Callback - loadImage

Enables you to create a single procedure that loads all the images required for the Ribbon.
In the root node of your customisation there is a callback attribute called loadImage
This is used in conjunction with the 'image' attribute on individual controls.
The callback attribute 'loadImage' is called everytime the Ribbon asks for an image.
This allows you to define one image handler for the entire application.

<customUI xmlns="??" 
 loadImage="OnLoadImage"/> 

<gallery id="??"> 
<item id="??" image="MyImage.jpg"/> 

Public Sub OnLoadImage(ByVal sImageName As String, _ 
                       ByRef Image As Variant) 
   SetImage = LoadPicture("C:\Temp\" & sImageName) 
End Sub 

The <customUI> element's loadImage attribute enables you to specify a callback that can load all images. After you set up this callback procedure, Office calls the callback procedure and passes the string from the image attribute for each control that loads images.
You do not need to implement the getImage callback multiple times, such as one time for each control that requires images.

<customUI xmlns="http://schemas.microsoft.com/office/2006/01/customui" 
  loadImage="GetImage"> 

   <button id="myButton" image="mypic.jpg" /> 

To supply the button's image, Office calls the GetImage function.
It passes the parameter "mypic.jpg" and expects an IPictureDisp object in return.
By using this technique, you can write a single callback procedure that returns all the images your customization needs, without having to write each individual control's getImage callback.
Note that the loadImage callback is not called again when you call the Ribbon's Invalidate method or InvalidateControl method.
For the controls that need to change images dynamically at run time, use the getImage callback.

For example, you could use the code from the following example to provide your customization's images.
The getImage callback method must return a stdole.IPictureDisp type, so you usually need to convert your images to this type.
To perform these conversions, you can use the following PictureConverter class, which inherits from the AxHost class.

Add a DoEvents statement immediately after invalidating the ribbon

Public Sub InitialiseAddInsRibbon(ribbon As IRibbonUI) 
   set mRibbonUI = ribbon 
End Sub 

Public Sub RefreshAddInsRibbon 
   mRibbonUI.Invalidate 
   DoEvents 
End Sub 

Use a single procedure for similar callbacks
Button_getVisible - handles all visibility callbacks then use a select-case

Always refer to a controls ID, never the Tag
2007 - you can change the visibility of a separator at runtime
custom icon sizes (32/16) generates blank error messages

Sub GetImage(Control As IRibbonControl, ByRef image) 
Select Case Control.ID 
Case "gallery1" 
image = "ContentControlBuildingBlockGallery" 
Case "gallery2" 
Set image = LoadImage("CustomeImage" ) 
Case Else 
'Do Nothing
End Select 
End Sub 

Private Type GUID 
Data1 As Long 
Data2 As Integer 
Data3 As Integer 
Data4(0 To 7) As Byte 
End Type 

Private Type PICTDESC 
Size As Long 
Type As Long 
hPic As Long 
hPal As Long 
End Type 

Private Type GdiplusStartupInput 
GdiplusVersion As Long 
DebugEventCallback As Long 
SuppressBackgroundThread As Long 
SuppressExternalCodecs As Long 
End Type 

Private Declare Function GdiplusStartup Lib "GDIPlus" (token As Long, _ 
inputbuf As GdiplusStartupInput, Optional ByVal outputbuf As Long = 0) 
As Long 
Private Declare Function GdipCreateBitmapFromFile Lib "GDIPlus" ( _ 
ByVal filename As Long, bitmap As Long) As Long 
Private Declare Function GdipCreateHBITMAPFromBitmap Lib "GDIPlus" ( _ 
ByVal bitmap As Long, _ 
hbmReturn As Long, _ 
ByVal background As Long) As Long 
Private Declare Function GdipDisposeImage Lib "GDIPlus" ( _ 
ByVal image As Long) As Long 
Private Declare Function GdiplusShutdown Lib "GDIPlus" ( _ 
ByVal token As Long) As Long 
Private Declare Function OleCreatePictureIndirect Lib "olepro32.dll" ( _ 
PicDesc As PICTDESC, _ 
RefIID As GUID, _ 
ByVal fPictureOwnsHandle As Long, _ 
IPic As IPicture) As Long 

Public Function LoadImage(ByVal strFName As String) As IPicture 
Dim uGdiInput As GdiplusStartupInput 
Dim hGdiPlus As Long 
Dim hGdiImage As Long 
Dim hBitmap As Long 

uGdiInput.GdiplusVersion = 1 

If GdiplusStartup(hGdiPlus, uGdiInput) = 0 Then 
If GdipCreateBitmapFromFile(StrPtr(strFName), hGdiImage) = 0 Then 
GdipCreateHBITMAPFromBitmap hGdiImage, hBitmap, 0 
Set LoadImage = ConvertToIPicture(hBitmap) 
GdipDisposeImage hGdiImage 
End If 
GdiplusShutdown hGdiPlus 
End If 

End Function 

Public Function ConvertToIPicture(ByVal hPic As Long) As IPicture 

Dim uPicInfo As PICTDESC 
Dim IID_IDispatch As GUID 
Dim IPic As IPicture 

Const PICTYPE_BITMAP = 1 

With IID_IDispatch 
.Data1 = &H7BF80980 
.Data2 = &HBF32 
.Data3 = &H101A 
.Data4(0) = &H8B 
.Data4(1) = &HBB 
.Data4(2) = &H0 
.Data4(3) = &HAA 
.Data4(4) = &H0 
.Data4(5) = &H30 
.Data4(6) = &HC 
.Data4(7) = &HAB 
End With 

With uPicInfo 
.Size = Len(uPicInfo) 
.Type = PICTYPE_BITMAP 
.hPic = hPic 
.hPal = 0 
End With 

OleCreatePictureIndirect uPicInfo, IID_IDispatch, True, IPic 

Set ConvertToIPicture = IPic 
End Function