Fix RTL and complex script title in print preview header/footer.

chrome/renderer/print_web_view_helper_win.cc

Index: chrome/renderer/print_web_view_helper_win.cc
diff --git a/chrome/renderer/print_web_view_helper_win.cc b/chrome/renderer/print_web_view_helper_win.cc
index 4ee351ba67cfc6c271a6d5aa113560abf9dac663..1128e01a5790cff22e35a0a4d04be4dbbea09320 100644
--- a/chrome/renderer/print_web_view_helper_win.cc
+++ b/chrome/renderer/print_web_view_helper_win.cc
@@ -4,6 +4,7 @@
 
 #include "chrome/renderer/print_web_view_helper.h"
 
+#include "base/i18n/rtl.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/histogram.h"
@@ -20,6 +21,7 @@
 #include "skia/ext/vector_canvas.h"
 #include "skia/ext/platform_device.h"
 #include "third_party/skia/include/core/SkRefCnt.h"
+#include "third_party/skia/include/ports/SkTypeface_win.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
 #include "ui/gfx/gdi_util.h"
 #include "ui/gfx/point.h"
@@ -327,3 +329,100 @@ bool PrintWebViewHelper::CopyMetafileDataToSharedMem(
                                          shared_mem_handle));
   return true;
 }
+
+#if defined(USE_SKIA)
+
+// Uniscribe generation is very time consuming so a global cache for previous
+// results are needed.
+SCRIPT_CACHE PrintWebViewHelper::g_script_cache_;
+SCRIPT_ANALYSIS PrintWebViewHelper::g_script_analysis_;

[jungshik at Google, 2012/01/06 22:38:45]

In the past, we used to have UniscribeHelper class in chrome's tree instead of
Webkit expecting this kind of 'non-Webkit' usage. A few years ago, we moved
inside Webkit. 

I wonder if we have to take it out again (eventually). 

@xji: what's your plan for RenderText on Windows? 

[xji, 2012/01/07 01:21:15]

Mike (msw@) implemented RenderText in Windows.
The ConvertTextToGlyphs is very similar to RenderTextWin::EnsureLayout(). 
It would be nice and the way to go to use RenderText instead of duplicating the
code for Win and Linux.
(We do not have similar implementation in Mac though).

I will need to check why it fails in Windows.

+
+// static
+bool PrintWebViewHelper::ConvertTextToGlyphs(SkTypeface* typeface,
+                                             const string16& text,
+                                             std::vector<uint16_t>* glyphs) {
+  bool rtl = base::i18n::IsRTL() &&
+             base::i18n::StringContainsStrongRTLChars(text);
+  HRESULT hr = ScriptIsComplex(text.c_str(), text.size(), SIC_COMPLEX);
+  if (hr != S_OK && !rtl) {
+    return false;  // Script is neither complex nor BiDi.
+  }
+
+  // Complex script handling started here.
+  std::vector<SCRIPT_ITEM> items;
+  int max_items = text.size();
+  int generated_items;
+  for (;;) {
+    items.resize(max_items);
+    hr = ScriptItemize(text.c_str(), text.size(), max_items - 1, NULL, NULL,
+                       &items[0], &generated_items);
+    if (SUCCEEDED(hr)) {
+      items.resize(generated_items + 1);
+      break;
+    }
+    if (hr != E_OUTOFMEMORY) {
+      return false;
+    }
+    max_items *= 2;
+  }
+
+  std::vector<int> visual_to_logical(generated_items + 1);
+  std::vector<int> logical_to_visual(generated_items + 1);
+  std::vector<BYTE> directions(generated_items);
+  for (int i = 0; i < generated_items; ++i) {
+    directions[i] = items[i].a.s.uBidiLevel;
+  }
+
+  ScriptLayout(generated_items, &directions[0], &visual_to_logical[0],
+               &logical_to_visual[0]);
+  visual_to_logical.push_back(generated_items);
+  logical_to_visual.push_back(generated_items);
+
+  base::win::ScopedCreateDC dc(CreateCompatibleDC(GetDC(NULL)));
+  LOGFONT lf;
+  SkLOGFONTFromTypeface(typeface, &lf);
+  HFONT font_handle = CreateFontIndirect(&lf);
+  if (font_handle == NULL) {
+    return false;
+  }
+  SelectObject(dc.Get(), font_handle);
+
+  for (size_t i = 0; i < items.size() - 1; ++i) {
+    int index = logical_to_visual[i];
+    int input_length = items[index + 1].iCharPos - items[index].iCharPos;
+
+    // Initial size guess suggested by MSDN.
+    std::vector<WORD> logs(input_length);
+    int max_glyph_len = input_length * 3 / 2 + 16;
+    std::vector<WORD> glyph_buffer;
+    std::vector<SCRIPT_VISATTR> visattr;
+
+    for (;;) {
+      int glyphs_used;
+      glyph_buffer.resize(max_glyph_len);
+      visattr.resize(max_glyph_len);
+      items[index].a.fLogicalOrder = FALSE;
+      hr = ScriptShape(dc, &g_script_cache_, &text[items[index].iCharPos],
+                       input_length, max_glyph_len, &(items[index].a),
+                       &glyph_buffer[0], &logs[0], &visattr[0], &glyphs_used);
+      if (SUCCEEDED(hr)) {
+        // We are not supposed to handle Kashidas in Arabic, so reverting the
+        // glyph order shall be good enough for all RTLs.
+        glyph_buffer.resize(glyphs_used);
+        glyphs->insert(glyphs->end(), glyph_buffer.begin(),glyph_buffer.end());
+        break;
+      }
+
+      if (hr == E_PENDING) {
+        // keep waiting
+      } else if (hr != E_OUTOFMEMORY) {
+        return false;
+      }
+

[jungshik at Google, 2012/01/06 22:38:45]

After calling ScriptShape, ScriptPlace (?) has to be called as well. 

+      max_glyph_len *= 2;
+    }
+  }
+
+  return true;
+}
+#endif