ITextSelection::HomeKey method (tom.h)

Article
10/05/2021

Generalizes the functionality of the Home key.

Syntax

HRESULT HomeKey(
  long Unit,
  long Extend,
  long *pDelta
);

Parameters

Unit

Type: long

Unit to use in the Home key operation. It can take on one of the following values.

Value	Meaning
tomLine	Depending on Extend, it moves either the insertion point or the active end to the beginning of the first line in the selection. This is the default.
tomStory	Depending on Extend, it moves either the insertion point or the active end to the beginning of the first line in the story.
tomColumn	Depending on Extend, it moves either the insertion point or the active end to the beginning of the first column in the selection. This is available only if the TOM engine supports tables.
tomRow	Depending on Extend, it moves either the insertion point or the active end to the beginning of the first row in the selection. This is available only if the TOM engine supports tables.

Extend

Type: long

Flag that indicates how to change the selection. If Extend is zero (or tomMove), the method collapses the selection to an insertion point. If Extend is 1 (or tomExtend), the method moves the active end and leaves the other end alone. The default value is zero.

pDelta

Type: long*

Pointer to a variable that receives the count of characters that the insertion point or the active end is moved. This parameter can be null.

Return value

Type: HRESULT

The method returns an HRESULT value. If the method succeeds, it returns S_OK. If the method fails, it returns one of the following error codes. For more information about COM error codes, see Error Handling in COM.

Return code	Description
E_INVALIDARG	Unit is neither tomLine nor tomStory.
S_FALSE	Failure for some other reason.

Remarks

The ITextSelection::HomeKey and ITextSelection::EndKey methods are used to mimic the standard Home/End key behavior.

tomLine mimics the Home or End key behavior without the Ctrl key pressed, while tomStory mimics the behavior with the Ctrl key pressed. Similarly, tomMove mimics the Home or End key behavior without the Shift key pressed, while tomExtend mimics the behavior with the Shift key pressed. So HomeKey(tomStory) converts the selection into an insertion point at the beginning of the associated story, while HomeKey(tomStory, tomExtend) moves the active end of the selection to the beginning of the story and leaves the other end where it was.

The HomeKey and EndKey methods are logical methods like the Move methods, rather than directional methods. Thus, they depend on the language that is involved. For example, in Arabic text, HomeKey moves to the right end of a line, whereas in English text, it moves to the left. Thus, HomeKey and EndKey methods are different than the ITextSelection::MoveLeft and ITextSelection::MoveRight methods. Also, note that the HomeKey method is quite different from the Start property, which is the cp at the beginning of the selection. HomeKey and EndKey also differ from the StartOf and EndOf methods in that they extend from the active end, whereas StartOf extends from Start and EndOf extends from End.

Requirements

Requirement	Value
Minimum supported client	Windows Vista [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
Target Platform	Windows
Header	tom.h
DLL	Msftedit.dll