TToolButton.Down property
Indicates whether the button is in the "Down" state, i. e. has it been selected or clicked.
Declaration
property Down: Boolean read FDown write SetDown stored IsCheckedStored default False;Description
Down is a
Boolean property which indicates if the tool
button is in a "pressed" or "down" state. The default value for the property
is
False, and causes the button to be drawn in its normal non-pressed
state. Down is updated when mouse down or up messages are handled for the
button.
The Style property determines whether the Down state is temporary or persistent. When Style contains tsButton, Down is reset to False when a mouse up message occurs for the button. For the tbsCheck style, it is a toggle; mouse down changes the state but mouse up does not automatically release it.
Changing the value for the property causes the control to be redrawn. It may also affect adjacent buttons on the tool bar with their Grouped properties enabled. When Down is enabled for a Grouped button, the other buttons in the group are updated to set their Down states to False.
Set Grouped to True to include the button in a group of adjacent buttons where only one of them can be in the Down state at any given time. The group does not extend beyond separator or divider buttons defined on the tool bar. Use AllowAllUp to control whether all of the buttons in a group can have their Down properties set to False.
Changing the property to True at design-time (or in program code) causes a non-grouped tool button to be drawn in the pressed state regardless of the setting in style. Display logic for the Style is reapplied when mouse messages are handled for the control.
The implementation was modified in LCL version 3.0 to ensure that an endless loop is avoided when Down is changed for grouped button, or when GroupAllUpAllowed is called.
See also
An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.