gtk2/gdk/gdktoplevel.c

/*
 * Copyright © 2020 Red Hat, Inc.
 *
 * 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 2.1 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/>.
 *
 * Authors: Matthias Clasen <mclasen@redhat.com>
 */

#include "config.h"

#include "gdkintl.h"
#include "gdk-private.h"
#include "gdktoplevelprivate.h"

#include <graphene-gobject.h>
#include <math.h>

/**
 * SECTION:gdktoplevel
 * @Short_description: Interface for toplevel surfaces
 * @Title: Toplevels
 * @See_also: #GdkSurface, #GdkPopup
 *
 * A #GdkToplevel is a freestanding toplevel surface.
 *
 * The #GdkToplevel interface provides useful APIs for
 * interacting with the windowing system, such as controlling
 * maximization and size of the surface, setting icons and
 * transient parents for dialogs.
 */

G_DEFINE_INTERFACE (GdkToplevel, gdk_toplevel, GDK_TYPE_SURFACE)

enum
{
  COMPUTE_SIZE,

  N_SIGNALS
};

static guint signals[N_SIGNALS] = { 0 };

static gboolean
gdk_toplevel_default_present (GdkToplevel       *toplevel,
                              GdkToplevelLayout *layout)
{
  return FALSE;
}

static gboolean
gdk_toplevel_default_minimize (GdkToplevel *toplevel)
{
  return FALSE;
}

static gboolean
gdk_toplevel_default_lower (GdkToplevel *toplevel)
{
  return FALSE;
}

static void
gdk_toplevel_default_focus (GdkToplevel *toplevel,
                            guint32      timestamp)
{
}

static gboolean
gdk_toplevel_default_show_window_menu (GdkToplevel *toplevel,
                                       GdkEvent    *event)
{
  return FALSE;
}

static gboolean
gdk_toplevel_default_supports_edge_constraints (GdkToplevel *toplevel)
{
  return FALSE;
}

static void
gdk_toplevel_default_inhibit_system_shortcuts (GdkToplevel *toplevel,
                                               GdkEvent    *event)
{
}

static void
gdk_toplevel_default_restore_system_shortcuts (GdkToplevel *toplevel)
{
}

void
gdk_toplevel_notify_compute_size (GdkToplevel     *toplevel,
                                  GdkToplevelSize *size)
{
  g_signal_emit (toplevel, signals[COMPUTE_SIZE], 0, size);
  gdk_toplevel_size_validate (size);
}

static void
gdk_toplevel_default_init (GdkToplevelInterface *iface)
{
  iface->present = gdk_toplevel_default_present;
  iface->minimize = gdk_toplevel_default_minimize;
  iface->lower = gdk_toplevel_default_lower;
  iface->focus = gdk_toplevel_default_focus;
  iface->show_window_menu = gdk_toplevel_default_show_window_menu;
  iface->supports_edge_constraints = gdk_toplevel_default_supports_edge_constraints;
  iface->inhibit_system_shortcuts = gdk_toplevel_default_inhibit_system_shortcuts;
  iface->restore_system_shortcuts = gdk_toplevel_default_restore_system_shortcuts;

  g_object_interface_install_property (iface,
      g_param_spec_flags ("state",
                          P_("State"),
                          P_("State"),
                          GDK_TYPE_TOPLEVEL_STATE, GDK_TOPLEVEL_STATE_WITHDRAWN,
                          G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
  g_object_interface_install_property (iface,
      g_param_spec_string ("title",
                           "Title",
                           "The title of the surface",
                           NULL,
                           G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY));
  g_object_interface_install_property (iface,
      g_param_spec_string ("startup-id",
                           "Startup ID",
                           "The startup ID of the surface",
                           NULL,
                           G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY));
  g_object_interface_install_property (iface,
      g_param_spec_object ("transient-for",
                           "Transient For",
                           "The transient parent of the surface",
                           GDK_TYPE_SURFACE,
                           G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY));
  g_object_interface_install_property (iface,
      g_param_spec_boolean ("modal",
                            "Modal",
                            "Whether the surface is modal",
                            FALSE,
                            G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY));
  g_object_interface_install_property (iface,
      g_param_spec_pointer ("icon-list",
                            "Icon List",
                            "The list of icon textures",
                            G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY));
  g_object_interface_install_property (iface,
      g_param_spec_boolean ("decorated",
                            "Decorated",
                            "Decorated",
                            FALSE,
                            G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY));
  g_object_interface_install_property (iface,
      g_param_spec_boolean ("deletable",
                            "Deletable",
                            "Deletable",
                            FALSE,
                            G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY));
  g_object_interface_install_property (iface,
      g_param_spec_enum ("fullscreen-mode",
                         "Fullscreen mode",
                         "Fullscreen mode",
                         GDK_TYPE_FULLSCREEN_MODE,
                         GDK_FULLSCREEN_ON_CURRENT_MONITOR,
                         G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY));
  g_object_interface_install_property (iface,
      g_param_spec_boolean ("shortcuts-inhibited",
                            "Shortcuts inhibited",
                            "Whether keyboard shortcuts are inhibited",
                            FALSE,
                            G_PARAM_READABLE | G_PARAM_EXPLICIT_NOTIFY));

  /**
   * GdkToplevel::compute-size:
   * @toplevel: a #GdkToplevel
   * @size: (type Gdk.ToplevelSize) (out caller-allocates): a #GdkToplevelSize
   *
   * Compute the desired size of the toplevel, given the information passed via
   * the #GdkToplevelSize object.
   *
   * It will normally be emitted during or after gdk_toplevel_present(),
   * depending on the configuration received by the windowing system. It may
   * also be emitted at any other point in time, in response to the windowing
   * system spontaneously changing the configuration.
   *
   * It is the responsibility of the GdkToplevel user to handle this signal;
   * failing to do so will result in an arbitrary size being used as a result.
   */
  signals[COMPUTE_SIZE] =
    g_signal_new ("compute-size",
                  GDK_TYPE_TOPLEVEL,
                  G_SIGNAL_RUN_LAST,
                  0,
                  NULL, NULL,
                  NULL,
                  G_TYPE_NONE, 1,
                  GDK_TYPE_TOPLEVEL_SIZE | G_SIGNAL_TYPE_STATIC_SCOPE);
}

guint
gdk_toplevel_install_properties (GObjectClass *object_class,
                                 guint         first_prop)
{
  g_object_class_override_property (object_class, first_prop + GDK_TOPLEVEL_PROP_STATE, "state");
  g_object_class_override_property (object_class, first_prop + GDK_TOPLEVEL_PROP_TITLE, "title");
  g_object_class_override_property (object_class, first_prop + GDK_TOPLEVEL_PROP_STARTUP_ID, "startup-id");
  g_object_class_override_property (object_class, first_prop + GDK_TOPLEVEL_PROP_TRANSIENT_FOR, "transient-for");
  g_object_class_override_property (object_class, first_prop + GDK_TOPLEVEL_PROP_MODAL, "modal");
  g_object_class_override_property (object_class, first_prop + GDK_TOPLEVEL_PROP_ICON_LIST, "icon-list");
  g_object_class_override_property (object_class, first_prop + GDK_TOPLEVEL_PROP_DECORATED, "decorated");
  g_object_class_override_property (object_class, first_prop + GDK_TOPLEVEL_PROP_DELETABLE, "deletable");
  g_object_class_override_property (object_class, first_prop + GDK_TOPLEVEL_PROP_FULLSCREEN_MODE, "fullscreen-mode");
  g_object_class_override_property (object_class, first_prop + GDK_TOPLEVEL_PROP_SHORTCUTS_INHIBITED, "shortcuts-inhibited");

  return GDK_TOPLEVEL_NUM_PROPERTIES;
}

/**
 * gdk_toplevel_present:
 * @toplevel: the #GdkToplevel to show
 * @layout: the #GdkToplevelLayout object used to layout
 *
 * Present @toplevel after having processed the #GdkToplevelLayout rules.
 * If the toplevel was previously not showing, it will be showed,
 * otherwise it will change layout according to @layout.
 *
 * GDK may emit the 'compute-size' signal to let the user of this toplevel
 * compute the preferred size of the toplevel surface. See
 * #GdkToplevel::compute-size for details.
 *
 * Presenting may fail.
 *
 * Returns: %FALSE if @toplevel failed to be presented, otherwise %TRUE.
 */
gboolean
gdk_toplevel_present (GdkToplevel       *toplevel,
                      GdkToplevelLayout *layout)
{
  g_return_val_if_fail (GDK_IS_TOPLEVEL (toplevel), FALSE);
  g_return_val_if_fail (layout != NULL, FALSE);

  return GDK_TOPLEVEL_GET_IFACE (toplevel)->present (toplevel, layout);
}

/**
 * gdk_toplevel_minimize:
 * @toplevel: a #GdkToplevel
 *
 * Asks to minimize the @toplevel.
 *
 * The windowing system may choose to ignore the request.
 *
 * Returns: %TRUE if the surface was minimized
 */
gboolean
gdk_toplevel_minimize (GdkToplevel *toplevel)
{
  g_return_val_if_fail (GDK_IS_TOPLEVEL (toplevel), FALSE);

  return GDK_TOPLEVEL_GET_IFACE (toplevel)->minimize (toplevel);
}

/**
 * gdk_toplevel_lower:
 * @toplevel: a #GdkToplevel
 *
 * Asks to lower the @toplevel below other windows.
 *
 * The windowing system may choose to ignore the request.
 *
 * Returns: %TRUE if the surface was lowered
 */
gboolean
gdk_toplevel_lower (GdkToplevel *toplevel)
{
  g_return_val_if_fail (GDK_IS_TOPLEVEL (toplevel), FALSE);

  return GDK_TOPLEVEL_GET_IFACE (toplevel)->lower (toplevel);
}

/**
 * gdk_toplevel_focus:
 * @toplevel: a #GdkToplevel
 * @timestamp: timestamp of the event triggering the surface focus
 *
 * Sets keyboard focus to @surface.
 *
 * In most cases, gtk_window_present_with_time() should be used
 * on a #GtkWindow, rather than calling this function.
 */
void
gdk_toplevel_focus (GdkToplevel *toplevel,
                   guint32       timestamp)
{
  g_return_if_fail (GDK_IS_TOPLEVEL (toplevel));

  return GDK_TOPLEVEL_GET_IFACE (toplevel)->focus (toplevel, timestamp);
}

/**
 * gdk_toplevel_get_state:
 * @toplevel: a #GdkToplevel
 *
 * Gets the bitwise OR of the currently active surface state flags,
 * from the #GdkToplevelState enumeration.
 *
 * Returns: surface state bitfield
 */
GdkToplevelState
gdk_toplevel_get_state (GdkToplevel *toplevel)
{
  GdkToplevelState state;

  g_return_val_if_fail (GDK_IS_TOPLEVEL (toplevel), 0);

  g_object_get (toplevel, "state", &state, NULL);

  return state;
}

/**
 * gdk_toplevel_set_title:
 * @toplevel: a #GdkToplevel
 * @title: title of @surface
 *
 * Sets the title of a toplevel surface, to be displayed in the titlebar,
 * in lists of windows, etc.
 */
void
gdk_toplevel_set_title (GdkToplevel *toplevel,
                        const char  *title)
{
  g_return_if_fail (GDK_IS_TOPLEVEL (toplevel));

  g_object_set (toplevel, "title", title, NULL);
}

/**
 * gdk_toplevel_set_startup_id:
 * @toplevel: a #GdkToplevel
 * @startup_id: a string with startup-notification identifier
 *
 * When using GTK, typically you should use gtk_window_set_startup_id()
 * instead of this low-level function.
 */
void
gdk_toplevel_set_startup_id (GdkToplevel *toplevel,
                             const char  *startup_id)
{
  g_return_if_fail (GDK_IS_TOPLEVEL (toplevel));

  g_object_set (toplevel, "startup-id", startup_id, NULL);
}

/**
 * gdk_toplevel_set_transient_for:
 * @toplevel: a #GdkToplevel
 * @parent: another toplevel #GdkSurface
 *
 * Indicates to the window manager that @surface is a transient dialog
 * associated with the application surface @parent. This allows the
 * window manager to do things like center @surface on @parent and
 * keep @surface above @parent.
 *
 * See gtk_window_set_transient_for() if you’re using #GtkWindow or
 * #GtkDialog.
 */
void
gdk_toplevel_set_transient_for (GdkToplevel *toplevel,
                                GdkSurface  *parent)
{
  g_return_if_fail (GDK_IS_TOPLEVEL (toplevel));

  g_object_set (toplevel, "transient-for", parent, NULL);
}

/**
 * gdk_toplevel_set_modal:
 * @toplevel: A toplevel surface
 * @modal: %TRUE if the surface is modal, %FALSE otherwise.
 *
 * The application can use this hint to tell the
 * window manager that a certain surface has modal
 * behaviour. The window manager can use this information
 * to handle modal surfaces in a special way.
 *
 * You should only use this on surfaces for which you have
 * previously called gdk_toplevel_set_transient_for().
 */
void
gdk_toplevel_set_modal (GdkToplevel *toplevel,
                        gboolean     modal)
{
  g_return_if_fail (GDK_IS_TOPLEVEL (toplevel));

  g_object_set (toplevel, "modal", modal, NULL);
}

/**
 * gdk_toplevel_set_icon_list:
 * @toplevel: a #GdkToplevel
 * @surfaces: (transfer none) (element-type GdkTexture):
 *     A list of textures to use as icon, of different sizes
 *
 * Sets a list of icons for the surface.
 *
 * One of these will be used to represent the surface in iconic form.
 * The icon may be shown in window lists or task bars. Which icon
 * size is shown depends on the window manager. The window manager
 * can scale the icon but setting several size icons can give better
 * image quality.
 *
 * Note that some platforms don't support surface icons.
 */
void
gdk_toplevel_set_icon_list (GdkToplevel *toplevel,
                            GList       *surfaces)
{
  g_return_if_fail (GDK_IS_TOPLEVEL (toplevel));

  g_object_set (toplevel, "icon-list", surfaces, NULL);
}

/**
 * gdk_toplevel_show_window_menu:
 * @toplevel: a #GdkToplevel
 * @event: a #GdkEvent to show the menu for
 *
 * Asks the windowing system to show the window menu.
 *
 * The window menu is the menu shown when right-clicking the titlebar
 * on traditional windows managed by the window manager. This is useful
 * for windows using client-side decorations, activating it with a
 * right-click on the window decorations.
 *
 * Returns: %TRUE if the window menu was shown and %FALSE otherwise.
 */
gboolean
gdk_toplevel_show_window_menu (GdkToplevel *toplevel,
                               GdkEvent    *event)
{
  g_return_val_if_fail (GDK_IS_TOPLEVEL (toplevel), FALSE);

  return GDK_TOPLEVEL_GET_IFACE (toplevel)->show_window_menu (toplevel, event);
}

/**
 * gdk_toplevel_set_decorated:
 * @toplevel: a #GdkToplevel
 * @decorated: %TRUE to request decorations
 *
 * Setting @decorated to %FALSE hints the desktop environment
 * that the surface has its own, client-side decorations and
 * does not need to have window decorations added.
 */
void
gdk_toplevel_set_decorated (GdkToplevel *toplevel,
                            gboolean     decorated)
{
  g_return_if_fail (GDK_IS_TOPLEVEL (toplevel));

  g_object_set (toplevel, "decorated", decorated, NULL);
}

/**
 * gdk_toplevel_set_deletable:
 * @toplevel: a #GdkToplevel
 * @deletable: %TRUE to request a delete button
 *
 * Setting @deletable to %TRUE hints the desktop environment
 * that it should offer the user a way to close the surface.
 */
void
gdk_toplevel_set_deletable (GdkToplevel *toplevel,
                            gboolean     deletable)
{
  g_return_if_fail (GDK_IS_TOPLEVEL (toplevel));

  g_object_set (toplevel, "deletable", deletable, NULL);
}

/**
 * gdk_toplevel_supports_edge_constraints:
 * @toplevel: a #GdkToplevel
 *
 * Returns whether the desktop environment supports
 * tiled window states.
 *
 * Returns: %TRUE if the desktop environment supports
 *     tiled window states
 */
gboolean
gdk_toplevel_supports_edge_constraints (GdkToplevel *toplevel)
{
  g_return_val_if_fail (GDK_IS_TOPLEVEL (toplevel), FALSE);

  return GDK_TOPLEVEL_GET_IFACE (toplevel)->supports_edge_constraints (toplevel);
}

/**
 * gdk_toplevel_inhibit_system_shortcuts:
 * @toplevel: the #GdkToplevel requesting system keyboard shortcuts
 * @event: (nullable): the #GdkEvent that is triggering the inhibit
 *         request, or %NULL if none is available.
 *
 * Requests that the @toplevel inhibit the system shortcuts, asking the
 * desktop environment/windowing system to let all keyboard events reach
 * the surface, as long as it is focused, instead of triggering system
 * actions.
 *
 * If granted, the rerouting remains active until the default shortcuts
 * processing is restored with gdk_toplevel_restore_system_shortcuts(),
 * or the request is revoked by the desktop environment, windowing system
 * or the user.
 *
 * A typical use case for this API is remote desktop or virtual machine
 * viewers which need to inhibit the default system keyboard shortcuts
 * so that the remote session or virtual host gets those instead of the
 * local environment.
 *
 * The windowing system or desktop environment may ask the user to grant
 * or deny the request or even choose to ignore the request entirely.
 *
 * The caller can be notified whenever the request is granted or revoked
 * by listening to the GdkToplevel::shortcuts-inhibited property.
 *
 */
void
gdk_toplevel_inhibit_system_shortcuts (GdkToplevel *toplevel,
                                       GdkEvent    *event)
{
  g_return_if_fail (GDK_IS_TOPLEVEL (toplevel));

  GDK_TOPLEVEL_GET_IFACE (toplevel)->inhibit_system_shortcuts (toplevel,
                                                               event);
}

/**
 * gdk_toplevel_restore_system_shortcuts:
 * @toplevel: a #GdkToplevel
 *
 * Restore default system keyboard shortcuts which were previously
 * requested to be inhibited by gdk_toplevel_inhibit_system_shortcuts().
 */
void
gdk_toplevel_restore_system_shortcuts (GdkToplevel *toplevel)
{
  g_return_if_fail (GDK_IS_TOPLEVEL (toplevel));

  GDK_TOPLEVEL_GET_IFACE (toplevel)->restore_system_shortcuts (toplevel);
}

/**
 * gdk_toplevel_begin_resize:
 * @toplevel: a #GdkToplevel
 * @edge: the edge or corner from which the drag is started
 * @device: (nullable): the device used for the operation
 * @button: the button being used to drag, or 0 for a keyboard-initiated drag
 * @x: surface X coordinate of mouse click that began the drag
 * @y: surface Y coordinate of mouse click that began the drag
 * @timestamp: timestamp of mouse click that began the drag (use gdk_event_get_time())
 *
 * Begins an interactive resize operation (for a toplevel surface).
 * You might use this function to implement a “window resize grip.”
 */
void
gdk_toplevel_begin_resize (GdkToplevel    *toplevel,
                           GdkSurfaceEdge  edge,
                           GdkDevice      *device,
                           int             button,
                           double          x,
                           double          y,
                           guint32         timestamp)
{
  g_return_if_fail (GDK_IS_TOPLEVEL (toplevel));

  if (device == NULL)
    {
      GdkSeat *seat = gdk_display_get_default_seat (GDK_SURFACE (toplevel)->display);
      if (button == 0)
        device = gdk_seat_get_keyboard (seat);
      else
        device = gdk_seat_get_pointer (seat);
    }

  GDK_TOPLEVEL_GET_IFACE (toplevel)->begin_resize (toplevel,
                                                   edge,
                                                   device,
                                                   button,
                                                   x, y,
                                                   timestamp);
}

/**
 * gdk_toplevel_begin_move:
 * @toplevel: a #GdkToplevel
 * @device: the device used for the operation
 * @button: the button being used to drag, or 0 for a keyboard-initiated drag
 * @x: surface X coordinate of mouse click that began the drag
 * @y: surface Y coordinate of mouse click that began the drag
 * @timestamp: timestamp of mouse click that began the drag
 *
 * Begins an interactive move operation (for a toplevel surface).
 * You might use this function to implement draggable titlebars.
 */
void
gdk_toplevel_begin_move (GdkToplevel *toplevel,
                         GdkDevice   *device,
                         int          button,
                         double       x,
                         double       y,
                         guint32      timestamp)
{
  g_return_if_fail (GDK_IS_TOPLEVEL (toplevel));

  if (device == NULL)
    {
      GdkSeat *seat = gdk_display_get_default_seat (GDK_SURFACE (toplevel)->display);
      if (button == 0)
        device = gdk_seat_get_keyboard (seat);
      else
        device = gdk_seat_get_pointer (seat);
    }

  GDK_TOPLEVEL_GET_IFACE (toplevel)->begin_move (toplevel,
                                                 device,
                                                 button,
                                                 x, y,
                                                 timestamp);
}