Author: Tomas Rutkauskas

I would like to pop up a TComboBox at the caret position on a TMemo when the key 
that is pressed is a full stop (.). Has anyone got any code for this?

Answer:

1   unit CBoxInMemo;
2   
3   interface
4   
5   uses
6     Windows, Classes, Controls, Graphics, Forms, StdCtrls;
7   
8   type
9     TFrmCboxInMemo = class(TForm)
10      Button1: TButton;
11      Memo1: TMemo;
12      Label1: TLabel;
13      ComboBox1: TComboBox;
14      procedure Button1Click(Sender: TObject);
15      procedure ComboBox1Exit(Sender: TObject);
16      procedure ComboBox1Click(Sender: TObject);
17    private
18      { Private declarations }
19    public
20      { Public declarations }
21    end;
22  
23  var
24    FrmCboxInMemo: TFrmCboxInMemo;
25  
26  implementation
27  
28  {$R *.DFM}
29  
30  procedure TFrmCboxInMemo.Button1Click(Sender: TObject);
31  var
32    clientPos: TPoint;
33    lineHeight: Integer;
34    tmpFont: TFont;
35  begin
36    GetCaretPos(clientPos);
37    {Use the following calculation of line height only if you want your combobox
38    to appear below the char position you are referencing.}
39    tmpFont := Canvas.Font;
40    Canvas.Font := Memo1.Font;
41    lineHeight := Canvas.TextHeight('Xy');
42    Canvas.Font := tmpFont;
43    with ComboBox1 do
44    begin
45      {Adjustment of Top by lineHeight only necessary if combobox is to appear below 
46  line.}
47      Top := clientPos.Y + Memo1.Top + lineHeight;
48      Left := clientPos.X + Memo1.Left;
49      Visible := true;
50      SetFocus;
51    end;
52  end;
53  
54  procedure TFrmCboxInMemo.ComboBox1Exit(Sender: TObject);
55  begin
56    ComboBox1.Visible := false;
57  end;
58  
59  procedure TFrmCboxInMemo.ComboBox1Click(Sender: TObject);
60  begin
61    ComboBox1.Visible := false;
62  end;
63  
64  end.