gtk2/gtk/gtkviewport.c
2020-04-26 15:38:09 -04:00

636 lines
19 KiB
C
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/* GTK - The GIMP Toolkit
* Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
*
* 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 "gtkviewport.h"
#include "gtkadjustmentprivate.h"
#include "gtkintl.h"
#include "gtkmarshalers.h"
#include "gtkprivate.h"
#include "gtkscrollable.h"
#include "gtkstylecontext.h"
#include "gtktypebuiltins.h"
#include "gtkwidgetprivate.h"
#include "gtktext.h"
/**
* SECTION:gtkviewport
* @Short_description: An adapter which makes widgets scrollable
* @Title: GtkViewport
* @See_also:#GtkScrolledWindow, #GtkAdjustment
*
* The #GtkViewport widget acts as an adaptor class, implementing
* scrollability for child widgets that lack their own scrolling
* capabilities. Use GtkViewport to scroll child widgets such as
* #GtkGrid, #GtkBox, and so on.
*
* If a widget has native scrolling abilities, such as #GtkTextView,
* #GtkTreeView or #GtkIconView, it can be added to a #GtkScrolledWindow
* with gtk_container_add(). If a widget does not, you must first add the
* widget to a #GtkViewport, then add the viewport to the scrolled window.
* gtk_container_add() does this automatically if a child that does not
* implement #GtkScrollable is added to a #GtkScrolledWindow, so you can
* ignore the presence of the viewport.
*
* The GtkViewport will start scrolling content only if allocated less
* than the child widgets minimum size in a given orientation.
*
* # CSS nodes
*
* GtkViewport has a single CSS node with name viewport.
*/
typedef struct _GtkViewportPrivate GtkViewportPrivate;
typedef struct _GtkViewportClass GtkViewportClass;
struct _GtkViewport
{
GtkBin parent_instance;
GtkAdjustment *hadjustment;
GtkAdjustment *vadjustment;
/* GtkScrollablePolicy needs to be checked when
* driving the scrollable adjustment values */
guint hscroll_policy : 1;
guint vscroll_policy : 1;
guint scroll_to_focus : 1;
gulong focus_handler;
};
struct _GtkViewportClass
{
GtkBinClass parent_class;
};
enum {
PROP_0,
PROP_HADJUSTMENT,
PROP_VADJUSTMENT,
PROP_HSCROLL_POLICY,
PROP_VSCROLL_POLICY,
PROP_SCROLL_TO_FOCUS
};
static void gtk_viewport_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec);
static void gtk_viewport_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec);
static void gtk_viewport_destroy (GtkWidget *widget);
static void gtk_viewport_size_allocate (GtkWidget *widget,
int width,
int height,
int baseline);
static void gtk_viewport_adjustment_value_changed (GtkAdjustment *adjustment,
gpointer data);
static void viewport_set_adjustment (GtkViewport *viewport,
GtkOrientation orientation,
GtkAdjustment *adjustment);
static void setup_focus_change_handler (GtkViewport *viewport);
static void clear_focus_change_handler (GtkViewport *viewport);
G_DEFINE_TYPE_WITH_CODE (GtkViewport, gtk_viewport, GTK_TYPE_BIN,
G_IMPLEMENT_INTERFACE (GTK_TYPE_SCROLLABLE, NULL))
static void
viewport_set_adjustment_values (GtkViewport *viewport,
GtkOrientation orientation)
{
GtkBin *bin = GTK_BIN (viewport);
GtkAdjustment *adjustment;
GtkScrollablePolicy scroll_policy;
GtkScrollablePolicy other_scroll_policy;
GtkOrientation other_orientation;
GtkWidget *child;
gdouble upper, value;
int viewport_size, other_viewport_size;
int view_width, view_height;
view_width = gtk_widget_get_width (GTK_WIDGET (viewport));
view_height = gtk_widget_get_height (GTK_WIDGET (viewport));
if (orientation == GTK_ORIENTATION_HORIZONTAL)
{
adjustment = viewport->hadjustment;
other_orientation = GTK_ORIENTATION_VERTICAL;
viewport_size = view_width;
other_viewport_size = view_height;
scroll_policy = viewport->hscroll_policy;
other_scroll_policy = viewport->vscroll_policy;
}
else /* VERTICAL */
{
adjustment = viewport->vadjustment;
other_orientation = GTK_ORIENTATION_HORIZONTAL;
viewport_size = view_height;
other_viewport_size = view_width;
scroll_policy = viewport->vscroll_policy;
other_scroll_policy = viewport->hscroll_policy;
}
child = gtk_bin_get_child (bin);
if (child && gtk_widget_get_visible (child))
{
int min_size, nat_size;
int scroll_size;
if (other_scroll_policy == GTK_SCROLL_MINIMUM)
gtk_widget_measure (child, other_orientation, -1,
&scroll_size, NULL, NULL, NULL);
else
gtk_widget_measure (child, other_orientation, -1,
NULL, &scroll_size, NULL, NULL);
gtk_widget_measure (child, orientation,
MAX (other_viewport_size, scroll_size),
&min_size, &nat_size, NULL, NULL);
if (scroll_policy == GTK_SCROLL_MINIMUM)
upper = MAX (min_size, viewport_size);
else
upper = MAX (nat_size, viewport_size);
}
else
{
upper = viewport_size;
}
value = gtk_adjustment_get_value (adjustment);
/* We clamp to the left in RTL mode */
if (orientation == GTK_ORIENTATION_HORIZONTAL &&
_gtk_widget_get_direction (GTK_WIDGET (viewport)) == GTK_TEXT_DIR_RTL)
{
gdouble dist = gtk_adjustment_get_upper (adjustment)
- value
- gtk_adjustment_get_page_size (adjustment);
value = upper - dist - viewport_size;
}
gtk_adjustment_configure (adjustment,
value,
0,
upper,
viewport_size * 0.1,
viewport_size * 0.9,
viewport_size);
}
static void
gtk_viewport_measure (GtkWidget *widget,
GtkOrientation orientation,
int for_size,
int *minimum,
int *natural,
int *minimum_baseline,
int *natural_baseline)
{
GtkWidget *child;
*minimum = *natural = 0;
child = gtk_bin_get_child (GTK_BIN (widget));
if (child && gtk_widget_get_visible (child))
gtk_widget_measure (child,
orientation,
for_size,
minimum, natural,
NULL, NULL);
}
static void
gtk_viewport_dispose (GObject *object)
{
clear_focus_change_handler (GTK_VIEWPORT (object));
G_OBJECT_CLASS (gtk_viewport_parent_class)->dispose (object);
}
static void
gtk_viewport_root (GtkWidget *widget)
{
GtkViewport *viewport = GTK_VIEWPORT (widget);
GTK_WIDGET_CLASS (gtk_viewport_parent_class)->root (widget);
if (viewport->scroll_to_focus)
setup_focus_change_handler (viewport);
}
static void
gtk_viewport_unroot (GtkWidget *widget)
{
GtkViewport *viewport = GTK_VIEWPORT (widget);
if (viewport->scroll_to_focus)
clear_focus_change_handler (viewport);
GTK_WIDGET_CLASS (gtk_viewport_parent_class)->unroot (widget);
}
static void
gtk_viewport_class_init (GtkViewportClass *class)
{
GObjectClass *gobject_class;
GtkWidgetClass *widget_class;
gobject_class = G_OBJECT_CLASS (class);
widget_class = (GtkWidgetClass*) class;
gobject_class->dispose = gtk_viewport_dispose;
gobject_class->set_property = gtk_viewport_set_property;
gobject_class->get_property = gtk_viewport_get_property;
widget_class->destroy = gtk_viewport_destroy;
widget_class->size_allocate = gtk_viewport_size_allocate;
widget_class->measure = gtk_viewport_measure;
widget_class->root = gtk_viewport_root;
widget_class->unroot = gtk_viewport_unroot;
gtk_widget_class_set_accessible_role (widget_class, ATK_ROLE_VIEWPORT);
/* GtkScrollable implementation */
g_object_class_override_property (gobject_class, PROP_HADJUSTMENT, "hadjustment");
g_object_class_override_property (gobject_class, PROP_VADJUSTMENT, "vadjustment");
g_object_class_override_property (gobject_class, PROP_HSCROLL_POLICY, "hscroll-policy");
g_object_class_override_property (gobject_class, PROP_VSCROLL_POLICY, "vscroll-policy");
g_object_class_install_property (gobject_class,
PROP_SCROLL_TO_FOCUS,
g_param_spec_boolean ("scroll-to-focus",
P_("Scroll to focus"),
P_("Whether to scroll when the focus changes"),
FALSE,
GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY));
gtk_widget_class_set_css_name (widget_class, I_("viewport"));
}
static void
gtk_viewport_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GtkViewport *viewport = GTK_VIEWPORT (object);
switch (prop_id)
{
case PROP_HADJUSTMENT:
viewport_set_adjustment (viewport, GTK_ORIENTATION_HORIZONTAL, g_value_get_object (value));
break;
case PROP_VADJUSTMENT:
viewport_set_adjustment (viewport, GTK_ORIENTATION_VERTICAL, g_value_get_object (value));
break;
case PROP_HSCROLL_POLICY:
if (viewport->hscroll_policy != g_value_get_enum (value))
{
viewport->hscroll_policy = g_value_get_enum (value);
gtk_widget_queue_resize (GTK_WIDGET (viewport));
g_object_notify_by_pspec (object, pspec);
}
break;
case PROP_VSCROLL_POLICY:
if (viewport->vscroll_policy != g_value_get_enum (value))
{
viewport->vscroll_policy = g_value_get_enum (value);
gtk_widget_queue_resize (GTK_WIDGET (viewport));
g_object_notify_by_pspec (object, pspec);
}
break;
case PROP_SCROLL_TO_FOCUS:
gtk_viewport_set_scroll_to_focus (viewport, g_value_get_boolean (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gtk_viewport_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GtkViewport *viewport = GTK_VIEWPORT (object);
switch (prop_id)
{
case PROP_HADJUSTMENT:
g_value_set_object (value, viewport->hadjustment);
break;
case PROP_VADJUSTMENT:
g_value_set_object (value, viewport->vadjustment);
break;
case PROP_HSCROLL_POLICY:
g_value_set_enum (value, viewport->hscroll_policy);
break;
case PROP_VSCROLL_POLICY:
g_value_set_enum (value, viewport->vscroll_policy);
break;
case PROP_SCROLL_TO_FOCUS:
g_value_set_boolean (value, viewport->scroll_to_focus);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gtk_viewport_init (GtkViewport *viewport)
{
GtkWidget *widget;
widget = GTK_WIDGET (viewport);
gtk_widget_set_overflow (widget, GTK_OVERFLOW_HIDDEN);
viewport->hadjustment = NULL;
viewport->vadjustment = NULL;
gtk_widget_add_css_class (widget, GTK_STYLE_CLASS_FRAME);
viewport_set_adjustment (viewport, GTK_ORIENTATION_HORIZONTAL, NULL);
viewport_set_adjustment (viewport, GTK_ORIENTATION_VERTICAL, NULL);
}
/**
* gtk_viewport_new:
* @hadjustment: (allow-none): horizontal adjustment
* @vadjustment: (allow-none): vertical adjustment
*
* Creates a new #GtkViewport with the given adjustments, or with default
* adjustments if none are given.
*
* Returns: a new #GtkViewport
*/
GtkWidget*
gtk_viewport_new (GtkAdjustment *hadjustment,
GtkAdjustment *vadjustment)
{
GtkWidget *viewport;
viewport = g_object_new (GTK_TYPE_VIEWPORT,
"hadjustment", hadjustment,
"vadjustment", vadjustment,
NULL);
return viewport;
}
#define ADJUSTMENT_POINTER(orientation) \
(((orientation) == GTK_ORIENTATION_HORIZONTAL) ? \
&viewport->hadjustment : &viewport->vadjustment)
static void
viewport_disconnect_adjustment (GtkViewport *viewport,
GtkOrientation orientation)
{
GtkAdjustment **adjustmentp = ADJUSTMENT_POINTER (orientation);
if (*adjustmentp)
{
g_signal_handlers_disconnect_by_func (*adjustmentp,
gtk_viewport_adjustment_value_changed,
viewport);
g_object_unref (*adjustmentp);
*adjustmentp = NULL;
}
}
static void
gtk_viewport_destroy (GtkWidget *widget)
{
GtkViewport *viewport = GTK_VIEWPORT (widget);
viewport_disconnect_adjustment (viewport, GTK_ORIENTATION_HORIZONTAL);
viewport_disconnect_adjustment (viewport, GTK_ORIENTATION_VERTICAL);
GTK_WIDGET_CLASS (gtk_viewport_parent_class)->destroy (widget);
}
static void
viewport_set_adjustment (GtkViewport *viewport,
GtkOrientation orientation,
GtkAdjustment *adjustment)
{
GtkAdjustment **adjustmentp = ADJUSTMENT_POINTER (orientation);
if (adjustment && adjustment == *adjustmentp)
return;
if (!adjustment)
adjustment = gtk_adjustment_new (0.0, 0.0, 0.0, 0.0, 0.0, 0.0);
viewport_disconnect_adjustment (viewport, orientation);
*adjustmentp = adjustment;
g_object_ref_sink (adjustment);
viewport_set_adjustment_values (viewport, orientation);
g_signal_connect (adjustment, "value-changed",
G_CALLBACK (gtk_viewport_adjustment_value_changed),
viewport);
gtk_viewport_adjustment_value_changed (adjustment, viewport);
}
static void
gtk_viewport_size_allocate (GtkWidget *widget,
int width,
int height,
int baseline)
{
GtkViewport *viewport = GTK_VIEWPORT (widget);
GtkAdjustment *hadjustment = viewport->hadjustment;
GtkAdjustment *vadjustment = viewport->vadjustment;
GtkWidget *child;
g_object_freeze_notify (G_OBJECT (hadjustment));
g_object_freeze_notify (G_OBJECT (vadjustment));
viewport_set_adjustment_values (viewport, GTK_ORIENTATION_HORIZONTAL);
viewport_set_adjustment_values (viewport, GTK_ORIENTATION_VERTICAL);
child = gtk_bin_get_child (GTK_BIN (widget));
if (child && gtk_widget_get_visible (child))
{
GtkAllocation child_allocation;
child_allocation.x = - gtk_adjustment_get_value (hadjustment);
child_allocation.y = - gtk_adjustment_get_value (vadjustment);
child_allocation.width = gtk_adjustment_get_upper (hadjustment);
child_allocation.height = gtk_adjustment_get_upper (vadjustment);
gtk_widget_size_allocate (child, &child_allocation, -1);
}
g_object_thaw_notify (G_OBJECT (hadjustment));
g_object_thaw_notify (G_OBJECT (vadjustment));
}
static void
gtk_viewport_adjustment_value_changed (GtkAdjustment *adjustment,
gpointer data)
{
gtk_widget_queue_allocate (GTK_WIDGET (data));
}
/**
* gtk_viewport_get_scroll_to_focus:
* @viewport: a #GtkViewport
*
* Gets whether the viewport is scrolling to keep the focused
* child in view. See gtk_viewport_set_scroll_to_focus().
*
* Returns: %TRUE if the viewport keeps the focus child scrolled to view
*/
gboolean
gtk_viewport_get_scroll_to_focus (GtkViewport *viewport)
{
g_return_val_if_fail (GTK_IS_VIEWPORT (viewport), FALSE);
return viewport->scroll_to_focus;
}
/**
* gtk_viewport_set_scroll_to_focus:
* @viewport: a #GtkViewport
* @scroll_to_focus: whether to keep the focus widget scrolled to view
*
* Sets whether the viewport should automatically scroll
* to keep the focused child in view.
*/
void
gtk_viewport_set_scroll_to_focus (GtkViewport *viewport,
gboolean scroll_to_focus)
{
g_return_if_fail (GTK_IS_VIEWPORT (viewport));
if (viewport->scroll_to_focus == scroll_to_focus)
return;
viewport->scroll_to_focus = scroll_to_focus;
if (gtk_widget_get_root (GTK_WIDGET (viewport)))
{
if (scroll_to_focus)
setup_focus_change_handler (viewport);
else
clear_focus_change_handler (viewport);
}
g_object_notify (G_OBJECT (viewport), "scroll-to-focus");
}
static void
scroll_to_view (GtkAdjustment *adj,
double pos,
double size)
{
double value, page_size;
value = gtk_adjustment_get_value (adj);
page_size = gtk_adjustment_get_page_size (adj);
if (pos < 0)
gtk_adjustment_animate_to_value (adj, value + pos);
else if (pos + size >= page_size)
gtk_adjustment_animate_to_value (adj, value + pos + size - page_size);
}
static void
focus_change_handler (GtkWidget *widget)
{
GtkViewport *viewport = GTK_VIEWPORT (widget);
GtkRoot *root;
GtkWidget *focus_widget;
GtkWidget *child;
graphene_rect_t rect;
int x, y;
if ((gtk_widget_get_state_flags (widget) & GTK_STATE_FLAG_FOCUS_WITHIN) == 0)
return;
root = gtk_widget_get_root (widget);
focus_widget = gtk_root_get_focus (root);
if (!focus_widget)
return;
if (GTK_IS_TEXT (focus_widget))
focus_widget = gtk_widget_get_parent (focus_widget);
child = gtk_bin_get_child (GTK_BIN (viewport));
if (!gtk_widget_compute_bounds (focus_widget, child, &rect))
return;
gtk_widget_translate_coordinates (child, widget,
(int)rect.origin.x,
(int)rect.origin.y,
&x, &y);
scroll_to_view (viewport->hadjustment, x, rect.size.width);
scroll_to_view (viewport->vadjustment, y, rect.size.height);
}
static void
setup_focus_change_handler (GtkViewport *viewport)
{
GtkRoot *root;
root = gtk_widget_get_root (GTK_WIDGET (viewport));
viewport->focus_handler = g_signal_connect_swapped (root, "notify::focus-widget",
G_CALLBACK (focus_change_handler), viewport);
}
static void
clear_focus_change_handler (GtkViewport *viewport)
{
GtkRoot *root;
root = gtk_widget_get_root (GTK_WIDGET (viewport));
if (viewport->focus_handler)
{
g_signal_handler_disconnect (root, viewport->focus_handler);
viewport->focus_handler = 0;
}
}