# HG changeset patch
# User David Demelier <markand@malikania.fr>
# Date 1602692458 -7200
# Node ID 7d7ea7a9cf50e4f65272dbc51f32cba261d6cefa
# Parent  7f1af54bb35a912eecac940384a3b15c3cfd4131
core: add theme_shallow function

diff -r 7f1af54bb35a -r 7d7ea7a9cf50 libcore/core/message.c
--- a/libcore/core/message.c	Wed Oct 14 18:11:38 2020 +0200
+++ b/libcore/core/message.c	Wed Oct 14 18:20:58 2020 +0200
@@ -80,14 +80,13 @@
 draw_lines(const struct message *msg)
 {
 	struct theme theme;
-	struct font *font;
 	unsigned int lineh;
 
 	/* Shallow copy theme to modify colors. */
-	memcpy(&theme, THEME(msg), sizeof (theme));
+	theme_shallow(&theme, msg->theme);
 
-	font = theme.fonts[THEME_FONT_INTERFACE];
-	lineh = font_height(font);
+	/* Compute text size for list alignment. */
+	lineh = font_height(theme.fonts[THEME_FONT_INTERFACE]);
 
 	for (int i = 0; i < 6; ++i) {
 		if (!msg->text[i])
diff -r 7f1af54bb35a -r 7d7ea7a9cf50 libcore/core/theme.c
--- a/libcore/core/theme.c	Wed Oct 14 18:11:38 2020 +0200
+++ b/libcore/core/theme.c	Wed Oct 14 18:20:58 2020 +0200
@@ -18,6 +18,7 @@
 
 #include <assert.h>
 #include <stddef.h>
+#include <string.h>
 
 #include "button.h"
 #include "checkbox.h"
@@ -258,6 +259,14 @@
 }
 
 void
+theme_shallow(struct theme *dst, const struct theme *src)
+{
+	assert(dst);
+
+	memcpy(dst, src ? src : &default_theme, sizeof (*src));
+}
+
+void
 theme_draw_frame(struct theme *t, const struct frame *frame)
 {
 	assert(frame);
diff -r 7f1af54bb35a -r 7d7ea7a9cf50 libcore/core/theme.h
--- a/libcore/core/theme.h	Wed Oct 14 18:11:38 2020 +0200
+++ b/libcore/core/theme.h	Wed Oct 14 18:20:58 2020 +0200
@@ -121,6 +121,23 @@
 theme_default(void);
 
 /**
+ * Convenient shortcut to shallow copy src into dst.
+ *
+ * Use this function when you want your own local copy of a theme because you
+ * want to modify some attributes.
+ *
+ * This is a shortcut to `memcpy(dst, src, sizeof (*src))`.
+ *
+ * \pre dst != NULL
+ * \param dst the destination theme
+ * \param src the source theme (may be NULL)
+ * \note Resources are not cloned, internal pointers will adress the same
+ *       regions.
+ */
+void
+theme_shallow(struct theme *dst, const struct theme *src);
+
+/**
  * Get the desired padding between GUI elements.
  *
  * \param t the theme to use (may be NULL)