1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "content/child/browser_font_resource_trusted.h" 6 7 #include "base/strings/string_util.h" 8 #include "base/strings/utf_string_conversions.h" 9 #include "ppapi/c/dev/ppb_font_dev.h" 10 #include "ppapi/proxy/connection.h" 11 #include "ppapi/shared_impl/ppapi_preferences.h" 12 #include "ppapi/shared_impl/var.h" 13 #include "ppapi/thunk/enter.h" 14 #include "ppapi/thunk/ppb_image_data_api.h" 15 #include "ppapi/thunk/thunk.h" 16 #include "skia/ext/platform_canvas.h" 17 #include "third_party/WebKit/public/platform/WebCanvas.h" 18 #include "third_party/WebKit/public/platform/WebFloatPoint.h" 19 #include "third_party/WebKit/public/platform/WebFloatRect.h" 20 #include "third_party/WebKit/public/platform/WebRect.h" 21 #include "third_party/WebKit/public/web/WebFont.h" 22 #include "third_party/WebKit/public/web/WebFontDescription.h" 23 #include "third_party/WebKit/public/web/WebTextRun.h" 24 #include "third_party/icu/source/common/unicode/ubidi.h" 25 #include "third_party/skia/include/core/SkRect.h" 26 27 using ppapi::StringVar; 28 using ppapi::thunk::EnterResourceNoLock; 29 using ppapi::thunk::PPB_ImageData_API; 30 using blink::WebFloatPoint; 31 using blink::WebFloatRect; 32 using blink::WebFont; 33 using blink::WebFontDescription; 34 using blink::WebRect; 35 using blink::WebTextRun; 36 using blink::WebCanvas; 37 38 namespace content { 39 40 namespace { 41 42 // Same as WebPreferences::kCommonScript. I'd use that directly here, but get an 43 // undefined reference linker error. 44 const char kCommonScript[] = "Zyyy"; 45 46 base::string16 GetFontFromMap( 47 const webkit_glue::ScriptFontFamilyMap& map, 48 const std::string& script) { 49 webkit_glue::ScriptFontFamilyMap::const_iterator it = 50 map.find(script); 51 if (it != map.end()) 52 return it->second; 53 return base::string16(); 54 } 55 56 // Splits a PP_BrowserFont_Trusted_TextRun into a sequence or LTR and RTL 57 // WebTextRuns that can be used for WebKit. Normally WebKit does this for us, 58 // but the font drawing and measurement routines we call happen after this 59 // step. So for correct rendering of RTL content, we need to do it ourselves. 60 class TextRunCollection { 61 public: 62 explicit TextRunCollection(const PP_BrowserFont_Trusted_TextRun& run) 63 : bidi_(NULL), 64 num_runs_(0) { 65 StringVar* text_string = StringVar::FromPPVar(run.text); 66 if (!text_string) 67 return; // Leave num_runs_ = 0 so we'll do nothing. 68 text_ = UTF8ToUTF16(text_string->value()); 69 70 if (run.override_direction) { 71 // Skip autodetection. 72 num_runs_ = 1; 73 override_run_ = WebTextRun(text_, PP_ToBool(run.rtl), true); 74 } else { 75 bidi_ = ubidi_open(); 76 UErrorCode uerror = U_ZERO_ERROR; 77 ubidi_setPara(bidi_, text_.data(), text_.size(), run.rtl, NULL, &uerror); 78 if (U_SUCCESS(uerror)) 79 num_runs_ = ubidi_countRuns(bidi_, &uerror); 80 } 81 } 82 83 ~TextRunCollection() { 84 if (bidi_) 85 ubidi_close(bidi_); 86 } 87 88 const base::string16& text() const { return text_; } 89 int num_runs() const { return num_runs_; } 90 91 // Returns a WebTextRun with the info for the run at the given index. 92 // The range covered by the run is in the two output params. 93 WebTextRun GetRunAt(int index, int32_t* run_start, int32_t* run_len) const { 94 DCHECK(index < num_runs_); 95 if (bidi_) { 96 bool run_rtl = !!ubidi_getVisualRun(bidi_, index, run_start, run_len); 97 return WebTextRun(base::string16(&text_[*run_start], *run_len), 98 run_rtl, true); 99 } 100 101 // Override run, return the single one. 102 DCHECK(index == 0); 103 *run_start = 0; 104 *run_len = static_cast<int32_t>(text_.size()); 105 return override_run_; 106 } 107 108 private: 109 // Will be null if we skipped autodetection. 110 UBiDi* bidi_; 111 112 // Text of all the runs. 113 base::string16 text_; 114 115 int num_runs_; 116 117 // When the content specifies override_direction (bidi_ is null) then this 118 // will contain the single text run for WebKit. 119 WebTextRun override_run_; 120 121 DISALLOW_COPY_AND_ASSIGN(TextRunCollection); 122 }; 123 124 bool PPTextRunToWebTextRun(const PP_BrowserFont_Trusted_TextRun& text, 125 WebTextRun* run) { 126 StringVar* text_string = StringVar::FromPPVar(text.text); 127 if (!text_string) 128 return false; 129 130 *run = WebTextRun(UTF8ToUTF16(text_string->value()), 131 PP_ToBool(text.rtl), 132 PP_ToBool(text.override_direction)); 133 return true; 134 } 135 136 // The PP_* version lacks "None", so is just one value shifted from the 137 // WebFontDescription version. These values are checked in 138 // PPFontDescToWebFontDesc to make sure the conversion is correct. This is a 139 // macro so it can also be used in the COMPILE_ASSERTS. 140 #define PP_FAMILY_TO_WEB_FAMILY(f) \ 141 static_cast<WebFontDescription::GenericFamily>(f + 1) 142 143 // Assumes the given PP_FontDescription has been validated. 144 WebFontDescription PPFontDescToWebFontDesc( 145 const PP_BrowserFont_Trusted_Description& font, 146 const ppapi::Preferences& prefs) { 147 // Verify that the enums match so we can just static cast. 148 COMPILE_ASSERT(static_cast<int>(WebFontDescription::Weight100) == 149 static_cast<int>(PP_BROWSERFONT_TRUSTED_WEIGHT_100), 150 FontWeight100); 151 COMPILE_ASSERT(static_cast<int>(WebFontDescription::Weight900) == 152 static_cast<int>(PP_BROWSERFONT_TRUSTED_WEIGHT_900), 153 FontWeight900); 154 COMPILE_ASSERT(WebFontDescription::GenericFamilyStandard == 155 PP_FAMILY_TO_WEB_FAMILY(PP_FONTFAMILY_DEFAULT), 156 StandardFamily); 157 COMPILE_ASSERT(WebFontDescription::GenericFamilySerif == 158 PP_FAMILY_TO_WEB_FAMILY(PP_FONTFAMILY_SERIF), 159 SerifFamily); 160 COMPILE_ASSERT(WebFontDescription::GenericFamilySansSerif == 161 PP_FAMILY_TO_WEB_FAMILY(PP_FONTFAMILY_SANSSERIF), 162 SansSerifFamily); 163 COMPILE_ASSERT(WebFontDescription::GenericFamilyMonospace == 164 PP_FAMILY_TO_WEB_FAMILY(PP_FONTFAMILY_MONOSPACE), 165 MonospaceFamily); 166 167 StringVar* face_name = StringVar::FromPPVar(font.face); // Possibly null. 168 169 WebFontDescription result; 170 base::string16 resolved_family; 171 if (!face_name || face_name->value().empty()) { 172 // Resolve the generic family. 173 switch (font.family) { 174 case PP_BROWSERFONT_TRUSTED_FAMILY_SERIF: 175 resolved_family = GetFontFromMap(prefs.serif_font_family_map, 176 kCommonScript); 177 break; 178 case PP_BROWSERFONT_TRUSTED_FAMILY_SANSSERIF: 179 resolved_family = GetFontFromMap(prefs.sans_serif_font_family_map, 180 kCommonScript); 181 break; 182 case PP_BROWSERFONT_TRUSTED_FAMILY_MONOSPACE: 183 resolved_family = GetFontFromMap(prefs.fixed_font_family_map, 184 kCommonScript); 185 break; 186 case PP_BROWSERFONT_TRUSTED_FAMILY_DEFAULT: 187 default: 188 resolved_family = GetFontFromMap(prefs.standard_font_family_map, 189 kCommonScript); 190 break; 191 } 192 } else { 193 // Use the exact font. 194 resolved_family = UTF8ToUTF16(face_name->value()); 195 } 196 result.family = resolved_family; 197 198 result.genericFamily = PP_FAMILY_TO_WEB_FAMILY(font.family); 199 200 if (font.size == 0) { 201 // Resolve the default font size, using the resolved family to see if 202 // we should use the fixed or regular font size. It's difficult at this 203 // level to detect if the requested font is fixed width, so we only apply 204 // the alternate font size to the default fixed font family. 205 if (StringToLowerASCII(resolved_family) == 206 StringToLowerASCII(GetFontFromMap(prefs.fixed_font_family_map, 207 kCommonScript))) 208 result.size = static_cast<float>(prefs.default_fixed_font_size); 209 else 210 result.size = static_cast<float>(prefs.default_font_size); 211 } else { 212 // Use the exact size. 213 result.size = static_cast<float>(font.size); 214 } 215 216 result.italic = font.italic != PP_FALSE; 217 result.smallCaps = font.small_caps != PP_FALSE; 218 result.weight = static_cast<WebFontDescription::Weight>(font.weight); 219 result.letterSpacing = static_cast<short>(font.letter_spacing); 220 result.wordSpacing = static_cast<short>(font.word_spacing); 221 return result; 222 } 223 224 } // namespace 225 226 // static 227 bool BrowserFontResource_Trusted::IsPPFontDescriptionValid( 228 const PP_BrowserFont_Trusted_Description& desc) { 229 // Check validity of string. We can't check the actual text since we could 230 // be on the wrong thread and don't know if we're in the plugin or the host. 231 if (desc.face.type != PP_VARTYPE_STRING && 232 desc.face.type != PP_VARTYPE_UNDEFINED) 233 return false; 234 235 // Check enum ranges. 236 if (static_cast<int>(desc.family) < PP_BROWSERFONT_TRUSTED_FAMILY_DEFAULT || 237 static_cast<int>(desc.family) > PP_BROWSERFONT_TRUSTED_FAMILY_MONOSPACE) 238 return false; 239 if (static_cast<int>(desc.weight) < PP_BROWSERFONT_TRUSTED_WEIGHT_100 || 240 static_cast<int>(desc.weight) > PP_BROWSERFONT_TRUSTED_WEIGHT_900) 241 return false; 242 243 // Check for excessive sizes which may cause layout to get confused. 244 if (desc.size > 200) 245 return false; 246 247 return true; 248 } 249 250 BrowserFontResource_Trusted::BrowserFontResource_Trusted( 251 ppapi::proxy::Connection connection, 252 PP_Instance instance, 253 const PP_BrowserFont_Trusted_Description& desc, 254 const ppapi::Preferences& prefs) 255 : PluginResource(connection, instance), 256 font_(WebFont::create(PPFontDescToWebFontDesc(desc, prefs))) { 257 } 258 259 BrowserFontResource_Trusted::~BrowserFontResource_Trusted() { 260 } 261 262 ppapi::thunk::PPB_BrowserFont_Trusted_API* 263 BrowserFontResource_Trusted::AsPPB_BrowserFont_Trusted_API() { 264 return this; 265 } 266 267 PP_Bool BrowserFontResource_Trusted::Describe( 268 PP_BrowserFont_Trusted_Description* description, 269 PP_BrowserFont_Trusted_Metrics* metrics) { 270 if (description->face.type != PP_VARTYPE_UNDEFINED) 271 return PP_FALSE; 272 273 // While converting the other way in PPFontDescToWebFontDesc we validated 274 // that the enums can be casted. 275 WebFontDescription web_desc = font_->fontDescription(); 276 description->face = StringVar::StringToPPVar(UTF16ToUTF8(web_desc.family)); 277 description->family = 278 static_cast<PP_BrowserFont_Trusted_Family>(web_desc.genericFamily); 279 description->size = static_cast<uint32_t>(web_desc.size); 280 description->weight = static_cast<PP_BrowserFont_Trusted_Weight>( 281 web_desc.weight); 282 description->italic = web_desc.italic ? PP_TRUE : PP_FALSE; 283 description->small_caps = web_desc.smallCaps ? PP_TRUE : PP_FALSE; 284 description->letter_spacing = static_cast<int32_t>(web_desc.letterSpacing); 285 description->word_spacing = static_cast<int32_t>(web_desc.wordSpacing); 286 287 metrics->height = font_->height(); 288 metrics->ascent = font_->ascent(); 289 metrics->descent = font_->descent(); 290 metrics->line_spacing = font_->lineSpacing(); 291 metrics->x_height = static_cast<int32_t>(font_->xHeight()); 292 293 // Convert the string. 294 return PP_TRUE; 295 } 296 297 PP_Bool BrowserFontResource_Trusted::DrawTextAt( 298 PP_Resource image_data, 299 const PP_BrowserFont_Trusted_TextRun* text, 300 const PP_Point* position, 301 uint32_t color, 302 const PP_Rect* clip, 303 PP_Bool image_data_is_opaque) { 304 PP_Bool result = PP_FALSE; 305 // Get and map the image data we're painting to. 306 EnterResourceNoLock<PPB_ImageData_API> enter(image_data, true); 307 if (enter.failed()) 308 return result; 309 310 PPB_ImageData_API* image = static_cast<PPB_ImageData_API*>( 311 enter.object()); 312 SkCanvas* canvas = image->GetPlatformCanvas(); 313 bool needs_unmapping = false; 314 if (!canvas) { 315 needs_unmapping = true; 316 image->Map(); 317 canvas = image->GetPlatformCanvas(); 318 if (!canvas) 319 return result; // Failure mapping. 320 } 321 322 DrawTextToCanvas(canvas, *text, position, color, clip, image_data_is_opaque); 323 324 if (needs_unmapping) 325 image->Unmap(); 326 return PP_TRUE; 327 } 328 329 int32_t BrowserFontResource_Trusted::MeasureText( 330 const PP_BrowserFont_Trusted_TextRun* text) { 331 WebTextRun run; 332 if (!PPTextRunToWebTextRun(*text, &run)) 333 return -1; 334 return font_->calculateWidth(run); 335 } 336 337 uint32_t BrowserFontResource_Trusted::CharacterOffsetForPixel( 338 const PP_BrowserFont_Trusted_TextRun* text, 339 int32_t pixel_position) { 340 TextRunCollection runs(*text); 341 int32_t cur_pixel_offset = 0; 342 for (int i = 0; i < runs.num_runs(); i++) { 343 int32_t run_begin = 0; 344 int32_t run_len = 0; 345 WebTextRun run = runs.GetRunAt(i, &run_begin, &run_len); 346 int run_width = font_->calculateWidth(run); 347 if (pixel_position < cur_pixel_offset + run_width) { 348 // Offset is in this run. 349 return static_cast<uint32_t>(font_->offsetForPosition( 350 run, static_cast<float>(pixel_position - cur_pixel_offset))) + 351 run_begin; 352 } 353 cur_pixel_offset += run_width; 354 } 355 return runs.text().size(); 356 } 357 358 int32_t BrowserFontResource_Trusted::PixelOffsetForCharacter( 359 const PP_BrowserFont_Trusted_TextRun* text, 360 uint32_t char_offset) { 361 TextRunCollection runs(*text); 362 int32_t cur_pixel_offset = 0; 363 for (int i = 0; i < runs.num_runs(); i++) { 364 int32_t run_begin = 0; 365 int32_t run_len = 0; 366 WebTextRun run = runs.GetRunAt(i, &run_begin, &run_len); 367 if (char_offset >= static_cast<uint32_t>(run_begin) && 368 char_offset < static_cast<uint32_t>(run_begin + run_len)) { 369 // Character we're looking for is in this run. 370 // 371 // Here we ask WebKit to give us the rectangle around the character in 372 // question, and then return the left edge. If we asked for a range of 373 // 0 characters starting at the character in question, it would give us 374 // a 0-width rect around the insertion point. But that will be on the 375 // right side of the character for an RTL run, which would be wrong. 376 WebFloatRect rect = font_->selectionRectForText( 377 run, WebFloatPoint(0.0f, 0.0f), font_->height(), 378 char_offset - run_begin, char_offset - run_begin + 1); 379 return cur_pixel_offset + static_cast<int>(rect.x); 380 } else { 381 // Character is past this run, account for the pixels and continue 382 // looking. 383 cur_pixel_offset += font_->calculateWidth(run); 384 } 385 } 386 return -1; // Requested a char beyond the end. 387 } 388 389 void BrowserFontResource_Trusted::DrawTextToCanvas( 390 SkCanvas* destination, 391 const PP_BrowserFont_Trusted_TextRun& text, 392 const PP_Point* position, 393 uint32_t color, 394 const PP_Rect* clip, 395 PP_Bool image_data_is_opaque) { 396 // Convert position and clip. 397 WebFloatPoint web_position(static_cast<float>(position->x), 398 static_cast<float>(position->y)); 399 WebRect web_clip; 400 if (!clip) { 401 // Use entire canvas. SkCanvas doesn't have a size on it, so we just use 402 // the current clip bounds. 403 SkRect skclip; 404 destination->getClipBounds(&skclip); 405 web_clip = WebRect(skclip.fLeft, skclip.fTop, skclip.fRight - skclip.fLeft, 406 skclip.fBottom - skclip.fTop); 407 } else { 408 web_clip = WebRect(clip->point.x, clip->point.y, 409 clip->size.width, clip->size.height); 410 } 411 412 TextRunCollection runs(text); 413 for (int i = 0; i < runs.num_runs(); i++) { 414 int32_t run_begin = 0; 415 int32_t run_len = 0; 416 WebTextRun run = runs.GetRunAt(i, &run_begin, &run_len); 417 font_->drawText(destination, run, web_position, color, web_clip, 418 PP_ToBool(image_data_is_opaque)); 419 420 // Advance to the next run. Note that we avoid doing this for the last run 421 // since it's unnecessary, measuring text is slow, and most of the time 422 // there will be only one run anyway. 423 if (i != runs.num_runs() - 1) 424 web_position.x += font_->calculateWidth(run); 425 } 426 } 427 428 } // namespace content 429
