demos/constraint-editor/constraint-view.c - external/github.com/GNOME/gtk - Git at Google

 /* 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);

   guides = gtk_constraint_layout_observe_guides (GTK_CONSTRAINT_LAYOUT (manager));

   all_constraints = gtk_constraint_layout_observe_constraints (GTK_CONSTRAINT_LAYOUT (manager));
   filter = GTK_FILTER (gtk_custom_filter_new (omit_internal, NULL, NULL));
   constraints = (GListModel *)gtk_filter_list_model_new (all_constraints, filter);

   all_children = gtk_widget_observe_children (GTK_WIDGET (self));
   filter = GTK_FILTER (gtk_custom_filter_new (omit_internal, NULL, NULL));
   children = (GListModel *)gtk_filter_list_model_new (all_children, 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);
   g_object_unref (children);
   g_object_unref (guides);
   g_object_unref (constraints);

   self->model = G_LIST_MODEL (gtk_flatten_list_model_new (G_LIST_MODEL (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;
 }
	/* 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);

	guides = gtk_constraint_layout_observe_guides (GTK_CONSTRAINT_LAYOUT (manager));

	all_constraints = gtk_constraint_layout_observe_constraints (GTK_CONSTRAINT_LAYOUT (manager));
	filter = GTK_FILTER (gtk_custom_filter_new (omit_internal, NULL, NULL));
	constraints = (GListModel *)gtk_filter_list_model_new (all_constraints, filter);

	all_children = gtk_widget_observe_children (GTK_WIDGET (self));
	filter = GTK_FILTER (gtk_custom_filter_new (omit_internal, NULL, NULL));
	children = (GListModel *)gtk_filter_list_model_new (all_children, 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);
	g_object_unref (children);
	g_object_unref (guides);
	g_object_unref (constraints);

	self->model = G_LIST_MODEL (gtk_flatten_list_model_new (G_LIST_MODEL (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;
	}