src/ctl_keyboard.cpp

   1 /* Calf DSP Library
   2  * Barely started keyboard widget. Planned to be usable as
   3  * a ruler for curves, and possibly as input widget in future
   4  * as well (that's what event sink interface is for, at least).
   5  *
   6  * Copyright (C) 2008 Krzysztof Foltman
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2 of the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General
  19  * Public License along with this program; if not, write to the
  20  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  21  * Boston, MA 02111-1307, USA.
  22  */
  23 #include <calf/ctl_keyboard.h>
  24 #include <stdint.h>
  25 #include <malloc.h>
  26
  27 static const int semitones_b[] = { 1, 3, -1, 6, 8, 10, -1 };
  28 static const int semitones_w[] = { 0, 2, 4, 5, 7, 9, 11 };
  29
  30
  31 GtkWidget *
  32 calf_keyboard_new()
  33 {
  34     GtkWidget *widget = GTK_WIDGET( g_object_new (CALF_TYPE_KEYBOARD, NULL ));
  35     return widget;
  36 }
  37
  38 static gboolean
  39 calf_keyboard_expose (GtkWidget *widget, GdkEventExpose *event)
  40 {
  41     g_assert(CALF_IS_KEYBOARD(widget));
  42
  43     GdkColor scWhiteKey = { 0, 65535, 65535, 65535 };
  44     GdkColor scBlackKey = { 0, 0, 0, 0 };
  45     GdkColor scOutline = { 0, 0, 0, 0 };
  46     CalfKeyboard *self = CALF_KEYBOARD(widget);
  47     GdkWindow *window = widget->window;
  48     cairo_t *c = gdk_cairo_create(GDK_DRAWABLE(window));
  49     int sy = widget->allocation.height - 1;
  50     cairo_set_line_join(c, CAIRO_LINE_JOIN_MITER);
  51     cairo_set_line_width(c, 1);
  52
  53     for (int i = 0; i < self->nkeys; i++)
  54     {
  55         CalfKeyboard::KeyInfo ki = { 0.5 + 12 * i, 0.5, 12, sy, 12 * (i / 7) + semitones_w[i % 7], false };
  56         cairo_new_path(c);
  57         gdk_cairo_set_source_color(c, &scWhiteKey);
  58         if (!self->sink->pre_draw(c, ki))
  59         {
  60             cairo_rectangle(c, ki.x, ki.y, ki.width, ki.height);
  61             cairo_fill_preserve(c);
  62             gdk_cairo_set_source_color(c, &scOutline);
  63             if (!self->sink->pre_draw_outline(c, ki))
  64                 cairo_stroke(c);
  65             else
  66                 cairo_new_path(c);
  67             self->sink->post_draw(c, ki);
  68         }
  69     }
  70
  71     for (int i = 0; i < self->nkeys - 1; i++)
  72     {
  73         if ((1 << (i % 7)) & 59)
  74         {
  75             CalfKeyboard::KeyInfo ki = { 8.5 + 12 * i, 0.5, 8, sy * 3 / 5, 12 * (i / 7) + semitones_b[i % 7], true };
  76             cairo_new_path(c);
  77             cairo_rectangle(c, ki.x, ki.y, ki.width, ki.height);
  78             gdk_cairo_set_source_color(c, &scBlackKey);
  79             if (!self->sink->pre_draw(c, ki))
  80             {
  81                 cairo_fill(c);
  82                 self->sink->post_draw(c, ki);
  83             }
  84         }
  85     }
  86
  87     self->sink->post_all(c);
  88
  89     cairo_destroy(c);
  90
  91     return TRUE;
  92 }
  93
  94 static void
  95 calf_keyboard_realize(GtkWidget *widget)
  96 {
  97     GTK_WIDGET_SET_FLAGS(widget, GTK_REALIZED);
  98
  99     GdkWindowAttr attributes;
 100     attributes.event_mask = GDK_EXPOSURE_MASK | GDK_BUTTON1_MOTION_MASK |
 101         GDK_KEY_PRESS_MASK | GDK_KEY_RELEASE_MASK |
 102         GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK;
 103     attributes.x = widget->allocation.x;
 104     attributes.y = widget->allocation.y;
 105     attributes.width = widget->allocation.width;
 106     attributes.height = widget->allocation.height;
 107     attributes.wclass = GDK_INPUT_OUTPUT;
 108     attributes.window_type = GDK_WINDOW_CHILD;
 109
 110     widget->window = gdk_window_new(gtk_widget_get_parent_window (widget), &attributes, GDK_WA_X | GDK_WA_Y);
 111
 112     gdk_window_set_user_data(widget->window, widget);
 113     widget->style = gtk_style_attach(widget->style, widget->window);
 114 }
 115
 116 static void
 117 calf_keyboard_size_request (GtkWidget *widget,
 118                            GtkRequisition *requisition)
 119 {
 120     CalfKeyboard *self = CALF_KEYBOARD(widget);
 121     g_assert(CALF_IS_KEYBOARD(widget));
 122
 123     requisition->width = 12 * self->nkeys + 1;
 124     requisition->height = 32;
 125 }
 126
 127 static void
 128 calf_keyboard_size_allocate (GtkWidget *widget,
 129                            GtkAllocation *allocation)
 130 {
 131     // CalfKeyboard *self = CALF_KEYBOARD(widget);
 132     g_assert(CALF_IS_KEYBOARD(widget));
 133     widget->allocation = *allocation;
 134     widget->allocation.width = widget->requisition.width;
 135
 136     if (GTK_WIDGET_REALIZED(widget))
 137         gdk_window_move_resize(widget->window,
 138             allocation->x + (allocation->width - widget->allocation.width) / 2, allocation->y,
 139             widget->allocation.width, allocation->height );
 140 }
 141
 142 static gboolean
 143 calf_keyboard_key_press (GtkWidget *widget, GdkEventKey *event)
 144 {
 145     g_assert(CALF_IS_KEYBOARD(widget));
 146     CalfKeyboard *self = CALF_KEYBOARD(widget);
 147     if (!self->sink)
 148         return FALSE;
 149     return FALSE;
 150 }
 151
 152 int
 153 calf_keyboard_pos_to_note (CalfKeyboard *kb, int x, int y, int *vel = NULL)
 154 {
 155     // first try black keys
 156     if (y <= kb->parent.allocation.height * 3 / 5 && x >= 0 && (x - 8) % 12 < 8)
 157     {
 158         int blackkey = (x - 8) / 12;
 159         if (blackkey < kb->nkeys && (59 & (1 << (blackkey % 7))))
 160         {
 161             return semitones_b[blackkey % 7] + 12 * (blackkey / 7);
 162         }
 163     }
 164     // if not a black key, then which white one?
 165     int whitekey = x / 12;
 166     // semitones within octave + 12 semitones per octave
 167     return semitones_w[whitekey % 7] + 12 * (whitekey / 7);
 168 }
 169
 170 static gboolean
 171 calf_keyboard_button_press (GtkWidget *widget, GdkEventButton *event)
 172 {
 173     g_assert(CALF_IS_KEYBOARD(widget));
 174     CalfKeyboard *self = CALF_KEYBOARD(widget);
 175     if (!self->interactive)
 176         return FALSE;
 177     gtk_widget_grab_focus(widget);
 178     int vel = 127;
 179     self->last_key = calf_keyboard_pos_to_note(self, (int)event->x, (int)event->y, &vel);
 180     if (self->last_key != -1)
 181         self->sink->note_on(self->last_key, vel);
 182     return FALSE;
 183 }
 184
 185 static gboolean
 186 calf_keyboard_button_release (GtkWidget *widget, GdkEventButton *event)
 187 {
 188     g_assert(CALF_IS_KEYBOARD(widget));
 189     CalfKeyboard *self = CALF_KEYBOARD(widget);
 190     if (!self->interactive)
 191         return FALSE;
 192     if (self->last_key != -1)
 193         self->sink->note_off(self->last_key);
 194     return FALSE;
 195 }
 196
 197 static gboolean
 198 calf_keyboard_pointer_motion (GtkWidget *widget, GdkEventMotion *event)
 199 {
 200     g_assert(CALF_IS_KEYBOARD(widget));
 201     CalfKeyboard *self = CALF_KEYBOARD(widget);
 202     if (!self->interactive)
 203         return FALSE;
 204     int vel = 127;
 205     int key = calf_keyboard_pos_to_note(self, (int)event->x, (int)event->y, &vel);
 206     if (key != self->last_key)
 207     {
 208         if (self->last_key != -1)
 209             self->sink->note_off(self->last_key);
 210         self->last_key = key;
 211         if (self->last_key != -1)
 212             self->sink->note_on(self->last_key, vel);
 213     }
 214     return FALSE;
 215 }
 216
 217 static void
 218 calf_keyboard_class_init (CalfKeyboardClass *klass)
 219 {
 220     GtkWidgetClass *widget_class = GTK_WIDGET_CLASS(klass);
 221     widget_class->realize = calf_keyboard_realize;
 222     widget_class->size_allocate = calf_keyboard_size_allocate;
 223     widget_class->expose_event = calf_keyboard_expose;
 224     widget_class->size_request = calf_keyboard_size_request;
 225     widget_class->button_press_event = calf_keyboard_button_press;
 226     widget_class->button_release_event = calf_keyboard_button_release;
 227     widget_class->motion_notify_event = calf_keyboard_pointer_motion;
 228     widget_class->key_press_event = calf_keyboard_key_press;
 229     // widget_class->scroll_event = calf_keyboard_scroll;
 230 }
 231
 232 static void
 233 calf_keyboard_init (CalfKeyboard *self)
 234 {
 235     static CalfKeyboard::EventAdapter default_sink;
 236     GtkWidget *widget = GTK_WIDGET(self);
 237     g_assert(CALF_IS_KEYBOARD(widget));
 238     GTK_WIDGET_SET_FLAGS (GTK_WIDGET(self), GTK_CAN_FOCUS);
 239     self->nkeys = 7 * 3 + 1;
 240     self->sink = &default_sink;
 241     self->last_key = -1;
 242 }
 243
 244 GType
 245 calf_keyboard_get_type (void)
 246 {
 247     static GType type = 0;
 248     if (!type) {
 249
 250         static const GTypeInfo type_info = {
 251             sizeof(CalfKeyboardClass),
 252             NULL, /* base_init */
 253             NULL, /* base_finalize */
 254             (GClassInitFunc)calf_keyboard_class_init,
 255             NULL, /* class_finalize */
 256             NULL, /* class_data */
 257             sizeof(CalfKeyboard),
 258             0,    /* n_preallocs */
 259             (GInstanceInitFunc)calf_keyboard_init
 260         };
 261
 262         for (int i = 0; ; i++) {
 263             char *name = g_strdup_printf("CalfKeyboard%u%d",
 264                 ((unsigned int)(intptr_t)calf_keyboard_class_init) >> 16, i);
 265             if (g_type_from_name(name)) {
 266                 free(name);
 267                 continue;
 268             }
 269             type = g_type_register_static(GTK_TYPE_WIDGET,
 270                                           name,
 271                                           &type_info,
 272                                           (GTypeFlags)0);
 273             free(name);
 274             break;
 275         }
 276     }
 277     return type;
 278 }
 279