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 #include "gtkadjustment.h"
  20 #include "gtksignal.h"
  21
  22
  23 enum {
  24   CHANGED,
  25   VALUE_CHANGED,
  26   LAST_SIGNAL
  27 };
  28
  29
  30 static void gtk_adjustment_class_init (GtkAdjustmentClass *klass);
  31 static void gtk_adjustment_init       (GtkAdjustment      *adjustment);
  32
  33
  34 static guint adjustment_signals[LAST_SIGNAL] = { 0 };
  35
  36
  37 GtkType
  38 gtk_adjustment_get_type (void)
  39 {
  40   static GtkType adjustment_type = 0;
  41
  42   if (!adjustment_type)
  43     {
  44       GtkTypeInfo adjustment_info =
  45       {
  46         "GtkAdjustment",
  47         sizeof (GtkAdjustment),
  48         sizeof (GtkAdjustmentClass),
  49         (GtkClassInitFunc) gtk_adjustment_class_init,
  50         (GtkObjectInitFunc) gtk_adjustment_init,
  51         /* reserved_1 */ NULL,
  52         /* reserved_2 */ NULL,
  53         (GtkClassInitFunc) NULL,
  54       };
  55
  56       adjustment_type = gtk_type_unique (GTK_TYPE_DATA, &adjustment_info);
  57     }
  58
  59   return adjustment_type;
  60 }
  61
  62 static void
  63 gtk_adjustment_class_init (GtkAdjustmentClass *class)
  64 {
  65   GtkObjectClass *object_class;
  66
  67   object_class = (GtkObjectClass*) class;
  68
  69   adjustment_signals[CHANGED] =
  70     gtk_signal_new ("changed",
  71                     GTK_RUN_FIRST | GTK_RUN_NO_RECURSE,
  72                     object_class->type,
  73                     GTK_SIGNAL_OFFSET (GtkAdjustmentClass, changed),
  74                     gtk_signal_default_marshaller,
  75                     GTK_TYPE_NONE, 0);
  76   adjustment_signals[VALUE_CHANGED] =
  77     gtk_signal_new ("value_changed",
  78                     GTK_RUN_FIRST | GTK_RUN_NO_RECURSE,
  79                     object_class->type,
  80                     GTK_SIGNAL_OFFSET (GtkAdjustmentClass, value_changed),
  81                     gtk_signal_default_marshaller,
  82                     GTK_TYPE_NONE, 0);
  83
  84   gtk_object_class_add_signals (object_class, adjustment_signals, LAST_SIGNAL);
  85
  86   class->changed = NULL;
  87   class->value_changed = NULL;
  88 }
  89
  90 static void
  91 gtk_adjustment_init (GtkAdjustment *adjustment)
  92 {
  93   adjustment->value = 0.0;
  94   adjustment->lower = 0.0;
  95   adjustment->upper = 0.0;
  96   adjustment->step_increment = 0.0;
  97   adjustment->page_increment = 0.0;
  98   adjustment->page_size = 0.0;
  99 }
 100
 101 GtkObject*
 102 gtk_adjustment_new (gfloat value,
 103                     gfloat lower,
 104                     gfloat upper,
 105                     gfloat step_increment,
 106                     gfloat page_increment,
 107                     gfloat page_size)
 108 {
 109   GtkAdjustment *adjustment;
 110
 111   adjustment = gtk_type_new (gtk_adjustment_get_type ());
 112
 113   adjustment->value = value;
 114   adjustment->lower = lower;
 115   adjustment->upper = upper;
 116   adjustment->step_increment = step_increment;
 117   adjustment->page_increment = page_increment;
 118   adjustment->page_size = page_size;
 119
 120   return GTK_OBJECT (adjustment);
 121 }
 122
 123 void
 124 gtk_adjustment_set_value (GtkAdjustment        *adjustment,
 125                           gfloat                value)
 126 {
 127   g_return_if_fail (adjustment != NULL);
 128   g_return_if_fail (GTK_IS_ADJUSTMENT (adjustment));
 129
 130   value = CLAMP (value, adjustment->lower, adjustment->upper);
 131
 132   if (value != adjustment->value)
 133     {
 134       adjustment->value = value;
 135
 136       gtk_adjustment_value_changed (adjustment);
 137     }
 138 }
 139
 140 void
 141 gtk_adjustment_changed (GtkAdjustment        *adjustment)
 142 {
 143   g_return_if_fail (adjustment != NULL);
 144   g_return_if_fail (GTK_IS_ADJUSTMENT (adjustment));
 145
 146   gtk_signal_emit (GTK_OBJECT (adjustment), adjustment_signals[CHANGED]);
 147 }
 148
 149 void
 150 gtk_adjustment_value_changed (GtkAdjustment        *adjustment)
 151 {
 152   g_return_if_fail (adjustment != NULL);
 153   g_return_if_fail (GTK_IS_ADJUSTMENT (adjustment));
 154
 155   gtk_signal_emit (GTK_OBJECT (adjustment), adjustment_signals[VALUE_CHANGED]);
 156 }
 157
 158 void
 159 gtk_adjustment_clamp_page (GtkAdjustment *adjustment,
 160                            gfloat         lower,
 161                            gfloat         upper)
 162 {
 163   gint need_emission;
 164
 165   g_return_if_fail (adjustment != NULL);
 166   g_return_if_fail (GTK_IS_ADJUSTMENT (adjustment));
 167
 168   lower = CLAMP (lower, adjustment->lower, adjustment->upper);
 169   upper = CLAMP (upper, adjustment->lower, adjustment->upper);
 170
 171   need_emission = FALSE;
 172
 173   if (adjustment->value + adjustment->page_size < upper)
 174     {
 175       adjustment->value = upper - adjustment->page_size;
 176       need_emission = TRUE;
 177     }
 178   if (adjustment->value > lower)
 179     {
 180       adjustment->value = lower;
 181       need_emission = TRUE;
 182     }
 183
 184   if (need_emission)
 185     gtk_adjustment_value_changed (adjustment);
 186 }