/**
* Find where to split a string to make it fit a width.
*
* \param[in] fstyle style for this text
* \param[in] string UTF-8 string to measure
* \param[in] length length of string, in bytes
* \param[in] x width available
* \param[out] char_offset updated to offset in string of actual_x, [1..length]
* \param[out] actual_x updated to x coordinate of character closest to x
* \return NSERROR_OK or appropriate error code on faliure
*
* On exit, char_offset indicates first character after split point.
*
* \note char_offset of 0 must never be returned.
*
* Returns:
* char_offset giving split point closest to x, where actual_x <= x
* else
* char_offset giving split point closest to x, where actual_x > x
*
* Returning char_offset == length means no split possible
*/
static nserror
nsfont_split(const plot_font_style_t *fstyle,
const char *string,
size_t length,
int x,
size_t *char_offset,
int *actual_x)
{
int index = length;
PangoFontDescription *desc;
PangoContext *context;
PangoLayout *layout;
PangoLayoutLine *line;
context = gdk_pango_context_get();
layout = pango_layout_new(context);
desc = nsfont_style_to_description(fstyle);
pango_layout_set_font_description(layout, desc);
pango_font_description_free(desc);
pango_layout_set_text(layout, string, length);
/* Limit width of layout to the available width */
pango_layout_set_width(layout, x * PANGO_SCALE);
/* Request word wrapping */
pango_layout_set_wrap(layout, PANGO_WRAP_WORD);
/* Prevent pango treating linebreak characters as line breaks */
pango_layout_set_single_paragraph_mode(layout, TRUE);
/* Obtain the second line of the layout (if there is one) */
line = pango_layout_get_line(layout, 1);
if (line != NULL) {
/* Pango split the text. The line's start_index indicates the
* start of the character after the line break. */
index = line->start_index;
}
g_object_unref(layout);
g_object_unref(context);
*char_offset = index;
/* Obtain the pixel offset of the split character */
nsfont_width(fstyle, string, index, actual_x);
return NSERROR_OK;
}
static bool nsfont_position_in_string(const plot_font_style_t *style,
const char *string, size_t length,
int x, size_t *char_offset, int *actual_x)
{
HDC hdc = GetDC(NULL);
HFONT font = get_font(style);
HFONT fontbak = SelectObject(hdc, font);
SIZE s;
int offset;
GetTextExtentExPoint(hdc, string, length, x, &offset, NULL, &s);
*char_offset = (size_t)offset;
nsfont_width(style, string, *char_offset, actual_x);
font = SelectObject(hdc, fontbak);
DeleteObject(font);
ReleaseDC(NULL, hdc);
return true;
}
