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..74cd78d1f704c7323828fab167c2af80001f7b41 100644
--- a/ui/gfx/render_text_unittest.cc
+++ b/ui/gfx/render_text_unittest.cc
@@ -401,6 +401,91 @@ 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;
+    const bool elision_expected;
+  } cases[] = {
+    // Strings shorter than the elision width should be laid out in full.
+    { L"",        L""       , false },
+    { kWeak,      kWeak     , false },
+    { kLtr,       kLtr      , false },
+    { kLtrRtl,    kLtrRtl   , false },
+    { kLtrRtlLtr, kLtrRtlLtr, false },
+    { kRtl,       kRtl      , false },
+    { kRtlLtr,    kRtlLtr   , false },
+    { kRtlLtrRtl, kRtlLtrRtl, false },
+    // Strings as long as the elision width should be laid out in full.
+    { L"012ab",   L"012ab"  , false },
+    // Long strings should be elided with an ellipsis appended at the end.
+    { L"012abc",              L"012a\x2026", true },
+    { L"012ab" L"\x5d0\x5d1", L"012a\x2026", true },
+    { L"012a" L"\x5d1" L"b",  L"012a\x2026", true },
+    // No RLM marker added as digits (012) have weak directionality.
+    { L"01" L"\x5d0\x5d1\x5d2", L"01\x5d0\x5d1\x2026", true },
+    // RLM marker added as "ab" have strong LTR directionality.
+    { L"ab" L"\x5d0\x5d1\x5d2", L"ab\x5d0\x5d1\x2026\x200f", true },
+    // 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"0123\x0915\x2026", true },
+    // Surrogate pairs should be elided reasonably enough.
+    { L"0\x05e9\x05bc\x05c1\x05b8",   L"0\x05e9\x05bc\x05c1\x05b8", false },
+    { L"0\x05e9\x05bc\x05c1\x05b8",   L"0\x05e9\x05bc\x2026"      , true  },
+    { L"01\x05e9\x05bc\x05c1\x05b8",  L"01\x05e9\x2026"           , true  },
+    { L"012\x05e9\x05bc\x05c1\x05b8", L"012\x2026"                , true  },
+    { L"012\xF0\x9D\x84\x9E",         L"012\xF0\x2026"            , true  },
+  };
+
+  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++) {
+    // Compute expected width
+    expected_render_text->SetText(WideToUTF16(cases[i].layout_text));
+    int expected_width = expected_render_text->GetContentWidth();
+
+    base::string16 input = WideToUTF16(cases[i].text);
+    // Extend the text of testcase to ensure that it is wider than the

[msw, 2013/12/30 23:18:00]

nit: s/text of testcase/input text/

[Anuj, 2013/12/31 00:04:03]

Done.

+    // layout_text, and so it will get elided.
+    if (cases[i].elision_expected)
+      input.append(WideToUTF16(L" MMMMMMMMMMM"));
+
+    render_text->SetText(input);
+    render_text->SetDisplayRect(gfx::Rect(0, 0, expected_width, 100));
+    EXPECT_EQ(input, 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;