FLTK 1.3.0
Fl_Text_Display Class Reference

Rich text display widget. More...

#include <Fl_Text_Display.H>

Inheritance diagram for Fl_Text_Display:
Fl_Group Fl_Widget Fl_Text_Editor

List of all members.

Classes

struct  Style_Table_Entry
 This structure associates the color, font, andsize of a string to draw with an attribute mask matching attr. More...

Public Types

enum  {
  NORMAL_CURSOR, CARET_CURSOR, DIM_CURSOR, BLOCK_CURSOR,
  HEAVY_CURSOR
}
 text display cursor shapes enumeration More...
enum  { CURSOR_POS, CHARACTER_POS }
 the character position is the left edge of a character, whereas the cursor is thought to be between the centers of two consecutive characters.
enum  {
  DRAG_NONE = -2, DRAG_START_DND = -1, DRAG_CHAR = 0, DRAG_WORD = 1,
  DRAG_LINE = 2
}
 drag types - they match Fl::event_clicks() so that single clicking to start a collection selects by character, double clicking selects by word and triple clicking selects by line.
enum  { WRAP_NONE, WRAP_AT_COLUMN, WRAP_AT_PIXEL, WRAP_AT_BOUNDS }
 wrap types - used in wrap_mode() More...
typedef void(* Unfinished_Style_Cb )(int, void *)

Public Member Functions

void buffer (Fl_Text_Buffer *buf)
 Attach a text buffer to display, replacing the current buffer (if any)
void buffer (Fl_Text_Buffer &buf)
 Sets the current text buffer associated with the text widget.
Fl_Text_Bufferbuffer () const
 Gets the current text buffer associated with the text widget.
double col_to_x (double col) const
 Convert a column number into an x pixel position.
int count_lines (int start, int end, bool start_pos_is_line_start) const
 Count the number of lines between two positions.
Fl_Color cursor_color () const
 Gets the text cursor color.
void cursor_color (Fl_Color n)
 Sets the text cursor color.
void cursor_style (int style)
 Sets the text cursor style.
 Fl_Text_Display (int X, int Y, int W, int H, const char *l=0)
 Creates a new text display widget.
virtual int handle (int e)
 Event handling.
void hide_cursor ()
 Hides the text cursor.
void highlight_data (Fl_Text_Buffer *styleBuffer, const Style_Table_Entry *styleTable, int nStyles, char unfinishedStyle, Unfinished_Style_Cb unfinishedHighlightCB, void *cbArg)
 Attach (or remove) highlight information in text display and redisplay.
int in_selection (int x, int y) const
 Check if a pixel position is within the primary selection.
void insert (const char *text)
 Inserts "text" at the current cursor location.
void insert_position (int newPos)
 Sets the position of the text insertion cursor for text display.
int insert_position () const
 Gets the position of the text insertion cursor for text display.
int line_end (int startPos, bool startPosIsLineStart) const
 Returns the end of a line.
int line_start (int pos) const
 Return the beginning of a line.
int move_down ()
 Moves the current insert position down one line.
int move_left ()
 Moves the current insert position left one character.
int move_right ()
 Moves the current insert position right one character.
int move_up ()
 Moves the current insert position up one line.
void next_word (void)
 Moves the current insert position right one word.
void overstrike (const char *text)
 Replaces text at the current insert position.
int position_style (int lineStartPos, int lineLen, int lineIndex) const
 Find the correct style for a character.
int position_to_xy (int pos, int *x, int *y) const
 Convert a character index into a pixel position.
void previous_word (void)
 Moves the current insert position left one word.
void redisplay_range (int start, int end)
 Marks text from start to end as needing a redraw.
virtual void resize (int X, int Y, int W, int H)
 Change the size of the displayed text area.
int rewind_lines (int startPos, int nLines)
 Skip a number of lines back.
void scroll (int topLineNum, int horizOffset)
 Scrolls the current buffer to start at the specified line and column.
Fl_Align scrollbar_align () const
 Gets the scrollbar alignment type.
void scrollbar_align (Fl_Align a)
 Sets the scrollbar alignment type.
int scrollbar_width () const
 Gets the width/height of the scrollbars.
void scrollbar_width (int W)
 Sets the width/height of the scrollbars.
int shortcut () const
void shortcut (int s)
void show_cursor (int b=1)
 Shows the text cursor.
void show_insert_position ()
 Scrolls the text buffer to show the current insert position.
int skip_lines (int startPos, int nLines, bool startPosIsLineStart)
 Skip a number of lines forward.
Fl_Color textcolor () const
 Gets the default color of text in the widget.
void textcolor (Fl_Color n)
 Sets the default color of text in the widget.
Fl_Font textfont () const
 Gets the default font used when drawing text in the widget.
void textfont (Fl_Font s)
 Sets the default font used when drawing text in the widget.
Fl_Fontsize textsize () const
 Gets the default size of text in the widget.
void textsize (Fl_Fontsize s)
 Sets the default size of text in the widget.
int word_end (int pos) const
 Moves the insert position to the end of the current word.
int word_start (int pos) const
 Moves the insert position to the beginning of the current word.
void wrap_mode (int wrap, int wrap_margin)
 Set the new text wrap mode.
int wrapped_column (int row, int column) const
 Nobody knows what this function does.
int wrapped_row (int row) const
 Nobody knows what this function does.
double x_to_col (double x) const
 Convert an x pixel position into a column number.
 ~Fl_Text_Display ()
 Free a text display and release its associated memory.

Protected Types

enum  { DRAW_LINE, FIND_INDEX, FIND_INDEX_FROM_ZERO, GET_WIDTH }

Protected Member Functions

void absolute_top_line_number (int oldFirstChar)
 Line numbering stuff, currently unused.
void calc_last_char ()
 Update last display character index.
void calc_line_starts (int startLine, int endLine)
 Update the line start arrays.
void clear_rect (int style, int x, int y, int width, int height) const
 Clear a rectangle with the appropriate background color for style.
void display_insert ()
 Scroll the display to bring insertion cursor into view.
virtual void draw ()
 Draw the widget.
void draw_cursor (int, int)
 Draw a cursor with top center at X, Y.
void draw_line_numbers (bool clearAll)
 Refresh the line number area.
void draw_range (int start, int end)
 Draw a range of text.
void draw_string (int style, int x, int y, int toX, const char *string, int nChars) const
 Draw a text segment in a single style.
void draw_text (int X, int Y, int W, int H)
 Refresh a rectangle of the text display.
void draw_vline (int visLineNum, int leftClip, int rightClip, int leftCharIndex, int rightCharIndex)
 Draw a single line of text.
int empty_vlines () const
 Return true if there are lines visible with no corresponding buffer text.
void extend_range_for_styles (int *start, int *end)
 I don't know what this does!
void find_line_end (int pos, bool start_pos_is_line_start, int *lineEnd, int *nextLineStart) const
 Finds both the end of the current line and the start of the next line.
void find_wrap_range (const char *deletedText, int pos, int nInserted, int nDeleted, int *modRangeStart, int *modRangeEnd, int *linesInserted, int *linesDeleted)
 Wrapping calculations.
int find_x (const char *s, int len, int style, int x) const
 Find the index of the character that lies at the given x position.
int get_absolute_top_line_number () const
 Line numbering stuff, currently unused.
int handle_vline (int mode, int lineStart, int lineLen, int leftChar, int rightChar, int topClip, int bottomClip, int leftClip, int rightClip) const
 Universal pixel machine.
int longest_vline () const
 Find the longest line of all visible lines.
void maintain_absolute_top_line_number (int state)
 Line numbering stuff, currently unused.
int maintaining_absolute_top_line_number () const
 Line numbering stuff, currently unused.
void measure_deleted_lines (int pos, int nDeleted)
 Wrapping calculations.
double measure_proportional_character (const char *s, int colNum, int pos) const
 Wrapping calculations.
int measure_vline (int visLineNum) const
 Returns the width in pixels of the displayed line pointed to by "visLineNum".
void offset_line_starts (int newTopLineNum)
 Offset line start counters for a new vertical scroll position.
int position_to_line (int pos, int *lineNum) const
 Convert a position index into a line number offset.
int position_to_linecol (int pos, int *lineNum, int *column) const
 Find the line and column number of position pos.
void reset_absolute_top_line_number ()
 Line numbering stuff, probably unused.
int scroll_ (int topLineNum, int horizOffset)
 Scrolls the current buffer to start at the specified line and column.
double string_width (const char *string, int length, int style) const
 Find the width of a string in the font of a particular style.
void update_h_scrollbar ()
 Update vertical scrollbar.
void update_line_starts (int pos, int charsInserted, int charsDeleted, int linesInserted, int linesDeleted, int *scrolled)
 Update line start arrays and variables.
void update_v_scrollbar ()
 Update vertical scrollbar.
int vline_length (int visLineNum) const
 Count number of bytes in a visible line.
int wrap_uses_character (int lineEndPos) const
 Check if the line break is caused by a \n or by line wrapping.
void wrapped_line_counter (Fl_Text_Buffer *buf, int startPos, int maxPos, int maxLines, bool startPosIsLineStart, int styleBufOffset, int *retPos, int *retLines, int *retLineStart, int *retLineEnd, bool countLastLineMissingNewLine=true) const
 Wrapping calculations.
int xy_to_position (int x, int y, int PosType=CHARACTER_POS) const
 Translate a pixel position into a character index.
void xy_to_rowcol (int x, int y, int *row, int *column, int PosType=CHARACTER_POS) const
 Translate pixel coordinates into row and column.

Static Protected Member Functions

static void buffer_modified_cb (int pos, int nInserted, int nDeleted, int nRestyled, const char *deletedText, void *cbArg)
 This is called whenever the buffer is modified.
static void buffer_predelete_cb (int pos, int nDeleted, void *cbArg)
 This is called before any characters are deleted.
static void h_scrollbar_cb (Fl_Scrollbar *w, Fl_Text_Display *d)
 Callbacks for drag or valueChanged on scrollbars.
static void scroll_timer_cb (void *)
 Timer callback for scroll events.
static void v_scrollbar_cb (Fl_Scrollbar *w, Fl_Text_Display *d)
 Callbacks for drag or valueChanged on scrollbars.

Protected Attributes

int damage_range1_end
int damage_range1_start
int damage_range2_end
int damage_range2_start
int display_insert_position_hint
int dragging
int dragPos
int dragType
int mAbsTopLineNum
Fl_Text_BuffermBuffer
double mColumnScale
int mContinuousWrap
Fl_Color mCursor_color
int mCursorOldY
int mCursorOn
int mCursorPos
int mCursorPreferredXPos
int mCursorStyle
int mCursorToHint
int mFirstChar
void * mHighlightCBArg
int mHorizOffset
int mHorizOffsetHint
Fl_ScrollbarmHScrollBar
int mLastChar
int mLineNumLeft
int mLineNumWidth
int * mLineStarts
int mMaxsize
int mModifyingTabDistance
int mNBufferLines
int mNeedAbsTopLineNum
int mNLinesDeleted
int mNStyles
int mNVisibleLines
Fl_Text_BuffermStyleBuffer
const Style_Table_EntrymStyleTable
int mSuppressResync
int mTopLineNum
int mTopLineNumHint
Unfinished_Style_Cb mUnfinishedHighlightCB
char mUnfinishedStyle
Fl_ScrollbarmVScrollBar
int mWrapMarginPix
Fl_Align scrollbar_align_
int scrollbar_width_
int shortcut_
struct {
   int   h
   int   w
   int   x
   int   y
text_area
Fl_Color textcolor_
Fl_Font textfont_
Fl_Fontsize textsize_

Friends

void fl_text_drag_me (int pos, Fl_Text_Display *d)

Detailed Description

Rich text display widget.

This is the FLTK text display widget. It allows the user to view multiple lines of text and supports highlighting and scrolling. The buffer that is displayed in the widget is managed by the Fl_Text_Buffer class. A single Text Buffer can be displayed by multiple Text Displays.


Member Enumeration Documentation

anonymous enum

text display cursor shapes enumeration

Enumerator:
NORMAL_CURSOR 

I-beam.

CARET_CURSOR 

caret under the text

DIM_CURSOR 

dim I-beam

BLOCK_CURSOR 

unfille box under the current character

HEAVY_CURSOR 

thick I-beam

anonymous enum

wrap types - used in wrap_mode()

Enumerator:
WRAP_NONE 

don't wrap text at all

WRAP_AT_COLUMN 

wrap text at the given text column

WRAP_AT_PIXEL 

wrap text at a pixel position

WRAP_AT_BOUNDS 

wrap text so that it fits into the widget width


Constructor & Destructor Documentation

Fl_Text_Display::Fl_Text_Display ( int  X,
int  Y,
int  W,
int  H,
const char *  l = 0 
)

Creates a new text display widget.

Parameters:
X,Y,W,Hposition and size of widget
llabel text, defaults to none

Free a text display and release its associated memory.

Note, the text BUFFER that the text display displays is a separate entity and is not freed, nor are the style buffer or style table.


Member Function Documentation

void Fl_Text_Display::absolute_top_line_number ( int  oldFirstChar) [protected]

Line numbering stuff, currently unused.

Re-calculate absolute top line number for a change in scroll position.

Attach a text buffer to display, replacing the current buffer (if any)

Parameters:
bufattach this text buffer
void Fl_Text_Display::buffer ( Fl_Text_Buffer buf) [inline]

Sets the current text buffer associated with the text widget.

Multiple text widgets can be associated with the same text buffer.

Parameters:
bufnew text buffer

Gets the current text buffer associated with the text widget.

Multiple text widgets can be associated with the same text buffer.

Returns:
current text buffer
void Fl_Text_Display::buffer_modified_cb ( int  pos,
int  nInserted,
int  nDeleted,
int  nRestyled,
const char *  deletedText,
void *  cbArg 
) [static, protected]

This is called whenever the buffer is modified.

Callback attached to the text buffer to receive modification information

Parameters:
posstarting index of modification
nInsertednumber of bytes we inserted (must be UTF-8 aligned!)
nDeletednumber of bytes deleted (must be UTF-8 aligned!)
nRestyled??
deletedTextthis is what was removed, must not be NULL if nDeleted is set
cbArg"this" pointer for static callback function
void Fl_Text_Display::buffer_predelete_cb ( int  pos,
int  nDeleted,
void *  cbArg 
) [static, protected]

This is called before any characters are deleted.

Callback attached to the text buffer to receive delete information before the modifications are actually made.

Parameters:
posstarting index of deletion
nDeletednumber of bytes we will delete (must be UTF-8 aligned!)
cbArg"this" pointer for static callback function
void Fl_Text_Display::calc_last_char ( ) [protected]

Update last display character index.

Given a Fl_Text_Display with a complete, up-to-date lineStarts array, update the lastChar entry to point to the last buffer position displayed.

void Fl_Text_Display::calc_line_starts ( int  startLine,
int  endLine 
) [protected]

Update the line start arrays.

Scan through the text in the "textD"'s buffer and recalculate the line starts array values beginning at index "startLine" and continuing through (including) "endLine". It assumes that the line starts entry preceding "startLine" (or mFirstChar if startLine is 0) is good, and re-counts newlines to fill in the requested entries. Out of range values for "startLine" and "endLine" are acceptable.

Parameters:
startLine,endLinerange of lines to scan as line numbers
void Fl_Text_Display::clear_rect ( int  style,
int  X,
int  Y,
int  width,
int  height 
) const [protected]

Clear a rectangle with the appropriate background color for style.

Parameters:
styleindex into style table
X,Y,width,heightsize and position of background area
double Fl_Text_Display::col_to_x ( double  col) const

Convert a column number into an x pixel position.

Parameters:
colan approximate column number based on the main font
Returns:
number of pixels from the left margin to the left of an average sized character
int Fl_Text_Display::count_lines ( int  startPos,
int  endPos,
bool  startPosIsLineStart 
) const

Count the number of lines between two positions.

Same as BufCountLines, but takes into account wrapping if wrapping is turned on. If the caller knows that startPos is at a line start, it can pass startPosIsLineStart as True to make the call more efficient by avoiding the additional step of scanning back to the last newline.

Parameters:
startPosindex to first character
endPosindex after last character
startPosIsLineStartavoid scanning back to the line start
Returns:
number of lines

Gets the text cursor color.

Returns:
cursor color

Sets the text cursor color.

Parameters:
nnew cursor color
void Fl_Text_Display::cursor_style ( int  style)

Sets the text cursor style.

Sets the text cursor style to one of the following:

This call also switches the cursor on and may trigger a redraw.

Parameters:
stylenew cursor style
void Fl_Text_Display::display_insert ( ) [protected]

Scroll the display to bring insertion cursor into view.

Note: it would be nice to be able to do this without counting lines twice (scroll_() counts them too) and/or to count from the most efficient starting point, but the efficiency of this routine is not as important to the overall performance of the text display.

Todo:
Unicode?
void Fl_Text_Display::draw ( void  ) [protected, virtual]

Draw the widget.

This function tries to limit drawing to smaller areas if possible.

Reimplemented from Fl_Group.

void Fl_Text_Display::draw_cursor ( int  X,
int  Y 
) [protected]

Draw a cursor with top center at X, Y.

Parameters:
X,Ycursor position in pixels
void Fl_Text_Display::draw_line_numbers ( bool  clearAll) [protected]

Refresh the line number area.

If clearAll is False, writes only over the character cell areas. Setting clearAll to True will clear out any stray marks outside of the character cell area, which might have been left from before a resize or font change.

This function is not used.

void Fl_Text_Display::draw_range ( int  startpos,
int  endpos 
) [protected]

Draw a range of text.

Refresh all of the text between buffer positions startpos and endpos not including the character at the position endpos.

If endpos points beyond the end of the buffer, refresh the whole display after startpos, including blank lines which are not technically part of any range of characters.

Parameters:
startposindex of first character to draw
endposindex after last character to draw
void Fl_Text_Display::draw_string ( int  style,
int  X,
int  Y,
int  toX,
const char *  string,
int  nChars 
) const [protected]

Draw a text segment in a single style.

Draw a string or blank area according to parameter style, using the appropriate colors and drawing method for that style, with top left corner at X, Y. If style says to draw text, use string as source of characters, and draw nChars, if style is FILL, erase rectangle where text would have drawn from X to toX and from Y to the maximum y extent of the current font(s).

Parameters:
styleindex into style lookup table
X,Ydrawing origin
toXrightmost position if this is a fill operation
stringtext if this is a drawing operation
nCharsnumber of characters to draw
void Fl_Text_Display::draw_text ( int  left,
int  top,
int  width,
int  height 
) [protected]

Refresh a rectangle of the text display.

Parameters:
left,topare in coordinates of the text drawing window.
width,heightsize in pixels
void Fl_Text_Display::draw_vline ( int  visLineNum,
int  leftClip,
int  rightClip,
int  leftCharIndex,
int  rightCharIndex 
) [protected]

Draw a single line of text.

Draw the text on a single line represented by visLineNum (the number of lines down from the top of the display), limited by leftClip and rightClip window coordinates and leftCharIndex and rightCharIndex character positions (not including the character at position rightCharIndex).

Parameters:
visLineNumindex of line in the visible line number lookup
leftClip,rightClippixel position of clipped area
leftCharIndex,rightCharIndexindex into line of segment that we want to draw
int Fl_Text_Display::empty_vlines ( ) const [protected]

Return true if there are lines visible with no corresponding buffer text.

Returns:
1 if there are empty lines
void Fl_Text_Display::extend_range_for_styles ( int *  startpos,
int *  endpos 
) [protected]

I don't know what this does!

Extend the range of a redraw request (from *start to *end) with additional redraw requests resulting from changes to the attached style buffer (which contains auxiliary information for coloring or styling text).

Parameters:
startpos??
endpos??
Todo:
Unicode?
void Fl_Text_Display::find_line_end ( int  startPos,
bool  startPosIsLineStart,
int *  lineEnd,
int *  nextLineStart 
) const [protected]

Finds both the end of the current line and the start of the next line.

Why? In continuous wrap mode, if you need to know both, figuring out one from the other can be expensive or error prone. The problem comes when there's a trailing space or tab just before the end of the buffer. To translate an end of line value to or from the next lines start value, you need to know whether the trailing space or tab is being used as a line break or just a normal character, and to find that out would otherwise require counting all the way back to the beginning of the line.

Parameters:
startPos
startPosIsLineStart
[out]lineEnd
[out]nextLineStart
void Fl_Text_Display::find_wrap_range ( const char *  deletedText,
int  pos,
int  nInserted,
int  nDeleted,
int *  modRangeStart,
int *  modRangeEnd,
int *  linesInserted,
int *  linesDeleted 
) [protected]

Wrapping calculations.

When continuous wrap is on, and the user inserts or deletes characters, wrapping can happen before and beyond the changed position. This routine finds the extent of the changes, and counts the deleted and inserted lines over that range. It also attempts to minimize the size of the range to what has to be counted and re-displayed, so the results can be useful both for delimiting where the line starts need to be recalculated, and for deciding what part of the text to redisplay.

Parameters:
deletedText
pos
nInserted
nDeleted
modRangeStart
modRangeEnd
linesInserted
linesDeleted
int Fl_Text_Display::find_x ( const char *  s,
int  len,
int  style,
int  x 
) const [protected]

Find the index of the character that lies at the given x position.

Parameters:
sUTF-8 text string
lenlength of string
styleindex into style lookup table
xposition in pixels
Returns:
index into buffer

Line numbering stuff, currently unused.

Returns the absolute (non-wrapped) line number of the first line displayed. Returns 0 if the absolute top line number is not being maintained.

int Fl_Text_Display::handle_vline ( int  mode,
int  lineStartPos,
int  lineLen,
int  leftChar,
int  rightChar,
int  Y,
int  bottomClip,
int  leftClip,
int  rightClip 
) const [protected]

Universal pixel machine.

We use a single function that handles all line layout, measuring, and drawing

  • draw a text range
  • return the width of a text range in pixels
  • return the index of a character that is at a pixel position
Parameters:
[in]modeDRAW_LINE, GET_WIDTH, FIND_INDEX
[in]lineStartPosindex of first character
[in]lineLensize of string in bytes
[in]leftChar,rightChar
[in]Ydrawing position
[in]bottomClip,leftClip,rightClipstop work when we reach the clipped area. rightClip is the X position that we search in FIND_INDEX.
Return values:
DRAW_LINEindex of last drawn character
GET_WIDTHwidth in pixels of text segment if we would draw it
FIND_INDEXindex of character at given x position in window coordinates
FIND_INDEX_FROM_ZEROindex of character at given x position without scrolling and widget offsets
Todo:

we need to handle hidden hyphens and tabs here!

we handle all styles and selections

we must provide code to get pixel positions of the middle of a character as well

void Fl_Text_Display::highlight_data ( Fl_Text_Buffer styleBuffer,
const Style_Table_Entry styleTable,
int  nStyles,
char  unfinishedStyle,
Unfinished_Style_Cb  unfinishedHighlightCB,
void *  cbArg 
)

Attach (or remove) highlight information in text display and redisplay.

Highlighting information consists of a style buffer which parallels the normal text buffer, but codes font and color information for the display; a style table which translates style buffer codes (indexed by buffer character - 'A') into fonts and colors; and a callback mechanism for as-needed highlighting, triggered by a style buffer entry of "unfinishedStyle". Style buffer can trigger additional redisplay during a normal buffer modification if the buffer contains a primary Fl_Text_Selection (see extendRangeForStyleMods for more information on this protocol).

Style buffers, tables and their associated memory are managed by the caller.

Styles are ranged from 65 ('A') to 126.

Parameters:
styleBufferthis buffer works in parallel to the text buffer. For every character in the text buffer, the stye buffer has a byte at the same offset that contains an index into an array of possible styles.
styleTablea list of styles indexed by the style buffer
nStylesnumber of styles in the style table
unfinishedStyleif this style is found, the callback below is called
unfinishedHighlightCBif a character with an unfinished style is found, this callback will be called
cbArgand optional argument for the callback above, usually a pointer to the Text Display.
int Fl_Text_Display::in_selection ( int  X,
int  Y 
) const

Check if a pixel position is within the primary selection.

Parameters:
X,Ypixel position to test
Returns:
1 if position (X, Y) is inside of the primary Fl_Text_Selection
void Fl_Text_Display::insert ( const char *  text)

Inserts "text" at the current cursor location.

This has the same effect as inserting the text into the buffer using BufInsert and then moving the insert position after the newly inserted text, except that it's optimized to do less redrawing.

Parameters:
textnew text in UTF-8 encoding.
void Fl_Text_Display::insert_position ( int  newPos)

Sets the position of the text insertion cursor for text display.

Move the insertion cursor in front of the character at newPos. This function may trigger a redraw.

Parameters:
newPosnew caret position
int Fl_Text_Display::insert_position ( ) const [inline]

Gets the position of the text insertion cursor for text display.

Returns:
insert position index into text buffer
int Fl_Text_Display::line_end ( int  startPos,
bool  startPosIsLineStart 
) const

Returns the end of a line.

Same as BufEndOfLine, but takes into account line breaks when wrapping is turned on. If the caller knows that startPos is at a line start, it can pass "startPosIsLineStart" as True to make the call more efficient by avoiding the additional step of scanning back to the last newline.

Note that the definition of the end of a line is less clear when continuous wrap is on. With continuous wrap off, it's just a pointer to the newline that ends the line. When it's on, it's the character beyond the last displayable character on the line, where a whitespace character which has been "converted" to a newline for wrapping is not considered displayable. Also note that a line can be wrapped at a non-whitespace character if the line had no whitespace. In this case, this routine returns a pointer to the start of the next line. This is also consistent with the model used by visLineLength.

Parameters:
startPosindex to starting character
startPosIsLineStartavoid scanning back to the line start
Returns:
new position as index
int Fl_Text_Display::line_start ( int  pos) const

Return the beginning of a line.

Same as BufStartOfLine, but returns the character after last wrap point rather than the last newline.

Parameters:
posindex to starting character
Returns:
new position as index
int Fl_Text_Display::longest_vline ( ) const [protected]

Find the longest line of all visible lines.

Returns:
the width of the longest visible line in pixels
void Fl_Text_Display::maintain_absolute_top_line_number ( int  state) [protected]

Line numbering stuff, currently unused.

In continuous wrap mode, internal line numbers are calculated after wrapping. A separate non-wrapped line count is maintained when line numbering is turned on. There is some performance cost to maintaining this line count, so normally absolute line numbers are not tracked if line numbering is off. This routine allows callers to specify that they still want this line count maintained (for use via TextDPosToLineAndCol). More specifically, this allows the line number reported in the statistics line to be calibrated in absolute lines, rather than post-wrapped lines.

Line numbering stuff, currently unused.

Return true if a separate absolute top line number is being maintained (for displaying line numbers or showing in the statistics line).

void Fl_Text_Display::measure_deleted_lines ( int  pos,
int  nDeleted 
) [protected]

Wrapping calculations.

This is a stripped-down version of the findWrapRange() function above, intended to be used to calculate the number of "deleted" lines during a buffer modification. It is called _before_ the modification takes place.

This function should only be called in continuous wrap mode with a non-fixed font width. In that case, it is impossible to calculate the number of deleted lines, because the necessary style information is no longer available _after_ the modification. In other cases, we can still perform the calculation afterwards (possibly even more efficiently).

Parameters:
pos
nDeleted
double Fl_Text_Display::measure_proportional_character ( const char *  s,
int  xPix,
int  pos 
) const [protected]

Wrapping calculations.

Measure the width in pixels of the first character of string "s" at a particular column "colNum" and buffer position "pos". This is for measuring characters in proportional or mixed-width highlighting fonts.

A note about proportional and mixed-width fonts: the mixed width and proportional font code in nedit does not get much use in general editing, because nedit doesn't allow per-language-mode fonts, and editing programs in a proportional font is usually a bad idea, so very few users would choose a proportional font as a default. There are still probably mixed- width syntax highlighting cases where things don't redraw properly for insertion/deletion, though static display and wrapping and resizing should now be solid because they are now used for online help display.

Parameters:
stext string
xPixx pixel position needed for calculating tab widths
posoffset within string
Returns:
width of character in pixels
int Fl_Text_Display::measure_vline ( int  visLineNum) const [protected]

Returns the width in pixels of the displayed line pointed to by "visLineNum".

Parameters:
visLineNumindex into visible lines array
Returns:
width of line in pixels

Moves the current insert position down one line.

Returns:
1 if the cursor moved, 0 if the beginning of the text was reached

Moves the current insert position left one character.

Returns:
1 if the cursor moved, 0 if the beginning of the text was reached

Moves the current insert position right one character.

Returns:
1 if the cursor moved, 0 if the end of the text was reached

Moves the current insert position up one line.

Returns:
1 if the cursor moved, 0 if the beginning of the text was reached
void Fl_Text_Display::offset_line_starts ( int  newTopLineNum) [protected]

Offset line start counters for a new vertical scroll position.

Offset the line starts array, mTopLineNum, mFirstChar and lastChar, for a new vertical scroll position given by newTopLineNum. If any currently displayed lines will still be visible, salvage the line starts values, otherwise, count lines from the nearest known line start (start or end of buffer, or the closest value in the mLineStarts array)

Parameters:
newTopLineNumindex into buffer
void Fl_Text_Display::overstrike ( const char *  text)

Replaces text at the current insert position.

Parameters:
textnew text in UTF-8 encoding
Todo:
Unicode? Find out exactly what we do here and simplify.
int Fl_Text_Display::position_style ( int  lineStartPos,
int  lineLen,
int  lineIndex 
) const

Find the correct style for a character.

Determine the drawing method to use to draw a specific character from "buf". lineStartPos gives the character index where the line begins, lineIndex, the number of characters past the beginning of the line, and lineIndex the number of displayed characters past the beginning of the line. Passing lineStartPos of -1 returns the drawing style for "no text".

Why not just: position_style(pos)? Because style applies to blank areas of the window beyond the text boundaries, and because this routine must also decide whether a position is inside of a rectangular Fl_Text_Selection, and do so efficiently, without re-counting character positions from the start of the line.

Note that style is a somewhat incorrect name, drawing method would be more appropriate.

Parameters:
lineStartPosbeginning of this line
lineLennumber of bytes in line
lineIndexposition of character within line
Returns:
style for the given character
int Fl_Text_Display::position_to_line ( int  pos,
int *  lineNum 
) const [protected]

Convert a position index into a line number offset.

Find the line number of position pos relative to the first line of displayed text. Returns 0 if the line is not displayed.

Parameters:
pos??
[out]lineNum??
Returns:
??
Todo:
What does this do?
int Fl_Text_Display::position_to_linecol ( int  pos,
int *  lineNum,
int *  column 
) const [protected]

Find the line and column number of position pos.

This only works for displayed lines. If the line is not displayed, the function returns 0 (without the mLineStarts array it could turn in to very long calculation involving scanning large amounts of text in the buffer). If continuous wrap mode is on, returns the absolute line number (as opposed to the wrapped line number which is used for scrolling).

Parameters:
poscharacter index
[out]lineNumabsolute (unwrapped) line number
[out]columncharacter offset to the beginning of the line
Returns:
0 if pos is off screen, line number otherwise
Todo:
a column number makes little sense in the UTF-8/variable font width environment. We will have to further define what exactly we want to return. Please check the functions that call this particular function.
int Fl_Text_Display::position_to_xy ( int  pos,
int *  X,
int *  Y 
) const

Convert a character index into a pixel position.

Translate a buffer text position to the XY location where the top left of the cursor would be positioned to point to that character. Returns 0 if the position is not displayed because it is vertically out of view. If the position is horizontally out of view, returns the X coordinate where the position would be if it were visible.

Parameters:
poscharacter index
[out]X,Ypixel position of character on screen
Returns:
0 if character vertically out of view, X position otherwise
void Fl_Text_Display::redisplay_range ( int  startpos,
int  endpos 
)

Marks text from start to end as needing a redraw.

This function will trigger a damage event and later a redraw of parts of the widget.

Parameters:
startposindex of first character needing redraw
endposindex after last character needing redraw

Line numbering stuff, probably unused.

Count lines from the beginning of the buffer to reestablish the absolute (non-wrapped) top line number. If mode is not continuous wrap, or the number is not being maintained, does nothing.

void Fl_Text_Display::resize ( int  X,
int  Y,
int  W,
int  H 
) [virtual]

Change the size of the displayed text area.

Calling this function will trigger a recalculation of all lines visible and of all scrollbar sizes.

Parameters:
X,Y,W,Hnew position and size of this widget

Reimplemented from Fl_Group.

int Fl_Text_Display::rewind_lines ( int  startPos,
int  nLines 
)

Skip a number of lines back.

Same as BufCountBackwardNLines, but takes into account line breaks when wrapping is turned on.

Parameters:
startPosindex to starting character
nLinesnumber of lines to skip back
Returns:
new position as index
void Fl_Text_Display::scroll ( int  topLineNum,
int  horizOffset 
)

Scrolls the current buffer to start at the specified line and column.

Parameters:
topLineNumtop line number
horizOffsetcolumn number
Todo:
Column numbers make little sense here.
int Fl_Text_Display::scroll_ ( int  topLineNum,
int  horizOffset 
) [protected]

Scrolls the current buffer to start at the specified line and column.

Parameters:
topLineNumtop line number
horizOffsetin pixels
Returns:
0 if nothing changed, 1 if we scrolled
void Fl_Text_Display::scroll_timer_cb ( void *  user_data) [static, protected]

Timer callback for scroll events.

This timer event scrolls the text view proportionally to how far the mouse pointer has left the text area. This allows for smooth scrolling without "wiggeling" the mouse.

Gets the scrollbar alignment type.

Returns:
scrollbar alignment

Sets the scrollbar alignment type.

Parameters:
anew scrollbar alignment
int Fl_Text_Display::scrollbar_width ( ) const [inline]

Gets the width/height of the scrollbars.

/return width of scrollbars

void Fl_Text_Display::scrollbar_width ( int  W) [inline]

Sets the width/height of the scrollbars.

Parameters:
Wwidth of scrollbars
int Fl_Text_Display::shortcut ( ) const [inline]
Todo:
FIXME : get set methods pointing on shortcut_ have no effects as shortcut_ is unused in this class and derived!
Returns:
the current shortcut key
void Fl_Text_Display::shortcut ( int  s) [inline]
Todo:
FIXME : get set methods pointing on shortcut_ have no effects as shortcut_ is unused in this class and derived!
Parameters:
sthe new shortcut key
void Fl_Text_Display::show_cursor ( int  b = 1)

Shows the text cursor.

This function may trigger a redraw.

Parameters:
bshow(1) or hide(0) the text cursor (caret).

Scrolls the text buffer to show the current insert position.

This function triggers a complete recalculation, ending in a call to Fl_Text_Display::display_insert()

int Fl_Text_Display::skip_lines ( int  startPos,
int  nLines,
bool  startPosIsLineStart 
)

Skip a number of lines forward.

Same as BufCountForwardNLines, but takes into account line breaks when wrapping is turned on. If the caller knows that startPos is at a line start, it can pass "startPosIsLineStart" as True to make the call more efficient by avoiding the additional step of scanning back to the last newline.

Parameters:
startPosindex to starting character
nLinesnumber of lines to skip ahead
startPosIsLineStartavoid scanning back to the line start
Returns:
new position as index
double Fl_Text_Display::string_width ( const char *  string,
int  length,
int  style 
) const [protected]

Find the width of a string in the font of a particular style.

Parameters:
stringthe text
lengthnumber of bytes in string
styleindex into style table
Returns:
width of text segment in pixels

Gets the default color of text in the widget.

Returns:
text color unless overridden by a style
void Fl_Text_Display::textcolor ( Fl_Color  n) [inline]

Sets the default color of text in the widget.

Parameters:
nnew text color
Fl_Font Fl_Text_Display::textfont ( ) const [inline]

Gets the default font used when drawing text in the widget.

Returns:
current text font face unless overridden by a style
void Fl_Text_Display::textfont ( Fl_Font  s) [inline]

Sets the default font used when drawing text in the widget.

Parameters:
sdefault text font face

Gets the default size of text in the widget.

Returns:
current text height unless overridden by a style
void Fl_Text_Display::textsize ( Fl_Fontsize  s) [inline]

Sets the default size of text in the widget.

Parameters:
snew text size

Update vertical scrollbar.

Update the minimum, maximum, slider size, page increment, and value for the horizontal scrollbar.

void Fl_Text_Display::update_line_starts ( int  pos,
int  charsInserted,
int  charsDeleted,
int  linesInserted,
int  linesDeleted,
int *  scrolled 
) [protected]

Update line start arrays and variables.

Update the line starts array, mTopLineNum, mFirstChar and lastChar for this text display after a modification to the text buffer, given by the position pos where the change began, and the numbers of characters and lines inserted and deleted.

Parameters:
posindex into buffer of recent changes
charsInsertednumber of bytes(!) inserted
charsDeletednumber of bytes(!) deleted
linesInsertednumber of lines
linesDeletednumber of lines
[out]scrolledset to 1 if the text display needs to be scrolled

Update vertical scrollbar.

Update the minimum, maximum, slider size, page increment, and value for vertical scrollbar.

int Fl_Text_Display::vline_length ( int  visLineNum) const [protected]

Count number of bytes in a visible line.

Return the length of a line (number of bytes) by examining entries in the line starts array rather than by scanning for newlines.

Parameters:
visLineNumindex of line in visible line array
Returns:
number of bytes in this line
int Fl_Text_Display::word_end ( int  pos) const [inline]

Moves the insert position to the end of the current word.

Parameters:
posstart calculation at this index
Returns:
index of first character after the end of the word
int Fl_Text_Display::word_start ( int  pos) const [inline]

Moves the insert position to the beginning of the current word.

Parameters:
posstart calculation at this index
Returns:
beginning of the words
void Fl_Text_Display::wrap_mode ( int  wrap,
int  wrapMargin 
)

Set the new text wrap mode.

If wrap mode is not zero, this call enables automatic word wrapping at column wrapMargin. Word-wrapping does not change the text buffer itself, only the way the text is displayed. Different Text Displays can have different wrap modes, even if they share the same Text Buffer.

Parameters:
wrapnew wrap mode is WRAP_NONE (don't wrap text at all), WRAP_AT_COLUMN (wrap text at the given text column), WRAP_AT_PIXEL (wrap text at a pixel position), or WRAP_AT_BOUNDS (wrap text so that it fits into the widget width)
wrapMarginin WRAP_AT_COLUMN mode, text will wrap at the n'th character. For variable width fonts, an average character width is calculated. The column width is calculated using the current textfont or the first style when this function is called. If the font size changes, this function must be called again. In WRAP_AT_PIXEL mode, this is the pixel position.
Todo:
we need new wrap modes to wrap at the window edge and based on pixel width or average character width.
int Fl_Text_Display::wrap_uses_character ( int  lineEndPos) const [protected]

Check if the line break is caused by a \n or by line wrapping.

Line breaks in continuous wrap mode usually happen at newlines or whitespace. This line-terminating character is not included in line width measurements and has a special status as a non-visible character. However, lines with no whitespace are wrapped without the benefit of a line terminating character, and this distinction causes endless trouble with all of the text display code which was originally written without continuous wrap mode and always expects to wrap at a newline character.

Given the position of the end of the line, as returned by TextDEndOfLine or BufEndOfLine, this returns true if there is a line terminating character, and false if there's not. On the last character in the buffer, this function can't tell for certain whether a trailing space was used as a wrap point, and just guesses that it wasn't. So if an exact accounting is necessary, don't use this function.

Parameters:
lineEndPosindex of character where the line wraps
Returns:
1 if a \n character causes the line wrap
int Fl_Text_Display::wrapped_column ( int  row,
int  column 
) const

Nobody knows what this function does.

Correct a column number based on an unconstrained position (as returned by TextDXYToUnconstrainedPosition) to be relative to the last actual newline in the buffer before the row and column position given, rather than the last line start created by line wrapping. This is an adapter for rectangular selections and code written before continuous wrap mode, which thinks that the unconstrained column is the number of characters from the last newline. Obviously this is time consuming, because it invloves character re-counting.

Parameters:
row
column
Returns:
something unknown
Todo:
What does this do and how is it useful? Column numbers mean little in this context. Which functions depend on this one?
Todo:
Unicode?
void Fl_Text_Display::wrapped_line_counter ( Fl_Text_Buffer buf,
int  startPos,
int  maxPos,
int  maxLines,
bool  startPosIsLineStart,
int  styleBufOffset,
int *  retPos,
int *  retLines,
int *  retLineStart,
int *  retLineEnd,
bool  countLastLineMissingNewLine = true 
) const [protected]

Wrapping calculations.

Count forward from startPos to either maxPos or maxLines (whichever is reached first), and return all relevant positions and line count. The provided textBuffer may differ from the actual text buffer of the widget. In that case it must be a (partial) copy of the actual text buffer and the styleBufOffset argument must indicate the starting position of the copy, to take into account the correct style information.

Parameters:
buf
startPos
maxPos
maxLines
startPosIsLineStart
styleBufOffset
[out]retPosPosition where counting ended. When counting lines, the position returned is the start of the line "maxLines" lines beyond "startPos".
[out]retLinesNumber of line breaks counted
[out]retLineStartStart of the line where counting ended
[out]retLineEndEnd position of the last line traversed
[out]countLastLineMissingNewLine
int Fl_Text_Display::wrapped_row ( int  row) const

Nobody knows what this function does.

Correct a row number from an unconstrained position (as returned by TextDXYToUnconstrainedPosition) to a straight number of newlines from the top line of the display. Because rectangular selections are based on newlines, rather than display wrapping, and anywhere a rectangular selection needs a row, it needs it in terms of un-wrapped lines.

Parameters:
row
Returns:
something unknown
Todo:
What does this do and how is it useful? Column numbers mean little in this context. Which functions depend on this one?
double Fl_Text_Display::x_to_col ( double  x) const

Convert an x pixel position into a column number.

Parameters:
xnumber of pixels from the left margin
Returns:
an approximate column number based on the main font
int Fl_Text_Display::xy_to_position ( int  X,
int  Y,
int  posType = CHARACTER_POS 
) const [protected]

Translate a pixel position into a character index.

Translate window coordinates to the nearest (insert cursor or character cell) text position. The parameter posType specifies how to interpret the position: CURSOR_POS means translate the coordinates to the nearest cursor position, and CHARACTER_POS means return the position of the character closest to (X, Y).

Parameters:
X,Ypixel position
posTypeCURSOR_POS or CHARACTER_POS
Returns:
index into text buffer
void Fl_Text_Display::xy_to_rowcol ( int  X,
int  Y,
int *  row,
int *  column,
int  posType = CHARACTER_POS 
) const [protected]

Translate pixel coordinates into row and column.

Translate window coordinates to the nearest row and column number for positioning the cursor. This, of course, makes no sense when the font is proportional, since there are no absolute columns. The parameter posType specifies how to interpret the position: CURSOR_POS means translate the coordinates to the nearest position between characters, and CHARACTER_POS means translate the position to the nearest character cell.

Parameters:
X,Ypixel coordinates
[out]row,columnneares row and column
posTypeCURSOR_POS or CHARACTER_POS

The documentation for this class was generated from the following files: