Title: How do I click an empty listbox?
Question: Normally you cannot click an empty box- the application in this article allows this
Answer:
The application below is a buzzword generator- click a button and it will generate a phrase of 1-4 words (you select the length). There are 4 lists and you can add words by clicking on an empty part of the list. To delete any existing word just click the word. The lists are automatically saved out and reloaded when the application is run
unit genword;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls, ExtCtrls;
type
TForm1 = class(TForm)
ListBox1: TListBox;
ListBox2: TListBox;
ListBox3: TListBox;
ListBox4: TListBox;
CheckBox1: TCheckBox;
CheckBox2: TCheckBox;
CheckBox3: TCheckBox;
CheckBox4: TCheckBox;
Edit1: TEdit;
Button1: TButton;
procedure FormCreate(Sender: TObject);
procedure FormActivate(Sender: TObject);
procedure FormDestroy(Sender: TObject);
procedure AddWords(Sender: TObject);
procedure Button1Click(Sender: TObject);
procedure ListBox1MouseDown(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
private
{ Private declarations }
public
Aftercreate : boolean;
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.DFM}
procedure TForm1.FormCreate(Sender: TObject);
begin
Aftercreate := true;
randomize;
end;
procedure TForm1.FormActivate(Sender: TObject);
begin
if AFtercreate then
begin
Aftercreate := false;
if fileexists('1st.txt') then listbox1.Items.LoadFromFile('1st.txt');
if fileexists('2nd.txt') then listbox2.Items.LoadFromFile('2nd.txt');
if fileexists('3rd.txt') then listbox3.Items.LoadFromFile('3rd.txt');
if fileexists('4th.txt') then listbox4.Items.LoadFromFile('4th.txt');
end;
end;
procedure TForm1.FormDestroy(Sender: TObject);
begin
if listbox1.items.count 0 then listbox1.items.savetofile('1st.txt');
if listbox2.items.count 0 then listbox2.items.savetofile('2nd.txt');
if listbox3.items.count 0 then listbox3.items.savetofile('3rd.txt');
if listbox4.items.count 0 then listbox4.items.savetofile('4th.txt');
end;
procedure TForm1.AddWords(Sender: TObject);
var str : string;
boxnum : integer;
begin
Str := '';
boxnum := (sender as tlistbox).tag;
str:= inputbox('Enter new word','New Word',Str);
if trim(str) '' then
begin
case boxnum of
0:listbox1.items.add(str);
1:listbox2.items.add(str);
2:listbox3.items.add(str);
3:listbox4.items.add(str);
end;
end;
end;
function Randword(Box : tlistbox):string;
var Index : integer;
begin
Index := random(box.items.count);
result := box.Items[Index];
end;
procedure TForm1.Button1Click(Sender: TObject);
var str,str1,Str2,Str3,Str4 : string;
begin
str1 := '';
str2 := '';
str3 := '';
str4 := '';
if checkbox1.checked and (listbox1.items.count0) then
str1 := RandWord(listbox1);
if checkbox2.checked and (listbox2.items.count0) then
str2 := RandWord(listbox2);
if checkbox3.checked and (listbox3.items.count0) then
str3 := RandWord(listbox3);
if checkbox4.checked and (listbox4.items.count0) then
str4 := RandWord(listbox4);
if str1 '' then Str := Str1;
if str2 '' then Str := Str +' '+ Str2;
if str3 '' then Str := Str +' '+ Str3;
if str4 '' then Str := Str +' '+ Str4;
edit1.text := str;
Str := '';
if str1 '' then Str := Str1[1];
if str2 '' then Str := Str + Str2[1];
if str3 '' then Str := Str + Str3[1];
if str4 '' then Str := Str + Str4[1];
edit1.text := edit1.text +' ('+str+')';
end;
function Confirm(S:string):boolean;
begin
Result := MessageDlg(S+'?', mtConfirmation, [mbYes, mbNo], 0)= Mryes;
end;
procedure TForm1.ListBox1MouseDown(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
var selIndex : integer;
str : string;
p : Tpoint;
begin
p.X := X;
P.y := Y;
SelIndex:= (sender as Tlistbox).ItemAtPos(p,true);
If SelIndex =-1 then
AddWords(sender)
else
begin
str := (sender as tlistbox).items[SelIndex];
if Confirm('Delete '+str) then
(Sender as Tlistbox).Items.Delete(SelIndex);
end;
end;
end.
object Form1: TForm1
Left = 313
Top = 243
Width = 682
Height = 343
Caption = 'title Generator'
Color = clBtnFace
Font.Charset = DEFAULT_CHARSET
Font.Color = clWindowText
Font.Height = -11
Font.Name = 'MS Sans Serif'
Font.Style = []
OldCreateOrder = False
OnActivate = FormActivate
OnCreate = FormCreate
OnDestroy = FormDestroy
PixelsPerInch = 96
TextHeight = 13
object ListBox1: TListBox
Left = 48
Top = 42
Width = 127
Height = 173
IntegralHeight = True
ItemHeight = 13
Items.Strings = (
'Oberon')
TabOrder = 0
OnMouseDown = ListBox1MouseDown
end
object ListBox2: TListBox
Tag = 1
Left = 186
Top = 42
Width = 127
Height = 173
IntegralHeight = True
ItemHeight = 13
TabOrder = 1
OnMouseDown = ListBox1MouseDown
end
object ListBox3: TListBox
Tag = 2
Left = 318
Top = 42
Width = 127
Height = 173
IntegralHeight = True
ItemHeight = 13
TabOrder = 2
OnMouseDown = ListBox1MouseDown
end
object ListBox4: TListBox
Tag = 3
Left = 456
Top = 42
Width = 127
Height = 173
IntegralHeight = True
ItemHeight = 13
TabOrder = 3
OnMouseDown = ListBox1MouseDown
end
object CheckBox1: TCheckBox
Left = 54
Top = 222
Width = 97
Height = 17
Caption = '1st'
Checked = True
State = cbChecked
TabOrder = 4
end
object CheckBox2: TCheckBox
Left = 186
Top = 222
Width = 97
Height = 17
Caption = '2nd'
Checked = True
State = cbChecked
TabOrder = 5
end
object CheckBox3: TCheckBox
Left = 318
Top = 222
Width = 97
Height = 17
Caption = '3rd'
Checked = True
State = cbChecked
TabOrder = 6
end
object CheckBox4: TCheckBox
Left = 456
Top = 222
Width = 97
Height = 17
Caption = '4th'
Checked = True
State = cbChecked
TabOrder = 7
end
object Edit1: TEdit
Left = 54
Top = 252
Width = 523
Height = 21
TabOrder = 8
end
object Button1: TButton
Left = 588
Top = 252
Width = 75
Height = 25
Caption = 'Go'
TabOrder = 9
OnClick = Button1Click
end
end