Daily Archives: February 12, 2013

HMG Message functions

Posted on by vivaclipper

As noticed in Hello Word – 3 sample, HMG has a lot of message functions with name prefixed by “Msg”:

MsgBox() :

Shows a Message Box

Syntax: MsgBox(<cMessage>,[<cTitle>]) –> Nil

Example : MsgBox( “This a simple message”, “MsgBox Example” )

MsgExclamation() :

Shows a message box with an exclamation icon and a special sound.

Syntax: MsgExclamation(<cMessage>,[<cTitle>]) –> Nil

Example : MsgExclamation( “Wrong selection !”, “MsgExclamation Example” )

MsgInfo() :

Shows a message box with an information icon and a special sound.

Syntax: MsgInfo (<cMessage>,[<cTitle>]) –> Nil

Example : MsgInfo( “For your information”, “MsgInfo Example” )

MsgStop() :

Shows a message box with an stop icon and a special sound.

Syntax: MsgStop(<cMessage>,[<cTitle>]) –> Nil

Example : MsgStop( “End of file reached”, “MsgStop Example” )

MsgOkCancel() :

Shows a message box with [Ok] and [Cancel] buttons

Syntax: MsgOkCancel(<cMessage>,[<cTitle>]) –> lResponse

Example : MsgOkCancel( “Are your to exit ?”, “MsgOkCancel Example” )

MsgRetryCancel() :

Shows a message box with [Retry] and [Cancel] buttons

Syntax: MsgRetryCancel(<cMessage>,[<cTitle>]) –> lResponse

Example: MsgRetryCancel( “File open error !”, “MsgRetryCancel Example” )

MsgYesNo() :

Shows a message box with [Yes] and [No] buttons

Syntax: MsgYesNo( <cMessage> , <cTitle> ) –> lResponse

Example: MsgYesNo( “Are you sure to delete file ?”, “Confirm Delete” )

Like MsgBox(), all message functions accept parameters as a string constant representing the message itself. All message functions also have a second parameter, again a string constant representing the title of message box.

As noticed in syntax, the first four message functions returns NIL, and the last three returns a logical value.

<lResponse> is .T. when selected first option; Ok, Retry and Yes.

Try and observe results.

Hints :

– As a rule, every HMG project must have one and only one “Main” window. This message functions are exception of this rule. If you have only message function(s) you can build a program without main window.

– For multiple lines message body you may use CRLF. CRLF is a predefined constant in HMG. If required you may define it:

CRLF := HB_OsNewLine()

Example :

MsgBox( "This is a" + CRLF + "multiple line" + CRLF + ;
        "message", CRLF + "Multi-Line" )

– Since message function accept only “C” ( Character ) type arguments as <cMessage> and <cTitle>; for messaging other that ‘C’ type arguments, you may use appropriate function to convert  to character type. See below for an example.

Example :

/*
 HMG Message functions
*/
#include <hmg.ch>

dToday := DATE()
lMaried := .T.
nSalary := 123.456

PROCEDURE Main()
  SET DATE GERM
  SET CENT ON

  dToday := DATE()
  lMaried := .T.
  nSalary := 123.456
  DEFINE WINDOW frmMsgFuncs ;
     AT 0,0 ;
     WIDTH 400 ;
     HEIGHT 200 ;
     TITLE 'Message Functions' ;
     MAIN
     DEFINE MAIN MENU

        DEFINE POPUP '&Test'

          ITEM 'Msg&Box' ACTION ;
                MsgBox( "This a simple message", "MsgBox Example" ) 
          ITEM 'Msg&Exclamation' ACTION ;
                MsgExclamation( "Wrong selection !", "MsgExclamation Example" ) 
          ITEM 'Msg&Info' ACTION ;
                MsgInfo( "For your information", "MsgInfo Example" )
          ITEM 'Msg&Stop' ACTION ;
                MsgStop( "End of file reached", "MsgStop Example" ) 
          ITEM 'Msg&OkCancel' ACTION ;
                MsgOkCancel( "Are your to exit ?", "MsgOkCancel Example" ) 
          ITEM 'Msg&RetryCancel' ACTION ;
                MsgRetryCancel( "File open error !", "MsgRetryCancel Example" )
          ITEM 'Msg&YesNo' ACTION ;
                MsgYesNo( "Are you sure to delete file ?", "Confirm Delete" )
 ITEM 'Multiple &Line' ACTION ; 
       MsgBox( "This is a" + CRLF + "multiple line" + CRLF + ;
               "message", CRLF + "Multi-Line" ) 
 ITEM 'Non-Character' ACTION ; 
       MsgBox( "Today : "   + DTOC( dToday ) + CRLF +;
               "Married : " + IF( lMaried, "Yes", "No" ) + CRLF +;
               "Salary : "   + LTRIM( STR( nSalary ) ) ,;
               "Non-Char" )
 SEPARATOR

 ITEM "E&xit" ACTION ThisWindow.Release

END POPUP // File

END MENU // Main()

END WINDOW // Main

CENTER WINDOW frmMsgFuncs

ACTIVATE WINDOW frmMsgFuncs

RETURN // Main()
*-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._-._.-._.-._.-._.-._.-._.-._.-

Hello World – 3

Posted on by vivaclipper

Don’t worry ! This is the last; and important.

Extract DEFINE LABEL – END LABEL structure or @ …,… LABEL command ( which one is currently exist) and then instead of them place this line :

MsgBox( "Hello World !" )

In HMG, there are a lot of message functions, with name prefixed by “Msg“; for details please look at HMG Message Functions page.

After building and running, try a more important feature: reduce your program to these minimum size:

#include <hmg.ch>
PROCEDURE Main
   MsgBox( "Hello World !" )

RETURN // Main()

In fact, as a rule, every HMG project must have one and only one “Main” window. This message functions are exception of this rule. If you have only message function(s) you can build a program without main window.

Hello World – 2

Posted on by vivaclipper

In the our first example in first Quick Start page, we wrote the “Hello World” clause on the title bar. Now, let’s put it on the form.

Build a new project with “HelloWorld2” name, copy HelloWord.prg to HelloWorld2.prg and change it as below:

#include <hmg.ch>
PROCEDURE Main()
   DEFINE WINDOW frmHWLabel ;
      AT 0,0 ;
      WIDTH 400 ;
      HEIGHT 200 ;
      TITLE 'Hello World-2' ;
      MAIN 

      DEFINE LABEL lblHello
         ROW 75
         COL 125
         VALUE "Hello World !"
         FONTNAME "Lucida"
         FONTSIZE 16
      END LABEL

    END WINDOW 

    ACTIVATE WINDOW frmHWLabel

RETURN // Main()

DEFINE LABEL and END LABEL statements are for “Label” definition structure for the a window ( in this example Windows named as “frmHWLabel ” ). Label itself must have a name (“lblHello” in this example), and this name must be unique, such as a variable name. Beginning these names with a descriptive prefix ( “lbl” in the example) is a good programming practice.

Between DEFINE – END statements there are main properties of this label. Row, col numbers ( in pixels of course),value (for labels, value is a string constant to write in the your form/window) and font properties (NAME and SIZE)

Almost every GUI control definitions HMG have two syntax : With DEFINE and END structure and with @ command.Thus in the above example instead of DEFINE LABEL and END LABEL structure, you can use alternate @ syntax :

@ 75, 125 LABEL lblHello ;
          VALUE "Hello World !" ;
          FONT "Lucida" ; 
          SIZE 16

A last note for this example : place

CENTER WINDOW frmHWLabel

statement END WINDOW statement and notice that how much HMG is powerful.

HelloWordLabel