238 lines
8.9 KiB
C
238 lines
8.9 KiB
C
/* Constraints/Interactive Constraints
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* #Keywords: GtkConstraintLayout
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*
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* This example shows how constraints can be updated during user interaction.
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* The vertical edge between the buttons can be dragged with the mouse.
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*/
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#include <glib/gi18n.h>
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#include <gtk/gtk.h>
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G_DECLARE_FINAL_TYPE (InteractiveGrid, interactive_grid, INTERACTIVE, GRID, GtkWidget)
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struct _InteractiveGrid
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{
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GtkWidget parent_instance;
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GtkWidget *button1, *button2;
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GtkWidget *button3;
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GtkConstraintGuide *guide;
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GtkConstraint *constraint;
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};
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G_DEFINE_TYPE (InteractiveGrid, interactive_grid, GTK_TYPE_WIDGET)
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static void
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interactive_grid_dispose (GObject *object)
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{
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InteractiveGrid *self = INTERACTIVE_GRID (object);
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g_clear_pointer (&self->button1, gtk_widget_unparent);
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g_clear_pointer (&self->button2, gtk_widget_unparent);
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g_clear_pointer (&self->button3, gtk_widget_unparent);
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G_OBJECT_CLASS (interactive_grid_parent_class)->dispose (object);
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}
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static void
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interactive_grid_class_init (InteractiveGridClass *klass)
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{
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GObjectClass *object_class = G_OBJECT_CLASS (klass);
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GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
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object_class->dispose = interactive_grid_dispose;
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gtk_widget_class_set_layout_manager_type (widget_class, GTK_TYPE_CONSTRAINT_LAYOUT);
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}
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static void
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build_constraints (InteractiveGrid *self,
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GtkConstraintLayout *manager)
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{
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self->guide = g_object_new (GTK_TYPE_CONSTRAINT_GUIDE, NULL);
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gtk_constraint_layout_add_guide (manager, self->guide);
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gtk_constraint_layout_add_constraint (manager,
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gtk_constraint_new_constant (GTK_CONSTRAINT_TARGET (self->guide),
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GTK_CONSTRAINT_ATTRIBUTE_WIDTH,
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GTK_CONSTRAINT_RELATION_EQ,
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0.0,
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GTK_CONSTRAINT_STRENGTH_REQUIRED));
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gtk_constraint_layout_add_constraint (manager,
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gtk_constraint_new (NULL,
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GTK_CONSTRAINT_ATTRIBUTE_START,
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GTK_CONSTRAINT_RELATION_EQ,
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GTK_CONSTRAINT_TARGET (self->button1),
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GTK_CONSTRAINT_ATTRIBUTE_START,
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1.0,
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-8.0,
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GTK_CONSTRAINT_STRENGTH_REQUIRED));
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gtk_constraint_layout_add_constraint (manager,
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gtk_constraint_new (GTK_CONSTRAINT_TARGET (self->button1),
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GTK_CONSTRAINT_ATTRIBUTE_END,
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GTK_CONSTRAINT_RELATION_EQ,
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GTK_CONSTRAINT_TARGET (self->guide),
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GTK_CONSTRAINT_ATTRIBUTE_START,
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1.0,
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0.0,
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GTK_CONSTRAINT_STRENGTH_REQUIRED));
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gtk_constraint_layout_add_constraint (manager,
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gtk_constraint_new (GTK_CONSTRAINT_TARGET (self->button2),
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GTK_CONSTRAINT_ATTRIBUTE_START,
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GTK_CONSTRAINT_RELATION_EQ,
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GTK_CONSTRAINT_TARGET (self->guide),
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GTK_CONSTRAINT_ATTRIBUTE_END,
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1.0,
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0.0,
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GTK_CONSTRAINT_STRENGTH_REQUIRED));
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gtk_constraint_layout_add_constraint (manager,
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gtk_constraint_new (GTK_CONSTRAINT_TARGET (self->button2),
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GTK_CONSTRAINT_ATTRIBUTE_END,
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GTK_CONSTRAINT_RELATION_EQ,
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NULL,
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GTK_CONSTRAINT_ATTRIBUTE_END,
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1.0,
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-8.0,
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GTK_CONSTRAINT_STRENGTH_REQUIRED));
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gtk_constraint_layout_add_constraint (manager,
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gtk_constraint_new (NULL,
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GTK_CONSTRAINT_ATTRIBUTE_START,
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GTK_CONSTRAINT_RELATION_EQ,
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GTK_CONSTRAINT_TARGET (self->button3),
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GTK_CONSTRAINT_ATTRIBUTE_START,
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1.0,
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-8.0,
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GTK_CONSTRAINT_STRENGTH_REQUIRED));
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gtk_constraint_layout_add_constraint (manager,
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gtk_constraint_new (GTK_CONSTRAINT_TARGET (self->button3),
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GTK_CONSTRAINT_ATTRIBUTE_END,
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GTK_CONSTRAINT_RELATION_EQ,
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GTK_CONSTRAINT_TARGET (self->guide),
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GTK_CONSTRAINT_ATTRIBUTE_START,
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1.0,
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0.0,
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GTK_CONSTRAINT_STRENGTH_REQUIRED));
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gtk_constraint_layout_add_constraint (manager,
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gtk_constraint_new (NULL,
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GTK_CONSTRAINT_ATTRIBUTE_TOP,
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GTK_CONSTRAINT_RELATION_EQ,
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GTK_CONSTRAINT_TARGET (self->button1),
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GTK_CONSTRAINT_ATTRIBUTE_TOP,
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1.0,
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-8.0,
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GTK_CONSTRAINT_STRENGTH_REQUIRED));
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gtk_constraint_layout_add_constraint (manager,
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gtk_constraint_new (GTK_CONSTRAINT_TARGET (self->button2),
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GTK_CONSTRAINT_ATTRIBUTE_TOP,
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GTK_CONSTRAINT_RELATION_EQ,
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GTK_CONSTRAINT_TARGET (self->button1),
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GTK_CONSTRAINT_ATTRIBUTE_BOTTOM,
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1.0,
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0.0,
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GTK_CONSTRAINT_STRENGTH_REQUIRED));
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gtk_constraint_layout_add_constraint (manager,
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gtk_constraint_new (GTK_CONSTRAINT_TARGET (self->button3),
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GTK_CONSTRAINT_ATTRIBUTE_TOP,
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GTK_CONSTRAINT_RELATION_EQ,
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GTK_CONSTRAINT_TARGET (self->button2),
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GTK_CONSTRAINT_ATTRIBUTE_BOTTOM,
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1.0,
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0.0,
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GTK_CONSTRAINT_STRENGTH_REQUIRED));
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gtk_constraint_layout_add_constraint (manager,
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gtk_constraint_new (GTK_CONSTRAINT_TARGET (self->button3),
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GTK_CONSTRAINT_ATTRIBUTE_BOTTOM,
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GTK_CONSTRAINT_RELATION_EQ,
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NULL,
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GTK_CONSTRAINT_ATTRIBUTE_BOTTOM,
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1.0,
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-8.0,
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GTK_CONSTRAINT_STRENGTH_REQUIRED));
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}
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static void
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drag_cb (GtkGestureDrag *drag,
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double offset_x,
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double offset_y,
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InteractiveGrid *self)
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{
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GtkConstraintLayout *layout = GTK_CONSTRAINT_LAYOUT (gtk_widget_get_layout_manager (GTK_WIDGET (self)));
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double x, y;
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if (self->constraint)
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{
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gtk_constraint_layout_remove_constraint (layout, self->constraint);
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g_clear_object (&self->constraint);
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}
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gtk_gesture_drag_get_start_point (drag, &x, &y);
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self->constraint = gtk_constraint_new_constant (GTK_CONSTRAINT_TARGET (self->guide),
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GTK_CONSTRAINT_ATTRIBUTE_LEFT,
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GTK_CONSTRAINT_RELATION_EQ,
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x + offset_x,
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GTK_CONSTRAINT_STRENGTH_REQUIRED);
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gtk_constraint_layout_add_constraint (layout, g_object_ref (self->constraint));
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gtk_widget_queue_allocate (GTK_WIDGET (self));
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}
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static void
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interactive_grid_init (InteractiveGrid *self)
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{
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GtkWidget *widget = GTK_WIDGET (self);
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GtkGesture *drag;
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self->button1 = gtk_button_new_with_label ("Child 1");
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gtk_widget_set_parent (self->button1, widget);
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gtk_widget_set_name (self->button1, "button1");
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self->button2 = gtk_button_new_with_label ("Child 2");
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gtk_widget_set_parent (self->button2, widget);
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gtk_widget_set_name (self->button2, "button2");
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self->button3 = gtk_button_new_with_label ("Child 3");
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gtk_widget_set_parent (self->button3, widget);
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gtk_widget_set_name (self->button3, "button3");
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GtkLayoutManager *manager = gtk_widget_get_layout_manager (GTK_WIDGET (self));
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build_constraints (self, GTK_CONSTRAINT_LAYOUT (manager));
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drag = gtk_gesture_drag_new ();
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g_signal_connect (drag, "drag-update", G_CALLBACK (drag_cb), self);
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gtk_widget_add_controller (GTK_WIDGET (self), GTK_EVENT_CONTROLLER (drag));
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}
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GtkWidget *
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do_constraints_interactive (GtkWidget *do_widget)
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{
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static GtkWidget *window;
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if (!window)
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{
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GtkWidget *box, *grid;
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window = gtk_window_new ();
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gtk_window_set_display (GTK_WINDOW (window), gtk_widget_get_display (do_widget));
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gtk_window_set_title (GTK_WINDOW (window), "Interactive Constraints");
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gtk_window_set_default_size (GTK_WINDOW (window), 260, -1);
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g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
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box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 12);
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gtk_window_set_child (GTK_WINDOW (window), box);
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grid = g_object_new (interactive_grid_get_type (), NULL);
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gtk_widget_set_hexpand (grid, TRUE);
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gtk_widget_set_vexpand (grid, TRUE);
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gtk_box_append (GTK_BOX (box), grid);
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}
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if (!gtk_widget_get_visible (window))
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gtk_widget_set_visible (window, TRUE);
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else
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gtk_window_destroy (GTK_WINDOW (window));
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return window;
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}
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