Put the font operations table alongside all the other core API

The netsurf core is driven from numerous operation tables most of
which are now set through a common netsurf_register() interface. The
font and plotting interfaces are currently separate and unlike all the
other operation tables are modified for differing contexts.

This change moves the font operations alongside all the other
operations table and remove unnecessary interaction with the renderers
font internals. Further this also removes the need for css internals
to be visible in frontends.

1 files changed, 97 insertions, 0 deletions

diff --git a/desktop/font.h b/desktop/font.h
new file mode 100644
index 000000000..4ebd75d73
--- /dev/null
+++ b/desktop/font.h
@@ -0,0 +1,97 @@
+/*
+ * Copyright 2003 Phil Mellor <monkeyson@users.sourceforge.net>
+ * Copyright 2005 James Bursa <bursa@users.sourceforge.net>
+ * Copyright 2004 John Tytgat <joty@netsurf-browser.org>
+ *
+ * This file is part of NetSurf, http://www.netsurf-browser.org/
+ *
+ * NetSurf is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * NetSurf is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** \file
+ * Font handling interface.
+ *
+ * These functions provide font related services. They all work on
+ * UTF-8 strings with lengths given.
+ *
+ * Note that an interface to painting is not defined here. Painting is
+ * redirected through platform-dependent plotters anyway, so there is
+ * no gain in abstracting it here.
+ */
+
+#ifndef _NETSURF_DESKTOP_FONT_H_
+#define _NETSURF_DESKTOP_FONT_H_
+
+#include <stdbool.h>
+#include <stddef.h>
+
+#include "desktop/plot_style.h"
+
+struct font_functions
+{
+	/**
+	 * Measure the width of a string.
+	 *
+	 * \param  fstyle  plot style for this text
+	 * \param  string  UTF-8 string to measure
+	 * \param  length  length of string, in bytes
+	 * \param  width   updated to width of string[0..length)
+	 * \return  true on success, false on error and error reported
+	 */
+	bool (*font_width)(const plot_font_style_t *fstyle,
+			const char *string, size_t length,
+			int *width);
+	/**
+	 * Find the position in a string where an x coordinate falls.
+	 *
+	 * \param  fstyle       style for this text
+	 * \param  string       UTF-8 string to measure
+	 * \param  length       length of string, in bytes
+	 * \param  x            x coordinate to search for
+	 * \param  char_offset  updated to offset in string of actual_x, [0..length]
+	 * \param  actual_x     updated to x coordinate of character closest to x
+	 * \return  true on success, false on error and error reported
+	 */
+	bool (*font_position_in_string)(const plot_font_style_t *fstyle,
+			const char *string, size_t length,
+			int x, size_t *char_offset, int *actual_x);
+	/**
+	 * Find where to split a string to make it fit a width.
+	 *
+	 * \param  fstyle       style for this text
+	 * \param  string       UTF-8 string to measure
+	 * \param  length       length of string, in bytes
+	 * \param  x            width available
+	 * \param  char_offset  updated to offset in string of actual_x, [1..length]
+	 * \param  actual_x     updated to x coordinate of character closest to x
+	 * \return  true on success, false on error and error reported
+	 *
+	 * On exit, char_offset indicates first character after split point.
+	 *
+	 * Note: char_offset of 0 should never be returned.
+	 *
+	 *   Returns:
+	 *     char_offset giving split point closest to x, where actual_x <= x
+	 *   else
+	 *     char_offset giving split point closest to x, where actual_x > x
+	 *
+	 * Returning char_offset == length means no split possible
+	 */
+	bool (*font_split)(const plot_font_style_t *fstyle,
+			const char *string, size_t length,
+			int x, size_t *char_offset, int *actual_x);
+};
+
+extern const struct font_functions nsfont;
+
+#endif