Implement direct write fallback proxy

content/child/dwrite_font_proxy/font_fallback_win_unittest.cc

+// Copyright 2016 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.
+
+#include "content/child/dwrite_font_proxy/font_fallback_win.h"
+
+#include <dwrite.h>
+#include <shlobj.h>
+#include <wrl.h>
+
+#include <vector>
+
+#include "base/memory/ref_counted.h"
+#include "content/child/dwrite_font_proxy/dwrite_font_proxy_win.h"
+#include "content/common/dwrite_text_analysis_source_win.h"
+#include "content/test/dwrite_font_fake_sender_win.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace mswr = Microsoft::WRL;
+
+namespace content {
+
+namespace {
+
+class FontFallbackUnitTest : public testing::Test {
+ public:
+  FontFallbackUnitTest() {
+    CreateDWriteFactory(&factory_);
+
+    factory_->CreateNumberSubstitution(DWRITE_NUMBER_SUBSTITUTION_METHOD_NONE,
+                                       L"en-us", true /* ignoreUserOverride */,
+                                       &number_substitution_);
+
+    std::vector<base::char16> font_path;
+    font_path.resize(MAX_PATH);
+    SHGetSpecialFolderPath(nullptr /* hwndOwner - reserved */, font_path.data(),
+                           CSIDL_FONTS, FALSE /* fCreate*/);
+    base::string16 arial_path;
+    arial_path.append(font_path.data()).append(L"\\arial.ttf");
+
+    fake_collection_ = new FakeFontCollection();
+    fake_collection_->AddFont(L"Arial")
+        .AddFamilyName(L"en-us", L"Arial")
+        .AddFilePath(arial_path);
+
+    mswr::MakeAndInitialize<DWriteFontCollectionProxy>(
+        &collection_, factory_.Get(), fake_collection_->GetSender());
+  }
+
+  void CreateDWriteFactory(IUnknown** factory) {
+    using DWriteCreateFactoryProc = decltype(DWriteCreateFactory)*;
+    HMODULE dwrite_dll = LoadLibraryW(L"dwrite.dll");
+    if (!dwrite_dll)
+      return;
+
+    DWriteCreateFactoryProc dwrite_create_factory_proc =
+        reinterpret_cast<DWriteCreateFactoryProc>(
+            GetProcAddress(dwrite_dll, "DWriteCreateFactory"));
+    if (!dwrite_create_factory_proc)
+      return;
+
+    dwrite_create_factory_proc(DWRITE_FACTORY_TYPE_SHARED,
+                               __uuidof(IDWriteFactory), factory);
+  }
+
+  scoped_refptr<FakeFontCollection> fake_collection_;
+  mswr::ComPtr<IDWriteFactory> factory_;
+  mswr::ComPtr<DWriteFontCollectionProxy> collection_;
+  mswr::ComPtr<IDWriteNumberSubstitution> number_substitution_;
+};
+
+TEST_F(FontFallbackUnitTest, MapCharacters) {
+  mswr::ComPtr<FontFallback> fallback;
+  mswr::MakeAndInitialize<FontFallback>(&fallback, collection_.Get(),
+                                        fake_collection_->GetTrackingSender());
+
+  mswr::ComPtr<IDWriteFont> font;
+  UINT32 mapped_length = 0;
+  float scale = 0.0;
+
+  mswr::ComPtr<TextAnalysisSource> text;
+  mswr::MakeAndInitialize<TextAnalysisSource>(
+      &text, L"hello", L"en-us", number_substitution_.Get(),
+      DWRITE_READING_DIRECTION_LEFT_TO_RIGHT);
+  fallback->MapCharacters(text.Get(), 0, 1, nullptr, nullptr,
+                          DWRITE_FONT_WEIGHT_NORMAL, DWRITE_FONT_STYLE_NORMAL,
+                          DWRITE_FONT_STRETCH_NORMAL, &mapped_length, &font,
+                          &scale);
+
+  EXPECT_EQ(1u, mapped_length);  // The fake sender only maps one character
+  EXPECT_NE(nullptr, font.Get());
+}
+
+}  // namespace
+}  // namespace content