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/* Constraints/Interactive
*
* Demonstrate how constraints can be updates during
* user interaction.
*/
#include <glib/gi18n.h>
#include <gtk/gtk.h>
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_destroy (GtkWidget *widget)
{
InteractiveGrid *self = INTERACTIVE_GRID (widget);
g_clear_pointer (&self->button1, gtk_widget_destroy);
g_clear_pointer (&self->button2, gtk_widget_destroy);
g_clear_pointer (&self->button3, gtk_widget_destroy);
GTK_WIDGET_CLASS (interactive_grid_parent_class)->destroy (widget);
}
static void
interactive_grid_class_init (InteractiveGridClass *klass)
{
GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
widget_class->destroy = interactive_grid_destroy;
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_constraints2 (GtkWidget *do_widget)
{
static GtkWidget *window;
if (!window)
{
GtkWidget *header, *box, *grid, *button;
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
gtk_window_set_display (GTK_WINDOW (window), gtk_widget_get_display (do_widget));
header = gtk_header_bar_new ();
gtk_header_bar_set_title (GTK_HEADER_BAR (header), "Constraints");
gtk_header_bar_set_show_title_buttons (GTK_HEADER_BAR (header), FALSE);
gtk_window_set_titlebar (GTK_WINDOW (window), header);
g_signal_connect (window, "destroy",
G_CALLBACK (gtk_widget_destroyed), &window);
box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 12);
gtk_container_add (GTK_CONTAINER (window), box);
grid = g_object_new (interactive_grid_get_type (), NULL);
gtk_widget_set_hexpand (grid, TRUE);
gtk_widget_set_vexpand (grid, TRUE);
gtk_container_add (GTK_CONTAINER (box), grid);
button = gtk_button_new_with_label ("Close");
gtk_container_add (GTK_CONTAINER (box), button);
gtk_widget_set_hexpand (grid, TRUE);
g_signal_connect_swapped (button, "clicked",
G_CALLBACK (gtk_widget_destroy), window);
}
if (!gtk_widget_get_visible (window))
gtk_widget_show (window);
else
gtk_widget_destroy (window);
return window;
}
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