Pileus Git - ~andy/gtk/blob - gtk/gtkadjustment.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 2 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, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19
  20 /*
  21  * Modified by the GTK+ Team and others 1997-1999.  See the AUTHORS
  22  * file for a list of people on the GTK+ Team.  See the ChangeLog
  23  * files for a list of changes.  These files are distributed with
  24  * GTK+ at ftp://ftp.gtk.org/pub/gtk/.
  25  */
  26
  27 #include "gtkadjustment.h"
  28 #include "gtksignal.h"
  29
  30
  31 enum {
  32   CHANGED,
  33   VALUE_CHANGED,
  34   LAST_SIGNAL
  35 };
  36
  37
  38 static void gtk_adjustment_class_init (GtkAdjustmentClass *klass);
  39 static void gtk_adjustment_init       (GtkAdjustment      *adjustment);
  40
  41
  42 static guint adjustment_signals[LAST_SIGNAL] = { 0 };
  43
  44
  45 GtkType
  46 gtk_adjustment_get_type (void)
  47 {
  48   static GtkType adjustment_type = 0;
  49
  50   if (!adjustment_type)
  51     {
  52       static const GtkTypeInfo adjustment_info =
  53       {
  54         "GtkAdjustment",
  55         sizeof (GtkAdjustment),
  56         sizeof (GtkAdjustmentClass),
  57         (GtkClassInitFunc) gtk_adjustment_class_init,
  58         (GtkObjectInitFunc) gtk_adjustment_init,
  59         /* reserved_1 */ NULL,
  60         /* reserved_2 */ NULL,
  61         (GtkClassInitFunc) NULL,
  62       };
  63
  64       adjustment_type = gtk_type_unique (GTK_TYPE_DATA, &adjustment_info);
  65     }
  66
  67   return adjustment_type;
  68 }
  69
  70 static void
  71 gtk_adjustment_class_init (GtkAdjustmentClass *class)
  72 {
  73   GtkObjectClass *object_class;
  74
  75   object_class = (GtkObjectClass*) class;
  76
  77   adjustment_signals[CHANGED] =
  78     gtk_signal_new ("changed",
  79                     GTK_RUN_FIRST | GTK_RUN_NO_RECURSE,
  80                     GTK_CLASS_TYPE (object_class),
  81                     GTK_SIGNAL_OFFSET (GtkAdjustmentClass, changed),
  82                     gtk_marshal_NONE__NONE,
  83                     GTK_TYPE_NONE, 0);
  84   adjustment_signals[VALUE_CHANGED] =
  85     gtk_signal_new ("value_changed",
  86                     GTK_RUN_FIRST | GTK_RUN_NO_RECURSE,
  87                     GTK_CLASS_TYPE (object_class),
  88                     GTK_SIGNAL_OFFSET (GtkAdjustmentClass, value_changed),
  89                     gtk_marshal_NONE__NONE,
  90                     GTK_TYPE_NONE, 0);
  91
  92   gtk_object_class_add_signals (object_class, adjustment_signals, LAST_SIGNAL);
  93
  94   class->changed = NULL;
  95   class->value_changed = NULL;
  96 }
  97
  98 static void
  99 gtk_adjustment_init (GtkAdjustment *adjustment)
 100 {
 101   adjustment->value = 0.0;
 102   adjustment->lower = 0.0;
 103   adjustment->upper = 0.0;
 104   adjustment->step_increment = 0.0;
 105   adjustment->page_increment = 0.0;
 106   adjustment->page_size = 0.0;
 107 }
 108
 109 GtkObject*
 110 gtk_adjustment_new (gfloat value,
 111                     gfloat lower,
 112                     gfloat upper,
 113                     gfloat step_increment,
 114                     gfloat page_increment,
 115                     gfloat page_size)
 116 {
 117   GtkAdjustment *adjustment;
 118
 119   adjustment = gtk_type_new (gtk_adjustment_get_type ());
 120
 121   adjustment->value = value;
 122   adjustment->lower = lower;
 123   adjustment->upper = upper;
 124   adjustment->step_increment = step_increment;
 125   adjustment->page_increment = page_increment;
 126   adjustment->page_size = page_size;
 127
 128   return GTK_OBJECT (adjustment);
 129 }
 130
 131 void
 132 gtk_adjustment_set_value (GtkAdjustment        *adjustment,
 133                           gfloat                value)
 134 {
 135   g_return_if_fail (adjustment != NULL);
 136   g_return_if_fail (GTK_IS_ADJUSTMENT (adjustment));
 137
 138   value = CLAMP (value, adjustment->lower, adjustment->upper);
 139
 140   if (value != adjustment->value)
 141     {
 142       adjustment->value = value;
 143
 144       gtk_adjustment_value_changed (adjustment);
 145     }
 146 }
 147
 148 void
 149 gtk_adjustment_changed (GtkAdjustment        *adjustment)
 150 {
 151   g_return_if_fail (adjustment != NULL);
 152   g_return_if_fail (GTK_IS_ADJUSTMENT (adjustment));
 153
 154   gtk_signal_emit (GTK_OBJECT (adjustment), adjustment_signals[CHANGED]);
 155 }
 156
 157 void
 158 gtk_adjustment_value_changed (GtkAdjustment        *adjustment)
 159 {
 160   g_return_if_fail (adjustment != NULL);
 161   g_return_if_fail (GTK_IS_ADJUSTMENT (adjustment));
 162
 163   gtk_signal_emit (GTK_OBJECT (adjustment), adjustment_signals[VALUE_CHANGED]);
 164 }
 165
 166 void
 167 gtk_adjustment_clamp_page (GtkAdjustment *adjustment,
 168                            gfloat         lower,
 169                            gfloat         upper)
 170 {
 171   gint need_emission;
 172
 173   g_return_if_fail (adjustment != NULL);
 174   g_return_if_fail (GTK_IS_ADJUSTMENT (adjustment));
 175
 176   lower = CLAMP (lower, adjustment->lower, adjustment->upper);
 177   upper = CLAMP (upper, adjustment->lower, adjustment->upper);
 178
 179   need_emission = FALSE;
 180
 181   if (adjustment->value + adjustment->page_size < upper)
 182     {
 183       adjustment->value = upper - adjustment->page_size;
 184       need_emission = TRUE;
 185     }
 186   if (adjustment->value > lower)
 187     {
 188       adjustment->value = lower;
 189       need_emission = TRUE;
 190     }
 191
 192   if (need_emission)
 193     gtk_adjustment_value_changed (adjustment);
 194 }