/* Constraints/Interactive Constraints * #Keywords: GtkConstraintLayout * * This example shows how constraints can be updated during user interaction. * The vertical edge between the buttons can be dragged with the mouse. */ #include #include G_DECLARE_FINAL_TYPE (InteractiveGrid, interactive_grid, INTERACTIVE, GRID, GtkWidget) struct _InteractiveGrid { GtkWidget parent_instance; GtkWidget *button1, *button2; GtkWidget *button3; GtkConstraintGuide *guide; GtkConstraint *constraint; }; G_DEFINE_TYPE (InteractiveGrid, interactive_grid, GTK_TYPE_WIDGET) static void interactive_grid_dispose (GObject *object) { InteractiveGrid *self = INTERACTIVE_GRID (object); g_clear_pointer (&self->button1, gtk_widget_unparent); g_clear_pointer (&self->button2, gtk_widget_unparent); g_clear_pointer (&self->button3, gtk_widget_unparent); G_OBJECT_CLASS (interactive_grid_parent_class)->dispose (object); } static void interactive_grid_class_init (InteractiveGridClass *klass) { GObjectClass *object_class = G_OBJECT_CLASS (klass); GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass); object_class->dispose = interactive_grid_dispose; gtk_widget_class_set_layout_manager_type (widget_class, GTK_TYPE_CONSTRAINT_LAYOUT); } static void build_constraints (InteractiveGrid *self, GtkConstraintLayout *manager) { self->guide = g_object_new (GTK_TYPE_CONSTRAINT_GUIDE, NULL); gtk_constraint_layout_add_guide (manager, self->guide); gtk_constraint_layout_add_constraint (manager, gtk_constraint_new_constant (GTK_CONSTRAINT_TARGET (self->guide), GTK_CONSTRAINT_ATTRIBUTE_WIDTH, GTK_CONSTRAINT_RELATION_EQ, 0.0, GTK_CONSTRAINT_STRENGTH_REQUIRED)); gtk_constraint_layout_add_constraint (manager, gtk_constraint_new (NULL, GTK_CONSTRAINT_ATTRIBUTE_START, GTK_CONSTRAINT_RELATION_EQ, GTK_CONSTRAINT_TARGET (self->button1), GTK_CONSTRAINT_ATTRIBUTE_START, 1.0, -8.0, GTK_CONSTRAINT_STRENGTH_REQUIRED)); gtk_constraint_layout_add_constraint (manager, gtk_constraint_new (GTK_CONSTRAINT_TARGET (self->button1), GTK_CONSTRAINT_ATTRIBUTE_END, GTK_CONSTRAINT_RELATION_EQ, GTK_CONSTRAINT_TARGET (self->guide), GTK_CONSTRAINT_ATTRIBUTE_START, 1.0, 0.0, GTK_CONSTRAINT_STRENGTH_REQUIRED)); gtk_constraint_layout_add_constraint (manager, gtk_constraint_new (GTK_CONSTRAINT_TARGET (self->button2), GTK_CONSTRAINT_ATTRIBUTE_START, GTK_CONSTRAINT_RELATION_EQ, GTK_CONSTRAINT_TARGET (self->guide), GTK_CONSTRAINT_ATTRIBUTE_END, 1.0, 0.0, GTK_CONSTRAINT_STRENGTH_REQUIRED)); gtk_constraint_layout_add_constraint (manager, gtk_constraint_new (GTK_CONSTRAINT_TARGET (self->button2), GTK_CONSTRAINT_ATTRIBUTE_END, GTK_CONSTRAINT_RELATION_EQ, NULL, GTK_CONSTRAINT_ATTRIBUTE_END, 1.0, -8.0, GTK_CONSTRAINT_STRENGTH_REQUIRED)); gtk_constraint_layout_add_constraint (manager, gtk_constraint_new (NULL, GTK_CONSTRAINT_ATTRIBUTE_START, GTK_CONSTRAINT_RELATION_EQ, GTK_CONSTRAINT_TARGET (self->button3), GTK_CONSTRAINT_ATTRIBUTE_START, 1.0, -8.0, GTK_CONSTRAINT_STRENGTH_REQUIRED)); gtk_constraint_layout_add_constraint (manager, gtk_constraint_new (GTK_CONSTRAINT_TARGET (self->button3), GTK_CONSTRAINT_ATTRIBUTE_END, GTK_CONSTRAINT_RELATION_EQ, GTK_CONSTRAINT_TARGET (self->guide), GTK_CONSTRAINT_ATTRIBUTE_START, 1.0, 0.0, GTK_CONSTRAINT_STRENGTH_REQUIRED)); gtk_constraint_layout_add_constraint (manager, gtk_constraint_new (NULL, GTK_CONSTRAINT_ATTRIBUTE_TOP, GTK_CONSTRAINT_RELATION_EQ, GTK_CONSTRAINT_TARGET (self->button1), GTK_CONSTRAINT_ATTRIBUTE_TOP, 1.0, -8.0, GTK_CONSTRAINT_STRENGTH_REQUIRED)); gtk_constraint_layout_add_constraint (manager, gtk_constraint_new (GTK_CONSTRAINT_TARGET (self->button2), GTK_CONSTRAINT_ATTRIBUTE_TOP, GTK_CONSTRAINT_RELATION_EQ, GTK_CONSTRAINT_TARGET (self->button1), GTK_CONSTRAINT_ATTRIBUTE_BOTTOM, 1.0, 0.0, GTK_CONSTRAINT_STRENGTH_REQUIRED)); gtk_constraint_layout_add_constraint (manager, gtk_constraint_new (GTK_CONSTRAINT_TARGET (self->button3), GTK_CONSTRAINT_ATTRIBUTE_TOP, GTK_CONSTRAINT_RELATION_EQ, GTK_CONSTRAINT_TARGET (self->button2), GTK_CONSTRAINT_ATTRIBUTE_BOTTOM, 1.0, 0.0, GTK_CONSTRAINT_STRENGTH_REQUIRED)); gtk_constraint_layout_add_constraint (manager, gtk_constraint_new (GTK_CONSTRAINT_TARGET (self->button3), GTK_CONSTRAINT_ATTRIBUTE_BOTTOM, GTK_CONSTRAINT_RELATION_EQ, NULL, GTK_CONSTRAINT_ATTRIBUTE_BOTTOM, 1.0, -8.0, GTK_CONSTRAINT_STRENGTH_REQUIRED)); } static void drag_cb (GtkGestureDrag *drag, double offset_x, double offset_y, InteractiveGrid *self) { GtkConstraintLayout *layout = GTK_CONSTRAINT_LAYOUT (gtk_widget_get_layout_manager (GTK_WIDGET (self))); double x, y; if (self->constraint) { gtk_constraint_layout_remove_constraint (layout, self->constraint); g_clear_object (&self->constraint); } gtk_gesture_drag_get_start_point (drag, &x, &y); self->constraint = gtk_constraint_new_constant (GTK_CONSTRAINT_TARGET (self->guide), GTK_CONSTRAINT_ATTRIBUTE_LEFT, GTK_CONSTRAINT_RELATION_EQ, x + offset_x, GTK_CONSTRAINT_STRENGTH_REQUIRED); gtk_constraint_layout_add_constraint (layout, g_object_ref (self->constraint)); gtk_widget_queue_allocate (GTK_WIDGET (self)); } static void interactive_grid_init (InteractiveGrid *self) { GtkWidget *widget = GTK_WIDGET (self); GtkGesture *drag; self->button1 = gtk_button_new_with_label ("Child 1"); gtk_widget_set_parent (self->button1, widget); gtk_widget_set_name (self->button1, "button1"); self->button2 = gtk_button_new_with_label ("Child 2"); gtk_widget_set_parent (self->button2, widget); gtk_widget_set_name (self->button2, "button2"); self->button3 = gtk_button_new_with_label ("Child 3"); gtk_widget_set_parent (self->button3, widget); gtk_widget_set_name (self->button3, "button3"); GtkLayoutManager *manager = gtk_widget_get_layout_manager (GTK_WIDGET (self)); build_constraints (self, GTK_CONSTRAINT_LAYOUT (manager)); drag = gtk_gesture_drag_new (); g_signal_connect (drag, "drag-update", G_CALLBACK (drag_cb), self); gtk_widget_add_controller (GTK_WIDGET (self), GTK_EVENT_CONTROLLER (drag)); } GtkWidget * do_constraints_interactive (GtkWidget *do_widget) { static GtkWidget *window; if (!window) { GtkWidget *box, *grid; window = gtk_window_new (); gtk_window_set_display (GTK_WINDOW (window), gtk_widget_get_display (do_widget)); gtk_window_set_title (GTK_WINDOW (window), "Interactive Constraints"); gtk_window_set_default_size (GTK_WINDOW (window), 260, -1); g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window); box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 12); gtk_window_set_child (GTK_WINDOW (window), box); grid = g_object_new (interactive_grid_get_type (), NULL); gtk_widget_set_hexpand (grid, TRUE); gtk_widget_set_vexpand (grid, TRUE); gtk_box_append (GTK_BOX (box), grid); } if (!gtk_widget_get_visible (window)) gtk_widget_show (window); else gtk_window_destroy (GTK_WINDOW (window)); return window; }