In any decently complex form design you will probably have edit controls (edit boxes, drop down lists, radio buttons, check boxes, etc) contained within a parent container control (TPanel, TGroupBox, ...).
Depending on the user interface design of your application you might have groups of container type controls.
In any data aware (database) application you probably have db-aware controls dropped on some container connected to a TDataSource connected to a TDBNavigator.
When you click the "Edit" or "Insert" buttons on the DBNavigator you want the "first" control in the group to receive the input focus - to allow for faster data input.
The FocusFirstEntryControl procedure will set the input focus to the first control in a container that is capable of receiving the focus:
procedure FocusFirstEntryControl(const container : TWinControl) ;
var
index : integer;
begin
for index := 0 to -1 + container.ControlCount do
begin
if container.Controls[index] is TWinControl then
begin
TWinControl(container.Controls[index]).SetFocus;
Break;
end;
end;
end;
Note: the code uses ControlCount and Controls properties of a TWinControl descendant to access all controls that list some control as their Parent property.
The "AS" and "IS" operators are used to check if a control contained in a parent control can receive the focus (and set it).
Here's an example of usage:
begin
//set the input focus to the first
//"editable" control in "GroupBox1"
FocusFirstEntryControl(GroupBox1) ;
end;
Delphi tips navigator:
» Iterating Over a Set type Variable in Delphi - Using For .. In Set_Values
« Implementing "Contains Focus" for Delphi's Container Controls: TPanel, TGroupBox, ...
