Lazarus
Home
Help
TinyPortal
Search
Login
Register
Lazarus
»
Forum
»
Programming
»
LCL
»
[SOLVED] Undoing text editing in TEdit, etc.
Free Pascal
Website
Downloads
Wiki
Bugtracker
Mailing List
Lazarus
Website
Downloads (Laz+FPC)
Packages (OPM)
FAQ
Wiki
Bugtracker
IRC channel
Latest SVN
Mailing List
Other languages
Foundation
Website
Useful Wiki Links
Project Roadmap
Getting the Source
Screenshots
How to use the forum
About donations (wiki)
Bookstore
Computer Math and Games in Pascal
(preview)
Lazarus Handbook
Search
Advanced search
Recent
More componenets.
by
trev
[
Today
at 12:07:31 am]
Problem with xor-el crypt...
by
xinyiman
[
Today
at 12:04:40 am]
TIpHtmlPanel and backgrou...
by
wp
[March 01, 2021, 11:32:49 pm]
Lazarus Release 2.0.12
by
Bloodbat
[March 01, 2021, 10:52:00 pm]
Problem with receiving ev...
by
skalogryz
[March 01, 2021, 10:36:46 pm]
FPC on Rasp Pi, non Lazar...
by
AlanTheBeast
[March 01, 2021, 10:31:20 pm]
Get palette
by
justnewbie
[March 01, 2021, 10:10:51 pm]
Configure data source via...
by
andersonscinfo
[March 01, 2021, 09:55:08 pm]
FFGrab4Laz = How to recor...
by
BosseB
[March 01, 2021, 09:42:38 pm]
linux x64 assembler
by
mika
[March 01, 2021, 09:11:16 pm]
« previous
next »
Print
Pages: [
1
]
Author
Topic: [SOLVED] Undoing text editing in TEdit, etc. (Read 424 times)
egsuh
Hero Member
Posts: 625
[SOLVED] Undoing text editing in TEdit, etc.
«
on:
September 18, 2019, 11:48:52 am »
Is it possible to undo editings in TEdit, etc.?
For example, the original Edit1.Text = 'Edit1'. And I tried to change some part of it, but I want to leave the EditBox just leaving the original 'Edit1' text, ignoring my own changes?
«
Last Edit: September 18, 2019, 12:13:33 pm by egsuh
»
Logged
wp
Hero Member
Posts: 8097
Re: Undoing text editing in TEdit, etc.
«
Reply #1 on:
September 18, 2019, 12:07:07 pm »
Press ESC to restore the original content. I think it is not ready-made, but you can easily add it by yourself:
Add a string variable to the form named FOldEdit1Text
Write a handler for Edit1's OnEnter event copying is Text to FOldEdit1Text.
Write a handler for Edit1's OnKeyDown event checking the pressed key for ESCAPE and replacing the Text by FOldEdit1Text.
Code: Pascal
[Select]
[+]
[-]
unit
Unit1
;
{$mode objfpc}{$H+}
interface
uses
Classes
,
SysUtils
,
Forms
,
Controls
,
Graphics
,
Dialogs
,
StdCtrls
;
type
{ TForm1 }
TForm1
=
class
(
TForm
)
Edit1
:
TEdit
;
Edit2
:
TEdit
;
procedure
Edit1Enter
(
Sender
:
TObject
)
;
procedure
Edit1KeyDown
(
Sender
:
TObject
;
var
Key
:
Word
;
Shift
:
TShiftState
)
;
procedure
Edit2Enter
(
Sender
:
TObject
)
;
procedure
Edit2KeyDown
(
Sender
:
TObject
;
var
Key
:
Word
;
Shift
:
TShiftState
)
;
private
FOldEdit1Text
:
String
;
FOldEdit2Text
:
String
;
public
end
;
var
Form1
:
TForm1
;
implementation
{$R *.lfm}
uses
LCLType
;
{ TForm1 }
procedure
TForm1
.
Edit1Enter
(
Sender
:
TObject
)
;
begin
FOldEdit1Text
:
=
Edit1
.
Text
;
end
;
procedure
TForm1
.
Edit1KeyDown
(
Sender
:
TObject
;
var
Key
:
Word
;
Shift
:
TShiftState
)
;
begin
if
Key
=
VK_ESCAPE
then
begin
Edit1
.
Text
:
=
FOldEdit1Text
;
Edit1
.
SelectAll
;
Key
:
=
0
;
end
;
end
;
procedure
TForm1
.
Edit2Enter
(
Sender
:
TObject
)
;
begin
FOldEdit2Text
:
=
Edit2
.
Text
;
end
;
procedure
TForm1
.
Edit2KeyDown
(
Sender
:
TObject
;
var
Key
:
Word
;
Shift
:
TShiftState
)
;
begin
if
Key
=
VK_ESCAPE
then
begin
Edit2
.
Text
:
=
FOldEdit2Text
;
Edit2
.
SelectAll
;
Key
:
=
0
;
end
;
end
;
end
.
Logged
Mainly Lazarus trunk / fpc 3.2.0 / all 32-bit on Win-10, but many more...
egsuh
Hero Member
Posts: 625
Re: Undoing text editing in TEdit, etc.
«
Reply #2 on:
September 18, 2019, 12:13:06 pm »
@wp
I see. The function is not built-in. Writing such codes is not big deal.
Logged
Print
Pages: [
1
]
« previous
next »
Lazarus
»
Forum
»
Programming
»
LCL
»
[SOLVED] Undoing text editing in TEdit, etc.
TinyPortal
© 2005-2018