gtk2/gtk/gtkiconhelper.c

/* GTK - The GIMP Toolkit
 * Copyright (C) 2011 Red Hat, Inc.
 *
 * Authors: Cosimo Cecchi <cosimoc@gnome.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library. If not, see <http://www.gnu.org/licenses/>.
 */

#include "config.h"

#include "gtkiconhelperprivate.h"

#include <math.h>

#include "gtkcssenumvalueprivate.h"
#include "gtkcssiconthemevalueprivate.h"
#include "gtkcssnodeprivate.h"
#include "gtkcssnumbervalueprivate.h"
#include "gtkcssstyleprivate.h"
#include "gtkcssstylepropertyprivate.h"
#include "gtkcsstransientnodeprivate.h"
#include "gtkiconthemeprivate.h"
#include "gtkrendericonprivate.h"
#include "gtkscalerprivate.h"
#include "gtksnapshot.h"
#include "gtkwidgetprivate.h"

struct _GtkIconHelper
{
  GObject parent_instance;

  GtkImageDefinition *def;

  gint pixel_size;

  guint use_fallback : 1;
  guint force_scale_pixbuf : 1;
  guint texture_is_symbolic : 1;

  GtkWidget *owner;
  GtkCssNode *node;
  GdkPaintable *paintable;
};

static int
get_default_size (GtkIconHelper *self)
{
  GtkCssStyle *style;

  if (self->pixel_size != -1)
    return self->pixel_size;

  style = gtk_css_node_get_style (self->node);
  return _gtk_css_number_value_get (gtk_css_style_get_value (style, GTK_CSS_PROPERTY_ICON_SIZE), 100);
}

static GtkIconLookupFlags
get_icon_lookup_flags (GtkIconHelper    *self,
                       GtkCssStyle      *style,
                       GtkTextDirection  dir)
{
  GtkIconLookupFlags flags;
  GtkCssIconStyle icon_style;

  flags = GTK_ICON_LOOKUP_USE_BUILTIN;

  if (self->pixel_size != -1 || self->force_scale_pixbuf)
    flags |= GTK_ICON_LOOKUP_FORCE_SIZE;

  icon_style = _gtk_css_icon_style_value_get (gtk_css_style_get_value (style, GTK_CSS_PROPERTY_ICON_STYLE));

  switch (icon_style)
    {
    case GTK_CSS_ICON_STYLE_REGULAR:
      flags |= GTK_ICON_LOOKUP_FORCE_REGULAR;
      break;
    case GTK_CSS_ICON_STYLE_SYMBOLIC:
      flags |= GTK_ICON_LOOKUP_FORCE_SYMBOLIC;
      break;
    case GTK_CSS_ICON_STYLE_REQUESTED:
      break;
    default:
      g_assert_not_reached ();
      return 0;
    }

  if (dir == GTK_TEXT_DIR_LTR)
    flags |= GTK_ICON_LOOKUP_DIR_LTR;
  else if (dir == GTK_TEXT_DIR_RTL)
    flags |= GTK_ICON_LOOKUP_DIR_RTL;

  return flags;
}

static GdkPaintable *
ensure_paintable_for_gicon (GtkIconHelper    *self,
                            GtkCssStyle      *style,
                            GtkTextDirection  dir,
                            gint              scale,
                            GIcon            *gicon,
                            gboolean         *symbolic)
{
  GtkIconTheme *icon_theme;
  gint width, height;
  GtkIconInfo *info;
  GtkIconLookupFlags flags;
  GdkPaintable *paintable;

  icon_theme = gtk_css_icon_theme_value_get_icon_theme
    (gtk_css_style_get_value (style, GTK_CSS_PROPERTY_ICON_THEME));
  flags = get_icon_lookup_flags (self, style, dir);

  width = height = get_default_size (self);

  info = gtk_icon_theme_lookup_by_gicon_for_scale (icon_theme,
                                                   gicon,
                                                   MIN (width, height),
                                                   scale, flags);
  if (info == NULL)
    info = gtk_icon_theme_lookup_icon (icon_theme,
                                       "image-missing",
                                       width,
                                       flags | GTK_ICON_LOOKUP_USE_BUILTIN | GTK_ICON_LOOKUP_GENERIC_FALLBACK);

  *symbolic = gtk_icon_info_is_symbolic (info);
  paintable = GDK_PAINTABLE (gtk_icon_info_load_texture (info));
  if (paintable && scale != 1)
    {
      GdkPaintable *orig = paintable;

      paintable = gtk_scaler_new (orig, scale);
      g_object_unref (orig);
    }

  return paintable;
}

static GdkPaintable *
gtk_icon_helper_load_paintable (GtkIconHelper   *self,
                                gboolean        *out_symbolic)
{
  GdkPaintable *paintable;
  GIcon *gicon;
  gboolean symbolic;

  switch (gtk_image_definition_get_storage_type (self->def))
    {
    case GTK_IMAGE_PAINTABLE:
      paintable = g_object_ref (gtk_image_definition_get_paintable (self->def));
      symbolic = FALSE;
      break;

    case GTK_IMAGE_ICON_NAME:
      if (self->use_fallback)
        gicon = g_themed_icon_new_with_default_fallbacks (gtk_image_definition_get_icon_name (self->def));
      else
        gicon = g_themed_icon_new (gtk_image_definition_get_icon_name (self->def));
      paintable = ensure_paintable_for_gicon (self,
                                              gtk_css_node_get_style (self->node),
                                              gtk_widget_get_direction (self->owner),
                                              gtk_widget_get_scale_factor (self->owner),
                                              gicon,
                                              &symbolic);
      g_object_unref (gicon);
      break;

    case GTK_IMAGE_GICON:
      paintable = ensure_paintable_for_gicon (self, 
                                              gtk_css_node_get_style (self->node),
                                              gtk_widget_get_direction (self->owner),
                                              gtk_widget_get_scale_factor (self->owner),
                                              gtk_image_definition_get_gicon (self->def),
                                              &symbolic);
      break;

    case GTK_IMAGE_EMPTY:
    default:
      paintable = NULL;
      symbolic = FALSE;
      break;
    }

  *out_symbolic = symbolic;

  return paintable;
}

static void
gtk_icon_helper_ensure_paintable (GtkIconHelper *self)
{
  gboolean symbolic;

  if (self->paintable)
    return;

  self->paintable = gtk_icon_helper_load_paintable (self, &symbolic);
  self->texture_is_symbolic = symbolic;
}

static void
gtk_icon_helper_paintable_snapshot (GdkPaintable *paintable,
                                    GdkSnapshot  *snapshot,
                                    double        width,
                                    double        height)
{
  GtkIconHelper *self = GTK_ICON_HELPER (paintable);
  GtkCssStyle *style;

  style = gtk_css_node_get_style (self->node);

  gtk_icon_helper_ensure_paintable (self);
  if (self->paintable == NULL)
    return;

  switch (gtk_image_definition_get_storage_type (self->def))
    {
    case GTK_IMAGE_ICON_NAME:
    case GTK_IMAGE_GICON:
      {
        double x, y, w, h;

        /* Never scale up icons. */
        w = gdk_paintable_get_intrinsic_width (self->paintable);
        h = gdk_paintable_get_intrinsic_height (self->paintable);
        w = MIN (w, width);
        h = MIN (h, height);
        x = (width - w) / 2;
        y = (height - h) / 2;
        gtk_snapshot_offset (snapshot, x, y);
        gtk_css_style_snapshot_icon_paintable (style,
                                               snapshot,
                                               self->paintable,
                                               w, h,
                                               self->texture_is_symbolic);
        gtk_snapshot_offset (snapshot, -x, -y);
      }
      break;

    case GTK_IMAGE_PAINTABLE:
    case GTK_IMAGE_EMPTY:
    default:
      gtk_css_style_snapshot_icon_paintable (style,
                                             snapshot,
                                             self->paintable,
                                             width, height,
                                             self->texture_is_symbolic);
      break;
    }
}

static GdkPaintable *
gtk_icon_helper_paintable_get_current_image (GdkPaintable *paintable)
{
  GtkIconHelper *self = GTK_ICON_HELPER (paintable);

  gtk_icon_helper_ensure_paintable (self);
  if (self->paintable == NULL)
    return NULL;

  return gtk_icon_helper_paintable_get_current_image (self->paintable);
}

static int
gtk_icon_helper_paintable_get_intrinsic_width (GdkPaintable *paintable)
{
  GtkIconHelper *self = GTK_ICON_HELPER (paintable);

  switch (gtk_image_definition_get_storage_type (self->def))
    {
    case GTK_IMAGE_PAINTABLE:
      return gdk_paintable_get_intrinsic_width (gtk_image_definition_get_paintable (self->def));

    case GTK_IMAGE_ICON_NAME:
    case GTK_IMAGE_GICON:
      if (self->pixel_size != -1 || self->force_scale_pixbuf)
        return get_default_size (self);
      gtk_icon_helper_ensure_paintable (self);
      if (self->paintable)
        return gdk_paintable_get_intrinsic_width (self->paintable);
      else
        return 0;

    case GTK_IMAGE_EMPTY:
      return 0;

    default:
      g_assert_not_reached ();
      return 0;
    }
}

static int
gtk_icon_helper_paintable_get_intrinsic_height (GdkPaintable *paintable)
{
  GtkIconHelper *self = GTK_ICON_HELPER (paintable);

  switch (gtk_image_definition_get_storage_type (self->def))
    {
    case GTK_IMAGE_PAINTABLE:
      return gdk_paintable_get_intrinsic_height (gtk_image_definition_get_paintable (self->def));

    case GTK_IMAGE_ICON_NAME:
    case GTK_IMAGE_GICON:
      if (self->pixel_size != -1 || self->force_scale_pixbuf)
        return get_default_size (self);
      gtk_icon_helper_ensure_paintable (self);
      if (self->paintable)
        return gdk_paintable_get_intrinsic_height (self->paintable);
      else
        return 0;

    case GTK_IMAGE_EMPTY:
      return 0;

    default:
      g_assert_not_reached ();
      return 0;
    }
}

static double gtk_icon_helper_paintable_get_intrinsic_aspect_ratio (GdkPaintable *paintable)
{
  GtkIconHelper *self = GTK_ICON_HELPER (paintable);

  switch (gtk_image_definition_get_storage_type (self->def))
    {
    case GTK_IMAGE_PAINTABLE:
      return gdk_paintable_get_intrinsic_aspect_ratio (gtk_image_definition_get_paintable (self->def));

    case GTK_IMAGE_ICON_NAME:
    case GTK_IMAGE_GICON:
      return 1.0;

    case GTK_IMAGE_EMPTY:
      return 0.0;

    default:
      g_assert_not_reached ();
      return 0.0;
    }
};

static void
gtk_icon_helper_paintable_init (GdkPaintableInterface *iface)
{
  iface->snapshot = gtk_icon_helper_paintable_snapshot;
  iface->get_current_image = gtk_icon_helper_paintable_get_current_image;
  iface->get_intrinsic_width = gtk_icon_helper_paintable_get_intrinsic_width;
  iface->get_intrinsic_height = gtk_icon_helper_paintable_get_intrinsic_height;
  iface->get_intrinsic_aspect_ratio = gtk_icon_helper_paintable_get_intrinsic_aspect_ratio;
}

G_DEFINE_TYPE_WITH_CODE (GtkIconHelper, gtk_icon_helper, G_TYPE_OBJECT,
			 G_IMPLEMENT_INTERFACE (GDK_TYPE_PAINTABLE,
						gtk_icon_helper_paintable_init))

void
gtk_icon_helper_invalidate (GtkIconHelper *self)
{
  g_clear_object (&self->paintable);
  self->texture_is_symbolic = FALSE;

  if (!GTK_IS_CSS_TRANSIENT_NODE (self->node))
    gtk_widget_queue_resize (self->owner);
}

void
gtk_icon_helper_invalidate_for_change (GtkIconHelper     *self,
                                       GtkCssStyleChange *change)
{
  if (change == NULL ||
      ((gtk_css_style_change_affects (change, GTK_CSS_AFFECTS_SYMBOLIC_ICON) &&
        self->texture_is_symbolic) ||
       (gtk_css_style_change_affects (change, GTK_CSS_AFFECTS_ICON) &&
        !self->texture_is_symbolic)))
    {
      /* Avoid the queue_resize in gtk_icon_helper_invalidate */
      g_clear_object (&self->paintable);
      self->texture_is_symbolic = FALSE;

      if (change == NULL ||
          (gtk_css_style_change_affects (change, GTK_CSS_AFFECTS_ICON_SIZE) &&
          !GTK_IS_CSS_TRANSIENT_NODE (self->node)))
        gtk_widget_queue_resize (self->owner);
    }
}

static void
gtk_icon_helper_take_definition (GtkIconHelper      *self,
                                 GtkImageDefinition *def)
{
  _gtk_icon_helper_clear (self);

  if (def == NULL)
    return;

  gtk_image_definition_unref (self->def);
  self->def = def;

  gtk_icon_helper_invalidate (self);
}

void
_gtk_icon_helper_clear (GtkIconHelper *self)
{
  g_clear_object (&self->paintable);
  self->texture_is_symbolic = FALSE;

  if (gtk_image_definition_get_storage_type (self->def) != GTK_IMAGE_EMPTY)
    {
      gtk_image_definition_unref (self->def);
      self->def = gtk_image_definition_new_empty ();
      gtk_icon_helper_invalidate (self);
    }
}

static void
gtk_icon_helper_finalize (GObject *object)
{
  GtkIconHelper *self = GTK_ICON_HELPER (object);

  _gtk_icon_helper_clear (self);
  g_signal_handlers_disconnect_by_func (self->owner, G_CALLBACK (gtk_icon_helper_invalidate), self);
  gtk_image_definition_unref (self->def);

  G_OBJECT_CLASS (gtk_icon_helper_parent_class)->finalize (object);
}

void
gtk_icon_helper_class_init (GtkIconHelperClass *klass)
{
  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);

  gobject_class->finalize = gtk_icon_helper_finalize;
}

void
gtk_icon_helper_init (GtkIconHelper *self)
{
  self->def = gtk_image_definition_new_empty ();
}

GtkIconHelper *
gtk_icon_helper_new (GtkCssNode *css_node,
                     GtkWidget  *owner)
{
  GtkIconHelper *self;
  
  self = g_object_new (GTK_TYPE_ICON_HELPER, NULL);

  self->pixel_size = -1;
  self->texture_is_symbolic = FALSE;

  self->node = css_node;
  self->owner = owner;
  g_signal_connect_swapped (owner, "direction-changed", G_CALLBACK (gtk_icon_helper_invalidate), self);
  g_signal_connect_swapped (owner, "notify::scale-factor", G_CALLBACK (gtk_icon_helper_invalidate), self);

  return self;
}

GtkSizeRequestMode
gtk_icon_helper_get_request_mode (GtkIconHelper *self)
{
  switch (gtk_image_definition_get_storage_type (self->def))
    {
    case GTK_IMAGE_PAINTABLE:
      return GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH;

    case GTK_IMAGE_ICON_NAME:
    case GTK_IMAGE_GICON:
    case GTK_IMAGE_EMPTY:
    default:
      return GTK_SIZE_REQUEST_CONSTANT_SIZE;
    }
}

void
gtk_icon_helper_measure (GtkIconHelper *self,
                         GtkOrientation orientation,
                         int            for_size,
                         int           *minimum,
                         int           *natural)
{
  switch (gtk_image_definition_get_storage_type (self->def))
    {
    case GTK_IMAGE_PAINTABLE:
      {
        double min_width, min_height, nat_width, nat_height;
        int default_size = get_default_size (self);

        gdk_paintable_compute_concrete_size (gtk_image_definition_get_paintable (self->def),
                                             0, 0,
                                             default_size, default_size,
                                             &min_width, &min_height);

        if (orientation == GTK_ORIENTATION_HORIZONTAL)
          {
            gdk_paintable_compute_concrete_size (gtk_image_definition_get_paintable (self->def),
                                                 0,
                                                 for_size < 0 ? 0 : for_size,
                                                 default_size, default_size,
                                                 &nat_width, &nat_height);
            *minimum = ceil (min_width);
            *natural = ceil (nat_width);
          }
        else
          {
            gdk_paintable_compute_concrete_size (gtk_image_definition_get_paintable (self->def),
                                                 for_size < 0 ? 0 : for_size,
                                                 0,
                                                 default_size, default_size,
                                                 &nat_width, &nat_height);
            *minimum = ceil (min_height);
            *natural = ceil (nat_height);
          }
      }
      break;

    case GTK_IMAGE_ICON_NAME:
    case GTK_IMAGE_GICON:
    case GTK_IMAGE_EMPTY:
    default:
      {
        int width, height;

        _gtk_icon_helper_get_size (self, &width, &height);
        if (orientation == GTK_ORIENTATION_HORIZONTAL)
          *minimum = *natural = width;
        else
          *minimum = *natural = height;
      }
      break;
    }
}

static void
get_size_for_paintable (GtkIconHelper *self,
                        GdkPaintable  *paintable,
                        int           *width_out,
                        int           *height_out)
{
  int width = gdk_paintable_get_intrinsic_width (paintable);
  int height = gdk_paintable_get_intrinsic_height (paintable);

  if (width == 0)
    {
      if (height != 0)
        {
          double ar = gdk_paintable_get_intrinsic_aspect_ratio (paintable);

          if (ar > 0)
            width = ceil (height * ar);
        }
    }
  else
    {
      if (height == 0)
        {
          double ar = gdk_paintable_get_intrinsic_aspect_ratio (paintable);

          if (ar > 0)
            height = ceil (width / ar);
        }
    }
  
  if (width == 0 || height == 0)
    width = height = get_default_size (self);

  *width_out = width;
  *height_out = height;
}

void
_gtk_icon_helper_get_size (GtkIconHelper *self,
                           gint *width_out,
                           gint *height_out)
{
  gint width, height;

  width = height = 0;

  /* Certain kinds of images are easy to calculate the size for, these
     we do immediately to avoid having to potentially load the image
     data for something that may not yet be visible */
  switch (gtk_image_definition_get_storage_type (self->def))
    {
    case GTK_IMAGE_ICON_NAME:
    case GTK_IMAGE_GICON:
      if (self->pixel_size != -1 || self->force_scale_pixbuf)
        width = height = get_default_size (self);
      break;

    case GTK_IMAGE_PAINTABLE:
      {
        GdkPaintable *paintable = gtk_image_definition_get_paintable (self->def);

        get_size_for_paintable (self, paintable, &width, &height);
      }
      break;

    case GTK_IMAGE_EMPTY:
    default:
      break;
    }

  /* Otherwise we load the paintable to guarantee we get a size */
  if (width == 0)
    {
      gtk_icon_helper_ensure_paintable (self);

      if (self->paintable != NULL)
        {
          get_size_for_paintable (self, self->paintable, &width, &height);
        }
      else
        {
          width = height = get_default_size (self);
        }
    }

  if (width_out)
    *width_out = width;
  if (height_out)
    *height_out = height;
}

void
_gtk_icon_helper_set_definition (GtkIconHelper *self,
                                 GtkImageDefinition *def)
{
  if (def)
    gtk_icon_helper_take_definition (self, gtk_image_definition_ref (def));
  else
    _gtk_icon_helper_clear (self);
}

void
_gtk_icon_helper_set_gicon (GtkIconHelper *self,
                            GIcon         *gicon)
{
  gtk_icon_helper_take_definition (self, gtk_image_definition_new_gicon (gicon));
}

void
_gtk_icon_helper_set_icon_name (GtkIconHelper *self,
                                const gchar   *icon_name)
{
  gtk_icon_helper_take_definition (self, gtk_image_definition_new_icon_name (icon_name));
}

void
_gtk_icon_helper_set_paintable (GtkIconHelper *self,
			        GdkPaintable  *paintable)
{
  gtk_icon_helper_take_definition (self, gtk_image_definition_new_paintable (paintable));
}

gboolean
_gtk_icon_helper_set_pixel_size (GtkIconHelper *self,
                                 gint           pixel_size)
{
  if (self->pixel_size != pixel_size)
    {
      self->pixel_size = pixel_size;
      gtk_icon_helper_invalidate (self);
      return TRUE;
    }
  return FALSE;
}

gboolean
_gtk_icon_helper_set_use_fallback (GtkIconHelper *self,
                                   gboolean       use_fallback)
{
  if (self->use_fallback != use_fallback)
    {
      self->use_fallback = use_fallback;
      gtk_icon_helper_invalidate (self);
      return TRUE;
    }
  return FALSE;
}

GtkImageType
_gtk_icon_helper_get_storage_type (GtkIconHelper *self)
{
  return gtk_image_definition_get_storage_type (self->def);
}

gboolean
_gtk_icon_helper_get_use_fallback (GtkIconHelper *self)
{
  return self->use_fallback;
}

gint
_gtk_icon_helper_get_pixel_size (GtkIconHelper *self)
{
  return self->pixel_size;
}

GtkImageDefinition *
gtk_icon_helper_get_definition (GtkIconHelper *self)
{
  return self->def;
}

GIcon *
_gtk_icon_helper_peek_gicon (GtkIconHelper *self)
{
  return gtk_image_definition_get_gicon (self->def);
}

GdkPaintable *
_gtk_icon_helper_peek_paintable (GtkIconHelper *self)
{
  return gtk_image_definition_get_paintable (self->def);
}

const gchar *
_gtk_icon_helper_get_icon_name (GtkIconHelper *self)
{
  return gtk_image_definition_get_icon_name (self->def);
}

gboolean
_gtk_icon_helper_get_is_empty (GtkIconHelper *self)
{
  return gtk_image_definition_get_storage_type (self->def) == GTK_IMAGE_EMPTY;
}

gboolean
_gtk_icon_helper_get_force_scale_pixbuf (GtkIconHelper *self)
{
  return self->force_scale_pixbuf;
}

void
_gtk_icon_helper_set_force_scale_pixbuf (GtkIconHelper *self,
                                         gboolean       force_scale)
{
  if (self->force_scale_pixbuf != force_scale)
    {
      self->force_scale_pixbuf = force_scale;
      gtk_icon_helper_invalidate (self);
    }
}

void
gtk_icon_size_set_style_classes (GtkCssNode  *cssnode,
                                 GtkIconSize  icon_size)
{
  struct {
    GtkIconSize icon_size;
    const char *class_name;
  } class_names[] = {
    { GTK_ICON_SIZE_NORMAL, "normal-icons" },
    { GTK_ICON_SIZE_LARGE, "large-icons" }
  };
  guint i;

  for (i = 0; i < G_N_ELEMENTS (class_names); i++)
    {
      if (icon_size == class_names[i].icon_size)
        gtk_css_node_add_class (cssnode, g_quark_from_static_string (class_names[i].class_name));
      else
        gtk_css_node_remove_class (cssnode, g_quark_from_static_string (class_names[i].class_name));
    }
}