src/gtk/gtkvscrollbutton.c

   1 /* GTK - The GIMP Toolkit
   2  * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Library General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 3 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Library General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Library General Public
  15  * License along with this library. If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 /*
  19  * Modified by the GTK+ Team and others 1997-1999.  See the AUTHORS
  20  * file for a list of people on the GTK+ Team.  See the ChangeLog
  21  * files for a list of changes.  These files are distributed with
  22  * GTK+ at ftp://ftp.gtk.org/pub/gtk/.
  23  */
  24
  25  /*
  26   * Simple composite widget to provide vertical scrolling, based
  27   * on GtkRange widget code.
  28   * Modified by the Sylpheed Team and others 2003
  29   */
  30
  31 #ifdef HAVE_CONFIG_H
  32 #  include "config.h"
  33 #endif
  34
  35 #include <glib.h>
  36 #include <gtk/gtksignal.h>
  37 #include <gtk/gtkbutton.h>
  38 #include <gtk/gtkmisc.h>
  39 #include <gtk/gtk.h>
  40 #include <gtk/gtkbox.h>
  41 #include <gtk/gtkmain.h>
  42
  43 #include "gtkvscrollbutton.h"
  44
  45 #define SCROLL_TIMER_LENGTH  20
  46 #define SCROLL_INITIAL_DELAY 100        /* must hold button this long before ... */
  47 #define SCROLL_LATER_DELAY   20 /* ... it starts repeating at this rate  */
  48 #define SCROLL_DELAY_LENGTH  300
  49
  50
  51 enum {
  52     ARG_0,
  53     ARG_ADJUSTMENT
  54 };
  55
  56 static void gtk_vscrollbutton_class_init(GtkVScrollbuttonClass * klass);
  57 static void gtk_vscrollbutton_init(GtkVScrollbutton * vscrollbutton);
  58
  59 GtkType gtk_vscrollbutton_get_type              (void);
  60 GtkWidget *gtk_vscrollbutton_new                (GtkAdjustment    *adjustment);
  61
  62 static gint gtk_vscrollbutton_button_release    (GtkWidget        *widget,
  63                                                  GdkEventButton   *event,
  64                                                  GtkVScrollbutton *scrollbutton);
  65
  66 static void gtk_vscrollbutton_set_adjustment    (GtkVScrollbutton *scrollbutton,
  67                                                  GtkAdjustment    *adjustment);
  68
  69 static gint gtk_vscrollbutton_button_press      (GtkWidget        *widget,
  70                                                  GdkEventButton   *event,
  71                                                  GtkVScrollbutton *scrollbutton);
  72
  73 static gint gtk_vscrollbutton_button_release    (GtkWidget        *widget,
  74                                                  GdkEventButton   *event,
  75                                                  GtkVScrollbutton *scrollbutton);
  76
  77 gint gtk_vscrollbutton_scroll           (GtkVScrollbutton *scrollbutton);
  78
  79 static gboolean gtk_vscrollbutton_timer_1st_time(GtkVScrollbutton *scrollbutton);
  80
  81 static void gtk_vscrollbutton_add_timer         (GtkVScrollbutton *scrollbutton);
  82
  83 static void gtk_vscrollbutton_remove_timer      (GtkVScrollbutton *scrollbutton);
  84
  85 static gint gtk_real_vscrollbutton_timer        (GtkVScrollbutton *scrollbutton);
  86
  87 static void gtk_vscrollbutton_set_sensitivity   (GtkAdjustment    *adjustment,
  88                                                  GtkVScrollbutton *scrollbutton);
  89
  90 GtkType gtk_vscrollbutton_get_type(void)
  91 {
  92     static GtkType vscrollbutton_type = 0;
  93
  94     if (!vscrollbutton_type) {
  95         static const GtkTypeInfo vscrollbutton_info = {
  96             "GtkVScrollbutton",
  97             sizeof(GtkVScrollbutton),
  98             sizeof(GtkVScrollbuttonClass),
  99             (GtkClassInitFunc) gtk_vscrollbutton_class_init,
 100             (GtkObjectInitFunc) gtk_vscrollbutton_init,
 101             /* reserved_1 */ NULL,
 102             /* reserved_2 */ NULL,
 103             (GtkClassInitFunc) NULL,
 104         };
 105
 106         vscrollbutton_type =
 107             gtk_type_unique(GTK_TYPE_VBOX, &vscrollbutton_info);
 108     }
 109
 110     return vscrollbutton_type;
 111 }
 112
 113 static void gtk_vscrollbutton_class_init(GtkVScrollbuttonClass *class)
 114 {
 115 }
 116
 117 static void gtk_vscrollbutton_init(GtkVScrollbutton *scrollbutton)
 118 {
 119     GtkWidget *arrow;
 120     scrollbutton->upbutton = gtk_button_new();
 121     scrollbutton->downbutton = gtk_button_new();
 122     arrow = gtk_arrow_new(GTK_ARROW_UP, GTK_SHADOW_NONE);
 123     gtk_widget_show(arrow);
 124     gtk_container_add(GTK_CONTAINER(scrollbutton->upbutton), arrow);
 125     gtk_widget_set_size_request(scrollbutton->upbutton, -1, 16);
 126     arrow = gtk_arrow_new(GTK_ARROW_DOWN, GTK_SHADOW_NONE);
 127     gtk_widget_show(arrow);
 128     gtk_container_add(GTK_CONTAINER(scrollbutton->downbutton), arrow);
 129     gtk_widget_set_size_request(scrollbutton->downbutton, -1, 16);
 130     GTK_WIDGET_UNSET_FLAGS(scrollbutton->upbutton, GTK_CAN_FOCUS);
 131     GTK_WIDGET_UNSET_FLAGS(scrollbutton->downbutton, GTK_CAN_FOCUS);
 132     gtk_widget_show(scrollbutton->downbutton);
 133     gtk_widget_show(scrollbutton->upbutton);
 134
 135     g_signal_connect(G_OBJECT(scrollbutton->upbutton),
 136                        "button_press_event",
 137                        G_CALLBACK(gtk_vscrollbutton_button_press),
 138                        scrollbutton);
 139     g_signal_connect(G_OBJECT(scrollbutton->downbutton),
 140                        "button_press_event",
 141                        G_CALLBACK(gtk_vscrollbutton_button_press),
 142                        scrollbutton);
 143     g_signal_connect(G_OBJECT(scrollbutton->upbutton),
 144                      "button_release_event",
 145                      G_CALLBACK
 146                      (gtk_vscrollbutton_button_release), scrollbutton);
 147     g_signal_connect(G_OBJECT(scrollbutton->downbutton),
 148                      "button_release_event",
 149                      G_CALLBACK
 150                      (gtk_vscrollbutton_button_release), scrollbutton);
 151     gtk_box_pack_start(GTK_BOX(&scrollbutton->vbox),
 152                        scrollbutton->upbutton, TRUE, TRUE, 0);
 153     gtk_box_pack_end(GTK_BOX(&scrollbutton->vbox),
 154                      scrollbutton->downbutton, TRUE, TRUE, 0);
 155     scrollbutton->timer = 0;
 156 }
 157
 158 GtkWidget *gtk_vscrollbutton_new(GtkAdjustment *adjustment)
 159 {
 160     GtkWidget *vscrollbutton;
 161     vscrollbutton = GTK_WIDGET(gtk_type_new(gtk_vscrollbutton_get_type()));
 162     gtk_vscrollbutton_set_adjustment(GTK_VSCROLLBUTTON(vscrollbutton),
 163                                      adjustment);
 164     g_signal_connect(G_OBJECT(GTK_VSCROLLBUTTON(vscrollbutton)->adjustment),
 165                        "value_changed",
 166                        G_CALLBACK
 167                        (gtk_vscrollbutton_set_sensitivity), vscrollbutton);
 168     g_signal_connect(G_OBJECT(GTK_VSCROLLBUTTON(vscrollbutton)->adjustment),
 169                        "changed",
 170                        G_CALLBACK
 171                        (gtk_vscrollbutton_set_sensitivity), vscrollbutton);
 172     return vscrollbutton;
 173 }
 174
 175
 176 void gtk_vscrollbutton_set_adjustment(GtkVScrollbutton *scrollbutton,
 177                                       GtkAdjustment *adjustment)
 178 {
 179     g_return_if_fail(scrollbutton != NULL);
 180     g_return_if_fail(GTK_IS_VSCROLLBUTTON(scrollbutton));
 181
 182     if (!adjustment)
 183             adjustment =
 184             GTK_ADJUSTMENT(gtk_adjustment_new(0.0, 0.0, 0.0, 0.0, 0.0, 0.0));
 185     else
 186         g_return_if_fail(GTK_IS_ADJUSTMENT(adjustment));
 187
 188     if (scrollbutton->adjustment != adjustment) {
 189         if (scrollbutton->adjustment) {
 190             g_signal_handlers_disconnect_matched(scrollbutton->adjustment,
 191                                                  G_SIGNAL_MATCH_DATA,
 192                                                  0, 0, NULL, NULL,
 193                                                  (gpointer) scrollbutton);
 194             g_object_unref(G_OBJECT(scrollbutton->adjustment));
 195         }
 196
 197         scrollbutton->adjustment = adjustment;
 198         g_object_ref(G_OBJECT(adjustment));
 199         gtk_object_sink(GTK_OBJECT(adjustment));
 200     }
 201 }
 202
 203 static gint gtk_vscrollbutton_button_press(GtkWidget *widget,
 204                                            GdkEventButton *event,
 205                                            GtkVScrollbutton *scrollbutton)
 206 {
 207     if (!GTK_WIDGET_HAS_FOCUS(widget))
 208         gtk_widget_grab_focus(widget);
 209
 210     if (scrollbutton->button == 0) {
 211         gtk_grab_add(widget);
 212         scrollbutton->button = event->button;
 213
 214         if (widget == scrollbutton->downbutton)
 215             scrollbutton->scroll_type = GTK_SCROLL_STEP_FORWARD;
 216         else
 217             scrollbutton->scroll_type = GTK_SCROLL_STEP_BACKWARD;
 218         gtk_vscrollbutton_scroll(scrollbutton);
 219         gtk_vscrollbutton_add_timer(scrollbutton);
 220     }
 221     return TRUE;
 222 }
 223
 224
 225 static gint gtk_vscrollbutton_button_release(GtkWidget *widget,
 226                                              GdkEventButton *event,
 227                                              GtkVScrollbutton *scrollbutton)
 228 {
 229     if (!GTK_WIDGET_HAS_FOCUS(widget))
 230         gtk_widget_grab_focus(widget);
 231
 232     if (scrollbutton->button == event->button) {
 233         gtk_grab_remove(widget);
 234
 235         scrollbutton->button = 0;
 236         gtk_vscrollbutton_remove_timer(scrollbutton);
 237         gtk_vscrollbutton_set_sensitivity(scrollbutton->adjustment, scrollbutton);
 238     }
 239     return TRUE;
 240 }
 241
 242 gint gtk_vscrollbutton_scroll(GtkVScrollbutton *scrollbutton)
 243 {
 244     gfloat new_value;
 245     gint return_val;
 246
 247     g_return_val_if_fail(scrollbutton != NULL, FALSE);
 248     g_return_val_if_fail(GTK_IS_VSCROLLBUTTON(scrollbutton), FALSE);
 249
 250     new_value = scrollbutton->adjustment->value;
 251     return_val = TRUE;
 252
 253     switch (scrollbutton->scroll_type) {
 254
 255     case GTK_SCROLL_STEP_BACKWARD:
 256         new_value -= scrollbutton->adjustment->step_increment;
 257         if (new_value <= scrollbutton->adjustment->lower) {
 258             new_value = scrollbutton->adjustment->lower;
 259             return_val = FALSE;
 260             scrollbutton->timer = 0;
 261         }
 262         break;
 263
 264     case GTK_SCROLL_STEP_FORWARD:
 265         new_value += scrollbutton->adjustment->step_increment;
 266         if (new_value >=
 267             (scrollbutton->adjustment->upper -
 268              scrollbutton->adjustment->page_size)) {
 269             new_value =
 270                 scrollbutton->adjustment->upper -
 271                 scrollbutton->adjustment->page_size;
 272             return_val = FALSE;
 273             scrollbutton->timer = 0;
 274         }
 275         break;
 276
 277     default:
 278         break;
 279
 280     }
 281
 282     if (new_value != scrollbutton->adjustment->value) {
 283         scrollbutton->adjustment->value = new_value;
 284         g_signal_emit_by_name(G_OBJECT
 285                                 (scrollbutton->adjustment),
 286                                 "value_changed");
 287         gtk_widget_queue_resize(GTK_WIDGET(scrollbutton)); /* ensure resize */
 288     }
 289
 290     return return_val;
 291 }
 292
 293 static gboolean
 294 gtk_vscrollbutton_timer_1st_time(GtkVScrollbutton *scrollbutton)
 295 {
 296     /*
 297      * If the real timeout function succeeds and the timeout is still set,
 298      * replace it with a quicker one so successive scrolling goes faster.
 299      */
 300     g_object_ref(G_OBJECT(scrollbutton));
 301     if (scrollbutton->timer) {
 302         /* We explicitely remove ourselves here in the paranoia
 303          * that due to things happening above in the callback
 304          * above, we might have been removed, and another added.
 305          */
 306         g_source_remove(scrollbutton->timer);
 307         scrollbutton->timer = g_timeout_add(SCROLL_LATER_DELAY,
 308                                             (GtkFunction)
 309                                             gtk_real_vscrollbutton_timer,
 310                                             scrollbutton);
 311     }
 312     g_object_unref(G_OBJECT(scrollbutton));
 313     return FALSE;               /* don't keep calling this function */
 314 }
 315
 316
 317 static void gtk_vscrollbutton_add_timer(GtkVScrollbutton *scrollbutton)
 318 {
 319     g_return_if_fail(scrollbutton != NULL);
 320     g_return_if_fail(GTK_IS_VSCROLLBUTTON(scrollbutton));
 321
 322     if (!scrollbutton->timer) {
 323         scrollbutton->need_timer = TRUE;
 324         scrollbutton->timer = g_timeout_add(SCROLL_INITIAL_DELAY,
 325                                             (GtkFunction)
 326                                             gtk_vscrollbutton_timer_1st_time,
 327                                             scrollbutton);
 328     }
 329 }
 330
 331 static void gtk_vscrollbutton_remove_timer(GtkVScrollbutton *scrollbutton)
 332 {
 333     g_return_if_fail(scrollbutton != NULL);
 334     g_return_if_fail(GTK_IS_VSCROLLBUTTON(scrollbutton));
 335
 336     if (scrollbutton->timer) {
 337         g_source_remove(scrollbutton->timer);
 338         scrollbutton->timer = 0;
 339     }
 340     scrollbutton->need_timer = FALSE;
 341 }
 342
 343 static gint gtk_real_vscrollbutton_timer(GtkVScrollbutton *scrollbutton)
 344 {
 345     gint return_val;
 346
 347     GDK_THREADS_ENTER();
 348
 349     return_val = TRUE;
 350     if (!scrollbutton->timer) {
 351         return_val = FALSE;
 352         if (scrollbutton->need_timer)
 353             scrollbutton->timer =
 354                 g_timeout_add(SCROLL_TIMER_LENGTH,
 355                               (GtkFunction) gtk_real_vscrollbutton_timer,
 356                               (gpointer) scrollbutton);
 357         else {
 358             GDK_THREADS_LEAVE();
 359             return FALSE;
 360         }
 361         scrollbutton->need_timer = FALSE;
 362     }
 363     GDK_THREADS_LEAVE();
 364     return_val = gtk_vscrollbutton_scroll(scrollbutton);
 365     return return_val;
 366 }
 367
 368 static void gtk_vscrollbutton_set_sensitivity   (GtkAdjustment    *adjustment,
 369                                                  GtkVScrollbutton *scrollbutton)
 370 {
 371         if (!GTK_WIDGET_REALIZED(GTK_WIDGET(scrollbutton))) return;
 372         if (scrollbutton->button != 0) return; /* not while something is pressed */
 373
 374         gtk_widget_set_sensitive(scrollbutton->upbutton,
 375                                  (adjustment->value > adjustment->lower));
 376         gtk_widget_set_sensitive(scrollbutton->downbutton,
 377                                  (adjustment->value <  (adjustment->upper - adjustment->page_size)));
 378 }