GetControlClassDefaultSize is a TSize class function used to get the default size for new instances of the class. GetControlClassDefaultSize stores the Width and Height using the CX and CY members in the TSize value. The default value in both CX and CY is 90 pixels.

GetControlClassDefaultSize is called from the Create constructor.

Create is the constructor for the class instance. Create calls the inherited constructor using TheOwner as the owner of the component.

Create calls the GetControlClassDefaultSize class method to get the default height and width values used in instances of the class type, and calls SetBounds to apply the values. Create sets the default values for the following properties:

ControlStyle

Removes the value csAcceptsControls in the property

SplitterType

pstHorizontal

Cursor

crHSplit

Position

45

Create calls the CreateSides method when csDesigning is not in the ComponentState property. CreateSides ensures both TPairSplitterSide instances are created (and parented) in the Sides property.

Destroy is the destructor for the class instance. Destroy ensures that the class instances in Sides are not created (or re-created), and calls the inherited destructor.

CreateWnd is an overridden procedure used to create the window handle for the control. CreateWnd calls CreateSides to ensure both TPairSplitterSide instances are created (and parented) in the Sides property. CreateWnd calls the inherited CreateWnd method.

UpdatePosition is a procedure used to update the value in the Position property. UpdatePosition calls the SetPosition method in the WidgetSetClass to recalculate the current relative position for the splitter control. UpdatePosition stores the value in the Position property.

UpdatePosition is called when the value for the Position property is read.

CreateSides is a procedure used to create missing values in the Sides property. CreateSides ensures that both TPairSplitterSide instances used in the component have been created (and parented).

No actions are performed in the method when component streaming has not been completed, or when the component is freed.

CreateSides is called from the Create, CreateWnd, and Loaded methods.

Loaded is an overridden procedure which performs actions needed when the component has been loaded using the LCL component streaming mechanism. Loaded calls the inherited Loaded method.

Loaded calls the CreateSides method to ensure that both values in the Sides property have been created. Loaded updates the value in Position if the handle for the control has been allocated.

ChildClassAllowed is an overridden Boolean function used to determine if the specified class is inherited from a specific ancestor class. ChildClassAllowed calls the ChildClass.InheritsFrom method. The return value is True when it is derived from the TPairSplitterSide or TSplitter classes.

The default value for the property is crHSplit in TCustomPairSplitter.

Sides is a read-only indexed TPairSplitterSide property which provides access to the adjacent children resized using the Splitter in the component. Sides always has 2 elements in the array (in the range 0..1). If Index contains an invalid value, an exception is raised.

Each control in Sides behaves like a TPanel component with a reference to the TPairSplitter that owns the control. They provide a custom Paint method and WMPaint message handling. Some of their properties have altered visibility; for example, Align and Anchors are private, Top and Left are public.

SplitterType is a TPairSplitterType property which specifies the orientation for the splitter in the component. The values in TPairSplitterType dictate the splitter orientation relative to the adjacent children in Sides. Setting a new value in the SplitterType property causes the value in the Cursor property to be changed to match the selected orientation. For example:

pstHorizontal

Splitter is oriented to size adjacent children horizontally. Cursor is set to crHSplit. (Default value)

pstVertical

Splitter is oriented to size adjacent children vertically. Cursor is set to crVSplit.

Position is an Integer property that indicates the position for the splitter relative to its orientation. Reading the value in splitter causes the UpdatePosition method to be called to recalculate the current position for the Splitter. Position can be set at design-time, or changed at run-time by dragging the grab bar for the splitter. The value in Position affects the sizing of the adjacent child controls in Sides.

When SplitterType contains pstHorizontal, the value in Position is used as the Width for the child control in Sides[0]. The remaining Width in the component (less the 5 pixels used for the Splitter) is set as the Width for the child control in Sides[1].

When SplitterType contains pstVertical, the value in Position is used as the Height for the child control in Sides[0]. The remaining Height in the component (less the 5 pixels used for the Splitter) is set as the Height for the child control in Sides[1].

Implements the TPairSplitter component. TPairSplitter is a component with two TPairSplitterSide children. Both child components can contain other components. The children are separated by a splitter which can be dragged by the user to resize the adjacent children.