Make the Pepper proxy support in-process font rendering.

ppapi/shared_impl/font_impl.cc

+// Copyright (c) 2011 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 "ppapi/shared_impl/font_impl.h"
+
+#include "base/synchronization/waitable_event.h"
+#include "base/utf_string_conversions.h"
+#include "ppapi/c/dev/ppb_font_dev.h"
+#include "ppapi/c/pp_point.h"
+#include "ppapi/c/pp_rect.h"
+#include "skia/ext/platform_canvas.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebFont.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebFontDescription.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebRect.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebFloatPoint.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebFloatRect.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebTextRun.h"
+#include "webkit/glue/webkit_glue.h"
+
+using WebKit::WebFloatPoint;
+using WebKit::WebFloatRect;
+using WebKit::WebFont;
+using WebKit::WebFontDescription;
+using WebKit::WebRect;
+using WebKit::WebTextRun;
+
+namespace pp {
+namespace shared_impl {
+
+namespace {
+
+// The PP_* version lacks "None", so is just one value shifted from the
+// WebFontDescription version. These values are checked in
+// PPFontDescToWebFontDesc to make sure the conversion is correct. This is a
+// macro so it can also be used in the COMPILE_ASSERTS.
+#define PP_FONTFAMILY_TO_WEB_FONTFAMILY(f) \
+  static_cast<WebFontDescription::GenericFamily>(f + 1)
+
+// Assumes the given PP_FontDescription has been validated.
+WebFontDescription PPFontDescToWebFontDesc(const PP_FontDescription_Dev& font,
+                                           const std::string& face) {
+  // Verify that the enums match so we can just static cast.
+  COMPILE_ASSERT(static_cast<int>(WebFontDescription::Weight100) ==
+                 static_cast<int>(PP_FONTWEIGHT_100),
+                 FontWeight100);
+  COMPILE_ASSERT(static_cast<int>(WebFontDescription::Weight900) ==
+                 static_cast<int>(PP_FONTWEIGHT_900),
+                 FontWeight900);
+  COMPILE_ASSERT(WebFontDescription::GenericFamilyStandard ==
+                 PP_FONTFAMILY_TO_WEB_FONTFAMILY(PP_FONTFAMILY_DEFAULT),
+                 StandardFamily);
+  COMPILE_ASSERT(WebFontDescription::GenericFamilySerif ==
+                 PP_FONTFAMILY_TO_WEB_FONTFAMILY(PP_FONTFAMILY_SERIF),
+                 SerifFamily);
+  COMPILE_ASSERT(WebFontDescription::GenericFamilySansSerif ==
+                 PP_FONTFAMILY_TO_WEB_FONTFAMILY(PP_FONTFAMILY_SANSSERIF),
+                 SansSerifFamily);
+  COMPILE_ASSERT(WebFontDescription::GenericFamilyMonospace ==
+                 PP_FONTFAMILY_TO_WEB_FONTFAMILY(PP_FONTFAMILY_MONOSPACE),
+                 MonospaceFamily);
+
+  WebFontDescription result;
+  result.family = UTF8ToUTF16(face);
+  result.genericFamily = PP_FONTFAMILY_TO_WEB_FONTFAMILY(font.family);
+  result.size = static_cast<float>(font.size);
+  result.italic = font.italic != PP_FALSE;
+  result.smallCaps = font.small_caps != PP_FALSE;
+  result.weight = static_cast<WebFontDescription::Weight>(font.weight);
+  result.letterSpacing = static_cast<short>(font.letter_spacing);
+  result.wordSpacing = static_cast<short>(font.word_spacing);
+  return result;
+}
+
+WebTextRun TextRunToWebTextRun(const FontImpl::TextRun& run) {
+  return WebTextRun(UTF8ToUTF16(run.text),
+                    run.rtl != PP_FALSE,
+                    run.override_direction != PP_FALSE);
+}
+
+}  // namespace
+
+FontImpl::DrawTextParams::DrawTextParams(skia::PlatformCanvas* destination_arg,
+                                         const TextRun& text_arg,
+                                         const PP_Point* position_arg,
+                                         uint32_t color_arg,
+                                         const PP_Rect* clip_arg,
+                                         bool image_data_is_opaque_arg)
+    : destination(destination_arg),
+      text(text_arg),
+      position(position_arg),
+      color(color_arg),
+      clip(clip_arg),
+      image_data_is_opaque(image_data_is_opaque_arg) {
+}
+
+FontImpl::DrawTextParams::~DrawTextParams() {
+}
+
+FontImpl::FontImpl() {
+}
+
+FontImpl::~FontImpl() {
+}
+
+// static
+bool FontImpl::IsPPFontDescriptionValid(const PP_FontDescription_Dev& desc) {
+  // Check validity of string. We can't check the actual text since we could
+  // be on the wrong thread and don't know if we're in the plugin or the host.
+  if (desc.face.type != PP_VARTYPE_STRING &&
+      desc.face.type != PP_VARTYPE_UNDEFINED)
+    return false;
+
+  // Check enum ranges.
+  if (static_cast<int>(desc.family) < PP_FONTFAMILY_DEFAULT ||
+      static_cast<int>(desc.family) > PP_FONTFAMILY_MONOSPACE)
+    return false;
+  if (static_cast<int>(desc.weight) < PP_FONTWEIGHT_100 ||
+      static_cast<int>(desc.weight) > PP_FONTWEIGHT_900)
+    return false;
+
+  // Check for excessive sizes which may cause layout to get confused.
+  if (desc.size > 200)
+    return false;
+
+  return true;
+}
+
+void FontImpl::DoCreate(base::WaitableEvent* event,
+                        const PP_FontDescription_Dev& desc,
+                        const std::string& desc_face) {
+  WebFontDescription web_font_desc = PPFontDescToWebFontDesc(desc, desc_face);
+  font_.reset(WebFont::create(web_font_desc));
+  if (event)
+    event->Signal();
+}
+
+void FontImpl::DoDescribe(base::WaitableEvent* event,
+                          PP_FontDescription_Dev* description,
+                          std::string* face,
+                          PP_FontMetrics_Dev* metrics,
+                          PP_Bool* result) {
+  if (description->face.type != PP_VARTYPE_UNDEFINED) {
+    *result = PP_FALSE;
+  } else {
+    WebFontDescription web_desc = font_->fontDescription();
+
+    // While converting the other way in PPFontDescToWebFontDesc we validated
+    // that the enums can be casted.
+    description->face = PP_MakeUndefined();
+    description->family =
+        static_cast<PP_FontFamily_Dev>(web_desc.genericFamily);
+    description->size = static_cast<uint32_t>(web_desc.size);
+    description->weight = static_cast<PP_FontWeight_Dev>(web_desc.weight);
+    description->italic = web_desc.italic ? PP_TRUE : PP_FALSE;
+    description->small_caps = web_desc.smallCaps ? PP_TRUE : PP_FALSE;
+
+    *face = UTF16ToUTF8(web_desc.family);
+
+    metrics->height = font_->height();
+    metrics->ascent = font_->ascent();
+    metrics->descent = font_->descent();
+    metrics->line_spacing = font_->lineSpacing();
+    metrics->x_height = static_cast<int32_t>(font_->xHeight());
+
+    *result = PP_TRUE;
+  }
+  if (event)
+    event->Signal();
+}
+
+void FontImpl::DoDrawTextAt(base::WaitableEvent* event,
+                            const DrawTextParams& params) {
+  WebTextRun run = TextRunToWebTextRun(params.text);
+
+  // Convert position and clip.
+  WebFloatPoint web_position(static_cast<float>(params.position->x),
+                             static_cast<float>(params.position->y));
+  WebRect web_clip;
+  if (!params.clip) {
+    // Use entire canvas. SkCanvas doesn't have a size on it, so we just use
+    // the current clip bounds.
+    SkRect skclip;
+    params.destination->getClipBounds(&skclip);
+    web_clip = WebRect(skclip.fLeft, skclip.fTop, skclip.fRight - skclip.fLeft,
+                       skclip.fBottom - skclip.fTop);
+  } else {
+    web_clip = WebRect(params.clip->point.x, params.clip->point.y,
+                       params.clip->size.width, params.clip->size.height);
+  }
+
+  font_->drawText(webkit_glue::ToWebCanvas(params.destination),
+                  run, web_position, params.color, web_clip,
+                  params.image_data_is_opaque);
+  if (event)
+    event->Signal();
+}
+
+void FontImpl::DoMeasureText(base::WaitableEvent* event,
+                             const TextRun& text, int32_t* result) {
+  *result = font_->calculateWidth(TextRunToWebTextRun(text));
+  if (event)
+    event->Signal();
+}
+
+void FontImpl::DoCharacterOffsetForPixel(base::WaitableEvent* event,
+                                         const TextRun& text,
+                                         int32_t pixel_position,
+                                         uint32_t* result) {
+  *result = static_cast<uint32_t>(font_->offsetForPosition(
+      TextRunToWebTextRun(text), static_cast<float>(pixel_position)));
+  if (event)
+    event->Signal();
+}
+
+void FontImpl::DoPixelOffsetForCharacter(base::WaitableEvent* event,
+                                         const TextRun& text,
+                                         uint32_t char_offset,
+                                         int32_t* result) {
+  WebTextRun run = TextRunToWebTextRun(text);
+  if (char_offset >= run.text.length()) {
+    *result = -1;
+  } else {
+    WebFloatRect rect = font_->selectionRectForText(
+        run, WebFloatPoint(0.0f, 0.0f), font_->height(), 0, char_offset);
+    *result = static_cast<int>(rect.width);
+  }
+  if (event)
+    event->Signal();
+}
+
+}  // namespace shared_impl
+}  // namespace pp