tables.c

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/* HTML tables renderer */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdlib.h>
#include <string.h>

#include "elinks.h"

#include "document/html/parser/parse.h"
#include "document/html/parser/table.h"
#include "document/html/parser.h"
#include "document/html/renderer.h"
#include "document/html/tables.h"
#include "document/options.h"
#include "terminal/draw.h"
#include "util/color.h"
#include "util/conv.h"
#include "util/error.h"
#include "util/memory.h"
#include "util/string.h"

/* Unsafe macros */
#include "document/html/internal.h"


struct table_frames {
	unsigned int top:1;
	unsigned int bottom:1;
	unsigned int left:1;
	unsigned int right:1;
};

static void
get_table_frames(struct table *table, struct table_frames *result)
{
	assert(table && result);

	if (table->border) {
		result->top = !!(table->frame & TABLE_FRAME_ABOVE);
		result->bottom = !!(table->frame & TABLE_FRAME_BELOW);
		result->left = !!(table->frame & TABLE_FRAME_LHS);
		result->right = !!(table->frame & TABLE_FRAME_RHS);
	} else {
		memset(result, 0, sizeof(*result));
	}
}

/* Distance of the table from the left margin. */
static int
get_table_indent(struct html_context *html_context, struct table *table)
{
	int width = par_format.width - table->real_width;
	int indent;

	switch (table->align) {
	case ALIGN_CENTER:
		indent = (width + par_format.leftmargin - par_format.rightmargin) / 2;
		break;

	case ALIGN_RIGHT:
		indent = width - par_format.rightmargin;
		break;

	case ALIGN_LEFT:
	case ALIGN_JUSTIFY:
	default:
		indent = par_format.leftmargin;
	}

	/* Don't use int_bounds(&x, 0, width) here,
	 * width may be < 0. --Zas */
	if (indent > width) indent = width;
	if (indent < 0) indent = 0;

	return indent;
}

static inline struct part *
format_cell(struct html_context *html_context, struct table *table,
            struct table_cell *cell, struct document *document,
            int x, int y, int width)
{
	if (document) {
		x += table->part->box.x;
		y += table->part->box.y;
	}

	return format_html_part(html_context, cell->start, cell->end,
				cell->align, table->cellpadding, width,
	                        document, x, y, NULL, cell->link_num);
}

static inline void
get_cell_width(struct html_context *html_context,
	       unsigned char *start, unsigned char *end,
	       int cellpadding, int width,
	       int a, int *min, int *max,
	       int link_num, int *new_link_num)
{
	struct part *part;

	if (min) *min = -1;
	if (max) *max = -1;
	if (new_link_num) *new_link_num = link_num;

	part = format_html_part(html_context, start, end, ALIGN_LEFT,
				cellpadding, width, NULL,
				!!a, !!a, NULL, link_num);
	if (!part) return;

	if (min) *min = part->box.width;
	if (max) *max = part->max_width;
	if (new_link_num) *new_link_num = part->link_num;

	if (min && max) {
		assertm(*min <= *max, "get_cell_width: %d > %d", *min, *max);
	}

	mem_free(part);
}

static void
get_cell_widths(struct html_context *html_context, struct table *table)
{
	int link_num = table->part->link_num;

	if (!html_context->options->table_order) {
		int col, row;

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

				if (!cell->start) continue;
				cell->link_num = link_num;
				get_cell_width(html_context, cell->start,
					       cell->end, table->cellpadding,
					       0, 0, &cell->min_width,
					       &cell->max_width,
					       link_num, &link_num);
			}
	} else {
		int col, row;

		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;
				cell->link_num = link_num;
				get_cell_width(html_context, cell->start,
					       cell->end, table->cellpadding,
					       0, 0, &cell->min_width,
					       &cell->max_width,
					       link_num, &link_num);
			}
	}

	table->link_num = link_num;
}

static inline void
distribute_values(int *values, int count, int wanted, int *limits)
{
	int i;
	int sum = 0, d, r, t;

	for (i = 0; i < count; i++) sum += values[i];
	if (sum >= wanted) return;

again:
	t = wanted - sum;
	d = t / count;
	r = t % count;
	wanted = 0;

	if (limits) {
		for (i = 0; i < count; i++) {
			int delta;

			values[i] += d + (i < r);

			delta = values[i] - limits[i];
			if (delta > 0) {
				wanted += delta;
				values[i] = limits[i];
			}
		}
	} else {
		for (i = 0; i < count; i++) {
			values[i] += d + (i < r);
		}
	}

	if (wanted) {
		assertm(limits, "bug in distribute_values()");
		limits = NULL;
		sum = 0;
		goto again;
	}
}


/* Returns: -1 none, 0, space, 1 line, 2 double */
static inline int
get_vline_width(struct table *table, int col)
{
	int width = 0;

	if (!col) return -1;

	if (table->rules == TABLE_RULE_COLS || table->rules == TABLE_RULE_ALL)
		width = table->cellspacing;
	else if (table->rules == TABLE_RULE_GROUPS)
		width = (col < table->columns_count && table->columns[col].group);

	if (!width && table->cellpadding) width = -1;

	return width;
}

static int
get_hline_width(struct table *table, int row)
{
	if (!row) return -1;

	if (table->rules == TABLE_RULE_ROWS || table->rules == TABLE_RULE_ALL) {
		if (table->cellspacing || table->vcellpadding)
			return table->cellspacing;
		return -1;

	} else if (table->rules == TABLE_RULE_GROUPS) {
		int col;

		for (col = 0; col < table->cols; col++)
			if (CELL(table, col, row)->is_group) {
				if (table->cellspacing || table->vcellpadding)
					return table->cellspacing;
				return -1;
			}
	}

	return table->vcellpadding ? 0 : -1;
}

#define has_vline_width(table, col) (get_vline_width(table, col) >= 0)
#define has_hline_width(table, row) (get_hline_width(table, row) >= 0)


static int
get_column_widths(struct table *table)
{
	int colspan;

	if (!table->cols) return -1; /* prevents calloc(0, ...) calls */

	if (!table->min_cols_widths) {
		table->min_cols_widths = mem_calloc(table->cols, sizeof(*table->min_cols_widths));
		if (!table->min_cols_widths) return -1;
	}

	if (!table->max_cols_widths) {
		table->max_cols_widths = mem_calloc(table->cols, sizeof(*table->max_cols_widths));
		if (!table->max_cols_widths) {
			mem_free_set(&table->min_cols_widths, NULL);
			return -1;
		}
	}

	if (!table->cols_widths) {
		table->cols_widths = mem_calloc(table->cols, sizeof(*table->cols_widths));
		if (!table->cols_widths) {
			mem_free_set(&table->min_cols_widths, NULL);
			mem_free_set(&table->max_cols_widths, NULL);
			return -1;
		}
	}

	colspan = 1;
	do {
		int col, row;
		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->is_spanned || !cell->is_used) continue;

			assertm(cell->colspan + col <= table->cols, "colspan out of table");
			if_assert_failed return -1;

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

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

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

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

				for (k = 0; k < colspan; k++) {
					int tmp = col + k;

					int_lower_bound(&table->max_cols_widths[tmp],
							table->min_cols_widths[tmp]);
				}

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

	return 0;
}

static void
get_table_width(struct table *table)
{
	struct table_frames table_frames;
	int min = 0;
	int max = 0;
	int col;

	for (col = 0; col < table->cols; col++) {
		int vl = has_vline_width(table, col);

		min += vl + table->min_cols_widths[col];
		max += vl + table->max_cols_widths[col];
		if (table->cols_x[col] > table->max_cols_widths[col])
			max += table->cols_x[col];
	}

	get_table_frames(table, &table_frames);

	table->min_width = min + table_frames.left + table_frames.right;
	table->max_width = max + table_frames.left + table_frames.right;

	assertm(min <= max, "min(%d) > max(%d)", min, max);
	/* XXX: Recovery path? --pasky */
}


/* Initialize @width and @max_width arrays depending on the @stretch_method */
static inline int
apply_stretch_method(struct table *table, int widths[], int max_widths[],
		     int stretch_method, int max_cols_width)
{
	int col, total_width = 0;

	for (col = 0; col < table->cols; col++) {
		switch (stretch_method) {
		case 0:
			if (table->cols_widths[col] >= table->cols_x[col])
				break;

			widths[col] = 1;
			max_widths[col] = int_min(table->cols_x[col],
						  table->max_cols_widths[col])
					  - table->cols_widths[col];
			if (max_widths[col] <= 0) widths[col] = 0;
			break;
		case 1:
			if (table->cols_x[col] > WIDTH_RELATIVE)
				break;

			widths[col] = WIDTH_RELATIVE - table->cols_x[col];
			max_widths[col] = table->max_cols_widths[col]
					  - table->cols_widths[col];
			if (max_widths[col] <= 0) widths[col] = 0;
			break;
		case 2:
			if (table->cols_x[col] != WIDTH_AUTO)
				break;
			/* Fall-through */
		case 3:
			if (table->cols_widths[col] >= table->max_cols_widths[col])
				break;
			max_widths[col] = table->max_cols_widths[col]
					  - table->cols_widths[col];
			if (max_cols_width) {
				widths[col] = 5 + table->max_cols_widths[col] * 10 / max_cols_width;
			} else {
				widths[col] = 1;
			}
			break;
		case 4:
			if (table->cols_x[col] < 0)
				break;
			widths[col] = 1;
			max_widths[col] = table->cols_x[col]
					  - table->cols_widths[col];
			if (max_widths[col] <= 0) widths[col] = 0;
			break;
		case 5:
			if (table->cols_x[col] >= 0)
				break;
			if (table->cols_x[col] <= WIDTH_RELATIVE) {
				widths[col] = WIDTH_RELATIVE - table->cols_x[col];
			} else {
				widths[col] = 1;
			}
			max_widths[col] = INT_MAX;
			break;
		case 6:
			widths[col] = 1;
			max_widths[col] = INT_MAX;
			break;
		default:
			return -1;
		}

		total_width += widths[col];
	}

	return total_width;
}

/* Stretches the table columns by distributed the @spare_width among them.
 * Returns how much of @spare_width was actually distributed. */
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;