gtk2/demos/constraint-editor/constraint-view.c
Benjamin Otte 5080730728 listmodels: Stop respecting item-type
Simplify all view model APIs and always return G_TYPE_OBJECT as the
item-type for every model.

It turns out nobody uses item-type anyway.

So instead of adding lots of APIs, forcing people to think about it and
trying to figure out how to handle filter or map models that modify item
types, just having an easy life is a better approach.

All the models need to be able to deal with any type of object going
through anyway.
2020-07-05 02:59:21 +02:00

349 lines
11 KiB
C

/* Copyright (C) 2019 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/>.
*/
#include <gtk/gtk.h>
#include "constraint-view.h"
struct _ConstraintView
{
GtkWidget parent;
GListModel *model;
GtkWidget *drag_widget;
};
G_DEFINE_TYPE (ConstraintView, constraint_view, GTK_TYPE_WIDGET);
static void
constraint_view_dispose (GObject *object)
{
ConstraintView *view = CONSTRAINT_VIEW (object);
GtkWidget *child;
while ((child = gtk_widget_get_first_child (GTK_WIDGET (view))) != NULL)
gtk_widget_unparent (child);
g_clear_object (&view->model);
G_OBJECT_CLASS (constraint_view_parent_class)->dispose (object);
}
static void
constraint_view_class_init (ConstraintViewClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
object_class->dispose = constraint_view_dispose;
gtk_widget_class_set_css_name (widget_class, "constraintview");
}
static void
update_weak_position (ConstraintView *self,
GtkWidget *child,
double x,
double y)
{
GtkLayoutManager *manager;
GtkConstraint *constraint;
manager = gtk_widget_get_layout_manager (GTK_WIDGET (self));
constraint = (GtkConstraint *)g_object_get_data (G_OBJECT (child), "x-constraint");
if (constraint)
{
gtk_constraint_layout_remove_constraint (GTK_CONSTRAINT_LAYOUT (manager),
constraint);
g_object_set_data (G_OBJECT (child), "x-constraint", NULL);
}
if (x != -100)
{
constraint = gtk_constraint_new_constant (child,
GTK_CONSTRAINT_ATTRIBUTE_CENTER_X,
GTK_CONSTRAINT_RELATION_EQ,
x,
GTK_CONSTRAINT_STRENGTH_WEAK);
g_object_set_data (G_OBJECT (constraint), "internal", (char *)"yes");
gtk_constraint_layout_add_constraint (GTK_CONSTRAINT_LAYOUT (manager),
constraint);
g_object_set_data (G_OBJECT (child), "x-constraint", constraint);
}
constraint = (GtkConstraint *)g_object_get_data (G_OBJECT (child), "y-constraint");
if (constraint)
{
gtk_constraint_layout_remove_constraint (GTK_CONSTRAINT_LAYOUT (manager),
constraint);
g_object_set_data (G_OBJECT (child), "y-constraint", NULL);
}
if (y != -100)
{
constraint = gtk_constraint_new_constant (child,
GTK_CONSTRAINT_ATTRIBUTE_CENTER_Y,
GTK_CONSTRAINT_RELATION_EQ,
y,
GTK_CONSTRAINT_STRENGTH_WEAK);
g_object_set_data (G_OBJECT (constraint), "internal", (char *)"yes");
gtk_constraint_layout_add_constraint (GTK_CONSTRAINT_LAYOUT (manager),
constraint);
g_object_set_data (G_OBJECT (child), "y-constraint", constraint);
}
}
static void
drag_begin (GtkGestureDrag *drag,
double start_x,
double start_y,
ConstraintView *self)
{
GtkWidget *widget;
widget = gtk_widget_pick (GTK_WIDGET (self), start_x, start_y, GTK_PICK_DEFAULT);
if (GTK_IS_LABEL (widget))
{
widget = gtk_widget_get_ancestor (widget, GTK_TYPE_FRAME);
if (widget &&
gtk_widget_get_parent (widget) == (GtkWidget *)self)
{
self->drag_widget = widget;
}
}
}
static void
drag_update (GtkGestureDrag *drag,
double offset_x,
double offset_y,
ConstraintView *self)
{
double x, y;
if (!self->drag_widget)
return;
gtk_gesture_drag_get_start_point (drag, &x, &y);
update_weak_position (self, self->drag_widget, x + offset_x, y + offset_y);
}
static void
drag_end (GtkGestureDrag *drag,
double offset_x,
double offset_y,
ConstraintView *self)
{
self->drag_widget = NULL;
}
static gboolean
omit_internal (gpointer item, gpointer user_data)
{
if (g_object_get_data (G_OBJECT (item), "internal"))
return FALSE;
return TRUE;
}
static void
constraint_view_init (ConstraintView *self)
{
GtkLayoutManager *manager;
GtkEventController *controller;
GListStore *list;
GListModel *all_children;
GListModel *all_constraints;
GListModel *guides;
GListModel *children;
GListModel *constraints;
GtkFilter *filter;
manager = gtk_constraint_layout_new ();
gtk_widget_set_layout_manager (GTK_WIDGET (self), manager);
all_children = gtk_widget_observe_children (GTK_WIDGET (self));
all_constraints = gtk_constraint_layout_observe_constraints (GTK_CONSTRAINT_LAYOUT (manager));
guides = gtk_constraint_layout_observe_guides (GTK_CONSTRAINT_LAYOUT (manager));
filter = gtk_custom_filter_new (omit_internal, NULL, NULL);
constraints = (GListModel *)gtk_filter_list_model_new (all_constraints, filter);
g_object_unref (filter);
filter = gtk_custom_filter_new (omit_internal, NULL, NULL);
children = (GListModel *)gtk_filter_list_model_new (all_children, filter);
g_object_unref (filter);
list = g_list_store_new (G_TYPE_LIST_MODEL);
g_list_store_append (list, children);
g_list_store_append (list, guides);
g_list_store_append (list, constraints);
self->model = G_LIST_MODEL (gtk_flatten_list_model_new (G_LIST_MODEL (list)));
g_object_unref (children);
g_object_unref (guides);
g_object_unref (constraints);
g_object_unref (all_children);
g_object_unref (all_constraints);
g_object_unref (list);
controller = (GtkEventController *)gtk_gesture_drag_new ();
g_signal_connect (controller, "drag-begin", G_CALLBACK (drag_begin), self);
g_signal_connect (controller, "drag-update", G_CALLBACK (drag_update), self);
g_signal_connect (controller, "drag-end", G_CALLBACK (drag_end), self);
gtk_widget_add_controller (GTK_WIDGET (self), controller);
}
ConstraintView *
constraint_view_new (void)
{
return g_object_new (CONSTRAINT_VIEW_TYPE, NULL);
}
void
constraint_view_add_child (ConstraintView *view,
const char *name)
{
GtkWidget *frame;
GtkWidget *label;
label = gtk_label_new (name);
frame = gtk_frame_new (NULL);
gtk_widget_add_css_class (frame, "child");
gtk_widget_set_name (frame, name);
gtk_frame_set_child (GTK_FRAME (frame), label);
gtk_widget_set_parent (frame, GTK_WIDGET (view));
update_weak_position (view, frame, 100, 100);
}
void
constraint_view_remove_child (ConstraintView *view,
GtkWidget *child)
{
update_weak_position (view, child, -100, -100);
gtk_widget_unparent (child);
}
void
constraint_view_add_guide (ConstraintView *view,
GtkConstraintGuide *guide)
{
GtkConstraintLayout *layout;
GtkWidget *frame;
GtkWidget *label;
const char *name;
GtkConstraint *constraint;
struct {
const char *name;
GtkConstraintAttribute attr;
} names[] = {
{ "left-constraint", GTK_CONSTRAINT_ATTRIBUTE_LEFT },
{ "top-constraint", GTK_CONSTRAINT_ATTRIBUTE_TOP },
{ "width-constraint", GTK_CONSTRAINT_ATTRIBUTE_WIDTH },
{ "height-constraint", GTK_CONSTRAINT_ATTRIBUTE_HEIGHT },
};
int i;
name = gtk_constraint_guide_get_name (guide);
label = gtk_label_new (name);
g_object_bind_property (guide, "name",
label, "label",
G_BINDING_DEFAULT);
frame = gtk_frame_new (NULL);
gtk_widget_add_css_class (frame, "guide");
g_object_set_data (G_OBJECT (frame), "internal", (char *)"yes");
gtk_frame_set_child (GTK_FRAME (frame), label);
gtk_widget_insert_after (frame, GTK_WIDGET (view), NULL);
g_object_set_data (G_OBJECT (guide), "frame", frame);
layout = GTK_CONSTRAINT_LAYOUT (gtk_widget_get_layout_manager (GTK_WIDGET (view)));
gtk_constraint_layout_add_guide (layout, g_object_ref (guide));
for (i = 0; i < G_N_ELEMENTS (names); i++)
{
constraint = gtk_constraint_new (frame,
names[i].attr,
GTK_CONSTRAINT_RELATION_EQ,
guide,
names[i].attr,
1.0, 0.0,
GTK_CONSTRAINT_STRENGTH_REQUIRED);
g_object_set_data (G_OBJECT (constraint), "internal", (char *)"yes");
gtk_constraint_layout_add_constraint (layout, constraint);
g_object_set_data (G_OBJECT (guide), names[i].name, constraint);
}
update_weak_position (view, frame, 150, 150);
}
void
constraint_view_remove_guide (ConstraintView *view,
GtkConstraintGuide *guide)
{
GtkConstraintLayout *layout;
GtkWidget *frame;
GtkConstraint *constraint;
const char *names[] = {
"left-constraint",
"top-constraint",
"width-constraint",
"height-constraint"
};
int i;
layout = GTK_CONSTRAINT_LAYOUT (gtk_widget_get_layout_manager (GTK_WIDGET (view)));
for (i = 0; i < G_N_ELEMENTS (names); i++)
{
constraint = (GtkConstraint*)g_object_get_data (G_OBJECT (guide), names[i]);
gtk_constraint_layout_remove_constraint (layout, constraint);
}
frame = (GtkWidget *)g_object_get_data (G_OBJECT (guide), "frame");
update_weak_position (view, frame, -100, -100);
gtk_widget_unparent (frame);
gtk_constraint_layout_remove_guide (layout, guide);
}
void
constraint_view_add_constraint (ConstraintView *view,
GtkConstraint *constraint)
{
GtkLayoutManager *manager;
manager = gtk_widget_get_layout_manager (GTK_WIDGET (view));
gtk_constraint_layout_add_constraint (GTK_CONSTRAINT_LAYOUT (manager),
g_object_ref (constraint));
}
void
constraint_view_remove_constraint (ConstraintView *view,
GtkConstraint *constraint)
{
GtkLayoutManager *manager;
manager = gtk_widget_get_layout_manager (GTK_WIDGET (view));
gtk_constraint_layout_remove_constraint (GTK_CONSTRAINT_LAYOUT (manager),
constraint);
}
GListModel *
constraint_view_get_model (ConstraintView *view)
{
return view->model;
}