Initial revision

1 files changed, 774 insertions, 0 deletions

diff --git a/lib/widgets/ephy-ellipsizing-label.c b/lib/widgets/ephy-ellipsizing-label.c
new file mode 100644
index 000000000..13f911078
--- /dev/null
+++ b/lib/widgets/ephy-ellipsizing-label.c
@@ -0,0 +1,774 @@
+/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 8; tab-width: 8 -*- */
+
+/* eel-ellipsizing-label.c: Subclass of GtkLabel that ellipsizes the text.
+
+   Copyright (C) 2001 Eazel, Inc.
+
+   The Gnome Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The Gnome Library 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
+   Library General Public License for more priv.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the Gnome Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.
+
+   Author: John Sullivan <sullivan@eazel.com>,
+	   Marco Pesenti Gritti <marco@it.gnome.org> Markup support
+ */
+
+#include "ephy-ellipsizing-label.h"
+
+#include <string.h>
+
+struct EphyEllipsizingLabelPrivate
+{
+	char *full_text;
+
+	EphyEllipsizeMode mode;
+};
+
+static void ephy_ellipsizing_label_class_init (EphyEllipsizingLabelClass *class);
+static void ephy_ellipsizing_label_init       (EphyEllipsizingLabel      *label);
+
+static GObjectClass *parent_class = NULL;
+
+static int
+ephy_strcmp (const char *string_a, const char *string_b)
+{
+       return strcmp (string_a == NULL ? "" : string_a,
+                      string_b == NULL ? "" : string_b);
+}
+
+static gboolean
+ephy_str_is_equal (const char *string_a, const char *string_b)
+{
+       return ephy_strcmp (string_a, string_b) == 0;
+}
+
+#define ELLIPSIS "..."
+
+/* Caution: this is an _expensive_ function */
+static int
+measure_string_width (const char  *string,
+		      PangoLayout *layout,
+		      gboolean markup)
+{
+	int width;
+
+	if (markup)
+	{
+		pango_layout_set_markup (layout, string, -1);
+	}
+	else
+	{
+		pango_layout_set_text (layout, string, -1);
+	}
+
+	pango_layout_get_pixel_size (layout, &width, NULL);
+
+	return width;
+}
+
+/* this is also plenty slow */
+static void
+compute_character_widths (const char    *string,
+			  PangoLayout   *layout,
+			  int           *char_len_return,
+			  int          **widths_return,
+			  int          **cuts_return,
+			  gboolean       markup)
+{
+	int *widths;
+	int *offsets;
+	int *cuts;
+	int char_len;
+	int byte_len;
+	const char *p;
+	const char *nm_string;
+	int i;
+	PangoLayoutIter *iter;
+	PangoLogAttr *attrs;
+
+#define BEGINS_UTF8_CHAR(x) (((x) & 0xc0) != 0x80)
+
+	if (markup)
+	{
+		pango_layout_set_markup (layout, string, -1);
+	}
+	else
+	{
+		pango_layout_set_text (layout, string, -1);
+	}
+
+	nm_string = pango_layout_get_text (layout);
+
+	char_len = g_utf8_strlen (nm_string, -1);
+	byte_len = strlen (nm_string);
+
+	widths = g_new (int, char_len);
+	offsets = g_new (int, byte_len);
+
+	/* Create a translation table from byte index to char offset */
+	p = nm_string;
+	i = 0;
+	while (*p) {
+		int byte_index = p - nm_string;
+
+		if (BEGINS_UTF8_CHAR (*p)) {
+			offsets[byte_index] = i;
+			++i;
+		} else {
+			offsets[byte_index] = G_MAXINT; /* segv if we try to use this */
+		}
+
+		++p;
+	}
+
+	/* Now fill in the widths array */
+	iter = pango_layout_get_iter (layout);
+
+	do {
+		PangoRectangle extents;
+		int byte_index;
+
+		byte_index = pango_layout_iter_get_index (iter);
+
+		if (byte_index < byte_len) {
+			pango_layout_iter_get_char_extents (iter, &extents);
+
+			g_assert (BEGINS_UTF8_CHAR (nm_string[byte_index]));
+			g_assert (offsets[byte_index] < char_len);
+
+			widths[offsets[byte_index]] = PANGO_PIXELS (extents.width);
+		}
+
+	} while (pango_layout_iter_next_char (iter));
+
+	pango_layout_iter_free (iter);
+
+	g_free (offsets);
+
+	*widths_return = widths;
+
+	/* Now compute character offsets that are legitimate places to
+	 * chop the string
+	 */
+	attrs = g_new (PangoLogAttr, char_len + 1);
+
+	pango_get_log_attrs (nm_string, byte_len, -1,
+			     pango_context_get_language (
+				     pango_layout_get_context (layout)),
+			     attrs,
+			     char_len + 1);
+
+	cuts = g_new (int, char_len);
+	i = 0;
+	while (i < char_len) {
+		cuts[i] = attrs[i].is_cursor_position;
+
+		++i;
+	}
+
+	g_free (attrs);
+
+	*cuts_return = cuts;
+
+	*char_len_return = char_len;
+}
+
+typedef struct
+{
+	GString *string;
+	int start_offset;
+	int end_offset;
+	int position;
+} EllipsizeStringData;
+
+static void
+start_element_handler (GMarkupParseContext *context,
+                       const gchar         *element_name,
+                       const gchar        **attribute_names,
+                       const gchar        **attribute_values,
+                       gpointer             user_data,
+                       GError             **error)
+{
+	EllipsizeStringData *data = (EllipsizeStringData *)user_data;
+	int i;
+
+	g_string_append_c (data->string, '<');
+	g_string_append (data->string, element_name);
+
+	for (i = 0; attribute_names[i] != NULL; i++)
+	{
+		g_string_append_c (data->string, ' ');
+		g_string_append (data->string, attribute_names[i]);
+		g_string_append (data->string, "=\"");
+		g_string_append (data->string, attribute_values[i]);
+		g_string_append_c (data->string, '"');
+	}
+
+	g_string_append_c (data->string, '>');
+}
+
+static void
+end_element_handler    (GMarkupParseContext *context,
+                        const gchar         *element_name,
+                        gpointer             user_data,
+                        GError             **error)
+{
+	EllipsizeStringData *data = (EllipsizeStringData *)user_data;
+
+	g_string_append (data->string, "</");
+	g_string_append (data->string, element_name);
+	g_string_append_c (data->string, '>');
+}
+
+static void
+append_ellipsized_text (const char *text,
+			EllipsizeStringData *data,
+			int text_len)
+{
+	int position;
+	int new_position;
+
+	position = data->position;
+	new_position = data->position + text_len;
+
+	if (position > data->start_offset &&
+	    new_position < data->end_offset)
+	{
+		return;
+	}
+	else if ((position < data->start_offset &&
+	          new_position < data->start_offset) ||
+	         (position > data->end_offset &&
+	          new_position > data->end_offset))
+	{
+		g_string_append (data->string,
+				text);
+	}
+	else if (position <= data->start_offset &&
+		 new_position >= data->end_offset)
+	{
+		if (position < data->start_offset)
+		{
+			g_string_append_len (data->string,
+					     text,
+					     data->start_offset -
+					     position);
+		}
+
+		g_string_append (data->string,
+				 ELLIPSIS);
+
+		if (new_position > data->end_offset)
+		{
+			g_string_append_len (data->string,
+					     text + data->end_offset -
+					     position,
+					     position + text_len -
+					     data->end_offset);
+		}
+	}
+
+	data->position = new_position;
+}
+
+static void
+text_handler           (GMarkupParseContext *context,
+                        const gchar         *text,
+                        gsize                text_len,
+                        gpointer             user_data,
+                        GError             **error)
+{
+	EllipsizeStringData *data = (EllipsizeStringData *)user_data;
+
+	append_ellipsized_text (text, data, text_len);
+}
+
+static GMarkupParser pango_markup_parser = {
+  start_element_handler,
+  end_element_handler,
+  text_handler,
+  NULL,
+  NULL
+};
+
+static char *
+ellipsize_string (const char *string,
+		  int start_offset,
+		  int end_offset,
+		  gboolean markup)
+{
+	GString *str;
+	EllipsizeStringData data;
+	char *result;
+	GMarkupParseContext *c;
+
+	str = g_string_new (NULL);
+	data.string = str;
+	data.start_offset = start_offset;
+	data.end_offset = end_offset;
+	data.position = 0;
+
+	if (markup)
+	{
+		c = g_markup_parse_context_new (&pango_markup_parser,
+					        0, &data, NULL);
+		g_markup_parse_context_parse (c, string, -1, NULL);
+		g_markup_parse_context_free (c);
+	}
+	else
+	{
+		append_ellipsized_text (string, &data,
+					g_utf8_strlen (string, -1));
+	}
+
+	result = str->str;
+	g_string_free (str, FALSE);
+	return result;
+}
+
+static char *
+ephy_string_ellipsize_start (const char *string, PangoLayout *layout, int width, gboolean markup)
+{
+	int resulting_width;
+	int *cuts;
+	int *widths;
+	int char_len;
+	int truncate_offset;
+	int bytes_end;
+
+	/* Zero-length string can't get shorter - catch this here to
+	 * avoid expensive calculations
+	 */
+	if (*string == '\0')
+		return g_strdup ("");
+
+	/* I'm not sure if this short-circuit is a net win; it might be better
+	 * to just dump this, and always do the compute_character_widths() etc.
+	 * down below.
+	 */
+	resulting_width = measure_string_width (string, layout, markup);
+
+	if (resulting_width <= width) {
+		/* String is already short enough. */
+		return g_strdup (string);
+	}
+
+	/* Remove width of an ellipsis */
+	width -= measure_string_width (ELLIPSIS, layout, markup);
+
+	if (width < 0) {
+		/* No room even for an ellipsis. */
+		return g_strdup ("");
+	}
+
+	/* Our algorithm involves removing enough chars from the string to bring
+	 * the width to the required small size. However, due to ligatures,
+	 * combining characters, etc., it's not guaranteed that the algorithm
+	 * always works 100%. It's sort of a heuristic thing. It should work
+	 * nearly all the time... but I wouldn't put in
+	 * g_assert (width of resulting string < width).
+	 *
+	 * Hmm, another thing that this breaks with is explicit line breaks
+	 * in "string"
+	 */
+
+	compute_character_widths (string, layout, &char_len, &widths, &cuts, markup);
+
+        for (truncate_offset = 1; truncate_offset < char_len; truncate_offset++) {
+
+		resulting_width -= widths[truncate_offset];
+
+		if (resulting_width <= width &&
+		    cuts[truncate_offset]) {
+			break;
+		}
+        }
+
+	g_free (cuts);
+	g_free (widths);
+
+	bytes_end = g_utf8_offset_to_pointer (string, truncate_offset) - string;
+
+	return ellipsize_string (string, 0, bytes_end, markup);
+}
+
+static char *
+ephy_string_ellipsize_end (const char *string, PangoLayout *layout, int width, gboolean markup)
+{
+	int resulting_width;
+	int *cuts;
+	int *widths;
+	int char_len;
+	int truncate_offset;
+	int bytes_end;
+
+	/* See explanatory comments in ellipsize_start */
+
+	if (*string == '\0')
+		return g_strdup ("");
+
+	resulting_width = measure_string_width (string, layout, markup);
+
+	if (resulting_width <= width) {
+		return g_strdup (string);
+	}
+
+	width -= measure_string_width (ELLIPSIS, layout, markup);
+
+	if (width < 0) {
+		return g_strdup ("");
+	}
+
+	compute_character_widths (string, layout, &char_len, &widths, &cuts, markup);
+
+        for (truncate_offset = char_len - 1; truncate_offset > 0; truncate_offset--) {
+		resulting_width -= widths[truncate_offset];
+		if (resulting_width <= width &&
+		    cuts[truncate_offset]) {
+			break;
+		}
+        }
+
+	g_free (cuts);
+	g_free (widths);
+
+	bytes_end = g_utf8_offset_to_pointer (string, truncate_offset) - string;
+
+	return ellipsize_string (string, bytes_end,
+				 char_len, markup);
+}
+
+static char *
+ephy_string_ellipsize_middle (const char *string, PangoLayout *layout, int width, gboolean markup)
+{
+	int resulting_width;
+	int *cuts;
+	int *widths;
+	int char_len;
+	int starting_fragment_length;
+	int ending_fragment_offset;
+	int bytes_start;
+	int bytes_end;
+
+	/* See explanatory comments in ellipsize_start */
+
+	if (*string == '\0')
+		return g_strdup ("");
+
+	resulting_width = measure_string_width (string, layout, markup);
+
+	if (resulting_width <= width) {
+		return g_strdup (string);
+	}
+
+	width -= measure_string_width (ELLIPSIS, layout, markup);
+
+	if (width < 0) {
+		return g_strdup ("");
+	}
+
+	compute_character_widths (string, layout, &char_len, &widths, &cuts, markup);
+
+	starting_fragment_length = char_len / 2;
+	ending_fragment_offset = starting_fragment_length + 1;
+
+	/* depending on whether the original string length is odd or even, start by
+	 * shaving off the characters from the starting or ending fragment
+	 */
+	if (char_len % 2) {
+		goto shave_end;
+	}
+
+	while (starting_fragment_length > 0 || ending_fragment_offset < char_len) {
+		if (resulting_width <= width &&
+		    cuts[ending_fragment_offset] &&
+		    cuts[starting_fragment_length]) {
+			break;
+		}
+
+		if (starting_fragment_length > 0) {
+			resulting_width -= widths[starting_fragment_length];
+			starting_fragment_length--;
+		}
+
+	shave_end:
+		if (resulting_width <= width &&
+		    cuts[ending_fragment_offset] &&
+		    cuts[starting_fragment_length]) {
+			break;
+		}
+
+		if (ending_fragment_offset < char_len) {
+			resulting_width -= widths[ending_fragment_offset];
+			ending_fragment_offset++;
+		}
+	}
+
+	g_free (cuts);
+	g_free (widths);
+
+	bytes_start = g_utf8_offset_to_pointer (string, starting_fragment_length) - string;
+	bytes_end = g_utf8_offset_to_pointer (string, ending_fragment_offset) - string;
+
+	return ellipsize_string (string, bytes_start, bytes_end, markup);
+}
+
+
+/**
+ * ephy_pango_layout_set_text_ellipsized
+ *
+ * @layout: a pango layout
+ * @string: A a string to be ellipsized.
+ * @width: Desired maximum width in points.
+ * @mode: The desired ellipsizing mode.
+ *
+ * Truncates a string if required to fit in @width and sets it on the
+ * layout. Truncation involves removing characters from the start, middle or end
+ * respectively and replacing them with "...". Algorithm is a bit
+ * fuzzy, won't work 100%.
+ *
+ */
+static void
+gul_pango_layout_set_text_ellipsized (PangoLayout  *layout,
+				      const char   *string,
+				      int           width,
+				      EphyEllipsizeMode mode,
+				      gboolean markup)
+{
+	char *s;
+
+	g_return_if_fail (PANGO_IS_LAYOUT (layout));
+	g_return_if_fail (string != NULL);
+	g_return_if_fail (width >= 0);
+
+	switch (mode) {
+	case EPHY_ELLIPSIZE_START:
+		s = ephy_string_ellipsize_start (string, layout, width, markup);
+		break;
+	case EPHY_ELLIPSIZE_MIDDLE:
+		s = ephy_string_ellipsize_middle (string, layout, width, markup);
+		break;
+	case EPHY_ELLIPSIZE_END:
+		s = ephy_string_ellipsize_end (string, layout, width, markup);
+		break;
+	default:
+		g_return_if_reached ();
+		s = NULL;
+	}
+
+	if (markup)
+	{
+		pango_layout_set_markup (layout, s, -1);
+	}
+	else
+	{
+		pango_layout_set_text (layout, s, -1);
+	}
+
+	g_free (s);
+}
+
+GType
+ephy_ellipsizing_label_get_type (void)
+{
+        static GType ephy_ellipsizing_label_type = 0;
+
+        if (ephy_ellipsizing_label_type == 0)
+        {
+                static const GTypeInfo our_info =
+                {
+                        sizeof (EphyEllipsizingLabelClass),
+                        NULL, /* base_init */
+                        NULL, /* base_finalize */
+                        (GClassInitFunc) ephy_ellipsizing_label_class_init,
+                        NULL,
+                        NULL, /* class_data */
+                        sizeof (EphyEllipsizingLabel),
+                        0, /* n_preallocs */
+                        (GInstanceInitFunc) ephy_ellipsizing_label_init
+                };
+
+                ephy_ellipsizing_label_type = g_type_register_static (GTK_TYPE_LABEL,
+								      "EphyEllipsizingLabel",
+                                                                      &our_info, 0);
+        }
+
+        return ephy_ellipsizing_label_type;
+}
+
+static void
+ephy_ellipsizing_label_init (EphyEllipsizingLabel *label)
+{
+	label->priv = g_new0 (EphyEllipsizingLabelPrivate, 1);
+
+	label->priv->mode = EPHY_ELLIPSIZE_NONE;
+}
+
+static void
+real_finalize (GObject *object)
+{
+	EphyEllipsizingLabel *label;
+
+	label = EPHY_ELLIPSIZING_LABEL (object);
+
+	g_free (label->priv->full_text);
+	g_free (label->priv);
+
+	G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+GtkWidget*
+ephy_ellipsizing_label_new (const char *string)
+{
+	EphyEllipsizingLabel *label;
+
+	label = g_object_new (EPHY_TYPE_ELLIPSIZING_LABEL, NULL);
+	ephy_ellipsizing_label_set_text (label, string);
+
+	return GTK_WIDGET (label);
+}
+
+void
+ephy_ellipsizing_label_set_text (EphyEllipsizingLabel *label,
+				 const char          *string)
+{
+	g_return_if_fail (EPHY_IS_ELLIPSIZING_LABEL (label));
+
+	if (ephy_str_is_equal (string, label->priv->full_text)) {
+		return;
+	}
+
+	g_free (label->priv->full_text);
+	label->priv->full_text = g_strdup (string);
+
+	/* Queues a resize as side effect */
+	gtk_label_set_text (GTK_LABEL (label), label->priv->full_text);
+}
+
+void
+ephy_ellipsizing_label_set_markup (EphyEllipsizingLabel *label,
+				   const char          *string)
+{
+	g_return_if_fail (EPHY_IS_ELLIPSIZING_LABEL (label));
+
+	if (ephy_str_is_equal (string, label->priv->full_text)) {
+		return;
+	}
+
+	g_free (label->priv->full_text);
+	label->priv->full_text = g_strdup (string);
+
+	/* Queues a resize as side effect */
+	gtk_label_set_markup (GTK_LABEL (label), label->priv->full_text);
+}
+
+void
+ephy_ellipsizing_label_set_mode (EphyEllipsizingLabel *label,
+		               EphyEllipsizeMode mode)
+{
+	g_return_if_fail (EPHY_IS_ELLIPSIZING_LABEL (label));
+
+	label->priv->mode = mode;
+}
+
+static void
+real_size_request (GtkWidget *widget, GtkRequisition *requisition)
+{
+	GTK_WIDGET_CLASS (parent_class)->size_request (widget, requisition);
+
+	/* Don't demand any particular width; will draw ellipsized into whatever size we're given */
+	requisition->width = 0;
+}
+
+static void
+real_size_allocate (GtkWidget *widget, GtkAllocation *allocation)
+{
+	EphyEllipsizingLabel *label;
+	gboolean markup;
+
+	markup = gtk_label_get_use_markup (GTK_LABEL (widget));
+
+	label = EPHY_ELLIPSIZING_LABEL (widget);
+
+	/* This is the bad hack of the century, using private
+	 * GtkLabel layout object. If the layout is NULL
+	 * then it got blown away since size request,
+	 * we just punt in that case, I don't know what to do really.
+	 */
+
+	if (GTK_LABEL (label)->layout != NULL) {
+		if (label->priv->full_text == NULL) {
+			pango_layout_set_text (GTK_LABEL (label)->layout, "", -1);
+		} else {
+			EphyEllipsizeMode mode;
+
+			if (label->priv->mode != EPHY_ELLIPSIZE_NONE)
+				mode = label->priv->mode;
+
+			if (ABS (GTK_MISC (label)->xalign - 0.5) < 1e-12)
+				mode = EPHY_ELLIPSIZE_MIDDLE;
+			else if (GTK_MISC (label)->xalign < 0.5)
+				mode = EPHY_ELLIPSIZE_END;
+			else
+				mode = EPHY_ELLIPSIZE_START;
+
+			gul_pango_layout_set_text_ellipsized (GTK_LABEL (label)->layout,
+							      label->priv->full_text,
+							      allocation->width,
+							      mode,
+							      markup);
+
+			gtk_widget_queue_draw (GTK_WIDGET (label));
+		}
+	}
+
+	GTK_WIDGET_CLASS (parent_class)->size_allocate (widget, allocation);
+}
+
+static gboolean
+real_expose_event (GtkWidget *widget, GdkEventExpose *event)
+{
+	EphyEllipsizingLabel *label;
+	GtkRequisition req;
+
+	label = EPHY_ELLIPSIZING_LABEL (widget);
+
+	/* push/pop the actual size so expose draws in the right
+	 * place, yes this is bad hack central. Here we assume the
+	 * ellipsized text has been set on the layout in size_allocate
+	 */
+	GTK_WIDGET_CLASS (parent_class)->size_request (widget, &req);
+	widget->requisition.width = req.width;
+	GTK_WIDGET_CLASS (parent_class)->expose_event (widget, event);
+	widget->requisition.width = 0;
+
+	return FALSE;
+}
+
+
+static void
+ephy_ellipsizing_label_class_init (EphyEllipsizingLabelClass *klass)
+{
+	GtkWidgetClass *widget_class;
+
+	parent_class = g_type_class_peek_parent (klass);
+
+	widget_class = GTK_WIDGET_CLASS (klass);
+
+	G_OBJECT_CLASS (klass)->finalize = real_finalize;
+
+	widget_class->size_request = real_size_request;
+	widget_class->size_allocate = real_size_allocate;
+	widget_class->expose_event = real_expose_event;
+}
+