gtk/demos/gtk-demo/event_axes.c
Stephen Chandler Paul 6c2a078bf2 gtk-demo: Use GdkAxisUse instead of axis labels
Axis labels are very X specific, and are not really possible to port to other
backends such as Wayland. As such, it makes more sense to use GdkAxisUse and
GdkAxisUseFlag in order to determine the axis capabilities of a device and draw
their axes.

Signed-off-by: Stephen Chandler Paul <thatslyude@gmail.com>
2016-04-06 15:43:29 +02:00

404 lines
9.6 KiB
C

/* Event Axes
*
* Demonstrates advanced handling of event information from exotic
* input devices.
*
* On one hand, this snippet demonstrates management of input axes,
* those contain additional information for the pointer other than
* X/Y coordinates.
*
* Input axes are dependent on hardware devices, on linux/unix you
* can see the device axes through xinput list <device>. Each time
* a different hardware device is used to move the pointer, the
* master device will be updated to match the axes it provides,
* these changes can be tracked through GdkDevice::changed, or
* checking gdk_event_get_source_device().
*
* On the other hand, this demo handles basic multitouch events,
* each event coming from an specific touchpoint will contain a
* GdkEventSequence that's unique for its lifetime, so multiple
* touchpoints can be tracked.
*/
#include <gtk/gtk.h>
typedef struct {
GdkDevice *last_source;
gdouble *axes;
GdkRGBA color;
gdouble x;
gdouble y;
} AxesInfo;
typedef struct {
AxesInfo *pointer_info;
GHashTable *touch_info; /* GdkEventSequence -> AxesInfo */
} EventData;
const gchar *colors[] = {
"black",
"orchid",
"fuchsia",
"indigo",
"thistle",
"sienna",
"azure",
"plum",
"lime",
"navy",
"maroon",
"burlywood"
};
static guint cur_color = 0;
static AxesInfo *
axes_info_new (void)
{
AxesInfo *info;
info = g_new0 (AxesInfo, 1);
gdk_rgba_parse (&info->color, colors[cur_color]);
cur_color = (cur_color + 1) % G_N_ELEMENTS (colors);
return info;
}
static void
axes_info_free (AxesInfo *info)
{
g_free (info);
}
static EventData *
event_data_new (void)
{
EventData *data;
data = g_new0 (EventData, 1);
data->touch_info = g_hash_table_new_full (NULL, NULL, NULL,
(GDestroyNotify) axes_info_free);
return data;
}
static void
event_data_free (EventData *data)
{
if (data->pointer_info)
axes_info_free (data->pointer_info);
g_hash_table_destroy (data->touch_info);
g_free (data);
}
static void
update_axes_from_event (GdkEvent *event,
EventData *data)
{
GdkDevice *source_device;
GdkEventSequence *sequence;
gdouble x, y;
AxesInfo *info;
source_device = gdk_event_get_source_device (event);
sequence = gdk_event_get_event_sequence (event);
if (event->type == GDK_TOUCH_END ||
event->type == GDK_TOUCH_CANCEL)
{
g_hash_table_remove (data->touch_info, sequence);
return;
}
else if (event->type == GDK_LEAVE_NOTIFY)
{
if (data->pointer_info)
axes_info_free (data->pointer_info);
data->pointer_info = NULL;
return;
}
if (!sequence)
{
if (!data->pointer_info)
data->pointer_info = axes_info_new ();
info = data->pointer_info;
}
else
{
info = g_hash_table_lookup (data->touch_info, sequence);
if (!info)
{
info = axes_info_new ();
g_hash_table_insert (data->touch_info, sequence, info);
}
}
if (info->last_source != source_device)
info->last_source = source_device;
g_clear_pointer (&info->axes, g_free);
if (event->type == GDK_TOUCH_BEGIN ||
event->type == GDK_TOUCH_UPDATE)
{
if (sequence && event->touch.emulating_pointer)
{
if (data->pointer_info)
axes_info_free (data->pointer_info);
data->pointer_info = NULL;
}
}
if (event->type == GDK_MOTION_NOTIFY)
{
info->axes =
g_memdup (event->motion.axes,
sizeof (gdouble) * gdk_device_get_n_axes (source_device));
}
else if (event->type == GDK_BUTTON_PRESS ||
event->type == GDK_BUTTON_RELEASE)
{
info->axes =
g_memdup (event->button.axes,
sizeof (gdouble) * gdk_device_get_n_axes (source_device));
}
if (gdk_event_get_coords (event, &x, &y))
{
info->x = x;
info->y = y;
}
}
static gboolean
event_cb (GtkWidget *widget,
GdkEvent *event,
gpointer user_data)
{
update_axes_from_event (event, user_data);
gtk_widget_queue_draw (widget);
return FALSE;
}
static void
render_arrow (cairo_t *cr,
gdouble x_diff,
gdouble y_diff,
const gchar *label)
{
cairo_save (cr);
cairo_set_source_rgb (cr, 0, 0, 0);
cairo_new_path (cr);
cairo_move_to (cr, 0, 0);
cairo_line_to (cr, x_diff, y_diff);
cairo_stroke (cr);
cairo_move_to (cr, x_diff, y_diff);
cairo_show_text (cr, label);
cairo_restore (cr);
}
static void
draw_axes_info (cairo_t *cr,
AxesInfo *info,
GtkAllocation *allocation)
{
gdouble pressure, tilt_x, tilt_y, wheel;
GdkAxisFlags axes = gdk_device_get_axes (info->last_source);
cairo_save (cr);
cairo_set_line_width (cr, 1);
gdk_cairo_set_source_rgba (cr, &info->color);
cairo_move_to (cr, 0, info->y);
cairo_line_to (cr, allocation->width, info->y);
cairo_move_to (cr, info->x, 0);
cairo_line_to (cr, info->x, allocation->height);
cairo_stroke (cr);
cairo_translate (cr, info->x, info->y);
if (!info->axes)
{
cairo_restore (cr);
return;
}
if (axes & GDK_AXIS_FLAG_PRESSURE)
{
cairo_pattern_t *pattern;
gdk_device_get_axis (info->last_source, info->axes, GDK_AXIS_PRESSURE,
&pressure);
pattern = cairo_pattern_create_radial (0, 0, 0, 0, 0, 100);
cairo_pattern_add_color_stop_rgba (pattern, pressure, 1, 0, 0, pressure);
cairo_pattern_add_color_stop_rgba (pattern, 1, 0, 0, 1, 0);
cairo_set_source (cr, pattern);
cairo_arc (cr, 0, 0, 100, 0, 2 * G_PI);
cairo_fill (cr);
cairo_pattern_destroy (pattern);
}
if (axes & GDK_AXIS_FLAG_XTILT &&
axes & GDK_AXIS_FLAG_YTILT)
{
gdk_device_get_axis (info->last_source, info->axes, GDK_AXIS_XTILT,
&tilt_x);
gdk_device_get_axis (info->last_source, info->axes, GDK_AXIS_YTILT,
&tilt_y);
render_arrow (cr, tilt_x * 100, tilt_y * 100, "Tilt");
}
if (axes & GDK_AXIS_FLAG_WHEEL)
{
gdk_device_get_axis (info->last_source, info->axes, GDK_AXIS_WHEEL,
&wheel);
cairo_save (cr);
cairo_set_line_width (cr, 10);
cairo_set_source_rgba (cr, 0, 0, 0, 0.5);
cairo_new_sub_path (cr);
cairo_arc (cr, 0, 0, 100, 0, wheel * 2 * G_PI);
cairo_stroke (cr);
cairo_restore (cr);
}
cairo_restore (cr);
}
static void
draw_device_info (GtkWidget *widget,
cairo_t *cr,
GdkEventSequence *sequence,
gint *y,
AxesInfo *info)
{
PangoLayout *layout;
GString *string;
gint height;
cairo_save (cr);
string = g_string_new (NULL);
g_string_append_printf (string, "Source: %s",
gdk_device_get_name (info->last_source));
if (sequence)
g_string_append_printf (string, "\nSequence: %d",
GPOINTER_TO_UINT (sequence));
cairo_move_to (cr, 10, *y);
layout = gtk_widget_create_pango_layout (widget, string->str);
pango_cairo_show_layout (cr, layout);
cairo_stroke (cr);
pango_layout_get_pixel_size (layout, NULL, &height);
gdk_cairo_set_source_rgba (cr, &info->color);
cairo_set_line_width (cr, 10);
cairo_move_to (cr, 0, *y);
*y = *y + height;
cairo_line_to (cr, 0, *y);
cairo_stroke (cr);
cairo_restore (cr);
g_object_unref (layout);
g_string_free (string, TRUE);
}
static gboolean
draw_cb (GtkWidget *widget,
cairo_t *cr,
gpointer user_data)
{
EventData *data = user_data;
GtkAllocation allocation;
AxesInfo *touch_info;
GHashTableIter iter;
gpointer key, value;
gint y = 0;
gtk_widget_get_allocation (widget, &allocation);
/* Draw Abs info */
if (data->pointer_info)
draw_axes_info (cr, data->pointer_info, &allocation);
g_hash_table_iter_init (&iter, data->touch_info);
while (g_hash_table_iter_next (&iter, NULL, &value))
{
touch_info = value;
draw_axes_info (cr, touch_info, &allocation);
}
/* Draw name, color legend and misc data */
if (data->pointer_info)
draw_device_info (widget, cr, NULL, &y, data->pointer_info);
g_hash_table_iter_init (&iter, data->touch_info);
while (g_hash_table_iter_next (&iter, &key, &value))
{
touch_info = value;
draw_device_info (widget, cr, key, &y, touch_info);
}
return FALSE;
}
GtkWidget *
do_event_axes (GtkWidget *toplevel)
{
static GtkWidget *window = NULL;
EventData *event_data;
GtkWidget *box;
if (!window)
{
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
gtk_window_set_title (GTK_WINDOW (window), "Event Axes");
gtk_window_set_default_size (GTK_WINDOW (window), 400, 400);
g_signal_connect (window, "destroy",
G_CALLBACK (gtk_widget_destroyed), &window);
box = gtk_event_box_new ();
gtk_container_add (GTK_CONTAINER (window), box);
gtk_widget_add_events (box,
GDK_POINTER_MOTION_MASK |
GDK_BUTTON_PRESS_MASK |
GDK_BUTTON_RELEASE_MASK |
GDK_SMOOTH_SCROLL_MASK |
GDK_TOUCH_MASK);
event_data = event_data_new ();
g_object_set_data_full (G_OBJECT (box), "gtk-demo-event-data",
event_data, (GDestroyNotify) event_data_free);
g_signal_connect (box, "event",
G_CALLBACK (event_cb), event_data);
g_signal_connect (box, "draw",
G_CALLBACK (draw_cb), event_data);
}
if (!gtk_widget_get_visible (window))
gtk_widget_show_all (window);
else
gtk_widget_destroy (window);
return window;
}