Line breaks in TMemo on a form with Default button

Question

I have a form in an application written using FireMonkey. On that (modal) form there's an OK button for which I have set Default property to True. There's also a memo component. Now if type press enter while typing in the memo, then the form is closed instead of inserting line break into memo.

What I would like to accomplish, is that when enter (or shift+enter or smth like that) is pressed in memo component, then line break is enter. In other components, where you cannot type line breaks, I would still like hitting enter to close the form. The best I have found thus far is adding following code into forms OnCloseQuery action:

if (Focused.GetObject.ClassName = 'TMemo') and (ModalResult = mrOk) then
begin
  CanClose := False;
  Memo := TMemo(Focused.GetObject);
  Memo.InsertAfter(Memo.CaretPosition, sLineBreak, [TInsertOption.ioMoveCaret,
    TInsertOption.ioCanUndo]);
end
else
  CanClose := True;

This works, but there's now there's a small annoying delay after hitting enter and before the line break appears. Also I would like solution, that would be less hacky.

I should also point out, that I also have forms which contain the OK button, but not the memo component, however a memo will be moved to that form at runtime by changing its parent property.

Unhandled

Try Memo.Lines.BeginUpdate; before changing Memo content and Memo.Lines.EndUpdate; after that. – Presley

Emba missed to implement TMemo WantReturns, WantTabs properties :o( I would use an OnIdle Event on the form to check if there is a focused TMemo to set the Default property. But Emba also have no TApplicationEvent for FMX :o( Only TActionList has OnUpdate Event which fired on idle if at least one action is defined and assigned to a control – Malt

In your default button OnClick event, test if the memo is focused and set ModalResult to mrNone if that is the case. – Damar

@LURD The problem is caused by TButton.Default := True so pressing RETURN has no effect on TMemo. If TButton.ModalResult is set, there is no need for an OnClick event – Malt

@SirRufo, you are correct, my mistake. – Damar

@Presley BeginUpdate/EndUpdate was a good idea I failed to try, but unfortunately delay comes from somewhere else (code in OK buttons event handler). – Subsidiary

@LURD I tried your advice and I realized that delay actually was caused by the code in OnClick event handler and by checking the focused item type I can now skip the code that caused the delay if memo is focused. So basically the delay issue is resolved. Thanks! – Subsidiary

That has to be an FMX bug. When the memo has focus, it should consume the ENTER key press. – Mezereum

Answer 1

Set btnOk.Default to False in your memo's OnEnter, and back to True in the memo's OnExit

Catt

It's not always that easy. I have forms where memo is on another form that is embedded into form with the OK button (like in https://mcmap.net/q/160839/-how-embed-a-firemonkey-form-inside-a-control). Therefore sometimes memo has no way of knowing whether there's a button. – Subsidiary

In that case, you could create a descendant of TMemo which searches through its parent's controls for a button with Default set to True, and set it to False in the CMEnter() method, and back to True in CMExit() – Catt