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diff --git a/specs/appF.xml b/specs/appF.xml new file mode 100644 index 0000000..49f054b --- /dev/null +++ b/specs/appF.xml @@ -0,0 +1,103 @@ +<appendix id='Resource_Configuration_Management'> +<title>Resource Configuration Management</title> +<para> +Setting and changing resources in X applications can be difficult for +both the application programmer and the end user. <emphasis role='strong'>Resource +Configuration Management (RCM)</emphasis> addresses this problem by changing +the <function>X Intrinsics</function> to immediately modify a resource for a +specified widget and each child widget in the hierarchy. +In this context, immediate means: no sourcing of a resource +file is required; the application does not need to be restarted for the +new resource values to take effect; and the change +occurs immediately. +</para> + +<para> +The main difference between <function>RCM</function> and the <function>Editres</function> +protocol is that the <function>RCM</function> +customizing hooks reside in the <function>Intrinsics</function> and thus are linked with +other toolkits such as Motif and the Athena widgets. However, the +<function>EditRes</function> protocol requires the application to link with the +<function>EditRes</function> +routines in the Xmu library and Xmu is not used by all applications that +use Motif. Also, the <function>EditRes</function> protocol uses ClientMessage, +whereas the +<function>RCM</function> <function>Intrinsics</function> hooks use <function>PropertyNotify</function> events. +</para> + +<para> +X Properties and the <function>PropertyNotify</function> events are used +to implement <function>RCM</function> and +allow on-the-fly resource customization. When the X Toolkit is +initialized, two atoms are interned with the strings +<emphasis remap='I'>Custom Init</emphasis> and +<emphasis remap='I'>Custom Data</emphasis>. Both +<function>_XtCreatePopupShell</function> +and +<function>_XtAppCreateShell</function> +register a <function>PropertyNotify</function> event handler to handle these properties. +</para> + +<para> +A customization tool uses the <emphasis remap='I'>Custom Init</emphasis> property to <emphasis remap='I'>ping</emphasis> an +application to get the application's toplevel window. When the +application's property notify event handler is invoked, the handler +deletes the property. No data is transferred in this property. +</para> + +<para> +A customization tool uses the <emphasis remap='I'>Custom Data</emphasis> property to tell an +application that it should change a resource's value. The data in +the property contains the length of the resource name (the number +of bytes in the resource name), the resource name and the new +value for the resource. This property's type is <function>XA_STRING</function> and +the format of the string is: +</para> +<orderedlist> + <listitem> + <para> +The length of the resource name (the number of bytes in +the resource name) + </para> + </listitem> + <listitem> + <para> +One space character + </para> + </listitem> + <listitem> + <para> +The resource name + </para> + </listitem> + <listitem> + <para> +One space character + </para> + </listitem> + <listitem> + <para> +The resource value + </para> + </listitem> +</orderedlist> +<para> +When setting the application's resource, the event handler calls +functions to walk the application's widget tree, determining which +widgets are affected by the resource string, and then applying the value +with +<xref linkend='XtSetValues' xrefstyle='select: title'/>. +As the widget tree is recursively descended, at +each level in the widget tree a resource part is tested for a match. +When the entire resource string has been matched, the value is applied +to the widget or widgets. +</para> + +<para> +Before a value is set on a widget, it is first determined if the last +part of the resource is a valid resource for that widget. It must also +add the resource to the application's resource database and then query +it using specific resource strings that is builds from the widget +information. +</para> +</appendix> |