HP 3000 Manuals HP 3000 Manuals
Overlays and Variable Starting Lines Overlays are two or more forms that are displayed so that portions of all the forms are visible at the same time. You can create overlays using the start line number and number of lines to clear form attribute entries. For example, a form that starts on line 13 and clears 12 lines occupies the bottom half of the screen, leaving the top half of the prior form displayed unchanged. This type of overlay can be used to build a screen with several forms that can be combined dynamically at runtime. For example, this feature can be used in an inquiry application. Another example is a form that does not clear any lines, in which case both forms are displayed at the same time. Input capable fields on the first form are no longer active after the second form is displayed. Input capable fields on the second form whose screen positions coincide with fields or constants from the first form have the field or constant as its initial value. This type of overlay can be used to create applications that use the output data from one form as input data to the next form with the combinations taking place dynamically at runtime, perhaps to model a new entry after an existing entry of a different type in a database. Variable Starting Line forms are forms that start on a line number supplied by the RPG program at runtime. The start line number form attribute must be V, and the "KSTART" file continuation record must contain the name of a numeric field two positions long with zero decimal places. Load the starting line number for the form into the field before you display the form. An example of this feature is a data entry application that uses a form that is one or two lines long. The same form can be displayed at different locations on the screen so that the user can see the last few transactions while entering the current transaction. An example of overlays and variable start line forms used together is an order entry application that begins with a small form that occupies the top few lines of the screen to enter header information. The next form is a one-line form that is displayed once for each detail line of the order, moving down the screen a line at a time. The final form occupies the last line or two of the screen and contains the totals for the order. An entire order (assume the maximum detail lines is 15) can be seen at one time even though it was entered on many different forms.