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/* Gestures
* #Keywords: GtkGesture
*
* Perform gestures on touchscreens and other input devices. This
* demo reacts to long presses and swipes from all devices, plus
* multi-touch rotate and zoom gestures.
*/
#include <gtk/gtk.h>
static GtkGesture *rotate = NULL;
static GtkGesture *zoom = NULL;
static double swipe_x = 0;
static double swipe_y = 0;
static gboolean long_pressed = FALSE;
static gboolean
touchpad_swipe_gesture_begin (GtkGesture *gesture,
GdkEventSequence *sequence,
GtkWidget *widget)
{
/* Disallow touchscreen events here */
if (sequence != NULL)
gtk_gesture_set_state (gesture, GTK_EVENT_SEQUENCE_DENIED);
return sequence == NULL;
}
static void
swipe_gesture_swept (GtkGestureSwipe *gesture,
double velocity_x,
double velocity_y,
GtkWidget *widget)
{
swipe_x = velocity_x / 10;
swipe_y = velocity_y / 10;
gtk_widget_queue_draw (widget);
}
static void
long_press_gesture_pressed (GtkGestureLongPress *gesture,
double x,
double y,
GtkWidget *widget)
{
long_pressed = TRUE;
gtk_widget_queue_draw (widget);
}
static void
long_press_gesture_end (GtkGesture *gesture,
GdkEventSequence *sequence,
GtkWidget *widget)
{
long_pressed = FALSE;
gtk_widget_queue_draw (widget);
}
static void
rotation_angle_changed (GtkGestureRotate *gesture,
double angle,
double delta,
GtkWidget *widget)
{
gtk_widget_queue_draw (widget);
}
static void
zoom_scale_changed (GtkGestureZoom *gesture,
double scale,
GtkWidget *widget)
{
gtk_widget_queue_draw (widget);
}
static void
drawing_area_draw (GtkDrawingArea *area,
cairo_t *cr,
int width,
int height,
gpointer data)
{
if (swipe_x != 0 || swipe_y != 0)
{
cairo_save (cr);
cairo_set_line_width (cr, 6);
cairo_move_to (cr, width / 2, height / 2);
cairo_rel_line_to (cr, swipe_x, swipe_y);
cairo_set_source_rgba (cr, 1, 0, 0, 0.5);
cairo_stroke (cr);
cairo_restore (cr);
}
if (gtk_gesture_is_recognized (rotate) || gtk_gesture_is_recognized (zoom))
{
cairo_pattern_t *pat;
cairo_matrix_t matrix;
double angle, scale;
double x_center, y_center;
gtk_gesture_get_bounding_box_center (GTK_GESTURE (zoom), &x_center, &y_center);
cairo_get_matrix (cr, &matrix);
cairo_matrix_translate (&matrix, x_center, y_center);
cairo_save (cr);
angle = gtk_gesture_rotate_get_angle_delta (GTK_GESTURE_ROTATE (rotate));
cairo_matrix_rotate (&matrix, angle);
scale = gtk_gesture_zoom_get_scale_delta (GTK_GESTURE_ZOOM (zoom));
cairo_matrix_scale (&matrix, scale, scale);
cairo_set_matrix (cr, &matrix);
cairo_rectangle (cr, -100, -100, 200, 200);
pat = cairo_pattern_create_linear (-100, 0, 200, 0);
cairo_pattern_add_color_stop_rgb (pat, 0, 0, 0, 1);
cairo_pattern_add_color_stop_rgb (pat, 1, 1, 0, 0);
cairo_set_source (cr, pat);
cairo_fill (cr);
cairo_restore (cr);
cairo_pattern_destroy (pat);
}
if (long_pressed)
{
cairo_save (cr);
cairo_arc (cr,
width / 2, height / 2,
50, 0, 2 * G_PI);
cairo_set_source_rgba (cr, 0, 1, 0, 0.5);
cairo_stroke (cr);
cairo_restore (cr);
}
}
GtkWidget *
do_gestures (GtkWidget *do_widget)
{
static GtkWidget *window = NULL;
GtkWidget *drawing_area;
GtkGesture *gesture;
if (!window)
{
window = gtk_window_new ();
gtk_window_set_default_size (GTK_WINDOW (window), 400, 400);
gtk_window_set_title (GTK_WINDOW (window), "Gestures");
g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
drawing_area = gtk_drawing_area_new ();
gtk_window_set_child (GTK_WINDOW (window), drawing_area);
gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (drawing_area),
drawing_area_draw,
NULL, NULL);
/* Swipe */
gesture = gtk_gesture_swipe_new ();
g_signal_connect (gesture, "swipe",
G_CALLBACK (swipe_gesture_swept), drawing_area);
gtk_event_controller_set_propagation_phase (GTK_EVENT_CONTROLLER (gesture),
GTK_PHASE_BUBBLE);
gtk_widget_add_controller (drawing_area, GTK_EVENT_CONTROLLER (gesture));
/* 3fg swipe for touchpads */
gesture = g_object_new (GTK_TYPE_GESTURE_SWIPE,
"n-points", 3,
NULL);
g_signal_connect (gesture, "begin",
G_CALLBACK (touchpad_swipe_gesture_begin), drawing_area);
g_signal_connect (gesture, "swipe",
G_CALLBACK (swipe_gesture_swept), drawing_area);
gtk_event_controller_set_propagation_phase (GTK_EVENT_CONTROLLER (gesture),
GTK_PHASE_BUBBLE);
gtk_widget_add_controller (drawing_area, GTK_EVENT_CONTROLLER (gesture));
/* Long press */
gesture = gtk_gesture_long_press_new ();
g_signal_connect (gesture, "pressed",
G_CALLBACK (long_press_gesture_pressed), drawing_area);
g_signal_connect (gesture, "end",
G_CALLBACK (long_press_gesture_end), drawing_area);
gtk_event_controller_set_propagation_phase (GTK_EVENT_CONTROLLER (gesture),
GTK_PHASE_BUBBLE);
gtk_widget_add_controller (drawing_area, GTK_EVENT_CONTROLLER (gesture));
/* Rotate */
rotate = gesture = gtk_gesture_rotate_new ();
g_signal_connect (gesture, "angle-changed",
G_CALLBACK (rotation_angle_changed), drawing_area);
gtk_event_controller_set_propagation_phase (GTK_EVENT_CONTROLLER (gesture),
GTK_PHASE_BUBBLE);
gtk_widget_add_controller (drawing_area, GTK_EVENT_CONTROLLER (gesture));
/* Zoom */
zoom = gesture = gtk_gesture_zoom_new ();
g_signal_connect (gesture, "scale-changed",
G_CALLBACK (zoom_scale_changed), drawing_area);
gtk_event_controller_set_propagation_phase (GTK_EVENT_CONTROLLER (gesture),
GTK_PHASE_BUBBLE);
gtk_widget_add_controller (drawing_area, GTK_EVENT_CONTROLLER (gesture));
}
if (!gtk_widget_get_visible (window))
gtk_widget_show (window);
else
gtk_window_destroy (GTK_WINDOW (window));
return window;
}
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