TCustomTreeView.WMHScroll procedure

Member of TCustomTreeViewprotectedIn unit ComCtrls

Handles the LM_HSCROLL message for the control.

Declaration

pascal

procedure WMHScroll(var Msg: TLMScroll); message

Arguments

Msg

Window message handled in the method.

Description

WMHScroll ensures that the ScrollLeft property is updated to apply the horizontal scroll code passed in the Msg argument. The following scroll codes are handled in the method:

SB_LEFT: Sets ScrolledLeft to 0.
SB_RIGHT: Sets ScrolledLeft to its largest value for the visible control area.
SB_LINERIGHT: Increments ScrolledLeft by one-half of the default ItemHeight for the control.
SB_LINELEFT: Decrements ScrolledLeft by one-half of the default ItemHeight for the control.
SB_PAGERIGHT: Increments ScrolledLeft by one page of lines.
SB_PAGELEFT: Decrements ScrolleLeft by one page of lines.
SB_THUMBPOSITION, SB_THUMBTRACK: Sets ScrolledLeft to the current scroll bar position in Msg.
SB_ENDSCROLL: Ends scroll bar message handling.

An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.