How to Copy to and Paste from the Calculator Within a Screen

• Microsoft FoxPro for Windows, version 2.6a
• Microsoft FoxPro for MS-DOS, version 2.6a
• Microsoft FoxPro for Macintosh, version 2.6a

SUMMARY

If the calculator is activated while the READ generated by the Screen Builder is in effect, it will not become the window on top and may not be visible if the screen covers the area where the calculator was activated.

This article shows by example how to bring up the calculator on top of the READ window, as well as how to place the value of the current GET field in the calculator, and return the result of the calculation to the GET.

MORE INFORMATION

Step-by-Step Example

The following steps lead you through the process of incorporating this functionality in the context of a screen set. Also shown in this example is the ability to transfer values between the screen and the calculator.

Assumptions:

• A screen exists that contains at least one numeric field formatted with two decimal places.
• A push button has been added to call the calculator.
• The Cycle option under the Window pad of the System menu bar is available.
• The GET fields on the screen are referencing the database fields directly rather than through memory variables.

1. Modify the screen that will access the calculator.

2. Bring up the Setup Code window, and enter the following:

   * set up variable to hold name of selected field

      curfld = ""      && current field to copy from and paste to
      * in FoxPro for Macintosh add the following line to keep the READ
      * window visible in front of the FoxPro screen
      #WCLAUSES IN SCREEN      && FoxPro for Macintosh only
   
   

3. Open the Cleanup and Procedures window, and enter the following:

      IF WVISIBLE("CALCULATOR")         && exiting program, so
          DEACTIVATE WINDOW CALCULATOR  &&   close the calculator
      ENDIF
   
      PROCEDURE paste
      * Called when the calculation is completed
      REPLACE (curfld) WITH VAL(ALLTRIM(STR(_CALCVALUE,10,2)))
      SHOW GETS             && update the display with the new value
      DO waste              && close the calculator and clean up
   
      PROCEDURE waste
      * Called to close calculator and clean up status bar
      KEYBOARD CHR(23)      && close window
      POP KEY               && restore previously saved ON KEY LABEL set
      SET MESSAGE TO ""     && erase message on status bar
      SET MESSAGE TO        && reset to default messages
   
   

4. In VALID clause of each participating numeric field, enter:

      curfld=VARREAD()      && store the current field name
   
   

5. Within the VALID clause of the Calculator push button, enter:

   _CLIPTEXT=ALLTRIM( STR( EVALUATE( curfld ), 10, 2) ) &&store val KEYBOARD "{CTRL+F1}" && cycle focus to the calculator

      PUSH KEY CLEAR        && store any ON KEY LABEL definitions
      ON KEY LABEL F4 KEYBOARD "{CTRL+V}"   && Copy GET to calc
      ON KEY LABEL F5 DO paste              && Paste calc to GET, exit
      ON KEY LABEL F8 DO waste              && Exit calculator, no paste
      ON KEY LABEL ESCAPE DO waste          && (same as above)
      SET MESSAGE TO "    F4 = Copy GET    F5 = Paste, exit    F8 = Exit"
      ACTIVATE WINDOW CALCULATOR
   
   

6. Generate the .SPR and use the DO command to execute the screen.

7. To demonstrate the functionality, assume that a six percent increase must be added to a particular field. Press the TAB key to move to one of the numeric fields that has a Currency format [ @$ 9,999.99 ]. Enter the value of 123. Select the Calculator button, and press the F4 key.

   The field value will be inserted into the calculator. Multiply the value by .06 (asterisk-period-zero-six-enter), which should be 7.3800. Add this result to the original value (plus_sign-F4-enter), which should equal 130.3800. At this point, press the F5 key to exit the calculator. The value of $130.38 will be inserted into the field.