Add support for SVG stroke-opacity property

  https://www.w3.org/TR/SVGTiny12/painting.html#StrokeOpacityProperty

This property is unique to SVG documents, but is otherwise analogous
to the usual CSS "opacity" property (and the recently-added SVG
fill-opacity property).

3 files changed, 75 insertions, 0 deletions

diff --git a/src/select/properties/Makefile b/src/select/properties/Makefile
index 2e10f4a..eee6cc3 100644
--- a/src/select/properties/Makefile
+++ b/src/select/properties/Makefile
@@ -108,6 +108,7 @@ speak_header.c \
 speak_numeral.c \
 speak_punctuation.c \
 stress.c \
+stroke_opacity.c \
 table_layout.c \
 text_align.c \
 text_decoration.c \
diff --git a/src/select/properties/properties.h b/src/select/properties/properties.h
index fba5be8..cb0b213 100644
--- a/src/select/properties/properties.h
+++ b/src/select/properties/properties.h
@@ -130,6 +130,7 @@ PROPERTY_FUNCS(speak_punctuation);
 PROPERTY_FUNCS(speak);
 PROPERTY_FUNCS(speech_rate);
 PROPERTY_FUNCS(stress);
+PROPERTY_FUNCS(stroke_opacity);
 PROPERTY_FUNCS(table_layout);
 PROPERTY_FUNCS(text_align);
 PROPERTY_FUNCS(text_decoration);
diff --git a/src/select/properties/stroke_opacity.c b/src/select/properties/stroke_opacity.c
new file mode 100644
index 0000000..c27e127
--- /dev/null
+++ b/src/select/properties/stroke_opacity.c
@@ -0,0 +1,73 @@
+/*
+ * This file is part of LibCSS
+ * Licensed under the MIT License,
+ *		  http://www.opensource.org/licenses/mit-license.php
+ */
+
+#include "bytecode/bytecode.h"
+#include "bytecode/opcodes.h"
+#include "select/propset.h"
+#include "select/propget.h"
+#include "utils/utils.h"
+
+#include "select/properties/properties.h"
+#include "select/properties/helpers.h"
+
+css_error css__cascade_stroke_opacity(uint32_t opv, css_style *style,
+		css_select_state *state)
+{
+	uint16_t value = CSS_STROKE_OPACITY_INHERIT;
+	css_fixed stroke_opacity = 0;
+
+	if (hasFlagValue(opv) == false) {
+		value = CSS_STROKE_OPACITY_SET;
+
+		stroke_opacity = *((css_fixed *) style->bytecode);
+		advance_bytecode(style, sizeof(stroke_opacity));
+	}
+
+	if (css__outranks_existing(getOpcode(opv), isImportant(opv), state,
+			getFlagValue(opv))) {
+		return set_stroke_opacity(state->computed, value, stroke_opacity);
+	}
+
+	return CSS_OK;
+}
+
+css_error css__set_stroke_opacity_from_hint(const css_hint *hint,
+		css_computed_style *style)
+{
+	return set_stroke_opacity(style, hint->status, hint->data.fixed);
+}
+
+css_error css__initial_stroke_opacity(css_select_state *state)
+{
+	return set_stroke_opacity(state->computed, CSS_STROKE_OPACITY_SET, INTTOFIX(1));
+}
+
+css_error css__copy_stroke_opacity(
+		const css_computed_style *from,
+		css_computed_style *to)
+{
+	css_fixed stroke_opacity = 0;
+	uint8_t type = get_stroke_opacity(from, &stroke_opacity);
+
+	if (from == to) {
+		return CSS_OK;
+	}
+
+	return set_stroke_opacity(to, type, stroke_opacity);
+}
+
+css_error css__compose_stroke_opacity(const css_computed_style *parent,
+		const css_computed_style *child,
+		css_computed_style *result)
+{
+	css_fixed stroke_opacity = 0;
+	uint8_t type = get_stroke_opacity(child, &stroke_opacity);
+
+	return css__copy_stroke_opacity(
+			type == CSS_STROKE_OPACITY_INHERIT ? parent : child,
+			result);
+}
+