summaryrefslogtreecommitdiff
path: root/src/dom/watcher.c
blob: e22fee1365493fe4ca2579ae81c128aca9eb0841 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
/*
 * This file is part of LibNSLayout
 * Licensed under the ISC License, http://opensource.org/licenses/ISC
 * Copyright 2015 Michael Drake <tlsa@netsurf-browser.org>
 */

/** \file src/dom/watcher.c
 * DOM mutation handling
 */

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

#include "layout.h"
#include "dom/watcher.h"
#include "util/dom-str.h"
#include "util/util.h"

/**
 * Convert a dom node type to a string
 *
 * \param[in]  type		DOM node type
 * \return appropriate string.
 */
static const char *nsl__dom_node_type_to_string(dom_node_type type)
{
	const char *str[] = {
		"ELEMENT_NODE",
		"ATTRIBUTE_NODE",
		"TEXT_NODE",
		"CDATA_SECTION_NODE",
		"ENTITY_REFERENCE_NODE",
		"ENTITY_NODE",
		"PROCESSING_INSTRUCTION_NODE",
		"COMMENT_NODE",
		"DOCUMENT_NODE",
		"DOCUMENT_TYPE_NODE",
		"DOCUMENT_FRAGMENT_NODE",
		"NOTATION_NODE"
	};
	assert(DOM_NODE_TYPE_COUNT == 12);

	return str[type - 1];
}

/**
 * LibDOM event handler
 *
 * \param[in]  evt		The LibDOM event object
 * \param[in]  pw		Pointer to our nslayout_layout object
 */
static void nsl__dom_event_handler(struct dom_event *evt, void *pw)
{
	dom_event_target *node = NULL;
	dom_node_type node_type;
	dom_string *name = NULL;
	dom_string *type = NULL;
	dom_exception exc;

	UNUSED(pw);

	printf("  DOM Event: ");

	/* Ugly test to see what events come out */
	exc = dom_event_get_target(evt, &node);
	if ((exc != DOM_NO_ERR) || (node == NULL)) {
		printf("FAILED to get target node!\n");
		goto fail;
	}

	exc = dom_node_get_node_type(node, &node_type);
	if (exc != DOM_NO_ERR) {
		printf("FAILED to get target node type!\n");
		goto fail;
	}

	if (node_type == DOM_ELEMENT_NODE) {
		exc = dom_node_get_node_name(node, &name);
		if ((exc != DOM_NO_ERR) || (name == NULL)) {
			printf("FAILED to get target node name!\n");
			goto fail;
		}
	}

	exc = dom_event_get_type(evt, &type);
	if ((exc != DOM_NO_ERR) || (type == NULL)) {
		printf("FAILED to get event type!\n");
		goto fail;
	}

	if (node_type == DOM_ELEMENT_NODE) {
		printf("<%s> %s",
				dom_string_data(name),
				dom_string_data(type));
	} else {
		printf("%s %s",
				nsl__dom_node_type_to_string(node_type),
				dom_string_data(type));
	}

	/* TODO: Based on event type:
	 *         1. call to do (re)selection:
	 *              a. all nodes?
	 *              b. just this node?
	 *         2. call to update layout, if needed.
	 */

fail:
	if (type != NULL) dom_string_unref(type);
	if (name != NULL) dom_string_unref(name);
	if (node != NULL) dom_node_unref(node);

	printf("\n");
}

/* Exported function, documented in src/dom/event.h */
nslayout_error nsl_dom_watcher_add_for_layout(nslayout_layout *layout)
{
	nslayout_error err;
	dom_exception exc;

	/* TODO: LibDOM event listeners are really slow.  Need to find a better
	 *       way to get DOM change notifications.
	 */

	exc = dom_event_listener_create(layout->doc, nsl__dom_event_handler,
			layout, &layout->listener);
	if (exc != DOM_NO_ERR) {
		return NSL_DOM_ERR(exc);
	}
	exc = dom_event_target_add_event_listener(
			layout->doc, nsl_dom_str_node_inserted, 
			layout->listener, false);
	if (exc != DOM_NO_ERR) {
		err = NSL_DOM_ERR(exc);
		goto fail;
	}
	exc = dom_event_target_add_event_listener(
			layout->doc, nsl_dom_str_subtree_modified, 
			layout->listener, false);
	if (exc != DOM_NO_ERR) {
		(void) dom_event_target_remove_event_listener(
				layout->doc, nsl_dom_str_node_inserted,
				layout->listener, false);
		err = NSL_DOM_ERR(exc);
		goto fail;
	}

	return NSLAYOUT_OK;

fail:
	dom_event_listener_unref(layout->listener);
	layout->listener = NULL;

	return err;
}

/* Exported function, documented in src/dom/event.h */
nslayout_error nsl_dom_watcher_remove_for_layout(nslayout_layout *layout)
{
	dom_exception exc1, exc2;

	exc1 = dom_event_target_remove_event_listener(
			layout->doc, nsl_dom_str_node_inserted, 
			layout->listener, false);
	exc2 = dom_event_target_remove_event_listener(
			layout->doc, nsl_dom_str_subtree_modified, 
			layout->listener, false);

	if (exc1 != DOM_NO_ERR) {
		return NSL_DOM_ERR(exc1);
	}
	if (exc2 != DOM_NO_ERR) {
		return NSL_DOM_ERR(exc2);
	}

	dom_event_listener_unref(layout->listener);
	layout->listener = NULL;

	return NSLAYOUT_OK;
}