## PPG

Object Hierarchy | Related C++ Class: PPGEventContext

### Introduced

v4.0

### Description

Represents an instance of a Property Page. This object can be manipulated within the event handling script code associated with a PPGLayout. (This event handling code is often called "SPDL logic" because in previous versions it could only be specified by putting script code directly in a spdl file.) This object is available to logic code as a global variable called "PPG". (For the purposes of backward compatibility it is also available via the global variable "PSet". It is also for reasons of backward compatibility that this object does not derive from Context and is available as a global variable rather than being passed as an argument to the callback routines).
There are two ways a Property Page can inspect multiple objects. In the first case, where the objects are of different types, there will actually be separate Property Page objects displayed within the same frame. In the second case, where the objects have the same type, multi-edit mode is used and a single instance of the PPG object may actually represent multiple objects. This is why the property PPG.Inspected returns an array rather than a single object.
This object provides shortcuts for direct access to the Parameters of the inspected object. For example, if a Property Page has a parameter named x then "PPG.x.Value = 10" is the VBScript code to change the value. In the case of multi-edit mode, this technique will only modify the first inspected object.
Note: The equivalent object in the C++ API is called PPGEventContext.

### Methods

Close | Refresh |  |

### Properties

CurrentTab | Inspected | InspectedObjects | PPGLayout

### Examples

#### JScript Example

    /*
            This example shows how to build an extremely dynamic Custom Property using
            the PPG object. It appears in two parts:
             * PART ONE writes the implementation to disk, loads it in Softimage, and
               then displays the property editor.
             * PART TWO is the code that implements the custom property
            Not only does the layout change but the actual underlying parameters are
            rebuilt each time the Property Page is shown.
            Once this plugin is installed you can apply an instance of the custom
            property via the Property Menu on the left side of the screen.  Then
            each time you inspect the custom property it will regenerate its UI
            so that there is a check box for each X3DObject parented under the scene
            root.  You can pick which ones to select and then click apply.
            Normally a feature like this would probably be implemented as a custom
            command that pops up a temporary, modal custom property which is deleted
            after the fact.  However for the purpose of this example the custom
            property remains in the scene for use whenever the user wants to change
            selection.
            (This example was implemented by using the Custom Property wizard to
            generate the initial plugin and then editing the code to add the dynamic
            behavior)
    */
    NewScene( null, false );
    // ------------------------------------------------------------
    //
    //              PART ONE: Save Implementation to Disk and Open PPG
    //
    var filename = XSIUtils.BuildPath( Application.InstallationPath(siUserPath),
            "Application", "Plugins", "DynParamDemo.js" );
    // Write the contents of the Implementation functions below to DynParamDemo.js
    var fso = new ActiveXObject( "Scripting.FileSystemObject" );
    var ts = fso.CreateTextFile( filename, true );
    ts.Write( XSILoadPlugin.toString() + "\n\n" );
    ts.Write( DynParamDemo_Define.toString() + "\n\n" );
    ts.Write( DynParamDemo_DefineLayout.toString() + "\n\n" );
    ts.Write( DynParamDemo_OnInit.toString() + "\n\n" );
    ts.Write( DynParamDemo_Apply_OnClicked.toString() );
    ts.Close();
    // Load the plugin
    Application.LoadPlugin( filename );
    // Instantiate the custom property and display its property page
    var oCustomProperty = Application.ActiveSceneRoot.AddProperty( "DynParamDemo" );
    InspectObj( oCustomProperty );
    // ------------------------------------------------------------
    //
    //              PART TWO: PPG Implementation
    //
    function XSILoadPlugin( in_reg )
    {
            in_reg.Author = "Softimage";
            in_reg.Name = "DynParamDemoPlugin";
            in_reg.Major = 1;
            in_reg.Minor = 1;
            in_reg.RegisterProperty( "DynParamDemo" );
            return true;
    }
    function DynParamDemo_Define( io_Context )
    {
            // No parameters are added here because we want the
            // data to be dynamic, see DynParamDemo_OnInit
    }
    function DynParamDemo_DefineLayout( io_Context )
    {
            // Do nothing here because we want a dynamic layout.
            // The work is done inside DynParamDemo_OnInit instead.
    }
    function DynParamDemo_OnInit()
    {
            // This example doesn't make sense in the case
            // of selection of more than one instance of the custom
            // property at a time, so we only look at the first inspected
            var oCustomProperty = PPG.Inspected.Item(0);
            // Remove any existing parameters
            for ( var i=oCustomProperty.Parameters.Count-1; i>=0; i-- ) {
                    oCustomProperty.RemoveParameter( oCustomProperty.Parameters.Item(i) );
            }
            var oLayout = PPG.PPGLayout;
            oLayout.Clear();
            var oSceneChildren = Application.ActiveSceneRoot.Children;
            for ( var j=0; j<oSceneChildren.Count; j++ ) {
                    var oChild = oSceneChildren.Item(j);
                    // Add a boolean parameter to represent this object
                    oCustomProperty.AddParameter2( oChild.Name, siBool, false,
                                    null, null, null, null, 0, siPersistable );
                    // Put this in the layout
                    oLayout.AddItem( oChild.Name, "Select " + oChild.Name );
            }
            oLayout.AddButton( "Apply" );
            PPG.Refresh();
    }
    function DynParamDemo_Apply_OnClicked()
    {
            DeselectAll(); // Call Softimage Command
            var oCustomProperty = PPG.Inspected.Item(0);
            for ( var j=0; j<oCustomProperty.Parameters.Count; j++ ) {
                    var oParam = oCustomProperty.Parameters.Item(j);
                    if ( oParam.Value == true ) {
                            // We used a naming sceme for the parameters that matches the object
                            AddToSelection( oParam.Name );  // Call Softimage Command
                    }
            }
    }

### See Also

PPGLayout.Logic ProjectItem Parameter Context InspectObj Property Host Callbacks