ControlFocus
  1using System ;
  2using System.ComponentModel ;
  3using System.Collections ;
  4using System.Diagnostics ;
  5using System.Windows.Forms ;
  6using System.Drawing ;
  7using System.Drawing.Drawing2D ;
  8
  9namespace Shark
 10{
 11    
 12    [ProvideProperty( "NextControl", typeof(Component)) ]
 13    [ProvideProperty( "PreviousControl", typeof(Component)) ]
 14    public class ControlFocus:Component, IExtenderProvider
 15    {
 16        public ControlFocus()
 17        {
 18            //
 19            // TODO: Add constructor logic here
 20            //
 21        }
 22        Hashtable _hashTable = new Hashtable();
 23        Hashtable _previousHashTable = new Hashtable();
 24
 25        public Keys NextK;
 26        public Keys PreviousK;
 27
 28        public void SetNextControl(Component component,Control c)
 29        {
 30            if ( _hashTable.Contains( component ) != true)
 31            {
 32                //MessageBox.Show(component.ToString());
 33                _hashTable.Add(component,c);
 34                Control currentC = (Control)component;
 35                currentC.KeyDown +=new KeyEventHandler(currentC_KeyDown);
 36            }
 37            else
 38            {
 39                _hashTable[component] = c;
 40            }
 41        }
 42        public Control GetNextControl(Component component)
 43        {
 44            if( _hashTable.Contains( component ))
 45            {
 46                return (Control)_hashTable[ component ];
 47            }
 48            return null;
 49        }
 50
 51
 52        public void SetPreviousControl(Component component,Control c)
 53        {
 54            if ( _previousHashTable.Contains( component ) != true)
 55            {
 56                //MessageBox.Show(component.ToString());
 57                _previousHashTable.Add(component,c);
 58                Control currentC = (Control)component;
 59                currentC.KeyDown +=new KeyEventHandler(currentC_KeyDown);
 60            }
 61            else
 62            {
 63                _previousHashTable[component] = c;
 64            }
 65        }
 66        
 67        public Control GetPreviousControl(Component component)
 68        {
 69            if( _previousHashTable.Contains( component ))
 70            {
 71                return (Control)_previousHashTable[ component ];
 72            }
 73            return null;
 74        }
 75
 76        /**//// <summary>
 77        /// Used to retrieve the MenuImage extender property value
 78        /// for a given <c>MenuItem</c> component instance.
 79        /// </summary>
 80        /// <param name="component">the menu item instance associated with the value</param>
 81        /// <returns>Returns the MenuImage index property value for the specified <c>MenuItem</c> component instance.</returns>
 82        public string GetControlFocus( Component component )
 83        {
 84            if( _hashTable.Contains( component ))
 85                return (string) _hashTable[ component ] ;
 86
 87            return null;
 88        }
 89
 90        public ControlFocus(System.ComponentModel.IContainer container)
 91        {
 92            container.Add(this);
 93        }
 94        public bool CanExtend( object component )
 95        {
 96            // only support MenuItem objects that are not
 97            // top-level menus (default rendering for top-level
 98            // menus is fine - does not need extension
 99            if ( component is Control &&  !(component is Form))
100            {
101                return true;
102            }
103                
104            return false ;
105        }
106
107
108        private void currentC_KeyDown(object sender, KeyEventArgs e)
109        {
110            if(e.KeyCode == this.NextK)
111            {
112                Control nextControl = this.GetNextControl( (Component)sender);
113                if(nextControl != null && nextControl.CanFocus)
114                    nextControl.Focus();
115            }
116            else if(e.KeyCode == this.PreviousK)
117            {
118                Control previousControl = this.GetPreviousControl( (Component)sender);
119                if(previousControl != null && previousControl.CanFocus)
120                    previousControl.Focus();
121            }
122        }
123
124
125    }
126}
127