Mega Code Archive
How do I intercept the OnPaste event in a TMemo
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Title: How do I intercept the OnPaste event in a TMemo
First, read the FAQ describing how to create a simple Delphi component. Then, you are ready to procced with this component.
CODE
unit MemoEx;
interface
uses
ClipBrd, Windows, Messages, SysUtils, Classes, Controls, StdCtrls;
type
TStringEvent = procedure(Sender: TObject; var s: String) of object;
TMemoEx = class(TMemo)
private
FOnBeforePaste: TStringEvent;
FOnAfterPaste: TNotifyEvent;
procedure WMPaste(var Message: TMessage); message WM_PASTE;
protected
public
published
property OnBeforePaste: TStringEvent read FOnBeforePaste write FOnBeforePaste;
property OnAfterPaste: TNotifyEvent read FOnAfterPaste write FOnAfterPaste;
end;
procedure Register;
implementation
procedure Register;
begin
RegisterComponents('Andreas Nordlund', [TMemoEx]);
end;
{ TMemoEx }
procedure TMemoEx.WMPaste(var Message: TMessage);
var
strClpText: String;
begin
// Check if the OnBeforePaste event is assigned and check if the clipboard contains plain text.
if Assigned(FOnBeforePaste) and Clipboard.HasFormat(CF_TEXT) then
begin
// Save the clipboard text into a local variable
strClpText := ClipBoard.AsText;
// Fire the OnBeforePaste event
FOnBeforePaste(self, strClpText);
// Clear the clipboard and replace it with the new text
Clipboard.Clear;
Clipboard.AsText := strClpText;
end;
// Perform the actual paste
inherited;
// if the OnAfterPaste event is assigned, fire it.
if Assigned(FOnAfterPaste) then
FOnAfterPaste(self);
end;
end.
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