## PPGLayout.AddButton

### Introduced

v4.0

### Description

Adds a button to a layout. Unlike other controls a button doesn't have to be associated with any particular Parameter on the inspected object. Instead it basically serves the purpose of executing some script code when pressed.
By default, the width of the button is automatically determined based on the text of the Label. However this can be overridden with the siUICX attribute. (See PPGItem.SetAttribute)

### C# Syntax

    PPGItem PPGLayout.AddButton( String in_ScriptName, String in_opt_Label );

### Scripting Syntax

    oReturn = PPGLayout.AddButton( ScriptName, [Label] );

### Return Value

PPGItem

### Parameters

Parameter | Type | Description
--- | --- | ---
ScriptName | String | A unique name for the button, which should not contain any space characters. This name is used to determine the logic subroutine to call when the button is pressed.
Label | String | Label of the button. If not specified then the ScriptName is displayed.

### Examples

#### 1. JScript Example

    /*
            This example creates a custom property with a single parameter called "Data" and a button.
            Each time you click the button the value is randomized
    */
    var oPSet = ActiveSceneRoot.AddProperty( "CustomProperty", false, "ButtonExample" ) ;
    oPSet.AddParameter3( "Data", siDouble, 0, 0, 1 ) ;
    var oLayout = oPSet.PPGLayout
    oLayout.AddRow() ;
    oLayout.AddItem( "Data" ) ;
    oLayout.AddButton( "Randomize" ) ;
    oLayout.EndRow() ;
    oLayout.Logic = Randomize_OnClicked.toString() ;
    oLayout.Language = "JScript" ;
    InspectObj( oPSet ) ;
    function Randomize_OnClicked()
    {
            PPG.Data.Value = Math.random() ;
    }

#### 2. VBScript Example

    '
    ' This example creates a custom property with a single parameter called "Data" and a button.
    ' Each time you click the button the value is randomized
    '
    set oPSet = ActiveSceneRoot.AddProperty( "CustomProperty", false, "ButtonExample" )
    oPSet.AddParameter3 "Data", siDouble, 0, 0, 1
    set oLayout = oPSet.PPGLayout
    oLayout.AddRow
    oLayout.AddItem "Data"
    oLayout.AddButton "Randomize"
    oLayout.EndRow
    'Store a little VBScript code to react to the button press.
    'If this code was more sophisticated we could read it out
    'of a file
    oLayout.Logic = "sub Randomize_OnClicked"   & vbCrlf & "   PPG.Data.Value = Rnd" & vbCrlf & "end sub"
    oLayout.Language = "VBScript" 'Optional because this is the default
    InspectObj oPSet

#### 3. JScript Example

    /*
            Example showing how to disable a button
            Often certain buttons should be disabled if they don't apply in the current context.
            In this case a button is only enabled if there is text entered in a edit box.  The
            button gets enabled and disabled by the SomeText_OnChanged() callback.  This callback
            is not called as characters are actually entered in the text box, but as soon as that
            edit box loses focus (for example if the tab key is pressed )
    */
    var oPSet = ActiveSceneRoot.AddProperty( "CustomProperty", false, "ButtonExample" ) ;
    oPSet.AddParameter3( "SomeText", siString ) ;
    var oLayout = oPSet.PPGLayout
    oLayout.AddRow() ;
    oLayout.AddItem( "SomeText" ) ;
    var oItem = oLayout.AddButton( "ClickMe", "Click Me" ) ;
    // Set a PPGItem attribute to disable the control
    // (because initially there is no text inside SomeText)
    oItem.SetAttribute( "buttondisable", true ) ;
    oLayout.EndRow() ;
    oLayout.Logic = SomeText_OnChanged.toString() + ClickMe_OnClicked.toString() ;
    oLayout.Language = "JScript" ;
    InspectObj( oPSet ) ;
    // PPG Logic that is provided to the PPG
    function SomeText_OnChanged()
    {
            // Button will be disabled until some text is entered
            bDisableButton = ( PPG.SomeText.Value.length == 0 ) ;
            // Get the layout
            oPPGLayout = PPG.PPGLayout ;
            // Lookup the PPGItem associated with the button
            oPPGItem = oPPGLayout.Item( "ClickMe" ) ;
            bAlreadyDisabled = oPPGItem.GetAttribute( "buttondisable" ) ;
            if ( bDisableButton != bAlreadyDisabled )
            {
                    oPPGItem.SetAttribute( "buttondisable", bDisableButton ) ;
                    // We only call refresh if we determine the state has
                    // actually changed
                    PPG.Refresh() ;
            }
    }
    function ClickMe_OnClicked()
    {
            // Will never be called if the SomeText is empty
            XSIUIToolkit.MsgBox( "Value of text is " +  PPG.SomeText.Value ) ;
    }

### See Also

PPGLayout.AddItem PPGItem.Label PPGItem.Name PPG PPGLayout.Logic