Draw Pages: XDrawPagesSupplier

Draw and Impress are almost identical in the interfaces that they support. Draw is specifically designed to handle independent graphic objects, whereas Impress is designed for business effects and presentations. The drawing functionality of Draw and Impress is identical, however. The graphic objects are drawn and displayed on "draw pages." By their design, both Draw and Impress support multiple draw pages. The functionality to retrieve a DrawPage object is defined by the com.sun.star.drawing.XDrawPagesSupplier interface. The interface com.sun.star.drawing.XDrawPages defines methods to retrieve, insert, and remove individual pages (see Table 6 ).

Table 6: Object methods defined by the interface XDrawPages.

Object Method	Description
InsertNewBylndex(index)	Create and insert a new draw page or master page.
remove(XDrawPage)	Remove a draw page or master page.
getCount()	Return the number of draw pages.
getByIndex(index)	Return a specific draw page.
hasElements()	Return True if there are documents.

The macro in Listing 10 demonstrates how to iterate through each of the draw pages. Each draw page is exported to a JPG file. The export type is specified by the MediaType property.

Listing 10: Export each graphics page to a JPG.

 oFilter=CreateUnoService("com.sun.star.drawing.GraphicExportFilter") Dim args(1) as new com.sun.star.beans.PropertyValue For i=0 to oDoc.getDrawPages().getcount()-1   oPage = oDoc.getDrawPages().getByIndex(i)   name = oPage.name   oFilter.setSourceDocument(opage)   args(0).Name = "URL"   args(0).Value = "file:///c/"&oPage.name&".JPG"   args(1).Name = "MediaType"   args(1).Value = "image/jpeg"   oFilter.filter(args()) Next 

 

Note  

The index used to access draw pages is zero based. This means that the first draw page is at location 0. If a document contains four draw pages, they are numbered 0 through 3. This is why the For loop in Listing 10 is from 0 To oDoc.getDrawPages().getcount()-1.

The macro in Listing 11 creates a new Impress document and then adds a graphic image to the first draw page. The draw image is sized to retain the aspect ratio.

Listing 11: AddProportionalGraphic is found in the Generic module in this chapter's source code files as SC12.sxw.

 Sub AddProportionalGraphic   Dim oDoc       'Newly created Impress document   Dim oDrawPage  'The draw page that will contain the graphic image   Dim oGraph     'The created graphic image   REM Create an Impress presentation document!   oDoc = StarDesktop.loadComponentFromURL("private:factory/simpress",_                                           "_default", 0, Array())   REM Insert a second draw page if desired,   REM leaving the first draw page untouched!   REM Could use the property DrawPages   REM oDrawPage = oDoc.DrawPages.insertNewByIndex(1)   REM oDrawPage = oDoc.getDrawPages().insertNewByIndex(1)   REM In this case, simply use the first draw page!   oDrawPage = oDoc.getDrawPages().getByIndex(0)   REM Create a graphics object that can be inserted into the document   oGraph = oDoc.createInstance("com.sun.star.drawing.GraphicObjectShape")   REM Set the URL of the image so that it can be added to the document   oGraph.GraphicURL = "http://api.openoffice.org/branding/images/logonew.gif"   oDrawPage.add(oGraph)   REM If I stop here, there will be a very small graphic image in the   REM upper-left corner of the document. This is pretty much useless.   REM Although I could simply size the graphic to the same size as the bitmap   REM size, I choose instead to size this so that it is as large as possible   REM without changing the aspect ratio.   REM Determine the ratio of the height to the width for the image and   REM also for the draw page.   Dim oNewSize As New com.sun.star.awt.Size    'New Image size   Dim oBitmapSize As New com.sun.star.awt.Size 'Bitmap size   Dim dImageRatio As Double     'Ratio of the height to width   Dim dPageRatio As Double      'Ratio of the height to width   oBitmapSize = oGraph.GraphicObjectFillBitmap.GetSize   dImageRatio = CDbl(oBitmapSize.Height) / CDbl(oBitmapSize.Width)   dPageRatio = CDbl(oDrawPage.Height) / CDbl(oDrawPage.Width)   REM Compare the ratios to see which is wider, relatively speaking   If dPageRatio > dImageRatio Then     oNewSize.Width = oDrawPage.Width     oNewSize.Height = CLng(CDbl(oDrawPage.Width) * dImageRatio)   Else     oNewSize.Width = CLng(CDbl(oDrawPage.Height) / dImageRatio)     oNewSize.Height = oDrawPage.Height   End If   REM Center the image on the Impress page!   Dim oPosition as new com.sun.star.awt.Point   oPosition.X = (oDrawPage.Width - oNewSize.Width)/2   oPosition.Y = (oDrawPage.Height - oNewSize.Height)/2   oGraph.SetSize(oNewSize)   oGraph.SetPosition(oPosition) End Sub 

 

As already stated, Impress and Draw documents are very similar in the API that they support. The macro in Listing 12 draws lines in a Draw document (see Figure 6 ).

Figure 6: These lines drawn in a Draw document overlap.

Listing 12: DrawLinesInDrawDocument is found in the Generic module in this chapter's source code files as SC12.sxw.

 Sub DrawLinesInDrawDocument   Dim oDoc       'Newly created Draw document   Dim oDrawPage  'The draw page that will contain the graphics image   Dim oShape     'Shape to insert   REM Create a new Draw document!   oDoc = StarDesktop.loadComponentFromURL("private:factory/sdraw",_                                           "_default", 0, Array())   REM Use the first draw page   oDrawPage = oDoc.getDrawPages().getByIndex(0)   Dim i As Long   Dim oPos as new com.sun.star.awt.Point   Dim oSize as new com.sun.star.awt.Size   Dim dStepSize As Double   dStepSize = CDbl(oDrawPage.Height) / 10   For i = 0 To 10     oShape = oDoc.createInstance("com.sun.star.drawing.LineShape")     oShape.LineColor = rgb(0, 255 - 20 * i, 20 * i)     oShape.LineWidth = 250     oPos.X = 0     oPos.Y = CLng(CDbl(i) * dStepSize)     oShape.setPosition(oPos)     oSize.width = oDrawPage.Width     oSize.height= oDrawPage.Height - 2 * oPos.Y     oShape.setSize(oSize)     oDrawPage.add(oShape)   Next End Sub 

 

Although the primary data in Writer and Calc documents is not drawing data, these documents also contain draw pages. More accurately, each Calc document contains a single draw page for each sheet, and each Writer document contains a single draw page for the entire document. In Writer and Calc documents, the page is like a transparent layer containing drawing data on top of the standard document data.

Writer documents do not support the XDrawPagesSupplier interface, because they only contain a single draw page. They do, however, support the XDrawPageSupplier interface, which defines the single object method getDrawPage().

The macro in Listing 12 uses optional draw page properties-namely height and width. The draw page from a Writer document does not contain these properties. The draw page in a Writer document has other peculiarities , however. For example, adding lines to the draw page-as done in Listing 12-adds them as characters at the cursor position rather than interpreting the positions as specific locations in the document. The macro in Listing 13 draws lines to demonstrate this behavior (also see Figure 7 ).

Figure 7: These lines drawn in a Writer document are treated as characters.

Listing 13: DrawLinesInWriteDocument is found in the Generic module in this chapter's source code files as SC12.sxw.

 Sub DrawLinesInWriteDocument   Dim oDoc       'Newly created Writer document   Dim oDrawPage  'The draw page that will contain the graphics image   Dim oShape     'Shape to insert   REM Create a new Writer document!   oDoc = StarDesktop.loadComponentFromURL("private:factory/swriter",_                                           "_default", 0, Array())   oDrawPage = oDoc.getDrawPage()   Dim i As Long   Dim oSize as new com.sun.star.awt.Size   Dim dStepSize As Double   dStepSize = 800   For i = 0 To 10     oShape = oDoc.createInstance("com.sun.star.drawing.LineShape")     oShape.LineColor = rgb(255, 255 - 20 * i, 20 * i)     oShape.LineWidth = 50     oSize.width = dStepSize - CLng(CDbl(i) * dStepSize / 10)/2     oSize.width = CLng(dStepSize/5 * i - dStepSize)     oSize.height= dStepSize     oShape.setSize(oSize)     oDrawPage.add(oShape)   Next End Sub