Gets emitted when a preview is requested from the native dialog.
The default handler for this signal uses an external viewer application to preview.
To implement a custom print preview, an application must return true from its handler for this signal.
In order to use the provided context
for the preview implementation, it must be given a suitable cairo context with
set_cairo_context.
The custom preview implementation can use is_selected and render_page to find pages which are selected for print and render them. The preview must be finished by calling end_preview (typically in response to the user clicking a close button).
preview |
the PrintOperationPreview for the current operation |
context |
the PrintContext that will be used |
parent |
the Window to use as window parent, or null |
true if the listener wants to take over control of the preview |