gtk2/gtk/gtkcolorplane.c
Emmanuele Bassi c63087a563 Remove ATK
To build a better world sometimes means having to tear the old one down.
        -- Alexander Pierce, "Captain America: The Winter Soldier"

ATK served us well for nearly 20 years, but the world has changed, and
GTK has changed with it. Now ATK is mostly a hindrance towards improving
the accessibility stack:

 - it maps to a very specific implementation, AT-SPI, which is Linux and
   Unix specific
 - it requires implementing the same functionality in three different
   layers of the stack: AT-SPI, ATK, and GTK
 - only GTK uses it; every other Linux and Unix toolkit and application
   talks to AT-SPI directly, including assistive technologies

Sadly, we cannot incrementally port GTK to a new accessibility stack;
since ATK insulates us entirely from the underlying implementation, we
cannot replace it piecemeal. Instead, we're going to remove everything
and then incrementally build on a clean slate:

 - add an "accessible" interface, implemented by GTK objects directly,
   which describe the accessible role and state changes for every UI
   element
 - add an "assistive technology context" to proxy a native accessibility
   API, and assign it to every widget
 - implement the AT context depending on the platform

For more information, see: https://gitlab.gnome.org/GNOME/gtk/-/issues/2833
2020-07-26 20:31:14 +01:00

558 lines
16 KiB
C

/* GTK - The GIMP Toolkit
* Copyright (C) 2012 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 "config.h"
#include "gtkcolorplaneprivate.h"
#include "gtkadjustment.h"
#include "gtkcolorutils.h"
#include "gtkgesturedrag.h"
#include "gtkgesturelongpress.h"
#include "gtkintl.h"
#include "gtksnapshot.h"
#include "gtkprivate.h"
#include "gtkeventcontrollerkey.h"
#include "gtkshortcutcontroller.h"
#include "gtkshortcuttrigger.h"
#include "gtkshortcutaction.h"
#include "gtkshortcut.h"
struct _GtkColorPlane
{
GtkWidget parent_instance;
GtkAdjustment *h_adj;
GtkAdjustment *s_adj;
GtkAdjustment *v_adj;
GdkTexture *texture;
};
typedef struct
{
GtkWidgetClass parent_class;
} GtkColorPlaneClass;
enum {
PROP_0,
PROP_H_ADJUSTMENT,
PROP_S_ADJUSTMENT,
PROP_V_ADJUSTMENT
};
G_DEFINE_TYPE (GtkColorPlane, gtk_color_plane, GTK_TYPE_WIDGET)
static void
sv_to_xy (GtkColorPlane *plane,
int *x,
int *y)
{
double s, v;
int width, height;
width = gtk_widget_get_width (GTK_WIDGET (plane));
height = gtk_widget_get_height (GTK_WIDGET (plane));
s = gtk_adjustment_get_value (plane->s_adj);
v = gtk_adjustment_get_value (plane->v_adj);
*x = CLAMP (width * v, 0, width - 1);
*y = CLAMP (height * (1 - s), 0, height - 1);
}
static void
plane_snapshot (GtkWidget *widget,
GtkSnapshot *snapshot)
{
GtkColorPlane *plane = GTK_COLOR_PLANE (widget);
int x, y;
int width, height;
sv_to_xy (plane, &x, &y);
width = gtk_widget_get_width (widget);
height = gtk_widget_get_height (widget);
gtk_snapshot_append_texture (snapshot,
plane->texture,
&GRAPHENE_RECT_INIT (0, 0, width, height));
if (gtk_widget_has_visible_focus (widget))
{
const GdkRGBA c1 = { 1.0, 1.0, 1.0, 0.6 };
const GdkRGBA c2 = { 0.0, 0.0, 0.0, 0.8 };
/* Crosshair border */
gtk_snapshot_append_color (snapshot, &c1,
&GRAPHENE_RECT_INIT (0, y - 1.5, width, 3));
gtk_snapshot_append_color (snapshot, &c1,
&GRAPHENE_RECT_INIT (x - 1.5, 0, 3, height));
/* Actual crosshair */
gtk_snapshot_append_color (snapshot, &c2,
&GRAPHENE_RECT_INIT (0, y - 0.5, width, 1));
gtk_snapshot_append_color (snapshot, &c2,
&GRAPHENE_RECT_INIT (x - 0.5, 0, 1, height));
}
else
{
const GdkRGBA c = { 0.8, 0.8, 0.8, 0.8 };
/* Horizontal */
gtk_snapshot_append_color (snapshot, &c,
&GRAPHENE_RECT_INIT (0, y - 0.5, width, 1));
/* Vertical */
gtk_snapshot_append_color (snapshot, &c,
&GRAPHENE_RECT_INIT (x - 0.5, 0, 1, height));
}
}
static void
create_texture (GtkColorPlane *plane)
{
GtkWidget *widget = GTK_WIDGET (plane);
GBytes *bytes;
int width, height, stride;
guint red, green, blue;
guint32 *data, *p;
float h, s, v;
float r, g, b;
double sf, vf;
int x, y;
if (!gtk_widget_get_realized (widget))
return;
width = gtk_widget_get_width (widget);
height = gtk_widget_get_height (widget);
if (width == 0 || height == 0)
return;
g_clear_object (&plane->texture);
stride = width * 4;
data = g_malloc (height * stride);
if (width > 1 && height > 1)
{
h = gtk_adjustment_get_value (plane->h_adj);
sf = 1.0 / (height - 1);
vf = 1.0 / (width - 1);
for (y = 0; y < height; y++)
{
s = CLAMP (1.0 - y * sf, 0.0, 1.0);
p = data + y * (stride / 4);
for (x = 0; x < width; x++)
{
v = x * vf;
gtk_hsv_to_rgb (h, s, v, &r, &g, &b);
red = CLAMP (r * 255, 0, 255);
green = CLAMP (g * 255, 0, 255);
blue = CLAMP (b * 255, 0, 255);
p[x] = (0xff << 24) | (red << 16) | (green << 8) | blue;
}
}
}
else
{
memset (data, 0, height * stride);
}
bytes = g_bytes_new_take (data, height * stride);
plane->texture = gdk_memory_texture_new (width, height,
GDK_MEMORY_DEFAULT,
bytes,
stride);
g_bytes_unref (bytes);
}
static void
plane_size_allocate (GtkWidget *widget,
int width,
int height,
int baseline)
{
GtkColorPlane *plane = GTK_COLOR_PLANE (widget);
create_texture (plane);
}
static void
plane_realize (GtkWidget *widget)
{
GTK_WIDGET_CLASS (gtk_color_plane_parent_class)->realize (widget);
create_texture (GTK_COLOR_PLANE (widget));
}
static void
plane_unrealize (GtkWidget *widget)
{
GtkColorPlane *plane = GTK_COLOR_PLANE (widget);
g_clear_object (&plane->texture);
GTK_WIDGET_CLASS (gtk_color_plane_parent_class)->unrealize (widget);
}
static void
set_cross_cursor (GtkWidget *widget,
gboolean enabled)
{
if (enabled)
gtk_widget_set_cursor_from_name (widget, "crosshair");
else
gtk_widget_set_cursor (widget, NULL);
}
static void
h_changed (GtkColorPlane *plane)
{
create_texture (plane);
gtk_widget_queue_draw (GTK_WIDGET (plane));
}
static void
sv_changed (GtkColorPlane *plane)
{
gtk_widget_queue_draw (GTK_WIDGET (plane));
}
static void
update_color (GtkColorPlane *plane,
int x,
int y)
{
GtkWidget *widget = GTK_WIDGET (plane);
double s, v;
s = CLAMP (1 - y * (1.0 / gtk_widget_get_height (widget)), 0, 1);
v = CLAMP (x * (1.0 / gtk_widget_get_width (widget)), 0, 1);
gtk_adjustment_set_value (plane->s_adj, s);
gtk_adjustment_set_value (plane->v_adj, v);
gtk_widget_queue_draw (widget);
}
static void
hold_action (GtkGestureLongPress *gesture,
double x,
double y,
GtkWidget *plane)
{
gtk_widget_activate_action (plane,
"color.edit",
"s", gtk_widget_get_name (plane));
}
static void
sv_move (GtkColorPlane *plane,
double ds,
double dv)
{
double s, v;
s = gtk_adjustment_get_value (plane->s_adj);
v = gtk_adjustment_get_value (plane->v_adj);
if (s + ds > 1)
{
if (s < 1)
s = 1;
else
goto error;
}
else if (s + ds < 0)
{
if (s > 0)
s = 0;
else
goto error;
}
else
{
s += ds;
}
if (v + dv > 1)
{
if (v < 1)
v = 1;
else
goto error;
}
else if (v + dv < 0)
{
if (v > 0)
v = 0;
else
goto error;
}
else
{
v += dv;
}
gtk_adjustment_set_value (plane->s_adj, s);
gtk_adjustment_set_value (plane->v_adj, v);
return;
error:
gtk_widget_error_bell (GTK_WIDGET (plane));
}
static gboolean
key_controller_key_pressed (GtkEventControllerKey *controller,
guint keyval,
guint keycode,
GdkModifierType state,
GtkWidget *widget)
{
GtkColorPlane *plane = GTK_COLOR_PLANE (widget);
double step;
if ((state & GDK_ALT_MASK) != 0)
step = 0.1;
else
step = 0.01;
if (keyval == GDK_KEY_Up ||
keyval == GDK_KEY_KP_Up)
sv_move (plane, step, 0);
else if (keyval == GDK_KEY_Down ||
keyval == GDK_KEY_KP_Down)
sv_move (plane, -step, 0);
else if (keyval == GDK_KEY_Left ||
keyval == GDK_KEY_KP_Left)
sv_move (plane, 0, -step);
else if (keyval == GDK_KEY_Right ||
keyval == GDK_KEY_KP_Right)
sv_move (plane, 0, step);
else
return FALSE;
return TRUE;
}
static void
plane_drag_gesture_begin (GtkGestureDrag *gesture,
double start_x,
double start_y,
GtkWidget *plane)
{
guint button;
button = gtk_gesture_single_get_current_button (GTK_GESTURE_SINGLE (gesture));
if (button == GDK_BUTTON_SECONDARY)
{
gtk_widget_activate_action (plane,
"color.edit",
"s", gtk_widget_get_name (plane));
}
if (button != GDK_BUTTON_PRIMARY)
{
gtk_gesture_set_state (GTK_GESTURE (gesture), GTK_EVENT_SEQUENCE_DENIED);
return;
}
set_cross_cursor (plane, TRUE);
update_color (GTK_COLOR_PLANE (plane), start_x, start_y);
gtk_widget_grab_focus (plane);
gtk_gesture_set_state (GTK_GESTURE (gesture), GTK_EVENT_SEQUENCE_CLAIMED);
}
static void
plane_drag_gesture_update (GtkGestureDrag *gesture,
double offset_x,
double offset_y,
GtkColorPlane *plane)
{
double start_x, start_y;
gtk_gesture_drag_get_start_point (GTK_GESTURE_DRAG (gesture),
&start_x, &start_y);
update_color (plane, start_x + offset_x, start_y + offset_y);
}
static void
plane_drag_gesture_end (GtkGestureDrag *gesture,
double offset_x,
double offset_y,
GtkColorPlane *plane)
{
set_cross_cursor (GTK_WIDGET (plane), FALSE);
}
static void
gtk_color_plane_init (GtkColorPlane *plane)
{
GtkEventController *controller;
GtkGesture *gesture;
GtkShortcutTrigger *trigger;
GtkShortcutAction *action;
GtkShortcut *shortcut;
gtk_widget_set_focusable (GTK_WIDGET (plane), TRUE);
gesture = gtk_gesture_drag_new ();
g_signal_connect (gesture, "drag-begin",
G_CALLBACK (plane_drag_gesture_begin), plane);
g_signal_connect (gesture, "drag-update",
G_CALLBACK (plane_drag_gesture_update), plane);
g_signal_connect (gesture, "drag-end",
G_CALLBACK (plane_drag_gesture_end), plane);
gtk_gesture_single_set_button (GTK_GESTURE_SINGLE (gesture), 0);
gtk_widget_add_controller (GTK_WIDGET (plane), GTK_EVENT_CONTROLLER (gesture));
gesture = gtk_gesture_long_press_new ();
g_signal_connect (gesture, "pressed",
G_CALLBACK (hold_action), plane);
gtk_gesture_single_set_touch_only (GTK_GESTURE_SINGLE (gesture),
TRUE);
gtk_widget_add_controller (GTK_WIDGET (plane), GTK_EVENT_CONTROLLER (gesture));
controller = gtk_event_controller_key_new ();
g_signal_connect (controller, "key-pressed",
G_CALLBACK (key_controller_key_pressed), plane);
gtk_widget_add_controller (GTK_WIDGET (plane), controller);
controller = gtk_shortcut_controller_new ();
trigger = gtk_alternative_trigger_new (gtk_keyval_trigger_new (GDK_KEY_F10, GDK_SHIFT_MASK),
gtk_keyval_trigger_new (GDK_KEY_Menu, 0));
action = gtk_named_action_new ("color.edit");
shortcut = gtk_shortcut_new_with_arguments (trigger, action, "s", "sv");
gtk_shortcut_controller_add_shortcut (GTK_SHORTCUT_CONTROLLER (controller), shortcut);
gtk_widget_add_controller (GTK_WIDGET (plane), controller);
}
static void
plane_finalize (GObject *object)
{
GtkColorPlane *plane = GTK_COLOR_PLANE (object);
g_clear_object (&plane->texture);
g_clear_object (&plane->h_adj);
g_clear_object (&plane->s_adj);
g_clear_object (&plane->v_adj);
G_OBJECT_CLASS (gtk_color_plane_parent_class)->finalize (object);
}
static void
plane_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GtkColorPlane *plane = GTK_COLOR_PLANE (object);
GtkAdjustment *adjustment;
/* Construct only properties can only be set once, these are created
* only in order to be properly buildable from gtkcoloreditor.ui
*/
switch (prop_id)
{
case PROP_H_ADJUSTMENT:
adjustment = g_value_get_object (value);
if (adjustment)
{
plane->h_adj = g_object_ref_sink (adjustment);
g_signal_connect_swapped (adjustment, "value-changed", G_CALLBACK (h_changed), plane);
}
break;
case PROP_S_ADJUSTMENT:
adjustment = g_value_get_object (value);
if (adjustment)
{
plane->s_adj = g_object_ref_sink (adjustment);
g_signal_connect_swapped (adjustment, "value-changed", G_CALLBACK (sv_changed), plane);
}
break;
case PROP_V_ADJUSTMENT:
adjustment = g_value_get_object (value);
if (adjustment)
{
plane->v_adj = g_object_ref_sink (adjustment);
g_signal_connect_swapped (adjustment, "value-changed", G_CALLBACK (sv_changed), plane);
}
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gtk_color_plane_class_init (GtkColorPlaneClass *class)
{
GObjectClass *object_class = G_OBJECT_CLASS (class);
GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (class);
object_class->finalize = plane_finalize;
object_class->set_property = plane_set_property;
widget_class->snapshot = plane_snapshot;
widget_class->size_allocate = plane_size_allocate;
widget_class->realize = plane_realize;
widget_class->unrealize = plane_unrealize;
g_object_class_install_property (object_class,
PROP_H_ADJUSTMENT,
g_param_spec_object ("h-adjustment",
"Hue Adjustment",
"Hue Adjustment",
GTK_TYPE_ADJUSTMENT,
GTK_PARAM_WRITABLE |
G_PARAM_CONSTRUCT_ONLY));
g_object_class_install_property (object_class,
PROP_S_ADJUSTMENT,
g_param_spec_object ("s-adjustment",
"Saturation Adjustment",
"Saturation Adjustment",
GTK_TYPE_ADJUSTMENT,
GTK_PARAM_WRITABLE |
G_PARAM_CONSTRUCT_ONLY));
g_object_class_install_property (object_class,
PROP_V_ADJUSTMENT,
g_param_spec_object ("v-adjustment",
"Value Adjustment",
"Value Adjustment",
GTK_TYPE_ADJUSTMENT,
GTK_PARAM_WRITABLE |
G_PARAM_CONSTRUCT_ONLY));
gtk_widget_class_set_css_name (widget_class, "plane");
}
GtkWidget *
gtk_color_plane_new (GtkAdjustment *h_adj,
GtkAdjustment *s_adj,
GtkAdjustment *v_adj)
{
return g_object_new (GTK_TYPE_COLOR_PLANE,
"h-adjustment", h_adj,
"s-adjustment", s_adj,
"v-adjustment", v_adj,
NULL);
}