ReadVar()

READVAR()

Return variable name of current GET or MENU

Syntax

      READVAR( [<cVarName>] ) --> cOldVarName

Arguments

<cVarName> is a new variable name to set.

Returns

READVAR() return the old variable name. If no variable previously was set, READVAR() return “”.

Description

READVAR() is set inside a READ or MENU TO command to hold the uppercase name of the GET / MENU TO variable, and re-set back to old value when those commands finished. You should not normally set a variable name but rather use it to retrieve the name of a GET variable when executing a VALID or WHEN clause, or during SET KEY execution and you are inside a READ or MENU TO.

Examples

      // display a menu, press F1 to view the MENU TO variable name
      CLS
      @ 1, 10 PROMPT "blood sucking insect that infect beds   "
      @ 2, 10 PROMPT "germ; virus infection                   "
      @ 3, 10 PROMPT "defect; snag; (source of) malfunctioning"
      @ 4, 10 PROMPT "small hidden microphone                 "
      @ 6, 10 SAY "(Press F1 for a hint)"
      SET KEY 28 TO ShowVar
      MENU TO What_Is_Bug

      PROCEDURE ShowVar
         Alert( ReadVar() )     // WHAT_IS_BUG in red ALERT() box

Compliance

READVAR() works exactly like CA-Cl*pper’s READKEY().

Note however, that the <cVarName> parameter is not documented and used internally by CA-Cl*pper.

Platforms

All

Files

Library is rtl

Seealso

@…GET, @…PROMPT, MENU TO, READ, SET KEY, __AtPrompt(), __MenuTo()

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MENU TO

MENU TO

Invoked a menu defined by set of @…PROMPT

Syntax

      MENU TO <cVariable>

Arguments

<cVariable> is a character string that contain the name of the variable to hold the menu choices, if this variable does not exist a PRIVATE variable with the name <cVariable> would be created to hold the result.

Description

Menu To() invoked the menu define by previous __AtPrompt() call and display a highlight bar that the user can move to select an option from the menu. If <cVariable> does not exist or not visible, a PRIVATE variable named <cVariable> is created and hold the current menu selection. If there is a variable named <cVariable>, its value is used to select the first highlighted item.

Menu prompts and messages are displayed in current Standard color, highlighted bar is displayed using current Enhanced color.

Pressing the arrow keys move the highlighted bar. When a menu item is highlighted the message associated with it is displayed on the line specified with SET MESSAGE. If SET WRAP is ON and the user press UP arrow while on the first selection the last menu item is highlighted, if the user press Down arrow while on the last item, the first item is highlighted.

Following are active keys that handled by Menu To:

       key            Meaning
       -------------- ---------------------------------
       Up             Move to previous item
       Down           Move to next item
       Left           Move to previous item
       Right          Move to next item
       Home           Move to the first item
       End            Move to the last item
       Page-Up        Select menu item, return position
       Page-Down      Select menu item, return position
       Enter          Select menu item, return position
       Esc            Abort selection, return 0
       First letter   Select next menu with the same first letter,
                      return this item position.

Upon exit the cursor is placed at MaxRow()-1, 0 Menu To can be nested without loosing the previous prompts.

MENU TO command is preprocessed into __MenuTo() function during compile time.

Examples

      // display menu item on each screen corner and let user select one
      CLS
      SET MESSAGE TO MaxRow() / 2 CENTER
      SET WRAP ON
      @ 0           , 0             PROMPT "1. Upper left"   MESSAGE " One "
      @ 0           , MaxCol() - 16 PROMPT "2. Upper right"  MESSAGE " Two "
      @ MaxRow() - 1, MaxCol() - 16 PROMPT "3. Bottom right" MESSAGE "Three"
      @ MaxRow() - 1, 0             PROMPT "4. Bottom left"  MESSAGE "Four "
      MENU TO nChoice
      SetPos( MaxRow() / 2, MaxCol() / 2 - 10 )
      IF nChoice == 0
         ?? "Esc was pressed"
      ELSE
         ?? "Selected option is", nChoice
      ENDIF

Compliance

Clipper

Seealso

@…PROMPT, ACHOICE(), SET MESSAGE, SET INTENSITY, SET WRAP, __ATPROMPT()

__MenuTo()

Template

Function

Name

__MenuTo()

Category

API

Subcategory

User interface

Oneliner

Invoked a menu defined by set of @…PROMPT

Syntax

      __MenuTo( <bBlock>,  <cVariable> ) --> nChoice

Arguments

<bBlock> is a set/get code block for variable named <cVariable>.

<cVariable> is a character string that contain the name of the variable to hold the menu choices, if this variable does not exist a PRIVATE variable with the name <cVariable> would be created to hold the result.

Returns

__MenuTo() return the number of select menu item, or 0 if there was no item to select from or if the user pressed the Esc key.

Description

__MenuTo() invoked the menu define by previous __AtPrompt() call and display a highlight bar that the user can move to select an option from the menu. If <cVariable> does not exist or not visible, a PRIVATE variable named <cVariable> is created and hold the current menu selection. If there is a variable named <cVariable>, its value is used to select the first highlighted item.

Menu prompts and messages are displayed in current Standard color, highlighted bar is displayed using current Enhanced color.

Pressing the arrow keys move the highlighted bar. When a menu item is highlighted the message associated with it is displayed on the line specified with SET MESSAGE. If SET WRAP is ON and the user press UP arrow while on the first selection the last menu item is highlighted, if the user press Down arrow while on the last item, the first item is highlighted.

Following are active keys that handled by __MenuTo():

       key            Meaning
       -------------  ---------------------------------
       Up             Move to previous item
       Down           Move to next item
       Left           Move to previous item
       Right          Move to next item
       Home           Move to the first item
       End            Move to the last item
       Page-Up        Select menu item,  return position
       Page-Down      Select menu item,  return position
       Enter          Select menu item,  return position
       Esc            Abort selection,  return 0
       First letter   Select next menu with the same first letter, |return this item position.

Upon exit the cursor is placed at MaxRow()-1, 0 __MenuTo() can be nested without loosing the previous  prompts.

MENU TO command is preprocessed into __MenuTo() function during compile time.

Examples

      // display menu item on each screen corner and let user select one
      CLS
      SET MESSAGE TO MaxRow() / 2 CENTER
      SET WRAP ON
      @ 0           ,  0             PROMPT "1. Upper left"   MESSAGE " One "
      @ 0           ,  MaxCol() - 16 PROMPT "2. Upper right"  MESSAGE " Two "
      @ MaxRow() - 1,  MaxCol() - 16 PROMPT "3. Bottom right" MESSAGE "Three"
      @ MaxRow() - 1,  0             PROMPT "4. Bottom left"  MESSAGE "Four "
      MENU TO nChoice
      SetPos( MaxRow() / 2,  MaxCol() / 2 - 10 )
      IF nChoice == 0
         ?? "Esc was pressed"
      ELSE
         ?? "Selected option is",  nChoice
      ENDIF

Compliance

Clipper

Files

Library is core

Seealso

@…PROMPT, AChoice(), SET MESSAGE, SET INTENSITY, SET WRAP, __AtPrompt()

__AtPrompt()

Template

Function

Name

__AtPrompt()

Category

API

Subcategory

User interface

Oneliner

Display a menu item on screen and define a message

Syntax

      __AtPrompt( <nRow>,  <nCol>,  <cPrompt>,  [<xMsg>] ) --> .F.

Arguments

<nRow> is the row number to display the menu <cPrompt>. Value could range from zero to MaxRow().

<nCol> is the column number to display the menu <cPrompt>. Value could range from zero to MaxCol().

<cPrompt> is the menu item character string to display.

<xMsg> define a message to display each time this menu item is highlighted. <xMsg> could be a character string or code block that is evaluated to a character string. If <xMsg> is not specified or of the wrong type, an empty string (“”) would be used.

Returns

__AtPrompt() always return .F.

Description

With __AtPrompt() you define and display a menu item, each call to __AtPrompt() add another item to the menu, to start the menu itself you should call the __MenuTo() function (MENU TO command). You can define any row and column combination and they will be displayed at the order of definition. After each call to __AtPrompt(), the cursor is placed one column to the right of the last text displayed, and Row() and Col() are updated.

@…PROMPT command is preprocessed into __AtPrompt() function during compile time.

Examples

      // display a two line menu with status line at the bottom
      // let the user select favorite day
      SET MESSAGE TO 24 CENTER
      @ 10,  2 PROMPT "Sunday" MESSAGE "This is the 1st item"
      @ 11,  2 PROMPT "Monday" MESSAGE "Now we're on the 2nd item"
      MENU TO nChoice
      DO CASE
      CASE nChoice == 0           // user press Esc key
         QUIT
      CASE nChoice == 1           // user select 1st menu item
         ? "Guess you don't like Mondays"
      CASE nChoice == 2           // user select 2nd menu item
         ? "Just another day for some"
      ENDCASE

Compliance

C (menu)

Files

Library is core

Seealso

AChoice(), MENU TO, SET MESSAGE, SET INTENSITY, SET WRAP, __MenuTo()