Programming Guide - Actian

Table Field OperationsHow You Can Use Navigation Keys to ScrollHow You Can Use Single-character FindThe up and down arrow keys select a new row and cause scrolling if that row isnot visible. Page Up and Page Down scroll a single page. The Home and Endkeys scroll to the first or last page of the table field.Note: If the current field is changeable, the navigation keys apply to that field,provided the field is of a type that uses that particular key.When a user positions the cursor in a column that has an entry field as itsprotofield and types a letter or number, the cursor moves to the first rowwhose value in that column begins with the specified letter or number. Eachtime the user types the character, the cursor moves to the next row whosecolumn value begins with that character.In searching for a specified character, when the cursor reaches the last row ofthe table field, it loops back to the first row.Because typing in a field whose mode is changeable actually displays the valuein the field, you can use single-character find only when the column isLandable but not Changeable.You can disable this feature for a column in either of the following ways:• Use the Property Inspector to set the HasSingleCharacterFind attribute.• Set the HasSingleCharacterFind attribute in your 4GL code.For example, the following code disables this feature for the vid_no columnof the vlist table field:field(vlist[*].vid_no).HasSingleCharFind = FALSE;To implement a custom find operation for a table field whose bias ischangeable, use the ArrayObject's Find method. For an explanation aboutusing the Find method, see How You Can Scroll Indirectly with the Find Method(see page 240).How You Can Trigger SetValue, Exit, and Scroll EventsWhen a user scrolls through data using the single character find feature or anarrow key, the action triggers a SetValue event, an Exit event, or both, for thefield being exited.When a user uses the scroll bar, a SetValue or Exit event is triggered only ifthe row that had the current input focus scrolls out of the display. If thecurrent row remains displayed, you can determine whether the user scrolledthrough the data by using a Scroll event.238 Programming Guide