Setting up XFRX previewer

Default settings

A new objects-type property has been added to the XFCont, cntXFRXMultipage and frmMPPreviewer classes:

Object oDisplayDefaults has the following properties:

Example:

m.loPreview = CREATEOBJECT("frmMPPreviewer")
m.loPreview.oDisplayDefaults.StartingPage = 2
m.loPreview.oDisplayDefaults.DefaultOutputFileName = "invoice15_09"
m.loPreview.oDisplayDefaults.ZoomFactor = -1
m.loPreview.oDisplayDefaults.PagesPerSheet = "1x1"
m.loPreview.lVFP8=.T. && don't use XFRX#LISTENER
m.loPreview.PreviewXFF(loXFF)
m.loPreview.show(1)

Common methods and properties

Even though you can use different classes to provide the previewing capabilities in your application, all classes share most of the properties and methods you can use to control and customize them.

Controlling multi-tab preview features

Registering an extension handler

The extension handler allows for extending the functionality of the basic classes without need of creating subclasses. All you need is to create a custom class, which implements certain methods. The custom class is registered with the XFRX previewer class (using SetExtensionHandler method) and the previewer calls the extension methods on appropriate events.

Currently supported event methods are:

USE demoreps\invoices ORDER customer
LOCAL m.loSession, m.lnRetval, m.loXFF, m.loPreview, m.loScripts
m.loSession=EVALUATE([xfrx("XFRX#LISTENER")])
m.lnRetVal = m.loSession.SetParams(,,,,,,"XFF") && no name = just in memory
IF m.lnRetVal = 0
   REPORT FORM demoreps\invoices OBJECT m.loSession
   *
   * the XFRX#DRAW object reference is stored in oxfDocument property
   *
   m.loXFF = m.loSession.oxfDocument
   *
   * initialize the previewer 
   *
   SET PATH TO xfrxlib
   SET CLASSLIB TO xfrxlib ADDITIVE 
   m.loPreview = CREATEOBJECT("frmMPPreviewer")
   *
   * setup the extension handler
   *
   m.loPreview.oExtensionHandler = CREATEOBJECT("SampleExtensionHandler")
   m.loPreview.windowtype = 1 
   m.loPreview.iTool = 2 && embedded toolbar
   m.loPreview.PreviewXFF(loXFF)
   m.loPreview.show(1)
ENDIF

DEFINE CLASS SampleExtensionHandler AS CUSTOM

   PROCEDURE KeyPress(m.loXFCont, m.nKeyCode, m.nShiftAltCtrl)
      * hotkey for print P (112-p, 80-P)
      IF INLIST(m.nKeyCode, 112, 80)
         m.loXFCont.Print()
      ENDIF
   ENDPROC
ENDDEFINE 

Showing / hiding left panel (bookmarks)

The left panel behavior is controlled by the iBook property:

Showing / hiding previewer toolbars

There are two toolbars in the previewer control – one is placed at the bottom of the control, the other one is available as a floating toolbar panel, which by default docks at the top of the main window, or, alternatively, as an “embedded toolbar”. All three classes implement iTool and ShowStatus properties that control visibility of the toolbars:

Displaying progress bar 

USE demoreps\invoices ORDER customer
LOCAL m.loSession, m.lnRetval, m.loXFF, m.loPreview, m.loScripts
m.loSession=EVALUATE([xfrx("XFRX#LISTENER")])
m.lnRetVal = m.loSession.SetParams(,,,,,,"XFF") && no name = just in memory
IF m.lnRetVal = 0
   REPORT FORM demoreps\invoices OBJECT m.loSession
   *
   * the XFRX#DRAW object reference is stored in oxfDocument property
   *
   m.loXFF = m.loSession.oxfDocument
   *
   * initialize the previewer 
   *
   SET PATH TO xfrxlib
   SET CLASSLIB TO xfrxlib ADDITIVE 
   m.loPreview = CREATEOBJECT("frmMPPreviewer")
   *
   * setup the extension handler
   *
   m.loPreview.oExtensionHandler = CREATEOBJECT("SampleExtensionHandler")
   m.loPreview.oprogress=createobject("progress")
   m.loPreview.PreviewXFF(loXFF)
   m.loPreview.show(1)
ENDIF

DEFINE CLASS progress AS CUSTOM
   PROCEURE updateProgress
      LPARAM m.ta,m.tb, m.tc
      WAIT WINDOW NOWAIT "Page #: "+ALLT(STR(m.tb))+" Report #: "+ALLT(STR(m.ta))+" ("+ALLT(STR(m.tc))+"%)"
   ENDPROC
ENDDEF

Using frmMPPreviewer class

This class serves as a standalone (fullscreen) previewer window. All you need to do to make it work is to pass it a reference to the XFF file to preview, using the previewXFF method, as described in Controlling multi-tab preview features paragraph above. (If you are not sure how to create a XFF file reference, please read chapters 17.0: Initializing the XFRX#DRAW class instance and 16.3: Creating temporary XFF files). Here is a very simple “Hello World” example:

LOCAL m.loPreview
SET CLASSLIB TO XFRXLIB.VCX ADDITIVE 
m.loPreview = CREATEOBJECT("frmMPPreviewer") && create the previewer object
m.loPreview.previewXFF(m.loXFF)              && loXFF is XFF file reference
m.loPreview.show(1)                          && show the form as modal

Using cntXFRXMultiPage class

1. Add an instance of cntXFRXMultiPage class (of XFRXLIB.VCX) into your form. Adjust the size of the cntXFRXMultiPage class object container as you need. The previewer, including the status bar, icons and scroll bars will be displayed in the container. If you resize the container in runtime, its content is automatically adjusted.

2. When the form is about to be released, the cntXFRXMultiPage class instance needs to do some cleanup. To enable that please call the class instance’s clearLink() method from form’s destroy method:

   PROCEDURE Destroy
      Thisform.cntXFRX.clearLink()
   ENDPROC

3. When running the form, make sure the XFRXLIB.VCX class library is referenced in SET CLASSLIB command:

   SET CLASSLIB TO XFRXLIB.VCX ADDITIVE

4. Call the PreviewXFF method to preview a XFF file, as described in Controlling multi-tab preview features paragraph above.
5. By default, cntXFRXMultiPage is using an instance of the XFCont class for each page. Should you like to make it use a different class (eg. a subclass of XFCont) put the class name to the ClassPreviewPage property of the cntXFRXMultiPage instance.

Using XFCont class

1. Add an instance of XFCONT class (of XFRXLIB.VCX) into your form. Adjust the size of the XFCONT class container as you need. The previewer, including the status bar, icons and scroll bars will be displayed in the container. If you resize the container in runtime, its content is automatically adjusted.

2. When the form is about to be released, the XFCONT class instance needs to do some cleanup. To enable that please call the XFCont class instance’s clearLink() method from form’s destroy method:

   PROCEDURE

   PROCEDURE Destroy Thisform.cntXFRX.clearLink() ENDPROC

3. When running the form, make sure the XFRXLIB.VCX class library is referenced in SET CLASSLIB command:

   SET CLASSLIB TO XFRXLIB.VCX ADDITIVE

VFP 8.0 approach

In VFP 8.0, there are two options how to preview report in the previewer. The options differ in the calling mechanism, although internally they both work exactly the same.

Generating the “CNT” output type

The approach is using the standard syntax of calling XFRX, without explicitly using the XFRX#DRAW class (although it is used in the background). You cannot open an existing XFF file with this approach – you always need to run a report that will be previewed.

1. Do not send anything as the output file name

2. Use “CNT” as the output type parameter in the SetParams method call

3. Call Reset method of the previewer container class

4. Call SetOtherParams method of the XFRXSession class instance with the reference of XFCont instance as a parameter

Example:

LOCAL m.loSession, m.lnRetval 
loSession= xfrx("XFRX#INIT") 
m.lnRetVal = m.loSession.SetParams(,,,,,,"CNT") 
IF m.lnRetVal = 0 
   * * we are assuming the XFCont container is 
   * available as thisform.cntXFRX 
   * Thisform.cntXFRX.reset() 
   m.loSession.setotherparams(Thisform.cntXFRX) 
   m.loSession.ProcessReport("report") 
   m.loSession.finalize() 
ENDIF

Using the XFRX#DRAW class

The advantage of this method is that you can preview an existing XFF file – the XFF file is opened and “converted” to “CNT” output type via the TransformReport method:

Example:

LOCAL m.loSession 
m.loSession= xfrx("XFRX#INIT") 
Thisform.oReport = xfrx("XFRX#DRAW") 
IF Thisform.oReport.openDocument("file.xff") 
   Thisform.cntXFRX.reset() 
   m.lnRetVal = m.loSession.SetParams(,,,,,,"CNT") 
   IF m.lnRetVal = 0 
      m.loSession.setOtherParams(Thisform.cntXFRX) 
      m.loSession.TransformReport(Thisform.oReport) 
   ENDIF 
ENDIF

VFP 9.0 Approach

In VFP 9.0 the logic is the same, just the syntax is a little bit different – the reference to the XFCont object is copied to XFRXPreviewer property of the XFRXListener class instance and then previewReport method with the XFRX#DRAW reference as parameter is called:

LOCAL m.loSession
m.loSession= xfrx("XFRX#LISTENER")
Thisform.oReport = xfrx("XFRX#DRAW")
IF Thisform.oReport.openDocument("file.xff")
   Thisform.cntXFRX.reset()
   m.loSession.XFRXPreviewer = Thisform.cntXFRX
   m.loSession.previewReport(Thisform.oReport)
ENDIF

Hyperlink decoration

A new property has been added to the XFCont, cntXFRXMultipage and frmMPPreviewer classes: UnderlineHyperlinksOnPrint. You can use the following values:
0 - no decoration for hyperlinks
1 - display "normal" hyperlinks in blue, but do not decorate custom event hyperlinks (green)
2 - (default value) decorate both blue and green hyperlinks

To support this in the print output, the PrintDocument method of the XFRX#DRAW class has a new parameter, tnUnderlineHyperlinksOnPrint, with the same values and logic.

Custom buttons

This feature is implemented using the extension handler mechanism: A new method is now supported - ToolbarOnInit, which is invoked at the time the toolbar is initialized. In this method the extension handler can add new buttons to the previewer and their click events can be bound with other methods in the extension handler. A new property is now supported, too - oPreviewContainer. If it is available, the previewer will automatically fill it with the XFCont object reference for easier access to the previewer properties in the custom buttons click event methods.

Example:

USE demoreps\sales
LOCAL m.loSession, m.lnRetval, m.loXFF, m.loPreview, m.loScripts
m.loSession=EVALUATE([xfrx("XFRX#LISTENER")])
m.lnRetVal = m.loSession.SetParams(,,,,,,"XFF") && no name = just in memory
IF m.lnRetVal = 0
   REPORT FORM demoreps\sales OBJECT m.loSession
   *
   * the XFRX#DRAW object reference is stored in oxfDocument property
   *
   m.loXFF = m.loSession.oxfDocument
   *
   * initialize the previewer
   *
   SET PATH TO xfrxlib
   SET CLASSLIB TO xfrxlib ADDITIVE
   m.loPreview = CREATEOBJECT("frmMPPreviewer")
   *
   * setup the extension handler
   *
   m.loPreview.oExtensionHandler = CREATEOBJECT("SampleExtensionHandler")
   m.loPreview.windowtype = 1
   m.loPreview.iTool = 2 && embedded toolbar
   *m.loPreview.iTool = 1 && standard toolbar
   m.loPreview.PreviewXFF(m.loXFF)
   m.loPreview.show(1)
ENDIF
 
DEFINE CLASS SampleExtensionHandler AS CUSTOM
 
   oPreviewContainer = .NULL.
 
   PROCEDURE ToolbarOnInit
      LPARAMETERS m.toToolbar
      LOCAL m.button
      IF m.toToolbar.AddObject("mybutton", "commandbutton")
         BINDEVENT(m.toToolbar.mybutton, "click" , This, "ButtonClicked")                       
         m.toToolbar.mybutton.tabindex = 1
         m.toToolbar.mybutton.Visible = .t.
         IF UPPER(m.totoolbar.BaseClass)!="TOOLBAR"
            m.toToolbar.mybutton.left = m.toToolbar.cmdQuit.left
            m.toToolbar.cmdQuit.left = m.toToolbar.mybutton.left + m.toToolbar.mybutton.width
         ENDIF                           
      ENDIF
   ENDPROC
 
   PROCEDURE ButtonClicked
      LOCAL m.lcString
      m.lcString = "This.oPreviewContainer.Name: "+This.oPreviewContainer.Name+CHR(13)
      m.lcString = m.lcString + "current page: "+TRANSFORM(This.oPreviewContainer.nPageNo)+CHR(13)
      m.lcString = m.lcString + "XFRX#DRAW Object: "+This.oPreviewContainer.oXFRXWriter.Name+CHR(13)
      m.lcString = m.lcString + "Page count: "+TRANSFORM(This.oPreviewContainer.oXFRXWriter.PageCount)+CHR(13)
      WAIT WINDOW m.lcString
   
      *This.oPreviewContainer.oXFRXWriter.PrintDocument(...)
      *This.oPreviewContainer.oXFRXWriter.SavePicture(...)
   ENDPROC

ENDDEFINE