CFontHolder Class
Implements the stock Font property and encapsulates the functionality of a Windows font object and the IFont interface.
Syntax
class CFontHolder
Members
Public Constructors
| Name | Description |
|---|---|
| CFontHolder::CFontHolder | Constructs a CFontHolder object. |
Public Methods
| Name | Description |
|---|---|
| CFontHolder::GetDisplayString | Retrieves the string displayed in a container's property browser. |
| CFontHolder::GetFontDispatch | Returns the font's IDispatch interface. |
| CFontHolder::GetFontHandle | Returns a handle to a Windows font. |
| CFontHolder::InitializeFont | Initializes a CFontHolder object. |
| CFontHolder::QueryTextMetrics | Retrieves information for the related font. |
| CFontHolder::ReleaseFont | Disconnects the CFontHolder object from the IFont and IFontNotification interfaces. |
| CFontHolder::Select | Selects a font resource into a device context. |
| CFontHolder::SetFont | Connects the CFontHolder object to an IFont interface. |
Public Data Members
| Name | Description |
|---|---|
| CFontHolder::m_pFont | A pointer to the CFontHolder object's IFont interface. |
Remarks
CFontHolder does not have a base class.
Use this class to implement custom font properties for your control. For information on creating such properties, see the article ActiveX Controls: Using Fonts.
Inheritance Hierarchy
CFontHolder
Requirements
Header: afxctl.h
CFontHolder::CFontHolder
Constructs a CFontHolder object.
explicit CFontHolder(LPPROPERTYNOTIFYSINK pNotify);
Parameters
pNotify
Pointer to the font's IPropertyNotifySink interface.
Remarks
You must call InitializeFont to initialize the resulting object before using it.
CFontHolder::GetDisplayString
Retrieves a string that can be displayed in a container's property browser.
BOOL GetDisplayString(CString& strValue);
Parameters
strValue
Reference to the CString that is to hold the display string.
Return Value
Nonzero if the string is successfully retrieved; otherwise 0.
CFontHolder::GetFontDispatch
Call this function to retrieve a pointer to the font's dispatch interface.
LPFONTDISP GetFontDispatch();
Return Value
A pointer to the CFontHolder object's IFontDisp interface. Note that the function that calls GetFontDispatch must call IUnknown::Release on this interface pointer when done with it.
Remarks
Call InitializeFont before calling GetFontDispatch.
CFontHolder::GetFontHandle
Call this function to get a handle to a Windows font.
HFONT GetFontHandle();
HFONT GetFontHandle(
long cyLogical,
long cyHimetric);
Parameters
cyLogical
Height, in logical units, of the rectangle in which the control is drawn.
cyHimetric
Height, in MM_HIMETRIC units, of the control.
Return Value
A handle to the Font object; otherwise NULL.
Remarks
The ratio of cyLogical and cyHimetric is used to calculate the proper display size, in logical units, for the font's point size expressed in MM_HIMETRIC units:
Display size = ( cyLogical / cyHimetric) X font size
The version with no parameters returns a handle to a font sized correctly for the screen.
CFontHolder::InitializeFont
Initializes a CFontHolder object.
void InitializeFont(
const FONTDESC* pFontDesc = NULL,
LPDISPATCH pFontDispAmbient = NULL);
Parameters
pFontDesc
Pointer to a font description structure ( FONTDESC) that specifies the font's characteristics.
pFontDispAmbient
Pointer to the container's ambient Font property.
Remarks
If pFontDispAmbient is not NULL, the CFontHolder object is connected to a clone of the IFont interface used by the container's ambient Font property.
If pFontDispAmbient is NULL, a new Font object is created either from the font description pointed to by pFontDesc or, if pFontDesc is NULL, from a default description.
Call this function after constructing a CFontHolder object.
CFontHolder::m_pFont
A pointer to the CFontHolder object's IFont interface.
LPFONT m_pFont;
CFontHolder::QueryTextMetrics
Retrieves information on the physical font represented by the CFontHolder object.
void QueryTextMetrics(LPTEXTMETRIC lptm);
Parameters
lptm
A pointer to a TEXTMETRIC structure that will receive the information.
CFontHolder::ReleaseFont
This function disconnects the CFontHolder object from its IFont interface.
void ReleaseFont();
CFontHolder::Select
Call this function to select your control's font into the specified device context.
CFont* Select(
CDC* pDC,
long cyLogical,
long cyHimetric);
Parameters
pDC
Device context into which the font is selected.
cyLogical
Height, in logical units, of the rectangle in which the control is drawn.
cyHimetric
Height, in MM_HIMETRIC units, of the control.
Return Value
A pointer to the font that is being replaced.
Remarks
See GetFontHandle for a discussion of the cyLogical and cyHimetric parameters.
CFontHolder::SetFont
Releases any existing font and connects the CFontHolder object to an IFont interface.
void SetFont(LPFONT pNewFont);
Parameters
pNewFont
Pointer to the new IFont interface.