Hi,
My form contains scroll window with two label's to display error and status message and two buttons i.e, "Generate" and "Cancel".
Whenever I click on "Generate" buttons I have to get a status message saying "Kit generate process is in Progress" and when the process is complete display a message in same status label saying "Kit Is Created Successfully." and return from the event. This whole process is happening in a single event. The issue is application is giving the last message in the status label before the return from the event . No intermediate messages are being displayed.
Code Snippet:
Below is the code snippet for "Generate" Buttons.
//The below method is to register the application callbacks for "Cancel" and "Generate" Button Form Elements.
Logical CreateDbKit::register_application_callbacks( )
{
bool status = dispatch.map( fe_Cancel, &CreateDbKit::KitCancel )
&& dispatch.map( fe_Generate, &CreateDbKit::Generate );
return status;
}
//This method is called when the user clicks on the Generate button.
Logical CreateDbKit::Generate( const FormEvent& event )
{
bool status = true;
_errormsg = "Kit Is Created Successfully.";
message( format_msg( KitInProgress ) ); -----------------------------------> Not being printed In the status label
message( format_msg( KitGenerated, _errormsg.c_str( ) ) ); ----------> Only final message is being printed in the status label
unlock();
return status;
}
End Code Snippet:
Below are the lists of approaches tried so far. But no luck.
1) Adding sleep(10) in between two message like below.
message( format_msg( KitInProgress ) ); -----------------------------------> Not being printed In the status label
sleep(10);
message( format_msg( KitGenerated, _errormsg.c_str( ) ) ); ----------> Only final message is being printed in the status label
2) Calling extra "message(...)" function call like below.
message( format_msg( KitInProgress ) ); ------------------------------------> Not being printed In the status label
sleep(10);
_errormsg = "Kit Created Failed.";
message( format_msg( KitGenFailed, _errormsg.c_str( ) ) ); ----------> Still not being printed In the status label
sleep(10);
message( format_msg( KitGenerated, _errormsg.c_str( ) ) ); ----------> Only final message is being printed in the status label
3) If I call This function i.e "graph_db->process_pending_events( );" in between every messages then it works for 2-3 times then only.like Below.
message( format_msg( KitInProgress ) ); ------------------------------------> printed In the status label only 2-3 times then only.
graph_db->process_pending_events( );
_errormsg = "Kit Created Failed.";
message( format_msg( KitGenFailed, _errormsg.c_str( ) ) ); ----------> Still not being printed In the status label
graph_db->process_pending_events( );
message( format_msg( KitGenerated, _errormsg.c_str( ) ) ); ----------> Only final message is being printed in the status label
Definition of this function is below:
inline void Graphic_DB::process_pending_events( )
{
XtInputMask input_mask;
while ( (input_mask = XtAppPending( Graphic_DB::app_context )) )
{
XtAppProcessEvent( Graphic_DB::app_context, input_mask );
}
}
Please Please Advise me, as I am very new to this Motif world.
Please find below a sample demonstrating how to update widgets during long-time operations. This is just one of possible implementations assumed you use only one thread.
#include <stdio.h> #include <stdlib.h> #include <Xm/XmAll.h> XtAppContext app_context; void ButtonCallback(Widget wd, XtPointer client_data, XtPointer call_data) { static int ExecutionControl=0; // Multiple callback entering control if (ExecutionControl > 0) { printf("Multiple entering to callback function is denied\n"); return; } ExecutionControl++; // Initial message about long-time operation XmString xmsg = XmStringCreateLocalized("Executing long time operation ..."); XtVaSetValues(wd, XmNlabelString, xmsg,NULL); XmStringFree(xmsg); int i=0; char Str[30]; const int CountItems=10; // Simulation of long-time processing operation for (i=0; i< CountItems; i++) { // Processing Motif event loop while (XtAppPending(app_context)) { XEvent event; XtAppNextEvent(app_context, &event); XtDispatchEvent(&event); } // simulation processing operation sleep(1); // Output of intermediate results of operation sprintf(Str, "Processed %d %%", 100*(i+1)/CountItems); xmsg = XmStringCreateLocalized(Str); XtVaSetValues(wd, XmNlabelString, xmsg); XmStringFree(xmsg); } sleep(1); // Operation is finished! xmsg = XmStringCreateLocalized("Processing finished!"); XtVaSetValues(wd, XmNlabelString, xmsg); XmStringFree(xmsg); ExecutionControl--; } int main(int argc, char *argv[]) { Widget Label, Button, rc1; Widget toplevel, MainWindow; Arg args[10]; Cardinal ac; XtSetLanguageProc(NULL, NULL, NULL); toplevel = XtVaOpenApplication(&app_context, "SampleApp_shell", NULL, 0, &argc, argv, NULL,sessionShellWidgetClass,NULL); ac=0; MainWindow = XmCreateMainWindow(toplevel, "SampleApp_main_window", args, ac); // RowColumn creating ac=0; XtSetArg(args[ac], XmNrowColumnType, XmWORK_AREA); ac++; XtSetArg(args[ac], XmNorientation, XmVERTICAL); ac++; rc1 = XmCreateRowColumn(MainWindow, "rc1", args , ac); XtVaSetValues(MainWindow, XmNworkWindow, rc1, NULL); // Label creating ac=0; XmString xmstr = XmStringCreateLocalized("Press button:"); Label = XmCreateLabel(rc1, "label", args, ac); XtVaSetValues(Label, XmNlabelType, XmSTRING, XmNlabelString, xmstr, NULL); XtManageChild(Label); XmStringFree(xmstr); // Button creating ac=0; xmstr = XmStringCreateLocalized("Execute long operation... "); Button = XmCreatePushButton(rc1, "execute_button", args, ac); XtVaSetValues(Button, XmNlabelString, xmstr, NULL); XtManageChild(Button); XmStringFree(xmstr); // Calback for Add Host button XtAddCallback(Button, XmNactivateCallback, ButtonCallback, (XtPointer)NULL); XtManageChild(rc1); XtManageChild(MainWindow); XtRealizeWidget(toplevel); XtAppMainLoop(app_context); return 0; }