Problem displaying the Print Preview form when adding a button to the Print Preview toolbar

rbuser

Hi,

I used the example in
http://www.digital-metaphors.com/tips/AddButtonToPreview.zip (obtained
from
http://www.digital-metaphors.com:8080/Output/Preview/How_To...Add_a_Button_to_the_Preview)
to add a button to the Preview toolbar screen.

I modified the button's OnClick method to create a PDF file and
automatically open it (so a kind of "speed button"). Here's the code I
used to achieve that which works for me:


procedure TmyPreview.ehFilebutton_Click(Sender: TObject);
begin

With Viewer.Report do
begin
AllowPrintToFile := True;
ShowPrintDialog := False;
DeviceType := 'PDF';
TextFileName := 'C:\temp\testPDF_' + FormatDateTime('YYYY-MM-DD
HH-NN-SS',now) + '.pdf';
PDFSettings.Author := 'RB Master';
PDFSettings.Title := 'Export to PDF!';
PDFSettings.OpenPDFFile := True;
print;
end;

end;

However, if I do the actions described below, the Print Preview form is
not displayed anymore. Instead the lastly generated PDF is opened in the
default PDF viewer:
1) run the application and click on Button1 which opens the Print
Preview form
2) click on the newly added button which generates a PDF file and opens
it in the default PDF viewer. Close the PDF viewer.
3) close the Print Preview form
4) click on Button1. Now instead of displaying the Print Preview form
(as it happens in step 1 above), the lastly generated PFD is opened in
the default PDF viewer.


I tried to debug and it seems that in step 4 described above no code is
run in the unit myPreview - the call "ppreport1.Print" in Unit1 returns
immediately. I guess I didn't write well the code in the
ehFilebutton_Click method, since I call the report's print method a
second time (so before ppreport1.Print called in Unit1 returns). If
needed I can upload the full testcase.

Am I doing something obviously wrong? The main goal of the newly added
button is to create a PDF from the displayed report without displaying
the Print dialog. If the code above can be fixed or if this
functionality can be achieved in some other way, I'd be very grateful
for any suggestion.

Thanks in advance.

Regards,
Jure

nicocizik

Hi Jure,

When printing from the preview, you need to do something similar to the
Viewer.Print method. This is the routine that gets called when the
Print button is clicked.

The main item you need to take from this routine is to disconnect the
screen device from the report before printing to PDF.

rbuser

Hi Nico,

thanks for the reply.

I'm not sure I understand correctly what you mean with "you need to do
something similar to the Viewer.Print method". Do you mean I have to
override it somehow or to copy its functionality from
\Source\ppViewr.pas and modify it? If I call Viewer.Print I get the
printer print dialog which is exactly what I want to avoid.


I found a post dated 25.5.2006 where you described how to use a
TppPDFDevice, so I guess using the below code I disconnect the screen
device from the report:

-------------8<--------------------

The easiest way to accomplish this is to manually create a TppPDFDevice
object and assign its publisher to the report's publisher before calling
Report.Print. For instance...

uses
ppPDFDevice;


procedure TForm1.Button1Click(Sender: TObject);
var
lPDFDevice: TppPDFDevice;
begin

lPDFDevice := TppPDFDevice.Create(self);

try

lPDFDevice.Publisher := ppReport1.Publisher;
lPDFDevice.FileName := 'c:\myPDF.pdf';
lPDFDevice.PDFSettings.OpenPDFFile := True;

ppReport1.Print;

finally
lPDFDevice.Free;
end;

end;

-------------8<--------------------

If I use the above code it creates the PDF if it's called from the form
where ppReport1 is located. However, if I try to move that code in the
"myPreview" unit so that it would be available also to other reports, id
doesn't create the PDF file anymore. The change I made from the above
code is to replace the reference from "ppReport1" to "Viewer.Report":

procedure TmyPreview.ehFilebutton_Click(Sender: TObject);
var
lPDFDevice: TppPDFDevice;
begin

lPDFDevice := TppPDFDevice.Create(self);

try
lPDFDevice.Publisher := Viewer.Report.Publisher;
lPDFDevice.FileName := 'C:\temp\testPDF_' +
FormatDateTime('YYYY-MM-DD HH-NN-SS',now) + '.pdf';
lPDFDevice.PDFSettings.OpenPDFFile := True;

Viewer.Report.Print;

finally
lPDFDevice.Free;
end;

end;

Is Viewer.Report the reference to the underlying report or am I doing
something wrong?

Regards,
Jure

nicocizik

Sorry if I was unclear. I meant that you will need to mimic the code in
Viewer.Print inside your own button click event.

The code you have below is fine but you are not disconnecting the
ScreenDevice before making the call to Viewer.Report.Print as I
mentioned in my previous post.

procedure TmyPreview.ehFilebutton_Click(Sender: TObject);
var
lPDFDevice: TppPDFDevice;
begin

Viewer.ScreenDevice.Publisher := nil; //Disconnect the screen device

lPDFDevice := TppPDFDevice.Create(self);

try
lPDFDevice.Publisher := Viewer.Report.Publisher;
lPDFDevice.FileName := 'C:\temp\testPDF_' +
FormatDateTime('YYYY-MM-DD HH-NN-SS',now) + '.pdf';
lPDFDevice.PDFSettings.OpenPDFFile := True;

Viewer.Report.Print;

finally
lPDFDevice.Free;
end;

end;

rbuser

Hi Nico,

thanks for the answer. I tried the code you corrected in the previous
post, but unfortunately the PDF file is still not created if the code is
called from the newly added button.

I've created a TForm1.ppReport1BeforePrint event handler with a message
dialog to see if the event is triggered when Viewer.Report.Print is
called and it isn't. If I assume the code in you previous reply is OK,
can you please suggest me what else can I do?

(I assume that mimicking the code in Viewer.Print inside my own button
click event is already performed by the code mentioned in the previous
post?)

Thanks again and regards,
Jure

nicocizik

Hi Jure,

The post from 2006 is applying to a different topic (printing to the
preview and PDF at the same time). When creating your own device, you
will want to call PrintToDevices rather than Print.

rbuser

Hi Nico,

Now it works, thank you very much.

I'd like to ask another question about the toolbar in the Print Preview
form - if you think I should create a new post I'll do it.

I'd like to create a dropdown box with some items (e.g. "Print to PDF",
"Print to XLS", etc.). I've found out that using a TppTBXSubmenuItem
object it's probably possible to achieve that (is there any other way?):

var FDropDown: TppTBXSubmenuItem;
.
.
FDropDown := Toolbar.AddSubMenu;
FDropDown.DropdownCombo := True;
FDropDown.Caption := 'Test dropdown';
.
.

Can you point me to any documentation or any example of how to add items
to the dropdown (probably using FDropDown.Add?), handling events when a
item is clicked, etc.

Regards,
Jure

nardmoseley

There is a TppTBXComboBoxItem defined in ppTBXExtItems.pas. Examples of its
use can be found in the RB source. Open ppDesignToolItemsTBX.pas and search
for TppGradientPalette.CreateControls and you will find code like this...

FStyleDropDown := TppTBXComboBoxItem.Create(nil);
aParent.Add(FStyleDropDown);
FStyleDropDown.DropDownList := True;
FStyleDropDown.Strings.Add('None');
FStyleDropDown.Strings.Add('Horizontal');
FStyleDropDown.Strings.Add('Vertical');
FStyleDropDown.Loaded;
FStyleDropDown.ItemIndex := 0;
FStyleDropDown.OnChange := ehStyle_Change;




Nard Moseley
Digital Metaphors
www.digital-metaphors.com

rbuser

Thanks, it works.

Regards,
Jure