Show hint when component receives focus

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How to show the hint of a TEdit when it receives focus, without the mouse being on top of it? I did not put code because I have not the slightest idea.

    
asked by anonymous 22.05.2015 / 05:43

2 answers

1

Work on the following code in the event OnEnter of the TEdit (s) you want:

Create the required variables: 

var
    Origin : TPoint; // Receberá a origem do Form na tela
    HintWindow : THintWindow; // Objeto Hint do delphi
    Hint : String; // Receberá a Hint do Edit
    EditL, EditT, EditR, EditB : Integer; // Parâmetros do retângulo da Hint

Set the values of the variables: 

Origin := ClientToScreen(Point(0,0)); //Origem do Form na tela
Hint := (Sender as TControl).Hint;  //Atribua a Hint do Edit

Calculate the positions for the Hint rectangle: 

EditL := Origin.X + (Sender as TControl).Left + 20;
EditT := Origin.Y + (Sender as TControl).Top - 12;
EditR := EditL + Length(Hint) * 9; 
EditB := EditT + 18;

Create a new Hint object; show it in the rectangle calculated on the previous line: 

HintWindow := THintWindow.Create(nil);
HintWindow.ActivateHint( Rect(EditL, EditT, EditR, EditB), Hint );

At the moment you want to release Hint just use HintWindow.Free .

I suggest that you release it in the event OnExit of Edit or using a Timer of 5 to 8 seconds for a traditional Windows effect.

    
22.05.2015 / 19:58
1

Another way to do this, which also works on events, is to create your own suggestion window with THintWindow as suggested this article .

  • Define the following variables: 

    FActive: boolean;
FHint: THintWindow;

    Update : Below the Uses clause, set the constant: 

    Uses
//....

Const
  UM_EXITPROC = WM_USER + 42;

  • Use the method below to disable the suggestion window: 

    procedure DesativarSugestao;
begin
  FActive := false;
  if Assigned(FHint) then
    begin
      FHint.ReleaseHandle;
      FHint.Free;
      FHint := nil;
    end;
end;

  • Use the method below to receive right-click and left-mouse click messages: 

    procedure AppMessage(var AMessage: TMsg; var Handled: Boolean);
begin
  if (AMessage.Message = WM_LBUTTONDOWN) or (AMessage.Message = WM_RBUTTONDOWN) then
    if Assigned(FHint) and FHint.Visible then
      DesativarSugestao;
end;

  • Method responsible for displaying the suggestion box: 

    procedure mostrarSugestao(Sender: TObject);
Var
   P: TPoint;
   R: TRect;
   Sugestao: string;
begin
  if Assigned(FHint) and FActive then
     Exit;
  P.X := (Sender As TEdit).Left;
  P.Y := (Sender As TEdit).Top - 24;
  with R do
    begin
      topLeft := ClientToScreen(P);
      Right := Left + 150;
      Bottom := Top + 18;
    end;

  Sugestao := 'A sugestão é...'; // Ou (Sender As TEdit).Text
  FHint := THintWindow.Create(Self);
  FHint.ActivateHint(R, Sugestao);
  FActive := True;
  PostMessage(Handle, UM_EXITPROC, 0, 0);
end;

  • In event OnEnter of Edit do: 

    procedure Edit1Enter(Sender: TObject);
begin
  if not Assigned(FHint) and FActive = False then
    mostrarSugestao(Sender);
end;

  • In event OnExit of Edit do: 

    procedure Edit1Exit(Sender: TObject);
begin
  if Assigned(FHint) and FActive then
    DesativarSugestao;
end;

  • In event OnKeyPress of Edit do: 

    procedure Edit1KeyPress(Sender: TObject; var Key: Char);
begin
  if Assigned(FHint) and FActive then
    DesativarSugestao;
end;

  • In event OnMouseEnter do: 

    procedure Edit1MouseEnter(Sender: TObject);
begin
  if not Assigned(FHint) and FActive = False then
    mostrarSugestao(Sender);
end;

  • In event OnMouseLeave do: 

    procedure Edit1MouseLeave(Sender: TObject);
begin
  if Assigned(FHint) and FActive then
    DesativarSugestao;
end;

  • In event OnClick of Edit do: 

    procedure TForm1.Edit1Click(Sender: TObject);
begin
  if Assigned(FHint) and FActive then
    DesativarSugestao;
end;

  • In event OnCreate of the form do: 

    procedure FormCreate(Sender: TObject);
begin
  Application.OnMessage := AppMessage;
end;

    • The result should look something like this:

        
    22.05.2015 / 21:54
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