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 ffa19174d28c18fa9a3b70e4a512778253a4d318..b06a04f21ba483cd1d234041ff8096d52b99b9af 100644
--- a/ui/gfx/render_text_unittest.cc
+++ b/ui/gfx/render_text_unittest.cc
@@ -400,6 +400,74 @@ TEST_F(RenderTextTest, RevealObscuredText) {
   EXPECT_EQ(valid_expect_5_and_6, render_text->GetLayoutText());
 }
 
+TEST_F(RenderTextTest, ElidedText) {

[msw, 2013/12/12 19:28:29]

I think this test might be too fragile with hard-coded exact pixel widths; we've
seen the available fonts change with test bot upgrades, variations between
platforms, etc. Could this test measure the width of the expected layout_text
and use those widths for the display rect?

[Anuj, 2013/12/13 01:23:50]

Done.

+  // TODO(skanuj) : Add more test cases, possibly covering styles.
+  // To add more test cases, add a new case with large expected width.
+  // Uncomment the log statements below and find the actual width for
+  // layout_text, and update the test case.
+  struct {
+    const wchar_t* text;
+    const wchar_t* layout_text;
+    const int width;
+  } cases[] = {
+    // Strings shorter than the elision width should be laid out in full.
+    { L"",        L""        , 30},

[msw, 2013/12/12 19:28:29]

nit: align the comments after the preceding entry:
{ L"",        L"",          30},

[Anuj, 2013/12/13 01:23:50]

Didn't understand.

[msw, 2013/12/13 01:56:08]

D'oh I meant "align the commas", so that the commas are after the strings, not
after some spaces and just one space before the pixel widths.

[Anuj, 2013/12/13 02:23:45]

Done.

+    { kWeak,      kWeak      , 30},
+    { kLtr,       kLtr       , 30},
+    { kLtrRtl,    kLtrRtl    , 30},
+    { kLtrRtlLtr, kLtrRtlLtr , 30},
+    { kRtl,       kRtl       , 30},
+    { kRtlLtr,    kRtlLtr    , 30},
+    { kRtlLtrRtl, kRtlLtrRtl , 30},
+    // Strings as long as the elision width should be laid out in full.
+    { L"012ab",   L"012ab"   , 40},
+    // Long strings should be elided with an ellipsis appended at the end.
+    { L"012" L"abc",              L"012a\x2026"     , 44},

[msw, 2013/12/12 19:28:29]

nit: align the strings within each commented section.

[Anuj, 2013/12/13 01:23:50]

For the record, I find this column formatting insane!!

[msw, 2013/12/13 01:56:08]

I think it makes reading test cases easier :)

[Anuj, 2013/12/13 02:23:45]

Looks like I have some motivation to hack on clang-format.

+    { L"012" L"ab" L"\x5d0\x5d1",  L"012a\x2026"    , 44},
+    { L"012" L"a" L"\x5d1" L"b",  L"012a\x2026"     , 44},
+    { L"01" L"\x5d0\x5d1\x5d2" L"ab",  L"01\x5d0\x5d1\x2026" , 37},
+    { L"ab" L"\x5d0\x5d1\x5d2" L"ab",  L"ab\x5d0\x5d1\x2026\x200f" , 39},
+    // Surrogate pairs should be elided reasonably enough.
+    { L"0123\x0915\x093f" L"abcd",      L"0123\x0915\x2026"          , 50},
+    { L"0\x05e9\x05bc\x05c1\x05b8",     L"0\x05e9\x05bc\x05c1\x05b8" , 14},
+    { L"0\x05e9\x05bc\x05c1\x05b8" L"ab",   L"0\x05e9\x05bc\x2026"   , 26},
+    { L"01\x05e9\x05bc\x05c1\x05b8" L"ab",   L"01\x05e9\x2026"       , 32},
+    { L"012\x05e9\x05bc\x05c1\x05b8" L"ab",  L"012\x2026"            , 37},
+    { L"012\xF0\x9D\x84\x9E",           L"012\xF0\x2026"             , 44},
+  };
+
+  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++) {
+    render_text->SetDisplayRect(gfx::Rect(0, 0, cases[i].width, 100));
+    render_text->SetText(WideToUTF16(cases[i].text));
+    EXPECT_EQ(WideToUTF16(cases[i].text), render_text->text());
+    EXPECT_LE(render_text->GetContentWidth(), cases[i].width)
+        << "->For case " << i << ": " << cases[i].text << "\n";
+    EXPECT_EQ(WideToUTF16(cases[i].layout_text), render_text->GetLayoutText())
+        << "->For case " << i << ": " << cases[i].text << "\n";
+    render_text->SetText(base::string16());

[msw, 2013/12/12 19:28:29]

Why is this needed?

[Anuj, 2013/12/13 01:23:50]

To clear the layout text.

+
+    // render_text->SetDisplayRect(gfx::Rect(0, 0, 9000, 100));
+    // render_text->SetText(WideToUTF16(cases[i].layout_text));
+    // LOG(ERROR) << "Expected ContentWidth:" << render_text->GetContentWidth()
+        // << " case: " << i << ": " << render_text->GetLayoutText();
+    // render_text->SetText(base::string16());
+  }
+}
+
+TEST_F(RenderTextTest, ElidedObscuredText) {
+  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, 30, 100));

[msw, 2013/12/12 19:28:29]

Ditto here, consider using the width of L"**\x2026" instead of hard-coded 30px.

[Anuj, 2013/12/13 01:23:50]

Done.

+  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;