NAME¶
TextDisplay - unstructured text display
SYNOPSIS¶
#include <InterViews/textdisplay.h>
DESCRIPTION¶
A TextDisplay manages and displays an array of lines of text. Operations are
provided to insert and delete lines, to insert and delete text within a line,
and to scroll the display. TextDisplays are typically used to implement
interactors that require non-trivial display of unstructured text.
The array is addressed by a line number and an index into the line. Text can be
inserted or deleted at arbitrary positions. By default, the first character in
line number zero is positioned with its top left corner at the top left corner
of the TextDisplay. The display is automatically updated following
modifications to the text or when scrolling. Each character in the array has
an associated text style. Operations are provided to apply, add, or remove
font styles to a range of the text. TextDisplay can be used with both
constant-width and proportionally-spaced fonts and with arbitrary geometric
transformations.
PUBLIC OPERATIONS¶
- TextDisplay()
- ~TextDisplay(boolean autosized = false)
- Create or destroy a TextDisplay. If autosized is
true, the TextDisplay will automatically grow its size as text is
added. The default is to keep the size constant.
- void LineHeight(Coord lineheight)
- void TabWidth(Coord tabwidth)
- Lines of text will be positioned with baselines separated
by lineheight. Tab characters in the text will cause the following
character to be positioned an integral multiple of tabwidth from
the beginning of the line.
- void Resize(Coord xmin, Coord ymin, Coord xmax, Coord
ymax)
- void Bounds(Coord& xmin, Coord& ymin, Coord&
xmax, Coord& ymax)
- Specify or query the size of the display. Only lines of
text that fall completely inside the specified region will be displayed.
TextDisplay will not draw on any part of the canvas outside the specified
bounds. Conversely, TextDisplay is free to draw on any part of the canvas
within the specified bounds.
- void Draw(Painter*, Canvas*)
- Specify the painter and canvas to use for drawing
operations; the painter specifies the font, colors, and geometric
transformation. Draw should be called before performing any operation on
the TextDisplay which produces output or requires graphical information,
or when there is a possibility that the painter or canvas has changed
since the function was last called.
- void Redraw(Coord left, Coord bottom, Coord right, Coord
top)
- Redraw a specified region of the display.
- void Scroll(int line, Coord x, Coord y)
- Scroll the display so that line line is positioned
with its upper-left corner at ( x, y). There are no
restrictions on the arguments: it is possible to scroll the display so
that no lines are visible.
- void InsertLinesAfter(int line, int count)
- void InsertLinesBefore(int line, int count)
- void DeleteLinesAfter(int line, int count)
- void DeleteLinesBefore(int line, int count)
- Insert or delete whole lines of text. Line line is
not affected by the operation. Other lines will move up or down to
accommodate the changes. Newly inserted lines are blank. The specified
line need not refer to an existing line.
- void InsertText(int line, int index, const char*, int
count)
- void DeleteText(int line, int index, int count)
- void ReplaceText(int line, const char*, int
count)
- Modify the text within line line. InsertText and
DeleteText will cause the following characters on the line to move to
accommodate the changes. ReplaceText replaces the entire text of the line.
If the specified line is non-existent, a new line will be created.
- void Style(int line1, int index1, int line2, int index2,
int style)
- void AddStyle(int line1, int index1, int line2, int
index2, int style)
- void RemoveStyle(int line1, int index1, int line2, int
index2, int style)
- Modify the styling of a range of text. Style replaces any
existing style; AddStyle adds style style in addition to any
existing styles; RemoveStyle removes style style without affecting
other existing styles. Styles are specified as any combination of the
constants Plain, Boldface, Underlined, and Reversed.
- void CaretStyle(int style)
- void Caret(int line, int index)
- Control the shape and position of a caret. Valid caret
styles are currently NoCaret, BarCaret, UnderscoreCaret and OutlineCaret.
TextDisplay does not automatically adjust the position of the caret
following insertions and deletions.
- int LineNumber(Coord y)
- int LineIndex(int line, Coord x)
- Map x and y display coordinates into line and index text
coordinates. LineNumber returns the number of the line that contains the
specified vertical position y. LineIndex returns the index into
line line that best corresponds to the specified horizontal
position x.
- Coord Width()
- Coord Height()
- Return the width or the height of the text currently
displayed by the TextDisplay. Width returns the width of the longest line
in the display. Height returns the distance from the top of the topmost
line to the bottom of the bottommost line. Note that these dimensions do
not necessarily correspond to the TextDisplay's bounds as returned by
Bounds.
- Coord Base(int line)
- Coord Top(int line)
- Coord Left(int line, int index)
- Coord Right(int line, int index)
- Map line and index text coordinates into x and y display
coordinates. The return values define a bounding box for the character
specified by line and index.
SEE ALSO¶
Painter(2I), Canvas(2I)