formatted value text for #71

js/ohms-law/OhmsLawA11yStrings.js

@@ -0,0 +1,33 @@
+// Copyright 2017, University of Colorado Boulder
+
+/**
+ * Single location of all accessibility strings.  These strings are not meant to be translatable yet.  Rosetta needs
+ * some work to provide translators with context for these strings, and we want to receive some community feedback
+ * before these strings are submitted for translation.
+ *
+ * @author Jesse Greenberg
+ */
+define( function( require ) {
+  'use strict';
+
+  var ohmsLaw = require( 'OHMS_LAW/ohmsLaw' );
+
+  var OhmsLawA11yStrings = {
+    resistanceUnitsPatternString: '{{value}} Ohms',
+    voltageUnitsPatternString: '{{value}} Volts'
+
+  };
+
+  if ( phet.chipper.queryParameters.stringTest === 'xss' ) {
+    for ( var key in OhmsLawA11yStrings ) {
+      OhmsLawA11yStrings[ key ] += '<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVQIW2NkYGD4DwABCQEBtxmN7wAAAABJRU5ErkJggg==" onload="window.location.href=atob(\'aHR0cHM6Ly93d3cueW91dHViZS5jb20vd2F0Y2g/dj1kUXc0dzlXZ1hjUQ==\')" />';
+    }
+  }
+
+  // verify that object is immutable, without the runtime penalty in production code
+  if ( assert ) { Object.freeze( OhmsLawA11yStrings ); }
+
+  ohmsLaw.register( 'OhmsLawA11yStrings', OhmsLawA11yStrings );
+
+  return OhmsLawA11yStrings;
+} );

js/ohms-law/view/ControlPanel.js

@@ -15,6 +15,7 @@ define( function( require ) {
   var OhmsLawConstants = require( 'OHMS_LAW/ohms-law/OhmsLawConstants' );
   var Panel = require( 'SUN/Panel' );
   var SliderUnit = require( 'OHMS_LAW/ohms-law/view/SliderUnit' );
+  var OhmsLawA11yStrings = require( 'OHMS_LAW/ohms-law/OhmsLawA11yStrings' );
 
   // strings
   var resistanceUnitsString = require( 'string!OHMS_LAW/resistanceUnits' );
@@ -24,6 +25,11 @@ define( function( require ) {
   var voltageSymbolString = require( 'string!OHMS_LAW/voltageSymbol' );
   var voltageString = require( 'string!OHMS_LAW/voltage' );
 
+  // a11y strings - these strings are not meant to be translatable until the translation utility
+  // can provide translators with context
+  var resistanceUnitsPatternString = OhmsLawA11yStrings.resistanceUnitsPatternString;
+  var voltageUnitsPatternString = OhmsLawA11yStrings.voltageUnitsPatternString;
+
   /**
    * @param {Property.<number>} voltageProperty
    * @param {Property.<number>} resistanceProperty
@@ -51,7 +57,9 @@ define( function( require ) {
       tandem.createTandem( 'voltageSlider' ),
       {
         keyboardStep: 0.5, // volts
-        shiftKeyboardStep: 0.1 // volts
+        shiftKeyboardStep: 0.1, // volts
+        accessibleDecimalPlaces: 1,
+        accessibleValuePattern: voltageUnitsPatternString
       } );
 
     // Create the resistance slider with readout and labels
@@ -63,9 +71,9 @@ define( function( require ) {
       resistanceUnitsString,
       tandem.createTandem( 'resistanceSlider' ),
       {
-        numberDecimalPlaces: 0,
         keyboardStep: 20, // ohms
-        shiftKeyboardStep: 1 // ohms
+        shiftKeyboardStep: 1, // ohms
+        accessibleValuePattern: resistanceUnitsPatternString
       } );
 
     // Use a content node so that the Panel can surround it fully

js/ohms-law/view/SliderUnit.js

@@ -36,9 +36,10 @@ define( function( require ) {
   function SliderUnit( property, range, symbolString, nameString, unitString, tandem, options ) {
 
     options = _.extend( {
-      numberDecimalPlaces: 1,
+      accessibleDecimalPlaces: 0,
       keyboardStep: 1,
-      shiftKeyboardStep: 0.1
+      shiftKeyboardStep: 0.1,
+      accessibleValuePattern: '{{value}}' // string pattern used for formating the value read by the screen reader
     }, options );
 
     Node.call( this );
@@ -52,7 +53,8 @@ define( function( require ) {
       trackSize: new Dimension2( OhmsLawConstants.SLIDER_HEIGHT, 4 ),
       keyboardStep: options.keyboardStep,
       shiftKeyboardStep: options.shiftKeyboardStep,
-      numberDecimalPlaces: options.numberDecimalPlaces,
+      accessibleDecimalPlaces: options.accessibleDecimalPlaces,
+      accessibleValuePattern: options.accessibleValuePattern, 
       tandem: tandem.createTandem( 'slider' )
     } );
 
@@ -76,7 +78,7 @@ define( function( require ) {
       children: [ symbolText, nameText ]
     } );
 
-    var valueText = new Text( Util.toFixed( range.max, options.numberDecimalPlaces ), {
+    var valueText = new Text( Util.toFixed( range.max, options.accessibleDecimalPlaces ), {
       font: OhmsLawConstants.READOUT_FONT,
       fill: OhmsLawConstants.BLACK_COLOR,
       tandem: tandem.createTandem( 'valueText' )
@@ -112,7 +114,7 @@ define( function( require ) {
 
     // Update value of the readout. Present for the lifetime of the simulation; no need to unlink.
     property.link( function( value ) {
-      valueText.text = Util.toFixed( value, options.numberDecimalPlaces );
+      valueText.text = Util.toFixed( value, options.accessibleDecimalPlaces );
       readout.centerX = readoutBackground.selfBounds.centerX;
     } );