Android content shell bringup.

content/browser/android/jni_helper.h

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_BROWSER_ANDROID_JNI_HELPER_H_
+#define CONTENT_BROWSER_ANDROID_JNI_HELPER_H_
+
+#include <jni.h>
+#include <string>
+#include <vector>
+
+#include "base/android/scoped_java_ref.h"
+#include "base/string16.h"
+#include "ui/gfx/rect.h"
+
+class SkBitmap;
+namespace gfx {
+  class Size;

[Avi (use Gerrit), 2012/05/09 18:48:28]

no indentation

[John Grabowski, 2012/05/09 19:03:57]

Done.

+}
+
+// Auto creator/destructor for a JNI frame for local references.  This allows
+// safely having more than 16 local references, and avoids calls to
+// DeleteLocalRef.
+// This should be created on the stack.
+class AutoLocalFrame {
+ public:
+  AutoLocalFrame(int capacity);
+  ~AutoLocalFrame();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(AutoLocalFrame);
+};
+
+// Create this object on the stack to obtain the pixels of a Java Bitmap and
+// automatically release them on destruction.
+// Similar to SkAutoLockPixels, except that it operates on a Java Bitmap
+// object via the Android NDK.
+class AutoLockJavaBitmap {
+ public:
+  AutoLockJavaBitmap(jobject bitmap);
+  ~AutoLockJavaBitmap();
+
+  void* pixels() const { return pixels_; }
+  gfx::Size size() const;
+  // Formats are in android/bitmap.h; e.g. ANDROID_BITMAP_FORMAT_RGBA_8888 */
+  int format() const;
+  uint32_t stride() const;
+
+ private:
+  jobject bitmap_;
+  void* pixels_;
+
+  DISALLOW_COPY_AND_ASSIGN(AutoLockJavaBitmap);
+};
+
+// Tell Java to write its current stack trace into Android logs.  Note that the
+// trace will stop at the entry point into C++ code.
+void PrintJavaStackTrace();
+
+// Fills in the given vector<string> from a java String[].
+void ConvertJavaArrayOfStringsToVectorOfStrings(
+    JNIEnv* env,
+    jobjectArray jstrings,
+    std::vector<std::string>* vec);
+
+// Helper method to create an Android Java Bitmap object.  You can use the
+// AutoLockJavaBitmap class to manipulate its pixels, and pass it back up
+// to Java code for drawing.  Returns a JNI local reference to the bitmap.
+// If 'keep' is true, then a reference will be kept in a static Java data
+// structure to prevent GC.  In that case, you must call DeleteJavaBitmap() to
+// garbage collect it.
+base::android::ScopedJavaLocalRef<jobject> CreateJavaBitmap(
+    const gfx::Size& size, bool keep);
+void DeleteJavaBitmap(jobject bitmap);
+
+// Paint one java bitmap into another.  Scale if needed.
+void PaintJavaBitmapToJavaBitmap(jobject sourceBitmap,
+                                 const gfx::Rect& sourceRect,
+                                 jobject destBitmap,
+                                 const gfx::Rect& destRect);
+
+// Copy the Chromium Skia bitmap into a new Java bitmap.  Useful for small UI
+// bitmaps originating from WebKit that we want to manipulate in Java (such as
+// favicons).  Due to the extra copy, should be avoided for large or frequently
+// used bitmaps.  Returns a local reference to the new bitmap.
+base::android::ScopedJavaLocalRef<jobject> ConvertToJavaBitmap(
+    const SkBitmap* skbitmap);
+
+// Registers our JNI methods.
+bool RegisterJniHelper(JNIEnv* env);
+
+#endif  // CONTENT_BROWSER_ANDROID_JNI_HELPER_H_