From a9fa0151f1c30f77134e31ac260afa17aa3b273f Mon Sep 17 00:00:00 2001 From: Carlos Garnacho Date: Mon, 3 Mar 2014 14:08:45 +0100 Subject: [PATCH] widget: Implement hierarchy-level mechanism to claim/deny sequences The policy of sequence states has been made tighter on GtkGesture, so gestures can never return to a "none" state, nor get out of a "denied" state, a "claimed" sequence can go "denied" though. The helper API at the widget level will first emit GtkWidget::sequence-state-changed on the called widget, and then notify through the same signal to every other widget in the captured event chain. So the effect of that signal is twofold, on one hand it lets the original widget set the state on its attached controllers, and on the other hand it lets the other widgets freely adapt to the sequence state changing elsewhere in the event widget chain. By default, that signal updates every controller on the first usecase, and propagates the default gesture policy to every other widget in the chain on the second. This means that, by default: 1) Sequences start out on the "none" state, and get propagated through all the event widget chain. 2) If a widget in the chain denies the sequence, all other widgets are unaffected. 3) If a widget in the chain claims the sequence, then: 3.1) Every widget below the claiming widget (ie. towards the event widget) will get the sequence cancelled. 3.2) Every widget above the claiming widget that had the sequence as "none" will remain as such, if it was claimed it will go denied, but that should rarely happen. This behavior can be tweaked through the GtkWidget::sequence-state-changed and GtkGesture::event-handled vmethods, although this should be very rarely done. --- gtk/gtkgesture.c | 63 +++++++++++++++++++++++- gtk/gtkgesture.h | 7 ++- gtk/gtkwidget.c | 126 +++++++++++++++++++++++++++++++++++++++++------ 3 files changed, 177 insertions(+), 19 deletions(-) diff --git a/gtk/gtkgesture.c b/gtk/gtkgesture.c index 27cc1f5670..e86e6d4f0b 100644 --- a/gtk/gtkgesture.c +++ b/gtk/gtkgesture.c @@ -37,6 +37,7 @@ enum { BEGIN, END, UPDATE, + CANCEL, SEQUENCE_STATE_CHANGED, N_SIGNALS }; @@ -403,6 +404,13 @@ gtk_gesture_class_init (GtkGestureClass *klass) G_STRUCT_OFFSET (GtkGestureClass, update), NULL, NULL, NULL, G_TYPE_NONE, 1, G_TYPE_POINTER); + signals[CANCEL] = + g_signal_new ("cancel", + G_TYPE_FROM_CLASS (klass), + G_SIGNAL_RUN_LAST, + G_STRUCT_OFFSET (GtkGestureClass, cancel), + NULL, NULL, NULL, + G_TYPE_NONE, 1, G_TYPE_POINTER); signals[SEQUENCE_STATE_CHANGED] = g_signal_new ("sequence-state-changed", G_TYPE_FROM_CLASS (klass), @@ -505,9 +513,20 @@ gtk_gesture_get_sequence_state (GtkGesture *gesture, * @sequence: a #GdkEventSequence * @state: the sequence state * - * Sets the state of @sequence in @gesture. + * 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: * - * Returns: #TRUE if @sequence is handled by @gesture. + * * None + * * None → Denied + * * None → Claimed + * * None → Claimed → Denied + * + * Returns: #TRUE if @sequence is handled by @gesture, + * and the state is changed successfully. * * Since: 3.14 **/ @@ -530,6 +549,15 @@ gtk_gesture_set_sequence_state (GtkGesture *gesture, if (!data || 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; + old_state = data->state; data->state = state; g_signal_emit (gesture, signals[SEQUENCE_STATE_CHANGED], 0, @@ -962,3 +990,34 @@ gtk_gesture_handles_sequence (GtkGesture *gesture, return g_hash_table_contains (priv->points, sequence); } + +/** + * gtk_gesture_cancel_sequence: + * @gesture: a #GtkGesture + * @sequence: a #GdkEventSequence + * + * Cancels @sequence on @gesture, this emits #GtkGesture::cancel + * and forgets the sequence altogether. + * + * Returns: #TRUE if the sequence was being handled by gesture + **/ +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_check_recognized (gesture, sequence); + _gtk_gesture_remove_point (gesture, data->event); + return TRUE; +} diff --git a/gtk/gtkgesture.h b/gtk/gtkgesture.h index a9296c73fa..1d28000987 100644 --- a/gtk/gtkgesture.h +++ b/gtk/gtkgesture.h @@ -57,6 +57,9 @@ struct _GtkGestureClass void (* end) (GtkGesture *gesture, GdkEventSequence *sequence); + void (* cancel) (GtkGesture *gesture, + GdkEventSequence *sequence); + void (* sequence_state_changed) (GtkGesture *gesture, GdkEventSequence *sequence, GtkEventSequenceState state); @@ -89,7 +92,9 @@ GdkEventSequence * gtk_gesture_get_last_updated_sequence GDK_AVAILABLE_IN_3_14 gboolean gtk_gesture_handles_sequence (GtkGesture *gesture, GdkEventSequence *sequence); - +GDK_AVAILABLE_IN_3_14 +gboolean gtk_gesture_cancel_sequence (GtkGesture *gesture, + GdkEventSequence *sequence); GDK_AVAILABLE_IN_3_14 const GdkEvent * gtk_gesture_get_last_event (GtkGesture *gesture, diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c index b10f4ac619..13cbf3bb1c 100644 --- a/gtk/gtkwidget.c +++ b/gtk/gtkwidget.c @@ -592,6 +592,7 @@ enum { DRAG_FAILED, STYLE_UPDATED, TOUCH_EVENT, + SEQUENCE_STATE_CHANGED, LAST_SIGNAL }; @@ -3427,6 +3428,14 @@ G_GNUC_END_IGNORE_DEPRECATIONS _gtk_marshal_BOOLEAN__UINT, G_TYPE_BOOLEAN, 1, G_TYPE_UINT); + widget_signals[SEQUENCE_STATE_CHANGED] = + g_signal_new (I_("sequence-state-changed"), + G_TYPE_FROM_CLASS (klass), + G_SIGNAL_RUN_LAST, 0, + g_signal_accumulator_first_wins, NULL, NULL, + G_TYPE_BOOLEAN, 3, GTK_TYPE_WIDGET, + G_TYPE_POINTER, GTK_TYPE_EVENT_SEQUENCE_STATE); + binding_set = gtk_binding_set_by_class (klass); gtk_binding_entry_add_signal (binding_set, GDK_KEY_F10, GDK_SHIFT_MASK, "popup-menu", 0); @@ -4035,6 +4044,78 @@ gtk_widget_get_property (GObject *object, } } +static gboolean +_gtk_widget_set_sequence_state_internal (GtkWidget *widget, + GdkEventSequence *sequence, + GtkEventSequenceState state) +{ + GtkWidgetPrivate *priv = widget->priv; + EventControllerData *data; + gboolean handled = FALSE; + GList *l; + + for (l = priv->event_controllers; l; l = l->next) + { + data = l->data; + + if (!GTK_IS_GESTURE (data->controller)) + continue; + + handled |= gtk_gesture_set_sequence_state (GTK_GESTURE (data->controller), + sequence, state); + } + + return handled; +} + +static gboolean +_gtk_widget_cancel_sequence (GtkWidget *widget, + GdkEventSequence *sequence) +{ + GtkWidgetPrivate *priv = widget->priv; + EventControllerData *data; + gboolean handled = FALSE; + GList *l; + + for (l = priv->event_controllers; l; l = l->next) + { + data = l->data; + + if (!GTK_IS_GESTURE (data->controller)) + continue; + + handled |= gtk_gesture_cancel_sequence (GTK_GESTURE (data->controller), + sequence); + } + + return handled; +} + +static gboolean +gtk_widget_real_sequence_state_changed (GtkWidget *widget, + GtkWidget *changed_widget, + GdkEventSequence *sequence, + GtkEventSequenceState state) +{ + GtkEventSequenceState changed_state; + + if (widget == changed_widget) + return _gtk_widget_set_sequence_state_internal (widget, sequence, state); + else if (gtk_widget_is_ancestor (widget, changed_widget)) + return _gtk_widget_cancel_sequence (widget, sequence); + else + { + changed_state = gtk_widget_get_sequence_state (changed_widget, sequence); + + if (state == GTK_EVENT_SEQUENCE_CLAIMED && + changed_state == GTK_EVENT_SEQUENCE_CLAIMED) + return _gtk_widget_set_sequence_state_internal (widget, sequence, + GTK_EVENT_SEQUENCE_DENIED); + } + + return FALSE; +} + static void gtk_widget_init (GtkWidget *widget) { @@ -4092,6 +4173,10 @@ gtk_widget_init (GtkWidget *widget) priv->style = gtk_widget_get_default_style (); G_GNUC_END_IGNORE_DEPRECATIONS; g_object_ref (priv->style); + + g_signal_connect (widget, "sequence-state-changed", + G_CALLBACK (gtk_widget_real_sequence_state_changed), + NULL); } @@ -16487,27 +16572,36 @@ gtk_widget_set_sequence_state (GtkWidget *widget, { EventControllerData *data; gboolean handled = FALSE; + GtkWidget *event_widget; GtkWidgetPrivate *priv; - GList *l; + const GdkEvent *event; - g_return_val_if_fail (GTK_IS_WIDGET (widget), - GTK_EVENT_SEQUENCE_NONE); + g_return_if_fail (GTK_IS_WIDGET (widget)); + g_return_if_fail (state >= GTK_EVENT_SEQUENCE_NONE && + state <= GTK_EVENT_SEQUENCE_DENIED); - priv = widget->priv; - - for (l = priv->event_controllers; l; l = l->next) - { - data = l->data; - - if (!GTK_IS_GESTURE (data->controller)) - continue; - - handled |= gtk_gesture_set_sequence_state (GTK_GESTURE (data->controller), - sequence, state); - } + g_signal_emit (widget, widget_signals[SEQUENCE_STATE_CHANGED], + 0, widget, sequence, state, &handled); if (!handled) return; - /* FIXME: Propagate upwards/downwards */ + priv = widget->priv; + data = priv->event_controllers->data; + event = gtk_gesture_get_last_event (GTK_GESTURE (data->controller), sequence); + + if (!event) + return; + + event_widget = gtk_get_event_widget ((GdkEvent *) event); + g_assert (widget == event_widget || + gtk_widget_is_ancestor (event_widget, widget)); + + while (event_widget) + { + if (event_widget != widget) + g_signal_emit (event_widget, widget_signals[SEQUENCE_STATE_CHANGED], + 0, widget, sequence, state, &handled); + event_widget = gtk_widget_get_parent (event_widget); + } }