<doc>
	<legacy_id>2284</legacy_id>
	<name>openBackground</name>
	<type>message</type>

	<syntax>
		<example>openBackground <i>backgroundID</i></example>
	</syntax>

	<synonyms>
	</synonyms>

	<summary>Sent to all background groups when a card they are placed on is opened.</summary>

	<examples>
<example><p>on openBackground theBackgroundID</p><p>  -- update content of group</p><p>end openBackground</p></example>
<example><p>on openBackground theBackgroundID</p><p>   if the short name of this card is "highscores" then</p><p>      show button "play again"</p><p>   end if</p><p>end openBackground</p></example>
	</examples>

	<history>
		<introduced version="1.0">Added.</introduced>
		<deprecated version=""></deprecated>
		<removed version=""></removed>
		
		<experimental version=""></experimental>
		<nonexperimental version=""></nonexperimental>
	</history>

	<objects>
		<card/>
	</objects>

	<platforms>
		<mac/>
		<windows/>
		<linux/>
		<ios/>
		<android/>
	</platforms>

	<classes>
		<desktop/>
		<server/>
		<web/>
		<mobile/>
	</classes>

	<security>
	</security>


	<classification>
		<category>Navigation &amp; Hypertext</category>
	</classification>

	<references>
		<property tag="backgroundBehavior">backgroundBehavior Property</property>
		<message tag="preOpenBackground">preOpenBackground Message</message>
		<message tag="startup">startup Message</message>
		<message tag="closeBackground">closeBackground Message</message>
		<message tag="newBackground">newBackground Message</message>
		<message tag="openCard">openCard Message</message>
		<message tag="openStack">openStack Message</message>
	</references>

	<description>
	<overview>Handle the <b>openBackground</b> message to change a group's objects, or perform other updates, when a card with the group on it is opened.</overview>

		<parameters>
<parameter>
<name>backgroundID</name>
<description>The ID number of the background being opened.</description>
</parameter>		</parameters>

	<value></value>
	<comments>The <b>openBackground</b> <keyword tag="message box">message</keyword> is sent to background groups, if there is more than one <command tag="group">group</command> on the <keyword tag="card">card</keyword>, the <b>openBackground</b> <keyword tag="message box">message</keyword> is sent to each one.<p></p><p>The <b>openBackground</b> <keyword tag="message box">message</keyword> is sent after the destination <keyword tag="card">card</keyword> is visible. To make changes that take effect before the <keyword tag="card">card</keyword> becomes visible on the screen, use the <message tag="preOpenBackground">preOpenBackground</message> <keyword tag="message box">message</keyword> instead.</p><p></p><p>The actual navigation is not triggered by the <b>openBackground</b> <keyword tag="message box">message</keyword>, so <glossary tag="trap">trapping</glossary> the <keyword tag="message box">message</keyword> and not allowing it to <control_st tag="pass">pass</control_st> does not prevent the <keyword tag="card">card</keyword> with the <command tag="group">group</command> from opening.</p><p></p><p><note> A group is only considered a background group if its backgroundBehavior property is set to true.</note></comments>
	</description>
</doc>