
  */
 
-package org.solovyev.android.calculator;
+package org.solovyev.android.calculator.model;
 
 import bsh.EvalError;
 import org.junit.Assert;
 import org.junit.BeforeClass;
 import org.junit.Test;
+import org.solovyev.android.calculator.JsclOperation;
 
 /**
  * User: serso
@@ -19,12 +20,12 @@ public class CalculatorModelTest {
 
 	@BeforeClass
 	public static void setUp() throws Exception {
-		CalculatorModel.init(null);
+		CalculatorModel.instance.init(null);
 	}
 
 	@Test
 	public void testEvaluate() throws Exception {
-		final CalculatorModel cm = CalculatorModel.getInstance();
+		final CalculatorModel cm = CalculatorModel.instance;
 
 		Assert.assertEquals("4.0", cm.evaluate(JsclOperation.numeric, "2+2"));
 		Assert.assertEquals("-0.7568", cm.evaluate(JsclOperation.numeric, "sin(4)"));
@@ -47,7 +48,7 @@ public class CalculatorModelTest {
 		Assert.assertEquals("-3.41007+3.41007i", cm.evaluate(JsclOperation.numeric, "(5tan(2i)+2i)/(1-i)"));
 		Assert.assertEquals("-0.1-0.2i", cm.evaluate(JsclOperation.numeric, "(1-i)/(2+6i)"));
 
-		CalculatorModel.getInstance().getVarsRegister().addVar(null, new Var.Builder("si", 5d));
+		CalculatorModel.instance.getVarsRegister().addVar(null, new Var.Builder("si", 5d));
 		Assert.assertEquals("5.0", cm.evaluate(JsclOperation.numeric, "si"));
 		try {
 			cm.evaluate(JsclOperation.numeric, "sin");
@@ -60,17 +61,17 @@ public class CalculatorModelTest {
 		Assert.assertEquals("-23.97311", cm.evaluate(JsclOperation.numeric, "si*sin(5)si"));
 		Assert.assertEquals("-3.30879", cm.evaluate(JsclOperation.numeric, "sisin(5si)si"));
 
-		CalculatorModel.getInstance().getVarsRegister().addVar(null, new Var.Builder("s", 1d));
+		CalculatorModel.instance.getVarsRegister().addVar(null, new Var.Builder("s", 1d));
 		Assert.assertEquals("5.0", cm.evaluate(JsclOperation.numeric, "si"));
 
-		CalculatorModel.getInstance().getVarsRegister().addVar(null, new Var.Builder("k", 3.5d));
+		CalculatorModel.instance.getVarsRegister().addVar(null, new Var.Builder("k", 3.5d));
-		CalculatorModel.getInstance().getVarsRegister().addVar(null, new Var.Builder("k1", 4d));
+		CalculatorModel.instance.getVarsRegister().addVar(null, new Var.Builder("k1", 4d));
 		Assert.assertEquals("4.0", cm.evaluate(JsclOperation.numeric, "k11"));
 	}
 
 	@Test
 	public void testComplexNumbers() throws Exception {
-		final CalculatorModel cm = CalculatorModel.getInstance();
+		final FromJsclTextProcessor cm = new FromJsclTextProcessor();
 
 		Assert.assertEquals("1.22133+23123.0i", cm.createResultForComplexNumber("1.22133232+23123*i"));
 		Assert.assertEquals("1.22133+1.2i", cm.createResultForComplexNumber("1.22133232+1.2*i"));

src/test/java/org/solovyev/android/calculator/model/ToJsclPreprocessorTest.java

@@ -4,7 +4,7 @@
  * or visit http://se.solovyev.org
  */
 
-package org.solovyev.android.calculator;
+package org.solovyev.android.calculator.model;
 
 import org.junit.Assert;
 import org.junit.Test;
@@ -18,7 +18,7 @@ public class ToJsclPreprocessorTest {
 
 	@Test
 	public void testProcess() throws Exception {
-		final ToJsclPreprocessor preprocessor = new ToJsclPreprocessor();
+		final ToJsclTextProcessor preprocessor = new ToJsclTextProcessor();
 
 		Assert.assertEquals( "sin(4)*cos(5)", preprocessor.process("sin(4)cos(5)"));
 		Assert.assertEquals( "pi*sin(4)*pi*cos(sqrt(5))", preprocessor.process("πsin(4)πcos(√(5))"));
@@ -30,7 +30,7 @@ public class ToJsclPreprocessorTest {
 
 	@Test
 	public void testPostfixFunctionsProcessing() throws Exception {
-		final ToJsclPreprocessor preprocessor = new ToJsclPreprocessor();
+		final ToJsclTextProcessor preprocessor = new ToJsclTextProcessor();
 
 		Assert.assertEquals(-1, preprocessor.getPostfixFunctionStart("5!", 0));
 		Assert.assertEquals(0, preprocessor.getPostfixFunctionStart("!", 0));