gtk/demos/gtk-demo/event_axes.c
2016-04-08 17:34:29 +02:00

536 lines
14 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;
GdkDeviceTool *last_tool;
gdouble *axes;
GdkRGBA color;
gdouble x;
gdouble y;
} AxesInfo;
typedef struct {
GHashTable *pointer_info; /* GdkDevice -> AxesInfo */
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 EventData *
event_data_new (void)
{
EventData *data;
data = g_new0 (EventData, 1);
data->pointer_info = g_hash_table_new_full (NULL, NULL, NULL,
(GDestroyNotify) g_free);
data->touch_info = g_hash_table_new_full (NULL, NULL, NULL,
(GDestroyNotify) g_free);
return data;
}
static void
event_data_free (EventData *data)
{
g_hash_table_destroy (data->pointer_info);
g_hash_table_destroy (data->touch_info);
g_free (data);
}
static void
update_axes_from_event (GdkEvent *event,
EventData *data)
{
GdkDevice *device, *source_device;
GdkEventSequence *sequence;
GdkDeviceTool *tool;
gdouble x, y;
AxesInfo *info;
device = gdk_event_get_device (event);
source_device = gdk_event_get_source_device (event);
sequence = gdk_event_get_event_sequence (event);
tool = gdk_event_get_device_tool (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)
{
g_hash_table_remove (data->pointer_info, device);
return;
}
if (!sequence)
{
info = g_hash_table_lookup (data->pointer_info, device);
if (!info)
{
info = axes_info_new ();
g_hash_table_insert (data->pointer_info, device, 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;
if (info->last_tool != tool)
info->last_tool = tool;
g_clear_pointer (&info->axes, g_free);
if (event->type == GDK_TOUCH_BEGIN ||
event->type == GDK_TOUCH_UPDATE)
{
if (sequence && event->touch.emulating_pointer)
g_hash_table_remove (data->pointer_info, device);
}
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, distance, wheel, rotation, slider;
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_DISTANCE)
{
double dashes[] = { 5.0, 5.0 };
cairo_text_extents_t extents;
gdk_device_get_axis (info->last_source, info->axes, GDK_AXIS_DISTANCE,
&distance);
cairo_save (cr);
cairo_move_to (cr, distance * 100, 0);
cairo_set_source_rgb (cr, 0.0, 0.0, 0.0);
cairo_set_dash (cr, dashes, 2, 0.0);
cairo_arc (cr, 0, 0, distance * 100, 0, 2 * G_PI);
cairo_stroke (cr);
cairo_move_to (cr, 0, -distance * 100);
cairo_text_extents (cr, "Distance", &extents);
cairo_rel_move_to (cr, -extents.width / 2, 0);
cairo_show_text (cr, "Distance");
cairo_move_to (cr, 0, 0);
cairo_restore (cr);
}
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);
}
if (axes & GDK_AXIS_FLAG_ROTATION)
{
gdk_device_get_axis (info->last_source, info->axes, GDK_AXIS_ROTATION,
&rotation);
rotation *= 2 * G_PI;
cairo_save (cr);
cairo_rotate (cr, - G_PI / 2);
cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);
cairo_set_line_width (cr, 5);
cairo_new_sub_path (cr);
cairo_arc (cr, 0, 0, 100, 0, rotation);
cairo_stroke (cr);
cairo_restore (cr);
}
if (axes & GDK_AXIS_FLAG_SLIDER)
{
cairo_pattern_t *pattern, *mask;
gdk_device_get_axis (info->last_source, info->axes, GDK_AXIS_SLIDER,
&slider);
cairo_save (cr);
cairo_move_to (cr, 0, -10);
cairo_rel_line_to (cr, 0, -50);
cairo_rel_line_to (cr, 10, 0);
cairo_rel_line_to (cr, -5, 50);
cairo_close_path (cr);
cairo_clip_preserve (cr);
pattern = cairo_pattern_create_linear (0, -10, 0, -60);
cairo_pattern_add_color_stop_rgb (pattern, 0, 0, 1, 0);
cairo_pattern_add_color_stop_rgb (pattern, 1, 1, 0, 0);
cairo_set_source (cr, pattern);
cairo_pattern_destroy (pattern);
mask = cairo_pattern_create_linear (0, -10, 0, -60);
cairo_pattern_add_color_stop_rgba (mask, 0, 0, 0, 0, 1);
cairo_pattern_add_color_stop_rgba (mask, slider, 0, 0, 0, 1);
cairo_pattern_add_color_stop_rgba (mask, slider, 0, 0, 0, 0);
cairo_pattern_add_color_stop_rgba (mask, 1, 0, 0, 0, 0);
cairo_mask (cr, mask);
cairo_pattern_destroy (mask);
cairo_set_source_rgb (cr, 0, 0, 0);
cairo_stroke (cr);
cairo_restore (cr);
}
cairo_restore (cr);
}
static const gchar *
tool_type_to_string (GdkDeviceToolType tool_type)
{
switch (tool_type)
{
case GDK_DEVICE_TOOL_TYPE_PEN:
return "Pen";
case GDK_DEVICE_TOOL_TYPE_ERASER:
return "Eraser";
case GDK_DEVICE_TOOL_TYPE_BRUSH:
return "Brush";
case GDK_DEVICE_TOOL_TYPE_PENCIL:
return "Pencil";
case GDK_DEVICE_TOOL_TYPE_AIRBRUSH:
return "Airbrush";
case GDK_DEVICE_TOOL_TYPE_MOUSE:
return "Mouse";
case GDK_DEVICE_TOOL_TYPE_LENS:
return "Lens cursor";
case GDK_DEVICE_TOOL_TYPE_UNKNOWN:
default:
return "Unknown";
}
}
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));
if (info->last_tool)
{
const gchar *tool_type;
guint64 serial;
tool_type = tool_type_to_string (gdk_device_tool_get_tool_type (info->last_tool));
serial = gdk_device_tool_get_serial (info->last_tool);
g_string_append_printf (string, "\nTool: %s", tool_type);
if (serial != 0)
g_string_append_printf (string, ", Serial: %lx", serial);
}
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 *info;
GHashTableIter iter;
gpointer key, value;
gint y = 0;
gtk_widget_get_allocation (widget, &allocation);
/* Draw Abs info */
g_hash_table_iter_init (&iter, data->pointer_info);
while (g_hash_table_iter_next (&iter, NULL, &value))
{
info = value;
draw_axes_info (cr, info, &allocation);
}
g_hash_table_iter_init (&iter, data->touch_info);
while (g_hash_table_iter_next (&iter, NULL, &value))
{
info = value;
draw_axes_info (cr, info, &allocation);
}
/* Draw name, color legend and misc data */
g_hash_table_iter_init (&iter, data->pointer_info);
while (g_hash_table_iter_next (&iter, NULL, &value))
{
info = value;
draw_device_info (widget, cr, NULL, &y, info);
}
g_hash_table_iter_init (&iter, data->touch_info);
while (g_hash_table_iter_next (&iter, &key, &value))
{
info = value;
draw_device_info (widget, cr, key, &y, 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_set_support_multidevice (box, TRUE);
gtk_widget_add_events (box,
GDK_POINTER_MOTION_MASK |
GDK_BUTTON_PRESS_MASK |
GDK_BUTTON_RELEASE_MASK |
GDK_SMOOTH_SCROLL_MASK |
GDK_ENTER_NOTIFY_MASK |
GDK_LEAVE_NOTIFY_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;
}