Adding Messages

TTMSFNCChat stores messages in the ChatMessages collection. Messages can be added programmatically or typed by the user via the built-in message field.

The built-in message field

Set ShowMessageField := True to show a TMemo input and a send button at the bottom:

TMSFNCChat1.ShowMessageField := True;

When the user presses the send button or Enter, a new right-aligned message is added. Use OnBeforeSendMessage to validate or modify the text before it is added:

procedure TForm1.TMSFNCChat1BeforeSendMessage(Sender: TObject;
  var AText: string; var AAllow: Boolean);
begin
  if Trim(AText) = '' then
    AAllow := False;
end;

Adding messages in code

// Add messages via collection
procedure TForm1.Button1Click(Sender: TObject);
var
  itm: TTMSFNCChatItem;
begin
  itm := TMSFNCChat1.ChatMessages.Add;
  itm.Text            := 'How was your day?';
  itm.Title           := 'Mom';
  itm.Fill.Color      := gcGray;
  itm.MessageLocation := cmlLeft;
end;

// Add messages via helper functions
itm := TMSFNCChat1.AddMessage('Hello!', cmlRight);                    // right-aligned
itm := TMSFNCChat1.AddMessage('Hi there!', 'Alice', cmlLeft);         // with title

// Add an image
TMSFNCChat1.AddImage('C:\Photos\photo.jpg');
TMSFNCChat1.AddImage('C:\Photos\photo.jpg', 'Look at this!', cmlLeft);
// With named image in BitmapContainer:
TMSFNCChat1.AddImageWithName('C:\Photos\photo.jpg', 'my-photo');

// Add a file link
TMSFNCChat1.AddFile('file://C:\Reports\report.pdf', 'Monthly Report', 'Attached');

// Clear all messages
TMSFNCChat1.Clear;

// Scroll to a specific item
TMSFNCChat1.ScrollToItem(TMSFNCChat1.ChatMessages.Count - 1);

// Show the message input field at the bottom
TMSFNCChat1.ShowMessageField := True;

// Intercept the send button
procedure TForm1.TMSFNCChat1BeforeSendMessage(Sender: TObject;
  var AText: string; var AAllow: Boolean);
begin
  if Trim(AText) = '' then
    AAllow := False;  // block empty messages
end;

TTMSFNCChat showing left and right message bubbles

Via ChatMessages collection

var itm: TTMSFNCChatItem;
begin
  itm := TMSFNCChat1.ChatMessages.Add;
  itm.Text            := 'How was your day?';
  itm.Title           := 'Mom';
  itm.Fill.Color      := gcGray;
  itm.MessageLocation := cmlLeft;  // cmlLeft or cmlRight
end;

Via AddMessage helpers

TMSFNCChat1.AddMessage('Hello!');                         // right-aligned
TMSFNCChat1.AddMessage('Hi there!', 'Alice', cmlLeft);    // with title, left-aligned

DefaultLeftItem and DefaultRightItem provide the appearance template applied to messages added via AddMessage.

Adding images

// From file path
TMSFNCChat1.AddImage('C:\Photos\photo.jpg');
TMSFNCChat1.AddImage('C:\Photos\photo.jpg', 'Look at this!', cmlLeft);

// With a named key for BitmapContainer storage
TMSFNCChat1.AddImageWithName('C:\Photos\photo.jpg', 'photo-key');

Assign a TTMSFNCBitmapContainer to BitmapContainer and set AddImagesToBitmapContainer := True so images are stored by name rather than embedded as base64 (which can slow down rendering with many images).

Note

On the WEB platform without a BitmapContainer, pass a base64-encoded data URI as the image path.

Adding file links

TMSFNCChat1.AddFile('file://C:\Reports\report.pdf', 'Monthly Report', 'Attached');

The first parameter is the URL opened on click; the second is the display name.

Drag and drop

TTMSFNCChat detects files dragged over the message area. Handle OnFileDragOver to allow the drop, then read the dropped files in OnFileDrop:

procedure TForm1.TMSFNCChat1FileDragOver(Sender: TObject;
  AFileList: TStringList; var AAllow: Boolean);
begin
  AAllow := True;
end;

procedure TForm1.TMSFNCChat1FileDrop(Sender: TObject; AFileList: TStringList);
var
  i: Integer;
begin
  for i := 0 to AFileList.Count - 1 do
    TMSFNCChat1.AddFile('file://' + AFileList[i], ExtractFileName(AFileList[i]));
end;

Reload (pull-to-refresh)

TMSFNCChat1.Reload.Enabled := True;

Dragging down on the chat list starts a reload animation and fires OnStartReload. When your background fetch is done, call StopReload:

procedure TForm1.TMSFNCChat1StartReload(Sender: TObject);
begin
  TThread.CreateAnonymousThread(procedure
  begin
    // load older messages...
    TThread.Synchronize(nil, procedure
    begin
      TMSFNCChat1.StopReload;
    end);
  end).Start;
end;

Combining drag-and-drop, validation, and reload

This pattern connects file drag-and-drop, send validation, and pull-to-refresh in one form:

procedure TForm1.TMSFNCChat1BeforeSendMessage(Sender: TObject;
  var AText: string; var AAllow: Boolean);
begin
  AAllow := Trim(AText) <> '';
end;

procedure TForm1.TMSFNCChat1FileDrop(Sender: TObject; AFileList: TStringList);
var
  i: Integer;
begin
  for i := 0 to AFileList.Count - 1 do
    TMSFNCChat1.AddFile('file://' + AFileList[i], ExtractFileName(AFileList[i]));
end;

procedure TForm1.TMSFNCChat1StartReload(Sender: TObject);
begin
  TThread.CreateAnonymousThread(procedure
  begin
    TThread.Synchronize(nil, procedure begin TMSFNCChat1.StopReload; end);
  end).Start;
end;

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