/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 8; tab-width: 8 -*- */

/* peony-clipboard.c
 *
 * Peony Clipboard support.  For now, routines to support component cut
 * and paste.
 *
 * Copyright (C) 1999, 2000  Free Software Foundaton
 * Copyright (C) 2000, 2001  Eazel, Inc.
 *
 * This program 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.
 *
 * 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 * Authors: Rebecca Schulman <rebecka@eazel.com>,
 *          Darin Adler <darin@bentspoon.com>
 */

#include <config.h>
#include "peony-clipboard.h"
#include "peony-file-utilities.h"

#include <glib/gi18n.h>
#include <gtk/gtk.h>
#include <string.h>

typedef struct _TargetCallbackData TargetCallbackData;

typedef void (* SelectAllCallback)    (gpointer target);
typedef void (* ConnectCallbacksFunc) (GObject            *object,
                                       TargetCallbackData *target_data);

static void selection_changed_callback            (GtkWidget *widget,
        gpointer callback_data);
static void owner_change_callback (GtkClipboard        *clipboard,
                                   GdkEventOwnerChange *event,
                                   gpointer callback_data);
struct _TargetCallbackData
{
    GtkUIManager *ui_manager;
    GtkActionGroup *action_group;
    gboolean shares_selection_changes;

    SelectAllCallback select_all_callback;

    ConnectCallbacksFunc connect_callbacks;
    ConnectCallbacksFunc disconnect_callbacks;
};

static void
cut_callback (gpointer target)
{
    g_assert (target != NULL);

    g_signal_emit_by_name (target, "cut-clipboard");
}

static void
copy_callback (gpointer target)
{
    g_assert (target != NULL);

    g_signal_emit_by_name (target, "copy-clipboard");
}

static void
paste_callback (gpointer target)
{
    g_assert (target != NULL);

    g_signal_emit_by_name (target, "paste-clipboard");
}

static void
editable_select_all_callback (gpointer target)
{
    GtkEditable *editable;

    editable = GTK_EDITABLE (target);
    g_assert (editable != NULL);

    gtk_editable_set_position (editable, -1);
    gtk_editable_select_region (editable, 0, -1);
}

static void
text_view_select_all_callback (gpointer target)
{
    g_assert (GTK_IS_TEXT_VIEW (target));

    g_signal_emit_by_name (target, "select-all", TRUE);
}

static void
action_cut_callback (GtkAction *action,
                     gpointer callback_data)
{
    cut_callback (callback_data);
}

static void
action_copy_callback (GtkAction *action,
                      gpointer callback_data)
{
    copy_callback (callback_data);
}

static void
action_paste_callback (GtkAction *action,
                       gpointer callback_data)
{
    paste_callback (callback_data);
}

static void
action_select_all_callback (GtkAction *action,
                            gpointer callback_data)
{
    TargetCallbackData *target_data;

    g_assert (callback_data != NULL);

    target_data = g_object_get_data (callback_data, "Peony:clipboard_target_data");
    g_assert (target_data != NULL);

    target_data->select_all_callback (callback_data);
}

static void
received_clipboard_contents (GtkClipboard     *clipboard,
                             GtkSelectionData *selection_data,
                             gpointer          data)
{
    GtkActionGroup *action_group;
    GtkAction *action;

    action_group = data;

    action = gtk_action_group_get_action (action_group,
                                          "Paste");
    if (action != NULL)
    {
        gtk_action_set_sensitive (action,
                                  gtk_selection_data_targets_include_text (selection_data));
    }

    g_object_unref (action_group);
}


static void
set_paste_sensitive_if_clipboard_contains_data (GtkActionGroup *action_group)
{
    GtkAction *action;
    if (gdk_display_supports_selection_notification (gdk_display_get_default ()))
    {
        gtk_clipboard_request_contents (gtk_clipboard_get (GDK_SELECTION_CLIPBOARD),
                                        gdk_atom_intern ("TARGETS", FALSE),
                                        received_clipboard_contents,
                                        g_object_ref (action_group));
    }
    else
    {
        /* If selection notification isn't supported, always activate Paste */
        action = gtk_action_group_get_action (action_group,
                                              "Paste");
        gtk_action_set_sensitive (action, TRUE);
    }
}

static void
set_clipboard_menu_items_sensitive (GtkActionGroup *action_group)
{
    GtkAction *action;

    action = gtk_action_group_get_action (action_group,
                                          "Cut");
    gtk_action_set_sensitive (action, TRUE);
    action = gtk_action_group_get_action (action_group,
                                          "Copy");
    gtk_action_set_sensitive (action, TRUE);
}

static void
set_clipboard_menu_items_insensitive (GtkActionGroup *action_group)
{
    GtkAction *action;

    action = gtk_action_group_get_action (action_group,
                                          "Cut");
    gtk_action_set_sensitive (action, FALSE);
    action = gtk_action_group_get_action (action_group,
                                          "Copy");
    gtk_action_set_sensitive (action, FALSE);
}

static gboolean
clipboard_items_are_merged_in (GtkWidget *widget)
{
    return GPOINTER_TO_INT (g_object_get_data (G_OBJECT (widget),
                            "Peony:clipboard_menu_items_merged"));
}

static void
set_clipboard_items_are_merged_in (GObject *widget_as_object,
                                   gboolean merged_in)
{
    g_object_set_data (widget_as_object,
                       "Peony:clipboard_menu_items_merged",
                       GINT_TO_POINTER (merged_in));
}

static void
editable_connect_callbacks (GObject *object,
                            TargetCallbackData *target_data)
{
    g_signal_connect_after (object, "selection_changed",
                            G_CALLBACK (selection_changed_callback), target_data);
    selection_changed_callback (GTK_WIDGET (object),
                                target_data);
}

static void
editable_disconnect_callbacks (GObject *object,
                               TargetCallbackData *target_data)
{
    g_signal_handlers_disconnect_matched (object,
                                          G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA,
                                          0, 0, NULL,
                                          G_CALLBACK (selection_changed_callback),
                                          target_data);
}

static void
text_buffer_update_sensitivity (GtkTextBuffer *buffer,
                                TargetCallbackData *target_data)
{
    g_assert (GTK_IS_TEXT_BUFFER (buffer));
    g_assert (target_data != NULL);

    if (gtk_text_buffer_get_selection_bounds (buffer, NULL, NULL))
    {
        set_clipboard_menu_items_sensitive (target_data->action_group);
    }
    else
    {
        set_clipboard_menu_items_insensitive (target_data->action_group);
    }
}

static void
text_buffer_delete_range (GtkTextBuffer *buffer,
                          GtkTextIter   *iter1,
                          GtkTextIter   *iter2,
                          TargetCallbackData *target_data)
{
    text_buffer_update_sensitivity (buffer, target_data);
}

static void
text_buffer_mark_set (GtkTextBuffer *buffer,
                      GtkTextIter *iter,
                      GtkTextMark *mark,
                      TargetCallbackData *target_data)
{
    /* anonymous marks with NULL names refer to cursor moves */
    if (gtk_text_mark_get_name (mark) != NULL)
    {
        text_buffer_update_sensitivity (buffer, target_data);
    }
}

static void
text_view_connect_callbacks (GObject *object,
                             TargetCallbackData *target_data)
{
    GtkTextBuffer *buffer;

    buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (object));
    g_assert (buffer);

    g_signal_connect_after (buffer, "mark-set",
                            G_CALLBACK (text_buffer_mark_set), target_data);
    g_signal_connect_after (buffer, "delete-range",
                            G_CALLBACK (text_buffer_delete_range), target_data);
    text_buffer_update_sensitivity (buffer, target_data);
}

static void
text_view_disconnect_callbacks (GObject *object,
                                TargetCallbackData *target_data)
{
    GtkTextBuffer *buffer;

    buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (object));
    g_assert (buffer);

    g_signal_handlers_disconnect_matched (buffer,
                                          G_SIGNAL_MATCH_DATA,
                                          0, 0, NULL, NULL,
                                          target_data);
}

static void
merge_in_clipboard_menu_items (GObject *widget_as_object,
                               TargetCallbackData *target_data)
{
    gboolean add_selection_callback;

    g_assert (target_data != NULL);

    add_selection_callback = target_data->shares_selection_changes;

    gtk_ui_manager_insert_action_group (target_data->ui_manager,
                                        target_data->action_group, 0);

    set_paste_sensitive_if_clipboard_contains_data (target_data->action_group);

    g_signal_connect (gtk_clipboard_get (GDK_SELECTION_CLIPBOARD), "owner_change",
                      G_CALLBACK (owner_change_callback), target_data);

    if (add_selection_callback)
    {
        target_data->connect_callbacks (widget_as_object, target_data);
    }
    else
    {
        /* If we don't use sensitivity, everything should be on */
        set_clipboard_menu_items_sensitive (target_data->action_group);
    }
    set_clipboard_items_are_merged_in (widget_as_object, TRUE);
}

static void
merge_out_clipboard_menu_items (GObject *widget_as_object,
                                TargetCallbackData *target_data)

{
    gboolean selection_callback_was_added;

    g_assert (target_data != NULL);

    gtk_ui_manager_remove_action_group (target_data->ui_manager,
                                        target_data->action_group);

    g_signal_handlers_disconnect_matched (gtk_clipboard_get (GDK_SELECTION_CLIPBOARD),
                                          G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA,
                                          0, 0, NULL,
                                          G_CALLBACK (owner_change_callback),
                                          target_data);

    selection_callback_was_added = target_data->shares_selection_changes;

    if (selection_callback_was_added)
    {
        target_data->disconnect_callbacks (widget_as_object, target_data);
    }
    set_clipboard_items_are_merged_in (widget_as_object, FALSE);
}

static gboolean
focus_changed_callback (GtkWidget *widget,
                        GdkEventAny *event,
                        gpointer callback_data)
{
    /* Connect the component to the container if the widget has focus. */
    if (gtk_widget_has_focus (widget))
    {
        if (!clipboard_items_are_merged_in (widget))
        {
            merge_in_clipboard_menu_items (G_OBJECT (widget), callback_data);
        }
    }
    else
    {
        if (clipboard_items_are_merged_in (widget))
        {
            merge_out_clipboard_menu_items (G_OBJECT (widget), callback_data);
        }
    }

    return FALSE;
}

static void
selection_changed_callback (GtkWidget *widget,
                            gpointer callback_data)
{
    TargetCallbackData *target_data;
    GtkEditable *editable;
    int start, end;

    target_data = (TargetCallbackData *) callback_data;
    g_assert (target_data != NULL);

    editable = GTK_EDITABLE (widget);
    g_assert (editable != NULL);

    if (gtk_editable_get_selection_bounds (editable, &start, &end) && start != end)
    {
        set_clipboard_menu_items_sensitive (target_data->action_group);
    }
    else
    {
        set_clipboard_menu_items_insensitive (target_data->action_group);
    }
}

static void
owner_change_callback (GtkClipboard        *clipboard,
                       GdkEventOwnerChange *event,
                       gpointer callback_data)
{
    TargetCallbackData *target_data;

    g_assert (callback_data != NULL);
    target_data = callback_data;

    set_paste_sensitive_if_clipboard_contains_data (target_data->action_group);
}

static void
target_destroy_callback (GtkWidget *object,
                         gpointer callback_data)
{
    g_assert (callback_data != NULL);

    if (clipboard_items_are_merged_in (object))
    {
        merge_out_clipboard_menu_items (G_OBJECT (object), callback_data);
    }
}

static void
target_data_free (TargetCallbackData *target_data)
{
    g_object_unref (target_data->action_group);
    g_free (target_data);
}

static const GtkActionEntry clipboard_entries[] =
{
    /* name, stock id */      { "Cut", GTK_STOCK_CUT,
        /* label, accelerator */    NULL, NULL,
        /* tooltip */               N_("Cut the selected text to the clipboard"),
        G_CALLBACK (action_cut_callback)
    },
    /* name, stock id */      { "Copy", GTK_STOCK_COPY,
        /* label, accelerator */    NULL, NULL,
        /* tooltip */               N_("Copy the selected text to the clipboard"),
        G_CALLBACK (action_copy_callback)
    },
    /* name, stock id */      { "Paste", GTK_STOCK_PASTE,
        /* label, accelerator */    NULL, NULL,
        /* tooltip */               N_("Paste the text stored on the clipboard"),
        G_CALLBACK (action_paste_callback)
    },
    /* name, stock id */      { "Select All", NULL,
        /* label, accelerator */    N_("Select _All"), "<control>A",
        /* tooltip */               N_("Select all the text in a text field"),
        G_CALLBACK (action_select_all_callback)
    },
};

static TargetCallbackData *
initialize_clipboard_component_with_callback_data (GtkEditable *target,
        GtkUIManager *ui_manager,
        gboolean shares_selection_changes,
        SelectAllCallback select_all_callback,
        ConnectCallbacksFunc connect_callbacks,
        ConnectCallbacksFunc disconnect_callbacks)
{
    GtkActionGroup *action_group;
    TargetCallbackData *target_data;

    action_group = gtk_action_group_new ("ClipboardActions");
    gtk_action_group_set_translation_domain (action_group, GETTEXT_PACKAGE);
    gtk_action_group_add_actions (action_group,
                                  clipboard_entries, G_N_ELEMENTS (clipboard_entries),
                                  target);

    /* Do the actual connection of the UI to the container at
     * focus time, and disconnect at both focus and destroy
     * time.
     */
    target_data = g_new (TargetCallbackData, 1);
    target_data->ui_manager = ui_manager;
    target_data->action_group = action_group;
    target_data->shares_selection_changes = shares_selection_changes;
    target_data->select_all_callback = select_all_callback;
    target_data->connect_callbacks = connect_callbacks;
    target_data->disconnect_callbacks = disconnect_callbacks;

    return target_data;
}

static void
peony_clipboard_real_set_up (gpointer target,
                            GtkUIManager *ui_manager,
                            gboolean shares_selection_changes,
                            SelectAllCallback select_all_callback,
                            ConnectCallbacksFunc connect_callbacks,
                            ConnectCallbacksFunc disconnect_callbacks)
{
    TargetCallbackData *target_data;

    if (g_object_get_data (G_OBJECT (target), "Peony:clipboard_target_data") != NULL)
    {
        return;
    }

    target_data = initialize_clipboard_component_with_callback_data
                  (target,
                   ui_manager,
                   shares_selection_changes,
                   select_all_callback,
                   connect_callbacks,
                   disconnect_callbacks);

    g_signal_connect (target, "focus_in_event",
                      G_CALLBACK (focus_changed_callback), target_data);
    g_signal_connect (target, "focus_out_event",
                      G_CALLBACK (focus_changed_callback), target_data);
    g_signal_connect (target, "destroy",
                      G_CALLBACK (target_destroy_callback), target_data);

    g_object_set_data_full (G_OBJECT (target), "Peony:clipboard_target_data",
                            target_data, (GDestroyNotify) target_data_free);

    /* Call the focus changed callback once to merge if the window is
     * already in focus.
     */
    focus_changed_callback (GTK_WIDGET (target), NULL, target_data);
}

void
peony_clipboard_set_up_editable (GtkEditable *target,
                                GtkUIManager *ui_manager,
                                gboolean shares_selection_changes)
{
    g_return_if_fail (GTK_IS_EDITABLE (target));
    g_return_if_fail (GTK_IS_UI_MANAGER (ui_manager));

    peony_clipboard_real_set_up (target, ui_manager,
                                shares_selection_changes,
                                editable_select_all_callback,
                                editable_connect_callbacks,
                                editable_disconnect_callbacks);
}

void
peony_clipboard_set_up_text_view (GtkTextView *target,
                                 GtkUIManager *ui_manager)
{
    g_return_if_fail (GTK_IS_TEXT_VIEW (target));
    g_return_if_fail (GTK_IS_UI_MANAGER (ui_manager));

    peony_clipboard_real_set_up (target, ui_manager, TRUE,
                                text_view_select_all_callback,
                                text_view_connect_callbacks,
                                text_view_disconnect_callbacks);
}

static GList *
convert_lines_to_str_list (char **lines, gboolean *cut)
{
    int i;
    GList *result;

    if (cut)
    {
        *cut = FALSE;
    }

    if (lines[0] == NULL)
    {
        return NULL;
    }

    if (strcmp (lines[0], "cut") == 0)
    {
        if (cut)
        {
            *cut = TRUE;
        }
    }
    else if (strcmp (lines[0], "copy") != 0)
    {
        return NULL;
    }

    result = NULL;
    for (i = 1; lines[i] != NULL; i++)
    {
        result = g_list_prepend (result, g_strdup (lines[i]));
    }
    return g_list_reverse (result);
}

GList*
peony_clipboard_get_uri_list_from_selection_data (GtkSelectionData *selection_data,
        gboolean *cut,
        GdkAtom copied_files_atom)
{
    GList *items;
    char **lines;

    if (gtk_selection_data_get_data_type (selection_data) != copied_files_atom
            || gtk_selection_data_get_length (selection_data) <= 0)
    {
        items = NULL;
    }
    else
    {
        guchar *data;
        /* Not sure why it's legal to assume there's an extra byte
         * past the end of the selection data that it's safe to write
         * to. But gtk_editable_selection_received does this, so I
         * think it is OK.
         */
        data = (guchar *) gtk_selection_data_get_data (selection_data);
        data[gtk_selection_data_get_length (selection_data)] = '\0';
        lines = g_strsplit (data, "\n", 0);
        items = convert_lines_to_str_list (lines, cut);
        g_strfreev (lines);
    }

    return items;
}

GtkClipboard *
peony_clipboard_get (GtkWidget *widget)
{
    return gtk_clipboard_get_for_display (gtk_widget_get_display (GTK_WIDGET (widget)),
                                          GDK_SELECTION_CLIPBOARD);
}

void
peony_clipboard_clear_if_colliding_uris (GtkWidget *widget,
                                        const GList *item_uris,
                                        GdkAtom copied_files_atom)
{
    GtkSelectionData *data;
    GList *clipboard_item_uris, *l;
    gboolean collision;

    collision = FALSE;
    data = gtk_clipboard_wait_for_contents (peony_clipboard_get (widget),
                                            copied_files_atom);
    if (data == NULL) {
        return;
    }

    clipboard_item_uris = peony_clipboard_get_uri_list_from_selection_data (data, NULL,
                          copied_files_atom);

    for (l = (GList *) item_uris; l; l = l->next) {
        if (g_list_find_custom ((GList *) item_uris, l->data,
                                (GCompareFunc) g_strcmp0)) {
            collision = TRUE;
            break;
        }
    }

    if (collision) {
        gtk_clipboard_clear (peony_clipboard_get (widget));
    }

    if (clipboard_item_uris) {
        g_list_free_full (clipboard_item_uris, g_free);
    }
}
