link.c

一个很有名的浏览器

/* Links viewing/manipulation handling */
/* $Id: link.c,v 1.309.2.6 2005/05/01 21:00:42 jonas Exp $ */

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

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

#include "elinks.h"

#include "bfu/listmenu.h"
#include "bfu/menu.h"
#include "dialogs/menu.h"
#include "dialogs/status.h"
#include "document/document.h"
#include "document/forms.h"
#include "document/html/parser.h"
#include "document/html/renderer.h"
#include "document/options.h"
#include "document/view.h"
#include "ecmascript/ecmascript.h"
#include "intl/gettext/libintl.h"
#include "protocol/uri.h"
#include "sched/session.h"
#include "sched/task.h"
#include "terminal/color.h"
#include "terminal/draw.h"
#include "terminal/kbd.h"
#include "terminal/screen.h"
#include "terminal/tab.h"
#include "terminal/terminal.h"
#include "util/conv.h"
#include "util/error.h"
#include "util/memory.h"
#include "util/object.h"
#include "util/string.h"
#include "viewer/text/form.h"
#include "viewer/text/link.h"
#include "viewer/text/search.h"
#include "viewer/text/textarea.h"
#include "viewer/text/view.h"
#include "viewer/text/vs.h"


/* Perhaps some of these would be more fun to have in viewer/common/, dunno.
 * --pasky */


static int
current_link_evhook(struct document_view *doc_view, enum script_event_hook_type type)
{
#ifdef CONFIG_ECMASCRIPT
	struct link *link;
	struct script_event_hook *evhook;

	assert(doc_view && doc_view->vs);
	link = get_current_link(doc_view);
	if (!link) return -1;
	if (!link->event_hooks) return -1;

	if (!doc_view->vs->ecmascript) return -1;

	foreach (evhook, *link->event_hooks) {
		struct string src = INIT_STRING(evhook->src, strlen(evhook->src));

		if (evhook->type != type) continue;
		/* TODO: Some even handlers return a bool. */
		if (!ecmascript_eval_boolback(doc_view->vs->ecmascript, &src))
			return 0;
	}

	return 1;
#else
	return -1;
#endif
}

#define current_link_hover(dv) \
do { \
	current_link_evhook(dv, SEVHOOK_ONMOUSEOVER); \
	current_link_evhook(dv, SEVHOOK_ONHOVER); \
	current_link_evhook(dv, SEVHOOK_ONFOCUS); \
} while (0)
#define current_link_blur(dv) \
do { \
	current_link_evhook(dv, SEVHOOK_ONMOUSEOUT); \
	current_link_evhook(dv, SEVHOOK_ONBLUR); \
} while (0)


void
set_link(struct document_view *doc_view)
{
	assert(doc_view);
	if_assert_failed return;

	if (current_link_is_visible(doc_view)) return;

	find_link_page_down(doc_view);
}

static inline int
get_link_cursor_offset(struct document_view *doc_view, struct link *link)
{
	struct form_control *fc;
	struct form_state *fs;

	switch (link->type) {
		case LINK_CHECKBOX:
			return 1;

		case LINK_BUTTON:
			return 2;

		case LINK_FIELD:
			fc = get_link_form_control(link);
			fs = find_form_state(doc_view, fc);
			return fs ? fs->state - fs->vpos : 0;

		case LINK_AREA:
			fc = get_link_form_control(link);
			fs = find_form_state(doc_view, fc);
			return fs ? area_cursor(fc, fs) : 0;

		case LINK_HYPERTEXT:
		case LINK_MAP:
		case LINK_SELECT:
			return 0;
	}

	return 0;
}

/* Allocate doc_view->link_bg with enough space to save the colour
 * and attributes of each point of the given link plus one byte
 * for the template character. Initialise that template character
 * with the colour and attributes appropriate for an active link. */
static inline struct screen_char *
init_link_drawing(struct document_view *doc_view, struct link *link, int invert)
{
	struct document_options *doc_opts;
	struct screen_char *template;
	enum color_flags color_flags;
	enum color_mode color_mode;
	struct color_pair colors;

	/* Allocate an extra background char to work on here. */
	doc_view->link_bg = mem_alloc((1 + link->npoints) * sizeof(*doc_view->link_bg));
	if (!doc_view->link_bg) return NULL;

	doc_view->link_bg_n = link->npoints;

	/* Setup the template char. */
	template = &doc_view->link_bg[link->npoints].c;

	template->attr = SCREEN_ATTR_STANDOUT;

	/* For the color mode options we use the options set for the document.
	 * But for the active link options we prefer to use the global
	 * global_doc_opts since it is kept up to date by an option change
	 * hook. However if it is not available fall back to use the options
	 * from the viewed document. */
	doc_opts = &doc_view->document->options;

	color_flags = (doc_opts->color_flags | COLOR_DECREASE_LIGHTNESS);
	color_mode = doc_opts->color_mode;

	if (global_doc_opts) doc_opts = global_doc_opts;

	if (doc_opts->underline_active_link)
		template->attr |= SCREEN_ATTR_UNDERLINE;

	if (doc_opts->bold_active_link)
		template->attr |= SCREEN_ATTR_BOLD;

	if (doc_opts->color_active_link) {
		colors.foreground = doc_opts->active_link_fg;
		colors.background = doc_opts->active_link_bg;
	} else {
		colors.foreground = link->color.foreground;
		colors.background = link->color.background;
	}

	if (doc_opts->invert_active_link && invert) {
		swap_values(color_t, colors.foreground, colors.background);

		/* Highlight text-input form-fields correctly if contrast
		 * correction is needed. */
		if (link_is_textinput(link)) {
			/* Make sure to use the options belonging to the
			 * current document when checking for fg and bg color
			 * usage. */
			doc_opts = &doc_view->document->options;

			/* Are we fallen angels who didn't want to believe that
			 * nothing /is/ nothing and so were born to lose our
			 * loved ones and dear friends one by one and finally
			 * our own life, to see it proved? --Kerouac */

			/* Wipe out all default correction for 16 color mode */
			color_flags = (color_flags & ~COLOR_INCREASE_CONTRAST);
			/* Make contrast correction invert things properly */
			color_flags |= COLOR_ENSURE_INVERTED_CONTRAST;
		}
	}

	set_term_color(template, &colors, color_flags, color_mode);

	return template;
}

/* Save the current link's colours and attributes to doc_view->link_bg
 * and give it the appropriate colour and attributes for an active link. */
void
draw_current_link(struct session *ses, struct document_view *doc_view)
{
	struct terminal *term = ses->tab->term;
	struct screen_char *template;
	struct link *link;
	int cursor_offset;
	int xpos, ypos;
	int i;

	assert(term && doc_view && doc_view->vs);
	if_assert_failed return;

	assert(ses->tab == get_current_tab(term));
	if_assert_failed return;

	assertm(!doc_view->link_bg, "link background not empty");
	if_assert_failed mem_free(doc_view->link_bg);

	link = get_current_link(doc_view);
	if (!link) return;

	i = !link_is_textinput(link) || ses->insert_mode == INSERT_MODE_OFF;
	template = init_link_drawing(doc_view, link, i);
	if (!template) return;

	xpos = doc_view->box.x - doc_view->vs->x;
	ypos = doc_view->box.y - doc_view->vs->y;

	if (ses->insert_mode == INSERT_MODE_OFF
	    && ses->navigate_mode == NAVIGATE_CURSOR_ROUTING) {
		/* If we are navigating using cursor routing and not editing a
		 * text-input form-field never set the cursor. */
		cursor_offset = -1;
	} else {
		cursor_offset = get_link_cursor_offset(doc_view, link);
	}

	for (i = 0; i < link->npoints; i++) {
		int x = link->points[i].x + xpos;
		int y = link->points[i].y + ypos;
		struct screen_char *co;

		if (!is_in_box(&doc_view->box, x, y)) {
			doc_view->link_bg[i].x = -1;
			doc_view->link_bg[i].y = -1;
			continue;
		}

		doc_view->link_bg[i].x = x;
		doc_view->link_bg[i].y = y;

		co = get_char(term, x, y);
		copy_screen_chars(&doc_view->link_bg[i].c, co, 1);

		if (i == cursor_offset) {
			int blockable = (!link_is_textinput(link)
					 && co->color != template->color);

			set_cursor(term, x, y, blockable);
			set_window_ptr(ses->tab, x, y);
		}

 		template->data = co->data;
 		copy_screen_chars(co, template, 1);
		set_screen_dirty(term->screen, y, y);
	}
}

void
free_link(struct document_view *doc_view)
{
	assert(doc_view);
	if_assert_failed return;

	mem_free_set(&doc_view->link_bg, NULL);
	doc_view->link_bg_n = 0;
}

/* Restore the colours and attributes that the active link had
 * before it was selected. */
void
clear_link(struct terminal *term, struct document_view *doc_view)
{
	assert(term && doc_view);
	if_assert_failed return;

	if (doc_view->link_bg) {
		struct link_bg *link_bg = doc_view->link_bg;
		int i;

		for (i = doc_view->link_bg_n - 1; i >= 0; i--) {
			struct link_bg *bgchar = &link_bg[i];

			if (bgchar->x != -1 && bgchar->y != -1) {
				struct terminal_screen *screen = term->screen;
				struct screen_char *co;

				co = get_char(term, bgchar->x, bgchar->y);
				copy_screen_chars(co, &bgchar->c, 1);
				set_screen_dirty(screen, bgchar->y, bgchar->y);
			}
		}

		free_link(doc_view);
	}
}

struct link *
get_first_link(struct document_view *doc_view)
{
	struct link *link, *undef;
	struct document *document;
	int height;
	int i;

	assert(doc_view && doc_view->document);
	if_assert_failed return NULL;

	document = doc_view->document;

	if (!document->lines1) return NULL;

	height = doc_view->vs->y + doc_view->box.height;
	link = undef = document->links + document->nlinks;

	for (i = int_max(0, doc_view->vs->y);
	     i < int_min(height, document->height);
	     i++) {
		if (document->lines1[i]
		    && document->lines1[i] < link)
			link = document->lines1[i];
	}

	return (link == undef) ? NULL : link;
}

struct link *
get_last_link(struct document_view *doc_view)
{
	struct link *link = NULL;
	struct document *document;
	int height;
	int i;

	assert(doc_view && doc_view->document);
	if_assert_failed return NULL;

	document = doc_view->document;

	if (!document->lines2) return NULL;

	height = doc_view->vs->y + doc_view->box.height;

	for (i = int_max(0, doc_view->vs->y);
	     i < int_min(height, document->height);
	     i++)
		if (document->lines2[i] > link)
			link = document->lines2[i];

	return link;
}

static inline int
link_in_view_x(struct document_view *doc_view, struct link *link)
{
	int i, dx, width;

	assert(doc_view && link);
	if_assert_failed return 0;

	dx = doc_view->vs->x;
	width = doc_view->box.width;

	for (i = 0; i < link->npoints; i++) {
		int x = link->points[i].x - dx;

		if (x >= 0 && x < width)
			return 1;
	}

	return 0;
}

int
link_in_view_y(struct document_view *doc_view, struct link *link)
{
	int i, dy, height;

	assert(doc_view && link);
	if_assert_failed return 0;

	dy = doc_view->vs->y;
	height = doc_view->box.height;

	for (i = 0; i < link->npoints; i++) {
		int y = link->points[i].y - dy;

		if (y >= 0 && y < height)
			return 1;
	}

	return 0;
}

int
link_in_view(struct document_view *doc_view, struct link *link)
{
	assert(doc_view && link);
	if_assert_failed return 0;
	return link_in_view_y(doc_view, link) && link_in_view_x(doc_view, link);
}

int
current_link_is_visible(struct document_view *doc_view)
{
	struct link *link;