Add SkPDFResourceDict class, refactor existing code

src/pdf/SkPDFResourceDict.h

+

[vandebo (ex-Chrome), 2013/07/10 18:24:31]

nit: remove blank line.  Other files have it because of a copyright update that
inserted it by mistake.

[ducky, 2013/07/10 22:54:34]

Done.

+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+

[vandebo (ex-Chrome), 2013/07/10 18:24:31]

nit: remove extra blank line.

[ducky, 2013/07/10 22:54:34]

Done.

+#ifndef SkPDFResourceDict_DEFINED
+#define SkPDFResourceDict_DEFINED
+
+#include "SkRefCnt.h"

[vandebo (ex-Chrome), 2013/07/10 18:24:31]

omit

[ducky, 2013/07/10 22:54:34]

Done.

+#include "SkPDFTypes.h"
+#include "SkTDArray.h"
+#include "SkTSet.h"
+#include "SkTypes.h"
+
+/** \class SkPDFResourceDict
+
+    A resource dictionary, which maintains the relevant sub-dicts and
+    allows generation of a list of referenced SkPDFObjects inserted with
+    insertResourceAsRef.
+*/
+class SkPDFResourceDict : public SkPDFDict {
+ public:

[vandebo (ex-Chrome), 2013/07/10 18:24:31]

nit: no indent.

[ducky, 2013/07/10 22:54:34]

Done. Not really sure where that came from...

+    SK_DECLARE_INST_COUNT(SkPDFResourceDict)
+
+     enum SkPDFResourceType{
+        kExtGState_ResourceType,
+        kColorSpace_ResourceType,

[vandebo (ex-Chrome), 2013/07/10 18:24:31]

omit, since not used.  A comment with the unused types would be fine.

[ducky, 2013/07/10 22:54:34]

Done.

+        kPattern_ResourceType,
+        kShading_ResourceType,
+        kXObject_ResourceType,
+        kFont_ResourceType,
+        kProperties_ResourceType
+     };
+
+    /** Create a PDF resource dictionary.
+     */
+    SkPDFResourceDict() : SkPDFDict() {};

[vandebo (ex-Chrome), 2013/07/10 18:24:31]

non-POD member variable means that the constructor should be defined in the .cpp
file.

[vandebo (ex-Chrome), 2013/07/10 18:24:31]

Why both a no argument constructor and a constructor with a bool parameter that
when false has the same effect as the no argument constructor?

[ducky, 2013/07/10 22:54:34]

Done.

[ducky, 2013/07/10 22:54:34]

Done. It looked useful at once point in time, but not anymore...

+
+    /** Create a PDF resource dictionary, optionally also creating the full
+     *  set of ProcSet entries for backwards compatibility (as recommended
+     *  by the PDF spec).
+     */
+    SkPDFResourceDict(bool createProcSets);

[vandebo (ex-Chrome), 2013/07/10 18:24:31]

Is this ever set to false?  If not, omit the argument and just always create the
proc set.  Also, constructors with one argument should always have the explicit
keyword.

[ducky, 2013/07/10 22:54:34]

No, it's never set to false. The original idea was to add an explicit argument
so there's less possible confusion about the magic happening with ProcSets
automatically being constructed. I've just moved that into a comment now.

+
+    /** Add the value to the dictionary with the given key.  Refs value.
+     *  The relevant sub-dicts will be automatically generated, and the
+     *  resource will be named by concatenating a type-specific prefix and
+     *  the input key.
+     *  The object will NOT be part of the resource list when requested later.
+     *  @param type  The type of resource being entered.
+     *  @param key   The resource key, should be unique within its type.
+     *  @param value The resource itself.
+     *  @return The value argument is returned.
+     */
+    SkPDFObject* insertResource(SkPDFResourceType type, int key,

[vandebo (ex-Chrome), 2013/07/10 18:24:31]

Not used, omit.

[ducky, 2013/07/10 22:54:34]

It's used by insertResourceAsRef, and it's possible for a resource dict to
directly reference an object (though I don't think Skia does that currently).

[vandebo (ex-Chrome), 2013/07/11 17:50:23]

If we're not using it, don't make it part of the public API.  It's always easier
to add things to a public API than it is to take them away.  You could leave it
as a separate function and just make it private for now.  Or you could inline
the code at the caller.

+                                SkPDFObject* value);
+
+    /** Add the value SkPDFObject as a reference to the resource dictionary
+     *  with the give type and key.
+     *  The relevant sub-dicts will be automatically generated, and the
+     *  resource will be named by concatenating a type-specific prefix and
+     *  the input key.
+     *  This object will be part of the resource list when requested later.
+     *  @param type  The type of resource being entered, like Pattern or ExtGState.
+     *  @param key   The resource key, should be unique within its type.
+     *  @param value The resource itself.
+     *  @return The value argument is returned.
+     */
+    SkPDFObject* insertResourceAsRef(SkPDFResourceType type, int key,
+                                     SkPDFObject* value);
+
+    /**
+     * Gets resources inserted into this dictionary.
+     *
+     * @param knownResourceObjects Set containing currently known resources.
+     *     Resources in the dict and in this set will not be added to the output.
+     * @param newResourceObjects   Output set to which non-preexisting resources
+     *     will be added.
+     * @param recursive            Whether or not to add resources of resources.
+     */
+    void getResources(
+            const SkTSet<SkPDFObject*>& knownResourceObjects,
+            SkTSet<SkPDFObject*>* newResourceObjects,
+            bool recursive) const;
+
+    /**
+     * Gets the prefix associated with a resource type, like G for ExtGState
+     * or P for Pattern.
+     */
+    const char* getResourceTypePrefix(SkPDFResourceType type);

[vandebo (ex-Chrome), 2013/07/10 18:24:31]

return a char, instead of a c-string

[vandebo (ex-Chrome), 2013/07/10 18:24:31]

Not used publicly, make private.  Actually it doesn't use any instance
information so it can be a static function in the implementation file.

[ducky, 2013/07/10 22:54:34]

Now moved into a static function in the implementation file.
I see the logic behind making it a char, but that also seems to make the code
uglier, since SkString can't construct from a char, but rather needs a char[].

+    /**
+     * Gets the name of a resource type, like ExtGState or Pattern.
+     */
+    const char* getResourceTypeName(SkPDFResourceType type);

[vandebo (ex-Chrome), 2013/07/10 18:24:31]

Same as above.

[ducky, 2013/07/10 22:54:34]

Done.

+ private:

[vandebo (ex-Chrome), 2013/07/10 18:24:31]

nit: no indent.

[ducky, 2013/07/10 22:54:34]

Done.

+    /**
+     * Returns the sub-dict associated with the resource type type.
+     * If none currently exists, this will create a sub-dict and index it for
+     * future use.
+     */
+    SkPDFDict* getResourceTypeDict(SkPDFName* type);
+
+    SkTSet<SkPDFObject*> fResources;
+
+     struct DictRec {
+       SkPDFName* key;
+       SkPDFDict* value;
+     };
+     SkTDArray<struct DictRec> fTypes;
+};
+
+#endif