Implement eliding/truncating at end in RenderText

ui/gfx/render_text_unittest.cc

Index: ui/gfx/render_text_unittest.cc
diff --git a/ui/gfx/render_text_unittest.cc b/ui/gfx/render_text_unittest.cc
index c8c50d428141cf2be2af4ae08c33b522a9befff6..e4c94977df1a136b538276daa50e0f237913aa90 100644
--- a/ui/gfx/render_text_unittest.cc
+++ b/ui/gfx/render_text_unittest.cc
@@ -401,6 +401,87 @@ TEST_F(RenderTextTest, RevealObscuredText) {
   EXPECT_EQ(valid_expect_5_and_6, render_text->GetLayoutText());
 }
 
+TEST_F(RenderTextTest, ElidedText) {
+  // TODO(skanuj) : Add more test cases for following
+  // - RenderText styles.
+  // - Cross interaction of truncate, elide and obscure.
+  // - ElideText tests from text_elider.cc.
+  struct {
+    const wchar_t* text;
+    const wchar_t* layout_text;
+  } cases[] = {
+    // Strings shorter than the elision width should be laid out in full.
+    { L""        , L""        },
+    { kWeak      , kWeak      },
+    { kLtr       , kLtr       },
+    { kLtrRtl    , kLtrRtl    },
+    { kLtrRtlLtr , kLtrRtlLtr },
+    { kRtl       , kRtl       },
+    { kRtlLtr    , kRtlLtr    },
+    { kRtlLtrRtl , kRtlLtrRtl },
+    // Strings as long as the elision width should be laid out in full.
+    { L"012ab",   L"012ab"   },
+    // Long strings should be elided with an ellipsis appended at the end.
+    { L"012" L"abc"                  , L"012a\x2026"               },
+    { L"012" L"ab" L"\x5d0\x5d1"     , L"012a\x2026"               },
+    { L"012" L"a" L"\x5d1" L"b"      , L"012a\x2026"               },
+    // No RLM marker added as digits (012) have weak directionality.
+    { L"01" L"\x5d0\x5d1\x5d2" L"ab" , L"01\x5d0\x5d1\x2026"       },
+    // RLM marker added as "ab" have string LTR directionality.

[msw, 2013/12/14 03:11:41]

nice, good comments!

[Anuj, 2013/12/14 03:35:03]

Fixed spelling of "strong" :)

+    { L"ab" L"\x5d0\x5d1\x5d2" L"ab" , L"ab\x5d0\x5d1\x2026\x200f" },
+    // Complex script is not handled. In this example, the "\x0915\x093f" is a
+    // compound glyph, but only half of it is elided.
+    { L"0123\x0915\x093f" L"abcd"          , L"0123\x0915\x2026"          },
+    // Surrogate pairs should be elided reasonably enough.
+    { L"0\x05e9\x05bc\x05c1\x05b8"         , L"0\x05e9\x05bc\x05c1\x05b8" },
+    { L"0\x05e9\x05bc\x05c1\x05b8" L"ab"   , L"0\x05e9\x05bc\x2026"       },
+    { L"01\x05e9\x05bc\x05c1\x05b8" L"ab"  , L"01\x05e9\x2026"            },
+    { L"012\x05e9\x05bc\x05c1\x05b8" L"ab" , L"012\x2026"                 },
+    { L"012\xF0\x9D\x84\x9E"               , L"012\xF0\x2026"             },
+  };
+
+  scoped_ptr<RenderText> expected_render_text(RenderText::CreateInstance());
+  expected_render_text->SetFontList(FontList("serif, Sans serif, 12px"));
+  expected_render_text->SetDisplayRect(gfx::Rect(0, 0, 9999, 100));
+
+  scoped_ptr<RenderText> render_text(RenderText::CreateInstance());
+  render_text->SetFontList(FontList("serif, Sans serif, 12px"));
+  render_text->SetElideBehavior(gfx::ELIDE_AT_END);
+  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); i++) {
+    expected_render_text->SetText(WideToUTF16(cases[i].layout_text));
+    int expected_width = expected_render_text->GetContentWidth();
+    render_text->SetText(WideToUTF16(cases[i].text));
+#if defined(OS_WIN)
+    int original_width = render_text->GetContentWidth();

[msw, 2013/12/14 03:11:41]

optional nit: you can inline this in the check below.

[Anuj, 2013/12/14 03:35:03]

I will let this be.

+    if ((base::win::GetVersion() < base::win::VERSION_VISTA) &&
+        (expected_width >= original_width))

[msw, 2013/12/14 03:11:41]

Ha! Was this the issue? the ellipsis character was wider than the text being
elided? Could this be corrected by adding more characters to the end of the
original string, so that the ellipsis is needed regardless, and the intended
codepoints will actually be elided? You don't *need* to fix this now, but I
would recommend it, since I could foresee the same issue recurring on other
platforms/versions/fonts. At least add a TODO comment about what's going on and
how it might be fixed.

[Anuj, 2013/12/14 03:35:03]

I am guessing so. Added the TODO.

+      continue;
+#endif
+    render_text->SetDisplayRect(gfx::Rect(0, 0, expected_width, 100));
+    EXPECT_EQ(WideToUTF16(cases[i].text), render_text->text());
+    EXPECT_EQ(WideToUTF16(cases[i].layout_text), render_text->GetLayoutText())
+        << "->For case " << i << ": " << cases[i].text << "\n";
+    expected_render_text->SetText(base::string16());
+  }
+}
+
+TEST_F(RenderTextTest, ElidedObscuredText) {
+  scoped_ptr<RenderText> expected_render_text(RenderText::CreateInstance());
+  expected_render_text->SetFontList(FontList("serif, Sans serif, 12px"));
+  expected_render_text->SetDisplayRect(gfx::Rect(0, 0, 9999, 100));
+  expected_render_text->SetText(WideToUTF16(L"**\x2026"));
+
+  scoped_ptr<RenderText> render_text(RenderText::CreateInstance());
+  render_text->SetFontList(FontList("serif, Sans serif, 12px"));
+  render_text->SetElideBehavior(gfx::ELIDE_AT_END);
+  render_text->SetDisplayRect(
+      gfx::Rect(0, 0, expected_render_text->GetContentWidth(), 100));
+  render_text->SetObscured(true);
+  render_text->SetText(WideToUTF16(L"abcdef"));
+  EXPECT_EQ(WideToUTF16(L"abcdef"), render_text->text());
+  EXPECT_EQ(WideToUTF16(L"**\x2026"), render_text->GetLayoutText());
+}
+
 TEST_F(RenderTextTest, TruncatedText) {
   struct {
     const wchar_t* text;