gtk2/gtk/gtkscrollbar.c
Matthias Clasen 5205fa0ff7 scrollbar: Be more defensive
Somehow the scrollbar accessible manages to call
gtk_scrollbar_get_adjustment when priv->range is NULL.
Survive taht.
2020-04-03 23:31:45 -04:00

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/* GTK - The GIMP Toolkit
* Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
* Copyright (C) 2001 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/>.
*/
/*
* Modified by the GTK+ Team and others 1997-2000. See the AUTHORS
* file for a list of people on the GTK+ Team. See the ChangeLog
* files for a list of changes. These files are distributed with
* GTK+ at ftp://ftp.gtk.org/pub/gtk/.
*/
#include "config.h"
#include "gtkscrollbar.h"
#include "gtkrange.h"
#include "gtkadjustment.h"
#include "gtkintl.h"
#include "gtkorientable.h"
#include "gtkorientableprivate.h"
#include "gtkprivate.h"
#include "gtkboxlayout.h"
#include "a11y/gtkscrollbaraccessible.h"
/**
* SECTION:gtkscrollbar
* @Short_description: A Scrollbar
* @Title: GtkScrollbar
* @See_also: #GtkAdjustment, #GtkScrolledWindow
*
* The #GtkScrollbar widget is a horizontal or vertical scrollbar,
* depending on the value of the #GtkOrientable:orientation property.
*
* Its position and movement are controlled by the adjustment that is passed to
* or created by gtk_scrollbar_new(). See #GtkAdjustment for more details. The
* #GtkAdjustment:value field sets the position of the thumb and must be between
* #GtkAdjustment:lower and #GtkAdjustment:upper - #GtkAdjustment:page-size. The
* #GtkAdjustment:page-size represents the size of the visible scrollable area.
* The fields #GtkAdjustment:step-increment and #GtkAdjustment:page-increment
* fields are added to or subtracted from the #GtkAdjustment:value when the user
* asks to move by a step (using e.g. the cursor arrow keys or, if present, the
* stepper buttons) or by a page (using e.g. the Page Down/Up keys).
*
* # CSS nodes
*
* |[<!-- language="plain" -->
* scrollbar
* ╰── range[.fine-tune]
* ╰── trough
* ╰── slider
* ]|
*
* GtkScrollbar has a main CSS node with name scrollbar and a subnode for its
* contents. The main node gets the .horizontal or .vertical
* style classes applied, depending on the scrollbar's orientation.
*
* The range node gets the style class .fine-tune added when the scrollbar is
* in 'fine-tuning' mode.
*
* If steppers are enabled, they are represented by up to four additional
* subnodes with name button. These get the style classes .up and .down to
* indicate in which direction they are moving.
*
* Other style classes that may be added to scrollbars inside #GtkScrolledWindow
* include the positional classes (.left, .right, .top, .bottom) and style
* classes related to overlay scrolling (.overlay-indicator, .dragging, .hovering).
*/
typedef struct _GtkScrollbarClass GtkScrollbarClass;
struct _GtkScrollbar
{
GtkWidget parent_instance;
};
struct _GtkScrollbarClass
{
GtkWidgetClass parent_class;
};
typedef struct {
GtkOrientation orientation;
GtkWidget *range;
} GtkScrollbarPrivate;
enum {
PROP_0,
PROP_ADJUSTMENT,
PROP_ORIENTATION,
LAST_PROP = PROP_ORIENTATION
};
G_DEFINE_TYPE_WITH_CODE (GtkScrollbar, gtk_scrollbar, GTK_TYPE_WIDGET,
G_ADD_PRIVATE (GtkScrollbar)
G_IMPLEMENT_INTERFACE (GTK_TYPE_ORIENTABLE, NULL))
static GParamSpec *props[LAST_PROP] = { NULL, };
static void
gtk_scrollbar_get_property (GObject *object,
guint property_id,
GValue *value,
GParamSpec *pspec)
{
GtkScrollbar *self = GTK_SCROLLBAR (object);
GtkScrollbarPrivate *priv = gtk_scrollbar_get_instance_private (self);
switch (property_id)
{
case PROP_ADJUSTMENT:
g_value_set_object (value, gtk_scrollbar_get_adjustment (self));
break;
case PROP_ORIENTATION:
g_value_set_enum (value, priv->orientation);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
break;
}
}
static void
gtk_scrollbar_set_property (GObject *object,
guint property_id,
const GValue *value,
GParamSpec *pspec)
{
GtkScrollbar *self = GTK_SCROLLBAR (object);
GtkScrollbarPrivate *priv = gtk_scrollbar_get_instance_private (self);
switch (property_id)
{
case PROP_ADJUSTMENT:
gtk_scrollbar_set_adjustment (self, g_value_get_object (value));
break;
case PROP_ORIENTATION:
{
GtkOrientation orientation = g_value_get_enum (value);
if (orientation != priv->orientation)
{
GtkLayoutManager *layout = gtk_widget_get_layout_manager (GTK_WIDGET (self));
gtk_orientable_set_orientation (GTK_ORIENTABLE (layout), orientation);
gtk_orientable_set_orientation (GTK_ORIENTABLE (priv->range), orientation);
priv->orientation = orientation;
_gtk_orientable_set_style_classes (GTK_ORIENTABLE (self));
gtk_widget_queue_resize (GTK_WIDGET (self));
g_object_notify_by_pspec (object, pspec);
}
}
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
break;
}
}
static void
gtk_scrollbar_dispose (GObject *object)
{
GtkScrollbar *self = GTK_SCROLLBAR (object);
GtkScrollbarPrivate *priv = gtk_scrollbar_get_instance_private (self);
g_clear_pointer (&priv->range, gtk_widget_unparent);
G_OBJECT_CLASS (gtk_scrollbar_parent_class)->dispose (object);
}
static void
gtk_scrollbar_class_init (GtkScrollbarClass *class)
{
GObjectClass *object_class = G_OBJECT_CLASS (class);
GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (class);
object_class->get_property = gtk_scrollbar_get_property;
object_class->set_property = gtk_scrollbar_set_property;
object_class->dispose = gtk_scrollbar_dispose;
props[PROP_ADJUSTMENT] =
g_param_spec_object ("adjustment",
P_("Adjustment"),
P_("The GtkAdjustment that contains the current value of this scrollbar"),
GTK_TYPE_ADJUSTMENT,
GTK_PARAM_READWRITE|G_PARAM_CONSTRUCT);
g_object_class_install_properties (object_class, LAST_PROP, props);
g_object_class_override_property (object_class, PROP_ORIENTATION, "orientation");
gtk_widget_class_set_accessible_type (widget_class, GTK_TYPE_SCROLLBAR_ACCESSIBLE);
gtk_widget_class_set_css_name (widget_class, I_("scrollbar"));
gtk_widget_class_set_layout_manager_type (widget_class, GTK_TYPE_BOX_LAYOUT);
}
static void
gtk_scrollbar_init (GtkScrollbar *self)
{
GtkScrollbarPrivate *priv = gtk_scrollbar_get_instance_private (self);
priv->orientation = GTK_ORIENTATION_HORIZONTAL;
priv->range = g_object_new (GTK_TYPE_RANGE, NULL);
gtk_widget_set_hexpand (priv->range, TRUE);
gtk_widget_set_vexpand (priv->range, TRUE);
gtk_widget_set_parent (priv->range, GTK_WIDGET (self));
_gtk_orientable_set_style_classes (GTK_ORIENTABLE (self));
}
/**
* gtk_scrollbar_new:
* @orientation: the scrollbars orientation.
* @adjustment: (allow-none): the #GtkAdjustment to use, or %NULL to create a new adjustment.
*
* Creates a new scrollbar with the given orientation.
*
* Returns: the new #GtkScrollbar.
**/
GtkWidget *
gtk_scrollbar_new (GtkOrientation orientation,
GtkAdjustment *adjustment)
{
g_return_val_if_fail (adjustment == NULL || GTK_IS_ADJUSTMENT (adjustment),
NULL);
return g_object_new (GTK_TYPE_SCROLLBAR,
"orientation", orientation,
"adjustment", adjustment,
NULL);
}
/**
* gtk_scrollbar_set_adjustment:
* @self: a #GtkScrollbar
* @adjustment: (nullable): the adjustment to set
*
* Makes the scrollbar use the given adjustment.
*/
void
gtk_scrollbar_set_adjustment (GtkScrollbar *self,
GtkAdjustment *adjustment)
{
GtkScrollbarPrivate *priv = gtk_scrollbar_get_instance_private (self);
g_return_if_fail (GTK_IS_SCROLLBAR (self));
g_return_if_fail (adjustment == NULL || GTK_IS_ADJUSTMENT (adjustment));
gtk_range_set_adjustment (GTK_RANGE (priv->range), adjustment);
g_object_notify_by_pspec (G_OBJECT (self), props[PROP_ADJUSTMENT]);
}
/**
* gtk_scrollbar_get_adjustment:
* @self: a #GtkScrollbar
*
* Returns the scrollbar's adjustment.
*
* Returns: (transfer none): the scrollbar's adjustment
*/
GtkAdjustment *
gtk_scrollbar_get_adjustment (GtkScrollbar *self)
{
GtkScrollbarPrivate *priv = gtk_scrollbar_get_instance_private (self);
g_return_val_if_fail (GTK_IS_SCROLLBAR (self), NULL);
if (priv->range)
return gtk_range_get_adjustment (GTK_RANGE (priv->range));
return NULL;
}