Display Options for Fields in Masks

Display options for fields, such as color or title settings are influenced by specifying different field- or mask-field attributes.


Maximum Number of Fields in Masks

The maximum number of fields that can be assigned to a mask is 255. If a mask is opened that contains more fields than this maximum number, DataView will output a message and prevent the opening of the mask. The checking is done in the iwf functions when masks are opened; not when they are created. The following fields are counted:

Attention! The maximum number of records allowed may also not be exceeded after opening the mask, for instance by adding fields in mask triggers or by displaying the internal system fields with [Ctrl+A].


Field Sequence and Field Position

Field sequence and field position in masks are defined in the fields Sequence, Row and Column of the mask-field relation. In lists the fields/columns are automatically positioned next to each other corresponding to the position numbers in the Sequence field. In forms the position numbers define the logical sequence of the fields. The real positions are freely defined in the fields Row and Column. In Mask-Edit state the logical sequence determines the order in which the fields are jumped to when the user navigates with the help of the [Tab] key from field to field. That's why you should always define the real sequence in the mask so that it closely matches the logical sequence.

When creating default masks, DataView automatically takes the field sequence from the table-field relation into the mask-field relation. However, the sequence value is are assigned at incremental steps of . This simplifies to include additional fields. Field positions in default forms are calculated in a way that a standard layout results.


Field Size

The size of fields in masks is defined in the fields Length, Width and Virtual Width of the mask-field relation.

The (row) length in lists is always 1 by default, in forms it can have any value in order to allow you to create multi-line fields. The (column) width is divisible width actually displayed in the mask. The product of length multiplied by visible width is the visible total length. The virtual (column) width defines the maximum number of characters the field can keep. The setting visible visible width < virtual width length is useful whenever only a part of the field content is to be displayed, for instance if there is only little space in the mask. In order to be able to see or edit the complete field entry for such fields, the field/column width can always be dynamically changed in lists ( -> Change Column Width) or the automatically installed -> Edit Window can be opened in lists and forms. Virtual width = 0 means that no virtual width has been explicitly defined.

When defining field dimensions in masks you should observe the following rules:

When generating default masks DataView always sets the virtual width the 0 (with the exception of Longtext fields). DataView determines the visible width for fields of the types Float (F), Integer (I), Money (M) and String (S) from the length specified in the -> type definition of the table-field assignment. Logical fields (L) always have the size 1 row x 1 column, Date fields (D) get the default width 19.


Multi-line Fields

For multi-line fields the same rules apply as for the field size.


Field Format

The format of a field determines the orientation of field contents and the display of decimal digits for fields of the types Field (F), Integer (I) and Money (M). You must explicitly enter the format in the Format field of the field master. It cannot be mask-specifically defined. The following settings are possible:

Field Data Type Possible Formats
F -> Float
M -> Money
(empty) -> flush left orientation
- -> flush right orientation
-n -> flush right orientation with n digits after the point/comma
I -> Integer (empty) -> flush left orientation
- -> flush right orientation

Please note that field contents my disappear in case of flush right orientation if a virtual field width has been defined.

Example: Assume the type definition in the table-field relation is F.4, The format definition in the field master is -3. This results in the display xxxxxx.xxxx in the database table and the flush-right display xxxxxx.xxx in a mask (last decimal digit not displayed).


Field Title

The field title in lists is the column header for the field. In forms the title can have any position at the field; usually above or next to it.

Field titles are mask-independently defined in the Title field of the field master. If the field is displayed in several masks you can mask-specifically overwrite it in the Title-M field of the mask-field-default relation. Position and size of titles in forms can be mask-specifically set in the fields R-Tit, C-Tit, L-Tit and W-Tit of the mask-field-default relation. The position values are always relative to the position values of the corresponding field. DataView ignores any such entries for lists. A title in lists automatically has a length of one row and the same width like the field/column.

Field titles play a central role for the integration of -> graphical objects and images in forms.

Color Settings for Fields and Field Titles

The mask-specific colors for fields are controlled in the Video field of the mask-field relation, for field titles in the V-Tit field of the mask-field-default relation. For both objects you can define the background and text color independently:

Entry Color
First Digit (0 ... 5) Foreground color of the field (field entry) or the field title (title text)
Second Digit (0 ... 5) Background color of the field or the field title

In the selection menu of the video field the color for the digits are displayed.

For further information about these settings, please refer to the online help Getting Started > How to .. > System Configurations > Preferences.

Global field colors for hyperlink fields as well as global field title colours in Mask-Edit state can be set with the help of the default variables VIDEOHYPERLINK, VIDEOEDIT and VIDEOMANDATORY. If colour values have been defined for the variables, they are valid in all masks of the application and take presedence over mask-specific colour settings.

Note! Color settings defined using the positive or negative value assignment 0 ... 5 (field background) or -0 ... -5 (color of the field content with field background color = default) (up to DataView-Version 3.0-03), will still be correctly displayed.


Font Settings for Fields and Field Titles

You can separately define character fonts for field contents, title texts, and logical fields (in lists only).

For further information about these settings, please refer to the online help Getting Started > How to .. > System Configurations > Preferences.


Visibility of Fields

Fields in masks can be either visible or invisible. This is controlled in the Access field of the mask-field relation (empty entry = field invisible, any other access setting = field visible). Invisible fields are important when graphical objects and images are imported into forms, when two key fields exist in link masks, or simply if fields are temporarily not to be displayed in masks. Please note that invisible fields will not be filled in an Insert- or Copy operation.


Display of Logical Fields (Check Boxes)

Logical fields are displayed as check boxes in lists and forms.

The size 1x1 and the focus size is unchangeable. The focus is the sensitive area around the button within which a mouse-click sets or resets it. Font and character specifications are not required, the ON character (check) is hard-coded. Field colour settings are only effective for lists.

A checkbox knows the following five states: OFF, ON, NULL, NOT NULL and UNSET. . State No 4 is only valid in Query mode. It allows queries on logical fields which are NOT NULL, i.e. which either have the value ON or OFF. Each of these four states is displayed in a different way.

State Appearance of the check box
OFF empty and white
ON checked on white
NULL (UNSET) empty and grey
NOT NULL checked on grey

The first (untouched) grey background of the logical field means "unset" while if ever changed in query mode the grey background means "NULL".

If the logical field is an obligatory field, it must not have to value NULL. For this reason not all states are available when a check box is edited in Insert-and Update modes.

Field Mode Possible states
obligatory field INSERT NULL only directly after Insert OFF ON
UPDATE - OFF ON
no obligatory field INSERT or UPDATE NULL OFF ON

If an obligatory logical field is not explicitly set to ON or OFF directly after Insert, the record cannot be stored. A corresponding message informs about that.


Significant Fields

Significant fields are fields whose contents characterize records in a special way. These are for instance unique number fields or item identifiers. Such fields should always be displayed first in a mask (Sequence field in the mask-field relation). Starting with the first field you can then classify a number of fields as significant. This is done in the sign field of the mask master. The classification has the following effects on the mask layout and the mask functions:


Calculation Fields

Calculation fields are fields that are used to display database-independent information in masks. They must be filled with data via individual application-specific userexits. Usually data are copied from other fields or calculated with the help of a formula.

Calculation fields are either created directly in the Field Data form or in the table fields sub-lists of the model object forms. Please observe the following information:

Userexits that supply calculation fields are usually installed at the Post_Action- or at the Pre_Mask trigger. Please observe the following information: