Home

PegTextBox

Examples Index

Members Styles Signals (none)

Overview Derived from class PegWindow and PegTextThing The PegTextBox class provides a multiline text display control with windowing features. The font, color, size and scrolling mode can be modified to give PegTextBox objects a wide variety of appearances. The text within a PegTextBox object is normally left justified. Right and center justification are also supported. The textbox size (the maximum number of characters which the textbox can accommodate) is established when the textbox is constructed. The size can subsequently be adjusted if necessary to meet the dynamic needs of your application. Lines of text that exceed the client width of the textbox are wrapped by default to extend across two or more lines. Lines wrap at whitespace, comma or hyphen characters. If a suitable breaking point cannot be found, the line will wrap at the last character which fits within the width of the client area. If a PegTextBox object is used to display a long section of text that requires more text lines than will fit in the visible TextBox client area, a vertical scroll bar can be added to the window. The maximum number of lines of text that can be maintained for display is 100, unless modified by your KwikPeg Library configuration. Automatic vertical scrolling can be enabled by calling the SetScrollMode(WSM_AUTOVSCROLL) member function of the PegWindow class from which the PegTextBox object is derived. Each PegTextBox object maintains an array of line break offsets into the block of text displayed in the window. Using this array, new lines of text can be quickly displayed as the text is scrolled up or down. You can access these line start offsets if needed using member functions. The PegTextBox class also catches PM_KEY messages in order to detect PK_PGUP and PK_PGDN requests which it services to scroll the displayed text up or down, one page at a time. Characters can be inserted into the textbox using the DataSet() function. Any characters which would extend beyond the textbox limit are lost. Hence, insertion clipping occurs at the end of the textbox character array. Characters can also be appended to the end of the textbox using the Append() function. If any appended characters would extend beyond the textbox limit, an equivalent number of characters are deleted from the beginning of the textbox character array. Hence, when characters are appended, clipping occurs at the head of the textbox character array. The PegTextBox class does not provide text editing support. The text displayed in the textbox can be modified by your application using the DataSet() or Append() member functions. For a full editable control, use a PegEditBox object.

See Also

PegPrompt

PegString

PegEditBox

Styles

The PegTextBox class supports the following style flags:

	Top of page

Members

Constructors:

	PegTextBox(const PegRect &Rect,
	WORD wId = 0,
	WORD wStyle = FF_RECESSED|EF_WRAP|TJ_LEFT,
	PEGCHAR *Text = NULL,
	WORD wMaxChars = 1000)

This constructor creates a PegTextBox object at a specific location within a rectangle specified by parameter Rect. The rectangle defines the mReal position of the window.

The textbox object ID, window style and initial text can all be specified. Parameter wMaxChars specifies the size of the textbox character array, the maximum number of characters that the textbox can hold.

Public Functions:

	virtual void Append(const PEGCHAR *pText,
	BOOL bDraw = TRUE)

This function appends the indicated text to the current textbox string value. If any appended characters would extend beyond the textbox limit, an equivalent number of characters are deleted from the beginning of the textbox character array. The append function facilitates creation of terminal style windows.

If parameter bDraw is TRUE, the textbox will be redrawn to reflect the newly added text.

	virtual void DataSet(const PEGCHAR *Text)

The PegTextButton class overrides the DataSet() function to permit the installation of the new text string referenced by Text. The textbox client area is invalidated. Line offsets are recalcalculated and the scroll bars, if any, are adjusted if necessary.

	virtual void Draw(void)

The PegTextBox class overrides the Draw() function to display the textbox border and text.

	PEGCHAR *FindLinePointer(SIGNED iLine)

This function returns a pointer to the text which begins at line iLine. Lines are numbered from 0. Be aware that the text line is NOT '\0' terminated. If iLine exceeds the number of lines present in the textbox, the function returns NULL.

	virtual void GetHScrollInfo(PegScrollInfo *Put)

The PegTextBox overrides the PegWindow::GetHScrollInfo function to make the scroll bars operate relative to the contained text.

	WORD GetLineIndex(SIGNED iLine)

This function returns the index into the textbox character array at which text line iLine begins. Lines and character indices are numbered from 0. If iLine exceeds the number of lines present in the textbox, the function returns 0xFFFF.

	PEGCHAR *GetLineStart(SIGNED iLine,
	SIGNED *pLength)

This function returns a pointer to the text which begins at line iLine. Lines are numbered from 0. Be aware that the text line is NOT '\0' terminated. If iLine exceeds the number of lines present in the textbox, the function returns NULL.

If pointer pLength is not NULL, this function will set *pLength to the number of characters (excluding '\r' or '\n' characters) present in line iLine.

	WORD GetMaxChars(void)

This inline function returns the textbox character array size, the maximum number of characters which the textbox can hold.

	WORD GetTopLine(void)

This inline function returns the line index of the line currently displayed at the top of the textbox. Lines are numbered from 0.

	virtual void GetVScrollInfo(PegScrollInfo *Put)

The PegTextBox overrides the PegWindow::GetVScrollInfo function to make the scroll bars operate relative to the contained text.

	WORD GetWidestLine(void)
	{return miWidestLine;}

This inline function returns the width (in pixels) of the widest line of currently displayed text in the textbox. The widest line may not be visible in the client area.

	SIGNED LineCount(void)
	{return miTotalLines;}

This inline function returns the total number of lines of text contained in the textbox. The result is the total number of lines available, not the number of lines actually visible.

	BOOL LineDown(void)

This function scrolls the textbox down one line. Your application can use this function to scroll the textbox whenever required, independent of the scroll bar controls.

	BOOL LineUp(void)

This function scrolls the textbox up one line. Your application can use this function to scroll the textbox whenever required, independent of the scroll bar controls.

	void MarkLine(SIGNED iLine)

This function "marks" text line number iLine. Lines are numbered from 0. The marked line of text will be displayed using the PCI_STEXT and PCI_SELECTED foreground and background colors.

	virtual SIGNED Message(const PegMessage &Mesg)

The PegTextBox class catches several screen pointer and keyboard messages to provide single line and paged scrolling of the text.

	virtual void Resize(PegRect NewSize)

The PegTextBox class overrides the Resize() function to recalculate the layout of the displayed text lines to reflect the result of the resizing operation.

	void RewindDataSet(const PEGCHAR *pText)

This function assigns the text string pText to the PegTextBox character array. The new text replaces any current text. The textbox line offset array is reset to match the new text. The display is positioned with the first line of text at the top of the textbox client area.

	virtual void SetFont(PegFont *pFont)

The PegTextBox class overrides the SetFont() function to recalculate the layout of the displayed text lines to reflect the result of the font change.

	void SetMaxChars(WORD wMax)

This function can be used to modify the size of the textbox character array, the maximum number of characters the textbox can hold.

	void SetTopLine(SIGNED iLine)

This function scrolls the textbox so that line iLine is positioned at the top of the textbox client area. Lines are numbered from 0. If iLine exceeds the number of available lines or is such that the displayed text lines would would require more lines of text than are present in the textbox, the top line is adjusted so that the last visible line is the last available line text. If the number of lines following line iLine is not sufficient to fill the client area, line iLine will be positioned at the top of the textbox with the available lines following and the remainder of the textbox cleared of text.

	void SetTopLineToEnd(void)

This function will redraw the textbox so that the last text line is visible at the bottom of the textbox. The function is equivalent to SetTopLine(LineCount()).

Protected Members:

	SIGNED miWidestLine

This variable indicates the width of the widest textbox line, in pixels.

	SIGNED miLeftOffset

This variable indicates the distance (in pixels) that the textbox has scrolled horizontally from the anchor point used to identify the start of a line.

	Top of page

Examples

The following examples illustrate different styles of PegTextBox objects.

Top of page

Home

Index

Copyright © 2000-2003