Screens: @Layout and Screen

A Screen is an interactive 5250 screen: it defines its layout (@Layout) and reacts to user events (@Source).

1. Minimal structure

@Properties {
    Type : Screen
    Name : SFORM01
    Description : "Sample screen"
    Path : Screens
}
@References {
    Tables = ["../tables/TLADD50.warp"]
}
@Variables {
    Global {
        Username char(10)
        MyDate   Date
    }
}
@Parameters {
}
@Layout {
    @Label(1,2,&Username)
    @Label(1,70,&MyDate)
    @Input("txtRequestNo", 3, 1, "Request No.: ", &RequestNo, true)
}
@Source {
    Event Init
        &Username = UserId()
        &MyDate   = Today()
    EndEvent
}

Unlike a Program, a Screen doesn’t have its own @Structure — it only references tables to read/write.

2. @Layout controls

Label(x, y, text): static text/variable. x,y = 1,1 (exact corner) is forbidden — DDS rejects it.
Input("Name", x, y, text, &Variable, enabled): editable field. "Name" is what CurrentInput() returns when the cursor lands there. enabled is optional (default true): a literal, &Variable, or a function returning number.
DataGridView("Name", x, y, rows)[...]: grid — see DataGridView.

Control names can be prefixed with @ (@Label, @Input) or not — it’s purely stylistic, same meaning.

3. Standard events

Event	When it fires
`Init`	Once, before the first display.
`Load`	Once, before the first display — typically fills the `DataGridView` with `LoadRow()`.
`Enter`	On pressing Enter (with no function key active).
`Refresh`	On pressing F5, if declared in the project’s `@FunctionKeys`.
`Close`	Fixed to F3 — always runs and closes the screen, no declaration needed.

@Source {
    Event Init
        &Username = UserId()
    EndEvent

    Event Load
        For Each In LADD50 Index LADD5010
        Where SPT25COUNTRY = &nCountry
            &cState = ADSTS50
            LoadRow()
        EndFor
    EndEvent

    Event Enter
        &Control = CurrentInput()
        Message("Active control: " + &Control, Info)
    EndEvent
}

4. Custom function keys

Besides the standard events, you can attach an event to any F1-F24 key (F13-F24 via Shift):

@Source {
    Event 'FindCustomer' 4
        Message("F4 was pressed", Info)
    EndEvent
}

The label shown in the attention line is configured in the project’s .warpcfg @FunctionKeys — see Project.

5. Messages to the user

Message("Rows found: " + String(&nRows, 5), Info)

Error (red), Warning (yellow), Info (normal color). Shown on the next refresh and cleared after one cycle.

6. Next step

If the screen needs to show a list of rows with selection/pagination, see DataGridView.

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