Application disable resize over Dock
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This article applies to macOS only.
See also: Multiplatform Programming Guide
On macOS it's often needed to disable app window's resize below OS Dock. But Lazarus forms always resize below it. How to disable this resize?
1) Create TForm.OnConstrainedResize handler for your form. Note, it was not "published" in LCL until LCL 1.7. Create it by hands:
TfmMain = class(TForm)
...
private
...
procedure FormConstrainedResize(Sender: TObject; var MinWidth, MinHeight,
MaxWidth, MaxHeight: TConstraintSize);
...
end;
procedure TfmMain.FormCreate(Sender: TObject);
begin
..
Self.OnConstrainedResize:= @FormConstrainedResize;
..
end;
2) Write code in handler to change MaxHeight, value must be workarea height minus current form's Top.
procedure TfmMain.FormConstrainedResize(Sender: TObject; var MinWidth, MinHeight,
MaxWidth, MaxHeight: TConstraintSize);
const
cMinHeight = 200;
var
RWork: TRect;
begin
{$ifndef darwin} exit; {$endif}
RWork:= Screen.PrimaryMonitor.WorkareaRect;
MaxHeight:= Max(cMinHeight, RWork.Bottom - RWork.Top - Top);
end;
3) Note: handler has side effect. On dragging window by its caption, handler is called too, so window will be resized on moving it too low, near the Dock.
