gtk2/demos/gtk-demo/event_axes.c
2018-06-10 21:20:59 +00:00

667 lines
17 KiB
C

/* Touch and Drawing Tablets
*
* Demonstrates advanced handling of event information from exotic
* input devices.
*
* On one hand, this snippet demonstrates management of drawing tablets,
* those contain additional information for the pointer other than
* X/Y coordinates. Tablet pads events are mapped to actions, which
* are both defined and interpreted by the application.
*
* 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 <glib/gi18n.h>
#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 GtkPadActionEntry pad_actions[] = {
{ GTK_PAD_ACTION_BUTTON, 1, -1, N_("Nuclear strike"), "pad.nuke" },
{ GTK_PAD_ACTION_BUTTON, 2, -1, N_("Release siberian methane reserves"), "pad.heat" },
{ GTK_PAD_ACTION_BUTTON, 3, -1, N_("Release solar flare"), "pad.fry" },
{ GTK_PAD_ACTION_BUTTON, 4, -1, N_("De-stabilize Oort cloud"), "pad.fall" },
{ GTK_PAD_ACTION_BUTTON, 5, -1, N_("Ignite WR-104"), "pad.burst" },
{ GTK_PAD_ACTION_BUTTON, 6, -1, N_("Lart whoever asks about this button"), "pad.lart" },
{ GTK_PAD_ACTION_RING, -1, -1, N_("Earth axial tilt"), "pad.tilt" },
{ GTK_PAD_ACTION_STRIP, -1, -1, N_("Extent of weak nuclear force"), "pad.dissolve" },
};
static const gchar *pad_action_results[] = {
"",
"",
"",
"",
"",
"💫",
"",
""
};
static guint cur_color = 0;
static guint pad_action_timeout_id = 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;
GdkEventType type;
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);
type = gdk_event_get_event_type (event);
if (type == GDK_TOUCH_END ||
type == GDK_TOUCH_CANCEL)
{
g_hash_table_remove (data->touch_info, sequence);
return;
}
else if (type == GDK_LEAVE_NOTIFY)
{
g_hash_table_remove (data->pointer_info, device);
return;
}
if (!source_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 (type == GDK_TOUCH_BEGIN ||
type == GDK_TOUCH_UPDATE)
{
gboolean emulating_pointer;
gdk_event_get_touch_emulating_pointer (event, &emulating_pointer);
if (sequence && emulating_pointer)
g_hash_table_remove (data->pointer_info, device);
}
if (type == GDK_MOTION_NOTIFY ||
type == GDK_BUTTON_PRESS ||
type == GDK_BUTTON_RELEASE)
{
gdouble *axes;
guint n_axes;
gdk_event_get_axes (event, &axes, &n_axes);
info->axes = g_memdup (axes, sizeof (double) * n_axes);
}
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,
int width,
int height)
{
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, width, info->y);
cairo_move_to (cr, info->x, 0);
cairo_line_to (cr, info->x, 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: %" G_GINT64_MODIFIER "x", 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 void
draw_cb (GtkDrawingArea *da,
cairo_t *cr,
int width,
int height,
gpointer user_data)
{
GtkWidget *widget = GTK_WIDGET (da);
EventData *data = user_data;
AxesInfo *info;
GHashTableIter iter;
gpointer key, value;
gint y = 0;
/* 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, width, height);
}
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, width, height);
}
/* 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);
}
}
static void
update_label_text (GtkWidget *label,
const gchar *text)
{
gchar *markup = NULL;
if (text)
markup = g_strdup_printf ("<span font='48.0'>%s</span>", text);
gtk_label_set_markup (GTK_LABEL (label), markup);
g_free (markup);
}
static gboolean
reset_label_text_timeout_cb (gpointer user_data)
{
GtkWidget *label = user_data;
update_label_text (label, NULL);
pad_action_timeout_id = 0;
return G_SOURCE_REMOVE;
}
static void
update_label_and_timeout (GtkWidget *label,
const gchar *text)
{
if (pad_action_timeout_id)
g_source_remove (pad_action_timeout_id);
update_label_text (label, text);
pad_action_timeout_id = g_timeout_add (200, reset_label_text_timeout_cb, label);
}
static void
on_action_activate (GSimpleAction *action,
GVariant *parameter,
gpointer user_data)
{
GtkWidget *label = user_data;
const gchar *result;
gchar *str;
result = g_object_get_data (G_OBJECT (action), "action-result");
if (!parameter)
update_label_and_timeout (label, result);
else
{
str = g_strdup_printf ("%s %.2f", result, g_variant_get_double (parameter));
update_label_and_timeout (label, str);
g_free (str);
}
}
static void
init_pad_controller (GtkWidget *window,
GtkWidget *label)
{
GtkPadController *pad_controller;
GSimpleActionGroup *action_group;
GSimpleAction *action;
gint i;
action_group = g_simple_action_group_new ();
pad_controller = gtk_pad_controller_new (G_ACTION_GROUP (action_group),
NULL);
for (i = 0; i < G_N_ELEMENTS (pad_actions); i++)
{
if (pad_actions[i].type == GTK_PAD_ACTION_BUTTON)
{
action = g_simple_action_new (pad_actions[i].action_name, NULL);
}
else
{
action = g_simple_action_new_stateful (pad_actions[i].action_name,
G_VARIANT_TYPE_DOUBLE, NULL);
}
g_signal_connect (action, "activate",
G_CALLBACK (on_action_activate), label);
g_object_set_data (G_OBJECT (action), "action-result",
(gpointer) pad_action_results[i]);
g_action_map_add_action (G_ACTION_MAP (action_group), G_ACTION (action));
g_object_unref (action);
}
gtk_pad_controller_set_action_entries (pad_controller, pad_actions,
G_N_ELEMENTS (pad_actions));
gtk_widget_add_controller (window, GTK_EVENT_CONTROLLER (pad_controller));
g_object_unref (action_group);
}
GtkWidget *
do_event_axes (GtkWidget *toplevel)
{
static GtkWidget *window = NULL;
EventData *event_data;
GtkWidget *label;
GtkWidget *overlay;
GtkWidget *da;
if (!window)
{
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
gtk_window_set_title (GTK_WINDOW (window), "Touch and Drawing Tablets");
g_signal_connect (window, "destroy",
G_CALLBACK (gtk_widget_destroyed), &window);
gtk_widget_set_support_multidevice (window, TRUE);
event_data = event_data_new ();
g_object_set_data_full (G_OBJECT (window), "gtk-demo-event-data",
event_data, (GDestroyNotify) event_data_free);
da = gtk_drawing_area_new ();
gtk_drawing_area_set_content_width (GTK_DRAWING_AREA (da), 400);
gtk_drawing_area_set_content_height (GTK_DRAWING_AREA (da), 400);
gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (da), draw_cb, event_data, NULL);
gtk_widget_set_can_focus (da, TRUE);
gtk_widget_grab_focus (da);
g_signal_connect (da, "event",
G_CALLBACK (event_cb), event_data);
label = gtk_label_new ("");
gtk_widget_set_halign (label, GTK_ALIGN_START);
gtk_widget_set_valign (label, GTK_ALIGN_START);
gtk_label_set_use_markup (GTK_LABEL (label), TRUE);
overlay = gtk_overlay_new ();
gtk_container_add (GTK_CONTAINER (window), overlay);
gtk_container_add (GTK_CONTAINER (overlay), da);
gtk_overlay_add_overlay (GTK_OVERLAY (overlay), label);
init_pad_controller (da, label);
}
if (!gtk_widget_get_visible (window))
gtk_widget_show (window);
else
gtk_widget_destroy (window);
return window;
}