Learning_GTK4_tree/demos/gtk-demo/fontplane.c

286 lines
8.1 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 "fontplane.h"
enum {
PROP_0,
PROP_WEIGHT_ADJUSTMENT,
PROP_WIDTH_ADJUSTMENT
};
G_DEFINE_TYPE (GtkFontPlane, gtk_font_plane, GTK_TYPE_WIDGET)
static double
adjustment_get_normalized_value (GtkAdjustment *adj)
{
return (gtk_adjustment_get_value (adj) - gtk_adjustment_get_lower (adj)) /
(gtk_adjustment_get_upper (adj) - gtk_adjustment_get_lower (adj));
}
static void
val_to_xy (GtkFontPlane *plane,
int *x,
int *y)
{
double u, v;
int width, height;
width = gtk_widget_get_width (GTK_WIDGET (plane));
height = gtk_widget_get_height (GTK_WIDGET (plane));
u = adjustment_get_normalized_value (plane->width_adj);
v = adjustment_get_normalized_value (plane->weight_adj);
*x = CLAMP (width * u, 0, width - 1);
*y = CLAMP (height * (1 - v), 0, height - 1);
}
static void
plane_snapshot (GtkWidget *widget,
GtkSnapshot *snapshot)
{
GtkFontPlane *plane = GTK_FONT_PLANE (widget);
int x, y;
int width, height;
cairo_t *cr;
val_to_xy (plane, &x, &y);
width = gtk_widget_get_width (widget);
height = gtk_widget_get_height (widget);
cr = gtk_snapshot_append_cairo (snapshot,
&GRAPHENE_RECT_INIT (0, 0, width, height));
cairo_set_source_rgb (cr, 0, 0, 0);
cairo_rectangle (cr, 0, 0, width, height);
cairo_paint (cr);
cairo_move_to (cr, 0, y + 0.5);
cairo_line_to (cr, width, y + 0.5);
cairo_move_to (cr, x + 0.5, 0);
cairo_line_to (cr, x + 0.5, height);
if (gtk_widget_has_visible_focus (widget))
{
cairo_set_line_width (cr, 3.0);
cairo_set_source_rgba (cr, 1.0, 1.0, 1.0, 0.6);
cairo_stroke_preserve (cr);
cairo_set_line_width (cr, 1.0);
cairo_set_source_rgba (cr, 0.0, 0.0, 0.0, 0.8);
cairo_stroke (cr);
}
else
{
cairo_set_line_width (cr, 1.0);
cairo_set_source_rgba (cr, 0.8, 0.8, 0.8, 0.8);
cairo_stroke (cr);
}
cairo_destroy (cr);
}
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
adj_changed (GtkFontPlane *plane)
{
gtk_widget_queue_draw (GTK_WIDGET (plane));
}
static void
adjustment_set_normalized_value (GtkAdjustment *adj,
double val)
{
gtk_adjustment_set_value (adj,
gtk_adjustment_get_lower (adj) +
val * (gtk_adjustment_get_upper (adj) - gtk_adjustment_get_lower (adj)));
}
static void
update_value (GtkFontPlane *plane,
int x,
int y)
{
GtkWidget *widget = GTK_WIDGET (plane);
double u, v;
u = CLAMP (x * (1.0 / gtk_widget_get_width (widget)), 0, 1);
v = CLAMP (1 - y * (1.0 / gtk_widget_get_height (widget)), 0, 1);
adjustment_set_normalized_value (plane->width_adj, u);
adjustment_set_normalized_value (plane->weight_adj, v);
gtk_widget_queue_draw (widget);
}
static void
plane_drag_gesture_begin (GtkGestureDrag *gesture,
double start_x,
double start_y,
GtkFontPlane *plane)
{
guint button;
button = gtk_gesture_single_get_current_button (GTK_GESTURE_SINGLE (gesture));
if (button != GDK_BUTTON_PRIMARY)
{
gtk_gesture_set_state (GTK_GESTURE (gesture), GTK_EVENT_SEQUENCE_DENIED);
return;
}
set_cross_cursor (GTK_WIDGET (plane), TRUE);
update_value (plane, start_x, start_y);
gtk_widget_grab_focus (GTK_WIDGET (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,
GtkFontPlane *plane)
{
double start_x, start_y;
gtk_gesture_drag_get_start_point (GTK_GESTURE_DRAG (gesture),
&start_x, &start_y);
update_value (plane, start_x + offset_x, start_y + offset_y);
}
static void
plane_drag_gesture_end (GtkGestureDrag *gesture,
double offset_x,
double offset_y,
GtkFontPlane *plane)
{
set_cross_cursor (GTK_WIDGET (plane), FALSE);
}
static void
gtk_font_plane_init (GtkFontPlane *plane)
{
GtkGesture *gesture;
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));
}
static void
plane_finalize (GObject *object)
{
GtkFontPlane *plane = GTK_FONT_PLANE (object);
g_clear_object (&plane->weight_adj);
g_clear_object (&plane->width_adj);
G_OBJECT_CLASS (gtk_font_plane_parent_class)->finalize (object);
}
static void
plane_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GtkFontPlane *plane = GTK_FONT_PLANE (object);
GtkAdjustment *adjustment;
switch (prop_id)
{
case PROP_WEIGHT_ADJUSTMENT:
adjustment = GTK_ADJUSTMENT (g_value_get_object (value));
if (adjustment)
{
plane->weight_adj = g_object_ref_sink (adjustment);
g_signal_connect_swapped (adjustment, "value-changed", G_CALLBACK (adj_changed), plane);
}
break;
case PROP_WIDTH_ADJUSTMENT:
adjustment = GTK_ADJUSTMENT (g_value_get_object (value));
if (adjustment)
{
plane->width_adj = g_object_ref_sink (adjustment);
g_signal_connect_swapped (adjustment, "value-changed", G_CALLBACK (adj_changed), plane);
}
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gtk_font_plane_class_init (GtkFontPlaneClass *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;
g_object_class_install_property (object_class,
PROP_WEIGHT_ADJUSTMENT,
g_param_spec_object ("weight-adjustment",
NULL,
NULL,
GTK_TYPE_ADJUSTMENT,
G_PARAM_WRITABLE |
G_PARAM_CONSTRUCT_ONLY));
g_object_class_install_property (object_class,
PROP_WIDTH_ADJUSTMENT,
g_param_spec_object ("width-adjustment",
NULL,
NULL,
GTK_TYPE_ADJUSTMENT,
G_PARAM_WRITABLE |
G_PARAM_CONSTRUCT_ONLY));
}
GtkWidget *
gtk_font_plane_new (GtkAdjustment *weight_adj,
GtkAdjustment *width_adj)
{
return g_object_new (GTK_TYPE_FONT_PLANE,
"weight-adjustment", weight_adj,
"width-adjustment", width_adj,
NULL);
}