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PegComboBox

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Members Styles Signals

Overview Derived from class PegVertList The PegComboBox class provides a compact container for a list of objects. The PegComboBox object must be "opened" to view the list of objects. The combo box is opened via the drop down arrow to the right of the combo box. The combo box is "closed" once an object is selected from the list, leaving only the selected object visible in the combo box. The combo box is also closed when it loses input focus. The PegComboBox object sends a signal notification to its parent window if both the PegComboBox and the child selected from its list have a non-zero object ID. The last child object added to the combo box will be displayed at the top of the combo box if the Add() function is used to add children. The order of display can be reversed by using the function AddToEnd() to add children to the combo box. If PegPrompt objects are added to a PegComboBox, the style flags for the PegPrompt objects should include FF_NONE|AF_ENABLED|TJ_LEFT for correct display. Although a PegPrompt object is normally not selectable, the AF_ENABLED style flag must be used when the PegPrompt object is added to a combo box so that the prompt object can be selected.

See Also

PegVertList

PegHorzList

PegWindow

Styles

The PegComboBox class supports the following style flags:

Note that scrolling of the object list within a PegComboBox object is enabled using the SetScrollMode() function, as for all windows derived from the PegWindow class.

Signals

The PegComboBox class generates the following signals:

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Members

Constructors:

	PegComboBox(const PegRect &Rect,
	WORD wId = 0,
	WORD wStyle = FF_THIN)

This constructor creates a PegComboBox object at a specific location within a rectangle specified by parameter Rect. The vertical dimension of the rectangle determines the height of the combo box when open. The closed height is determined by the tallest of the child objects within the combo box.

Public Functions:

	void Draw(void)

The PegComboBox class overrides the Draw() function to display the combo box border.

	SIGNED GetOpenHeight(void) {return miOpenHeight;}

This inline function returns the height (in pixels) of the combo box when open.

	BOOL IsOpen(void) {return mbOpen;}

This inline function returns TRUE if the combo box is currently open, else FALSE.

	virtual SIGNED Message(const PegMessage &Mesg)

The PegComboBox class overrides the Message() function to catch the drop down arrow selection message and the PM_KILLFOCUS system message, both of which require the combo box to be opened or closed and redrawn.

	void Resize(PegRect NewSize)

The PegComboBox class overrides the Resize() function to keep the drop down arrow button positioned at the upper right hand corner of the combo box when the combo box is moved.

Protected Members:

	BOOL mbOpen

This boolean variable is TRUE if the combo box is open or FALSE if it is closed.

	SIGNED miOpenHeight

This variable provides the height (in pixels) of the combo box when open.

	SIGNED miCloseHeight

This variable provides the height (in pixels) of the combo box when closed.

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Examples

The following example illustrates a PegComboBox object:

The following code fragment creates a PegComboBox object and adds several PegPrompt objects to the combo box. The height of the open combo box will be 140 pixels. The combo box is configured to include a vertical scroll bar. The initial item selected will be item index 5 within the combo box. Note that list items are numbered from 0.

void MyWindow::AddComboBox(void)
{
    PegRect ListRect;
    ListRect.Set(10, 10, 90, 150);

    PEGCHAR cTemp[20];
    pList = new PegComboBox(ListRect);

    strcpy(cTemp, "Select");
    for (iLoop = 10; iLoop > 0; iLoop--)
    {
        itoa(iLoop, cTemp + 6, 10);
        pList->Add(new PegPrompt(0, 0, cTemp, iLoop,
            FF_NONE | TJ_LEFT | AF_ENABLED | TT_COPY));
    }

    pList->SetScrollMode(WSM_VSCROLL);
    pList->SetSelected(5);
    Add(pList);
}

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