new pdom content, new screen summary node options, string manager val…

…ue functions implemented, link distance display in screen summary to model property, see phetsims/gravity-force-lab#109

js/gravity-force-lab-basics/GravityForceLabBasicsA11yStrings.js

@@ -13,11 +13,17 @@ define( function( require ) {
   var gravityForceLabBasics = require( 'GRAVITY_FORCE_LAB_BASICS/gravityForceLabBasics' );
 
   var GravityForceLabBasicsA11yStrings = {
+    screenSummaryDescription: {
+      value: 'The Play Area has two spheres, a blue sphere labelled Mass 1 and a red sphere labelled Mass 2, and each sphere is held in place by a robot. Arrows representing force starts at center of each sphere and point directly at opposite sphere. Spheres can be moved closer or further from each other, and mass of each sphere can be increased or decreased. In Control Area there are checkboxes and buttons to show force values, show distance between spheres, set spheres to a constant size, and to reset sim.'
+    },
+    basicsSimStateLabel: {
+      value: 'Currently, force on mass 1 by mass 2 is of equal magnitude and pointing directly opposite to the force on mass 2 by mass 1.'
+    },
     massReadoutPattern: {
       value: '{{value}} billion kg'
     },
     massesDistanceApartPattern: {
-      value: 'masses are {{distance}} km apart;'
+      value: 'masses are {{distance}} km apart'
     }
   };
 

js/gravity-force-lab-basics/view/GFLBStringManager.js

@@ -18,18 +18,35 @@ define( require => {
   const forceToPullIndex = new LinearFunction( PULL_FORCE_RANGE.min, PULL_FORCE_RANGE.max, 6, 0, true );
 
   const massesDistanceApartPatternString = GravityForceLabBasicsA11yStrings.massesDistanceApartPattern.value;
-
+  const unitsNewtonsString = require( 'string!INVERSE_SQUARE_LAW_COMMON/units.newtons' );
 
   class GFLBStringManager extends GravityForceLabStringManager {
 
     constructor( model, object1Label, object2Label ) {
-      super( model, object1Label, object2Label, {} );
+      super( model, object1Label, object2Label, {
+        distanceUnits: 'kilometers',
+        centerOffset: 4800,
+        valueUnits: unitsNewtonsString,
+        convertForceValue: value => Util.toFixedNumber( value, 1 ),
+        convertDistanceApart: distance => Util.toFixedNumber( distance / 1e3, 1 ),
+        formatMassValue: mass => `${mass/1e9} billion`, // TODO: convert to proper string usage
+        formatPositionUnitMark: position => {
+          position = Util.toFixedNumber( position / 1e3, 1 );
+          return StringUtils.fillIn( '{{position}} kilometer', { position } );
+        }
+      } );
     }
 
     static getMassesDistanceApart( distance ) {
       return StringUtils.fillIn( massesDistanceApartPatternString, { distance } );
     }
 
+    // TODO: proper string usage
+    getOnlyQualitativeObjectDistanceSummary() {
+      const pattern = '{{mass1}} and {{mass2}} are {{qualitativeDistance}} each other.';
+      return StringUtils.fillIn( pattern, { mass1: this.object1Label, mass2: this.object2Label, qualitativeDistance: this.getQualitativeDistance() } );
+    }
+
     // @override
     getDistanceIndex( distance ) {
       distance /= 1000;

js/gravity-force-lab-basics/view/GravityForceLabBasicsMassNode.js

@@ -48,9 +48,10 @@ define( function( require ) {
       tandem: Tandem.required,
 
       // a11y
+      // TODO: proper string usage
       createAriaValueText: function( formattedValue, previousValue ) {
         formattedValue += 4800;
-        return GFLBStringManager.getPositionMeterMarkText( formattedValue );
+        return GFLBStringManager.getPositionMeterMarkText( `${formattedValue / 1e3} kilometer` );
       }
     }, options );
 

js/gravity-force-lab-basics/view/GravityForceLabBasicsScreenView.js

@@ -17,6 +17,7 @@ define( function( require ) {
   var GFLBStringManager = require( 'GRAVITY_FORCE_LAB_BASICS/gravity-force-lab-basics/view/GFLBStringManager' );
   var GravityForceLabA11yStrings = require( 'GRAVITY_FORCE_LAB/gravity-force-lab/GravityForceLabA11yStrings' );
   var gravityForceLabBasics = require( 'GRAVITY_FORCE_LAB_BASICS/gravityForceLabBasics' );
+  var GravityForceLabBasicsA11yStrings = require( 'GRAVITY_FORCE_LAB_BASICS/gravity-force-lab-basics/GravityForceLabBasicsA11yStrings' );
   var GravityForceLabBasicsConstants = require( 'GRAVITY_FORCE_LAB_BASICS/gravity-force-lab-basics/GravityForceLabBasicsConstants' );
   var GravityForceLabBasicsMassNode = require( 'GRAVITY_FORCE_LAB_BASICS/gravity-force-lab-basics/view/GravityForceLabBasicsMassNode' );
   var GravityForceLabScreenSummaryNode = require( 'GRAVITY_FORCE_LAB/gravity-force-lab/view/GravityForceLabScreenSummaryNode' );
@@ -62,6 +63,8 @@ define( function( require ) {
   var spherePositionsString = ISLCA11yStrings.spherePositions.value;
   var spherePositionHelpTextString = ISLCA11yStrings.spherePositionHelpText.value;
   var massControlsLabelString = GravityForceLabA11yStrings.massControlsLabel.value;
+  var screenSummaryDescriptionString = GravityForceLabBasicsA11yStrings.screenSummaryDescription.value;
+  var basicsSimStateLabelString = GravityForceLabBasicsA11yStrings.basicsSimStateLabel.value;
 
   /**
    * @param {GravityForceLabBasicsModel} model
@@ -75,7 +78,12 @@ define( function( require ) {
     } );
 
     var stringManager = new GFLBStringManager( model, mass1LabelString, mass2LabelString );
-    var summaryNode = new GravityForceLabScreenSummaryNode( model, stringManager );
+    var summaryNode = new GravityForceLabScreenSummaryNode( model, stringManager, {
+      descriptionContent: screenSummaryDescriptionString,
+      summaryOptions: {
+        simStateLabel: basicsSimStateLabelString
+      }
+    } );
     var playAreaNode = new PlayAreaNode();
     var controlAreaNode = new ControlAreaNode();
     this.screenSummaryNode.addChild( summaryNode );
@@ -200,6 +208,14 @@ define( function( require ) {
     } );
     controlAreaNode.addChild( resetAllButton );
 
+    // link summary content to distance property
+    model.showDistanceProperty.link( function( showDistance ) {
+      var content = showDistance ?
+                    stringManager.getObjectDistanceSummary() :
+                    stringManager.getOnlyQualitativeObjectDistanceSummary();
+      summaryNode.objectDistanceSummaryItem.innerContent = content;
+    } );
+
     // layout the view elements
     parameterControlPanel.right = this.layoutBounds.width - 15;
     parameterControlPanel.bottom = MASS_CONTROLS_Y_POSITION;