Display help information identified by a topic path
int PtHelpTopic( char *topic );
ph
PtHelpTopic() tells the Helpviewer to display the help text located by the given topic path.
PtHelpTopic() spawns the Helpviewer if it isn't running, or sends a message to the Helpviewer if it is. Using this function, a Photon application can respond to a help request from the user by telling the Helpviewer to display the relevant help information.
If the topic path is relative (i.e. it doesn't start with a /), it's appended to the root topic path specified in an earlier call to PtHelpTopicRoot().
0 on success, or -1 if the Helpviewer couldn't be found or spawned.
PtHelpTopic() returns immediately, before the help topic has been displayed. |
The following example shows a fragment from a hypothetical application built using PhAB. This application first sets up a topic root for all help requests; it then displays help for a particular part of the application in response to a callback (which could be attached to a hotkey, for example).
#include <Pt.h> int main( void ) { … PtHelpTopicRoot( "/Photon microGUI/Programmer's Guide/Introduction" ); … } int HelpCallback( PtWidget_t * widget, ApInfo_t * apinfo, PtCallbackInfo_t * cbinfo ) { … if( widget == ABW_Concepts ) PtHelpTopic( "Widget concepts" ); … return( Pt_CONTINUE ); }
Photon
Safety: | |
---|---|
Interrupt handler | No |
Signal handler | No |
Thread | No |
PtHelpQuit(), PtHelpSearch(), PtHelpTopicRoot(), PtHelpTopicTree(), PtHelpUrl(), PtHelpUrlRoot()
Context-Sensitive Help chapter of the Photon Programmer's Guide
helpviewer in the QNX Neutrino Utilities Reference.