What is a Dialog box? A Dialog box is a window or “form” that contains other child windows or “controls” that have a specific appearances and pre-defined behaviors. In many cases the appearance and behaviors of these controls can be modified by a program to enhance the usability of the control. The use of a dialog box can be as simple as displaying a warning message or it can be complex enough to represent an entire application. It’s all up to the programmer.

Dialog Styles There are currently two basic techniques you can use to render a dialog with Comet. –A popup dialog Standalone Usually modal Best for simple message exchange but can also be used for complex user input. –A embedded dialog Child of the “view” window Always modeless Best for complex forms with many fields.

Popup Dialog A typical popup dialog contains a title bar, a system menu and user controls. It is modal in that the parent window (COSW or another dialog) is disabled and will remain so until the dialog is destroyed. The underlying screen may still be visible under the dialog. A popup dialog can contain a complex set of controls or it can display a simple message.

Fitting it all in – Tabbed Dialogs Most applications manage far more data than can be displayed on the screen. For legacy Comet applications the solution to this problem is to break up the data into manageable groups and then display each group separately from the others. While this technique can also used in a windowed application, there are better ways to handle this problem. A “tabbed” dialog is a dialog that contains a tab control that looks and behaves in a manner similar to a notebook or binder. The user simply clicks on a “tab” and the “page” associated with that tab is displayed in the display area of the tab control. The display area inside the tab window contains the fields that pertain to a group of related fields. In the past, all of the controls for every tab had to be individually show, hidden, and maintained based upon the tab that was clicked. This is no longer the case.

Tabbed Dialog Layout A typical tabbed dialog will contain a tab control that will define the area that each page will be share. In addition, the dialog will contain other controls that are common to all of the pages the dialog will support.

Embedded Dialog A embedded dialog appears to be integrated directly into the COSW “view” window. This technique can provide seamless transitions from a legacy Comet application to a windowed application. There are two ways to display a embedded dialog. The first is to size the COSW window to fit the dialog. Because the user will see the window size change this is the least attractive of the two. The second is to leave COSW as is and blend the dialog into the existing window (preferred). The only “catch” to this method is that the window must already be large enough to contain the entire dialog.

What kind of Controls does Comet Support? The following controls are currently supported by Comet: –Buttons including PushButtons, RadioButtons, and CheckBoxes. –Static Text –Edit –GroupBox –ListBox –ComboBox –ScrollBar –Spin –Progress –Tab –Picture –IPAddress –ListView –TreeView –DateTimePicker –MonthCalendar

PushButton Control The PushButton control is a round-cornered rectangle containing text. The text is centered in the control. The control sends a message to its parent whenever the user chooses the control.

RadioButton Control RadioButtons are used to select one of several options, usually within a dialog box. A radio button contains a small circle with text next to it. When selected, the circle has a smaller, filled circle inside it. Selecting one button in a set deselects the previously selected button, so only one of the options in the set is selected at a time.

CheckBox Control The CheckBox control is a small rectangle (check box) that has the specified text displayed next to it (typically, to the right). When the user selects the control, the control highlights the rectangle and sends a message to its parent window.

StaticText Control The StaticText control provides a convenient way to display text on dialog boxes and other windows. Static text controls often serve as labels for other controls.

GroupBox Control The GroupBox control is a rectangle that groups other related controls together. The controls are grouped by drawing a border around them and displaying the given text in the upper-left corner.

Edit Control The Edit control is a rectangular control window typically used in a dialog box to permit the user to enter and edit text by typing on the keyboard.

ListBox Control The ListBox control is a rectangle containing a list of strings (such as filenames) from which the user can select. The ListBox can be restricted to one selection at a time or it can allow multiple selections.

ComboBox Control The ComboBox control consists of either a static text box or an edit box combined with a list box. The list box can be displayed at all times or pulled down by the user. If the combo box contains a static text box, the text box always displays the selection (if any) in the list box portion of the combo box. If it uses an edit box, the user can type in the desired selection; the list box highlights the first item (if any) that matches what the user has entered in the edit box. The user can then select the item highlighted in the list box to complete the choice.

ScrollBar Control The ScrollBar control is a rectangle that contains a scroll box and has direction arrows at both ends. The scroll-bar control sends a notification message to its parent whenever the user clicks the mouse in the control. The parent is responsible for updating the scroll-box position. Scroll-bar controls can be positioned anywhere in a window and used whenever needed to provide scrolling input.

Slider Control A slider control, also called a trackbar control, lets a user select from a range of values by moving a slider. The volume controls in the Windows operating system are slider controls.

Spin Control A Spin control (also known as an up-down control) is a pair of arrow buttons that the user can click to increment or decrement a value, such as a scroll position or a number displayed in a companion control. The value associated with a spin button control is called its current position. A spin button control is most often used with a companion control, called a "buddy window."

Progress Control A Progress control is a window that an application can use to indicate the progress of a lengthy operation. It consists of a rectangle that is gradually filled with the system highlight color as an operation progresses.

Tab Control A Tab control defines multiple pages for the same area of a window or dialog box. Each page consists of a set of information or a group of controls that an application displays when the user selects the corresponding tab.

Picture Control A Picture control allows the user to display a picture in your dialog. The developer can specify a bitmap or icon resource to be displayed in the control. The picture control can also be used to provide etched vertical and horizontal lines or a frame around other controls.

IPAddress Control The IP address control allows the user to enter a numeric address in Internet protocol (IP) format. This format consists of four three-digit fields. Each field is treated individually; the field numbers are zero- based and proceed from left to right. For Comet users this control is pretty useless.

ListView Control The ListView control displays a collection of items each consisting of an optional icon (from an image list) and a label. In addition to an icon and label, each item can have information displayed in columns to the right of the icon and label. In “report view” each item appears on its own line, with additional information arranged in columns to the right. The leftmost column contains the small icon and label, and subsequent columns contain subitems as specified by the application. Currently Comet does not support icons in a ListView control.

TreeView Control A TreeView control is a window that displays a hierarchical list of items, such as the headings in a document, the entries in an index, or the files and directories on a disk. Each item consists of a label and an optional bitmapped image, and each item can have a list of subitems associated with it. By clicking an item, the user can expand and collapse the associated list of subitems. Currently Comet does not support bitmaps in a ListView control.

DateTimePicker Control The DateTimePicker control provides a simple interface to exchange date and time information with a user. This interface contains fields, each of which displays a part of the date and time information stored in the control. The user can change the information stored in the control by changing the content of the string in a given field. The user can move from field to field using the mouse or the keyboard.

MonthCalendar Control The month calendar control provides the user with a simple calendar interface, from which the user can select a date. The user can change the display by scrolling backward and forward, from month to month.