pangowin32.c

Pango is a library for layout and rendering of text, with an emphasis on internationalization. Pang

      info = g_new0 (PangoWin32GlyphInfo, 1);

      memset (&gm, 0, sizeof (gm));

      hfont = pango_win32_get_hfont (font);
      SelectObject (_pango_win32_hdc, hfont);
      /* FIXME: (Alex) This constant reuse of _pango_win32_hdc is
	 not thread-safe */
      res = GetGlyphOutlineA (_pango_win32_hdc,
			      glyph_index,
			      GGO_METRICS | GGO_GLYPH_INDEX,
			      &gm,
			      0, NULL,
			      &m);

      if (res == GDI_ERROR)
	{
	  gchar *error = g_win32_error_message (GetLastError ());
	  g_warning ("GetGlyphOutline(%04X) failed: %s\n",
		     glyph_index, error);
	  g_free (error);

	  /* Don't just return now, use the still zeroed out gm */
	}

      info->ink_rect.x = PANGO_SCALE * gm.gmptGlyphOrigin.x;
      info->ink_rect.width = PANGO_SCALE * gm.gmBlackBoxX;
      info->ink_rect.y = - PANGO_SCALE * gm.gmptGlyphOrigin.y;
      info->ink_rect.height = PANGO_SCALE * gm.gmBlackBoxY;

      info->logical_rect.x = 0;
      info->logical_rect.width = PANGO_SCALE * gm.gmCellIncX;
      info->logical_rect.y = - PANGO_SCALE * win32font->tm_ascent;
      info->logical_rect.height = PANGO_SCALE * (win32font->tm_ascent + win32font->tm_descent);

      g_hash_table_insert (win32font->glyph_info, GUINT_TO_POINTER(glyph), info);
    }

  if (ink_rect)
    *ink_rect = info->ink_rect;

  if (logical_rect)
    *logical_rect = info->logical_rect;
}

static int
max_glyph_width (PangoLayout *layout)
{
  int max_width = 0;
  GSList *l, *r;

  for (l = pango_layout_get_lines_readonly (layout); l; l = l->next)
    {
      PangoLayoutLine *line = l->data;

      for (r = line->runs; r; r = r->next)
	{
	  PangoGlyphString *glyphs = ((PangoGlyphItem *)r->data)->glyphs;
	  int i;

	  for (i = 0; i < glyphs->num_glyphs; i++)
	    if (glyphs->glyphs[i].geometry.width > max_width)
	      max_width = glyphs->glyphs[i].geometry.width;
	}
    }

  return max_width;
}

static PangoFontMetrics *
pango_win32_font_get_metrics (PangoFont     *font,
			      PangoLanguage *language)
{
  PangoWin32MetricsInfo *info = NULL; /* Quiet gcc */
  PangoWin32Font *win32font = (PangoWin32Font *)font;
  GSList *tmp_list;

  const char *sample_str = pango_language_get_sample_string (language);

  tmp_list = win32font->metrics_by_lang;
  while (tmp_list)
    {
      info = tmp_list->data;

      if (info->sample_str == sample_str)    /* We _don't_ need strcmp */
	break;

      tmp_list = tmp_list->next;
    }

  if (!tmp_list)
    {
      HFONT hfont;
      PangoFontMetrics *metrics;

      info = g_new (PangoWin32MetricsInfo, 1);
      win32font->metrics_by_lang = g_slist_prepend (win32font->metrics_by_lang, info);

      info->sample_str = sample_str;
      info->metrics = metrics = pango_font_metrics_new ();

      hfont = pango_win32_get_hfont (font);
      if (hfont != NULL)
	{
	  PangoCoverage *coverage;
	  TEXTMETRIC tm;

	  SelectObject (_pango_win32_hdc, hfont);
	  GetTextMetrics (_pango_win32_hdc, &tm);

	  metrics->ascent = tm.tmAscent * PANGO_SCALE;
	  metrics->descent = tm.tmDescent * PANGO_SCALE;
	  metrics->approximate_char_width = tm.tmAveCharWidth * PANGO_SCALE;

	  coverage = pango_win32_font_get_coverage (font, language);
	  if (pango_coverage_get (coverage, '0') != PANGO_COVERAGE_NONE &&
	      pango_coverage_get (coverage, '9') != PANGO_COVERAGE_NONE)
	    {
	      PangoContext *context;
	      PangoFontDescription *font_desc;
	      PangoLayout *layout;

	      /*  Get the average width of the chars in "0123456789" */
	      context = pango_win32_get_context ();
	      pango_context_set_language (context, language);
	      font_desc = pango_font_describe_with_absolute_size (font);
	      pango_context_set_font_description (context, font_desc);
	      layout = pango_layout_new (context);
	      pango_layout_set_text (layout, "0123456789", -1);

	      metrics->approximate_digit_width = max_glyph_width (layout);

	      pango_font_description_free (font_desc);
	      g_object_unref (layout);
	      g_object_unref (context);
	    }
	  else
	    metrics->approximate_digit_width = metrics->approximate_char_width;

	  pango_coverage_unref (coverage);

	  /* FIXME: Should get the real values from the TrueType font file */
	  metrics->underline_position = -2 * PANGO_SCALE;
	  metrics->underline_thickness = 1 * PANGO_SCALE;
	  metrics->strikethrough_thickness = metrics->underline_thickness;
	  /* Really really wild guess */
	  metrics->strikethrough_position = metrics->ascent / 3;
	}
    }

  return pango_font_metrics_ref (info->metrics);
}

static PangoFontMap *
pango_win32_font_get_font_map (PangoFont *font)
{
  PangoWin32Font *win32font = (PangoWin32Font *)font;

  return win32font->fontmap;
}

static gboolean
pango_win32_font_real_select_font (PangoFont *font,
				   HDC        hdc)
{
  HFONT hfont = pango_win32_get_hfont (font);

  if (!hfont)
    return FALSE;

  if (!SelectObject (hdc, hfont))
    {
      g_warning ("pango_win32_font_real_select_font: Cannot select font\n");
      return FALSE;
    }

  return TRUE;
}

static void
pango_win32_font_real_done_font (PangoFont *font)
{
}

static double
pango_win32_font_real_get_metrics_factor (PangoFont *font)
{
  return PANGO_SCALE;
}

/**
 * pango_win32_font_logfont:
 * @font: a #PangoFont which must be from the Win32 backend
 *
 * Determine the LOGFONTA struct for the specified font. Note that
 * Pango internally uses LOGFONTW structs, so if converting the UTF-16
 * face name in the LOGFONTW struct to system codepage fails, the
 * returned LOGFONTA will have an emppty face name. To get the
 * LOGFONTW of a PangoFont, use pango_win32_font_logfontw(). It
 * is recommended to do that always even if you don't expect
 * to come across fonts with odd names.
 *
 * Return value: A newly allocated LOGFONTA struct. It must be
 * freed with g_free().
 **/
LOGFONTA *
pango_win32_font_logfont (PangoFont *font)
{
  PangoWin32Font *win32font = (PangoWin32Font *)font;
  LOGFONTA *lfp;

  g_return_val_if_fail (font != NULL, NULL);
  g_return_val_if_fail (PANGO_WIN32_IS_FONT (font), NULL);

  lfp = g_new (LOGFONTA, 1);

  *lfp = *(LOGFONTA*) &win32font->logfontw;
  if (!WideCharToMultiByte (CP_ACP, 0,
			    win32font->logfontw.lfFaceName, -1,
			    lfp->lfFaceName, G_N_ELEMENTS (lfp->lfFaceName),
			    NULL, NULL))
    lfp->lfFaceName[0] = '\0';

  return lfp;
}

/**
 * pango_win32_font_logfontw:
 * @font: a #PangoFont which must be from the Win32 backend
 * 
 * Determine the LOGFONTW struct for the specified font.
 * 
 * Return value: A newly allocated LOGFONTW struct. It must be
 * freed with g_free().
 *
 * Since: 1.16
 **/
LOGFONTW *
pango_win32_font_logfontw (PangoFont *font)
{
  PangoWin32Font *win32font = (PangoWin32Font *)font;
  LOGFONTW *lfp;

  g_return_val_if_fail (font != NULL, NULL);
  g_return_val_if_fail (PANGO_WIN32_IS_FONT (font), NULL);

  lfp = g_new (LOGFONTW, 1);
  *lfp = win32font->logfontw;

  return lfp;
}

/**
 * pango_win32_font_select_font:
 * @font: a #PangoFont from the Win32 backend
 * @hdc: a windows device context
 *
 * Selects the font into the specified DC and changes the mapping mode
 * and world transformation of the DC appropriately for the font.
 * You may want to surround the use of this function with calls
 * to SaveDC() and RestoreDC(). Call pango_win32_font_done_font() when
 * you are done using the DC to release allocated resources.
 *
 * See pango_win32_font_get_metrics_factor() for information about
 * converting from the coordinate space used by this function
 * into Pango units.
 *
 * Return value: %TRUE if the operation succeeded.
 **/
gboolean
pango_win32_font_select_font (PangoFont *font,
			      HDC        hdc)
{
  g_return_val_if_fail (PANGO_WIN32_IS_FONT (font), FALSE);

  return PANGO_WIN32_FONT_GET_CLASS (font)->select_font (font, hdc);
}

/**
 * pango_win32_font_done_font:
 * @font: a #PangoFont from the win32 backend
 *
 * Releases any resources allocated by pango_win32_font_done_font()
 **/
void
pango_win32_font_done_font (PangoFont *font)
{
  g_return_if_fail (PANGO_WIN32_IS_FONT (font));

  PANGO_WIN32_FONT_GET_CLASS (font)->done_font (font);
}

/**
 * pango_win32_font_get_metrics_factor:
 * @font: a #PangoFont from the win32 backend
 *
 * Returns the scale factor from logical units in the coordinate
 * space used by pango_win32_font_select_font() to Pango units
 * in user space.
 *
 * Return value: factor to multiply logical units by to get Pango
 *               units.
 **/
double
pango_win32_font_get_metrics_factor (PangoFont *font)
{
  g_return_val_if_fail (PANGO_WIN32_IS_FONT (font), 1.);

  return PANGO_WIN32_FONT_GET_CLASS (font)->get_metrics_factor (font);
}

static void
pango_win32_fontmap_cache_add (PangoFontMap   *fontmap,
			       PangoWin32Font *win32font)
{
  PangoWin32FontMap *win32fontmap = PANGO_WIN32_FONT_MAP (fontmap);

  if (win32fontmap->freed_fonts->length == MAX_FREED_FONTS)
    {
      PangoWin32Font *old_font = g_queue_pop_tail (win32fontmap->freed_fonts);
      g_object_unref (old_font);
    }

  g_object_ref (win32font);
  g_queue_push_head (win32fontmap->freed_fonts, win32font);
  win32font->in_cache = TRUE;
}

static void
pango_win32_font_dispose (GObject *object)
{
  PangoWin32Font *win32font = PANGO_WIN32_FONT (object);

  /* If the font is not already in the freed-fonts cache, add it,
   * if it is already there, do nothing and the font will be
   * freed.
   */
  if (!win32font->in_cache && win32font->fontmap)
    pango_win32_fontmap_cache_add (win32font->fontmap, win32font);

  G_OBJECT_CLASS (_pango_win32_font_parent_class)->dispose (object);
}

static void
free_metrics_info (PangoWin32MetricsInfo *info)
{
  pango_font_metrics_unref (info->metrics);
  g_free (info);
}

static void
pango_win32_font_entry_remove (PangoWin32Face *face,
			       PangoFont      *font)
{
  face->cached_fonts = g_slist_remove (face->cached_fonts, font);
}

static void
pango_win32_font_finalize (GObject *object)
{
  PangoWin32Font *win32font = (PangoWin32Font *)object;
  PangoWin32FontCache *cache = pango_win32_font_map_get_font_cache (win32font->fontmap);

  if (win32font->hfont != NULL)
    pango_win32_font_cache_unload (cache, win32font->hfont);

  g_slist_foreach (win32font->metrics_by_lang, (GFunc)free_metrics_info, NULL);
  g_slist_free (win32font->metrics_by_lang);

  if (win32font->win32face)
    pango_win32_font_entry_remove (win32font->win32face, PANGO_FONT (win32font));

  g_hash_table_destroy (win32font->glyph_info);

  g_object_unref (win32font->fontmap);

  G_OBJECT_CLASS (_pango_win32_font_parent_class)->finalize (object);
}

static PangoFontDescription *
pango_win32_font_describe (PangoFont *font)
{
  PangoFontDescription *desc;
  PangoWin32Font *win32font = PANGO_WIN32_FONT (font);

  desc = pango_font_description_copy (win32font->win32face->description);
  pango_font_description_set_size (desc, win32font->size / (PANGO_SCALE / PANGO_WIN32_FONT_MAP (win32font->fontmap)->resolution));

  return desc;
}

static PangoFontDescription *
pango_win32_font_describe_absolute (PangoFont *font)
{
  PangoFontDescription *desc;
  PangoWin32Font *win32font = PANGO_WIN32_FONT (font);

  desc = pango_font_description_copy (win32font->win32face->description);
  pango_font_description_set_absolute_size (desc, win32font->size);

  return desc;
}

static PangoMap *
pango_win32_get_shaper_map (PangoLanguage *lang)
{
  static guint engine_type_id = 0;
  static guint render_type_id = 0;

  if (engine_type_id == 0)
    {
      engine_type_id = g_quark_from_static_string (PANGO_ENGINE_TYPE_SHAPE);
      render_type_id = g_quark_from_static_string (PANGO_RENDER_TYPE_WIN32);
    }

  return pango_find_map (lang, engine_type_id, render_type_id);
}

static gint
pango_win32_coverage_language_classify (PangoLanguage *lang)
{
  if (pango_language_matches (lang, "zh-tw"))
    return PANGO_WIN32_COVERAGE_ZH_TW;
  else if (pango_language_matches (lang, "zh-cn"))
    return PANGO_WIN32_COVERAGE_ZH_CN;
  else if (pango_language_matches (lang, "ja"))
    return PANGO_WIN32_COVERAGE_JA;
  else if (pango_language_matches (lang, "ko"))
    return PANGO_WIN32_COVERAGE_KO;
  else if (pango_language_matches (lang, "vi"))
    return PANGO_WIN32_COVERAGE_VI;
  else
    return PANGO_WIN32_COVERAGE_UNSPEC;
}

static PangoCoverage *
pango_win32_font_entry_get_coverage (PangoWin32Face *face,
				     PangoLanguage  *lang)
{
  gint i = pango_win32_coverage_language_classify (lang);
  if (face->coverages[i])
    {
      pango_coverage_ref (face->coverages[i]);
      return face->coverages[i];
    }

  return NULL;
}

static void
pango_win32_font_entry_set_coverage (PangoWin32Face *face,
				     PangoCoverage  *coverage,
				     PangoLanguage  *lang)
{
  face->coverages[pango_win32_coverage_language_classify (lang)] = pango_coverage_ref (coverage);
}

static PangoCoverage *
pango_win32_font_get_coverage (PangoFont     *font,
			       PangoLanguage *lang)
{
  PangoCoverage *coverage;
  PangoWin32Font *win32font = (PangoWin32Font *)font;

  coverage = pango_win32_font_entry_get_coverage (win32font->win32face, lang);