Adding button to Preview

rbuser

Using D7 and RB10
I need to add a button and code to the preview tab in RBuilder. I allow end
users to use the disigner so it has to be available to them when they click
preview tab. The button will serve a function that will export the data to
csv in a certain style not automatically supported by RB.
My question: What is the best way to implement a new button and code on the
preview tab? Does this require creating my own preview screen and will it
work with the Designer?

nicocizik

Hi Bob,

Adding a new button to the preview window can be done by creating a custom
preview plugin. This will work with the designer.

Take a look at the article below on creating a Preview Plugin and see the
ppPreview.pas file for how the toolbar buttons are created for the current
preview. Your plugin would simply need to override the CreateToolbarItems
routine and add a new button similar to the way it is done in the TppPreview
class.

-----------------------------------------
Article: Creating a Preview Plugin
-----------------------------------------

Q: I've followed the tutorials and registered a Preview Form replacement but
that did not affect the TppDesigner's Preview workspace.


A: Do not use the form replacement, but rather, there is a different
architecture built into the preview form that is registered by default.



You will need to register a TppPreview descendent. The class you register
is used to create the preview controls inside the standard print preview
form and the designer preview workspace.


Here is an example of creating a simple custom preview that access the
viewer its been assigned in order to change the page color. You can also do
more advanced operations such as adding and removing buttons and change the
behavior of the preview form. Access the inherited controls via. protected
properties and override the virtual methods in order to customize behavior.

Open ppPreview.pas and view the TppPreview class as a guide to create a
custom preview descendent.


unit MyPreviewPlugin;

interface

uses
ppPreview;

type
TMyPreviewPlugin = class(TppPreview)
public
procedure BeforePreview; override;

end;


implementation

uses
Graphics;


procedure TMyPreviewPlugin.BeforePreview;
begin
inherited BeforePreview;

Viewer.PageColor := clRed;

end;

initialization
TppPreviewPlugIn.Register(TMyPreviewPlugin);

finalization
TppPreviewPlugIn.UnRegister(TMyPreviewPlugin);

end.

--
Regards,

Nico Cizik
Digital Metaphors
http://www.digital-metaphors.com

rbuser

I was able to use your example and make the background red. However, I am
not clear on how to add the button and event code for the extra button. Do
you have another example where a button is actually being addeed?

Thanks,
Bob

nicocizik

Hi Bob,

The article shows the basics of creating a preview plugin however instead of
implementing the BeforePreview event you will need to override the
CreateToolbarItems routine and add the button from there.

I created a rbWiki article and example to show how this should be done.

http://www.digital-metaphors.com/rbWiki/Output/Preview/How_To...Add_a_Button_to_the_Preview

--
Regards,

Nico Cizik
Digital Metaphors
http://www.digital-metaphors.com

rbuser

That was very helpful and easy once I saw your code.
Thanks,
Bob