From 5776d3448c50d58af0eac8f3960200aa1b5fc1a0 Mon Sep 17 00:00:00 2001
From: Michael Drake <tlsa@netsurf-browser.org>
Date: Wed, 3 Jan 2018 16:59:58 +0000
Subject: CSS computed style composition: Update for new CSS units.

Since the nscss_compute_font_size callback now needs to convert
new units to absolute values, and some of these units require info
from the root element's style, there are knock-on changes to ensure
that the required info is available where its needed.
---
 content/handlers/css/select.c | 52 ++++++++++++++++++++++++++++++++++++++-----
 content/handlers/css/select.h |  1 +
 2 files changed, 48 insertions(+), 5 deletions(-)

(limited to 'content/handlers/css')

diff --git a/content/handlers/css/select.c b/content/handlers/css/select.c
index 328d6a711..ee79eb394 100644
--- a/content/handlers/css/select.c
+++ b/content/handlers/css/select.c
@@ -278,7 +278,7 @@ css_select_results *nscss_get_style(nscss_select_ctx *ctx, dom_node *n,
 		 * element's style */
 		error = css_computed_style_compose(ctx->parent_style,
 				styles->styles[CSS_PSEUDO_ELEMENT_NONE],
-				nscss_compute_font_size, NULL,
+				nscss_compute_font_size, ctx,
 				&composed);
 		if (error != CSS_OK) {
 			css_select_results_destroy(styles);
@@ -310,7 +310,7 @@ css_select_results *nscss_get_style(nscss_select_ctx *ctx, dom_node *n,
 		error = css_computed_style_compose(
 				styles->styles[CSS_PSEUDO_ELEMENT_NONE],
 				styles->styles[pseudo_element],
-				nscss_compute_font_size, NULL,
+				nscss_compute_font_size, ctx,
 				&composed);
 		if (error != CSS_OK) {
 			/* TODO: perhaps this shouldn't be quite so
@@ -349,7 +349,7 @@ css_computed_style *nscss_get_blank_style(nscss_select_ctx *ctx,
 	/* TODO: Do we really need to compose?  Initial style shouldn't
 	 * have any inherited properties. */
 	error = css_computed_style_compose(parent, partial,
-			nscss_compute_font_size, NULL, &composed);
+			nscss_compute_font_size, ctx, &composed);
 	css_computed_style_destroy(partial);
 	if (error != CSS_OK) {
 		css_computed_style_destroy(composed);
@@ -422,14 +422,37 @@ css_error nscss_compute_font_size(void *pw, const css_hint *parent,
 				FDIV(parent_size.value, FLTTOFIX(1.2));
 		size->data.length.unit = parent_size.unit;
 	} else if (size->data.length.unit == CSS_UNIT_EM ||
-			size->data.length.unit == CSS_UNIT_EX) {
+			size->data.length.unit == CSS_UNIT_EX ||
+			size->data.length.unit == CSS_UNIT_CAP ||
+			size->data.length.unit == CSS_UNIT_CH ||
+			size->data.length.unit == CSS_UNIT_IC) {
 		size->data.length.value =
 			FMUL(size->data.length.value, parent_size.value);
 
-		if (size->data.length.unit == CSS_UNIT_EX) {
+		switch (size->data.length.unit) {
+		case CSS_UNIT_EX:
 			/* 1ex = 0.6em in NetSurf */
 			size->data.length.value = FMUL(size->data.length.value,
 					FLTTOFIX(0.6));
+			break;
+		case CSS_UNIT_CAP:
+			/* Height of captals.  1cap = 0.9em in NetSurf. */
+			size->data.length.value = FMUL(size->data.length.value,
+					FLTTOFIX(0.9));
+			break;
+		case CSS_UNIT_CH:
+			/* Width of '0'.  1ch = 0.4em in NetSurf. */
+			size->data.length.value = FMUL(size->data.length.value,
+					FLTTOFIX(0.4));
+			break;
+		case CSS_UNIT_IC:
+			/* Width of U+6C43.  1ic = 1.1em in NetSurf. */
+			size->data.length.value = FMUL(size->data.length.value,
+					FLTTOFIX(1.1));
+			break;
+		default:
+			/* No scaling required for EM. */
+			break;
 		}
 
 		size->data.length.unit = parent_size.unit;
@@ -437,6 +460,25 @@ css_error nscss_compute_font_size(void *pw, const css_hint *parent,
 		size->data.length.value = FDIV(FMUL(size->data.length.value,
 				parent_size.value), INTTOFIX(100));
 		size->data.length.unit = parent_size.unit;
+	} else if (size->data.length.unit == CSS_UNIT_REM) {
+		nscss_select_ctx *ctx = pw;
+		if (parent == NULL) {
+			size->data.length.value = parent_size.value;
+			size->data.length.unit = parent_size.unit;
+		} else {
+			css_computed_font_size(ctx->root_style,
+					&parent_size.value,
+					&size->data.length.unit);
+			size->data.length.value = FMUL(
+					size->data.length.value,
+					parent_size.value);
+		}
+	} else if (size->data.length.unit == CSS_UNIT_RLH) {
+		/** TODO: Convert root element line-height to absolute value. */
+		size->data.length.value = FMUL(size->data.length.value, FDIV(
+				INTTOFIX(nsoption_int(font_size)),
+				INTTOFIX(10)));
+		size->data.length.unit = CSS_UNIT_PT;
 	}
 
 	size->status = CSS_FONT_SIZE_DIMENSION;
diff --git a/content/handlers/css/select.h b/content/handlers/css/select.h
index abfb85814..9fa6d3a56 100644
--- a/content/handlers/css/select.h
+++ b/content/handlers/css/select.h
@@ -37,6 +37,7 @@ typedef struct nscss_select_ctx
 	bool quirks;
 	struct nsurl *base_url;
 	lwc_string *universal;
+	const css_computed_style *root_style;
 	const css_computed_style *parent_style;
 } nscss_select_ctx;
 
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