Implementing completion combobox using touch-screen buttons

[Hiroyuki Tanaka]

Hi All,

I am trying to develop an application for a touch screen using buttons
for the numeric pad with Completion ComboBoxes.

At the moment I am having a problem sending the button presses to my
Completion ComboBox using sendkey.wait. From the keyboard (that will
not exist for my final application) I can enter text into my
Completion and the selection completes as expected.

In the attached demo program I can type using the keyboard

Type Selection Box shows
4 " 440 - Line 0"
44 " 440 - Line 0"
444 " 444 - Line 4"

However when I press the four button on my form I get.

Type Selection Box shows
4 " 440 - Line 0"
4 line clears

I assume that this is related to the fact that the focus is changing
from the ComboBox to the button during the press. Then I am forcing
the focus back to the Completion ComboBox. Not the same as typing
with a keyboard where the focus does not change.

What can I do so I can have both keyboard and button pressing to work
correctly in my Completion ComboBox? Is Sendkeys the way to go?

I have attached the shortest demo program I could develop. I hope
that this is suitable to demostrate my question.

Thanks for your time in reviewing my question. I have not been clear
please ask.

Tanaka

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

namespace keypad
{
public class mdtclientForm : System.Windows.Forms.Form
{
private System.ComponentModel.Container components = null;
private System.Windows.Forms.Button FourButton;
private CompletionComboBox CompletionComboBox;

private string strLostFocus;

public mdtclientForm()
{

InitializeComponent();
}
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
} base.Dispose( disposing );
}

#region Windows Form Designer generated code

private void InitializeComponent()
{
this.FourButton = new System.Windows.Forms.Button();
this.CompletionComboBox = new keypad.CompletionComboBox();
this.SuspendLayout();

this.FourButton.Location = new System.Drawing.Point(100, 150);
this.FourButton.Name = "FourButton";
this.FourButton.Size = new System.Drawing.Size(50, 45);
this.FourButton.TabIndex = 29;
this.FourButton.Text = "4";
this.FourButton.Click += new
System.EventHandler(this.NumericPad_Click);

this.CompletionComboBox.Location = new System.Drawing.Point(32,
88);
this.CompletionComboBox.Name = "CompletionComboBox";
this.CompletionComboBox.Size = new System.Drawing.Size(200, 21);
this.CompletionComboBox.TabIndex = 3;
this.CompletionComboBox.LostFocus += new
System.EventHandler(this.COMBOBOX_LostFocus);
this.CompletionComboBox.Text = "<Press Keys or Buttons>";
this.CompletionComboBox.Items.AddRange(new object[] {
"440 - Line 0",
"441 - Line 1",
"442 - Line 2",
"443 - Line 3",
"444 - Line 4 ",
"445 - Line 5",
"446 - Line 5"});
this.ClientSize = new System.Drawing.Size(292, 266);
this.Controls.Add(this.FourButton);
this.Controls.Add(this.CompletionComboBox);
this.Name = "Form1";
this.Text = "Form1";
this.ResumeLayout(false);
}
#endregion

[STAThread]
static void Main()
{
Application.Run(new mdtclientForm());
}

private void NumericPad_Click(object sender, System.EventArgs e)
{
foreach (Control controls in this.Controls)
{
if (controls.Name == strLostFocus)
{
if (Object.ReferenceEquals(controls.GetType(),
typeof(CompletionComboBox)))
{
CompletionComboBox mycontrol = new CompletionComboBox();
Button button = (Button) sender;
if(controls.CanFocus)
{
controls.Focus();
SendKeys.SendWait(button.Text);
}
}
}
}
}

private void COMBOBOX_LostFocus (object sender, System.EventArgs e)
{
CompletionComboBox comboBox = (CompletionComboBox) sender;
strLostFocus = comboBox.Name;
}
}

public class CompletionComboBox : ComboBox
{
public event System.ComponentModel.CancelEventHandler NotInList;

[Category("Behavior")]
public bool LimitToList
{
get { return _limitToList_; }
set { _limitToList_ = value; }
}

protected virtual void
OnNotInList(System.ComponentModel.CancelEventArgs e)
{
if (NotInList != null)
NotInList.Invoke(this, e);
}

protected override void
OnValidating(System.ComponentModel.CancelEventArgs e)
{
if (_limitToList_)
{
int pos = FindStringExact(Text);
if (pos == -1)
OnNotInList(e);
else
this.SelectedIndex = pos;
} base.OnValidating(e);
}

protected override void OnKeyDown(KeyEventArgs args)
{
_autoComplete_ = args.KeyCode != Keys.Delete && args.KeyCode !=
Keys.Back;
base.OnKeyDown(args);
}

protected override void OnTextChanged(EventArgs args)
{
if( _autoComplete_ )
{
string textEntered = Text;
int index = FindString(textEntered);
if( index >= 0 )
{
_autoComplete_ = false;
SelectedIndex = index;
_autoComplete_ = true;
Select(textEntered.Length, Text.Length);
}
} base.OnTextChanged(args);
}
private bool _autoComplete_ = true;
private bool _limitToList_ = true;
}
}