tables.c

一个很有名的浏览器

static inline int
stretch_columns(struct table *table, int widths[], int max_widths[],
		int spare_width, int total_width)
{
	int total_spare_width = spare_width;

	while (spare_width) {
		int stretch_width = 0;
		int stretch_col = -1;
		int col;

		for (col = 0; col < table->cols; col++) {
			int col_spare_width;

			if (!widths[col])
				continue;

			col_spare_width = total_spare_width * widths[col] / total_width;
			int_bounds(&col_spare_width, 1, max_widths[col]);

			if (col_spare_width > stretch_width) {
				stretch_width = col_spare_width;
				stretch_col = col;
			}
		}

		/* Got stretch column? */
		if (stretch_col == -1)
			break;

		/* Mark the column as visited */
		widths[stretch_col] = 0;

		if (stretch_width > spare_width)
			stretch_width = spare_width;
		assertm(stretch_width >= 0, "shrinking cell");

		table->cols_widths[stretch_col] += stretch_width;
		spare_width -= stretch_width;
	}

	return total_spare_width - spare_width;
}

/* This function distributes space evenly between @table columns so that it
 * stretches to @width. */
static void
distribute_widths(struct table *table, int width)
{
	int col;
	int spare_width = width - table->min_width;
	int stretch_method = 0;
	int *widths, *max_widths;
	int max_cols_width = 0;
	int cols_array_size;

	if (!table->cols)
		return;

	assertm(spare_width >= 0, "too small width %d, required %d",
		width, table->min_width);

	for (col = 0; col < table->cols; col++)
		int_lower_bound(&max_cols_width, table->max_cols_widths[col]);

	cols_array_size = table->cols * sizeof(*table->cols_widths);
	memcpy(table->cols_widths, table->min_cols_widths, cols_array_size);
	table->real_width = width;

	widths = fmem_alloc(cols_array_size);
	if (!widths) return;

	max_widths = fmem_alloc(cols_array_size);
	if (!max_widths) goto free_widths;

	while (spare_width) {
		int stretched, total_width;

		memset(widths, 0, cols_array_size);
		memset(max_widths, 0, cols_array_size);

		total_width = apply_stretch_method(table, widths, max_widths, stretch_method, max_cols_width);
		assertm(total_width != -1, "Could not expand table");
		if_assert_failed break;

		if (!total_width) {
			stretch_method++;
			continue;
		}

		stretched = stretch_columns(table, widths, max_widths, spare_width, total_width);
		if (!stretched)
			stretch_method++;
		else
			spare_width -= stretched;
	}

	fmem_free(max_widths);
free_widths:
	fmem_free(widths);
}


static int
get_table_cellpadding(struct table *table)
{
	struct part *part = table->part;
	int cpd_pass = 0, cpd_width = 0, cpd_last = table->cellpadding;
	int margins = par_format.leftmargin + par_format.rightmargin;

again:
	get_cell_widths(table);
	if (get_column_widths(table)) return -1;

	get_table_width(table);

	if (!part->document && !part->box.x) {
		if (!table->full_width)
			int_upper_bound(&table->max_width, table->width);
		int_lower_bound(&table->max_width, table->min_width);

		int_lower_bound(&part->max_width, table->max_width + margins);
		int_lower_bound(&part->box.width, table->min_width + margins);

		return -1;
	}

	if (!cpd_pass && table->min_width > table->width && table->cellpadding) {
		table->cellpadding = 0;
		cpd_pass = 1;
		cpd_width = table->min_width;
		goto again;
	}
	if (cpd_pass == 1 && table->min_width > cpd_width) {
		table->cellpadding = cpd_last;
		cpd_pass = 2;
		goto again;
	}

	return 0;
}



#ifdef HTML_TABLE_2ND_PASS /* This is by default ON! (<setup.h>) */
static void
check_table_widths(struct table *table)
{
	int col, row;
	int colspan;
	int width, new_width;
	int max, max_index = 0; /* go away, warning! */
	int *widths = mem_calloc(table->cols, sizeof(*widths));

	if (!widths) return;

	for (row = 0; row < table->rows; row++) for (col = 0; col < table->cols; col++) {
		struct table_cell *cell = CELL(table, col, row);
		int k, p = 0;

		if (!cell->start) continue;

		for (k = 0; k < cell->colspan; k++) {
			p += table->cols_widths[col + k] +
			     (k && has_vline_width(table, col + k));
		}

		get_cell_width(cell->start, cell->end, table->cellpadding, p, 1, &cell->width,
			       NULL, cell->link_num, NULL);

		int_upper_bound(&cell->width, p);
	}

	colspan = 1;
	do {
		int new_colspan = INT_MAX;

		for (col = 0; col < table->cols; col++) for (row = 0; row < table->rows; row++) {
			struct table_cell *cell = CELL(table, col, row);

			if (!cell->start) continue;

			assertm(cell->colspan + col <= table->cols, "colspan out of table");
			if_assert_failed goto end;

			if (cell->colspan == colspan) {
				int k, p = 0;

				for (k = 1; k < colspan; k++)
					p += has_vline_width(table, col + k);

				distribute_values(&widths[col],
						  colspan,
						  cell->width - p,
						  &table->max_cols_widths[col]);

			} else if (cell->colspan > colspan
				   && cell->colspan < new_colspan) {
				new_colspan = cell->colspan;
			}
		}
		colspan = new_colspan;
	} while (colspan != INT_MAX);

	width = new_width = 0;
	for (col = 0; col < table->cols; col++) {
		width += table->cols_widths[col];
		new_width += widths[col];
	}

	if (new_width > width) {
		/* INTERNAL("new width(%d) is larger than previous(%d)", new_width, width); */
		goto end;
	}

	max = -1;
	for (col = 0; col < table->cols; col++)
		if (table->max_cols_widths[col] > max) {
			max = table->max_cols_widths[col];
			max_index = col;
		}

	if (max != -1) {
		widths[max_index] += width - new_width;
		if (widths[max_index] <= table->max_cols_widths[max_index]) {
			mem_free(table->cols_widths);
			table->cols_widths = widths;
			return;
		}
	}

end:
	mem_free(widths);
}
#endif


static void
check_table_height(struct table *table, struct table_frames *frames, int y)
{
#ifndef CONFIG_FASTMEM
	/* XXX: Cannot we simply use the @yp value we just calculated
	 * in draw_table_cells()? --pasky */
	int old_height = table->real_height + table->part->cy;
	int our_height = frames->top + y + frames->bottom + table->caption_height;
	int row;

	/* XXX: We cannot use get_table_real_height() because we are
	 * looking one row ahead - which is completely arcane to me.
	 * It makes a difference only when a table uses ruler="groups"
	 * and has non-zero cellspacing or vcellpadding. --pasky */

	for (row = 0; row < table->rows; row++) {
		our_height += table->rows_heights[row] +
			      (row < table->rows - 1 &&
			       has_hline_width(table, row + 1));
	}

	assertm(old_height == our_height, "size not matching! %d vs %d",
		old_height, our_height);
#endif
}

static int
get_table_caption_height(struct table *table)
{
	unsigned char *start = table->caption.start;
	unsigned char *end = table->caption.end;
	struct part *part;

	if (!start || !end) return 0;

	while (start < end && isspace(*start))
		start++;

	while (start < end && isspace(end[-1]))
		end--;

	if (start >= end) return 0;

	part = format_html_part(start, end, table->align,
		0, table->real_width, NULL, 0, 0,
		NULL, table->link_num);

	if (!part) {
		return 0;

	} else {
		int height = part->box.height;
		mem_free(part);

		return height;
	}
}

static int
get_table_real_height(struct table *table)
{
	struct table_frames table_frames;
	int height;
	int row;

	get_table_frames(table, &table_frames);

	height = table_frames.top + table_frames.bottom;
	height += table->caption_height;
	for (row = 0; row < table->rows; row++) {
		height += table->rows_heights[row];
		if (row && has_hline_width(table, row))
			height++;
	}

	return height;
}

static void
get_table_heights(struct table *table)
{
	int rowspan;
	int col, row;

	table->caption_height = get_table_caption_height(table);

	for (row = 0; row < table->rows; row++) {
		for (col = 0; col < table->cols; col++) {
			struct table_cell *cell = CELL(table, col, row);
			struct part *part;
			int width = 0, sp;

			if (!cell->is_used || cell->is_spanned) continue;

			for (sp = 0; sp < cell->colspan; sp++) {
				width += table->cols_widths[col + sp] +
					 (sp < cell->colspan - 1 &&
					  has_vline_width(table, col + sp + 1));
			}

			part = format_cell(table, cell, NULL, 2, 2, width);
			if (!part) return;

			cell->height = part->box.height;
			/* DBG("%d, %d.", width, cell->height); */
			mem_free(part);
		}
	}

	rowspan = 1;
	do {
		int new_rowspan = INT_MAX;

		for (row = 0; row < table->rows; row++) {
			for (col = 0; col < table->cols; col++) {
				struct table_cell *cell = CELL(table, col, row);

				if (!cell->is_used || cell->is_spanned) continue;

				if (cell->rowspan == rowspan) {
					int k, p = 0;

					for (k = 1; k < rowspan; k++)
						p += has_hline_width(table, row + k);

					distribute_values(&table->rows_heights[row],
							  rowspan,
							  cell->height - p,
							  NULL);

				} else if (cell->rowspan > rowspan &&
					   cell->rowspan < new_rowspan) {
					new_rowspan = cell->rowspan;
				}

			}
		}
		rowspan = new_rowspan;
	} while (rowspan != INT_MAX);

	table->real_height = get_table_real_height(table);
}

static void
draw_table_cell(struct table *table, int col, int row, int x, int y)
{
	struct table_cell *cell = CELL(table, col, row);
	struct document *document = table->part->document;
	struct part *part;
	int width = 0;
	int height = 0;
	int s, tmpy = y;
	struct html_element *state;

	if (!cell->start) return;

	for (s = 0; s < cell->colspan; s++) {
		width += table->cols_widths[col + s] +
			(s < cell->colspan - 1 &&
			 has_vline_width(table, col + s + 1));
	}

	for (s = 0; s < cell->rowspan; s++) {
		height += table->rows_heights[row + s] +
			(s < cell->rowspan - 1 &&
			 has_hline_width(table, row + s + 1));
	}

	state = init_html_parser_state(ELEMENT_DONT_KILL, cell->align, 0, 0);

	if (cell->is_header) format.style.attr |= AT_BOLD;

	format.style.bg = cell->bgcolor;
	par_format.bgcolor = cell->bgcolor;

	if (cell->valign == VALIGN_MIDDLE)
		tmpy += (height - cell->height) / 2;
	else if (cell->valign == VALIGN_BOTTOM)
		tmpy += (height - cell->height);

	part = format_cell(table, cell, document, x, tmpy, width);
	if (part) {
		/* The cell content doesn't necessarily fill out the whole cell
		 * height so use the calculated @height because it is an upper
		 * bound. */
		assert(height >= cell->height);

		/* The line expansion draws the _remaining_ background color of
		 * both untouched lines and lines that doesn't stretch the