Combo Box Control Properties

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The Combo Box combines an entry box with a list box. It is useful for when you expect string data which usually should be a member of the list, but which also might not be. The Window Designer lets you create either a normal combo box, or a drop-down combo box.

This section only discusses placing the combo box. After you place it, you must format it. See the List Box Formatter dialog for more information on formatting and adding additional functionality to your combo boxes.

See Also:

How to Use a Combo Box

FileDropCombo Control template.File_Drop_Combo_control_template

The Property View presents you with two ways to viewing a control’s properties.

At the top of the Property View, press the categorized button to view a control’s properties by category (the deafult).

Or press the alphabetical button to view a control’s properties in alphabetical order.

This help documents displays the properties in the categorical view

Color

Enter a valid color equate in the TextColor , BackGround, Selected text, Selected fill, or GridColor properties, or press the ellipsis (...) button to select a color from the Color dialog. The Window Designer adds the COLOR attribute to your control declaration.

See ..\LIBSRC\EQUATES.CLW for a list of valid color equates. See Windows Design Issues in the User's Guide for a discussion on using color to enhance your application.

 

Design

Locked

"Freezes" the control so that subsequent data dictionary changes are not applied. You can override the #Freeze attribute for all controls or for individual controls. See Application Options.

Tab Index

Determines the index in the TAB order that this control will follow. The first tab in the order is index zero (0).

To change the TabIndex property immediately while in the Designer, use the Show tab order interface (i.e. on the right-click menu).

If you set the TabIndex property using the property page, the z-order is not updated until you save and exit the Window Designer.

UseVisualStyles

Set to TRUE to display this control in a Visual Style appearance (as if the XP manifest was active)

Extra

Case

Specify case attributes for the entry field portion of the combo box. The entry box can automatically convert characters from one case to another. Uppercase automatically converts to all caps. Capitalize converts to proper case. Default (no attribute) accepts input in the case the user types it.

Column

Set to TRUE if you wish to allow the user to highlight the list component of a multi-column combo box field by field (rather than one row at a time). This provides for spreadsheet grid style movement of the highlight bar. See Also: the COLUMN attribute.

DragID

To specify the type of Drag operations this control will generate, type up to 16 signatures, separated by commas. The DRAGID attribute specifies the REGION control can serve as a drag-and-drop host. DRAGID works in conjunction with the DROPID attribute.

DropID

To specify the type of Drag operations this control will accept, type up to 16 signatures, separated by commas. The Window Designer adds the DROPID attribute to the control, which indicates the control is a valid target for the drag and drop operations identified by the signatures.

EntryMode

Choose either Insert, Overwrite or Default. The Entry Mode applies only for windows with the MASK attribute set. Default accepts input according to the current system settings.

Imm

To generate a message event each time the end user moves or resizes the selection bar, set this property to TRUE. This adds the IMM attribute to the COMBO. You are responsible for the code that executes upon notification of the event.

Mark

Optionally enables multiple item selection. Type in the name of a QUEUE, field or array in the Mark field if you wish to allow the user to select more than one item from the list. The QUEUE field will flag the selected items.

Read Only

The READONLY attribute prevents data entry in this control. Use this to declare display-only data.

Required

The REQ attribute specifies that the control may not be left blank or zero.

VCR

Optionally provide VCR controls. Set the VCR property to TRUE to provide VCR style controls for the list box. Optionally type the name of an entry Field. When the user presses the Locator ( ? ) button, the focus shifts to that field. The user may type in data, then press TAB to scroll the list box to the closest matching entry.

General

Drop

Specifies whether this should be a regular or drop-down combo box. Place a zero in the Drop field for a normal combo box. To create a drop-down combo box, type the number of drop-down elements you wish to be visible. You must resize the combo box after specifying the drop number.

Format

Specifies the print or dispay format of the list box control. Press the ellipsis to call the Format Editor dialog.

From

Fill the From field with the origin of the list data. Generally, this is the label of a QUEUE structure.

Justification

Specify left, center, right, decimal, or default justification. Default justification matches that specified in the data dictionary, if applicable. If you use decimal justification, you set the Offset to allow display of digits to the right of the decimal point.

Offset

Specify an indentation value for the list box item text, in dialog units.

Layout

Indicates the orientation of the control. Left to Right maintains the original layout specified in the Window Designer. Right to Left essentially "flips" the controls’ display as a mirror image of the layout specified in the Window Designer. Default field navigation moves from right to left. The setting in the Application Frame will cascade its setting to all child windows and controls that have the default setting active.

NoBar

Specifies the selection bar appears only when the list box has focus. See Also: the NOBAR attribute.

Picture

Specify the picture token for the control. The picture token you specify appears in the format string, for example, "@S10@." Pressing the ellipsis button lets you select the picture token from the Edit Picture String Dialog.

TextFont

Calls the Font dialog which lets you select the font (typeface), size, style (such as bold or italic), color, and font effects (underline and strikeout) for the selected control or window. As you choose options, the dialog box displays a sample of the selected font.

Use

This defines the USE attribute for the control. Place a variable or field equate label in the Use field. You may specify the variable which will receive the value that the user selects. Or, a field equate label to reference the combo box in program statements.

Help

Alert

Press the ellipsis to open a dialog that lets you add the ALRT attribute to a window or control. When the attribute is set, the window generates an EVENT:AlertKey if the user presses the key(s) you specify in this dialog, while the window has the focus.

Cursor

The Cursor field (the CURSOR attribute) lets you specify an alternate shape for the cursor when the user passes the cursor over the control. The drop-down list provides standard cursor choices such as I-Beam and Crosshair. To select an external cursor file (whose extension must be .CUR), choose Select File from the drop-down list, then pick the file using the standard file dialog.

Help ID

The Help ID field (the HLP attribute) takes a string constant specifying the key for accessing a specific topic in the Help document. This may be either a Help keyword or a context string.

 

A Help keyword is a word or phrase indexed so that the user may search for it in the Help Search dialog. When you fill in the HLP attribute for a button, if the entry box has focus, when the user presses F1, the help file opens to the referenced topic. If more than one topic matches a keyword, the search dialog appears.

 

When referencing a context string in the Help ID field, you must identify it with a leading tilde (~).

Key

Press the desired key or key combination (for example, CTRL+H). The keys you pressed will appear in the Key field, and will be supplied as parameters to the KEY or ALRT attribute for this control.

Message

The Message field (the MSG attribute) lets you specify text to display in the first zone of the status bar when the control has focus.

Tip

The TIP attribute on a control specifies the text to display in a "balloon help" box when the mouse cursor pauses over the control. Although there is no specific limit on the number of characters, the string should not be longer than can be displayed on the screen.

 

Mode

Disable

Disables or 'grays-out' the control when your program initially displays it. The Window Designer places the DISABLE attribute on the control. Use the ENABLE statement to allow the user access to the control

Hide

Makes the control invisible at the time Windows would initially display it. Windows actually creates the control--it just doesn't display it on screen. The Window Designer places the HIDE attribute on the control. Use the UNHIDE statement to display the control.

Scroll

Specifies whether the control should move with the window when the user scrolls the window. By default (False) the control does not move with the window. Set the Scroll property to False to create a control that stays fixed when the user scrolls the window. The Window Designer places the SCROLL attribute on the control when checked.

Skip

Instructs the Window Designer to omit the control from the Tab Order. When the user TABS from field to field in the dialog box, Windows will not give the control focus. This is useful for seldom-used data fields. The Window Designer will place the SKIP attribute on the control. .

Transparent

Specify whether you wish the control background to be Transparent. This instructs Windows to suppress the rectangular region around the text--the background. Normally, Windows will paint this the same uniform color as the window below the control. This adds the TRN attribute.

 

Options

Flat

Check this box to give your list box a "flat" appearance (the list box control is on the same level as the window, and not recessed). Due to a built-in attribute to the runtime library, list boxes used in Drop List and Drop Combo controls are always flat and cannot be modified in the Formatter.

Position

Lets you set the location and size of the control.

The Position tab lets you specify the AT attribute. Filling in the attribute manually is optional--you may set the position and size visually by dragging with the mouse in the Window Designer.

To set the location of the control's Top Left Corner, set an X (horizontal) and Y (vertical) coordinate in Dialog units. The coordinate is relative to the top left corner of the structure containing it, that is, the window or the report band.

To set the control's size, choose from the following options for Width and Height.

Default

The Clarion runtime library determines the size of the control based on the applicable font and picture token.

Full

The control is the full height or width of the window or report.

Fixed

Lets you set a precise width or height in Dialog units on a window, or in thousandths of inch, points, or millimeters on a report.

 

ScrollBars

Horizontal

To add a horizontal scroll bar to your list box, set the Horizontal property to TRUE. Scroll bars only appear when the list of items in the list is bigger than the window.

Vertical

To add a vertical scroll bar, set the Vertical property to TRUE.

 

These options add the HSCROLL, VSCROLL, and HVSCROLL attributes to the control.

Quick Links

 

 

Embeds

Accesses the Embedded Source dialog for points surrounding the event handling for this control only.