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Learning_GTK4_tree/gtk/gtkgesture.c

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2023-12-12 11:36:42 +01:00
/* GTK - The GIMP Toolkit
* Copyright (C) 2012, One Laptop Per Child.
* Copyright (C) 2014, 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 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/>.
*
* Author(s): Carlos Garnacho <carlosg@gnome.org>
*/
/**
* GtkGesture:
*
* `GtkGesture` is the base class for gesture recognition.
*
* Although `GtkGesture` is quite generalized to serve as a base for
* multi-touch gestures, it is suitable to implement single-touch and
* pointer-based gestures (using the special %NULL `GdkEventSequence`
* value for these).
*
* The number of touches that a `GtkGesture` need to be recognized is
* controlled by the [property@Gtk.Gesture:n-points] property, if a
* gesture is keeping track of less or more than that number of sequences,
* it won't check whether the gesture is recognized.
*
* As soon as the gesture has the expected number of touches, it will check
* regularly if it is recognized, the criteria to consider a gesture as
* "recognized" is left to `GtkGesture` subclasses.
*
* A recognized gesture will then emit the following signals:
*
* - [signal@Gtk.Gesture::begin] when the gesture is recognized.
* - [signal@Gtk.Gesture::update], whenever an input event is processed.
* - [signal@Gtk.Gesture::end] when the gesture is no longer recognized.
*
* ## Event propagation
*
* In order to receive events, a gesture needs to set a propagation phase
* through [method@Gtk.EventController.set_propagation_phase].
*
* In the capture phase, events are propagated from the toplevel down
* to the target widget, and gestures that are attached to containers
* above the widget get a chance to interact with the event before it
* reaches the target.
*
* In the bubble phase, events are propagated up from the target widget
* to the toplevel, and gestures that are attached to containers above
* the widget get a chance to interact with events that have not been
* handled yet.
*
* ## States of a sequence
*
* Whenever input interaction happens, a single event may trigger a cascade
* of `GtkGesture`s, both across the parents of the widget receiving the
* event and in parallel within an individual widget. It is a responsibility
* of the widgets using those gestures to set the state of touch sequences
* accordingly in order to enable cooperation of gestures around the
* `GdkEventSequence`s triggering those.
*
* Within a widget, gestures can be grouped through [method@Gtk.Gesture.group].
* Grouped gestures synchronize the state of sequences, so calling
* [method@Gtk.Gesture.set_state] on one will effectively propagate
* the state throughout the group.
*
* By default, all sequences start out in the %GTK_EVENT_SEQUENCE_NONE state,
* sequences in this state trigger the gesture event handler, but event
* propagation will continue unstopped by gestures.
*
* If a sequence enters into the %GTK_EVENT_SEQUENCE_DENIED state, the gesture
* group will effectively ignore the sequence, letting events go unstopped
* through the gesture, but the "slot" will still remain occupied while
* the touch is active.
*
* If a sequence enters in the %GTK_EVENT_SEQUENCE_CLAIMED state, the gesture
* group will grab all interaction on the sequence, by:
*
* - Setting the same sequence to %GTK_EVENT_SEQUENCE_DENIED on every other
* gesture group within the widget, and every gesture on parent widgets
* in the propagation chain.
* - Emitting [signal@Gtk.Gesture::cancel] on every gesture in widgets
* underneath in the propagation chain.
* - Stopping event propagation after the gesture group handles the event.
*
* Note: if a sequence is set early to %GTK_EVENT_SEQUENCE_CLAIMED on
* %GDK_TOUCH_BEGIN/%GDK_BUTTON_PRESS (so those events are captured before
* reaching the event widget, this implies %GTK_PHASE_CAPTURE), one similar
* event will be emulated if the sequence changes to %GTK_EVENT_SEQUENCE_DENIED.
* This way event coherence is preserved before event propagation is unstopped
* again.
*
* Sequence states can't be changed freely.
* See [method@Gtk.Gesture.set_state] to know about the possible
* lifetimes of a `GdkEventSequence`.
*
* ## Touchpad gestures
*
* On the platforms that support it, `GtkGesture` will handle transparently
* touchpad gesture events. The only precautions users of `GtkGesture` should
* do to enable this support are:
*
* - If the gesture has %GTK_PHASE_NONE, ensuring events of type
* %GDK_TOUCHPAD_SWIPE and %GDK_TOUCHPAD_PINCH are handled by the `GtkGesture`
*/
#include "config.h"
#include "gtkgesture.h"
#include "gtkwidgetprivate.h"
#include "gtkeventcontrollerprivate.h"
#include "gtkgestureprivate.h"
#include "gtktypebuiltins.h"
#include "gtkprivate.h"
#include "gtkmain.h"
#include "gtkmarshalers.h"
#include "gtknative.h"
typedef struct _GtkGesturePrivate GtkGesturePrivate;
typedef struct _PointData PointData;
enum {
PROP_N_POINTS = 1,
};
enum {
BEGIN,
END,
UPDATE,
CANCEL,
SEQUENCE_STATE_CHANGED,
N_SIGNALS
};
struct _PointData
{
GdkEvent *event;
GtkWidget *target;
double widget_x;
double widget_y;
/* Acummulators for touchpad events */
double accum_dx;
double accum_dy;
guint press_handled : 1;
guint state : 2;
};
struct _GtkGesturePrivate
{
GHashTable *points;
GdkEventSequence *last_sequence;
GdkDevice *device;
GList *group_link;
guint n_points;
guint recognized : 1;
guint touchpad : 1;
};
static guint signals[N_SIGNALS] = { 0 };
#define BUTTONS_MASK (GDK_BUTTON1_MASK | GDK_BUTTON2_MASK | GDK_BUTTON3_MASK)
#define EVENT_IS_TOUCHPAD_GESTURE(e) (gdk_event_get_event_type (e) == GDK_TOUCHPAD_SWIPE || \
gdk_event_get_event_type (e) == GDK_TOUCHPAD_PINCH || \
gdk_event_get_event_type (e) == GDK_TOUCHPAD_HOLD)
GList * _gtk_gesture_get_group_link (GtkGesture *gesture);
G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GtkGesture, gtk_gesture, GTK_TYPE_EVENT_CONTROLLER)
static void
gtk_gesture_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GtkGesturePrivate *priv = gtk_gesture_get_instance_private (GTK_GESTURE (object));
switch (prop_id)
{
case PROP_N_POINTS:
g_value_set_uint (value, priv->n_points);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
}
}
static void
gtk_gesture_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GtkGesturePrivate *priv = gtk_gesture_get_instance_private (GTK_GESTURE (object));
switch (prop_id)
{
case PROP_N_POINTS:
priv->n_points = g_value_get_uint (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
}
}
static void
gtk_gesture_finalize (GObject *object)
{
GtkGesture *gesture = GTK_GESTURE (object);
GtkGesturePrivate *priv = gtk_gesture_get_instance_private (gesture);
gtk_gesture_ungroup (gesture);
g_list_free (priv->group_link);
g_hash_table_destroy (priv->points);
G_OBJECT_CLASS (gtk_gesture_parent_class)->finalize (object);
}
static guint
_gtk_gesture_get_n_touchpad_points (GtkGesture *gesture,
gboolean only_active)
{
GtkGesturePrivate *priv;
PointData *data;
GdkEventType event_type;
GdkTouchpadGesturePhase phase = 0;
guint n_fingers = 0;
priv = gtk_gesture_get_instance_private (gesture);
if (!priv->touchpad)
return 0;
data = g_hash_table_lookup (priv->points, priv->last_sequence);
if (!data)
return 0;
event_type = gdk_event_get_event_type (data->event);
if (EVENT_IS_TOUCHPAD_GESTURE (data->event))
{
phase = gdk_touchpad_event_get_gesture_phase (data->event);
n_fingers = gdk_touchpad_event_get_n_fingers (data->event);
}
if (only_active &&
(data->state == GTK_EVENT_SEQUENCE_DENIED ||
(event_type == GDK_TOUCHPAD_SWIPE && phase == GDK_TOUCHPAD_GESTURE_PHASE_END) ||
(event_type == GDK_TOUCHPAD_PINCH && phase == GDK_TOUCHPAD_GESTURE_PHASE_END) ||
(event_type == GDK_TOUCHPAD_HOLD && phase == GDK_TOUCHPAD_GESTURE_PHASE_END)))
return 0;
return n_fingers;
}
static guint
_gtk_gesture_get_n_touch_points (GtkGesture *gesture,
gboolean only_active)
{
GtkGesturePrivate *priv;
GHashTableIter iter;
guint n_points = 0;
PointData *data;
GdkEventType event_type;
priv = gtk_gesture_get_instance_private (gesture);
g_hash_table_iter_init (&iter, priv->points);
while (g_hash_table_iter_next (&iter, NULL, (gpointer *) &data))
{
event_type = gdk_event_get_event_type (data->event);
if (only_active &&
(data->state == GTK_EVENT_SEQUENCE_DENIED ||
event_type == GDK_TOUCH_END ||
event_type == GDK_BUTTON_RELEASE))
continue;
n_points++;
}
return n_points;
}
static guint
_gtk_gesture_get_n_physical_points (GtkGesture *gesture,
gboolean only_active)
{
GtkGesturePrivate *priv;
priv = gtk_gesture_get_instance_private (gesture);
if (priv->touchpad)
return _gtk_gesture_get_n_touchpad_points (gesture, only_active);
else
return _gtk_gesture_get_n_touch_points (gesture, only_active);
}
static gboolean
gtk_gesture_check_impl (GtkGesture *gesture)
{
GtkGesturePrivate *priv;
guint n_points;
priv = gtk_gesture_get_instance_private (gesture);
n_points = _gtk_gesture_get_n_physical_points (gesture, TRUE);
return n_points == priv->n_points;
}
static void
_gtk_gesture_set_recognized (GtkGesture *gesture,
gboolean recognized,
GdkEventSequence *sequence)
{
GtkGesturePrivate *priv;
priv = gtk_gesture_get_instance_private (gesture);
if (priv->recognized == recognized)
return;
priv->recognized = recognized;
if (recognized)
g_signal_emit (gesture, signals[BEGIN], 0, sequence);
else
g_signal_emit (gesture, signals[END], 0, sequence);
}
static gboolean
_gtk_gesture_do_check (GtkGesture *gesture)
{
GtkGestureClass *gesture_class;
gboolean retval = FALSE;
gesture_class = GTK_GESTURE_GET_CLASS (gesture);
if (!gesture_class->check)
return retval;
retval = gesture_class->check (gesture);
return retval;
}
static gboolean
_gtk_gesture_has_matching_touchpoints (GtkGesture *gesture)
{
GtkGesturePrivate *priv = gtk_gesture_get_instance_private (gesture);
guint active_n_points, current_n_points;
current_n_points = _gtk_gesture_get_n_physical_points (gesture, FALSE);
active_n_points = _gtk_gesture_get_n_physical_points (gesture, TRUE);
return (active_n_points == priv->n_points &&
current_n_points == priv->n_points);
}
static gboolean
_gtk_gesture_check_recognized (GtkGesture *gesture,
GdkEventSequence *sequence)
{
GtkGesturePrivate *priv = gtk_gesture_get_instance_private (gesture);
gboolean has_matching_touchpoints;
has_matching_touchpoints = _gtk_gesture_has_matching_touchpoints (gesture);
if (priv->recognized && !has_matching_touchpoints)
_gtk_gesture_set_recognized (gesture, FALSE, sequence);
else if (!priv->recognized && has_matching_touchpoints &&
_gtk_gesture_do_check (gesture))
_gtk_gesture_set_recognized (gesture, TRUE, sequence);
return priv->recognized;
}
static void
_update_touchpad_deltas (PointData *data)
{
GdkEvent *event = data->event;
GdkTouchpadGesturePhase phase;
double dx = 0;
double dy = 0;
if (!event)
return;
if (EVENT_IS_TOUCHPAD_GESTURE (event))
{
phase = gdk_touchpad_event_get_gesture_phase (event);
if (gdk_event_get_event_type (event) != GDK_TOUCHPAD_HOLD)
gdk_touchpad_event_get_deltas (event, &dx, &dy);
if (phase == GDK_TOUCHPAD_GESTURE_PHASE_BEGIN)
data->accum_dx = data->accum_dy = 0;
else if (phase == GDK_TOUCHPAD_GESTURE_PHASE_UPDATE)
{
data->accum_dx += dx;
data->accum_dy += dy;
}
}
}
static GtkEventSequenceState
gtk_gesture_get_group_state (GtkGesture *gesture,
GdkEventSequence *sequence)
{
GtkEventSequenceState state = GTK_EVENT_SEQUENCE_NONE;
GList *group_elem;
group_elem = g_list_first (_gtk_gesture_get_group_link (gesture));
for (; group_elem; group_elem = group_elem->next)
{
if (group_elem->data == gesture)
continue;
if (!gtk_gesture_handles_sequence (group_elem->data, sequence))
continue;
state = gtk_gesture_get_sequence_state (group_elem->data, sequence);
break;
}
return state;
}
static gboolean
_gtk_gesture_update_point (GtkGesture *gesture,
GdkEvent *event,
GtkWidget *target,
double x,
double y,
gboolean add)
{
GdkEventSequence *sequence;
GtkGesturePrivate *priv;
GdkDevice *device;
gboolean existed, touchpad;
PointData *data;
device = gdk_event_get_device (event);
if (!device)
return FALSE;
priv = gtk_gesture_get_instance_private (gesture);
touchpad = EVENT_IS_TOUCHPAD_GESTURE (event);
if (add)
{
/* If the event happens with the wrong device, or
* on the wrong window, ignore.
*/
if (priv->device && priv->device != device)
return FALSE;
/* Make touchpad and touchscreen gestures mutually exclusive */
if (touchpad && g_hash_table_size (priv->points) > 0)
return FALSE;
else if (!touchpad && priv->touchpad)
return FALSE;
}
else if (!priv->device)
return FALSE;
sequence = gdk_event_get_event_sequence (event);
existed = g_hash_table_lookup_extended (priv->points, sequence,
NULL, (gpointer *) &data);
if (!existed)
{
if (!add)
return FALSE;
if (g_hash_table_size (priv->points) == 0)
{
priv->device = device;
priv->touchpad = touchpad;
}
data = g_new0 (PointData, 1);
g_hash_table_insert (priv->points, sequence, data);
}
if (data->event)
gdk_event_unref (data->event);
data->event = gdk_event_ref ((GdkEvent *)event);
g_set_object (&data->target, target);
_update_touchpad_deltas (data);
data->widget_x = x + data->accum_dx;
data->widget_y = y + data->accum_dy;
if (!existed)
{
GtkEventSequenceState state;
/* Deny the sequence right away if the expected
* number of points is exceeded, so this sequence
* can be tracked with gtk_gesture_handles_sequence().
*
* Otherwise, make the sequence inherit the same state
* from other gestures in the same group.
*/
if (_gtk_gesture_get_n_physical_points (gesture, FALSE) > priv->n_points)
state = GTK_EVENT_SEQUENCE_DENIED;
else
state = gtk_gesture_get_group_state (gesture, sequence);
G_GNUC_BEGIN_IGNORE_DEPRECATIONS
gtk_gesture_set_sequence_state (gesture, sequence, state);
G_GNUC_END_IGNORE_DEPRECATIONS
}
return TRUE;
}
static void
_gtk_gesture_check_empty (GtkGesture *gesture)
{
GtkGesturePrivate *priv;
priv = gtk_gesture_get_instance_private (gesture);
if (g_hash_table_size (priv->points) == 0)
{
priv->device = NULL;
priv->touchpad = FALSE;
}
}
static void
_gtk_gesture_remove_point (GtkGesture *gesture,
GdkEvent *event)
{
GdkEventSequence *sequence;
GtkGesturePrivate *priv;
GdkDevice *device;
sequence = gdk_event_get_event_sequence (event);
device = gdk_event_get_device (event);
priv = gtk_gesture_get_instance_private (gesture);
if (priv->device != device)
return;
g_hash_table_remove (priv->points, sequence);
_gtk_gesture_check_empty (gesture);
}
static void
_gtk_gesture_cancel_all (GtkGesture *gesture)
{
GdkEventSequence *sequence;
GtkGesturePrivate *priv;
GHashTableIter iter;
priv = gtk_gesture_get_instance_private (gesture);
g_hash_table_iter_init (&iter, priv->points);
while (g_hash_table_iter_next (&iter, (gpointer*) &sequence, NULL))
{
g_signal_emit (gesture, signals[CANCEL], 0, sequence);
g_hash_table_iter_remove (&iter);
_gtk_gesture_check_recognized (gesture, sequence);
}
_gtk_gesture_check_empty (gesture);
}
static gboolean
gesture_within_surface (GtkGesture *gesture,
GdkSurface *surface)
{
GtkWidget *widget;
widget = gtk_event_controller_get_widget (GTK_EVENT_CONTROLLER (gesture));
return surface == gtk_native_get_surface (gtk_widget_get_native (widget));
}
static gboolean
gtk_gesture_filter_event (GtkEventController *controller,
GdkEvent *event)
{
/* Even though GtkGesture handles these events, we want
* touchpad gestures disabled by default, it will be
* subclasses which punch the holes in for the events
* they can possibly handle.
*/
if (EVENT_IS_TOUCHPAD_GESTURE (event))
return FALSE;
return GTK_EVENT_CONTROLLER_CLASS (gtk_gesture_parent_class)->filter_event (controller, event);
}
static gboolean
gtk_gesture_handle_event (GtkEventController *controller,
GdkEvent *event,
double x,
double y)
{
GtkGesture *gesture = GTK_GESTURE (controller);
GdkEventSequence *sequence;
GtkGesturePrivate *priv;
GdkDevice *source_device;
gboolean was_recognized;
GdkEventType event_type;
GdkTouchpadGesturePhase phase = 0;
GdkModifierType state;
GtkWidget *target;
source_device = gdk_event_get_device (event);
if (!source_device)
return FALSE;
priv = gtk_gesture_get_instance_private (gesture);
sequence = gdk_event_get_event_sequence (event);
was_recognized = gtk_gesture_is_recognized (gesture);
event_type = gdk_event_get_event_type (event);
state = gdk_event_get_modifier_state (event);
if (EVENT_IS_TOUCHPAD_GESTURE (event))
phase = gdk_touchpad_event_get_gesture_phase (event);
target = gtk_event_controller_get_target (controller);
if (gtk_gesture_get_sequence_state (gesture, sequence) != GTK_EVENT_SEQUENCE_DENIED)
priv->last_sequence = sequence;
if (event_type == GDK_BUTTON_PRESS ||
event_type == GDK_TOUCH_BEGIN ||
(EVENT_IS_TOUCHPAD_GESTURE (event) &&
phase == GDK_TOUCHPAD_GESTURE_PHASE_BEGIN &&
gdk_touchpad_event_get_n_fingers (event) == priv->n_points))
{
if (_gtk_gesture_update_point (gesture, event, target, x, y, TRUE))
{
gboolean triggered_recognition;
triggered_recognition =
!was_recognized && _gtk_gesture_has_matching_touchpoints (gesture);
if (_gtk_gesture_check_recognized (gesture, sequence))
{
PointData *data;
data = g_hash_table_lookup (priv->points, sequence);
/* If the sequence was claimed early, the press event will be consumed */
if (gtk_gesture_get_sequence_state (gesture, sequence) == GTK_EVENT_SEQUENCE_CLAIMED)
data->press_handled = TRUE;
}
else if (triggered_recognition && g_hash_table_size (priv->points) == 0)
{
/* Recognition was triggered, but the gesture reset during
* ::begin emission. Still, recognition was strictly triggered,
* so the event should be consumed.
*/
return TRUE;
}
}
}
else if (event_type == GDK_BUTTON_RELEASE ||
event_type == GDK_TOUCH_END ||
(EVENT_IS_TOUCHPAD_GESTURE (event) &&
phase == GDK_TOUCHPAD_GESTURE_PHASE_END &&
gdk_touchpad_event_get_n_fingers (event) == priv->n_points))
{
gboolean was_claimed = FALSE;
if (_gtk_gesture_update_point (gesture, event, target, x, y, FALSE))
{
if (was_recognized &&
_gtk_gesture_check_recognized (gesture, sequence))
g_signal_emit (gesture, signals[UPDATE], 0, sequence);
was_claimed =
gtk_gesture_get_sequence_state (gesture, sequence) == GTK_EVENT_SEQUENCE_CLAIMED;
_gtk_gesture_remove_point (gesture, event);
}
return was_claimed && was_recognized;
}
else if (event_type == GDK_MOTION_NOTIFY ||
event_type == GDK_TOUCH_UPDATE ||
(EVENT_IS_TOUCHPAD_GESTURE (event) &&
phase == GDK_TOUCHPAD_GESTURE_PHASE_UPDATE &&
gdk_touchpad_event_get_n_fingers (event) == priv->n_points))
{
if (event_type == GDK_MOTION_NOTIFY)
{
if ((state & BUTTONS_MASK) == 0)
return FALSE;
}
if (_gtk_gesture_update_point (gesture, event, target, x, y, FALSE) &&
_gtk_gesture_check_recognized (gesture, sequence))
g_signal_emit (gesture, signals[UPDATE], 0, sequence);
}
else if (event_type == GDK_TOUCH_CANCEL)
{
if (!priv->touchpad)
_gtk_gesture_cancel_sequence (gesture, sequence);
}
else if (EVENT_IS_TOUCHPAD_GESTURE (event) &&
phase == GDK_TOUCHPAD_GESTURE_PHASE_CANCEL &&
gdk_touchpad_event_get_n_fingers (event) == priv->n_points)
{
if (priv->touchpad)
_gtk_gesture_cancel_sequence (gesture, sequence);
}
else if (event_type == GDK_GRAB_BROKEN)
{
GdkSurface *surface;
surface = gdk_grab_broken_event_get_grab_surface (event);
if (!surface || !gesture_within_surface (gesture, surface))
_gtk_gesture_cancel_all (gesture);
return FALSE;
}
else
{
/* Unhandled event */
return FALSE;
}
if (gtk_gesture_get_sequence_state (gesture, sequence) != GTK_EVENT_SEQUENCE_CLAIMED)
return FALSE;
return priv->recognized;
}
static void
gtk_gesture_reset (GtkEventController *controller)
{
_gtk_gesture_cancel_all (GTK_GESTURE (controller));
}
static void
gtk_gesture_class_init (GtkGestureClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
GtkEventControllerClass *controller_class = GTK_EVENT_CONTROLLER_CLASS (klass);
object_class->get_property = gtk_gesture_get_property;
object_class->set_property = gtk_gesture_set_property;
object_class->finalize = gtk_gesture_finalize;
controller_class->filter_event = gtk_gesture_filter_event;
controller_class->handle_event = gtk_gesture_handle_event;
controller_class->reset = gtk_gesture_reset;
klass->check = gtk_gesture_check_impl;
/**
* GtkGesture:n-points:
*
* The number of touch points that trigger
* recognition on this gesture.
*/
g_object_class_install_property (object_class,
PROP_N_POINTS,
g_param_spec_uint ("n-points", NULL, NULL,
1, G_MAXUINT, 1,
GTK_PARAM_READWRITE |
G_PARAM_CONSTRUCT_ONLY));
/**
* GtkGesture::begin:
* @gesture: the object which received the signal
* @sequence: (nullable): the `GdkEventSequence` that made the gesture
* to be recognized
*
* Emitted when the gesture is recognized.
*
* This means the number of touch sequences matches
* [property@Gtk.Gesture:n-points].
*
* Note: These conditions may also happen when an extra touch
* (eg. a third touch on a 2-touches gesture) is lifted, in that
* situation @sequence won't pertain to the current set of active
* touches, so don't rely on this being true.
*/
signals[BEGIN] =
g_signal_new (I_("begin"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GtkGestureClass, begin),
NULL, NULL, NULL,
G_TYPE_NONE, 1, GDK_TYPE_EVENT_SEQUENCE);
/**
* GtkGesture::end:
* @gesture: the object which received the signal
* @sequence: (nullable): the `GdkEventSequence` that made gesture
* recognition to finish
*
* Emitted when @gesture either stopped recognizing the event
* sequences as something to be handled, or the number of touch
* sequences became higher or lower than [property@Gtk.Gesture:n-points].
*
* Note: @sequence might not pertain to the group of sequences that
* were previously triggering recognition on @gesture (ie. a just
* pressed touch sequence that exceeds [property@Gtk.Gesture:n-points]).
* This situation may be detected by checking through
* [method@Gtk.Gesture.handles_sequence].
*/
signals[END] =
g_signal_new (I_("end"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GtkGestureClass, end),
NULL, NULL, NULL,
G_TYPE_NONE, 1, GDK_TYPE_EVENT_SEQUENCE);
/**
* GtkGesture::update:
* @gesture: the object which received the signal
* @sequence: (nullable): the `GdkEventSequence` that was updated
*
* Emitted whenever an event is handled while the gesture is recognized.
*
* @sequence is guaranteed to pertain to the set of active touches.
*/
signals[UPDATE] =
g_signal_new (I_("update"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GtkGestureClass, update),
NULL, NULL, NULL,
G_TYPE_NONE, 1, GDK_TYPE_EVENT_SEQUENCE);
/**
* GtkGesture::cancel:
* @gesture: the object which received the signal
* @sequence: (nullable): the `GdkEventSequence` that was cancelled
*
* Emitted whenever a sequence is cancelled.
*
* This usually happens on active touches when
* [method@Gtk.EventController.reset] is called on @gesture
* (manually, due to grabs...), or the individual @sequence
* was claimed by parent widgets' controllers (see
* [method@Gtk.Gesture.set_sequence_state]).
*
* @gesture must forget everything about @sequence as in
* response to this signal.
*/
signals[CANCEL] =
g_signal_new (I_("cancel"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GtkGestureClass, cancel),
NULL, NULL, NULL,
G_TYPE_NONE, 1, GDK_TYPE_EVENT_SEQUENCE);
/**
* GtkGesture::sequence-state-changed:
* @gesture: the object which received the signal
* @sequence: (nullable): the `GdkEventSequence` that was cancelled
* @state: the new sequence state
*
* Emitted whenever a sequence state changes.
*
* See [method@Gtk.Gesture.set_sequence_state] to know
* more about the expectable sequence lifetimes.
*/
signals[SEQUENCE_STATE_CHANGED] =
g_signal_new (I_("sequence-state-changed"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GtkGestureClass, sequence_state_changed),
NULL, NULL,
_gtk_marshal_VOID__BOXED_ENUM,
G_TYPE_NONE, 2, GDK_TYPE_EVENT_SEQUENCE,
GTK_TYPE_EVENT_SEQUENCE_STATE);
g_signal_set_va_marshaller (signals[SEQUENCE_STATE_CHANGED],
G_TYPE_FROM_CLASS (klass),
_gtk_marshal_VOID__BOXED_ENUMv);
}
static void
free_point_data (gpointer data)
{
PointData *point = data;
if (point->event)
gdk_event_unref (point->event);
if (point->target)
g_object_unref (point->target);
g_free (point);
}
static void
gtk_gesture_init (GtkGesture *gesture)
{
GtkGesturePrivate *priv;
priv = gtk_gesture_get_instance_private (gesture);
priv->points = g_hash_table_new_full (NULL, NULL, NULL,
(GDestroyNotify) free_point_data);
priv->group_link = g_list_prepend (NULL, gesture);
}
/**
* gtk_gesture_get_device:
* @gesture: a `GtkGesture`
*
* Returns the logical `GdkDevice` that is currently operating
* on @gesture.
*
* This returns %NULL if the gesture is not being interacted.
*
* Returns: (nullable) (transfer none): a `GdkDevice`
*/
GdkDevice *
gtk_gesture_get_device (GtkGesture *gesture)
{
GtkGesturePrivate *priv;
g_return_val_if_fail (GTK_IS_GESTURE (gesture), NULL);
priv = gtk_gesture_get_instance_private (gesture);
return priv->device;
}
/**
* gtk_gesture_get_sequence_state:
* @gesture: a `GtkGesture`
* @sequence: a `GdkEventSequence`
*
* Returns the @sequence state, as seen by @gesture.
*
* Returns: The sequence state in @gesture
*/
GtkEventSequenceState
gtk_gesture_get_sequence_state (GtkGesture *gesture,
GdkEventSequence *sequence)
{
GtkGesturePrivate *priv;
PointData *data;
g_return_val_if_fail (GTK_IS_GESTURE (gesture),
GTK_EVENT_SEQUENCE_NONE);
priv = gtk_gesture_get_instance_private (gesture);
data = g_hash_table_lookup (priv->points, sequence);
if (!data)
return GTK_EVENT_SEQUENCE_NONE;
return data->state;
}
/**
* gtk_gesture_set_sequence_state:
* @gesture: a `GtkGesture`
* @sequence: a `GdkEventSequence`
* @state: the sequence state
*
* Sets the state of @sequence in @gesture.
*
* Sequences start in state %GTK_EVENT_SEQUENCE_NONE, and whenever
* they change state, they can never go back to that state. Likewise,
* sequences in state %GTK_EVENT_SEQUENCE_DENIED cannot turn back to
* a not denied state. With these rules, the lifetime of an event
* sequence is constrained to the next four:
*
* * None
* * None → Denied
* * None → Claimed
* * None → Claimed → Denied
*
* Note: Due to event handling ordering, it may be unsafe to set the
* state on another gesture within a [signal@Gtk.Gesture::begin] signal
* handler, as the callback might be executed before the other gesture
* knows about the sequence. A safe way to perform this could be:
*
* ```c
* static void
* first_gesture_begin_cb (GtkGesture *first_gesture,
* GdkEventSequence *sequence,
* gpointer user_data)
* {
* gtk_gesture_set_sequence_state (first_gesture, sequence, GTK_EVENT_SEQUENCE_CLAIMED);
* gtk_gesture_set_sequence_state (second_gesture, sequence, GTK_EVENT_SEQUENCE_DENIED);
* }
*
* static void
* second_gesture_begin_cb (GtkGesture *second_gesture,
* GdkEventSequence *sequence,
* gpointer user_data)
* {
* if (gtk_gesture_get_sequence_state (first_gesture, sequence) == GTK_EVENT_SEQUENCE_CLAIMED)
* gtk_gesture_set_sequence_state (second_gesture, sequence, GTK_EVENT_SEQUENCE_DENIED);
* }
* ```
*
* If both gestures are in the same group, just set the state on
* the gesture emitting the event, the sequence will be already
* be initialized to the group's global state when the second
* gesture processes the event.
*
* Returns: %TRUE if @sequence is handled by @gesture,
* and the state is changed successfully
*
* Deprecated: 4.10. Use [method@Gtk.Gesture.set_state]
*/
gboolean
gtk_gesture_set_sequence_state (GtkGesture *gesture,
GdkEventSequence *sequence,
GtkEventSequenceState state)
{
GtkGesturePrivate *priv;
PointData *data;
g_return_val_if_fail (GTK_IS_GESTURE (gesture), FALSE);
g_return_val_if_fail (state >= GTK_EVENT_SEQUENCE_NONE &&
state <= GTK_EVENT_SEQUENCE_DENIED, FALSE);
priv = gtk_gesture_get_instance_private (gesture);
data = g_hash_table_lookup (priv->points, sequence);
if (!data)
return FALSE;
if (data->state == state)
return FALSE;
/* denied sequences remain denied */
if (data->state == GTK_EVENT_SEQUENCE_DENIED)
return FALSE;
/* Sequences can't go from claimed/denied to none */
if (state == GTK_EVENT_SEQUENCE_NONE &&
data->state != GTK_EVENT_SEQUENCE_NONE)
return FALSE;
data->state = state;
gtk_widget_cancel_event_sequence (gtk_event_controller_get_widget (GTK_EVENT_CONTROLLER (gesture)),
gesture, sequence, state);
g_signal_emit (gesture, signals[SEQUENCE_STATE_CHANGED], 0,
sequence, state);
if (state == GTK_EVENT_SEQUENCE_DENIED)
_gtk_gesture_check_recognized (gesture, sequence);
return TRUE;
}
/**
* gtk_gesture_set_state:
* @gesture: a `GtkGesture`
* @state: the sequence state
*
* Sets the state of all sequences that @gesture is currently
* interacting with.
*
* Sequences start in state %GTK_EVENT_SEQUENCE_NONE, and whenever
* they change state, they can never go back to that state. Likewise,
* sequences in state %GTK_EVENT_SEQUENCE_DENIED cannot turn back to
* a not denied state. With these rules, the lifetime of an event
* sequence is constrained to the next four:
*
* * None
* * None → Denied
* * None → Claimed
* * None → Claimed → Denied
*
* Note: Due to event handling ordering, it may be unsafe to set the
* state on another gesture within a [signal@Gtk.Gesture::begin] signal
* handler, as the callback might be executed before the other gesture
* knows about the sequence. A safe way to perform this could be:
*
* ```c
* static void
* first_gesture_begin_cb (GtkGesture *first_gesture,
* GdkEventSequence *sequence,
* gpointer user_data)
* {
* gtk_gesture_set_state (first_gesture, GTK_EVENT_SEQUENCE_CLAIMED);
* gtk_gesture_set_state (second_gesture, GTK_EVENT_SEQUENCE_DENIED);
* }
*
* static void
* second_gesture_begin_cb (GtkGesture *second_gesture,
* GdkEventSequence *sequence,
* gpointer user_data)
* {
* if (gtk_gesture_get_sequence_state (first_gesture, sequence) == GTK_EVENT_SEQUENCE_CLAIMED)
* gtk_gesture_set_state (second_gesture, GTK_EVENT_SEQUENCE_DENIED);
* }
* ```
*
* If both gestures are in the same group, just set the state on
* the gesture emitting the event, the sequence will be already
* be initialized to the group's global state when the second
* gesture processes the event.
*
* Returns: %TRUE if the state of at least one sequence
* was changed successfully
*/
gboolean
gtk_gesture_set_state (GtkGesture *gesture,
GtkEventSequenceState state)
{
gboolean handled = FALSE;
GtkGesturePrivate *priv;
GList *sequences, *l;
g_return_val_if_fail (GTK_IS_GESTURE (gesture), FALSE);
g_return_val_if_fail (state >= GTK_EVENT_SEQUENCE_NONE &&
state <= GTK_EVENT_SEQUENCE_DENIED, FALSE);
priv = gtk_gesture_get_instance_private (gesture);
sequences = g_hash_table_get_keys (priv->points);
G_GNUC_BEGIN_IGNORE_DEPRECATIONS
for (l = sequences; l; l = l->next)
handled |= gtk_gesture_set_sequence_state (gesture, l->data, state);
G_GNUC_END_IGNORE_DEPRECATIONS
g_list_free (sequences);
return handled;
}
/**
* gtk_gesture_get_sequences:
* @gesture: a `GtkGesture`
*
* Returns the list of `GdkEventSequences` currently being interpreted
* by @gesture.
*
* Returns: (transfer container) (element-type GdkEventSequence): A list
* of `GdkEventSequence`, the list elements are owned by GTK and must
* not be freed or modified, the list itself must be deleted
* through g_list_free()
*/
GList *
gtk_gesture_get_sequences (GtkGesture *gesture)
{
GdkEventSequence *sequence;
GtkGesturePrivate *priv;
GList *sequences = NULL;
GHashTableIter iter;
PointData *data;
GdkEventType event_type;
g_return_val_if_fail (GTK_IS_GESTURE (gesture), NULL);
priv = gtk_gesture_get_instance_private (gesture);
g_hash_table_iter_init (&iter, priv->points);
while (g_hash_table_iter_next (&iter, (gpointer *) &sequence, (gpointer *) &data))
{
if (data->state == GTK_EVENT_SEQUENCE_DENIED)
continue;
event_type = gdk_event_get_event_type (data->event);
if (event_type == GDK_TOUCH_END ||
event_type == GDK_BUTTON_RELEASE)
continue;
sequences = g_list_prepend (sequences, sequence);
}
return sequences;
}
/**
* gtk_gesture_get_last_updated_sequence:
* @gesture: a `GtkGesture`
*
* Returns the `GdkEventSequence` that was last updated on @gesture.
*
* Returns: (transfer none) (nullable): The last updated sequence
*/
GdkEventSequence *
gtk_gesture_get_last_updated_sequence (GtkGesture *gesture)
{
GtkGesturePrivate *priv;
g_return_val_if_fail (GTK_IS_GESTURE (gesture), NULL);
priv = gtk_gesture_get_instance_private (gesture);
return priv->last_sequence;
}
/**
* gtk_gesture_get_last_event:
* @gesture: a `GtkGesture`
* @sequence: (nullable): a `GdkEventSequence`
*
* Returns the last event that was processed for @sequence.
*
* Note that the returned pointer is only valid as long as the
* @sequence is still interpreted by the @gesture. If in doubt,
* you should make a copy of the event.
*
* Returns: (transfer none) (nullable): The last event from @sequence
*/
GdkEvent *
gtk_gesture_get_last_event (GtkGesture *gesture,
GdkEventSequence *sequence)
{
GtkGesturePrivate *priv;
PointData *data;
g_return_val_if_fail (GTK_IS_GESTURE (gesture), NULL);
priv = gtk_gesture_get_instance_private (gesture);
data = g_hash_table_lookup (priv->points, sequence);
if (!data)
return NULL;
return data->event;
}
/*
* gtk_gesture_get_last_target:
* @gesture: a `GtkGesture`
* @sequence: event sequence
*
* Returns the widget that the last event was targeted at.
*
* See [method@Gtk.Gesture.get_last_event].
*
* Returns: (transfer none) (nullable): The target of the last event
*/
GtkWidget *
gtk_gesture_get_last_target (GtkGesture *gesture,
GdkEventSequence *sequence)
{
GtkGesturePrivate *priv;
PointData *data;
g_return_val_if_fail (GTK_IS_GESTURE (gesture), NULL);
priv = gtk_gesture_get_instance_private (gesture);
data = g_hash_table_lookup (priv->points, sequence);
if (!data)
return NULL;
return data->target;
}
/**
* gtk_gesture_get_point:
* @gesture: a `GtkGesture`
* @sequence: (nullable): a `GdkEventSequence`, or %NULL for pointer events
* @x: (out) (optional): return location for X axis of the sequence coordinates
* @y: (out) (optional): return location for Y axis of the sequence coordinates
*
* If @sequence is currently being interpreted by @gesture,
* returns %TRUE and fills in @x and @y with the last coordinates
* stored for that event sequence.
*
* The coordinates are always relative to the widget allocation.
*
* Returns: %TRUE if @sequence is currently interpreted
*/
gboolean
gtk_gesture_get_point (GtkGesture *gesture,
GdkEventSequence *sequence,
double *x,
double *y)
{
GtkGesturePrivate *priv;
PointData *data;
g_return_val_if_fail (GTK_IS_GESTURE (gesture), FALSE);
priv = gtk_gesture_get_instance_private (gesture);
if (!g_hash_table_lookup_extended (priv->points, sequence,
NULL, (gpointer *) &data))
return FALSE;
if (x)
*x = data->widget_x;
if (y)
*y = data->widget_y;
return TRUE;
}
gboolean
_gtk_gesture_get_last_update_time (GtkGesture *gesture,
GdkEventSequence *sequence,
guint32 *evtime)
{
GtkGesturePrivate *priv;
PointData *data;
g_return_val_if_fail (GTK_IS_GESTURE (gesture), FALSE);
priv = gtk_gesture_get_instance_private (gesture);
if (!g_hash_table_lookup_extended (priv->points, sequence,
NULL, (gpointer *) &data))
return FALSE;
if (evtime)
*evtime = gdk_event_get_time (data->event);
return TRUE;
};
/**
* gtk_gesture_get_bounding_box:
* @gesture: a `GtkGesture`
* @rect: (out): bounding box containing all active touches.
*
* If there are touch sequences being currently handled by @gesture,
* returns %TRUE and fills in @rect with the bounding box containing
* all active touches.
*
* Otherwise, %FALSE will be returned.
*
* Note: This function will yield unexpected results on touchpad
* gestures. Since there is no correlation between physical and
* pixel distances, these will look as if constrained in an
* infinitely small area, @rect width and height will thus be 0
* regardless of the number of touchpoints.
*
* Returns: %TRUE if there are active touches, %FALSE otherwise
*/
gboolean
gtk_gesture_get_bounding_box (GtkGesture *gesture,
GdkRectangle *rect)
{
GtkGesturePrivate *priv;
double x1, y1, x2, y2;
GHashTableIter iter;
guint n_points = 0;
PointData *data;
GdkEventType event_type;
g_return_val_if_fail (GTK_IS_GESTURE (gesture), FALSE);
g_return_val_if_fail (rect != NULL, FALSE);
priv = gtk_gesture_get_instance_private (gesture);
x1 = y1 = G_MAXDOUBLE;
x2 = y2 = -G_MAXDOUBLE;
g_hash_table_iter_init (&iter, priv->points);
while (g_hash_table_iter_next (&iter, NULL, (gpointer *) &data))
{
if (data->state == GTK_EVENT_SEQUENCE_DENIED)
continue;
event_type = gdk_event_get_event_type (data->event);
if (event_type == GDK_TOUCH_END ||
event_type == GDK_BUTTON_RELEASE)
continue;
n_points++;
x1 = MIN (x1, data->widget_x);
y1 = MIN (y1, data->widget_y);
x2 = MAX (x2, data->widget_x);
y2 = MAX (y2, data->widget_y);
}
if (n_points == 0)
return FALSE;
rect->x = x1;
rect->y = y1;
rect->width = x2 - x1;
rect->height = y2 - y1;
return TRUE;
}
/**
* gtk_gesture_get_bounding_box_center:
* @gesture: a `GtkGesture`
* @x: (out): X coordinate for the bounding box center
* @y: (out): Y coordinate for the bounding box center
*
* If there are touch sequences being currently handled by @gesture,
* returns %TRUE and fills in @x and @y with the center of the bounding
* box containing all active touches.
*
* Otherwise, %FALSE will be returned.
*
* Returns: %FALSE if no active touches are present, %TRUE otherwise
*/
gboolean
gtk_gesture_get_bounding_box_center (GtkGesture *gesture,
double *x,
double *y)
{
GdkEvent *last_event;
GdkRectangle rect;
GdkEventSequence *sequence;
g_return_val_if_fail (GTK_IS_GESTURE (gesture), FALSE);
g_return_val_if_fail (x != NULL && y != NULL, FALSE);
sequence = gtk_gesture_get_last_updated_sequence (gesture);
last_event = gtk_gesture_get_last_event (gesture, sequence);
if (EVENT_IS_TOUCHPAD_GESTURE (last_event))
return gtk_gesture_get_point (gesture, sequence, x, y);
else if (!gtk_gesture_get_bounding_box (gesture, &rect))
return FALSE;
*x = rect.x + rect.width / 2;
*y = rect.y + rect.height / 2;
return TRUE;
}
/**
* gtk_gesture_is_active:
* @gesture: a `GtkGesture`
*
* Returns %TRUE if the gesture is currently active.
*
* A gesture is active while there are touch sequences
* interacting with it.
*
* Returns: %TRUE if gesture is active
*/
gboolean
gtk_gesture_is_active (GtkGesture *gesture)
{
g_return_val_if_fail (GTK_IS_GESTURE (gesture), FALSE);
return _gtk_gesture_get_n_physical_points (gesture, TRUE) != 0;
}
/**
* gtk_gesture_is_recognized:
* @gesture: a `GtkGesture`
*
* Returns %TRUE if the gesture is currently recognized.
*
* A gesture is recognized if there are as many interacting
* touch sequences as required by @gesture.
*
* Returns: %TRUE if gesture is recognized
*/
gboolean
gtk_gesture_is_recognized (GtkGesture *gesture)
{
GtkGesturePrivate *priv;
g_return_val_if_fail (GTK_IS_GESTURE (gesture), FALSE);
priv = gtk_gesture_get_instance_private (gesture);
return priv->recognized;
}
gboolean
_gtk_gesture_check (GtkGesture *gesture)
{
GtkGesturePrivate *priv;
g_return_val_if_fail (GTK_IS_GESTURE (gesture), FALSE);
priv = gtk_gesture_get_instance_private (gesture);
return _gtk_gesture_check_recognized (gesture, priv->last_sequence);
}
/**
* gtk_gesture_handles_sequence:
* @gesture: a `GtkGesture`
* @sequence: (nullable): a `GdkEventSequence`
*
* Returns %TRUE if @gesture is currently handling events
* corresponding to @sequence.
*
* Returns: %TRUE if @gesture is handling @sequence, %FALSE otherwise
*/
gboolean
gtk_gesture_handles_sequence (GtkGesture *gesture,
GdkEventSequence *sequence)
{
GtkGesturePrivate *priv;
PointData *data;
g_return_val_if_fail (GTK_IS_GESTURE (gesture), FALSE);
priv = gtk_gesture_get_instance_private (gesture);
data = g_hash_table_lookup (priv->points, sequence);
if (!data)
return FALSE;
if (data->state == GTK_EVENT_SEQUENCE_DENIED)
return FALSE;
return TRUE;
}
gboolean
_gtk_gesture_cancel_sequence (GtkGesture *gesture,
GdkEventSequence *sequence)
{
GtkGesturePrivate *priv;
PointData *data;
g_return_val_if_fail (GTK_IS_GESTURE (gesture), FALSE);
priv = gtk_gesture_get_instance_private (gesture);
data = g_hash_table_lookup (priv->points, sequence);
if (!data)
return FALSE;
g_signal_emit (gesture, signals[CANCEL], 0, sequence);
_gtk_gesture_remove_point (gesture, data->event);
_gtk_gesture_check_recognized (gesture, sequence);
return TRUE;
}
GList *
_gtk_gesture_get_group_link (GtkGesture *gesture)
{
GtkGesturePrivate *priv;
priv = gtk_gesture_get_instance_private (gesture);
return priv->group_link;
}
/**
* gtk_gesture_group:
* @gesture: a `GtkGesture`
* @group_gesture: `GtkGesture` to group @gesture with
*
* Adds @gesture to the same group than @group_gesture.
*
* Gestures are by default isolated in their own groups.
*
* Both gestures must have been added to the same widget before
* they can be grouped.
*
* When gestures are grouped, the state of `GdkEventSequences`
* is kept in sync for all of those, so calling
* [method@Gtk.Gesture.set_sequence_state], on one will transfer
* the same value to the others.
*
* Groups also perform an "implicit grabbing" of sequences, if a
* `GdkEventSequence` state is set to %GTK_EVENT_SEQUENCE_CLAIMED
* on one group, every other gesture group attached to the same
* `GtkWidget` will switch the state for that sequence to
* %GTK_EVENT_SEQUENCE_DENIED.
*/
void
gtk_gesture_group (GtkGesture *gesture,
GtkGesture *group_gesture)
{
GList *link, *group_link, *next;
g_return_if_fail (GTK_IS_GESTURE (gesture));
g_return_if_fail (GTK_IS_GESTURE (group_gesture));
g_return_if_fail (gtk_event_controller_get_widget (GTK_EVENT_CONTROLLER (group_gesture)) ==
gtk_event_controller_get_widget (GTK_EVENT_CONTROLLER (gesture)));
link = _gtk_gesture_get_group_link (gesture);
if (link->prev || link->next)
{
if (gtk_gesture_is_grouped_with (gesture, group_gesture))
return;
gtk_gesture_ungroup (gesture);
}
group_link = _gtk_gesture_get_group_link (group_gesture);
next = group_link->next;
/* Rewire link so it's inserted after the group_gesture elem */
link->prev = group_link;
link->next = next;
group_link->next = link;
if (next)
next->prev = link;
}
/**
* gtk_gesture_ungroup:
* @gesture: a `GtkGesture`
*
* Separates @gesture into an isolated group.
*/
void
gtk_gesture_ungroup (GtkGesture *gesture)
{
GList *link, *prev, *next;
g_return_if_fail (GTK_IS_GESTURE (gesture));
link = _gtk_gesture_get_group_link (gesture);
prev = link->prev;
next = link->next;
/* Detach link from the group chain */
if (prev)
prev->next = next;
if (next)
next->prev = prev;
link->next = link->prev = NULL;
}
/**
* gtk_gesture_get_group:
* @gesture: a `GtkGesture`
*
* Returns all gestures in the group of @gesture
*
* Returns: (element-type GtkGesture) (transfer container): The list
* of `GtkGesture`s, free with g_list_free()
*/
GList *
gtk_gesture_get_group (GtkGesture *gesture)
{
GList *link;
g_return_val_if_fail (GTK_IS_GESTURE (gesture), NULL);
link = _gtk_gesture_get_group_link (gesture);
return g_list_copy (g_list_first (link));
}
/**
* gtk_gesture_is_grouped_with:
* @gesture: a `GtkGesture`
* @other: another `GtkGesture`
*
* Returns %TRUE if both gestures pertain to the same group.
*
* Returns: whether the gestures are grouped
*/
gboolean
gtk_gesture_is_grouped_with (GtkGesture *gesture,
GtkGesture *other)
{
GList *link;
g_return_val_if_fail (GTK_IS_GESTURE (gesture), FALSE);
g_return_val_if_fail (GTK_IS_GESTURE (other), FALSE);
link = _gtk_gesture_get_group_link (gesture);
link = g_list_first (link);
return g_list_find (link, other) != NULL;
}
gboolean
_gtk_gesture_handled_sequence_press (GtkGesture *gesture,
GdkEventSequence *sequence)
{
GtkGesturePrivate *priv;
PointData *data;
g_return_val_if_fail (GTK_IS_GESTURE (gesture), FALSE);
priv = gtk_gesture_get_instance_private (gesture);
data = g_hash_table_lookup (priv->points, sequence);
if (!data)
return FALSE;
return data->press_handled;
}
gboolean
_gtk_gesture_get_pointer_emulating_sequence (GtkGesture *gesture,
GdkEventSequence **sequence)
{
GtkGesturePrivate *priv;
GdkEventSequence *seq;
GHashTableIter iter;
PointData *data;
g_return_val_if_fail (GTK_IS_GESTURE (gesture), FALSE);
priv = gtk_gesture_get_instance_private (gesture);
g_hash_table_iter_init (&iter, priv->points);
while (g_hash_table_iter_next (&iter, (gpointer*) &seq, (gpointer*) &data))
{
switch ((guint) gdk_event_get_event_type (data->event))
{
case GDK_TOUCH_BEGIN:
case GDK_TOUCH_UPDATE:
case GDK_TOUCH_END:
if (!gdk_touch_event_get_emulating_pointer (data->event))
continue;
G_GNUC_FALLTHROUGH;
case GDK_BUTTON_PRESS:
case GDK_BUTTON_RELEASE:
case GDK_MOTION_NOTIFY:
*sequence = seq;
return TRUE;
default:
break;
}
}
return FALSE;
}