Merlin’s Delphi Forge

There are two ways to determine the screen’s height and width.
1) Use the global Screen variable.

uses
Forms;
…
Screen.Height { Screen height in pixels }
Screen.Width { Screen width in pixels }
…
2) Use the Windows API GetSystemMetrics() function. This function can be useful in applications that don’t use the VCL like [...]

When creating components you may want to know when the user changed the font or text. This can be quite easily done using the CM_FONTCHANGED and CM_TEXTCHANGED messages.

TComponent1 = class(TComponent)
…
private
…
procedure CMFontChanged(var Message: TMessage); message CM_FONTCHANGED;
procedure CMTextChanged(var Message: TMessage); message CM_TEXTCHANGED;
…
procedure TComponent1.CMTextChanged(var Message:TMessage);
begin
…
end;
procedure TComponent1.CMFontChanged(var Message:TMessage);
begin
…
end;