Media Queries: datastructures and plumbing.

No parse implementation as yet.

Selection hasn't been updated, either. One item of note
in that area is that a client currently provides the
media for top-level sheets being added to a selection
context. This probably needs to change to providing a
lwc_string containing the verbatim media query from
the containing document's import mechanism. That way,
the internal representation of media queries can remain
opaque to clients.

1 files changed, 100 insertions, 0 deletions

diff --git a/src/parse/mq.h b/src/parse/mq.h
new file mode 100644
index 0000000..eeb55da
--- /dev/null
+++ b/src/parse/mq.h
@@ -0,0 +1,100 @@
+/*
+ * This file is part of LibCSS.
+ * Licensed under the MIT License,
+ *		  http://www.opensource.org/licenses/mit-license.php
+ * Copyright 2016 John-Mark Bell <jmb@netsurf-browser.org>
+ */
+
+#ifndef css_parse_mq_h_
+#define css_parse_mq_h_
+
+#include <parserutils/utils/vector.h>
+#include "parse/language.h"
+
+typedef struct {
+	enum {
+		CSS_MQ_VALUE_TYPE_NUM,
+		CSS_MQ_VALUE_TYPE_DIM,
+		CSS_MQ_VALUE_TYPE_IDENT,
+		CSS_MQ_VALUE_TYPE_RATIO
+	} type;
+	union {
+		css_fixed num_or_ratio; /* Where ratio is the result of a/b */
+		struct {
+			css_fixed len;
+			css_unit unit;
+		} dim;
+		lwc_string *ident;
+	} data;
+} css_mq_value;
+
+/*
+ * "name : value" is encoded as "name = value"
+ * "name" is encoded by setting the operator to "bool"
+ * "name op value" is encoded verbatim (with op2 set to "unused")
+ * "value op name" inverts the operator to encode (i.e < becomes >=) (and sets op2 to "unused")
+ * "value op name op value" is encoded using op2 and value2
+ */
+typedef enum {
+	CSS_MQ_FEATURE_OP_BOOL, /* op only */
+	CSS_MQ_FEATURE_OP_UNUSED = CSS_MQ_FEATURE_OP_BOOL, /* op2 only */
+
+	CSS_MQ_FEATURE_OP_LT,
+	CSS_MQ_FEATURE_OP_LTE,
+	CSS_MQ_FEATURE_OP_EQ, /* op only */
+	CSS_MQ_FEATURE_OP_GTE,
+	CSS_MQ_FEATURE_OP_GT
+} css_mq_feature_op;
+
+typedef struct {
+	lwc_string *name;
+	css_mq_feature_op op;
+	css_mq_feature_op op2;
+	css_mq_value value;
+	css_mq_value value2;
+} css_mq_feature;
+
+typedef struct css_mq_cond_or_feature css_mq_cond_or_feature;
+
+typedef struct {
+	uint32_t nparts;
+	css_mq_cond_or_feature **parts;
+} css_mq_cond_parts;
+
+typedef struct {
+	uint32_t negate : 1, /* set if "not" */
+		 op     : 1; /* clear if "and", set if "or" */
+	css_mq_cond_parts *parts;
+} css_mq_cond;
+
+struct css_mq_cond_or_feature {
+	enum {
+		CSS_MQ_FEATURE,
+		CSS_MQ_COND
+	} type;
+	union {
+		css_mq_cond cond;
+		css_mq_feature feat;
+	} data;
+};
+
+typedef struct css_mq_query {
+	struct css_mq_query *next;
+
+	uint32_t negate_type : 1, /* set if "not type" */
+		 cond_op     : 1; /* clear if "and", set if "or" */
+	lwc_string *type; /* or NULL */
+
+	uint32_t nconds;
+	css_mq_cond **conds;
+} css_mq_query;
+
+css_error css__mq_parse_media_list(css_language *c,
+		const parserutils_vector *vector, int *ctx,
+		css_mq_query **media);
+
+/** \todo is this necessary? */
+css_mq_query *css__mq_query_ref(css_mq_query *media);
+css_mq_query *css__mq_query_unref(css_mq_query *media);
+
+#endif