How to restrict minimum form's width in FireMonkey?

Question

How do I restrict a minimum form's width in FireMonkey? It used to be so easy in VCL - it just had Max and Min constraints in forms properties.

Answer 1

Just found out TForm has a Constraints property in Delphi 11.

Works perfectly for me without flickering.

Answer 2

Below is an updated version to Sunec's answer, to get rid of flickering.

According to MSDN Mouse_Event has been superseded and SendInput should be used instead: https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-mouse_event

uses WinApi.Windows;

procedure TForm1.FormResize(Sender: TObject);
var
  LInput: TInput;
begin
  if ClientHeight < MIN_HEIGHT then
  begin
    ClientHeight := MIN_HEIGHT;
    FillMemory(@LInput, SizeOf(LInput), 0);
    LInput.Itype := INPUT_MOUSE;
    LInput.mi.dwFlags := MOUSEEVENTF_ABSOLUTE or MOUSEEVENTF_LEFTUP;
    SendInput(1, LInput, SizeOf(LInput));
  end;
  if ClientWidth < MIN_WIDTH then
  begin
    ClientWidth := MIN_WIDTH;
    FillMemory(@LInput, SizeOf(LInput), 0);
    LInput.Itype := INPUT_MOUSE;
    LInput.mi.dwFlags := MOUSEEVENTF_ABSOLUTE or MOUSEEVENTF_LEFTUP;
    SendInput(1, LInput, SizeOf(LInput));
  end;
end;

Answer 3

LaKraven, simulate a mouseUp event to get rid of that flickering.

if (Width > maxWidth) then
begin
  Width := maxWidth;
  Mouse_Event(MOUSEEVENTF_ABSOLUTE or MOUSEEVENTF_LEFTUP, 0, 0, 0, 0);
end;

Answer 4

Place this on the form's "OnResize" event, replace the values as appropriate. Granted, not the best solution in the world, but it'll get you by until the properties are reintroduced!

procedure TForm1.FormResize(Sender: TObject);
begin
  if Width < 400 then
    Width := 400;
  if Height < 400 then
    Height := 400;
end;

The above code is easy enough to change for any combination of maximums or minimums, so have fun!

Answer 5

Additionally for LaKraven's answer about FormResize based solution, use ClientWidth and ClientHeight instead of Width and Height to prevent stretching of the form.

procedure TForm1.FormResize(Sender: TObject);
begin
    if ClientWidth < 400 then
        ClientWidth := 400;
    if ClientHeight < 400 then
        ClientHeight := 400;
end;