Implemented transparent gradients

src/pdf/SkPDFFormXObject.cpp

Index: src/pdf/SkPDFFormXObject.cpp
diff --git a/src/pdf/SkPDFFormXObject.cpp b/src/pdf/SkPDFFormXObject.cpp
index 884e6db2e4a1535c20d6f1dd62e87e637eceb2c1..c309d5e85ca909f19d90928959d212aec16beab9 100644
--- a/src/pdf/SkPDFFormXObject.cpp
+++ b/src/pdf/SkPDFFormXObject.cpp
@@ -16,6 +16,16 @@
 #include "SkStream.h"
 #include "SkTypes.h"
 
+static SkPDFArray* rectToArray(SkRect rect) {

[vandebo (ex-Chrome), 2013/07/03 17:07:01]

Put this in SkPDFUtil and use it in SkPDFDevice::copyMediaBox().

[ducky, 2013/07/03 23:32:09]

Done.

+    SkPDFArray* mediaBox = SkNEW(SkPDFArray);
+    mediaBox->reserve(4);
+    mediaBox->appendScalar(rect.left());
+    mediaBox->appendScalar(rect.top());
+    mediaBox->appendScalar(rect.right());
+    mediaBox->appendScalar(rect.bottom());
+    return mediaBox;
+}
+
 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
@@ -52,6 +62,31 @@ SkPDFFormXObject::SkPDFFormXObject(SkPDFDevice* device) {
     insert("Group", group.get());
 }
 
+/**
+ * Creates a FormXObject from a content stream and associated resources.
+ */
+SkPDFFormXObject::SkPDFFormXObject(SkStream* content,
+                                   SkPDFDict* resourceDict,
+                                   SkTSet<SkPDFObject*>& resources,
+                                   SkRect bbox) {
+    setData(content);

[vandebo (ex-Chrome), 2013/07/03 17:07:01]

This whole body can be shared with the other constructor.  Pull it out into a
private init method (since you can't call one constructor from another). 

[ducky, 2013/07/03 23:32:09]

Done.

+    resourceDict->ref();

[vandebo (ex-Chrome), 2013/07/03 17:07:01]

This should be next to where the reference is used.

[ducky, 2013/07/03 23:32:09]

Done.

+
+    insertName("Type", "XObject");
+    insertName("Subtype", "Form");
+    SkSafeUnref(this->insert("BBox", rectToArray(bbox)));
+    insert("Resources", resourceDict);
+    fResources = resources;
+
+    // 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");
+    group->insertName("CS", "DeviceRGB");
+    group->insert("I", new SkPDFBool(true))->unref();  // Isolated.
+    insert("Group", group.get());
+}
+
 SkPDFFormXObject::~SkPDFFormXObject() {
     fResources.unrefAll();
 }