path: root/libgnomecanvas/gnome-canvas-text.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
 * $Id$
 * Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation
 * All rights reserved.
 *
 * This file is part of the Gnome Library.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * published by the Free Software Foundation; either the
 *
 * This program 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 Lesser General Public License
 * License along with the Gnome Library; see the file COPYING.LIB.  If not,
 */
/*
  @NOTATION@
 */
/* Text item type for GnomeCanvas widget
 *
 * GnomeCanvas is basically a port of the Tk toolkit's most excellent canvas
 * widget.  Tk is copyrighted by the Regents of the University of California,
 * Sun Microsystems, and other parties.
 *
 *
 * Author: Federico Mena <federico@nuclecu.unam.mx>
 * Port to Pango co-done by Gergõ Érdi <cactus@cactus.rulez.org>
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <math.h>
#include <string.h>
#include "gnome-canvas-text.h"

#include "gnome-canvas-util.h"
#include "gnome-canvas-i18n.h"

/* Object argument IDs */
enum {
    PROP_0,

    /* Text contents */
    PROP_TEXT,
    PROP_MARKUP,

    /* Position */
    PROP_X,
    PROP_Y,

    /* Font */
    PROP_FONT,
    PROP_FONT_DESC,
    PROP_FAMILY, PROP_FAMILY_SET,

    /* Style */
    PROP_ATTRIBUTES,
    PROP_STYLE,         PROP_STYLE_SET,
    PROP_VARIANT,       PROP_VARIANT_SET,
    PROP_WEIGHT,        PROP_WEIGHT_SET,
    PROP_STRETCH,       PROP_STRETCH_SET,
    PROP_SIZE,          PROP_SIZE_SET,
    PROP_SIZE_POINTS,
    PROP_STRIKETHROUGH, PROP_STRIKETHROUGH_SET,
    PROP_UNDERLINE,     PROP_UNDERLINE_SET,
    PROP_RISE,          PROP_RISE_SET,
    PROP_SCALE,         PROP_SCALE_SET,

    /* Clipping */
    PROP_JUSTIFICATION,
    PROP_CLIP_WIDTH,
    PROP_CLIP_HEIGHT,
    PROP_CLIP,
    PROP_X_OFFSET,
    PROP_Y_OFFSET,

    /* Coloring */
    PROP_FILL_COLOR,
    PROP_FILL_COLOR_GDK,
    PROP_FILL_COLOR_RGBA,

    /* Rendered size accessors */
    PROP_TEXT_WIDTH,
    PROP_TEXT_HEIGHT
};

static void gnome_canvas_text_dispose (GnomeCanvasItem *object);
static void gnome_canvas_text_set_property (GObject            *object,
                        guint               param_id,
                        const GValue       *value,
                        GParamSpec         *pspec);
static void gnome_canvas_text_get_property (GObject            *object,
                        guint               param_id,
                        GValue             *value,
                        GParamSpec         *pspec);

static void gnome_canvas_text_update (GnomeCanvasItem *item,
                      const cairo_matrix_t *matrix,
                      gint flags);
static void gnome_canvas_text_draw (GnomeCanvasItem *item, cairo_t *cr,
                    gint x, gint y, gint width, gint height);
static GnomeCanvasItem *gnome_canvas_text_point (GnomeCanvasItem *item,
                                                 gdouble x,
                                                 gdouble y,
                                                 gint cx,
                                                 gint cy);
static void gnome_canvas_text_bounds (GnomeCanvasItem *item,
                      gdouble *x1, gdouble *y1, gdouble *x2, gdouble *y2);

static void gnome_canvas_text_set_markup (GnomeCanvasText *textitem,
                      const gchar     *markup);

static void gnome_canvas_text_set_font_desc    (GnomeCanvasText *textitem,
                        PangoFontDescription *font_desc);

static void gnome_canvas_text_apply_font_desc  (GnomeCanvasText *textitem);
static void gnome_canvas_text_apply_attributes (GnomeCanvasText *textitem);

static void add_attr (PangoAttrList  *attr_list,
              PangoAttribute *attr);

G_DEFINE_TYPE (
    GnomeCanvasText,
    gnome_canvas_text,
    GNOME_TYPE_CANVAS_ITEM)

/* Class initialization function for the text item */
static void
gnome_canvas_text_class_init (GnomeCanvasTextClass *class)
{
    GObjectClass *gobject_class;
    GnomeCanvasItemClass *item_class;

    gobject_class = (GObjectClass *) class;
    item_class = (GnomeCanvasItemClass *) class;

    gobject_class->set_property = gnome_canvas_text_set_property;
    gobject_class->get_property = gnome_canvas_text_get_property;

    /* Text */
    g_object_class_install_property (
        gobject_class,
        PROP_TEXT,
        g_param_spec_string (
            "text",
            "Text",
            "Text to render",
            NULL,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_MARKUP,
        g_param_spec_string (
            "markup",
            "Markup",
            "Marked up text to render",
            NULL,
            G_PARAM_WRITABLE));

    /* Position */
    g_object_class_install_property (
        gobject_class,
        PROP_X,
        g_param_spec_double (
            "x",
            NULL,
            NULL,
            -G_MAXDOUBLE,
            G_MAXDOUBLE,
            0.0,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_Y,
        g_param_spec_double (
            "y",
            NULL,
            NULL,
            -G_MAXDOUBLE,
            G_MAXDOUBLE,
            0.0,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    /* Font */
    g_object_class_install_property (
        gobject_class,
        PROP_FONT,
        g_param_spec_string (
            "font",
            "Font",
            "Font description as a string",
            NULL,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_FONT_DESC,
        g_param_spec_boxed (
            "font_desc",
            "Font description",
            "Font description as a PangoFontDescription struct",
            PANGO_TYPE_FONT_DESCRIPTION,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_FAMILY,
        g_param_spec_string (
            "family",
            "Font family",
            "Name of the font family, e.g. "
            "Sans, Helvetica, Times, Monospace",
            NULL,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    /* Style */
    g_object_class_install_property (
        gobject_class,
        PROP_ATTRIBUTES,
        g_param_spec_boxed (
            "attributes",
            NULL,
            NULL,
            PANGO_TYPE_ATTR_LIST,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_STYLE,
        g_param_spec_enum (
            "style",
            "Font style",
            "Font style",
            PANGO_TYPE_STYLE,
            PANGO_STYLE_NORMAL,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_VARIANT,
        g_param_spec_enum (
            "variant",
            "Font variant",
            "Font variant",
            PANGO_TYPE_VARIANT,
            PANGO_VARIANT_NORMAL,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_WEIGHT,
        g_param_spec_int (
            "weight",
            "Font weight",
            "Font weight",
            0,
            G_MAXINT,
            PANGO_WEIGHT_NORMAL,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_STRETCH,
        g_param_spec_enum (
            "stretch",
            "Font stretch",
            "Font stretch",
            PANGO_TYPE_STRETCH,
            PANGO_STRETCH_NORMAL,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_SIZE,
        g_param_spec_int (
            "size",
            "Font size",
            "Font size (as a multiple of PANGO_SCALE, "
            "eg. 12*PANGO_SCALE for a 12pt font size)",
            0,
            G_MAXINT,
            0,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_SIZE_POINTS,
        g_param_spec_double (
            "size_points",
            "Font points",
            "Font size in points (eg. 12 for a 12pt font size)",
            0.0,
            G_MAXDOUBLE,
            0.0,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_RISE,
        g_param_spec_int (
            "rise",
            "Rise",
            "Offset of text above the baseline "
            "(below the baseline if rise is negative)",
            -G_MAXINT,
            G_MAXINT,
            0,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_STRIKETHROUGH,
        g_param_spec_boolean (
            "strikethrough",
            "Strikethrough",
            "Whether to strike through the text",
            FALSE,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_UNDERLINE,
        g_param_spec_enum (
            "underline",
            "Underline",
            "Style of underline for this text",
            PANGO_TYPE_UNDERLINE,
            PANGO_UNDERLINE_NONE,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_SCALE,
        g_param_spec_double (
            "scale",
            "Scale",
            "Size of font, relative to default size",
            0.0,
            G_MAXDOUBLE,
            1.0,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_JUSTIFICATION,
        g_param_spec_enum (
            "justification",
            NULL,
            NULL,
            GTK_TYPE_JUSTIFICATION,
            GTK_JUSTIFY_LEFT,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_CLIP_WIDTH,
        g_param_spec_double (
            "clip_width",
            NULL,
            NULL,
            -G_MAXDOUBLE,
            G_MAXDOUBLE,
            0.0,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_CLIP_HEIGHT,
        g_param_spec_double (
            "clip_height",
            NULL,
            NULL,
            -G_MAXDOUBLE,
            G_MAXDOUBLE,
            0.0,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_CLIP,
        g_param_spec_boolean (
            "clip",
            NULL,
            NULL,
            FALSE,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_X_OFFSET,
        g_param_spec_double (
            "x_offset",
            NULL,
            NULL,
            -G_MAXDOUBLE,
            G_MAXDOUBLE,
            0.0,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_Y_OFFSET,
        g_param_spec_double (
            "y_offset",
            NULL,
            NULL,
            -G_MAXDOUBLE,
            G_MAXDOUBLE,
            0.0,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_FILL_COLOR,
        g_param_spec_string (
            "fill_color",
            "Color",
            "Text color, as string",
            NULL,
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_FILL_COLOR_GDK,
        g_param_spec_boxed (
            "fill_color_gdk",
            "Color",
            "Text color, as a GdkColor",
            GDK_TYPE_COLOR,
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_FILL_COLOR_RGBA,
        g_param_spec_uint (
            "fill_color_rgba",
            "Color",
            "Text color, as an R/G/B/A combined integer",
            0, G_MAXUINT, 0,
            G_PARAM_READABLE |
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_TEXT_WIDTH,
        g_param_spec_double (
            "text_width",
            "Text width",
            "Width of the rendered text",
            0.0, G_MAXDOUBLE, 0.0,
            G_PARAM_READABLE));

    g_object_class_install_property (
        gobject_class,
        PROP_TEXT_HEIGHT,
        g_param_spec_double (
            "text_height",
            "Text height",
            "Height of the rendered text",
            0.0, G_MAXDOUBLE, 0.0,
            G_PARAM_READABLE));

    /* Style props are set (explicitly applied) or not */
#define ADD_SET_PROP(propname, propval, nick, blurb) \
    g_object_class_install_property ( \
        gobject_class, propval, \
        g_param_spec_boolean ( \
            propname, nick, blurb, FALSE, \
            G_PARAM_READABLE | G_PARAM_WRITABLE))

    ADD_SET_PROP (
        "family_set",
        PROP_FAMILY_SET,
        "Font family set",
        "Whether this tag affects the font family");

    ADD_SET_PROP (
        "style_set",
        PROP_STYLE_SET,
        "Font style set",
        "Whether this tag affects the font style");

    ADD_SET_PROP (
        "variant_set",
        PROP_VARIANT_SET,
        "Font variant set",
        "Whether this tag affects the font variant");

    ADD_SET_PROP (
        "weight_set",
        PROP_WEIGHT_SET,
        "Font weight set",
        "Whether this tag affects the font weight");

    ADD_SET_PROP (
        "stretch_set",
        PROP_STRETCH_SET,
        "Font stretch set",
        "Whether this tag affects the font stretch");

    ADD_SET_PROP (
        "size_set",
        PROP_SIZE_SET,
        "Font size set",
        "Whether this tag affects the font size");

    ADD_SET_PROP (
        "rise_set",
        PROP_RISE_SET,
        "Rise set",
        "Whether this tag affects the rise");

    ADD_SET_PROP (
        "strikethrough_set",
        PROP_STRIKETHROUGH_SET,
        "Strikethrough set",
        "Whether this tag affects strikethrough");

    ADD_SET_PROP (
        "underline_set",
        PROP_UNDERLINE_SET,
        "Underline set",
        "Whether this tag affects underlining");

    ADD_SET_PROP (
        "scale_set",
        PROP_SCALE_SET,
        "Scale set",
        "Whether this tag affects font scaling");
#undef ADD_SET_PROP

    item_class->dispose = gnome_canvas_text_dispose;
    item_class->update = gnome_canvas_text_update;
    item_class->draw = gnome_canvas_text_draw;
    item_class->point = gnome_canvas_text_point;
    item_class->bounds = gnome_canvas_text_bounds;
}

/* Object initialization function for the text item */
static void
gnome_canvas_text_init (GnomeCanvasText *text)
{
    text->x = 0.0;
    text->y = 0.0;
    text->justification = GTK_JUSTIFY_LEFT;
    text->clip_width = 0.0;
    text->clip_height = 0.0;
    text->xofs = 0.0;
    text->yofs = 0.0;
    text->layout = NULL;

    text->font_desc = NULL;

    text->underline = PANGO_UNDERLINE_NONE;
    text->strikethrough = FALSE;
    text->rise = 0;

    text->underline_set = FALSE;
    text->strike_set = FALSE;
    text->rise_set = FALSE;
}

/* Dispose handler for the text item */
static void
gnome_canvas_text_dispose (GnomeCanvasItem *object)
{
    GnomeCanvasText *text;

    g_return_if_fail (GNOME_IS_CANVAS_TEXT (object));

    text = GNOME_CANVAS_TEXT (object);

    g_free (text->text);
    text->text = NULL;

    if (text->layout != NULL) {
        g_object_unref (text->layout);
        text->layout = NULL;
    }

    if (text->font_desc != NULL) {
        pango_font_description_free (text->font_desc);
        text->font_desc = NULL;
    }

    if (text->attr_list != NULL) {
        pango_attr_list_unref (text->attr_list);
        text->attr_list = NULL;
    }

    GNOME_CANVAS_ITEM_CLASS (gnome_canvas_text_parent_class)->
        dispose (object);
}

static void
get_bounds (GnomeCanvasText *text,
            gdouble *px1,
            gdouble *py1,
            gdouble *px2,
            gdouble *py2)
{
    GnomeCanvasItem *item;
    gdouble wx, wy;

    item = GNOME_CANVAS_ITEM (text);

    /* Get canvas pixel coordinates for text position */

    wx = text->x;
    wy = text->y;
    gnome_canvas_item_i2w (item, &wx, &wy);
    gnome_canvas_w2c (
        item->canvas, wx + text->xofs, wy + text->yofs,
        &text->cx, &text->cy);

    /* Get canvas pixel coordinates for clip rectangle position */

    gnome_canvas_w2c (item->canvas, wx, wy, &text->clip_cx, &text->clip_cy);
    text->clip_cwidth = text->clip_width;
    text->clip_cheight = text->clip_height;

    /* Bounds */

    if (text->clip) {
        *px1 = text->clip_cx;
        *py1 = text->clip_cy;
        *px2 = text->clip_cx + text->clip_cwidth;
        *py2 = text->clip_cy + text->clip_cheight;
    } else {
        *px1 = text->cx;
        *py1 = text->cy;
        *px2 = text->cx + text->max_width;
        *py2 = text->cy + text->height;
    }
}

static PangoFontMask
get_property_font_set_mask (guint property_id)
{
    switch (property_id) {
        case PROP_FAMILY_SET:
            return PANGO_FONT_MASK_FAMILY;
        case PROP_STYLE_SET:
            return PANGO_FONT_MASK_STYLE;
        case PROP_VARIANT_SET:
            return PANGO_FONT_MASK_VARIANT;
        case PROP_WEIGHT_SET:
            return PANGO_FONT_MASK_WEIGHT;
        case PROP_STRETCH_SET:
            return PANGO_FONT_MASK_STRETCH;
        case PROP_SIZE_SET:
            return PANGO_FONT_MASK_SIZE;
    }

    return 0;
}

static void
ensure_font (GnomeCanvasText *text)
{
    if (!text->font_desc)
        text->font_desc = pango_font_description_new ();
}

/* Set_arg handler for the text item */
static void
gnome_canvas_text_set_property (GObject *object,
                                guint param_id,
                                const GValue *value,
                                GParamSpec *pspec)
{
    GnomeCanvasItem *item;
    GnomeCanvasText *text;
    GdkColor *pcolor;
    PangoAlignment align;

    g_return_if_fail (object != NULL);
    g_return_if_fail (GNOME_IS_CANVAS_TEXT (object));

    item = GNOME_CANVAS_ITEM (object);
    text = GNOME_CANVAS_TEXT (object);

    if (!text->layout)
        text->layout = pango_layout_new (
            gtk_widget_get_pango_context (
            GTK_WIDGET (item->canvas)));

    switch (param_id) {
    case PROP_TEXT:
        g_free (text->text);

        text->text = g_value_dup_string (value);
        pango_layout_set_text (text->layout, text->text, -1);

        break;

    case PROP_MARKUP:
        gnome_canvas_text_set_markup (
            text, g_value_get_string (value));
        break;

    case PROP_X:
        text->x = g_value_get_double (value);
        break;

    case PROP_Y:
        text->y = g_value_get_double (value);
        break;

    case PROP_FONT: {
        const gchar *font_name;
        PangoFontDescription *font_desc;

        font_name = g_value_get_string (value);
        if (font_name)
            font_desc = pango_font_description_from_string (font_name);
        else
            font_desc = NULL;

        gnome_canvas_text_set_font_desc (text, font_desc);
        if (font_desc)
            pango_font_description_free (font_desc);

        break;
    }

    case PROP_FONT_DESC:
        gnome_canvas_text_set_font_desc (text, g_value_peek_pointer (value));
        break;

    case PROP_FAMILY:
    case PROP_STYLE:
    case PROP_VARIANT:
    case PROP_WEIGHT:
    case PROP_STRETCH:
    case PROP_SIZE:
    case PROP_SIZE_POINTS:
        ensure_font (text);

        switch (param_id) {
        case PROP_FAMILY:
            pango_font_description_set_family (
                text->font_desc,
                g_value_get_string (value));
            break;
        case PROP_STYLE:
            pango_font_description_set_style (
                text->font_desc,
                g_value_get_enum (value));
            break;
        case PROP_VARIANT:
            pango_font_description_set_variant (
                text->font_desc,
                g_value_get_enum (value));
            break;
        case PROP_WEIGHT:
            pango_font_description_set_weight (
                text->font_desc,
                g_value_get_int (value));
            break;
        case PROP_STRETCH:
            pango_font_description_set_stretch (
                text->font_desc,
                g_value_get_enum (value));
            break;
        case PROP_SIZE:
            /* FIXME: This is bogus! It should be pixels, not points/PANGO_SCALE! */
            pango_font_description_set_size (
                text->font_desc,
                g_value_get_int (value));
            break;
        case PROP_SIZE_POINTS:
            pango_font_description_set_size (
                text->font_desc,
                g_value_get_double (value) * PANGO_SCALE);
            break;
        }

        gnome_canvas_text_apply_font_desc (text);
        break;

    case PROP_FAMILY_SET:
    case PROP_STYLE_SET:
    case PROP_VARIANT_SET:
    case PROP_WEIGHT_SET:
    case PROP_STRETCH_SET:
    case PROP_SIZE_SET:
        if (!g_value_get_boolean (value) && text->font_desc)
            pango_font_description_unset_fields (
                text->font_desc,
                get_property_font_set_mask (param_id));
        break;

    case PROP_SCALE:
        text->scale = g_value_get_double (value);
        text->scale_set = TRUE;

        gnome_canvas_text_apply_font_desc (text);
        break;

    case PROP_SCALE_SET:
        text->scale_set = g_value_get_boolean (value);

        gnome_canvas_text_apply_font_desc (text);
        break;

    case PROP_UNDERLINE:
        text->underline = g_value_get_enum (value);
        text->underline_set = TRUE;

        gnome_canvas_text_apply_attributes (text);
        break;

    case PROP_UNDERLINE_SET:
        text->underline_set = g_value_get_boolean (value);

        gnome_canvas_text_apply_attributes (text);
        break;

    case PROP_STRIKETHROUGH:
        text->strikethrough = g_value_get_boolean (value);
        text->strike_set = TRUE;

        gnome_canvas_text_apply_attributes (text);
        break;

    case PROP_STRIKETHROUGH_SET:
        text->strike_set = g_value_get_boolean (value);

        gnome_canvas_text_apply_attributes (text);
        break;

    case PROP_RISE:
        text->rise = g_value_get_int (value);
        text->rise_set = TRUE;

        gnome_canvas_text_apply_attributes (text);
        break;

    case PROP_RISE_SET:
        text->rise_set = TRUE;

        gnome_canvas_text_apply_attributes (text);
        break;

    case PROP_ATTRIBUTES:
        if (text->attr_list)
            pango_attr_list_unref (text->attr_list);

        text->attr_list = g_value_peek_pointer (value);
        pango_attr_list_ref (text->attr_list);

        gnome_canvas_text_apply_attributes (text);
        break;

    case PROP_JUSTIFICATION:
        text->justification = g_value_get_enum (value);

        switch (text->justification) {
        case GTK_JUSTIFY_LEFT:
            align = PANGO_ALIGN_LEFT;
            break;
        case GTK_JUSTIFY_CENTER:
            align = PANGO_ALIGN_CENTER;
            break;
        case GTK_JUSTIFY_RIGHT:
            align = PANGO_ALIGN_RIGHT;
            break;
        default:
            /* GTK_JUSTIFY_FILL isn't supported yet. */
            align = PANGO_ALIGN_LEFT;
            break;
        }
        pango_layout_set_alignment (text->layout, align);
        break;

    case PROP_CLIP_WIDTH:
        text->clip_width = fabs (g_value_get_double (value));
        break;

    case PROP_CLIP_HEIGHT:
        text->clip_height = fabs (g_value_get_double (value));
        break;

    case PROP_CLIP:
        text->clip = g_value_get_boolean (value);
        break;

    case PROP_X_OFFSET:
        text->xofs = g_value_get_double (value);
        break;

    case PROP_Y_OFFSET:
        text->yofs = g_value_get_double (value);
        break;

    case PROP_FILL_COLOR: {
        const gchar *color_name;

        color_name = g_value_get_string (value);
        if (color_name) {
            GdkColor color;
            if (gdk_color_parse (color_name, &color)) {
                text->rgba = ((color.red & 0xff00) << 16 |
                          (color.green & 0xff00) << 8 |
                          (color.blue & 0xff00) |
                          0xff);
            } else {
                g_warning (
                    "%s: Failed to parse color form string '%s'",
                    G_STRFUNC, color_name);
            }
        }
        break;
    }

    case PROP_FILL_COLOR_GDK:
        pcolor = g_value_get_boxed (value);
        if (pcolor) {
            text->rgba = ((pcolor->red & 0xff00) << 16 |
                      (pcolor->green & 0xff00) << 8|
                      (pcolor->blue & 0xff00) |
                      0xff);
        } else {
            text->rgba = 0;
        }
        break;

    case PROP_FILL_COLOR_RGBA:
        text->rgba = g_value_get_uint (value);
        break;

    default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID (object, param_id, pspec);
        break;
    }

    /* Calculate text dimensions */

    if (text->layout)
        pango_layout_get_pixel_size (
            text->layout,
            &text->max_width,
            &text->height);
    else {
        text->max_width = 0;
        text->height = 0;
    }

    gnome_canvas_item_request_update (item);
}

/* Get_arg handler for the text item */
static void
gnome_canvas_text_get_property (GObject *object,
                                guint param_id,
                                GValue *value,
                                GParamSpec *pspec)
{
    GnomeCanvasText *text;

    g_return_if_fail (object != NULL);
    g_return_if_fail (GNOME_IS_CANVAS_TEXT (object));

    text = GNOME_CANVAS_TEXT (object);

    switch (param_id) {
    case PROP_TEXT:
        g_value_set_string (value, text->text);
        break;

    case PROP_X:
        g_value_set_double (value, text->x);
        break;

    case PROP_Y:
        g_value_set_double (value, text->y);
        break;

    case PROP_FONT:
    case PROP_FONT_DESC:
    case PROP_FAMILY:
    case PROP_STYLE:
    case PROP_VARIANT:
    case PROP_WEIGHT:
    case PROP_STRETCH:
    case PROP_SIZE:
    case PROP_SIZE_POINTS:
        ensure_font (text);

        switch (param_id) {
        case PROP_FONT:
        {
            /* FIXME GValue imposes a totally gratuitous string
             *       copy here, we could just hand off string
             *       ownership. */
            gchar *str;

            str = pango_font_description_to_string (text->font_desc);
            g_value_set_string (value, str);
            g_free (str);

            break;
        }

        case PROP_FONT_DESC:
            g_value_set_boxed (value, text->font_desc);
            break;

        case PROP_FAMILY:
            g_value_set_string (
                value,
                pango_font_description_get_family (
                text->font_desc));
            break;

        case PROP_STYLE:
            g_value_set_enum (
                value,
                pango_font_description_get_style (
                text->font_desc));
            break;

        case PROP_VARIANT:
            g_value_set_enum (
                value,
                pango_font_description_get_variant (
                text->font_desc));
            break;

        case PROP_WEIGHT:
            g_value_set_int (
                value,
                pango_font_description_get_weight (
                text->font_desc));
            break;

        case PROP_STRETCH:
            g_value_set_enum (
                value,
                pango_font_description_get_stretch (
                text->font_desc));
            break;

        case PROP_SIZE:
            g_value_set_int (
                value,
                pango_font_description_get_size (
                text->font_desc));
            break;

        case PROP_SIZE_POINTS:
            g_value_set_double (
                value, ((gdouble)
                pango_font_description_get_size (
                text->font_desc)) / (gdouble) PANGO_SCALE);
            break;
        }
        break;

    case PROP_FAMILY_SET:
    case PROP_STYLE_SET:
    case PROP_VARIANT_SET:
    case PROP_WEIGHT_SET:
    case PROP_STRETCH_SET:
    case PROP_SIZE_SET:
    {
        PangoFontMask set_mask = text->font_desc ?
            pango_font_description_get_set_fields (text->font_desc) : 0;
        PangoFontMask test_mask = get_property_font_set_mask (param_id);
        g_value_set_boolean (value, (set_mask & test_mask) != 0);

        break;
    }

    case PROP_SCALE:
        g_value_set_double (value, text->scale);
        break;
    case PROP_SCALE_SET:
        g_value_set_boolean (value, text->scale_set);
        break;

    case PROP_UNDERLINE:
        g_value_set_enum (value, text->underline);
        break;
    case PROP_UNDERLINE_SET:
        g_value_set_boolean (value, text->underline_set);
        break;

    case PROP_STRIKETHROUGH:
        g_value_set_boolean (value, text->strikethrough);
        break;
    case PROP_STRIKETHROUGH_SET:
        g_value_set_boolean (value, text->strike_set);
        break;

    case PROP_RISE:
        g_value_set_int (value, text->rise);
        break;
    case PROP_RISE_SET:
        g_value_set_boolean (value, text->rise_set);
        break;

    case PROP_ATTRIBUTES:
        g_value_set_boxed (value, text->attr_list);
        break;

    case PROP_JUSTIFICATION:
        g_value_set_enum (value, text->justification);
        break;

    case PROP_CLIP_WIDTH:
        g_value_set_double (value, text->clip_width);
        break;

    case PROP_CLIP_HEIGHT:
        g_value_set_double (value, text->clip_height);
        break;

    case PROP_CLIP:
        g_value_set_boolean (value, text->clip);
        break;

    case PROP_X_OFFSET:
        g_value_set_double (value, text->xofs);
        break;

    case PROP_Y_OFFSET:
        g_value_set_double (value, text->yofs);
        break;

    case PROP_FILL_COLOR_RGBA:
        g_value_set_uint (value, text->rgba);
        break;

    case PROP_TEXT_WIDTH:
        g_value_set_double (value, text->max_width);
        break;

    case PROP_TEXT_HEIGHT:
        g_value_set_double (value, text->height);
        break;

    default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID (object, param_id, pspec);
        break;
    }
}

/* */
static void
gnome_canvas_text_apply_font_desc (GnomeCanvasText *text)
{
    PangoFontDescription *font_desc;
    PangoContext *pango_context;
    GtkWidget *widget;

    widget = GTK_WIDGET (GNOME_CANVAS_ITEM (text)->canvas);
    pango_context = gtk_widget_create_pango_context (widget);
    font_desc = pango_font_description_copy (pango_context_get_font_description (pango_context));
    g_object_unref (pango_context);

    if (text->font_desc)
        pango_font_description_merge (font_desc, text->font_desc, TRUE);

    pango_layout_set_font_description (text->layout, font_desc);
    pango_font_description_free (font_desc);
}

static void
add_attr (PangoAttrList *attr_list,
          PangoAttribute *attr)
{
    attr->start_index = 0;
    attr->end_index = G_MAXINT;

    pango_attr_list_insert (attr_list, attr);
}

/* */
static void
gnome_canvas_text_apply_attributes (GnomeCanvasText *text)
{
    PangoAttrList *attr_list;

    if (text->attr_list)
        attr_list = pango_attr_list_copy (text->attr_list);
    else
        attr_list = pango_attr_list_new ();

    if (text->underline_set)
        add_attr (attr_list, pango_attr_underline_new (text->underline));
    if (text->strike_set)
        add_attr (attr_list, pango_attr_strikethrough_new (text->strikethrough));
    if (text->rise_set)
        add_attr (attr_list, pango_attr_rise_new (text->rise));

    pango_layout_set_attributes (text->layout, attr_list);
    pango_attr_list_unref (attr_list);
}

static void
gnome_canvas_text_set_font_desc (GnomeCanvasText *text,
                                 PangoFontDescription *font_desc)
{
    if (text->font_desc)
        pango_font_description_free (text->font_desc);

    if (font_desc)
        text->font_desc = pango_font_description_copy (font_desc);
    else
        text->font_desc = NULL;

    gnome_canvas_text_apply_font_desc (text);
}

/* Setting the text from a Pango markup string */
static void
gnome_canvas_text_set_markup (GnomeCanvasText *textitem,
                              const gchar *markup)
{
    PangoAttrList *attr_list = NULL;
    gchar         *text = NULL;
    GError        *error = NULL;

    if (markup && !pango_parse_markup (markup, -1,
                       0,
                       &attr_list, &text, NULL,
                       &error))
    {
        g_warning (
            "Failed to set cell text from markup due to "
            "error parsing markup: %s", error->message);
        g_error_free (error);
        return;
    }

    g_free (textitem->text);
    if (textitem->attr_list)
        pango_attr_list_unref (textitem->attr_list);

    textitem->text = text;
    textitem->attr_list = attr_list;

    pango_layout_set_text (textitem->layout, text, -1);

    gnome_canvas_text_apply_attributes (textitem);
}

/* Update handler for the text item */
static void
gnome_canvas_text_update (GnomeCanvasItem *item,
                          const cairo_matrix_t *matrix,
                          gint flags)
{
    GnomeCanvasText *text;
    gdouble x1, y1, x2, y2;

    text = GNOME_CANVAS_TEXT (item);

    GNOME_CANVAS_ITEM_CLASS (gnome_canvas_text_parent_class)->
        update (item, matrix, flags);

    get_bounds (text, &x1, &y1, &x2, &y2);

    gnome_canvas_update_bbox (
        item,
        floor (x1), floor (y1),
        ceil (x2), ceil (y2));
}

/* Draw handler for the text item */
static void
gnome_canvas_text_draw (GnomeCanvasItem *item,
                        cairo_t *cr,
                        gint x,
                        gint y,
                        gint width,
                        gint height)
{
    GnomeCanvasText *text = GNOME_CANVAS_TEXT (item);

    if (!text->text)
        return;

    cairo_save (cr);

    if (text->clip) {
        cairo_rectangle (
            cr,
            text->clip_cx - x,
            text->clip_cy - y,
            text->clip_cwidth,
            text->clip_cheight);
        cairo_clip (cr);
    }

    cairo_set_source_rgba (
        cr,
        ((text->rgba >> 24) & 0xff) / 255.0,
        ((text->rgba >> 16) & 0xff) / 255.0,
        ((text->rgba >> 8) & 0xff) / 255.0,
        ( text->rgba & 0xff) / 255.0);

    cairo_move_to (cr, text->cx - x, text->cy - y);
    pango_cairo_show_layout (cr, text->layout);

    cairo_restore (cr);
}

/* Point handler for the text item */
static GnomeCanvasItem *
gnome_canvas_text_point (GnomeCanvasItem *item,
                         gdouble x,
                         gdouble y,
                         gint cx,
                         gint cy)
{
    GnomeCanvasText *text;
    PangoLayoutIter *iter;
    gint x1, y1, x2, y2;

    text = GNOME_CANVAS_TEXT (item);

    /* The idea is to build bounding rectangles for each of the lines of
     * text (clipped by the clipping rectangle, if it is activated) and see
     * whether the point is inside any of these.  If it is, we are done.
     * Otherwise, calculate the distance to the nearest rectangle.
     */

    iter = pango_layout_get_iter (text->layout);
    do {
        PangoRectangle log_rect;

        pango_layout_iter_get_line_extents (iter, NULL, &log_rect);

        x1 = text->cx + PANGO_PIXELS (log_rect.x);
        y1 = text->cy + PANGO_PIXELS (log_rect.y);
        x2 = x1 + PANGO_PIXELS (log_rect.width);
        y2 = y1 + PANGO_PIXELS (log_rect.height);

        if (text->clip) {
            if (x1 < text->clip_cx)
                x1 = text->clip_cx;

            if (y1 < text->clip_cy)
                y1 = text->clip_cy;

            if (x2 > (text->clip_cx + text->clip_width))
                x2 = text->clip_cx + text->clip_width;

            if (y2 > (text->clip_cy + text->clip_height))
                y2 = text->clip_cy + text->clip_height;

            if ((x1 >= x2) || (y1 >= y2))
                continue;
        }

        /* Calculate distance from point to rectangle */

        if (cx >= x1 && cx < x2 && cy >= y1 && cy < y2) {
            pango_layout_iter_free (iter);
            return item;
        }

    } while (pango_layout_iter_next_line (iter));

    pango_layout_iter_free (iter);

    return NULL;
}

/* Bounds handler for the text item */
static void
gnome_canvas_text_bounds (GnomeCanvasItem *item,
                          gdouble *x1,
                          gdouble *y1,
                          gdouble *x2,
                          gdouble *y2)
{
    GnomeCanvasText *text;
    gdouble width, height;

    text = GNOME_CANVAS_TEXT (item);

    *x1 = text->x;
    *y1 = text->y;

    if (text->clip) {
        width = text->clip_width;
        height = text->clip_height;
    } else {
        width = text->max_width;
        height = text->height;
    }

    *x2 = *x1 + width;
    *y2 = *y1 + height;
}