add SkCreateDataProviderFromStream to SkCGUtils

implement SkFontHost create_from_file/stream using SkCGUtils



git-svn-id: http://skia.googlecode.com/svn/trunk@3249 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 59 insertions, 0 deletions

diff --git a/src/utils/mac/SkStream_mac.cpp b/src/utils/mac/SkStream_mac.cpp
new file mode 100644
index 0000000000..97df43055c
--- /dev/null
+++ b/src/utils/mac/SkStream_mac.cpp
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkCGUtils.h"
+#include "SkStream.h"
+
+// This is used by CGDataProviderCreateWithData
+
+static void unref_data_proc(void* info, const void* addr, size_t size) {
+    SkASSERT(info);
+    ((SkRefCnt*)info)->unref();
+}
+
+// These are used by CGDataProviderSequentialCallbacks
+
+size_t get_bytes_proc(void* info, void* buffer, size_t bytes) {
+    SkASSERT(info);
+    return ((SkStream*)info)->read(buffer, bytes);
+}
+
+static off_t skip_forward_proc(void* info, off_t bytes) {
+    return ((SkStream*)info)->skip(bytes);
+}
+
+static void rewind_proc(void* info) {
+    SkASSERT(info);
+    ((SkStream*)info)->rewind();
+}
+
+static void release_info_proc(void* info) {
+    SkASSERT(info);
+    ((SkStream*)info)->unref();
+}
+
+CGDataProviderRef SkCreateDataProviderFromStream(SkStream* stream) {
+    stream->ref();  // unref will be called when the provider is deleted
+
+    const void* addr = stream->getMemoryBase();
+    if (addr) {
+        // special-case when the stream is just a block of ram
+        return CGDataProviderCreateWithData(stream, addr, stream->getLength(),
+                                            unref_data_proc);
+    }
+
+    CGDataProviderSequentialCallbacks rec;
+    sk_bzero(&rec, sizeof(rec));
+    rec.version = 0;
+    rec.getBytes = get_bytes_proc;
+    rec.skipForward = skip_forward_proc;
+    rec.rewind = rewind_proc;
+    rec.releaseInfo = release_info_proc;
+    return CGDataProviderCreateSequential(stream, &rec);
+}
+
+