First pieces of SkPDFDevice. Supports:

Matrix transforms.
Rendering bitmaps.
Basic paint parameters.
Rendering rectangles, points, lines, polygons.
Render a paint to the page.

Review URL: http://codereview.appspot.com/2584041

git-svn-id: http://skia.googlecode.com/svn/trunk@614 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/pdf/SkPDFGraphicState.h b/include/pdf/SkPDFGraphicState.h
new file mode 100644
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+++ b/include/pdf/SkPDFGraphicState.h
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+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef SkPDFGraphicState_DEFINED
+#define SkPDFGraphicState_DEFINED
+
+#include "SkPaint.h"
+#include "SkPDFTypes.h"
+#include "SkTemplates.h"
+#include "SkThread.h"
+
+/** \class SkPDFGraphicState
+    SkPaint objects roughly correspond to graphic state dictionaries that can
+    be installed.  So that a given dictionary is only output to the pdf file
+    once, we want to canonicalize them.  Static methods in this class manage
+    a weakly referenced set of SkPDFGraphicState objects: when the last
+    reference to a SkPDFGraphicState is removed, it removes itself from the
+    static set of objects.
+
+*/
+class SkPDFGraphicState : public SkPDFDict {
+public:
+    virtual ~SkPDFGraphicState();
+
+    // Override emitObject and getOutputSize so that we can populate
+    // the dictionary on demand.
+    virtual void emitObject(SkWStream* stream, SkPDFCatalog* catalog,
+                            bool indirect);
+    virtual size_t getOutputSize(SkPDFCatalog* catalog, bool indirect);
+
+    /** Get the graphic state for the passed SkPaint. The reference count of
+     *  the object is incremented and it is the caller's responsibility to
+     *  unreference it when done.  This is needed to accommodate the weak
+     *  reference pattern used when the returned object is new and has no
+     *  other references.
+     *  @param paint  The SkPaint to emulate.
+     */
+    static SkPDFGraphicState* getGraphicStateForPaint(const SkPaint& paint);
+
+private:
+    const SkPaint fPaint;
+    bool fPopulated;
+
+    class GSCanonicalEntry {
+    public:
+        SkPDFGraphicState* fGraphicState;
+        const SkPaint* fPaint;
+
+        bool operator==(const GSCanonicalEntry& b) const;
+        explicit GSCanonicalEntry(SkPDFGraphicState* gs)
+            : fGraphicState(gs),
+              fPaint(&gs->fPaint) {}
+        explicit GSCanonicalEntry(const SkPaint* paint) : fPaint(paint) {}
+    };
+
+    // This should be made a hash table if performance is a problem.
+    static SkTDArray<GSCanonicalEntry>& canonicalPaints();
+    static SkMutex& canonicalPaintsMutex();
+
+    explicit SkPDFGraphicState(const SkPaint& paint);
+
+    void populateDict();
+
+    static int find(const SkPaint& paint);
+};
+
+#endif