summaryrefslogtreecommitdiff
path: root/gtk/gtkgesturestylus.c
blob: 294fa293a326a91f993bde524bd0d3b77df0b929 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
/* GTK - The GIMP Toolkit
 * Copyright (C) 2017-2018, 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/>.
 *
 * Author(s): Carlos Garnacho <carlosg@gnome.org>
 */

/**
 * SECTION:gtkgesturestylus
 * @Short_description: Gesture for stylus input
 * @Title: GtkGestureStylus
 * @See_also: #GtkGesture, #GtkGestureSingle
 *
 * #GtkGestureStylus is a #GtkGesture implementation specific to stylus
 * input. The provided signals just provide the basic information
 */

#include "config.h"
#include "gtkgesturestylus.h"
#include "gtkgesturestylusprivate.h"
#include "gtkprivate.h"
#include "gtkintl.h"
#include "gtkmain.h"

G_DEFINE_TYPE (GtkGestureStylus, gtk_gesture_stylus, GTK_TYPE_GESTURE_SINGLE)

enum {
  PROXIMITY,
  DOWN,
  MOTION,
  UP,
  N_SIGNALS
};

static guint signals[N_SIGNALS] = { 0, };

static gboolean
gtk_gesture_stylus_handle_event (GtkEventController *controller,
                                 const GdkEvent     *event)
{
  GdkModifierType modifiers;
  guint n_signal;
  gdouble x, y;

  GTK_EVENT_CONTROLLER_CLASS (gtk_gesture_stylus_parent_class)->handle_event (controller, event);

  if (!gdk_event_get_device_tool (event))
    return FALSE;
  if (!gdk_event_get_coords (event, &x, &y))
    return FALSE;

  switch ((guint) gdk_event_get_event_type (event))
    {
    case GDK_BUTTON_PRESS:
      n_signal = DOWN;
      break;
    case GDK_BUTTON_RELEASE:
      n_signal = UP;
      break;
    case GDK_MOTION_NOTIFY:
      gdk_event_get_state (event, &modifiers);

      if (modifiers & GDK_BUTTON1_MASK)
        n_signal = MOTION;
      else
        n_signal = PROXIMITY;
      break;
    default:
      return FALSE;
    }

  g_signal_emit (controller, signals[n_signal], 0, x, y);

  return TRUE;
}

static void
gtk_gesture_stylus_class_init (GtkGestureStylusClass *klass)
{
  GtkEventControllerClass *event_controller_class;

  event_controller_class = GTK_EVENT_CONTROLLER_CLASS (klass);
  event_controller_class->handle_event = gtk_gesture_stylus_handle_event;

  signals[PROXIMITY] =
    g_signal_new (I_("proximity"),
                  G_TYPE_FROM_CLASS (klass),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (GtkGestureStylusClass, proximity),
                  NULL, NULL, NULL,
                  G_TYPE_NONE, 2, G_TYPE_DOUBLE, G_TYPE_DOUBLE);
  signals[DOWN] =
    g_signal_new (I_("down"),
                  G_TYPE_FROM_CLASS (klass),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (GtkGestureStylusClass, down),
                  NULL, NULL, NULL,
                  G_TYPE_NONE, 2, G_TYPE_DOUBLE, G_TYPE_DOUBLE);
  signals[MOTION] =
    g_signal_new (I_("motion"),
                  G_TYPE_FROM_CLASS (klass),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (GtkGestureStylusClass, motion),
                  NULL, NULL, NULL,
                  G_TYPE_NONE, 2, G_TYPE_DOUBLE, G_TYPE_DOUBLE);
  signals[UP] =
    g_signal_new (I_("up"),
                  G_TYPE_FROM_CLASS (klass),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (GtkGestureStylusClass, up),
                  NULL, NULL, NULL,
                  G_TYPE_NONE, 2, G_TYPE_DOUBLE, G_TYPE_DOUBLE);
}

static void
gtk_gesture_stylus_init (GtkGestureStylus *gesture)
{
}

/**
 * gtk_gesture_stylus_new:
 *
 * Creates a new #GtkGestureStylus.
 *
 * Returns: a newly created stylus gesture
 *
 * Since: 3.94
 **/
GtkGesture *
gtk_gesture_stylus_new (void)
{
  return g_object_new (GTK_TYPE_GESTURE_STYLUS,
                       NULL);
}

static const GdkEvent *
gesture_get_current_event (GtkGestureStylus *gesture)
{
  GdkEventSequence *sequence;

  sequence = gtk_gesture_single_get_current_sequence (GTK_GESTURE_SINGLE (gesture));

  return gtk_gesture_get_last_event (GTK_GESTURE (gesture), sequence);
}

/**
 * gtk_gesture_stylus_get_axis:
 * @gesture: a #GtkGestureStylus
 * @axis: requested device axis
 * @value: (out): return location for the axis value
 *
 * Returns the current value for the requested @axis. This function
 * must be called from either the #GtkGestureStylus:down,
 * #GtkGestureStylus:motion, #GtkGestureStylus:up or #GtkGestureStylus:proximity
 * signals.
 *
 * Returns: #TRUE if there is a current value for the axis
 *
 * Since: 3.94
 **/
gboolean
gtk_gesture_stylus_get_axis (GtkGestureStylus *gesture,
			     GdkAxisUse        axis,
			     gdouble          *value)
{
  const GdkEvent *event;

  g_return_val_if_fail (GTK_IS_GESTURE_STYLUS (gesture), FALSE);
  g_return_val_if_fail (axis < GDK_AXIS_LAST, FALSE);
  g_return_val_if_fail (value != NULL, FALSE);

  event = gesture_get_current_event (gesture);
  if (!event)
    return FALSE;

  return gdk_event_get_axis (event, axis, value);
}

/**
 * gtk_gesture_stylus_get_axes:
 * @gesture: a GtkGestureStylus
 * @axes: array of requested axes, terminated with #GDK_AXIS_IGNORE
 * @values: (out): return location for the axis values
 *
 * Returns the current values for the requested @axes. This function
 * must be called from either the #GtkGestureStylus:down,
 * #GtkGestureStylus:motion, #GtkGestureStylus:up or #GtkGestureStylus:proximity
 * signals.
 *
 * Returns: #TRUE if there is a current value for the axes
 **/
gboolean
gtk_gesture_stylus_get_axes (GtkGestureStylus  *gesture,
			     GdkAxisUse         axes[],
			     gdouble          **values)
{
  const GdkEvent *event;
  GArray *array;
  gint i = 0;

  g_return_val_if_fail (GTK_IS_GESTURE_STYLUS (gesture), FALSE);
  g_return_val_if_fail (values != NULL, FALSE);

  event = gesture_get_current_event (gesture);
  if (!event)
    return FALSE;

  array = g_array_new (TRUE, FALSE, sizeof (gdouble));

  while (axes[i] != GDK_AXIS_IGNORE)
    {
      gdouble value;

      if (axes[i] >= GDK_AXIS_LAST)
        {
          g_warning ("Requesting unknown axis %d, did you "
                     "forget to add a last GDK_AXIS_IGNORE axis?",
                     axes[i]);
          g_array_free (array, TRUE);
          return FALSE;
        }

      gdk_event_get_axis (event, axes[i], &value);
      g_array_append_val (array, value);
      i++;
    }

  *values = (gdouble *) g_array_free (array, FALSE);
  return TRUE;
}

/**
 * gtk_gesture_stylus_get_backlog:
 * @gesture: a #GtkGestureStylus
 * @backlog: (out) (array length=n_elems): coordinates and times for the backlog events
 * @n_elems: (out): return location for the number of elements
 *
 * By default, GTK+ will limit rate of input events. On stylus input where
 * accuracy of strokes is paramount, this function returns the accumulated
 * coordinate/timing state before the emission of the current
 * #GtkGestureStylus:motion signal.
 *
 * This function may only be called within a #GtkGestureStylus::motion
 * signal handler, the state given in this signal and obtainable through
 * gtk_gesture_stylus_get_axis() call express the latest (most up-to-date)
 * state in motion history.
 *
 * @backlog is provided in chronological order.
 *
 * Returns: #TRUE if there is a backlog to unfold in the current state.
 **/
gboolean
gtk_gesture_stylus_get_backlog (GtkGestureStylus  *gesture,
				GdkTimeCoord     **backlog,
				guint             *n_elems)
{
  const GdkEvent *event;
  GArray *backlog_array;
  GList *history = NULL, *l;

  g_return_val_if_fail (GTK_IS_GESTURE_STYLUS (gesture), FALSE);
  g_return_val_if_fail (backlog != NULL && n_elems != NULL, FALSE);

  event = gesture_get_current_event (gesture);

  if (event)
    history = gdk_event_get_motion_history (event);
  if (!history)
    return FALSE;

  backlog_array = g_array_new (FALSE, FALSE, sizeof (GdkTimeCoord));
  for (l = history; l; l = l->next)
    {
      GdkTimeCoord *time_coord = l->data;

      g_array_append_val (backlog_array, *time_coord);
      time_coord = &g_array_index (backlog_array, GdkTimeCoord, backlog_array->len - 1);
      gtk_widget_translate_coordinatesf (gtk_get_event_widget (event),
                                         gtk_event_controller_get_widget (GTK_EVENT_CONTROLLER (gesture)),
                                         time_coord->axes[GDK_AXIS_X],
                                         time_coord->axes[GDK_AXIS_Y],
                                         &time_coord->axes[GDK_AXIS_X],
                                         &time_coord->axes[GDK_AXIS_Y]);
    }

  *n_elems = backlog_array->len;
  *backlog = (GdkTimeCoord *) g_array_free (backlog_array, FALSE);
  g_list_free (history);

  return TRUE;
}

/**
 * gtk_gesture_stylus_get_device_tool:
 * @gesture: a #GtkGestureStylus
 *
 * Returns the #GdkDeviceTool currently driving input through this gesture.
 * This function must be called from either the #GtkGestureStylus:down,
 * #GtkGestureStylus:motion, #GtkGestureStylus:up or #GtkGestureStylus:proximity
 * signals.
 *
 * Returns: (nullable) (transfer none): The current stylus tool
 **/
GdkDeviceTool *
gtk_gesture_stylus_get_device_tool (GtkGestureStylus *gesture)
{
  const GdkEvent *event;

  g_return_val_if_fail (GTK_IS_GESTURE_STYLUS (gesture), FALSE);

  event = gesture_get_current_event (gesture);
  if (!event)
    return NULL;

  return gdk_event_get_device_tool (event);
}