Added class PrintTransport to simplify the usage of a print transport add-on.

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@6367 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/print/PrintTransport.h

@@ -0,0 +1,61 @@
+/*
+
+PrintTransport
+
+Copyright (c) 2004 OpenBeOS. 
+
+Authors:
+	Michael Pfeiffer
+	Philippe Houdoin
+	
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+
+*/
+
+#ifndef PRINT_TRANSPORT_H
+#define PRINT_TRANSPORT_H
+
+#include <image.h>
+#include <DataIO.h>
+#include <Node.h>
+#include <Message.h>
+
+// The class PrintTransport is intended to be used by
+// a printer driver.
+class PrintTransport
+{
+public:
+	PrintTransport();
+	~PrintTransport();
+
+	// opens the transport add-on associated with the printerFolder
+	status_t Open(BNode* printerFolder);
+	// returns the output stream created by the transport add-on
+	BDataIO* GetDataIO();
+	// returns false if the user has canceled the save to file dialog
+	// of the "Print To File" transport add-on.
+	bool IsPrintToFileCanceled() const;
+	
+private:	
+	BDataIO*   fDataIO;
+	image_id   fAddOnID;
+	void       (*fExitProc)(void);		
+};
+
+#endif PRINT_TRANSPORT_H

src/add-ons/print/shared/Jamfile

@@ -8,6 +8,7 @@ StaticLibrary
 	PicturePrinter.cpp
 	PrintJobReader.cpp
 	PictureIterator.cpp
+	PrintTransport.cpp
 	;
 
 StaticLibrary

src/add-ons/print/shared/PrintTransport.cpp

@@ -0,0 +1,133 @@
+/*
+
+PrintTransport
+
+Copyright (c) 2004 OpenBeOS. 
+
+Authors:
+	Philippe Houdoin
+	Michael Pfeiffer
+	
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+
+*/
+
+#include "PrintTransport.h"
+
+#include <Directory.h>
+#include <File.h>
+#include <FindDirectory.h>
+#include <Path.h>
+#include <String.h>
+
+// implementation of class PrintTransport
+PrintTransport::PrintTransport()
+	: fDataIO(NULL)
+	, fAddOnID(-1)
+	, fExitProc(NULL)
+{
+}
+
+PrintTransport::~PrintTransport()
+{
+	if (fExitProc) {
+		(*fExitProc)();
+		fExitProc = NULL;
+	}
+	
+	if (fAddOnID >= 0) {
+		unload_add_on(fAddOnID);
+		fAddOnID = -1;
+	}
+}
+
+status_t PrintTransport::Open(BNode* printerFolder)
+{
+	// already opened?
+	if (fDataIO != NULL) {
+		return B_ERROR;
+	}
+	
+	// retrieve transport add-on name from printer folder attribute
+	BString transportName;
+	if (printerFolder->ReadAttrString("transport", &transportName) != B_OK) {
+		return B_ERROR;
+	}
+	
+	// try first in user add-ons directory
+	BPath path;
+	find_directory(B_USER_ADDONS_DIRECTORY, &path);
+	path.Append("Print/transport");
+	path.Append(transportName.String());
+	fAddOnID = load_add_on(path.Path());
+	
+	if (fAddOnID < 0) {
+		// on failure try in system add-ons directory
+		find_directory(B_BEOS_ADDONS_DIRECTORY, &path);
+		path.Append("Print/transport");
+		path.Append(transportName.String());
+		fAddOnID = load_add_on(path.Path());
+	}
+
+	if (fAddOnID < 0) {
+		// failed to load transport add-on
+		return B_ERROR;
+	}
+
+	// get init & exit proc
+	BDataIO* (*initProc)(BMessage*);
+	get_image_symbol(fAddOnID, "init_transport", B_SYMBOL_TYPE_TEXT, (void **) &initProc);
+	get_image_symbol(fAddOnID, "exit_transport", B_SYMBOL_TYPE_TEXT, (void **) &fExitProc);
+
+	if (initProc == NULL || fExitProc == NULL) {
+		// transport add-on has not the proper interface
+		return B_ERROR;
+	}
+
+	// now, initialize the transport add-on
+	node_ref   ref;
+	BDirectory dir;
+	
+	printerFolder->GetNodeRef(&ref);
+	dir.SetTo(&ref);
+	
+	if (path.SetTo(&dir, NULL) != B_OK) {
+		return B_ERROR;
+	}
+	
+	// request BDataIO object from transport add-on
+	BMessage input('TRIN');
+	input.AddString("printer_file", path.Path());
+	fDataIO = (*initProc)(&input);
+	return B_OK;
+}
+
+BDataIO*
+PrintTransport::GetDataIO()
+{
+	return fDataIO;
+}
+
+bool PrintTransport::IsPrintToFileCanceled() const
+{
+	// The BeOS "Print To File" transport add-on returns a non-NULL BDataIO *
+	// even after user filepanel cancellation!
+	BFile* file = dynamic_cast<BFile*>(fDataIO);
+	return file != NULL && file->InitCheck() != B_OK;
+}