dw_page.c

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/*
 * Standard Dw function
 */
static void Dw_page_add (DwContainer *container,
                         DwWidget *widget)
{
   /* todo */
}


/*
 * Standard Dw function
 */
static void Dw_page_remove (DwContainer *container,
                            DwWidget *widget)
{
   /* todo */
}


/*
 * Standard Dw function
 */
static void Dw_page_forall (DwContainer *container,
                            DwCallback callback,
                            gpointer callback_data)
{
   DwPage *page;
   int word_index;
   DwPageWord *word;

   page = DW_PAGE (container);

   for (word_index = 0; word_index < page->num_words; word_index++) {
      word = &page->words[word_index];

      if (word->content.type == DW_CONTENT_WIDGET)
         (*callback) (word->content.data.widget, callback_data);
   }
}


/*
 * ...
 *
 * avail_line is passed from Dw_page_real_word_wrap, to avoid calculating
 * it twice.
 */
static void Dw_page_justify_line (DwPage *page, DwPageLine *line,
                                  gint32 avail_width)
{
   /* To avoid rounding errors, the calculation is based on accumulated
    * values (*_cum). */
   gint i;
   gint32 orig_space_sum, orig_space_cum;
   gint32 eff_space_diff_cum, last_eff_space_diff_cum;
   gint32 diff;

   diff = avail_width - page->last_line_width;
   if (diff > 0) {
      orig_space_sum = 0;
      for (i = line->first_word; i < line->last_word - 1; i++)
         orig_space_sum += page->words[i].orig_space;

      orig_space_cum = 0;
      last_eff_space_diff_cum = 0;
      for (i = line->first_word; i < line->last_word - 1; i++) {
         orig_space_cum += page->words[i].orig_space;

         if (orig_space_cum == 0)
            eff_space_diff_cum = last_eff_space_diff_cum;
         else
            eff_space_diff_cum = diff * orig_space_cum / orig_space_sum;

         page->words[i].eff_space = page->words[i].orig_space +
            (eff_space_diff_cum - last_eff_space_diff_cum);
         DBG_OBJ_ARRSET_NUM (page, "words.%d.eff_space", i,
                             page->words[i].eff_space);

         last_eff_space_diff_cum = eff_space_diff_cum;
      }
   }
}

/*
 * ...
 */
static void Dw_page_add_line (DwPage *page, gint word_ind, gboolean new_par)
{
   DwPageLine *last_line, *plast_line;

   DBG_MSG (page, "wrap", 0, "Dw_page_add_line");
   DBG_MSG_START (page);

   page->num_lines++;
   a_List_add (page->lines, page->num_lines, page->num_lines_max);
   DBG_OBJ_SET_NUM(page, "num_lines", page->num_lines);

   DEBUG_MSG (DEBUG_REWRAP_LEVEL, "--- new line %d in %p, with word %d of %d"
              "\n", page->num_lines - 1, page, word_ind, page->num_words);

   last_line = &page->lines[page->num_lines - 1];

   if (page->num_lines == 1)
      plast_line = NULL;
   else
      plast_line = &page->lines[page->num_lines - 2];

   if (plast_line) {
      /* second or more lines: copy values of last line */
      last_line->top =
         plast_line->top + plast_line->ascent +
         plast_line->descent + plast_line->break_space;
      last_line->max_line_width = plast_line->max_line_width;
      last_line->max_word_min = plast_line->max_word_min;
      last_line->max_par_max = plast_line->max_par_max;
      last_line->par_min = plast_line->par_min;
      last_line->par_max = plast_line->par_max;
   } else {
      /* first line: initialize values */
      last_line->top = 0;
      last_line->max_line_width = page->line1_offset_eff;
      last_line->max_word_min = 0;
      last_line->max_par_max = 0;
      last_line->par_min =  page->line1_offset_eff;
      last_line->par_max =  page->line1_offset_eff;
   }

   DBG_OBJ_ARRSET_NUM (page, "lines.%d.top", page->num_lines - 1,
                       last_line->top);
   DBG_OBJ_ARRSET_NUM (page, "lines.%d.max_line_width", page->num_lines - 1,
                       last_line->max_line_width);
   DBG_OBJ_ARRSET_NUM (page, "lines.%d.max_word_min", page->num_lines - 1,
                       last_line->max_word_min);
   DBG_OBJ_ARRSET_NUM (page, "lines.%d.max_par_max", page->num_lines - 1,
                       last_line->max_par_max);
   DBG_OBJ_ARRSET_NUM (page, "lines.%d.par_min", page->num_lines - 1,
                       last_line->par_min);
   DBG_OBJ_ARRSET_NUM (page, "lines.%d.par_max", page->num_lines - 1,
                       last_line->par_max);

   last_line->first_word = word_ind;
   last_line->ascent = 0;
   last_line->descent = 0;
   last_line->margin_descent = 0;
   last_line->break_space = 0;
   last_line->left_offset = 0;

   DBG_OBJ_ARRSET_NUM (page, "lines.%d.ascent", page->num_lines - 1,
                       last_line->ascent);
   DBG_OBJ_ARRSET_NUM (page, "lines.%d.descent", page->num_lines - 1,
                       last_line->descent);

   /* update values in line */
   last_line->max_line_width =
      MAX (last_line->max_line_width, page->last_line_width);

   if (page->num_lines > 1)
      page->last_line_width = 0;
   else
      page->last_line_width = page->line1_offset_eff;

   if (new_par) {
      last_line->max_par_max =
         MAX (last_line->max_par_max, page->last_line_par_max);
      DBG_OBJ_ARRSET_NUM (page, "lines.%d.max_par_max", page->num_lines - 1,
                          last_line->max_par_max);

      if (page->num_lines > 1) {
         last_line->par_min = 0;
         last_line->par_max = 0;
      } else {
         last_line->par_min = page->line1_offset_eff;
         last_line->par_max = page->line1_offset_eff;
      }
      page->last_line_par_min = 0;
      page->last_line_par_max = 0;

      DBG_OBJ_SET_NUM(page, "last_line_par_min", page->last_line_par_min);
      DBG_OBJ_SET_NUM(page, "last_line_par_max", page->last_line_par_max);
   }

   last_line->par_min = page->last_line_par_min;
   last_line->par_max = page->last_line_par_max;

   DBG_OBJ_ARRSET_NUM (page, "lines.%d.par_min", page->num_lines - 1,
                       last_line->par_min);
   DBG_OBJ_ARRSET_NUM (page, "lines.%d.par_max", page->num_lines - 1,
                       last_line->par_max);

   DBG_MSG_END (page);
}


/*
 * This function is called in two cases: (i) when a word is added (by
 * Dw_page_add_word), and (ii) when a page has to be (partially)
 * rewrapped. It does word wrap, and adds new lines, if necesary.
 */
static void Dw_page_real_word_wrap (DwPage *page, gint word_ind)
{
   DwPageLine *last_line;
   DwPageWord *word, *prev_word;
   gint32 avail_width, last_space, left_offset;
   gboolean new_line = FALSE, new_par = FALSE;
   DwWidget *widget = DW_WIDGET (page);
   DwExtremes word_extremes;

   DBG_MSGF (page, "wrap", 0, "Dw_page_real_word_wrap (%d): %s, width = %d",
             word_ind, a_Dw_content_html (&page->words[word_ind].content),
             page->words[word_ind].size.width);
   DBG_MSG_START (page);

   avail_width =
      page->avail_width - p_Dw_style_box_diff_width (widget->style)
      - page->inner_padding;
   if (prefs.limit_text_width &&
       avail_width > widget->viewport->allocation.width - 10)
      avail_width = widget->viewport->allocation.width - 10;

   word = &page->words[word_ind];

   if (page->num_lines == 0) {
      DBG_MSG (page, "wrap", 0, "first line");
      new_line = TRUE;
      new_par = TRUE;
      last_line = NULL;
   } else {
      last_line = &page->lines[page->num_lines - 1];

      if (page->num_words > 0) {
         prev_word = &page->words[word_ind - 1];
         if (prev_word->content.type == DW_CONTENT_BREAK) {
            DBG_MSG (page, "wrap", 0, "after a break");
            /* previous word is a break */
            new_line = TRUE;
            new_par = TRUE;
         } else if (word->style->white_space != DW_STYLE_WHITE_SPACE_NORMAL) {
            DBG_MSGF (page, "wrap", 0, "no wrap (white_space = %d)",
                      word->style->white_space);
            new_line = FALSE;
            new_par = FALSE;
         } else {
            if (last_line->first_word != word_ind) {
               /* Does new word fit into the last line? */
               DBG_MSGF (page, "wrap", 0,
                         "word %d (%s) fits? (%d + %d + %d &lt;= %d)...",
                         word_ind, a_Dw_content_html (&word->content),
                         page->last_line_width, prev_word->orig_space,
                         word->size.width, avail_width);
               new_line = (page->last_line_width + prev_word->orig_space
                           + word->size.width > avail_width);
               DBG_MSGF (page, "wrap", 0, "... %s.",
                         new_line ? "No" : "Yes");
            }
         }
      }
   }

   /* Has sometimes the wrong value. */
   word->eff_space = word->orig_space;
   DBG_OBJ_ARRSET_NUM (page, "words.%d.eff_space", word_ind, word->eff_space);

   /* Test, whether line1_offset can be used. */
   if (word_ind == 0) {
      if (page->ignore_line1_offset_sometimes) {
         if (page->line1_offset + word->size.width > avail_width)
            page->line1_offset_eff = 0;
         else
            page->line1_offset_eff = page->line1_offset;
      } else
         page->line1_offset_eff = page->line1_offset;
   }

   if (last_line != NULL && new_line && !new_par &&
       word->style->text_align == DW_STYLE_TEXT_ALIGN_JUSTIFY)
      Dw_page_justify_line (page, last_line, avail_width);

   if (new_line) {
      Dw_page_add_line (page, word_ind, new_par);
      last_line = &page->lines[page->num_lines - 1];
   }

   last_line->last_word = word_ind + 1;
   last_line->ascent = MAX (last_line->ascent, word->size.ascent);
   last_line->descent = MAX (last_line->descent, word->size.descent);

   DBG_OBJ_ARRSET_NUM (page, "lines.%d.ascent", page->num_lines - 1,
                       last_line->ascent);
   DBG_OBJ_ARRSET_NUM (page, "lines.%d.descent", page->num_lines - 1,
                       last_line->descent);

   if (word->content.type == DW_CONTENT_WIDGET) {
      last_line->margin_descent =
         MAX (last_line->margin_descent,
              word->size.descent +
              word->content.data.widget->style->margin.bottom);

      DBG_OBJ_ARRSET_NUM (page, "lines.%d.descent", page->num_lines - 1,
                          last_line->descent);

      /* If the widget is not in the first line of the paragraph, its top
       * margin may make the line higher.
       */
      if (page->num_lines > 1) {
         /* Here, we know already what the break and the bottom margin
          * contributed to the space before this line.
          */
         last_line->ascent =
            MAX (last_line->ascent,
                 word->size.ascent
                 + word->content.data.widget->style->margin.top);

         DBG_OBJ_ARRSET_NUM (page, "lines.%d.ascent", page->num_lines - 1,
                             last_line->ascent);
      }
   } else
      last_line->margin_descent =
         MAX (last_line->margin_descent, last_line->descent);

   Dw_page_get_word_extremes (word, &word_extremes);
   last_space = (word_ind > 0) ? page->words[word_ind - 1].orig_space : 0;

   if (word->content.type == DW_CONTENT_BREAK)
      last_line->break_space =
         MAX3 (word->content.data.break_space,
               last_line->margin_descent - last_line->descent,
               last_line->break_space);

   page->last_line_width += word->size.width;
   if (!new_line)
      page->last_line_width += last_space;

   page->last_line_par_min += word_extremes.max_width;
   page->last_line_par_max += word_extremes.max_width;
   if (!new_par) {
      page->last_line_par_min += last_space;
      page->last_line_par_max += last_space;
   }

   if (word->style->white_space != DW_STYLE_WHITE_SPACE_NORMAL) {
      last_line->par_min += word_extremes.min_width + last_space;
      /* This may also increase the accumulated minimum word width.  */
      last_line->max_word_min =
         MAX (last_line->max_word_min, last_line->par_min);
      /* NOTE: Most code relies on that all values of nowrap are equal for all
       * words within one line. */
   } else
      /* Simple case. */
      last_line->max_word_min =
         MAX (last_line->max_word_min, word_extremes.min_width);

   DBG_OBJ_SET_NUM(page, "last_line_par_min", page->last_line_par_min);
   DBG_OBJ_SET_NUM(page, "last_line_par_max", page->last_line_par_max);
   DBG_OBJ_ARRSET_NUM (page, "lines.%d.par_min", page->num_lines - 1,
                       last_line->par_min);
   DBG_OBJ_ARRSET_NUM (page, "lines.%d.par_max", page->num_lines - 1,
                       last_line->par_max);
   DBG_OBJ_ARRSET_NUM (page, "lines.%d.max_word_min", page->num_lines - 1,
                       last_line->max_word_min);

   /* Finally, justify the line. Breaks are ignored, since the HTML
    * parser sometimes assignes the wrong style to them. (todo: ) */
   if (word->content.type != DW_CONTENT_BREAK) {
      switch (word->style->text_align) {
      case DW_STYLE_TEXT_ALIGN_LEFT: