Implemented localization of library messages (#3).

Author: gianluca-nitti

app/build.gradle

@@ -22,7 +22,7 @@ android {
 dependencies {
     compile fileTree(include: ['*.jar'], dir: 'libs')
     testCompile 'junit:junit:4.12'
-    compile 'com.github.gianluca-nitti:java-expr-eval:v3.0'
+    compile 'com.github.gianluca-nitti:java-expr-eval:v3.1'
     compile 'com.android.support:appcompat-v7:25+'
     compile 'com.android.support:support-v4:25+'
 }

app/src/main/java/com/github/gianlucanitti/expreval/ExprEval.java

@@ -38,6 +38,7 @@ protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_expr_eval);
         setSupportActionBar((Toolbar)findViewById(R.id.my_toolbar));
+        LibraryLocalizer.localize(this);
         in = (EditText) findViewById(R.id.inputText);
         out = (TextView) findViewById(R.id.outputText);
         out.setMovementMethod(new ScrollingMovementMethod());

app/src/main/java/com/github/gianlucanitti/expreval/ExprEvalDialog.java

@@ -18,6 +18,7 @@ public class ExprEvalDialog extends AppCompatActivity implements View.OnClickLis
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_expr_eval_dialog);
+        LibraryLocalizer.localize(this);
         View okButton = findViewById(R.id.evalDialogOK);
         View cancelButton = findViewById(R.id.evalDialogCancel);
         okButton.setOnClickListener(this);

app/src/main/java/com/github/gianlucanitti/expreval/LibraryLocalizer.java

@@ -0,0 +1,40 @@
+package com.github.gianlucanitti.expreval;
+
+import android.content.Context;
+import static com.github.gianlucanitti.javaexpreval.LocalizationHelper.*;
+
+public class LibraryLocalizer {
+
+    private static void setMessageResource(Context c, Message m, int id){
+        setMessage(m, c.getString(id));
+    }
+
+    public static void localize(Context c){
+        setMessageResource(c, Message.CONTEXT_CLEARED, R.string.contextCleared);
+        setMessageResource(c, Message.EMPTY_EXPR, R.string.emptyExpr);
+        setMessageResource(c, Message.EMPTY_SYM_NAME, R.string.emptySymName);
+        setMessageResource(c, Message.ERROR_PREFIX, R.string.errorPrefix);
+        setMessageResource(c, Message.EVAL_STEP, R.string.evalStep);
+        setMessageResource(c, Message.EXPR_END_REACHED, R.string.exprEndReached);
+        setMessageResource(c, Message.FAILED_STORE_RESULT, R.string.failedStoreResult);
+        setMessageResource(c, Message.FUNC_ASSIGNED, R.string.functionNewDef);
+        setMessageResource(c, Message.INCORRECT_DELETE, R.string.incorrectDelete);
+        setMessageResource(c, Message.INTERACTIVE_HELP, R.string.interactiveHelp);
+        setMessageResource(c, Message.INVALID_OPERATOR, R.string.invalidOperator);
+        setMessageResource(c, Message.INVALID_SYM_NAME, R.string.invalidSymName);
+        setMessageResource(c, Message.ONLY_ONE_EQUALITY, R.string.onlyOneEquality);
+        setMessageResource(c, Message.OPERATOR_EXPECTED, R.string.operatorExpected);
+        setMessageResource(c, Message.OPERATOR_FOUND, R.string.operatorFound);
+        setMessageResource(c, Message.PARENTHESIS_MISMATCH, R.string.parenthesisMismatch);
+        setMessageResource(c, Message.READONLY_FUNC, R.string.readonlyFunc);
+        setMessageResource(c, Message.READONLY_VAR, R.string.readonlyVar);
+        setMessageResource(c, Message.RESERVED_WORD, R.string.reservedWord);
+        setMessageResource(c, Message.REWRITE_STEP, R.string.rewriteStep);
+        setMessageResource(c, Message.UNDEFINED_FUNC, R.string.undefinedFunc);
+        setMessageResource(c, Message.UNDEFINED_VAR, R.string.undefinedVar);
+        setMessageResource(c, Message.UNKNOWN_CHAR, R.string.unknownChar);
+        setMessageResource(c, Message.VAR_ASSIGNED, R.string.varNewValue);
+        setMessageResource(c, Message.VAR_DELETED, R.string.contextItemDeleted);
+    }
+
+}

app/src/main/res/values/strings.xml

@@ -7,7 +7,7 @@
     <string name="exprInputHint" >Type expression or command</string>
     <string name="evalBtn">Evaluate</string>
     <string name="clearContextPrompt">Do you want to delete all non-readonly functions and variables?</string>
-    <string name="contextCleared">All non-readonly variables and functions have been cleared.</string>
+    <string name="contextCleared">All non-readonly variables and functions have been deleted.</string>
     <string name="helpMessage">
         In the input box you can type expressions, variable or function assignments (like &quot;a=5&quot; or &quot;log(x,b)=log(x)/log(b)&quot;) and commands.
         The available commands are &quot;help&quot;, &quot;context&quot;, &quot;clear&quot; and &quot;exit&quot;. Type &quot;help&quot; in the input box for more detailed instructions. In the output box, results are shown in &lt;font color=&quot;green&quot;&gt;green&lt;/font&gt; and errors in &lt;font color=&quot;red&quot;&gt;red&lt;/font&gt;.
@@ -29,23 +29,23 @@
         <item>Add function</item>
     </string-array>
     <string name="contextItemDeletePrompt">Do you want to delete "%s" ?</string>
-    <string name="contextItemDeleted">"%s" has been deleted</string>
+    <string name="contextItemDeleted">"%s" has been deleted.</string>
 
     <!-- both EditFunctionDialogFragment and EditVariableDialogFragment -->
     <string name="name">Name</string>
     <string name="readonlyCheckbox">Read-only (if checked, you won\'t be able to edit or delete this until the application is restarted.)</string>
 
     <!-- EditVariableDialogFragment -->
     <string name="value">Value</string>
-    <string name="varNewValue" formatted="false">%1s is now %2s.</string>
+    <string name="varNewValue">%1$s is now %2$s.</string>
 
     <!-- EditFunctionDialogFragment -->
     <string name="expression">Expression</string>
     <string name="arguments">Arguments (tap to remove)</string>
     <string name="argumentHint">Type argument name</string>
     <string name="addArgument">Add argument</string>
     <string name="invalidArgName">Invalid argument name</string>
-    <string name="functionNewDef" formatted="false">%1s is now defined as %2s.</string>
+    <string name="functionNewDef">%1$s is now defined as %2$s.</string>
 
     <!-- ExprEvalDialog activity -->
     <string name="expressionColon">Expression: </string>
@@ -54,4 +54,38 @@
     <string name="okToReplace">Tap OK to replace the expression with the result.</string>
     <string name="close">Close</string>
     <string name="evalFailed"> evaluation failed.</string>
+
+    <!-- Various messages used by the java-expr-eval library (https://github.com/gianluca-nitti/java-expr-eval) -->
+    <string name="emptyExpr">An empty expression was found.</string>
+    <string name="emptySymName">The empty string isn\'t a valid symbol identifier.</string>
+    <string name="errorPrefix">Expression error: %s</string>
+    <string name="evalStep">%1$s evaluates to %2$s</string>
+    <string name="exprEndReached">A sub-expression was expected, but the end of the expression was reached.</string>
+    <string name="failedStoreResult">Warning: failed to store result. Reason: %s</string>
+    <string name="incorrectDelete">Incorrect syntax. To delete a function, the number of arguments must be specified (e.g. "fun(2)=" to delete "fun(x, y)").</string>
+    <string name="interactiveHelp">
+        Accepted statements are expressions, assignments and commands.
+        An expression can be formed by integer or decimal numbers, the +,-,*,/,^ binary operators, variables, functions and parenthesis.
+        A variable is a string of one or more letters and/or underscores. Variables can\'t be named as commands, which are reserved words.
+        When an expression is successfully evaluated, it\'s result is displayed and automatically assigned to the "ans" variable, so it can be accessed from the next statement.
+        A variable assignment is formed by a variable name followed by the = symbol and an expression, which is evaluated and bound to that variable.
+        An empty assignment (in the form "someVariable=") deletes the variable.
+        A function assignment is formed by a function name and its parameters, followed by the = symbol and an expression, which is bound to that function, e.g."sum(x,y)=x+y".
+        A function can be deleted with an empty assignment; the number of arguments must be specified, e.g. "sum(2)=" to delete the function "sum" defined on two arguments.
+        An assignment (of variable or function) can be prepended with the "readonly" word to prevent it to be modified or deleted, e.g. "readonly x=1", "readonly square(a)=a^2".
+        The commands are: context (prints all the defined variables and functions), clear (deletes all the non-readonly variables and functions), help (shows this message) and exit (stops reading input).
+    </string>
+    <string name="invalidOperator">Unknown operator \'%s\'.</string>
+    <string name="invalidSymName">"%1$s" isn\'t a valid symbol name because it contains the \'%2$s\' character.</string>
+    <string name="onlyOneEquality">Only one = operator per command is allowed.</string>
+    <string name="operatorExpected">An operator was expected, but an expression was found.</string>
+    <string name="operatorFound">A sub-expression was expected, but an operator was found.</string>
+    <string name="parenthesisMismatch">The numbers of opened and closed parenthesis don\'t match.</string>
+    <string name="readonlyFunc">The "%1$s" function is defined as read-only for %1$s arguments.</string>
+    <string name="readonlyVar">The "%s" variable is defined as read-only.</string>
+    <string name="reservedWord">%s is a reserved word and can\'t be used as symbol name.</string>
+    <string name="rewriteStep">%1$s can be rewritten as %2$s</string>
+    <string name="undefinedFunc">The function "%1$s" is not defined for %2$s arguments.</string>
+    <string name="undefinedVar">The variable "%s" is not defined.</string>
+    <string name="unknownChar">Unrecognized character %s.</string>
 </resources>