mcs/class/System.Windows.Forms/Gtk/ScrollBar.cs

   1 //
   2 // System.Windows.Forms.Button.cs
   3 //
   4 // Author:
   5 //   stubbed out by Jaak Simm (jaaksimm@firm.ee)
   6 //        implemented for Gtk+ by Philip Van Hoof (me@freax.org)
   7 //
   8 // (C) Ximian, Inc., 2002
   9 //
  10
  11 using System.Drawing;
  12
  13 namespace System.Windows.Forms {
  14
  15         /// <summary>
  16         /// </summary>
  17
  18         public class ScrollBar : Control {
  19                 internal Gtk.Adjustment adj;
  20                 private double val;
  21                 private double lower;
  22                 private double upper;
  23                 private double step_increment;
  24                 private double page_increment;
  25                 private double page_size;
  26
  27                 //
  28                 //  --- Constructor
  29                 //
  30
  31                 public ScrollBar() : base(){
  32                         // Defaults
  33                         this.upper = 100;
  34                         this.lower = 0;
  35                         this.val = 0;
  36                         this.step_increment = 1;
  37                         this.page_increment = 10;
  38                         this.page_size = 10;
  39                         this.adj = new Gtk.Adjustment(val, lower, upper, step_increment, page_increment, page_size);
  40                         //spec says tabstop defaults to false.
  41                         base.TabStop = false;
  42                         ConnectToChanged();
  43                 }
  44
  45                 //
  46                 //  --- Public Properties
  47                 //
  48
  49
  50                 public int LargeChange {
  51                         get {return (int)page_increment;}
  52                         set {
  53                                 if (value < 0){
  54                                         String st = String.Format (
  55                                                 "'{0}' is not a valid value for LargeChange."+
  56                                                 "It should be >= 0", value
  57                                         );
  58                                         throw new ArgumentException (st);
  59                                 }
  60                                 page_increment = value;
  61                                 UpdateGtkScroll();
  62                         }
  63                 }
  64
  65                 public int Maximum {
  66                         get {return (int) upper;}
  67                         set {
  68                                 upper = value;
  69                                 if (value < lower)
  70                                         lower = value;
  71                                 if (value < this.Value)
  72                                         this.Value = value;
  73
  74                                 UpdateGtkScroll();
  75                         }
  76                 }
  77
  78                 public int Minimum {
  79                         get {return (int) lower;}
  80                         set {
  81                                 lower = value;
  82                                 if (value > upper)
  83                                         upper = value;
  84                                 if (value > val)
  85                                         val = value;
  86                                 UpdateGtkScroll();
  87                         }
  88                 }
  89                 public int SmallChange {
  90                         get { return (int) step_increment;}
  91                         set {
  92                                 if (value < 0){
  93                                         String st = String.Format (
  94                                                 "'{0}' is not a valid value for SmallChange."+
  95                                                 "It should be >= 0", value
  96                                         );
  97                                         throw new ArgumentException (st);
  98                                 }
  99                                 step_increment = value;
 100                                 UpdateGtkScroll();
 101                         }
 102                 }
 103
 104                 public int Value {
 105                         get {return (int) val; }
 106
 107                         set {
 108                                 if ((value > upper) || (value < lower)){
 109                                         String st = String.Format (
 110                                         "'{0}' is not a valid value for Minimum."+
 111                                         " It should be betwen Minimum and Maximum", value);
 112
 113                                         throw new ArgumentException (st);
 114                                 }
 115                                 val = value;
 116                                 UpdateGtkScroll();
 117                         }
 118                 }
 119
 120                 //
 121                 //  --- Public Events
 122                 //
 123
 124                 public event ScrollEventHandler Scroll;
 125                 public event EventHandler ValueChanged;
 126
 127                 protected virtual void OnValueChanged (EventArgs args){
 128                         if (ValueChanged != null)
 129                                 ValueChanged (this, args);
 130                 }
 131                 protected virtual void OnScroll (ScrollEventArgs args){
 132                         if (Scroll != null)
 133                                 Scroll (this, args);
 134                 }
 135                 [MonoTODO]
 136                 protected override void OnEnabledChanged(EventArgs e){
 137                         throw new NotImplementedException();
 138                 }
 139
 140                 [MonoTODO]
 141                 protected override void OnHandleCreated(EventArgs e){
 142                         throw new NotImplementedException();
 143                 }
 144
 145                 // FIXME:
 146
 147                 internal protected void changed_cb (object o, EventArgs args){
 148                         val = this.adj.Value;
 149                         OnValueChanged(args);
 150                         OnScroll (new ScrollEventArgs(ScrollEventType.ThumbPosition ,(int) val));
 151                 }
 152
 153                 internal protected void ConnectToChanged (){
 154                         this.adj.ValueChanged += new EventHandler (changed_cb);
 155                 }
 156
 157                 internal protected void UpdateGtkScroll(){
 158                         this.adj.SetBounds (lower, upper, step_increment, page_increment, page_size);
 159                         if ((int) val != this.adj.Value)
 160                                 this.adj.Value = (int) val;
 161                 }
 162          }
 163 }