SkDocument base for pdf, xps, etc.

include/core/SkDocument.h

+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkDocument_DEFINED
+#define SkDocument_DEFINED
+
+#include "SkRect.h"
+#include "SkRefCnt.h"
+
+class SkCanvas;
+class SkWStream;
+
+class SkDocument : public SkRefCnt {
+public:
+    static SkDocument* CreatePDF(const char filename[]);
+    static SkDocument* CreatePDF(SkWStream*);
+
+    SkCanvas* beginPage(SkScalar width, SkScalar height,
+                        const SkRect* content = NULL);
+    void endPage();
+    void close();
+
+protected:
+    SkDocument(SkWStream*);
+    virtual ~SkDocument();
+
+    virtual SkCanvas* onBeginPage(SkScalar width, SkScalar height,
+                                  const SkRect& content) = 0;
+    virtual void onEndPage() = 0;
+    virtual void onClose(SkWStream*) = 0;
+
+    enum State {
+        kBetweenPages_State,
+        kInPage_State,
+        kClosed_State
+    };
+    State getState() const { return fState; }
+
+private:
+    SkWStream* fStream;
+    State      fState;    
+};
+
+#endif