glade/gladeui/glade-placeholder.c

/*
 * Copyright (C) 2003, 2004 Joaquin Cuenca Abela
 *
 * Authors:
 *   Joaquin Cuenca Abela <e98cuenc@yahoo.com> 
 * 
 * This program 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; either version 2 of the
 * License, or (at your option) any later version.
 *
 * 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 General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
*/

#include "config.h"

/**
 * SECTION:glade-placeholder
 * @Short_Description: A #GtkWidget to fill empty places.
 *
 * Generally in Glade, container widgets are implemented with #GladePlaceholder 
 * children to allow users to 'click' and add thier widgets to a container. 
 * It is the responsability of the plugin writer to create placeholders for 
 * container widgets where appropriate; usually in #GladePostCreateFunc 
 * when the #GladeCreateReason is %GLADE_CREATE_USER.
 */

#include <gtk/gtk.h>
#include "glade-marshallers.h"
#include "glade.h"
#include "glade-placeholder.h"
#include "glade-xml-utils.h"
#include "glade-project.h"
#include "glade-command.h"
#include "glade-palette.h"
#include "glade-popup.h"
#include "glade-cursor.h"
#include "glade-widget.h"
#include "glade-app.h"
#include <math.h>

#define WIDTH_REQUISITION    20
#define HEIGHT_REQUISITION   20

static void glade_placeholder_finalize (GObject *object);
static void glade_placeholder_set_property (GObject *object,
                                            guint prop_id,
                                            const GValue *value,
                                            GParamSpec *pspec);
static void glade_placeholder_get_property (GObject *object,
                                            guint prop_id,
                                            GValue *value,
                                            GParamSpec *pspec);
static void glade_placeholder_realize (GtkWidget *widget);
static void glade_placeholder_unrealize (GtkWidget *widget);
static void glade_placeholder_map (GtkWidget *widget);
static void glade_placeholder_unmap (GtkWidget *widget);

static void glade_placeholder_size_allocate (GtkWidget *widget,
                                             GtkAllocation *allocation);

static gboolean glade_placeholder_draw (GtkWidget *widget, cairo_t *cr);

static gboolean glade_placeholder_motion_notify_event (GtkWidget *widget,
                                                       GdkEventMotion *event);

static gboolean glade_placeholder_button_press (GtkWidget *widget,
                                                GdkEventButton *event);

static gboolean glade_placeholder_popup_menu (GtkWidget *widget);


static cairo_pattern_t *placeholder_pattern = NULL;

struct _GladePlaceholderPrivate
{
  GList *packing_actions;

  GdkWindow *event_window;
};

enum
{
  PROP_0,
  PROP_HADJUSTMENT,
  PROP_VADJUSTMENT,
  PROP_HSCROLL_POLICY,
  PROP_VSCROLL_POLICY
};

#define GLADE_PLACEHOLDER_GET_PRIVATE(object) (G_TYPE_INSTANCE_GET_PRIVATE ((object), \
                                               GLADE_TYPE_PLACEHOLDER,                \
                                               GladePlaceholderPrivate))

G_DEFINE_TYPE_WITH_CODE (GladePlaceholder, glade_placeholder, GTK_TYPE_WIDGET,
                         G_IMPLEMENT_INTERFACE (GTK_TYPE_SCROLLABLE, NULL))

static void glade_placeholder_class_init (GladePlaceholderClass *klass)
{
  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
  GObjectClass *object_class = G_OBJECT_CLASS (klass);
  gchar *path;
  cairo_surface_t *surface;

  object_class->finalize = glade_placeholder_finalize;
  object_class->set_property = glade_placeholder_set_property;
  object_class->get_property = glade_placeholder_get_property;

  widget_class->realize = glade_placeholder_realize;
  widget_class->unrealize = glade_placeholder_unrealize;
  widget_class->map = glade_placeholder_map;
  widget_class->unmap = glade_placeholder_unmap;
  widget_class->size_allocate = glade_placeholder_size_allocate;
  widget_class->draw = glade_placeholder_draw;
  widget_class->motion_notify_event = glade_placeholder_motion_notify_event;
  widget_class->button_press_event = glade_placeholder_button_press;
  widget_class->popup_menu = glade_placeholder_popup_menu;

  /* GtkScrollable implementation */
  g_object_class_override_property (object_class, PROP_HADJUSTMENT,
                                    "hadjustment");
  g_object_class_override_property (object_class, PROP_VADJUSTMENT,
                                    "vadjustment");
  g_object_class_override_property (object_class, PROP_HSCROLL_POLICY,
                                    "hscroll-policy");
  g_object_class_override_property (object_class, PROP_VSCROLL_POLICY,
                                    "vscroll-policy");

  /* Create our tiled background pattern */
  path = g_build_filename (glade_app_get_pixmaps_dir (), "placeholder.png", NULL);
  surface = cairo_image_surface_create_from_png (path);

  if (!surface)
    g_warning ("Failed to create surface for %s\n", path);
  else
    {
      placeholder_pattern = cairo_pattern_create_for_surface (surface);
      cairo_pattern_set_extend (placeholder_pattern, CAIRO_EXTEND_REPEAT);
    }
  g_free (path);

  g_type_class_add_private (klass, sizeof (GladePlaceholderPrivate));
}

static void
glade_placeholder_notify_parent (GObject *gobject,
                                 GParamSpec *arg1,
                                 gpointer user_data)
{
  GladePlaceholder *placeholder = GLADE_PLACEHOLDER (gobject);
  GladeWidgetAdaptor *parent_adaptor = NULL;
  GladeWidget *parent = glade_placeholder_get_parent (placeholder);

  if (placeholder->priv->packing_actions)
    {
      g_list_foreach (placeholder->priv->packing_actions, (GFunc) g_object_unref,
                      NULL);
      g_list_free (placeholder->priv->packing_actions);
      placeholder->priv->packing_actions = NULL;
    }

  if (parent)
    parent_adaptor = glade_widget_get_adaptor (parent);

  if (parent_adaptor)
    placeholder->priv->packing_actions =
      glade_widget_adaptor_pack_actions_new (parent_adaptor);
}

static void
glade_placeholder_init (GladePlaceholder *placeholder)
{
  placeholder->priv =  GLADE_PLACEHOLDER_GET_PRIVATE (placeholder);

  placeholder->priv->packing_actions = NULL;

  gtk_widget_set_can_focus (GTK_WIDGET (placeholder), TRUE);
  gtk_widget_set_has_window (GTK_WIDGET (placeholder), FALSE);

  gtk_widget_set_size_request (GTK_WIDGET (placeholder),
                               WIDTH_REQUISITION, HEIGHT_REQUISITION);

  g_signal_connect (placeholder, "notify::parent",
                    G_CALLBACK (glade_placeholder_notify_parent), NULL);

  gtk_widget_set_hexpand (GTK_WIDGET (placeholder), TRUE);
  gtk_widget_set_vexpand (GTK_WIDGET (placeholder), TRUE);
  gtk_widget_show (GTK_WIDGET (placeholder));
}

static void
glade_placeholder_finalize (GObject *object)
{
  GladePlaceholder *placeholder;

  g_return_if_fail (GLADE_IS_PLACEHOLDER (object));
  placeholder = GLADE_PLACEHOLDER (object);

  if (placeholder->priv->packing_actions)
    {
      g_list_foreach (placeholder->priv->packing_actions, (GFunc) g_object_unref, NULL);
      g_list_free (placeholder->priv->packing_actions);
    }

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

static void
glade_placeholder_set_property (GObject *object,
                                guint prop_id,
                                const GValue *value,
                                GParamSpec *pspec)
{

  switch (prop_id)
    {
      case PROP_HADJUSTMENT:
      case PROP_VADJUSTMENT:
      case PROP_HSCROLL_POLICY:
      case PROP_VSCROLL_POLICY:
        break;
      default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
        break;
    }
}

static void
glade_placeholder_get_property (GObject *object,
                                guint prop_id,
                                GValue *value,
                                GParamSpec *pspec)
{
  switch (prop_id)
    {
      case PROP_HADJUSTMENT:
      case PROP_VADJUSTMENT:
        g_value_set_object (value, NULL);
        break;
      case PROP_HSCROLL_POLICY:
      case PROP_VSCROLL_POLICY:
        g_value_set_enum (value, GTK_SCROLL_MINIMUM);
        break;
      default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
        break;
    }
}

static void
glade_placeholder_realize (GtkWidget *widget)
{
  GladePlaceholder *placeholder;
  GtkAllocation allocation;
  GdkWindow *window;
  GdkWindowAttr attributes;
  gint attributes_mask;

  placeholder = GLADE_PLACEHOLDER (widget);

  gtk_widget_set_realized (widget, TRUE);

  gtk_widget_get_allocation (widget, &allocation);
  attributes.x = allocation.x;
  attributes.y = allocation.y;
  attributes.width = allocation.width;
  attributes.height = allocation.height;

  attributes.window_type = GDK_WINDOW_CHILD;
  attributes.wclass = GDK_INPUT_ONLY;
  attributes.event_mask =
      gtk_widget_get_events (widget) |
      GDK_POINTER_MOTION_MASK |
      GDK_POINTER_MOTION_HINT_MASK |
      GDK_BUTTON_PRESS_MASK |
      GDK_BUTTON_RELEASE_MASK | GDK_ENTER_NOTIFY_MASK | GDK_LEAVE_NOTIFY_MASK;
  attributes_mask = GDK_WA_X | GDK_WA_Y;

  window = gtk_widget_get_parent_window (widget);
  gtk_widget_set_window (widget, g_object_ref (window));

  placeholder->priv->event_window =
      gdk_window_new (gtk_widget_get_parent_window (widget), &attributes,
                      attributes_mask);
  gdk_window_set_user_data (placeholder->priv->event_window, widget);

  gtk_widget_style_attach (widget);
}

static void
glade_placeholder_unrealize (GtkWidget *widget)
{
  GladePlaceholder *placeholder;

  placeholder = GLADE_PLACEHOLDER (widget);

  if (placeholder->priv->event_window)
    {
      gdk_window_set_user_data (placeholder->priv->event_window, NULL);
      gdk_window_destroy (placeholder->priv->event_window);
      placeholder->priv->event_window = NULL;
    }

  GTK_WIDGET_CLASS (glade_placeholder_parent_class)->unrealize (widget);
}

static void
glade_placeholder_map (GtkWidget *widget)
{
  GladePlaceholder *placeholder;

  placeholder = GLADE_PLACEHOLDER (widget);

  if (placeholder->priv->event_window)
    {
      gdk_window_show (placeholder->priv->event_window);
    }

  GTK_WIDGET_CLASS (glade_placeholder_parent_class)->map (widget);
}

static void
glade_placeholder_unmap (GtkWidget *widget)
{
  GladePlaceholder *placeholder;

  placeholder = GLADE_PLACEHOLDER (widget);

  if (placeholder->priv->event_window)
    {
      gdk_window_hide (placeholder->priv->event_window);
    }

  GTK_WIDGET_CLASS (glade_placeholder_parent_class)->unmap (widget);
}

static void
glade_placeholder_size_allocate (GtkWidget *widget, GtkAllocation *allocation)
{
  GladePlaceholder *placeholder;

  placeholder = GLADE_PLACEHOLDER (widget);

  gtk_widget_set_allocation (widget, allocation);

  if (gtk_widget_get_realized (widget))
    {
      gdk_window_move_resize (placeholder->priv->event_window,
                              allocation->x, allocation->y,
                              allocation->width, allocation->height);
    }
}

static gboolean
glade_placeholder_draw (GtkWidget *widget, cairo_t *cr)
{
  GtkStyle *style;
  GdkColor *light;
  GdkColor *dark;
  gint w, h;

  style = gtk_widget_get_style (widget);
  light = &style->light[GTK_STATE_NORMAL];
  dark = &style->dark[GTK_STATE_NORMAL];

  h = gtk_widget_get_allocated_height (widget);
  w = gtk_widget_get_allocated_width (widget);

  if (placeholder_pattern)
    {
      cairo_save (cr);
      cairo_rectangle (cr, 0, 0, w, h);
      cairo_set_source (cr, placeholder_pattern);
      cairo_fill (cr);
      cairo_restore (cr);
    }

  cairo_set_line_width (cr, 1.0);

  glade_utils_cairo_draw_line (cr, light, 0, 0, w - 1, 0);
  glade_utils_cairo_draw_line (cr, light, 0, 0, 0, h - 1);
  glade_utils_cairo_draw_line (cr, dark, 0, h - 1, w - 1, h - 1);
  glade_utils_cairo_draw_line (cr, dark, w - 1, 0, w - 1, h - 1);

  return FALSE;
}

static gboolean
glade_placeholder_motion_notify_event (GtkWidget *widget, GdkEventMotion *event)
{
  GladePointerMode pointer_mode;
  GladeProject *project;

  g_return_val_if_fail (GLADE_IS_PLACEHOLDER (widget), FALSE);

  project      = glade_placeholder_get_project (GLADE_PLACEHOLDER (widget));
  pointer_mode = glade_project_get_pointer_mode (project);

  if (pointer_mode == GLADE_POINTER_SELECT)
    glade_cursor_set (project, event->window, GLADE_CURSOR_SELECTOR);
  else if (pointer_mode == GLADE_POINTER_ADD_WIDGET)
    glade_cursor_set (project, event->window, GLADE_CURSOR_ADD_WIDGET);

  return FALSE;
}

static gboolean
glade_placeholder_button_press (GtkWidget *widget, GdkEventButton *event)
{
  GladePlaceholder   *placeholder;
  GladeProject       *project;
  GladeWidgetAdaptor *adaptor;
  gboolean            handled = FALSE;

  g_return_val_if_fail (GLADE_IS_PLACEHOLDER (widget), FALSE);

  placeholder = GLADE_PLACEHOLDER (widget);
  project     = glade_placeholder_get_project (placeholder);
  adaptor     = glade_project_get_add_item (project);

  if (!gtk_widget_has_focus (widget))
    gtk_widget_grab_focus (widget);

  if (event->button == 1 && event->type == GDK_BUTTON_PRESS)
    {
      if (adaptor != NULL)
        {
          GladeWidget *parent = glade_placeholder_get_parent (placeholder);

          if (!glade_util_check_and_warn_scrollable
              (parent, adaptor, glade_app_get_window ()))
            {
              /* A widget type is selected in the palette.
               * Add a new widget of that type.
               */
              glade_command_create (adaptor, parent, placeholder, project);

	      glade_project_set_add_item (project, NULL);

              /* reset the cursor */
              glade_cursor_set (project, event->window, GLADE_CURSOR_SELECTOR);
            }
          handled = TRUE;
        }
    }

  if (!handled && glade_popup_is_popup_event (event))
    {
      glade_popup_placeholder_pop (placeholder, event);
      handled = TRUE;
    }

  return handled;
}

static gboolean
glade_placeholder_popup_menu (GtkWidget *widget)
{
  g_return_val_if_fail (GLADE_IS_PLACEHOLDER (widget), FALSE);

  glade_popup_placeholder_pop (GLADE_PLACEHOLDER (widget), NULL);

  return TRUE;
}


/**
 * glade_placeholder_new:
 * 
 * Returns: a new #GladePlaceholder cast as a #GtkWidget
 */
GtkWidget *
glade_placeholder_new (void)
{
  return g_object_new (GLADE_TYPE_PLACEHOLDER, NULL);
}

GladeProject *
glade_placeholder_get_project (GladePlaceholder *placeholder)
{
  GladeWidget *parent;
  parent = glade_placeholder_get_parent (placeholder);
  return parent ? glade_widget_get_project (parent) : NULL;
}

GladeWidget *
glade_placeholder_get_parent (GladePlaceholder *placeholder)
{
  GtkWidget *widget;
  GladeWidget *parent = NULL;

  g_return_val_if_fail (GLADE_IS_PLACEHOLDER (placeholder), NULL);

  for (widget = gtk_widget_get_parent (GTK_WIDGET (placeholder));
       widget != NULL; widget = gtk_widget_get_parent (widget))
    {
      if ((parent = glade_widget_get_from_gobject (widget)) != NULL)
        break;
    }
  return parent;
}

GList *
glade_placeholder_packing_actions (GladePlaceholder *placeholder)
{
  g_return_val_if_fail (GLADE_IS_PLACEHOLDER (placeholder), NULL);

  return placeholder->priv->packing_actions;
}