/* GTK - The GIMP Toolkit
 * Copyright (C) 2012 Red Hat, Inc.
 *
 * Authors:
 * - Bastien Nocera <bnocera@redhat.com>
 *
 * 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/>.
 */

/*
 * Modified by the GTK+ Team and others 2012.  See the AUTHORS
 * file for a list of people on the GTK+ Team.  See the ChangeLog
 * files for a list of changes.  These files are distributed with
 * GTK+ at ftp://ftp.gtk.org/pub/gtk/.
 */

#include "config.h"

#include "gtksearchentryprivate.h"

#include "gtkaccessible.h"
#include "gtkeditable.h"
#include "gtkboxlayout.h"
#include "gtkgestureclick.h"
#include "gtktextprivate.h"
#include "gtkimage.h"
#include "gtkintl.h"
#include "gtkprivate.h"
#include "gtkmarshalers.h"
#include "gtkstylecontext.h"
#include "gtkeventcontrollerkey.h"
#include "gtkwidgetprivate.h"
#include "a11y/gtksearchentryaccessible.h"


/**
 * SECTION:gtksearchentry
 * @Short_description: An entry which shows a search icon
 * @Title: GtkSearchEntry
 *
 * #GtkSearchEntry is an entry widget that has been tailored for use
 * as a search entry. The main aPI for interacting with a GtkSearchEntry
 * as entry is the #GtkEditable interface.
 *
 * It will show an inactive symbolic “find” icon when the search
 * entry is empty, and a symbolic “clear” icon when there is text.
 * Clicking on the “clear” icon will empty the search entry.
 *
 * To make filtering appear more reactive, it is a good idea to
 * not react to every change in the entry text immediately, but
 * only after a short delay. To support this, #GtkSearchEntry
 * emits the #GtkSearchEntry::search-changed signal which can
 * be used instead of the #GtkEditable::changed signal.
 *
 * The #GtkSearchEntry::previous-match, #GtkSearchEntry::next-match
 * and #GtkSearchEntry::stop-search signals can be used to implement
 * moving between search results and ending the search.
 *
 * Often, GtkSearchEntry will be fed events by means of being
 * placed inside a #GtkSearchBar. If that is not the case,
 * you can use gtk_search_entry_set_key_capture_widget() to let it
 * capture key input from another widget.
 *
 * # CSS Nodes
 *
 * |[<!-- language="plain" -->
 * entry.search
 * ╰── text
 * ]|
 *
 * GtkSearchEntry has a single CSS node with name entry that carries
 * a .sarch style class, and the text node is a child of that.

 */

enum {
  ACTIVATE,
  SEARCH_CHANGED,
  NEXT_MATCH,
  PREVIOUS_MATCH,
  STOP_SEARCH,
  SEARCH_STARTED,
  LAST_SIGNAL
};

enum {
  PROP_0,
  PROP_PLACEHOLDER_TEXT,
  PROP_ACTIVATES_DEFAULT,
  NUM_PROPERTIES,
};

static guint signals[LAST_SIGNAL] = { 0 };

static GParamSpec *props[NUM_PROPERTIES] = { NULL, };

typedef struct _GtkSearchEntryClass  GtkSearchEntryClass;

struct _GtkSearchEntry
{
  GtkWidget parent;

  GtkWidget *capture_widget;
  GtkEventController *capture_widget_controller;

  GtkWidget *entry;
  GtkWidget *icon;

  guint delayed_changed_id;
  gboolean content_changed;
  gboolean search_stopped;
};

struct _GtkSearchEntryClass
{
  GtkWidgetClass parent_class;

  void (* activate)       (GtkSearchEntry *entry);
  void (* search_changed) (GtkSearchEntry *entry);
  void (* next_match)     (GtkSearchEntry *entry);
  void (* previous_match) (GtkSearchEntry *entry);
  void (* stop_search)    (GtkSearchEntry *entry);
};

static void gtk_search_entry_editable_init (GtkEditableInterface *iface);

G_DEFINE_TYPE_WITH_CODE (GtkSearchEntry, gtk_search_entry, GTK_TYPE_WIDGET,
                         G_IMPLEMENT_INTERFACE (GTK_TYPE_EDITABLE,
                                                gtk_search_entry_editable_init))

/* 150 mseconds of delay */
#define DELAYED_TIMEOUT_ID 150

static void
text_changed (GtkSearchEntry *entry)
{
  entry->content_changed = TRUE;
}

static void
gtk_search_entry_finalize (GObject *object)
{
  GtkSearchEntry *entry = GTK_SEARCH_ENTRY (object);

  gtk_editable_finish_delegate (GTK_EDITABLE (entry));

  g_clear_pointer (&entry->entry, gtk_widget_unparent);
  g_clear_pointer (&entry->icon, gtk_widget_unparent);

  if (entry->delayed_changed_id > 0)
    g_source_remove (entry->delayed_changed_id);

  gtk_search_entry_set_key_capture_widget (GTK_SEARCH_ENTRY (object), NULL);

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

static void
gtk_search_entry_stop_search (GtkSearchEntry *entry)
{
  entry->search_stopped = TRUE;
}

static void
gtk_search_entry_set_property (GObject      *object,
                               guint         prop_id,
                               const GValue *value,
                               GParamSpec   *pspec)
{
  GtkSearchEntry *entry = GTK_SEARCH_ENTRY (object);

  if (gtk_editable_delegate_set_property (object, prop_id, value, pspec))
    return;

  switch (prop_id)
    {
    case PROP_PLACEHOLDER_TEXT:
      gtk_text_set_placeholder_text (GTK_TEXT (entry->entry), g_value_get_string (value));
      break;

    case PROP_ACTIVATES_DEFAULT:
      if (gtk_text_get_activates_default (GTK_TEXT (entry->entry)) != g_value_get_boolean (value))
        {
          gtk_text_set_activates_default (GTK_TEXT (entry->entry), g_value_get_boolean (value));
          g_object_notify_by_pspec (object, pspec);
        }
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
    }
}

static void
gtk_search_entry_get_property (GObject    *object,
                               guint       prop_id,
                               GValue     *value,
                               GParamSpec *pspec)
{
  GtkSearchEntry *entry = GTK_SEARCH_ENTRY (object);

  if (gtk_editable_delegate_get_property (object, prop_id, value, pspec))
    return;

  switch (prop_id)
    {
    case PROP_PLACEHOLDER_TEXT:
      g_value_set_string (value, gtk_text_get_placeholder_text (GTK_TEXT (entry->entry)));
      break;

    case PROP_ACTIVATES_DEFAULT:
      g_value_set_boolean (value, gtk_text_get_activates_default (GTK_TEXT (entry->entry)));
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
    }
}

static gboolean
gtk_search_entry_grab_focus (GtkWidget *widget)
{
  GtkSearchEntry *entry = GTK_SEARCH_ENTRY (widget);

  return gtk_text_grab_focus_without_selecting (GTK_TEXT (entry->entry));
}

static gboolean
gtk_search_entry_mnemonic_activate (GtkWidget *widget,
                                    gboolean   group_cycling)
{
  GtkSearchEntry *entry = GTK_SEARCH_ENTRY (widget);

  gtk_widget_grab_focus (entry->entry);

  return TRUE;
}

static void
gtk_search_entry_class_init (GtkSearchEntryClass *klass)
{
  GObjectClass *object_class = G_OBJECT_CLASS (klass);
  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);

  object_class->finalize = gtk_search_entry_finalize;
  object_class->get_property = gtk_search_entry_get_property;
  object_class->set_property = gtk_search_entry_set_property;

  widget_class->grab_focus = gtk_search_entry_grab_focus;
  widget_class->focus = gtk_widget_focus_child;
  widget_class->mnemonic_activate = gtk_search_entry_mnemonic_activate;

  klass->stop_search = gtk_search_entry_stop_search;

  props[PROP_PLACEHOLDER_TEXT] =
      g_param_spec_string ("placeholder-text",
                           P_("Placeholder text"),
                           P_("Show text in the entry when it’s empty and unfocused"),
                           NULL,
                           GTK_PARAM_READWRITE);

  props[PROP_ACTIVATES_DEFAULT] =
      g_param_spec_boolean ("activates-default",
                            P_("Activates default"),
                            P_("Whether to activate the default widget (such as the default button in a dialog) when Enter is pressed"),
                            FALSE,
                            GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY);

  g_object_class_install_properties (object_class, NUM_PROPERTIES, props);
  gtk_editable_install_properties (object_class, NUM_PROPERTIES);

  signals[ACTIVATE] =
    g_signal_new (I_("activate"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
                  G_STRUCT_OFFSET (GtkSearchEntryClass, activate),
                  NULL, NULL,
                  NULL,
                  G_TYPE_NONE, 0);

  /**
   * GtkSearchEntry::search-changed:
   * @entry: the entry on which the signal was emitted
   *
   * The #GtkSearchEntry::search-changed signal is emitted with a short
   * delay of 150 milliseconds after the last change to the entry text.
   */
  signals[SEARCH_CHANGED] =
    g_signal_new (I_("search-changed"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (GtkSearchEntryClass, search_changed),
                  NULL, NULL,
                  NULL,
                  G_TYPE_NONE, 0);

  /**
   * GtkSearchEntry::next-match:
   * @entry: the entry on which the signal was emitted
   *
   * The ::next-match signal is a [keybinding signal][GtkBindingSignal]
   * which gets emitted when the user initiates a move to the next match
   * for the current search string.
   *
   * Applications should connect to it, to implement moving between
   * matches.
   *
   * The default bindings for this signal is Ctrl-g.
   */
  signals[NEXT_MATCH] =
    g_signal_new (I_("next-match"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
                  G_STRUCT_OFFSET (GtkSearchEntryClass, next_match),
                  NULL, NULL,
                  NULL,
                  G_TYPE_NONE, 0);

  /**
   * GtkSearchEntry::previous-match:
   * @entry: the entry on which the signal was emitted
   *
   * The ::previous-match signal is a [keybinding signal][GtkBindingSignal]
   * which gets emitted when the user initiates a move to the previous match
   * for the current search string.
   *
   * Applications should connect to it, to implement moving between
   * matches.
   *
   * The default bindings for this signal is Ctrl-Shift-g.
   */
  signals[PREVIOUS_MATCH] =
    g_signal_new (I_("previous-match"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
                  G_STRUCT_OFFSET (GtkSearchEntryClass, previous_match),
                  NULL, NULL,
                  NULL,
                  G_TYPE_NONE, 0);

  /**
   * GtkSearchEntry::stop-search:
   * @entry: the entry on which the signal was emitted
   *
   * The ::stop-search signal is a [keybinding signal][GtkBindingSignal]
   * which gets emitted when the user stops a search via keyboard input.
   *
   * Applications should connect to it, to implement hiding the search
   * entry in this case.
   *
   * The default bindings for this signal is Escape.
   */
  signals[STOP_SEARCH] =
    g_signal_new (I_("stop-search"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
                  G_STRUCT_OFFSET (GtkSearchEntryClass, stop_search),
                  NULL, NULL,
                  NULL,
                  G_TYPE_NONE, 0);

  /**
   * GtkSearchEntry::search-started:
   * @entry: the entry on which the signal was emitted
   *
   * The ::search-started signal gets emitted when the user initiated
   * a search on the entry.
   */
  signals[SEARCH_STARTED] =
    g_signal_new (I_("search-started"),
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST, 0,
                  NULL, NULL,
                  NULL,
                  G_TYPE_NONE, 0);

  gtk_widget_class_add_binding_signal (widget_class,
                                       GDK_KEY_g, GDK_CONTROL_MASK,
                                       "next-match",
                                       NULL);
  gtk_widget_class_add_binding_signal (widget_class,
                                       GDK_KEY_g, GDK_SHIFT_MASK | GDK_CONTROL_MASK,
                                       "previous-match",
                                       NULL);
  gtk_widget_class_add_binding_signal (widget_class,
                                       GDK_KEY_Escape, 0,
                                       "stop-search",
                                       NULL);

  gtk_widget_class_set_accessible_type (widget_class, GTK_TYPE_SEARCH_ENTRY_ACCESSIBLE);
  gtk_widget_class_set_layout_manager_type (widget_class, GTK_TYPE_BOX_LAYOUT);
  gtk_widget_class_set_css_name (widget_class, I_("entry"));
}

static GtkEditable *
gtk_search_entry_get_delegate (GtkEditable *editable)
{
  return GTK_EDITABLE (GTK_SEARCH_ENTRY (editable)->entry);
}

static void
gtk_search_entry_editable_init (GtkEditableInterface *iface)
{
  iface->get_delegate = gtk_search_entry_get_delegate;
}

static void
gtk_search_entry_icon_release (GtkGestureClick *press,
                               int              n_press,
                               double           x,
                               double           y,
                               GtkSearchEntry  *entry)
{
  gtk_editable_set_text (GTK_EDITABLE (entry->entry), "");
}

static gboolean
gtk_search_entry_changed_timeout_cb (gpointer user_data)
{
  GtkSearchEntry *entry = user_data;

  g_signal_emit (entry, signals[SEARCH_CHANGED], 0);
  entry->delayed_changed_id = 0;

  return G_SOURCE_REMOVE;
}

static void
reset_timeout (GtkSearchEntry *entry)
{
  if (entry->delayed_changed_id > 0)
    g_source_remove (entry->delayed_changed_id);
  entry->delayed_changed_id = g_timeout_add (DELAYED_TIMEOUT_ID,
                                            gtk_search_entry_changed_timeout_cb,
                                            entry);
  g_source_set_name_by_id (entry->delayed_changed_id, "[gtk] gtk_search_entry_changed_timeout_cb");
}

static void
gtk_search_entry_changed (GtkEditable    *editable,
                          GtkSearchEntry *entry)
{
  const char *str;

  /* Update the icons first */
  str = gtk_editable_get_text (GTK_EDITABLE (entry->entry));

  if (str == NULL || *str == '\0')
    {
      gtk_widget_set_child_visible (entry->icon, FALSE);

      if (entry->delayed_changed_id > 0)
        {
          g_source_remove (entry->delayed_changed_id);
          entry->delayed_changed_id = 0;
        }
      g_signal_emit (entry, signals[SEARCH_CHANGED], 0);
    }
  else
    {
      gtk_widget_set_child_visible (entry->icon, TRUE);

      /* Queue up the timeout */
      reset_timeout (entry);
    }
}

static void
notify_cb (GObject    *object,
           GParamSpec *pspec,
           gpointer    data)
{
  /* The editable interface properties are already forwarded by the editable delegate setup */
  if (g_str_equal (pspec->name, "placeholder-text") ||
      g_str_equal (pspec->name, "activates-default"))
    g_object_notify (data, pspec->name);
}

static void
activate_cb (GtkText  *text,
             gpointer  data)
{
  g_signal_emit (data, signals[ACTIVATE], 0);
}

static void
gtk_search_entry_init (GtkSearchEntry *entry)
{
  GtkGesture *press;

  entry->entry = gtk_text_new ();
  gtk_widget_set_parent (entry->entry, GTK_WIDGET (entry));
  gtk_widget_set_hexpand (entry->entry, TRUE);
  gtk_editable_init_delegate (GTK_EDITABLE (entry));
  g_signal_connect_swapped (entry->entry, "changed", G_CALLBACK (text_changed), entry);
  g_signal_connect_after (entry->entry, "changed", G_CALLBACK (gtk_search_entry_changed), entry);
  g_signal_connect_swapped (entry->entry, "preedit-changed", G_CALLBACK (text_changed), entry);
  g_signal_connect (entry->entry, "notify", G_CALLBACK (notify_cb), entry);
  g_signal_connect (entry->entry, "activate", G_CALLBACK (activate_cb), entry);

  entry->icon = gtk_image_new_from_icon_name ("edit-clear-all-symbolic");
  gtk_widget_set_tooltip_text (entry->icon, _("Clear entry"));
  gtk_widget_set_parent (entry->icon, GTK_WIDGET (entry));
  gtk_widget_set_child_visible (entry->icon, FALSE);

  press = gtk_gesture_click_new ();
  g_signal_connect (press, "released", G_CALLBACK (gtk_search_entry_icon_release), entry);
  gtk_widget_add_controller (entry->icon, GTK_EVENT_CONTROLLER (press));

  gtk_widget_add_css_class (GTK_WIDGET (entry), I_("search"));
}

/**
 * gtk_search_entry_new:
 *
 * Creates a #GtkSearchEntry, with a find icon when the search field is
 * empty, and a clear icon when it isn't.
 *
 * Returns: a new #GtkSearchEntry
 */
GtkWidget *
gtk_search_entry_new (void)
{
  return GTK_WIDGET (g_object_new (GTK_TYPE_SEARCH_ENTRY, NULL));
}

gboolean
gtk_search_entry_is_keynav (guint           keyval,
                            GdkModifierType state)
{
  if (keyval == GDK_KEY_Tab       || keyval == GDK_KEY_KP_Tab ||
      keyval == GDK_KEY_Up        || keyval == GDK_KEY_KP_Up ||
      keyval == GDK_KEY_Down      || keyval == GDK_KEY_KP_Down ||
      keyval == GDK_KEY_Left      || keyval == GDK_KEY_KP_Left ||
      keyval == GDK_KEY_Right     || keyval == GDK_KEY_KP_Right ||
      keyval == GDK_KEY_Home      || keyval == GDK_KEY_KP_Home ||
      keyval == GDK_KEY_End       || keyval == GDK_KEY_KP_End ||
      keyval == GDK_KEY_Page_Up   || keyval == GDK_KEY_KP_Page_Up ||
      keyval == GDK_KEY_Page_Down || keyval == GDK_KEY_KP_Page_Down ||
      ((state & (GDK_CONTROL_MASK | GDK_ALT_MASK)) != 0))
        return TRUE;

  /* Other navigation events should get automatically
   * ignored as they will not change the content of the entry
   */
  return FALSE;
}

static gboolean
capture_widget_key_handled (GtkEventControllerKey *controller,
                            guint                  keyval,
                            guint                  keycode,
                            GdkModifierType        state,
                            GtkWidget             *widget)
{
  GtkSearchEntry *entry = GTK_SEARCH_ENTRY (widget);
  gboolean handled, was_empty;

  if (gtk_search_entry_is_keynav (keyval, state) ||
      keyval == GDK_KEY_space ||
      keyval == GDK_KEY_Menu)
    return FALSE;

  entry->content_changed = FALSE;
  entry->search_stopped = FALSE;
  was_empty = (gtk_text_get_text_length (GTK_TEXT (entry->entry)) == 0);

  handled = gtk_event_controller_key_forward (controller, entry->entry);

  if (handled && entry->content_changed && !entry->search_stopped)
    {
      if (was_empty)
        g_signal_emit (entry, signals[SEARCH_STARTED], 0);

      return GDK_EVENT_STOP;
    }

  return GDK_EVENT_PROPAGATE;
}

/**
 * gtk_search_entry_set_key_capture_widget:
 * @entry: a #GtkSearchEntry
 * @widget: (nullable) (transfer none): a #GtkWidget
 *
 * Sets @widget as the widget that @entry will capture key events from.
 *
 * Key events are consumed by the search entry to start or
 * continue a search.
 *
 * If the entry is part of a #GtkSearchBar, it is preferable
 * to call gtk_search_bar_set_key_capture_widget() instead, which
 * will reveal the entry in addition to triggering the search entry.
 **/
void
gtk_search_entry_set_key_capture_widget (GtkSearchEntry *entry,
                                         GtkWidget      *widget)
{
  g_return_if_fail (GTK_IS_SEARCH_ENTRY (entry));
  g_return_if_fail (!widget || GTK_IS_WIDGET (widget));

  if (entry->capture_widget)
    {
      gtk_widget_remove_controller (entry->capture_widget,
                                    entry->capture_widget_controller);
      g_object_remove_weak_pointer (G_OBJECT (entry->capture_widget),
                                    (gpointer *) &entry->capture_widget);
    }

  entry->capture_widget = widget;

  if (widget)
    {
      g_object_add_weak_pointer (G_OBJECT (entry->capture_widget),
                                 (gpointer *) &entry->capture_widget);

      entry->capture_widget_controller = gtk_event_controller_key_new ();
      gtk_event_controller_set_propagation_phase (entry->capture_widget_controller,
                                                  GTK_PHASE_CAPTURE);
      g_signal_connect (entry->capture_widget_controller, "key-pressed",
                        G_CALLBACK (capture_widget_key_handled), entry);
      g_signal_connect (entry->capture_widget_controller, "key-released",
                        G_CALLBACK (capture_widget_key_handled), entry);
      gtk_widget_add_controller (widget, entry->capture_widget_controller);
    }
}

/**
 * gtk_search_entry_get_key_capture_widget:
 * @entry: a #GtkSearchEntry
 *
 * Gets the widget that @entry is capturing key events from.
 *
 * Returns: (transfer none): The key capture widget.
 **/
GtkWidget *
gtk_search_entry_get_key_capture_widget (GtkSearchEntry *entry)
{
  g_return_val_if_fail (GTK_IS_SEARCH_ENTRY (entry), NULL);

  return entry->capture_widget;
}

GtkEventController *
gtk_search_entry_get_key_controller (GtkSearchEntry *entry)
{
  return gtk_text_get_key_controller (GTK_TEXT (entry->entry));
}

GtkText *
gtk_search_entry_get_text_widget (GtkSearchEntry *entry)
{
  return GTK_TEXT (entry->entry);
}