wine/dlls/user/text.c
Bill Medland 7d983d244a Pass information through arguments instead of static variables.
Add protection to prevent reading outside the buffer.
Better handling of degenerate cases.
2002-03-11 01:15:31 +00:00

1410 lines
48 KiB
C

/*
* USER text functions
*
* Copyright 1993, 1994 Alexandre Julliard
* Copyright 2002 Bill Medland
*
* Contains
* 1. DrawText functions
* 2. GrayString functions
* 3. TabbedText functions
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <string.h>
#include <assert.h>
#include "windef.h"
#include "wingdi.h"
#include "wine/winuser16.h"
#include "wine/unicode.h"
#include "winbase.h"
#include "winerror.h"
#include "winnls.h"
#include "user.h"
#include "wine/debug.h"
WINE_DEFAULT_DEBUG_CHANNEL(text);
/*********************************************************************
*
* DrawText functions
*
* Design issues
* How many buffers to use
* While processing in DrawText there are potentially three different forms
* of the text that need to be held. How are they best held?
* 1. The original text is needed, of course, to see what to display.
* 2. The text that will be returned to the user if the DT_MODIFYSTRING is
* in effect.
* 3. The buffered text that is about to be displayed e.g. the current line.
* Typically this will exclude the ampersands used for prefixing etc.
*
* Complications.
* a. If the buffered text to be displayed includes the ampersands then
* we will need special measurement and draw functions that will ignore
* the ampersands (e.g. by copying to a buffer without the prefix and
* then using the normal forms). This may involve less space but may
* require more processing. e.g. since a line containing tabs may
* contain several underlined characters either we need to carry around
* a list of prefix locations or we may need to locate them several
* times.
* b. If we actually directly modify the "original text" as we go then we
* will need some special "caching" to handle the fact that when we
* ellipsify the text the ellipsis may modify the next line of text,
* which we have not yet processed. (e.g. ellipsification of a W at the
* end of a line will overwrite the W, the \n and the first character of
* the next line, and a \0 will overwrite the second. Try it!!)
*
* Option 1. Three separate storages. (To be implemented)
* If DT_MODIFYSTRING is in effect then allocate an extra buffer to hold
* the edited string in some form, either as the string itself or as some
* sort of "edit list" to be applied just before returning.
* Use a buffer that holds the ellipsified current line sans ampersands
* and accept the need occasionally to recalculate the prefixes (if
* DT_EXPANDTABS and not DT_NOPREFIX and not DT_HIDEPREFIX)
*/
#define TAB 9
#define LF 10
#define CR 13
#define SPACE 32
#define PREFIX 38
#define FORWARD_SLASH '/'
#define BACK_SLASH '\\'
static const WCHAR ELLIPSISW[] = {'.','.','.', 0};
typedef struct tag_ellipsis_data
{
int before;
int len;
int under;
int after;
} ellipsis_data;
/*********************************************************************
* TEXT_Ellipsify (static)
*
* Add an ellipsis to the end of the given string whilst ensuring it fits.
*
* If the ellipsis alone doesn't fit then it will be returned anyway.
*
* See Also TEXT_PathEllipsify
*
* Arguments
* hdc [in] The handle to the DC that defines the font.
* str [in/out] The string that needs to be modified.
* max_str [in] The dimension of str (number of WCHAR).
* len_str [in/out] The number of characters in str
* width [in] The maximum width permitted (in logical coordinates)
* size [out] The dimensions of the text
* modstr [out] The modified form of the string, to be returned to the
* calling program. It is assumed that the caller has
* made sufficient space available so we don't need to
* know the size of the space. This pointer may be NULL if
* the modified string is not required.
* len_before [out] The number of characters before the ellipsis.
* len_ellip [out] The number of characters in the ellipsis.
*
* See for example Microsoft article Q249678.
*
* For now we will simply use three dots rather than worrying about whether
* the font contains an explicit ellipsis character.
*/
static void TEXT_Ellipsify (HDC hdc, WCHAR *str, unsigned int max_len,
unsigned int *len_str, int width, SIZE *size,
WCHAR *modstr,
int *len_before, int *len_ellip)
{
unsigned int len_ellipsis;
len_ellipsis = strlenW (ELLIPSISW);
if (len_ellipsis > max_len) len_ellipsis = max_len;
if (*len_str > max_len - len_ellipsis)
*len_str = max_len - len_ellipsis;
for ( ; ; )
{
strncpyW (str + *len_str, ELLIPSISW, len_ellipsis);
if (!GetTextExtentExPointW (hdc, str, *len_str + len_ellipsis, width,
NULL, NULL, size)) break;
if (!*len_str || size->cx <= width) break;
(*len_str)--;
}
*len_ellip = len_ellipsis;
*len_before = *len_str;
*len_str += len_ellipsis;
if (modstr)
{
strncpyW (modstr, str, *len_str);
*(str+*len_str) = '\0';
}
}
/*********************************************************************
* TEXT_PathEllipsify (static)
*
* Add an ellipsis to the provided string in order to make it fit within
* the width. The ellipsis is added as specified for the DT_PATH_ELLIPSIS
* flag.
*
* See Also TEXT_Ellipsify
*
* Arguments
* hdc [in] The handle to the DC that defines the font.
* str [in/out] The string that needs to be modified
* max_str [in] The dimension of str (number of WCHAR).
* len_str [in/out] The number of characters in str
* width [in] The maximum width permitted (in logical coordinates)
* size [out] The dimensions of the text
* modstr [out] The modified form of the string, to be returned to the
* calling program. It is assumed that the caller has
* made sufficient space available so we don't need to
* know the size of the space. This pointer may be NULL if
* the modified string is not required.
* pellip [out] The ellipsification results
*
* For now we will simply use three dots rather than worrying about whether
* the font contains an explicit ellipsis character.
*
* The following applies, I think to Win95. We will need to extend it for
* Win98 which can have both path and end ellipsis at the same time (e.g.
* C:\MyLongFileName.Txt becomes ...\MyLongFileN...)
*
* The resulting string consists of as much as possible of the following:
* 1. The ellipsis itself
* 2. The last \ or / of the string (if any)
* 3. Everything after the last \ or / of the string (if any) or the whole
* string if there is no / or \. I believe that under Win95 this would
* include everything even though some might be clipped off the end whereas
* under Win98 that might be ellipsified too.
* Yet to be investigated is whether this would include wordbreaking if the
* filename is more than 1 word and splitting if DT_EDITCONTROL was in
* effect. (If DT_EDITCONTROL is in effect then on occasions text will be
* broken within words).
* 4. All the stuff before the / or \, which is placed before the ellipsis.
*/
static void TEXT_PathEllipsify (HDC hdc, WCHAR *str, unsigned int max_len,
unsigned int *len_str, int width, SIZE *size,
WCHAR *modstr, ellipsis_data *pellip)
{
int len_ellipsis;
int len_trailing;
int len_under;
WCHAR *lastBkSlash, *lastFwdSlash, *lastSlash;
len_ellipsis = strlenW (ELLIPSISW);
if (!max_len) return;
if (len_ellipsis >= max_len) len_ellipsis = max_len - 1;
if (*len_str + len_ellipsis >= max_len)
*len_str = max_len - len_ellipsis-1;
/* Hopefully this will never happen, otherwise it would probably lose
* the wrong character
*/
str[*len_str] = '\0'; /* to simplify things */
lastBkSlash = strrchrW (str, BACK_SLASH);
lastFwdSlash = strrchrW (str, FORWARD_SLASH);
lastSlash = lastBkSlash > lastFwdSlash ? lastBkSlash : lastFwdSlash;
if (!lastSlash) lastSlash = str;
len_trailing = *len_str - (lastSlash - str);
/* overlap-safe movement to the right */
memmove (lastSlash+len_ellipsis, lastSlash, len_trailing * sizeof(WCHAR));
strncpyW (lastSlash, ELLIPSISW, len_ellipsis);
len_trailing += len_ellipsis;
/* From this point on lastSlash actually points to the ellipsis in front
* of the last slash and len_trailing includes the ellipsis
*/
len_under = 0;
for ( ; ; )
{
if (!GetTextExtentExPointW (hdc, str, *len_str + len_ellipsis, width,
NULL, NULL, size)) break;
if (lastSlash == str || size->cx <= width) break;
/* overlap-safe movement to the left */
memmove (lastSlash-1, lastSlash, len_trailing * sizeof(WCHAR));
lastSlash--;
len_under++;
assert (*len_str);
(*len_str)--;
}
pellip->before = lastSlash-str;
pellip->len = len_ellipsis;
pellip->under = len_under;
pellip->after = len_trailing - len_ellipsis;
*len_str += len_ellipsis;
if (modstr)
{
strncpyW (modstr, str, *len_str);
*(str+*len_str) = '\0';
}
}
/*********************************************************************
* TEXT_WordBreak (static)
*
* Perform wordbreak processing on the given string
*
* Assumes that DT_WORDBREAK has been specified and not all the characters
* fit. Note that this function should even be called when the first character
* that doesn't fit is known to be a space or tab, so that it can swallow them.
*
* Note that the Windows processing has some strange properties.
* 1. If the text is left-justified and there is room for some of the spaces
* that follow the last word on the line then those that fit are included on
* the line.
* 2. If the text is centred or right-justified and there is room for some of
* the spaces that follow the last word on the line then all but one of those
* that fit are included on the line.
* 3. (Reasonable behaviour) If the word breaking causes a space to be the first
* character of a new line it will be skipped.
*
* Arguments
* hdc [in] The handle to the DC that defines the font.
* str [in/out] The string that needs to be broken.
* max_str [in] The dimension of str (number of WCHAR).
* len_str [in/out] The number of characters in str
* width [in] The maximum width permitted
* format [in] The format flags in effect
* chars_fit [in] The maximum number of characters of str that are already
* known to fit; chars_fit+1 is known not to fit.
* chars_used [out] The number of characters of str that have been "used" and
* do not need to be included in later text. For example this will
* include any spaces that have been discarded from the start of
* the next line.
* size [out] The size of the returned text in logical coordinates
*
* Pedantic assumption - Assumes that the text length is monotonically
* increasing with number of characters (i.e. no weird kernings)
*
* Algorithm
*
* Work back from the last character that did fit to either a space or the last
* character of a word, whichever is met first.
* If there was one or the first character didn't fit then
* If the text is centred or right justified and that one character was a
* space then break the line before that character
* Otherwise break the line after that character
* and if the next character is a space then discard it.
* Suppose there was none (and the first character did fit).
* If Break Within Word is permitted
* break the word after the last character that fits (there must be
* at least one; none is caught earlier).
* Otherwise
* discard any trailing space.
* include the whole word; it may be ellipsified later
*
* Break Within Word is permitted under a set of circumstances that are not
* totally clear yet. Currently our best guess is:
* If DT_EDITCONTROL is in effect and neither DT_WORD_ELLIPSIS nor
* DT_PATH_ELLIPSIS is
*/
static void TEXT_WordBreak (HDC hdc, WCHAR *str, unsigned int max_str,
unsigned int *len_str,
int width, int format, unsigned int chars_fit,
unsigned int *chars_used, SIZE *size)
{
WCHAR *p;
int word_fits;
assert (format & DT_WORDBREAK);
assert (chars_fit < *len_str);
/* Work back from the last character that did fit to either a space or the
* last character of a word, whichever is met first.
*/
p = str + chars_fit; /* The character that doesn't fit */
word_fits = TRUE;
if (!chars_fit)
; /* we pretend that it fits anyway */
else if (*p == SPACE) /* chars_fit < *len_str so this is valid */
p--; /* the word just fitted */
else
{
while (p > str && *(--p) != SPACE)
;
word_fits = (p != str || *p == SPACE);
}
/* If there was one or the first character didn't fit then */
if (word_fits)
{
/* break the line before/after that character */
if (!(format & (DT_RIGHT | DT_CENTER)) || *p != SPACE)
p++;
*len_str = p - str;
/* and if the next character is a space then discard it. */
*chars_used = *len_str;
if (*p == SPACE)
(*chars_used)++;
}
/* Suppose there was none. */
else
{
if ((format & (DT_EDITCONTROL | DT_WORD_ELLIPSIS | DT_PATH_ELLIPSIS)) ==
DT_EDITCONTROL)
{
/* break the word after the last character that fits (there must be
* at least one; none is caught earlier).
*/
*len_str = chars_fit;
*chars_used = chars_fit;
/* FIXME - possible error. Since the next character is now removed
* this could make the text longer so that it no longer fits, and
* so we need a loop to test and shrink.
*/
}
/* Otherwise */
else
{
/* discard any trailing space. */
const WCHAR *e = str + *len_str;
p = str + chars_fit;
while (p < e && *p != SPACE)
p++;
*chars_used = p - str;
if (p < e) /* i.e. loop failed because *p == SPACE */
(*chars_used)++;
/* include the whole word; it may be ellipsified later */
*len_str = p - str;
/* Possible optimisation; if DT_WORD_ELLIPSIS only use chars_fit+1
* so that it will be too long
*/
}
}
/* Remeasure the string */
GetTextExtentExPointW (hdc, str, *len_str, 0, NULL, NULL, size);
}
/*********************************************************************
* TEXT_SkipChars
*
* Skip over the given number of characters, bearing in mind prefix
* substitution and the fact that a character may take more than one
* WCHAR (Unicode surrogates are two words long) (and there may have been
* a trailing &)
*
* Parameters
* new_count [out] The updated count
* new_str [out] The updated pointer
* start_count [in] The count of remaining characters corresponding to the
* start of the string
* start_str [in] The starting point of the string
* max [in] The number of characters actually in this segment of the
* string (the & counts)
* n [in] The number of characters to skip (if prefix then
* &c counts as one)
* prefix [in] Apply prefix substitution
*
* Return Values
* none
*
* Remarks
* There must be at least n characters in the string
* We need max because the "line" may have ended with a & followed by a tab
* or newline etc. which we don't want to swallow
*/
static void TEXT_SkipChars (int *new_count, const WCHAR **new_str,
int start_count, const WCHAR *start_str,
int max, int n, int prefix)
{
/* This is specific to wide characters, MSDN doesn't say anything much
* about Unicode surrogates yet and it isn't clear if _wcsinc will
* correctly handle them so we'll just do this the easy way for now
*/
if (prefix)
{
const WCHAR *str_on_entry = start_str;
assert (max >= n);
max -= n;
while (n--)
if (*start_str++ == PREFIX && max--)
start_str++;
else;
start_count -= (start_str - str_on_entry);
}
else
{
start_str += n;
start_count -= n;
}
*new_str = start_str;
*new_count = start_count;
}
/*********************************************************************
* TEXT_Reprefix
*
* Reanalyse the text to find the prefixed character. This is called when
* wordbreaking or ellipsification has shortened the string such that the
* previously noted prefixed character is no longer visible.
*
* Parameters
* str [in] The original string segment (including all characters)
* ns [in] The number of characters in str (including prefixes)
* pe [in] The ellipsification data
*
* Return Values
* The prefix offset within the new string segment (the one that contains the
* ellipses and does not contain the prefix characters) (-1 if none)
*/
static int TEXT_Reprefix (const WCHAR *str, unsigned int ns,
const ellipsis_data *pe)
{
int result = -1;
unsigned int i = 0;
unsigned int n = pe->before + pe->under + pe->after;
assert (n <= ns);
while (i < n)
{
if (i == pe->before)
{
/* Reached the path ellipsis; jump over it */
if (ns < pe->under) break;
str += pe->under;
ns -= pe->under;
i += pe->under;
if (!pe->after) break; /* Nothing after the path ellipsis */
}
if (!ns) break;
ns--;
if (*str++ == PREFIX)
{
if (!ns) break;
if (*str != PREFIX)
result = (i < pe->before || pe->under == 0) ? i : i - pe->under + pe->len;
/* pe->len may be non-zero while pe_under is zero */
str++;
ns--;
}
else;
i++;
}
return result;
}
/*********************************************************************
* Returns true if and only if the remainder of the line is a single
* newline representation or nothing
*/
static int remainder_is_none_or_newline (int num_chars, const WCHAR *str)
{
if (!num_chars) return TRUE;
if (*str != LF && *str != CR) return FALSE;
if (!--num_chars) return TRUE;
if (*str == *(str+1)) return FALSE;
str++;
if (*str != CR && *str != LF) return FALSE;
if (--num_chars) return FALSE;
return TRUE;
}
/*********************************************************************
* Return next line of text from a string.
*
* hdc - handle to DC.
* str - string to parse into lines.
* count - length of str.
* dest - destination in which to return line.
* len - dest buffer size in chars on input, copied length into dest on output.
* width - maximum width of line in pixels.
* format - format type passed to DrawText.
* retsize - returned size of the line in pixels.
* last_line - TRUE if is the last line that will be processed
* p_retstr - If DT_MODIFYSTRING this points to a cursor in the buffer in which
* the return string is built.
* tabwidth - The width of a tab in logical coordinates
* pprefix_offset - Here is where we return the offset within dest of the first
* prefixed (underlined) character. -1 is returned if there
* are none. Note that there may be more; the calling code
* will need to use TEXT_Reprefix to find any later ones.
* pellip - Here is where we return the information about any ellipsification
* that was carried out. Note that if tabs are being expanded then
* this data will correspond to the last text segment actually
* returned in dest; by definition there would not have been any
* ellipsification in earlier text segments of the line.
*
* Returns pointer to next char in str after end of the line
* or NULL if end of str reached.
*/
static const WCHAR *TEXT_NextLineW( HDC hdc, const WCHAR *str, int *count,
WCHAR *dest, int *len, int width, DWORD format,
SIZE *retsize, int last_line, WCHAR **p_retstr,
int tabwidth, int *pprefix_offset,
ellipsis_data *pellip)
{
int i = 0, j = 0;
int plen = 0;
SIZE size;
int maxl = *len;
int seg_i, seg_count, seg_j;
int max_seg_width;
int num_fit;
int word_broken;
int line_fits;
int j_in_seg;
int ellipsified;
/* For each text segment in the line */
retsize->cy = 0;
while (*count)
{
/* Skip any leading tabs */
if (str[i] == TAB && (format & DT_EXPANDTABS))
{
plen = ((plen/tabwidth)+1)*tabwidth;
(*count)--; if (j < maxl) dest[j++] = str[i++]; else i++;
while (*count && str[i] == TAB)
{
plen += tabwidth;
(*count)--; if (j < maxl) dest[j++] = str[i++]; else i++;
}
}
/* Now copy as far as the next tab or cr/lf or eos */
seg_i = i;
seg_count = *count;
seg_j = j;
while (*count &&
(str[i] != TAB || !(format & DT_EXPANDTABS)) &&
((str[i] != CR && str[i] != LF) || (format & DT_SINGLELINE)))
{
if (str[i] == PREFIX && !(format & DT_NOPREFIX) && *count > 1)
{
(*count)--, i++; /* Throw away the prefix itself */
if (str[i] == PREFIX)
{
/* Swallow it before we see it again */
(*count)--; if (j < maxl) dest[j++] = str[i++]; else i++;
}
else if (*pprefix_offset == -1 || *pprefix_offset >= seg_j)
{
*pprefix_offset = j;
}
/* else the previous prefix was in an earlier segment of the
* line; we will leave it to the drawing code to catch this
* one.
*/
}
else
{
(*count)--; if (j < maxl) dest[j++] = str[i++]; else i++;
}
}
/* Measure the whole text segment and possibly WordBreak and
* ellipsify it
*/
j_in_seg = j - seg_j;
max_seg_width = width - plen;
GetTextExtentExPointW (hdc, dest + seg_j, j_in_seg, max_seg_width, &num_fit, NULL, &size);
/* The Microsoft handling of various combinations of formats is weird.
* The following may very easily be incorrect if several formats are
* combined, and may differ between versions (to say nothing of the
* several bugs in the Microsoft versions).
*/
word_broken = 0;
line_fits = (num_fit >= j_in_seg);
if (!line_fits && (format & DT_WORDBREAK))
{
const WCHAR *s;
int chars_used;
TEXT_WordBreak (hdc, dest+seg_j, maxl-seg_j, &j_in_seg,
max_seg_width, format, num_fit, &chars_used, &size);
line_fits = (size.cx <= max_seg_width);
/* and correct the counts */
TEXT_SkipChars (count, &s, seg_count, str+seg_i, i-seg_i,
chars_used, !(format & DT_NOPREFIX));
i = s - str;
word_broken = 1;
}
pellip->before = j_in_seg;
pellip->under = 0;
pellip->after = 0;
pellip->len = 0;
ellipsified = 0;
if (!line_fits && (format & DT_PATH_ELLIPSIS))
{
TEXT_PathEllipsify (hdc, dest + seg_j, maxl-seg_j, &j_in_seg,
max_seg_width, &size, *p_retstr, pellip);
line_fits = (size.cx <= max_seg_width);
ellipsified = 1;
}
/* NB we may end up ellipsifying a word-broken or path_ellipsified
* string */
if ((!line_fits && (format & DT_WORD_ELLIPSIS)) ||
((format & DT_END_ELLIPSIS) &&
((last_line && *count) ||
(remainder_is_none_or_newline (*count, &str[i]) && !line_fits))))
{
int before, len_ellipsis;
TEXT_Ellipsify (hdc, dest + seg_j, maxl-seg_j, &j_in_seg,
max_seg_width, &size, *p_retstr, &before, &len_ellipsis);
if (before > pellip->before)
{
/* We must have done a path ellipsis too */
pellip->after = before - pellip->before - pellip->len;
/* Leave the len as the length of the first ellipsis */
}
else
{
/* If we are here after a path ellipsification it must be
* because even the ellipsis itself didn't fit.
*/
assert (pellip->under == 0 && pellip->after == 0);
pellip->before = before;
pellip->len = len_ellipsis;
/* pellip->after remains as zero as does
* pellip->under
*/
}
line_fits = (size.cx <= max_seg_width);
ellipsified = 1;
}
/* As an optimisation if we have ellipsified and we are expanding
* tabs and we haven't reached the end of the line we can skip to it
* now rather than going around the loop again.
*/
if ((format & DT_EXPANDTABS) && ellipsified)
{
if (format & DT_SINGLELINE)
*count = 0;
else
{
while ((*count) && str[i] != CR && str[i] != LF)
{
(*count)--, i++;
}
}
}
j = seg_j + j_in_seg;
if (*pprefix_offset >= seg_j + pellip->before)
{
*pprefix_offset = TEXT_Reprefix (str + seg_i, i - seg_i, pellip);
if (*pprefix_offset != -1)
*pprefix_offset += seg_j;
}
plen += size.cx;
if (size.cy > retsize->cy)
retsize->cy = size.cy;
if (word_broken)
break;
else if (!*count)
break;
else if (str[i] == CR || str[i] == LF)
{
(*count)--, i++;
if (*count && (str[i] == CR || str[i] == LF) && str[i] != str[i-1])
{
(*count)--, i++;
}
break;
}
/* else it was a Tab and we go around again */
}
retsize->cx = plen;
*len = j;
if (*count)
return (&str[i]);
else
return NULL;
}
/***********************************************************************
* TEXT_DrawUnderscore
*
* Draw the underline under the prefixed character
*
* Parameters
* hdc [in] The handle of the DC for drawing
* x [in] The x location of the line segment (logical coordinates)
* y [in] The y location of where the underscore should appear
* (logical coordinates)
* str [in] The text of the line segment
* offset [in] The offset of the underscored character within str
*/
static void TEXT_DrawUnderscore (HDC hdc, int x, int y, const WCHAR *str, int offset)
{
int prefix_x;
int prefix_end;
SIZE size;
HPEN hpen;
HPEN oldPen;
GetTextExtentPointW (hdc, str, offset, &size);
prefix_x = x + size.cx;
GetTextExtentPointW (hdc, str, offset+1, &size);
prefix_end = x + size.cx - 1;
/* The above method may eventually be slightly wrong due to kerning etc. */
hpen = CreatePen (PS_SOLID, 1, GetTextColor (hdc));
oldPen = SelectObject (hdc, hpen);
MoveToEx (hdc, prefix_x, y, NULL);
LineTo (hdc, prefix_end, y);
SelectObject (hdc, oldPen);
DeleteObject (hpen);
}
/***********************************************************************
* DrawTextExW (USER32.@)
*
* The documentation on the extra space required for DT_MODIFYSTRING at MSDN
* is not quite complete, especially with regard to \0. We will assume that
* the returned string could have a length of up to i_count+3 and also have
* a trailing \0 (which would be 4 more than a not-null-terminated string but
* 3 more than a null-terminated string). If this is not so then increase
* the allowance in DrawTextExA.
*/
#define MAX_STATIC_BUFFER 1024
INT WINAPI DrawTextExW( HDC hdc, LPWSTR str, INT i_count,
LPRECT rect, UINT flags, LPDRAWTEXTPARAMS dtp )
{
SIZE size;
const WCHAR *strPtr;
WCHAR *retstr, *p_retstr;
size_t size_retstr;
static WCHAR line[MAX_STATIC_BUFFER];
int len, lh, count=i_count;
TEXTMETRICW tm;
int lmargin = 0, rmargin = 0;
int x = rect->left, y = rect->top;
int width = rect->right - rect->left;
int max_width = 0;
int last_line;
int tabwidth /* to keep gcc happy */ = 0;
int prefix_offset;
ellipsis_data ellip;
TRACE("%s, %d , [(%d,%d),(%d,%d)]\n", debugstr_wn (str, count), count,
rect->left, rect->top, rect->right, rect->bottom);
if (dtp) TRACE("Params: iTabLength=%d, iLeftMargin=%d, iRightMargin=%d\n",
dtp->iTabLength, dtp->iLeftMargin, dtp->iRightMargin);
if (!str) return 0;
if (count == -1) count = strlenW(str);
if (count == 0) return 0;
strPtr = str;
if (flags & DT_SINGLELINE)
flags &= ~DT_WORDBREAK;
GetTextMetricsW(hdc, &tm);
if (flags & DT_EXTERNALLEADING)
lh = tm.tmHeight + tm.tmExternalLeading;
else
lh = tm.tmHeight;
if (dtp)
{
lmargin = dtp->iLeftMargin * tm.tmAveCharWidth;
rmargin = dtp->iRightMargin * tm.tmAveCharWidth;
if (!(flags & (DT_CENTER | DT_RIGHT)))
x += lmargin;
dtp->uiLengthDrawn = 0; /* This param RECEIVES number of chars processed */
}
if (flags & DT_EXPANDTABS)
{
int tabstop = ((flags & DT_TABSTOP) && dtp) ? dtp->iTabLength : 8;
tabwidth = tm.tmAveCharWidth * tabstop;
}
if (flags & DT_CALCRECT) flags |= DT_NOCLIP;
if (flags & DT_MODIFYSTRING)
{
size_retstr = (count + 4) * sizeof (WCHAR);
retstr = HeapAlloc(GetProcessHeap(), 0, size_retstr);
if (!retstr) return 0;
memcpy (retstr, str, size_retstr);
}
else
{
size_retstr = 0;
retstr = NULL;
}
p_retstr = retstr;
do
{
len = MAX_STATIC_BUFFER;
last_line = !(flags & DT_NOCLIP) && y + ((flags & DT_EDITCONTROL) ? 2*lh-1 : lh) > rect->bottom;
strPtr = TEXT_NextLineW(hdc, strPtr, &count, line, &len, width, flags, &size, last_line, &p_retstr, tabwidth, &prefix_offset, &ellip);
if (flags & DT_CENTER) x = (rect->left + rect->right -
size.cx) / 2;
else if (flags & DT_RIGHT) x = rect->right - size.cx;
if (flags & DT_SINGLELINE)
{
if (flags & DT_VCENTER) y = rect->top +
(rect->bottom - rect->top) / 2 - size.cy / 2;
else if (flags & DT_BOTTOM) y = rect->bottom - size.cy;
}
if (!(flags & DT_CALCRECT))
{
const WCHAR *str = line;
int xseg = x;
while (len)
{
int len_seg;
SIZE size;
if ((flags & DT_EXPANDTABS))
{
const WCHAR *p;
p = str; while (p < str+len && *p != TAB) p++;
len_seg = p - str;
if (len_seg != len && !GetTextExtentPointW(hdc, str, len_seg, &size))
return 0;
}
else
len_seg = len;
if (!ExtTextOutW( hdc, xseg, y,
((flags & DT_NOCLIP) ? 0 : ETO_CLIPPED) |
((flags & DT_RTLREADING) ? ETO_RTLREADING : 0),
rect, str, len_seg, NULL )) return 0;
if (prefix_offset != -1 && prefix_offset < len_seg)
{
TEXT_DrawUnderscore (hdc, xseg, y + tm.tmAscent + 1, str, prefix_offset);
}
len -= len_seg;
str += len_seg;
if (len)
{
assert ((flags & DT_EXPANDTABS) && *str == TAB);
len--; str++;
xseg += ((size.cx/tabwidth)+1)*tabwidth;
if (prefix_offset != -1)
{
if (prefix_offset < len_seg)
{
/* We have just drawn an underscore; we ought to
* figure out where the next one is. I am going
* to leave it for now until I have a better model
* for the line, which will make reprefixing easier.
* This is where ellip would be used.
*/
prefix_offset = -1;
}
else
prefix_offset -= len_seg;
}
}
}
}
else if (size.cx > max_width)
max_width = size.cx;
y += lh;
if (dtp)
dtp->uiLengthDrawn += len;
}
while (strPtr && !last_line);
if (flags & DT_CALCRECT)
{
rect->right = rect->left + max_width;
rect->bottom = y;
if (dtp)
rect->right += lmargin + rmargin;
}
if (retstr)
{
memcpy (str, retstr, size_retstr);
HeapFree (GetProcessHeap(), 0, retstr);
}
return y - rect->top;
}
/***********************************************************************
* DrawTextExA (USER32.@)
*
* If DT_MODIFYSTRING is specified then there must be room for up to
* 4 extra characters. We take great care about just how much modified
* string we return.
*/
INT WINAPI DrawTextExA( HDC hdc, LPSTR str, INT count,
LPRECT rect, UINT flags, LPDRAWTEXTPARAMS dtp )
{
WCHAR *wstr;
WCHAR *p;
INT ret = 0;
int i;
DWORD wcount;
DWORD wmax;
DWORD amax;
if (count == -1) count = strlen(str);
if (!count) return 0;
wcount = MultiByteToWideChar( CP_ACP, 0, str, count, NULL, 0 );
wmax = wcount;
amax = count;
if (flags & DT_MODIFYSTRING)
{
wmax += 4;
amax += 4;
}
wstr = HeapAlloc(GetProcessHeap(), 0, wmax * sizeof(WCHAR));
if (wstr)
{
MultiByteToWideChar( CP_ACP, 0, str, count, wstr, wcount );
if (flags & DT_MODIFYSTRING)
for (i=4, p=wstr+wcount; i--; p++) *p=0xFFFE;
/* Initialise the extra characters so that we can see which ones
* change. U+FFFE is guaranteed to be not a unicode character and
* so will not be generated by DrawTextEx itself.
*/
ret = DrawTextExW( hdc, wstr, wcount, rect, flags, NULL );
if (flags & DT_MODIFYSTRING)
{
/* Unfortunately the returned string may contain multiple \0s
* and so we need to measure it ourselves.
*/
for (i=4, p=wstr+wcount; i-- && *p != 0xFFFE; p++) wcount++;
WideCharToMultiByte( CP_ACP, 0, wstr, wcount, str, amax, NULL, NULL );
}
HeapFree(GetProcessHeap(), 0, wstr);
}
return ret;
}
/***********************************************************************
* DrawTextW (USER32.@)
*/
INT WINAPI DrawTextW( HDC hdc, LPCWSTR str, INT count, LPRECT rect, UINT flags )
{
DRAWTEXTPARAMS dtp;
memset (&dtp, 0, sizeof(dtp));
if (flags & DT_TABSTOP)
{
dtp.iTabLength = (flags >> 8) && 0xff;
flags &= 0xffff00ff;
}
return DrawTextExW(hdc, (LPWSTR)str, count, rect, flags, &dtp);
}
/***********************************************************************
* DrawTextA (USER32.@)
*/
INT WINAPI DrawTextA( HDC hdc, LPCSTR str, INT count, LPRECT rect, UINT flags )
{
DRAWTEXTPARAMS dtp;
memset (&dtp, 0, sizeof(dtp));
if (flags & DT_TABSTOP)
{
dtp.iTabLength = (flags >> 8) && 0xff;
flags &= 0xffff00ff;
}
return DrawTextExA( hdc, (LPSTR)str, count, rect, flags, &dtp );
}
/***********************************************************************
* DrawText (USER.85)
*/
INT16 WINAPI DrawText16( HDC16 hdc, LPCSTR str, INT16 count, LPRECT16 rect, UINT16 flags )
{
INT16 ret;
if (rect)
{
RECT rect32;
CONV_RECT16TO32( rect, &rect32 );
ret = DrawTextA( hdc, str, count, &rect32, flags );
CONV_RECT32TO16( &rect32, rect );
}
else ret = DrawTextA( hdc, str, count, NULL, flags);
return ret;
}
/***********************************************************************
*
* GrayString functions
*/
/* ### start build ### */
extern WORD CALLBACK TEXT_CallTo16_word_wlw(GRAYSTRINGPROC16,WORD,LONG,WORD);
/* ### stop build ### */
struct gray_string_info
{
GRAYSTRINGPROC16 proc;
LPARAM param;
};
/* callback for 16-bit gray string proc */
static BOOL CALLBACK gray_string_callback( HDC hdc, LPARAM param, INT len )
{
const struct gray_string_info *info = (struct gray_string_info *)param;
return TEXT_CallTo16_word_wlw( info->proc, hdc, info->param, len );
}
/***********************************************************************
* TEXT_GrayString
*
* FIXME: The call to 16-bit code only works because the wine GDI is a 16-bit
* heap and we can guarantee that the handles fit in an INT16. We have to
* rethink the strategy once the migration to NT handles is complete.
* We are going to get a lot of code-duplication once this migration is
* completed...
*
*/
static BOOL TEXT_GrayString(HDC hdc, HBRUSH hb, GRAYSTRINGPROC fn, LPARAM lp, INT len,
INT x, INT y, INT cx, INT cy, BOOL unicode, BOOL _32bit)
{
HBITMAP hbm, hbmsave;
HBRUSH hbsave;
HFONT hfsave;
HDC memdc;
int slen = len;
BOOL retval = TRUE;
COLORREF fg, bg;
if(!hdc) return FALSE;
if (!(memdc = CreateCompatibleDC(hdc))) return FALSE;
if(len == 0)
{
if(unicode)
slen = lstrlenW((LPCWSTR)lp);
else if(_32bit)
slen = strlen((LPCSTR)lp);
else
slen = strlen(MapSL(lp));
}
if((cx == 0 || cy == 0) && slen != -1)
{
SIZE s;
if(unicode)
GetTextExtentPoint32W(hdc, (LPCWSTR)lp, slen, &s);
else if(_32bit)
GetTextExtentPoint32A(hdc, (LPCSTR)lp, slen, &s);
else
GetTextExtentPoint32A(hdc, MapSL(lp), slen, &s);
if(cx == 0) cx = s.cx;
if(cy == 0) cy = s.cy;
}
hbm = CreateBitmap(cx, cy, 1, 1, NULL);
hbmsave = (HBITMAP)SelectObject(memdc, hbm);
hbsave = SelectObject( memdc, GetStockObject(BLACK_BRUSH) );
PatBlt( memdc, 0, 0, cx, cy, PATCOPY );
SelectObject( memdc, hbsave );
SetTextColor(memdc, RGB(255, 255, 255));
SetBkColor(memdc, RGB(0, 0, 0));
hfsave = (HFONT)SelectObject(memdc, GetCurrentObject(hdc, OBJ_FONT));
if(fn)
{
if(_32bit)
retval = fn(memdc, lp, slen);
else
retval = (BOOL)((BOOL16)((GRAYSTRINGPROC16)fn)((HDC16)memdc, lp, (INT16)slen));
}
else
{
if(unicode)
TextOutW(memdc, 0, 0, (LPCWSTR)lp, slen);
else if(_32bit)
TextOutA(memdc, 0, 0, (LPCSTR)lp, slen);
else
TextOutA(memdc, 0, 0, MapSL(lp), slen);
}
SelectObject(memdc, hfsave);
/*
* Windows doc says that the bitmap isn't grayed when len == -1 and
* the callback function returns FALSE. However, testing this on
* win95 showed otherwise...
*/
#ifdef GRAYSTRING_USING_DOCUMENTED_BEHAVIOUR
if(retval || len != -1)
#endif
{
hbsave = (HBRUSH)SelectObject(memdc, CACHE_GetPattern55AABrush());
PatBlt(memdc, 0, 0, cx, cy, 0x000A0329);
SelectObject(memdc, hbsave);
}
if(hb) hbsave = (HBRUSH)SelectObject(hdc, hb);
fg = SetTextColor(hdc, RGB(0, 0, 0));
bg = SetBkColor(hdc, RGB(255, 255, 255));
BitBlt(hdc, x, y, cx, cy, memdc, 0, 0, 0x00E20746);
SetTextColor(hdc, fg);
SetBkColor(hdc, bg);
if(hb) SelectObject(hdc, hbsave);
SelectObject(memdc, hbmsave);
DeleteObject(hbm);
DeleteDC(memdc);
return retval;
}
/***********************************************************************
* GrayString (USER.185)
*/
BOOL16 WINAPI GrayString16( HDC16 hdc, HBRUSH16 hbr, GRAYSTRINGPROC16 gsprc,
LPARAM lParam, INT16 cch, INT16 x, INT16 y,
INT16 cx, INT16 cy )
{
struct gray_string_info info;
if (!gsprc) return TEXT_GrayString(hdc, hbr, NULL, lParam, cch, x, y, cx, cy, FALSE, FALSE);
info.proc = gsprc;
info.param = lParam;
return TEXT_GrayString( hdc, hbr, gray_string_callback, (LPARAM)&info,
cch, x, y, cx, cy, FALSE, FALSE);
}
/***********************************************************************
* GrayStringA (USER32.@)
*/
BOOL WINAPI GrayStringA( HDC hdc, HBRUSH hbr, GRAYSTRINGPROC gsprc,
LPARAM lParam, INT cch, INT x, INT y,
INT cx, INT cy )
{
return TEXT_GrayString(hdc, hbr, gsprc, lParam, cch, x, y, cx, cy,
FALSE, TRUE);
}
/***********************************************************************
* GrayStringW (USER32.@)
*/
BOOL WINAPI GrayStringW( HDC hdc, HBRUSH hbr, GRAYSTRINGPROC gsprc,
LPARAM lParam, INT cch, INT x, INT y,
INT cx, INT cy )
{
return TEXT_GrayString(hdc, hbr, gsprc, lParam, cch, x, y, cx, cy,
TRUE, TRUE);
}
/***********************************************************************
*
* TabbedText functions
*/
/***********************************************************************
* TEXT_TabbedTextOut
*
* Helper function for TabbedTextOut() and GetTabbedTextExtent().
* Note: this doesn't work too well for text-alignment modes other
* than TA_LEFT|TA_TOP. But we want bug-for-bug compatibility :-)
*/
static LONG TEXT_TabbedTextOut( HDC hdc, INT x, INT y, LPCSTR lpstr,
INT count, INT cTabStops, const INT16 *lpTabPos16,
const INT *lpTabPos32, INT nTabOrg,
BOOL fDisplayText )
{
INT defWidth;
SIZE extent;
int i, tabPos = x;
int start = x;
extent.cx = 0;
extent.cy = 0;
if (cTabStops == 1)
{
defWidth = lpTabPos32 ? *lpTabPos32 : *lpTabPos16;
cTabStops = 0;
}
else
{
TEXTMETRICA tm;
GetTextMetricsA( hdc, &tm );
defWidth = 8 * tm.tmAveCharWidth;
}
while (count > 0)
{
for (i = 0; i < count; i++)
if (lpstr[i] == '\t') break;
GetTextExtentPointA( hdc, lpstr, i, &extent );
if (lpTabPos32)
{
while ((cTabStops > 0) &&
(nTabOrg + *lpTabPos32 <= x + extent.cx))
{
lpTabPos32++;
cTabStops--;
}
}
else
{
while ((cTabStops > 0) &&
(nTabOrg + *lpTabPos16 <= x + extent.cx))
{
lpTabPos16++;
cTabStops--;
}
}
if (i == count)
tabPos = x + extent.cx;
else if (cTabStops > 0)
tabPos = nTabOrg + (lpTabPos32 ? *lpTabPos32 : *lpTabPos16);
else
tabPos = nTabOrg + ((x + extent.cx - nTabOrg) / defWidth + 1) * defWidth;
if (fDisplayText)
{
RECT r;
r.left = x;
r.top = y;
r.right = tabPos;
r.bottom = y + extent.cy;
ExtTextOutA( hdc, x, y,
GetBkMode(hdc) == OPAQUE ? ETO_OPAQUE : 0,
&r, lpstr, i, NULL );
}
x = tabPos;
count -= i+1;
lpstr += i+1;
}
return MAKELONG(tabPos - start, extent.cy);
}
/***********************************************************************
* TabbedTextOut (USER.196)
*/
LONG WINAPI TabbedTextOut16( HDC16 hdc, INT16 x, INT16 y, LPCSTR lpstr,
INT16 count, INT16 cTabStops,
const INT16 *lpTabPos, INT16 nTabOrg )
{
TRACE("%04x %d,%d %s %d\n", hdc, x, y, debugstr_an(lpstr,count), count );
return TEXT_TabbedTextOut( hdc, x, y, lpstr, count, cTabStops,
lpTabPos, NULL, nTabOrg, TRUE );
}
/***********************************************************************
* TabbedTextOutA (USER32.@)
*/
LONG WINAPI TabbedTextOutA( HDC hdc, INT x, INT y, LPCSTR lpstr, INT count,
INT cTabStops, const INT *lpTabPos, INT nTabOrg )
{
TRACE("%04x %d,%d %s %d\n", hdc, x, y, debugstr_an(lpstr,count), count );
return TEXT_TabbedTextOut( hdc, x, y, lpstr, count, cTabStops,
NULL, lpTabPos, nTabOrg, TRUE );
}
/***********************************************************************
* TabbedTextOutW (USER32.@)
*/
LONG WINAPI TabbedTextOutW( HDC hdc, INT x, INT y, LPCWSTR str, INT count,
INT cTabStops, const INT *lpTabPos, INT nTabOrg )
{
LONG ret;
LPSTR p;
INT acount;
UINT codepage = CP_ACP; /* FIXME: get codepage of font charset */
acount = WideCharToMultiByte(codepage,0,str,count,NULL,0,NULL,NULL);
p = HeapAlloc( GetProcessHeap(), 0, acount );
if(p == NULL) return 0; /* FIXME: is this the correct return on failure */
acount = WideCharToMultiByte(codepage,0,str,count,p,acount,NULL,NULL);
ret = TabbedTextOutA( hdc, x, y, p, acount, cTabStops, lpTabPos, nTabOrg );
HeapFree( GetProcessHeap(), 0, p );
return ret;
}
/***********************************************************************
* GetTabbedTextExtent (USER.197)
*/
DWORD WINAPI GetTabbedTextExtent16( HDC16 hdc, LPCSTR lpstr, INT16 count,
INT16 cTabStops, const INT16 *lpTabPos )
{
TRACE("%04x %s %d\n", hdc, debugstr_an(lpstr,count), count );
return TEXT_TabbedTextOut( hdc, 0, 0, lpstr, count, cTabStops,
lpTabPos, NULL, 0, FALSE );
}
/***********************************************************************
* GetTabbedTextExtentA (USER32.@)
*/
DWORD WINAPI GetTabbedTextExtentA( HDC hdc, LPCSTR lpstr, INT count,
INT cTabStops, const INT *lpTabPos )
{
TRACE("%04x %s %d\n", hdc, debugstr_an(lpstr,count), count );
return TEXT_TabbedTextOut( hdc, 0, 0, lpstr, count, cTabStops,
NULL, lpTabPos, 0, FALSE );
}
/***********************************************************************
* GetTabbedTextExtentW (USER32.@)
*/
DWORD WINAPI GetTabbedTextExtentW( HDC hdc, LPCWSTR lpstr, INT count,
INT cTabStops, const INT *lpTabPos )
{
LONG ret;
LPSTR p;
INT acount;
UINT codepage = CP_ACP; /* FIXME: get codepage of font charset */
acount = WideCharToMultiByte(codepage,0,lpstr,count,NULL,0,NULL,NULL);
p = HeapAlloc( GetProcessHeap(), 0, acount );
if(p == NULL) return 0; /* FIXME: is this the correct failure value? */
acount = WideCharToMultiByte(codepage,0,lpstr,count,p,acount,NULL,NULL);
ret = GetTabbedTextExtentA( hdc, p, acount, cTabStops, lpTabPos );
HeapFree( GetProcessHeap(), 0, p );
return ret;
}