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 #ifndef MAEMO
 126     gtk_widget_set_size_request(scrollbutton->upbutton, -1, 16);
 127 #else
 128     gtk_widget_set_size_request(scrollbutton->upbutton, -1, arrow->requisition.height + 8);
 129 #endif
 130     arrow = gtk_arrow_new(GTK_ARROW_DOWN, GTK_SHADOW_NONE);
 131     gtk_widget_show(arrow);
 132     gtk_container_add(GTK_CONTAINER(scrollbutton->downbutton), arrow);
 133 #ifndef MAEMO
 134     gtk_widget_set_size_request(scrollbutton->downbutton, -1, 16);
 135 #else
 136     gtk_widget_set_size_request(scrollbutton->downbutton, -1, arrow->requisition.height + 8);
 137 #endif
 138     GTK_WIDGET_UNSET_FLAGS(scrollbutton->upbutton, GTK_CAN_FOCUS);
 139     GTK_WIDGET_UNSET_FLAGS(scrollbutton->downbutton, GTK_CAN_FOCUS);
 140     gtk_widget_show(scrollbutton->downbutton);
 141     gtk_widget_show(scrollbutton->upbutton);
 142
 143     g_signal_connect(G_OBJECT(scrollbutton->upbutton),
 144                        "button_press_event",
 145                        G_CALLBACK(gtk_vscrollbutton_button_press),
 146                        scrollbutton);
 147     g_signal_connect(G_OBJECT(scrollbutton->downbutton),
 148                        "button_press_event",
 149                        G_CALLBACK(gtk_vscrollbutton_button_press),
 150                        scrollbutton);
 151     g_signal_connect(G_OBJECT(scrollbutton->upbutton),
 152                      "button_release_event",
 153                      G_CALLBACK
 154                      (gtk_vscrollbutton_button_release), scrollbutton);
 155     g_signal_connect(G_OBJECT(scrollbutton->downbutton),
 156                      "button_release_event",
 157                      G_CALLBACK
 158                      (gtk_vscrollbutton_button_release), scrollbutton);
 159     gtk_box_pack_start(GTK_BOX(&scrollbutton->vbox),
 160                        scrollbutton->upbutton, TRUE, TRUE, 0);
 161     gtk_box_pack_end(GTK_BOX(&scrollbutton->vbox),
 162                      scrollbutton->downbutton, TRUE, TRUE, 0);
 163     scrollbutton->timer = 0;
 164 }
 165
 166 GtkWidget *gtk_vscrollbutton_new(GtkAdjustment *adjustment)
 167 {
 168     GtkWidget *vscrollbutton;
 169     vscrollbutton = GTK_WIDGET(gtk_type_new(gtk_vscrollbutton_get_type()));
 170     gtk_vscrollbutton_set_adjustment(GTK_VSCROLLBUTTON(vscrollbutton),
 171                                      adjustment);
 172     g_signal_connect(G_OBJECT(GTK_VSCROLLBUTTON(vscrollbutton)->adjustment),
 173                        "value_changed",
 174                        G_CALLBACK
 175                        (gtk_vscrollbutton_set_sensitivity), vscrollbutton);
 176     g_signal_connect(G_OBJECT(GTK_VSCROLLBUTTON(vscrollbutton)->adjustment),
 177                        "changed",
 178                        G_CALLBACK
 179                        (gtk_vscrollbutton_set_sensitivity), vscrollbutton);
 180     return vscrollbutton;
 181 }
 182
 183
 184 void gtk_vscrollbutton_set_adjustment(GtkVScrollbutton *scrollbutton,
 185                                       GtkAdjustment *adjustment)
 186 {
 187     g_return_if_fail(scrollbutton != NULL);
 188     g_return_if_fail(GTK_IS_VSCROLLBUTTON(scrollbutton));
 189
 190     if (!adjustment)
 191             adjustment =
 192             GTK_ADJUSTMENT(gtk_adjustment_new(0.0, 0.0, 0.0, 0.0, 0.0, 0.0));
 193     else
 194         g_return_if_fail(GTK_IS_ADJUSTMENT(adjustment));
 195
 196     if (scrollbutton->adjustment != adjustment) {
 197         if (scrollbutton->adjustment) {
 198             g_signal_handlers_disconnect_matched(scrollbutton->adjustment,
 199                                                  G_SIGNAL_MATCH_DATA,
 200                                                  0, 0, NULL, NULL,
 201                                                  (gpointer) scrollbutton);
 202             g_object_unref(G_OBJECT(scrollbutton->adjustment));
 203         }
 204
 205         scrollbutton->adjustment = adjustment;
 206         g_object_ref(G_OBJECT(adjustment));
 207         gtk_object_sink(GTK_OBJECT(adjustment));
 208     }
 209 }
 210
 211 static gint gtk_vscrollbutton_button_press(GtkWidget *widget,
 212                                            GdkEventButton *event,
 213                                            GtkVScrollbutton *scrollbutton)
 214 {
 215     if (!GTK_WIDGET_HAS_FOCUS(widget))
 216         gtk_widget_grab_focus(widget);
 217
 218     if (scrollbutton->button == 0) {
 219         gtk_grab_add(widget);
 220         scrollbutton->button = event->button;
 221
 222         if (widget == scrollbutton->downbutton)
 223             scrollbutton->scroll_type = GTK_SCROLL_STEP_FORWARD;
 224         else
 225             scrollbutton->scroll_type = GTK_SCROLL_STEP_BACKWARD;
 226         gtk_vscrollbutton_scroll(scrollbutton);
 227         gtk_vscrollbutton_add_timer(scrollbutton);
 228     }
 229     return TRUE;
 230 }
 231
 232
 233 static gint gtk_vscrollbutton_button_release(GtkWidget *widget,
 234                                              GdkEventButton *event,
 235                                              GtkVScrollbutton *scrollbutton)
 236 {
 237     if (!GTK_WIDGET_HAS_FOCUS(widget))
 238         gtk_widget_grab_focus(widget);
 239
 240     if (scrollbutton->button == event->button) {
 241         gtk_grab_remove(widget);
 242
 243         scrollbutton->button = 0;
 244         gtk_vscrollbutton_remove_timer(scrollbutton);
 245         gtk_vscrollbutton_set_sensitivity(scrollbutton->adjustment, scrollbutton);
 246     }
 247     return TRUE;
 248 }
 249
 250 gint gtk_vscrollbutton_scroll(GtkVScrollbutton *scrollbutton)
 251 {
 252     gfloat new_value;
 253     gint return_val;
 254
 255     g_return_val_if_fail(scrollbutton != NULL, FALSE);
 256     g_return_val_if_fail(GTK_IS_VSCROLLBUTTON(scrollbutton), FALSE);
 257
 258     new_value = scrollbutton->adjustment->value;
 259     return_val = TRUE;
 260
 261     switch (scrollbutton->scroll_type) {
 262
 263     case GTK_SCROLL_STEP_BACKWARD:
 264         new_value -= scrollbutton->adjustment->step_increment;
 265         if (new_value <= scrollbutton->adjustment->lower) {
 266             new_value = scrollbutton->adjustment->lower;
 267             return_val = FALSE;
 268             scrollbutton->timer = 0;
 269         }
 270         break;
 271
 272     case GTK_SCROLL_STEP_FORWARD:
 273         new_value += scrollbutton->adjustment->step_increment;
 274         if (new_value >=
 275             (scrollbutton->adjustment->upper -
 276              scrollbutton->adjustment->page_size)) {
 277             new_value =
 278                 scrollbutton->adjustment->upper -
 279                 scrollbutton->adjustment->page_size;
 280             return_val = FALSE;
 281             scrollbutton->timer = 0;
 282         }
 283         break;
 284
 285     default:
 286         break;
 287
 288     }
 289
 290     if (new_value != scrollbutton->adjustment->value) {
 291         scrollbutton->adjustment->value = new_value;
 292         g_signal_emit_by_name(G_OBJECT
 293                                 (scrollbutton->adjustment),
 294                                 "value_changed");
 295         gtk_widget_queue_resize(GTK_WIDGET(scrollbutton)); /* ensure resize */
 296     }
 297
 298     return return_val;
 299 }
 300
 301 static gboolean
 302 gtk_vscrollbutton_timer_1st_time(GtkVScrollbutton *scrollbutton)
 303 {
 304     /*
 305      * If the real timeout function succeeds and the timeout is still set,
 306      * replace it with a quicker one so successive scrolling goes faster.
 307      */
 308     g_object_ref(G_OBJECT(scrollbutton));
 309     if (scrollbutton->timer) {
 310         /* We explicitely remove ourselves here in the paranoia
 311          * that due to things happening above in the callback
 312          * above, we might have been removed, and another added.
 313          */
 314         g_source_remove(scrollbutton->timer);
 315         scrollbutton->timer = g_timeout_add(SCROLL_LATER_DELAY,
 316                                             (GtkFunction)
 317                                             gtk_real_vscrollbutton_timer,
 318                                             scrollbutton);
 319     }
 320     g_object_unref(G_OBJECT(scrollbutton));
 321     return FALSE;               /* don't keep calling this function */
 322 }
 323
 324
 325 static void gtk_vscrollbutton_add_timer(GtkVScrollbutton *scrollbutton)
 326 {
 327     g_return_if_fail(scrollbutton != NULL);
 328     g_return_if_fail(GTK_IS_VSCROLLBUTTON(scrollbutton));
 329
 330     if (!scrollbutton->timer) {
 331         scrollbutton->need_timer = TRUE;
 332         scrollbutton->timer = g_timeout_add(SCROLL_INITIAL_DELAY,
 333                                             (GtkFunction)
 334                                             gtk_vscrollbutton_timer_1st_time,
 335                                             scrollbutton);
 336     }
 337 }
 338
 339 static void gtk_vscrollbutton_remove_timer(GtkVScrollbutton *scrollbutton)
 340 {
 341     g_return_if_fail(scrollbutton != NULL);
 342     g_return_if_fail(GTK_IS_VSCROLLBUTTON(scrollbutton));
 343
 344     if (scrollbutton->timer) {
 345         g_source_remove(scrollbutton->timer);
 346         scrollbutton->timer = 0;
 347     }
 348     scrollbutton->need_timer = FALSE;
 349 }
 350
 351 static gint gtk_real_vscrollbutton_timer(GtkVScrollbutton *scrollbutton)
 352 {
 353     gint return_val;
 354
 355     GDK_THREADS_ENTER();
 356
 357     return_val = TRUE;
 358     if (!scrollbutton->timer) {
 359         return_val = FALSE;
 360         if (scrollbutton->need_timer)
 361             scrollbutton->timer =
 362                 g_timeout_add(SCROLL_TIMER_LENGTH,
 363                               (GtkFunction) gtk_real_vscrollbutton_timer,
 364                               (gpointer) scrollbutton);
 365         else {
 366             GDK_THREADS_LEAVE();
 367             return FALSE;
 368         }
 369         scrollbutton->need_timer = FALSE;
 370     }
 371     GDK_THREADS_LEAVE();
 372     return_val = gtk_vscrollbutton_scroll(scrollbutton);
 373     return return_val;
 374 }
 375
 376 static void gtk_vscrollbutton_set_sensitivity   (GtkAdjustment    *adjustment,
 377                                                  GtkVScrollbutton *scrollbutton)
 378 {
 379         if (!GTK_WIDGET_REALIZED(GTK_WIDGET(scrollbutton))) return;
 380         if (scrollbutton->button != 0) return; /* not while something is pressed */
 381
 382         gtk_widget_set_sensitive(scrollbutton->upbutton,
 383                                  (adjustment->value > adjustment->lower));
 384         gtk_widget_set_sensitive(scrollbutton->downbutton,
 385                                  (adjustment->value <  (adjustment->upper - adjustment->page_size)));
 386 }