Core Concepts

TFrameStand and TFormStand share their whole engine, implemented in the SubjectStand unit. This page describes the moving parts; the names are the ones you find in the code.

Subject

The subject is the object you want to show: a TFrame descendant for TFrameStand, a TForm descendant for TFormStand. In the shared code it is typed as TSubject = TFmxObject.

You give the component a subject in two ways:

Method	Who creates the subject	Who frees it
New<T>(AParent, AStandName)	the component (T.Create(nil), Name cleared)	the component, on Close
Use<T>(AFrame, AParent, AStandName)	you	you: on Close the frame is only removed from the stand

The flag is exposed as FrameIsOwned / FormIsOwned (and SubjectIsOwned) on the info object, and you can change it.

Stand

The stand is the visual layer between the subject and its parent. It is a style item, found by name in the StandBook (a TStyleBook) and cloned for each subject, so the same stand can host many subjects at the same time.

The stand name is resolved in this order:

1. the AStandStyleName argument of New/Use/NewAndShow, when not empty;
2. the DefaultStandName property of the component. Its default value is the class name without the T, lowercased: framestand for TFrameStand, formstand for TFormStand.

If no StandBook is assigned, or it contains no item with that name, TFrameStand creates an empty TLayout with Align = Contents and uses it as stand: the subject is shown as is, with no decoration. This is handy for embedding frames in a layout without any effect.

Whatever the style says, the stand is always aligned with Align = Contents (it covers its parent), and it is kept invisible until Show.

See Designing Stands for how to build them.

Container

The container is the element of the stand whose StyleName is container. The subject is added to it, so you decide with the container's Align, Margins and size where the frame lands inside the stand. If the stand has no container element, the stand itself is the container.

Parent

The parent is the FMX object the stand is added to: any TFmxObject, typically a TLayout, the form, or a control you want to decorate (a TEdit, a TListView, a TImage...). It is resolved in this order:

1. the AParent argument, when assigned;
2. the DefaultParent property;
3. the Owner of the component (the form you dropped it on), when it is a FMX object.

Any TFmxObject works as parent, 3D objects such as a TLayer3D or a TForm3D included. If no parent can be found (the component is owned by a data module, or by nothing), New and Use raise an ESubjectStandError: pass the parent or set DefaultParent.

Info

Every subject handled by the component has an info object: TFrameInfo<T> for frames, TFormInfo<T> for forms, both descending from TSubjectInfo. It is the handle you keep to drive the subject:

var
  LInfo: TFrameInfo<TDetailsFrame>;
begin
  LInfo := FrameStand1.New<TDetailsFrame>(Layout1, 'sidepanel');
  LInfo.Frame.Customer := ACustomer;  // typed access to the frame
  LInfo.Show;
  // later...
  LInfo.HideAndClose;
end;

Its main members:

Member	What it is
Frame / Form	the subject, typed as T
Stand	the clone of the stand (a TControl)
Container	the element the subject was added to
Parent	the object the stand was added to
StandStyleName	the name of the stand used
Status	Initializing, Ready, Showing, Visible, Hiding, Hidden, Closing
IsVisible, Hiding	shortcuts on the state
Show, Hide, HideAndClose, Close	see Lifecycle & Ownership

The component keeps all the infos in FrameInfos (FormInfos), a dictionary keyed by subject, and you can look them up again later:

FrameStand1.FrameInfo(MyFrame);                    // by instance
FrameStand1.FrameInfo<TDetailsFrame>;              // first info whose frame is a TDetailsFrame
FrameStand1.GetFrameInfo<TDetailsFrame>(True);     // the same, created with New<T> if missing
FrameStand1.LastShownFrame;                         // the most recent Show not yet taken back by a Hide

The component

TFrameStand and TFormStand are non-visual components (they descend from TComponent through TSubjectStand). You usually drop one on each form that shows frames, but nothing stops you from having more (one per style of stand, for instance) or from creating them in code.

Their published properties:

Property	Default	Purpose
StandBook		the TStyleBook with the stands
DefaultStandName	framestand / formstand	stand used when none is given
DefaultParent		parent used when none is given (otherwise the owner)
AnimationShow	OnShow*	mask of the animations started on show
AnimationHide	OnHide*	mask of the animations started on hide
CommonActionList		a TActionList for Common Actions
CommonActionPrefix	ca_	prefix that binds a control to an action of CommonActionList
DefaultHideAndCloseDeferTimeMS	100	pause between hide and close in HideAndClose

StyleBook and DefaultStyleName are older names of StandBook and DefaultStandName, kept for compatibility.

The full list of methods is in the reference.