Chapter 5: Painting Screens

In this chapter, you learn about the Screen Painter, paint a screen and assign field attributes.

Learn about the Screen Painter

Goal

In this section you learn what the APS Screen Painter does, and you set screen design options.

The APS Screen Painter lets you paint character-based screens that are intuitive and easy to use. You first paint text, input/output fields, and then blocks of fields that accept multiple record occurrences. You then specify field names, field attribute and edit criteria, and generation parameters. The APS Generators retrieve this screen information from the Application Dictionary to produce native screen source code.

A character screen consists of fields and blocks of fields that you paint on a blank screen. You paint two types of fields in the APS Screen Painter:

Input/Output (I/O) fields that let end users view, add, update, and delete information. You paint I/O fields by typing a string of Xs.
Text fields that display text, such as prompts for I/O fields, column headings, screen headings, section headings, and explanatory text. You paint text fields by typing any text you want.

Using a series of related screens in the Screen Painter, you can also:

Assign field attributes, such as field protection, brightness, cursor positioning, and color.
Assign field edits, such as an internal picture, edit mask, or date format, or test for a range of valid values the end user inputs into I/O fields.

The Screen Painter also provides editing and design options to help you paint the screen. For example, you can specify where the Command field automatically appears on your screen, and can determine whether your text displays in upper case, lower case, or both.

Procedure

Start this procedure where the last one ended -- in the APS Screen Painter. When the Screen Painter first appears, it is blank except for a line indicating the Command field.

Figure 5-1: Creating a Screen

Type profile on the line indicating the Command field. The Profile screen displays showing the current values in your user profile of screen design options.

Figure 5-2: Access Your User Profile

Define the following characteristics for your session:

Command location	Type top, so the Command field always appears in the upper-left corner, or type bottom for the lower-left corner, if you prefer.
Caps on/off	Type off, so text fields remain in the case (upper or lower) you enter them.
Nulls on/off	Type on, so you can insert data directly into a row.
Keys on/off	Type on, so the PF key definitions display at the bottom of your screen.

Press PF3 to return to your blank screen.

Checkpoint

You have set your screen design options and are ready to paint the Parts Update screen.

Help

The screen design options you select remain in effect for all application screens until you change them, either in the current editing session or a subsequent one.

The Screen Painter has an extensive help facility that you can select from the action bar, or access from your screen by pressing PF1.

Hints

Other functions you can perform in the Screen Painter are:

Paint blocks of fields that accept multiple record occurrences of one or more records.
Select I/O fields, complete with definitions, attributes, text prompts, and edits, from the APS Data Element Facility.
Tailor screen generation for a particular target environment.

Paint the Screen

Goal

In this section, you paint the text and I/O fields for the Parts Update Screen, paint a field for system messages, paint a field to save the database key, and assign a title to the screen.

When you paint a screen, you generally:

Design the layout of the screen, with text and input/output (I/O) fields that appear as Xs, as shown in Figure 5-3. This layout is called a screen mock-up.
Paint an I/O field for system messages. APS requires a system message field for any screen that assigns field edits in order to receive screen field edit messages. The system message field is the last I/O field on the screen in Figure 5-3.
Paint a savekey field for records that are read in one execution of the program and reread in the next execution. For example, in a program that updates the database, such as this one:
- The first execution of the program reads the record and displays it on the end user's screen.
- The second execution of the program may reread the record before updating it. To do this, APS must save the key of the record when it reads it for the first time.
The savekey field is the unlabeled I/O field of nine bytes that precedes the system message field in Figure 5-3.
Assign a screen title that appears in all generated APS documentation and in the screen flow scenario prototype, which you perform in the next chapter, Prototype the Screen Flow.

Procedure

Start this procedure where the last one ended -- on a blank screen in the Screen Painter. Figure 5-3 illustrates the Parts Update screen to paint.

Figure 5-3: Paint a Screen Mock-Up

Type the APSU screen layout exactly as shown in Figure 5-3.
Press Enter.
To assign a screen title, type title in the Command field.

Figure 5-4: Enter the TITLE Command
Press Enter to display the Screen Title screen.

Figure 5-5: Assign a Screen Title
Type the screen title, as shown in Figure 5-5.
Press PF3 to save your work and return to the Parts Update screen-painting screen.

Checkpoint

You have painted your screen mock-up and are ready to assign attributes to the I/O fields.

Help

To change a field length, move the cursor to the Xs designating the field and type in your changes. You can space over or delete the Xs representing the field, or extend the field with more Xs.

To delete screen text, use the Delete key to erase all of part of a field or row.

Hints

The screen title does not appear on your screen mock-up; it displays in the Scenario Painter when you test the screen.

Assign Field Attributes

Goal

In this section, you assign various attributes to each I/O field.

The APS Screen Painter supports full and extended 3270 attribute capabilities, including:

Color
Underline, blinking, and reverse video features
Cursor positioning when the screen displays to the end user
Bright and dark intensity
Numeric keyboard locking
Field protection
Assignment of initial value
Light pen sensitivity

For example, you can enhance the presentation of I/O and text fields by changing the default values for attributes such as intensity, color, and underlining. For I/O fields, you can modify attributes to protect a field from data entry and position the cursor on a particular field. Additionally, you can change the APS default field name to something descriptive to the application.

APS assigns default attribute values to each field for you. You can quickly override the default by typing over the value.

Procedure

Start this procedure where the last one ended -- on the Parts Update screen painting screen.

Type fa in the Command field and press Enter. The Field Attribute screen displays.
For the function field, type function in the Name field to change the default field name.
For the Part Number field, type part-nbr in the Name field.
For the Description field, type short-desc in the Name field.
For the Units field, type units-instock in the Name field.
For the Base Price field, type base-price in the Name field.
For the Dimensions field, type dimensions in the Name field.
For the next field, the savekey field, do the following:
1. Type savekey in the Name field.
2. Type p in the Ty(pe) field to change the field from unprotected to protected, so the end user cannot enter data.
3. Type d in the In(tensity) field to change the field from normal intensity, to dark (hidden), so the field does not display on the screen that the end user sees.
For the system message field, do the following:
1. Type sysmsg in the Name field.
2. Type p in the Type field to protect the field from data entry.
3. Type b in the Intensity field to change the field from normal intensity to bright (highlighted).
Press PF3 to save the system message field attributes. Press PF3 again to save the screen design and return to the Application Painter.

Checkpoint

You have completed screen painting. You are now ready to prototype your screen flow where, in an actual application development cycle, you demonstrate the application to your end user.

Hints

An I/O field name can have a maximum of 16 characters. Text fields do not have names because programs do not reference them.

If you give a screen field the same name as its corresponding database field, APS Online Express automatically maps the relationship for you, prefixing the field name with the screen name; otherwise you must map the screen field to the database in your program.

If the same field appears on several screens, give it the same name on each screen. APS lets you pass data between identically named fields on different screens during scenario prototyping and ISPF prototyping.