netsurf/content/handlers/html/box_inspect.c
2020-05-02 20:47:53 +01:00

886 lines
22 KiB
C

/*
* Copyright 2008 Michael Drake <tlsa@netsurf-browser.org>
* Copyright 2020 Vincent Sanders <vince@netsurf-browser.org>
*
* This file is part of NetSurf, http://www.netsurf-browser.org/
*
* NetSurf is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* NetSurf is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* \file
* implementation of box tree inspection.
*/
#include <stdio.h>
#include <dom/dom.h>
#include "utils/nsurl.h"
#include "utils/errors.h"
#include "netsurf/types.h"
#include "netsurf/content.h"
#include "netsurf/mouse.h"
#include "css/utils.h"
#include "css/dump.h"
#include "desktop/scrollbar.h"
#include "html/private.h"
#include "html/box.h"
#include "html/box_inspect.h"
/**
* Direction to move in a box-tree walk
*/
enum box_walk_dir {
BOX_WALK_CHILDREN,
BOX_WALK_PARENT,
BOX_WALK_NEXT_SIBLING,
BOX_WALK_FLOAT_CHILDREN,
BOX_WALK_NEXT_FLOAT_SIBLING,
BOX_WALK_FLOAT_CONTAINER
};
#define box_is_float(box) (box->type == BOX_FLOAT_LEFT || \
box->type == BOX_FLOAT_RIGHT)
/**
* Determine if a point lies within a box.
*
* \param[in] len_ctx CSS length conversion context to use.
* \param[in] box Box to consider
* \param[in] x Coordinate relative to box
* \param[in] y Coordinate relative to box
* \param[out] physically If function returning true, physically is set true
* iff point is within the box's physical dimensions and
* false if the point is not within the box's physical
* dimensions but is in the area defined by the box's
* descendants. If function returns false, physically
* is undefined.
* \return true if the point is within the box or a descendant box
*
* This is a helper function for box_at_point().
*/
static bool
box_contains_point(const nscss_len_ctx *len_ctx,
const struct box *box,
int x,
int y,
bool *physically)
{
css_computed_clip_rect css_rect;
if (box->style != NULL &&
css_computed_position(box->style) == CSS_POSITION_ABSOLUTE &&
css_computed_clip(box->style, &css_rect) == CSS_CLIP_RECT) {
/* We have an absolutly positioned box with a clip rect */
struct rect r = {
.x0 = box->border[LEFT].width,
.y0 = box->border[TOP].width,
.x1 = box->padding[LEFT] + box->width +
box->border[RIGHT].width +
box->padding[RIGHT],
.y1 = box->padding[TOP] + box->height +
box->border[BOTTOM].width +
box->padding[BOTTOM]
};
if (x >= r.x0 && x < r.x1 && y >= r.y0 && y < r.y1) {
*physically = true;
} else {
*physically = false;
}
/* Adjust rect to css clip region */
if (css_rect.left_auto == false) {
r.x0 += FIXTOINT(nscss_len2px(len_ctx,
css_rect.left,
css_rect.lunit,
box->style));
}
if (css_rect.top_auto == false) {
r.y0 += FIXTOINT(nscss_len2px(len_ctx,
css_rect.top,
css_rect.tunit,
box->style));
}
if (css_rect.right_auto == false) {
r.x1 = box->border[LEFT].width +
FIXTOINT(nscss_len2px(len_ctx,
css_rect.right,
css_rect.runit,
box->style));
}
if (css_rect.bottom_auto == false) {
r.y1 = box->border[TOP].width +
FIXTOINT(nscss_len2px(len_ctx,
css_rect.bottom,
css_rect.bunit,
box->style));
}
/* Test if point is in clipped box */
if (x >= r.x0 && x < r.x1 && y >= r.y0 && y < r.y1) {
/* inside clip area */
return true;
}
/* Not inside clip area */
return false;
}
if (x >= -box->border[LEFT].width &&
x < box->padding[LEFT] + box->width +
box->padding[RIGHT] + box->border[RIGHT].width &&
y >= -box->border[TOP].width &&
y < box->padding[TOP] + box->height +
box->padding[BOTTOM] + box->border[BOTTOM].width) {
*physically = true;
return true;
}
if (box->list_marker && box->list_marker->x - box->x <= x +
box->list_marker->border[LEFT].width &&
x < box->list_marker->x - box->x +
box->list_marker->padding[LEFT] +
box->list_marker->width +
box->list_marker->border[RIGHT].width +
box->list_marker->padding[RIGHT] &&
box->list_marker->y - box->y <= y +
box->list_marker->border[TOP].width &&
y < box->list_marker->y - box->y +
box->list_marker->padding[TOP] +
box->list_marker->height +
box->list_marker->border[BOTTOM].width +
box->list_marker->padding[BOTTOM]) {
*physically = true;
return true;
}
if ((box->style && css_computed_overflow_x(box->style) ==
CSS_OVERFLOW_VISIBLE) || !box->style) {
if (box->descendant_x0 <= x &&
x < box->descendant_x1) {
*physically = false;
return true;
}
}
if ((box->style && css_computed_overflow_y(box->style) ==
CSS_OVERFLOW_VISIBLE) || !box->style) {
if (box->descendant_y0 <= y &&
y < box->descendant_y1) {
*physically = false;
return true;
}
}
return false;
}
/**
* Move from box to next box in given direction, adjusting for box coord change
*
* \param b box to move from from
* \param dir direction to move in
* \param x box's global x-coord, updated to position of next box
* \param y box's global y-coord, updated to position of next box
*
* If no box can be found in given direction, NULL is returned.
*/
static inline struct box *
box_move_xy(struct box *b, enum box_walk_dir dir, int *x, int *y)
{
struct box *rb = NULL;
switch (dir) {
case BOX_WALK_CHILDREN:
b = b->children;
if (b == NULL)
break;
*x += b->x;
*y += b->y;
if (!box_is_float(b)) {
rb = b;
break;
}
/* fall through */
case BOX_WALK_NEXT_SIBLING:
do {
*x -= b->x;
*y -= b->y;
b = b->next;
if (b == NULL)
break;
*x += b->x;
*y += b->y;
} while (box_is_float(b));
rb = b;
break;
case BOX_WALK_PARENT:
*x -= b->x;
*y -= b->y;
rb = b->parent;
break;
case BOX_WALK_FLOAT_CHILDREN:
b = b->float_children;
if (b == NULL)
break;
*x += b->x;
*y += b->y;
rb = b;
break;
case BOX_WALK_NEXT_FLOAT_SIBLING:
*x -= b->x;
*y -= b->y;
b = b->next_float;
if (b == NULL)
break;
*x += b->x;
*y += b->y;
rb = b;
break;
case BOX_WALK_FLOAT_CONTAINER:
*x -= b->x;
*y -= b->y;
rb = b->float_container;
break;
default:
assert(0 && "Bad box walk type.");
}
return rb;
}
/**
* Itterator for walking to next box in interaction order
*
* \param b box to find next box from
* \param x box's global x-coord, updated to position of next box
* \param y box's global y-coord, updated to position of next box
* \param skip_children whether to skip box's children
*
* This walks to a boxes float children before its children. When walking
* children, floating boxes are skipped.
*/
static inline struct box *
box_next_xy(struct box *b, int *x, int *y, bool skip_children)
{
struct box *n;
int tx, ty;
assert(b != NULL);
if (skip_children) {
/* Caller is not interested in any kind of children */
goto skip_children;
}
tx = *x; ty = *y;
n = box_move_xy(b, BOX_WALK_FLOAT_CHILDREN, &tx, &ty);
if (n) {
/* Next node is float child */
*x = tx;
*y = ty;
return n;
}
done_float_children:
tx = *x; ty = *y;
n = box_move_xy(b, BOX_WALK_CHILDREN, &tx, &ty);
if (n) {
/* Next node is child */
*x = tx;
*y = ty;
return n;
}
skip_children:
tx = *x; ty = *y;
n = box_move_xy(b, BOX_WALK_NEXT_FLOAT_SIBLING, &tx, &ty);
if (n) {
/* Go to next float sibling */
*x = tx;
*y = ty;
return n;
}
if (box_is_float(b)) {
/* Done floats, but the float container may have children,
* or siblings, or ansestors with siblings. Change to
* float container and move past handling its float children.
*/
b = box_move_xy(b, BOX_WALK_FLOAT_CONTAINER, x, y);
goto done_float_children;
}
/* Go to next sibling, or nearest ancestor with next sibling. */
while (b) {
while (!b->next && b->parent) {
b = box_move_xy(b, BOX_WALK_PARENT, x, y);
if (box_is_float(b)) {
/* Go on to next float, if there is one */
goto skip_children;
}
}
if (!b->next) {
/* No more boxes */
return NULL;
}
tx = *x; ty = *y;
n = box_move_xy(b, BOX_WALK_NEXT_SIBLING, &tx, &ty);
if (n) {
/* Go to non-float (ancestor) sibling */
*x = tx;
*y = ty;
return n;
} else if (b->parent) {
b = box_move_xy(b, BOX_WALK_PARENT, x, y);
if (box_is_float(b)) {
/* Go on to next float, if there is one */
goto skip_children;
}
} else {
/* No more boxes */
return NULL;
}
}
assert(b != NULL);
return NULL;
}
/**
* Check whether box is nearer mouse coordinates than current nearest box
*
* \param box box to test
* \param bx position of box, in global document coordinates
* \param by position of box, in global document coordinates
* \param x mouse point, in global document coordinates
* \param y mouse point, in global document coordinates
* \param dir direction in which to search (-1 = above-left,
* +1 = below-right)
* \param nearest nearest text box found, or NULL if none
* updated if box is nearer than existing nearest
* \param tx position of text_box, in global document coordinates
* updated if box is nearer than existing nearest
* \param ty position of text_box, in global document coordinates
* updated if box is nearer than existing nearest
* \param nr_xd distance to nearest text box found
* updated if box is nearer than existing nearest
* \param nr_yd distance to nearest text box found
* updated if box is nearer than existing nearest
* \return true if mouse point is inside box
*/
static bool
box_nearer_text_box(struct box *box,
int bx, int by,
int x, int y,
int dir,
struct box **nearest,
int *tx, int *ty,
int *nr_xd, int *nr_yd)
{
int w = box->padding[LEFT] + box->width + box->padding[RIGHT];
int h = box->padding[TOP] + box->height + box->padding[BOTTOM];
int y1 = by + h;
int x1 = bx + w;
int yd = INT_MAX;
int xd = INT_MAX;
if (x >= bx && x1 > x && y >= by && y1 > y) {
*nearest = box;
*tx = bx;
*ty = by;
return true;
}
if (box->parent->list_marker != box) {
if (dir < 0) {
/* consider only those children (partly) above-left */
if (by <= y && bx < x) {
yd = y <= y1 ? 0 : y - y1;
xd = x <= x1 ? 0 : x - x1;
}
} else {
/* consider only those children (partly) below-right */
if (y1 > y && x1 > x) {
yd = y > by ? 0 : by - y;
xd = x > bx ? 0 : bx - x;
}
}
/* give y displacement precedence over x */
if (yd < *nr_yd || (yd == *nr_yd && xd <= *nr_xd)) {
*nr_yd = yd;
*nr_xd = xd;
*nearest = box;
*tx = bx;
*ty = by;
}
}
return false;
}
/**
* Pick the text box child of 'box' that is closest to and above-left
* (dir -ve) or below-right (dir +ve) of the point 'x,y'
*
* \param box parent box
* \param bx position of box, in global document coordinates
* \param by position of box, in global document coordinates
* \param fx position of float parent, in global document coordinates
* \param fy position of float parent, in global document coordinates
* \param x mouse point, in global document coordinates
* \param y mouse point, in global document coordinates
* \param dir direction in which to search (-1 = above-left,
* +1 = below-right)
* \param nearest nearest text box found, or NULL if none
* updated if a descendant of box is nearer than old nearest
* \param tx position of nearest, in global document coordinates
* updated if a descendant of box is nearer than old nearest
* \param ty position of nearest, in global document coordinates
* updated if a descendant of box is nearer than old nearest
* \param nr_xd distance to nearest text box found
* updated if a descendant of box is nearer than old nearest
* \param nr_yd distance to nearest text box found
* updated if a descendant of box is nearer than old nearest
* \return true if mouse point is inside text_box
*/
static bool
box_nearest_text_box(struct box *box,
int bx, int by,
int fx, int fy,
int x, int y,
int dir,
struct box **nearest,
int *tx, int *ty,
int *nr_xd, int *nr_yd)
{
struct box *child = box->children;
int c_bx, c_by;
int c_fx, c_fy;
bool in_box = false;
if (*nearest == NULL) {
*nr_xd = INT_MAX / 2; /* displacement of 'nearest so far' */
*nr_yd = INT_MAX / 2;
}
if (box->type == BOX_INLINE_CONTAINER) {
int bw = box->padding[LEFT] + box->width + box->padding[RIGHT];
int bh = box->padding[TOP] + box->height + box->padding[BOTTOM];
int b_y1 = by + bh;
int b_x1 = bx + bw;
if (x >= bx && b_x1 > x && y >= by && b_y1 > y) {
in_box = true;
}
}
while (child) {
if (child->type == BOX_FLOAT_LEFT ||
child->type == BOX_FLOAT_RIGHT) {
c_bx = fx + child->x -
scrollbar_get_offset(child->scroll_x);
c_by = fy + child->y -
scrollbar_get_offset(child->scroll_y);
} else {
c_bx = bx + child->x -
scrollbar_get_offset(child->scroll_x);
c_by = by + child->y -
scrollbar_get_offset(child->scroll_y);
}
if (child->float_children) {
c_fx = c_bx;
c_fy = c_by;
} else {
c_fx = fx;
c_fy = fy;
}
if (in_box && child->text && !child->object) {
if (box_nearer_text_box(child,
c_bx, c_by, x, y, dir, nearest,
tx, ty, nr_xd, nr_yd))
return true;
} else {
if (child->list_marker) {
if (box_nearer_text_box(
child->list_marker,
c_bx + child->list_marker->x,
c_by + child->list_marker->y,
x, y, dir, nearest,
tx, ty, nr_xd, nr_yd))
return true;
}
if (box_nearest_text_box(child, c_bx, c_by,
c_fx, c_fy,
x, y, dir, nearest, tx, ty,
nr_xd, nr_yd))
return true;
}
child = child->next;
}
return false;
}
/* Exported function documented in html/box.h */
void box_coords(struct box *box, int *x, int *y)
{
*x = box->x;
*y = box->y;
while (box->parent) {
if (box_is_float(box)) {
assert(box->float_container);
box = box->float_container;
} else {
box = box->parent;
}
*x += box->x - scrollbar_get_offset(box->scroll_x);
*y += box->y - scrollbar_get_offset(box->scroll_y);
}
}
/* Exported function documented in html/box.h */
void box_bounds(struct box *box, struct rect *r)
{
int width, height;
box_coords(box, &r->x0, &r->y0);
width = box->padding[LEFT] + box->width + box->padding[RIGHT];
height = box->padding[TOP] + box->height + box->padding[BOTTOM];
r->x1 = r->x0 + width;
r->y1 = r->y0 + height;
}
/* Exported function documented in html/box.h */
struct box *
box_at_point(const nscss_len_ctx *len_ctx,
struct box *box,
const int x, const int y,
int *box_x, int *box_y)
{
bool skip_children;
bool physically;
assert(box);
skip_children = false;
while ((box = box_next_xy(box, box_x, box_y, skip_children))) {
if (box_contains_point(len_ctx, box, x - *box_x, y - *box_y,
&physically)) {
*box_x -= scrollbar_get_offset(box->scroll_x);
*box_y -= scrollbar_get_offset(box->scroll_y);
if (physically)
return box;
skip_children = false;
} else {
skip_children = true;
}
}
return NULL;
}
/* Exported function documented in html/box.h */
struct box *box_find_by_id(struct box *box, lwc_string *id)
{
struct box *a, *b;
bool m;
if (box->id != NULL &&
lwc_string_isequal(id, box->id, &m) == lwc_error_ok &&
m == true) {
return box;
}
for (a = box->children; a; a = a->next) {
if ((b = box_find_by_id(a, id)) != NULL) {
return b;
}
}
return NULL;
}
/* Exported function documented in html/box.h */
bool box_visible(struct box *box)
{
/* visibility: hidden */
if (box->style &&
css_computed_visibility(box->style) == CSS_VISIBILITY_HIDDEN) {
return false;
}
return true;
}
/* Exported function documented in html/box.h */
void box_dump(FILE *stream, struct box *box, unsigned int depth, bool style)
{
unsigned int i;
struct box *c, *prev;
for (i = 0; i != depth; i++) {
fprintf(stream, " ");
}
fprintf(stream, "%p ", box);
fprintf(stream, "x%i y%i w%i h%i ",
box->x, box->y, box->width, box->height);
if (box->max_width != UNKNOWN_MAX_WIDTH) {
fprintf(stream, "min%i max%i ", box->min_width, box->max_width);
}
fprintf(stream, "(%i %i %i %i) ",
box->descendant_x0, box->descendant_y0,
box->descendant_x1, box->descendant_y1);
fprintf(stream, "m(%i %i %i %i) ",
box->margin[TOP], box->margin[LEFT],
box->margin[BOTTOM], box->margin[RIGHT]);
switch (box->type) {
case BOX_BLOCK:
fprintf(stream, "BLOCK ");
break;
case BOX_INLINE_CONTAINER:
fprintf(stream, "INLINE_CONTAINER ");
break;
case BOX_INLINE:
fprintf(stream, "INLINE ");
break;
case BOX_INLINE_END:
fprintf(stream, "INLINE_END ");
break;
case BOX_INLINE_BLOCK:
fprintf(stream, "INLINE_BLOCK ");
break;
case BOX_TABLE:
fprintf(stream, "TABLE [columns %i] ", box->columns);
break;
case BOX_TABLE_ROW:
fprintf(stream, "TABLE_ROW ");
break;
case BOX_TABLE_CELL:
fprintf(stream, "TABLE_CELL [columns %i, start %i, rows %i] ",
box->columns,
box->start_column,
box->rows);
break;
case BOX_TABLE_ROW_GROUP:
fprintf(stream, "TABLE_ROW_GROUP ");
break;
case BOX_FLOAT_LEFT:
fprintf(stream, "FLOAT_LEFT ");
break;
case BOX_FLOAT_RIGHT:
fprintf(stream, "FLOAT_RIGHT ");
break;
case BOX_BR:
fprintf(stream, "BR ");
break;
case BOX_TEXT:
fprintf(stream, "TEXT ");
break;
default:
fprintf(stream, "Unknown box type ");
}
if (box->text)
fprintf(stream, "%li '%.*s' ", (unsigned long) box->byte_offset,
(int) box->length, box->text);
if (box->space)
fprintf(stream, "space ");
if (box->object) {
fprintf(stream, "(object '%s') ",
nsurl_access(hlcache_handle_get_url(box->object)));
}
if (box->iframe) {
fprintf(stream, "(iframe) ");
}
if (box->gadget)
fprintf(stream, "(gadget) ");
if (style && box->style)
nscss_dump_computed_style(stream, box->style);
if (box->href)
fprintf(stream, " -> '%s'", nsurl_access(box->href));
if (box->target)
fprintf(stream, " |%s|", box->target);
if (box->title)
fprintf(stream, " [%s]", box->title);
if (box->id)
fprintf(stream, " ID:%s", lwc_string_data(box->id));
if (box->type == BOX_INLINE || box->type == BOX_INLINE_END)
fprintf(stream, " inline_end %p", box->inline_end);
if (box->float_children)
fprintf(stream, " float_children %p", box->float_children);
if (box->next_float)
fprintf(stream, " next_float %p", box->next_float);
if (box->float_container)
fprintf(stream, " float_container %p", box->float_container);
if (box->col) {
fprintf(stream, " (columns");
for (i = 0; i != box->columns; i++) {
fprintf(stream, " (%s %s %i %i %i)",
((const char *[]) {
"UNKNOWN",
"FIXED",
"AUTO",
"PERCENT",
"RELATIVE"
})
[box->col[i].type],
((const char *[]) {
"normal",
"positioned"})
[box->col[i].positioned],
box->col[i].width,
box->col[i].min, box->col[i].max);
}
fprintf(stream, ")");
}
if (box->node != NULL) {
dom_string *name;
if (dom_node_get_node_name(box->node, &name) == DOM_NO_ERR) {
fprintf(stream, " <%s>", dom_string_data(name));
dom_string_unref(name);
}
}
fprintf(stream, "\n");
if (box->list_marker) {
for (i = 0; i != depth; i++)
fprintf(stream, " ");
fprintf(stream, "list_marker:\n");
box_dump(stream, box->list_marker, depth + 1, style);
}
for (c = box->children; c && c->next; c = c->next)
;
if (box->last != c)
fprintf(stream, "warning: box->last %p (should be %p) "
"(box %p)\n", box->last, c, box);
for (prev = 0, c = box->children; c; prev = c, c = c->next) {
if (c->parent != box)
fprintf(stream, "warning: box->parent %p (should be "
"%p) (box on next line)\n",
c->parent, box);
if (c->prev != prev)
fprintf(stream, "warning: box->prev %p (should be "
"%p) (box on next line)\n",
c->prev, prev);
box_dump(stream, c, depth + 1, style);
}
}
/* exported interface documented in html/box.h */
bool box_vscrollbar_present(const struct box * const box)
{
return box->padding[TOP] +
box->height +
box->padding[BOTTOM] +
box->border[BOTTOM].width < box->descendant_y1;
}
/* exported interface documented in html/box.h */
bool box_hscrollbar_present(const struct box * const box)
{
return box->padding[LEFT] +
box->width +
box->padding[RIGHT] +
box->border[RIGHT].width < box->descendant_x1;
}
/* Exported function documented in html/box.h */
struct box *
box_pick_text_box(struct html_content *html,
int x, int y,
int dir,
int *dx, int *dy)
{
struct box *text_box = NULL;
struct box *box;
int nr_xd, nr_yd;
int bx, by;
int fx, fy;
int tx, ty;
if (html == NULL)
return NULL;
box = html->layout;
bx = box->margin[LEFT];
by = box->margin[TOP];
fx = bx;
fy = by;
if (!box_nearest_text_box(box, bx, by, fx, fy, x, y,
dir, &text_box, &tx, &ty, &nr_xd, &nr_yd)) {
if (text_box && text_box->text && !text_box->object) {
int w = (text_box->padding[LEFT] +
text_box->width +
text_box->padding[RIGHT]);
int h = (text_box->padding[TOP] +
text_box->height +
text_box->padding[BOTTOM]);
int x1, y1;
y1 = ty + h;
x1 = tx + w;
/* ensure point lies within the text box */
if (x < tx) x = tx;
if (y < ty) y = ty;
if (y > y1) y = y1;
if (x > x1) x = x1;
}
}
/* return coordinates relative to box */
*dx = x - tx;
*dy = y - ty;
return text_box;
}