Implemented transparent gradients

src/pdf/SkPDFFormXObject.cpp

 
 /*
  * Copyright 2010 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkPDFFormXObject.h"
 
 #include "SkMatrix.h"
 #include "SkPDFCatalog.h"
 #include "SkPDFDevice.h"
 #include "SkPDFUtils.h"
 #include "SkStream.h"
 #include "SkTypes.h"
 
 SkPDFFormXObject::SkPDFFormXObject(SkPDFDevice* device) {
     // We don't want to keep around device because we'd have two copies
     // of content, so reference or copy everything we need (content and
     // resources).
     SkTSet<SkPDFObject*> emptySet;
     device->getResources(emptySet, &fResources, false);
 
     SkAutoTUnref<SkStream> content(device->content());
     setData(content.get());
 
-    insertName("Type", "XObject");
-    insertName("Subtype", "Form");
     SkSafeUnref(this->insert("BBox", device->copyMediaBox()));
     insert("Resources", device->getResourceDict());
 
     // We invert the initial transform and apply that to the xobject so that
     // it doesn't get applied twice. We can't just undo it because it's
     // embedded in things like shaders and images.
     if (!device->initialTransform().isIdentity()) {
         SkMatrix inverse;
         if (!device->initialTransform().invert(&inverse)) {
             // The initial transform should be invertible.
             SkASSERT(false);
             inverse.reset();
         }
         insert("Matrix", SkPDFUtils::MatrixToArray(inverse))->unref();
     }
 
+    commonInit(NULL);

[vandebo (ex-Chrome), 2013/07/08 19:02:25]

nit: move to line 28

[ducky, 2013/07/09 02:56:23]

Done.

+}
+
+/**
+ * Creates a FormXObject from a content stream and associated resources.
+ */
+SkPDFFormXObject::SkPDFFormXObject(SkData* content, SkRect bbox,
+                                   SkPDFResourceDict* resourceDict) {
+    SkTSet<SkPDFObject*> emptySet;
+    SkSafeUnref(this->insert("BBox", SkPDFUtils::RectToArray(bbox)));
+    insert("Resources", resourceDict);
+    resourceDict->ref();
+    resourceDict->getResources(emptySet, &fResources);
+
+    setData(content);
+
+    commonInit("DeviceRGB");
+}
+
+void SkPDFFormXObject::commonInit(const char colorSpace[]) {

[vandebo (ex-Chrome), 2013/07/08 19:02:25]

pass as much as possible into init. i.e. bbox and resourceDict

[ducky, 2013/07/09 02:56:23]

Done. Though, it's still not a completely clean solution, as bbox is now unref'd
inside init (while being created outside init) and the different resourceDict
styles mean different code exists to handle resources. Should the new
resourceDict style work, this may become much cleaner.

[vandebo (ex-Chrome), 2013/07/09 17:47:44]

As you pointed out at a different point, you probably want to own the object on
the calling side.

At the least, the ownership semantics should be documented and preferably be the
same for all the arguments.

[ducky, 2013/07/10 21:42:26]

Fixed. Ownership is no longer transferred, and the caller is responsible for
cleaning up. Two more lines of boilerplate, but should be more intuitive.

+    insertName("Type", "XObject");
+    insertName("Subtype", "Form");
+
     // Right now SkPDFFormXObject is only used for saveLayer, which implies
     // isolated blending.  Do this conditionally if that changes.
     SkAutoTUnref<SkPDFDict> group(new SkPDFDict("Group"));
     group->insertName("S", "Transparency");
+
+    if (colorSpace != NULL) {
+        group->insertName("CS", colorSpace);
+    }
     group->insert("I", new SkPDFBool(true))->unref();  // Isolated.
     insert("Group", group.get());
 }
 
 SkPDFFormXObject::~SkPDFFormXObject() {
     fResources.unrefAll();
 }
 
 void SkPDFFormXObject::getResources(
         const SkTSet<SkPDFObject*>& knownResourceObjects,
         SkTSet<SkPDFObject*>* newResourceObjects) {
     GetResourcesHelper(&fResources.toArray(),
                        knownResourceObjects,
                        newResourceObjects);
 }