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         (GtkArgSetFunc) NULL,
  52         (GtkArgGetFunc) NULL,
  53       };
  54
  55       adjustment_type = gtk_type_unique (gtk_data_get_type (), &adjustment_info);
  56     }
  57
  58   return adjustment_type;
  59 }
  60
  61 static void
  62 gtk_adjustment_class_init (GtkAdjustmentClass *class)
  63 {
  64   GtkObjectClass *object_class;
  65
  66   object_class = (GtkObjectClass*) class;
  67
  68   adjustment_signals[CHANGED] =
  69     gtk_signal_new ("changed",
  70                     GTK_RUN_FIRST | GTK_RUN_NO_RECURSE,
  71                     object_class->type,
  72                     GTK_SIGNAL_OFFSET (GtkAdjustmentClass, changed),
  73                     gtk_signal_default_marshaller,
  74                     GTK_TYPE_NONE, 0);
  75   adjustment_signals[VALUE_CHANGED] =
  76     gtk_signal_new ("value_changed",
  77                     GTK_RUN_FIRST | GTK_RUN_NO_RECURSE,
  78                     object_class->type,
  79                     GTK_SIGNAL_OFFSET (GtkAdjustmentClass, value_changed),
  80                     gtk_signal_default_marshaller,
  81                     GTK_TYPE_NONE, 0);
  82
  83   gtk_object_class_add_signals (object_class, adjustment_signals, LAST_SIGNAL);
  84
  85   class->changed = NULL;
  86   class->value_changed = NULL;
  87 }
  88
  89 static void
  90 gtk_adjustment_init (GtkAdjustment *adjustment)
  91 {
  92   adjustment->value = 0.0;
  93   adjustment->lower = 0.0;
  94   adjustment->upper = 0.0;
  95   adjustment->step_increment = 0.0;
  96   adjustment->page_increment = 0.0;
  97   adjustment->page_size = 0.0;
  98 }
  99
 100 GtkObject*
 101 gtk_adjustment_new (gfloat value,
 102                     gfloat lower,
 103                     gfloat upper,
 104                     gfloat step_increment,
 105                     gfloat page_increment,
 106                     gfloat page_size)
 107 {
 108   GtkAdjustment *adjustment;
 109
 110   adjustment = gtk_type_new (gtk_adjustment_get_type ());
 111
 112   adjustment->value = value;
 113   adjustment->lower = lower;
 114   adjustment->upper = upper;
 115   adjustment->step_increment = step_increment;
 116   adjustment->page_increment = page_increment;
 117   adjustment->page_size = page_size;
 118
 119   return GTK_OBJECT (adjustment);
 120 }
 121
 122 void
 123 gtk_adjustment_set_value (GtkAdjustment        *adjustment,
 124                           gfloat                value)
 125 {
 126   g_return_if_fail (adjustment != NULL);
 127   g_return_if_fail (GTK_IS_ADJUSTMENT (adjustment));
 128
 129   value = CLAMP (value, adjustment->lower, adjustment->upper);
 130
 131   if (value != adjustment->value)
 132     {
 133       adjustment->value = value;
 134
 135       gtk_adjustment_value_changed (adjustment);
 136     }
 137 }
 138
 139 void
 140 gtk_adjustment_changed (GtkAdjustment        *adjustment)
 141 {
 142   g_return_if_fail (adjustment != NULL);
 143   g_return_if_fail (GTK_IS_ADJUSTMENT (adjustment));
 144
 145   gtk_signal_emit (GTK_OBJECT (adjustment), adjustment_signals[CHANGED]);
 146 }
 147
 148 void
 149 gtk_adjustment_value_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[VALUE_CHANGED]);
 155 }
 156
 157 void
 158 gtk_adjustment_clamp_page (GtkAdjustment *adjustment,
 159                            gfloat         lower,
 160                            gfloat         upper)
 161 {
 162   gint need_emission;
 163
 164   g_return_if_fail (adjustment != NULL);
 165   g_return_if_fail (GTK_IS_ADJUSTMENT (adjustment));
 166
 167   lower = CLAMP (lower, adjustment->lower, adjustment->upper);
 168   upper = CLAMP (upper, adjustment->lower, adjustment->upper);
 169
 170   need_emission = FALSE;
 171
 172   if (adjustment->value + adjustment->page_size < upper)
 173     {
 174       adjustment->value = upper - adjustment->page_size;
 175       need_emission = TRUE;
 176     }
 177   if (adjustment->value > lower)
 178     {
 179       adjustment->value = lower;
 180       need_emission = TRUE;
 181     }
 182
 183   if (need_emission)
 184     gtk_adjustment_value_changed (adjustment);
 185 }