views: Support longer tooltips.

ui/views/corewm/tooltip_aura_unittest.cc

Index: ui/views/corewm/tooltip_aura_unittest.cc
diff --git a/ui/views/corewm/tooltip_aura_unittest.cc b/ui/views/corewm/tooltip_aura_unittest.cc
index 1e8981ad79191329c56dccad7d0d6383c9e2b977..df7682a34ec56a8f51ef737b8fa4c0376d2c2438 100644
--- a/ui/views/corewm/tooltip_aura_unittest.cc
+++ b/ui/views/corewm/tooltip_aura_unittest.cc
@@ -4,128 +4,158 @@
 
 #include "ui/views/corewm/tooltip_aura.h"
 
+#include "base/strings/string_split.h"
 #include "base/strings/utf_string_conversions.h"
 #include "ui/aura/test/aura_test_base.h"
-#include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/font_list.h"
 #include "ui/gfx/text_elider.h"
 #include "ui/gfx/text_utils.h"
 
-using base::ASCIIToUTF16;
-using base::UTF8ToUTF16;
-
 namespace views {
 namespace corewm {
 
+namespace {
+
+// Generates a string consisting of repeated copies of |word| separated by
+// |separator|. The string will be long enough to fill |num_lines| lines wrapped
+// at |max_width| pixels.
+base::string16 FillLines(const base::string16& word,
+                         const base::string16& separator,
+                         int max_width,
+                         int num_lines,
+                         const gfx::FontList& font_list) {
+  base::string16 text;
+  for (int lines = 0; lines < num_lines; ++lines) {
+    base::string16 line = word;
+    while (gfx::GetStringWidth(line + separator + word, font_list) <= max_width)
+      line += separator + word;
+
+    if (lines != 0)
+      text += separator;
+    text += line;
+  }
+  return text;
+}
+
+}  // namespace
+
 typedef aura::test::AuraTestBase TooltipAuraTest;
 
-TEST_F(TooltipAuraTest, TrimTooltipToFitTests) {
-  const gfx::FontList font_list;
-  const int max_width = 4000;
-  base::string16 tooltip;
-  int width, line_count, expect_lines;
-  int max_pixel_width = 400;  // copied from constants in tooltip_controller.cc
-  int max_lines = 10;  // copied from constants in tooltip_controller.cc
-  size_t tooltip_len;
-
-  // Error in computed size vs. expected size should not be greater than the
-  // size of the longest word.
-  int error_in_pixel_width = gfx::GetStringWidth(ASCIIToUTF16("tooltip"),
-                                                 font_list);
-
-  // Long tooltips should wrap to next line
-  tooltip.clear();
-  width = line_count = -1;
-  expect_lines = 3;
-  for (; gfx::GetStringWidth(tooltip, font_list) <=
-           (expect_lines - 1) * max_pixel_width;)
-    tooltip.append(ASCIIToUTF16("This is part of the tooltip"));
-  tooltip_len = tooltip.length();
-  TooltipAura::TrimTooltipToFit(font_list, max_width, &tooltip, &width,
+TEST_F(TooltipAuraTest, TrimTooltipToFit) {
+  const gfx::FontList kFontList;
+  const gfx::Size kMaxSize(2000, 1500);
+  const base::string16 kWord = base::ASCIIToUTF16("word");
+  const base::string16 kSpace = base::ASCIIToUTF16(" ");
+  const base::string16 kNewline = base::ASCIIToUTF16("\n");
+
+  // Long tooltips should wrap to the next line.
+  base::string16 text = FillLines(kWord, kSpace,
+      TooltipAura::kPreferredWidthPixels, 1, kFontList);
+  text += kSpace + kWord;
+  // The last space should be replaced by a newline.
+  base::string16 expected_text = text;
+  expected_text[expected_text.find_last_of(L' ')] = L'\n';
+  int width = 0, line_count = 0;
+  TooltipAura::TrimTooltipToFit(kFontList, kMaxSize, &text, &width,
                                 &line_count);
-  EXPECT_NEAR(max_pixel_width, width, error_in_pixel_width);
-  EXPECT_EQ(expect_lines, line_count);
-  EXPECT_EQ(tooltip_len + expect_lines - 1, tooltip.length());
-
-  // More than |max_lines| lines should get truncated at 10 lines.
-  tooltip.clear();
-  width = line_count = -1;
-  expect_lines = 13;
-  for (; gfx::GetStringWidth(tooltip, font_list) <=
-           (expect_lines - 1) * max_pixel_width;)
-    tooltip.append(ASCIIToUTF16("This is part of the tooltip"));
-  TooltipAura::TrimTooltipToFit(font_list, max_width, &tooltip, &width,
+  EXPECT_LE(width, TooltipAura::kPreferredWidthPixels);
+  EXPECT_EQ(2, line_count);
+  EXPECT_EQ(expected_text, text);
+
+  // The tooltip should be truncated to the number of lines that fit in the
+  // passed-in maximum size.
+  int max_lines = kMaxSize.height() / kFontList.GetHeight();
+  text = FillLines(
+      kWord, kSpace, TooltipAura::kPreferredWidthPixels, max_lines, kFontList);
+  text += kSpace + kWord;
+  size_t orig_length = text.size();
+  TooltipAura::TrimTooltipToFit(kFontList, kMaxSize, &text, &width,
                                 &line_count);
-  EXPECT_NEAR(max_pixel_width, width, error_in_pixel_width);
+  EXPECT_LE(width, TooltipAura::kPreferredWidthPixels);
   EXPECT_EQ(max_lines, line_count);
+  EXPECT_LT(text.size(), orig_length);
+
+  // When the original string contains two long lines, each line should be
+  // wrapped individually.
+  base::string16 line = FillLines(
+      kWord, kSpace, TooltipAura::kPreferredWidthPixels, 1, kFontList);
+  text = line + kSpace + kWord + kNewline + line + kSpace + kWord;
+  orig_length = text.size();
+  TooltipAura::TrimTooltipToFit(kFontList, kMaxSize, &text, &width,
+                                &line_count);
+  EXPECT_LE(width, TooltipAura::kPreferredWidthPixels);
+  EXPECT_EQ(4, line_count);
+  std::vector<base::string16> lines;
+  base::SplitString(text, L'\n', &lines);
+  ASSERT_EQ(4U, lines.size());
+  EXPECT_EQ(line, lines[0]);
+  EXPECT_EQ(kWord, lines[1]);
+  EXPECT_EQ(line, lines[2]);
+  EXPECT_EQ(kWord, lines[3]);
 
-  // Long multi line tooltips should wrap individual lines.
-  tooltip.clear();
-  width = line_count = -1;
-  expect_lines = 4;
-  for (; gfx::GetStringWidth(tooltip, font_list) <=
-           (expect_lines - 2) * max_pixel_width;)
-    tooltip.append(ASCIIToUTF16("This is part of the tooltip"));
-  tooltip.insert(tooltip.length() / 2, ASCIIToUTF16("\n"));
-  tooltip_len = tooltip.length();
-  TooltipAura::TrimTooltipToFit(font_list, max_width, &tooltip, &width,
+  // The preferred width should be exceeded if there's a long word.
+  text = FillLines(kWord, base::string16(),
+      TooltipAura::kPreferredWidthPixels, 1, kFontList);
+  text += kWord;
+  expected_text = text;
+  TooltipAura::TrimTooltipToFit(kFontList, kMaxSize, &text, &width,
                                 &line_count);
-  EXPECT_NEAR(max_pixel_width, width, error_in_pixel_width);
-  EXPECT_EQ(expect_lines, line_count);
-  // We may have inserted the line break above near a space which will get
-  // trimmed. Hence we may be off by 1 in the final tooltip length calculation.
-  EXPECT_NEAR(tooltip_len + expect_lines - 2, tooltip.length(), 1);
-
-#if !defined(OS_WIN)
-  // Tooltip with really long word gets elided.
-  tooltip.clear();
-  width = line_count = -1;
-  tooltip = UTF8ToUTF16(std::string('a', max_pixel_width));
-  TooltipAura::TrimTooltipToFit(font_list, max_width, &tooltip, &width,
+  EXPECT_GT(width, TooltipAura::kPreferredWidthPixels);
+  EXPECT_LT(width, kMaxSize.width());
+  EXPECT_EQ(1, line_count);
+  EXPECT_EQ(expected_text, text);
+
+  // If a word exceeds the maximum width, it should be elided.
+  const base::string16 kLongWord =
+      FillLines(kWord, base::string16(), kMaxSize.width(), 1, kFontList) +
+      kWord;
+  text = kLongWord;
+  expected_text = gfx::ElideText(
+      text, kFontList, kMaxSize.width(), gfx::ELIDE_TAIL);
+  TooltipAura::TrimTooltipToFit(kFontList, kMaxSize, &text, &width,
                                 &line_count);
-  EXPECT_NEAR(max_pixel_width, width, 5);
+  EXPECT_GT(width, TooltipAura::kPreferredWidthPixels);
+  EXPECT_LE(width, kMaxSize.width());
   EXPECT_EQ(1, line_count);
-  EXPECT_EQ(gfx::ElideText(UTF8ToUTF16(std::string('a', max_pixel_width)),
-                           font_list, max_pixel_width, gfx::ELIDE_TAIL),
-            tooltip);
-#endif
-
-  // Normal small tooltip should stay as is.
-  tooltip.clear();
-  width = line_count = -1;
-  tooltip = ASCIIToUTF16("Small Tooltip");
-  TooltipAura::TrimTooltipToFit(font_list, max_width, &tooltip, &width,
+  EXPECT_EQ(expected_text, text);
+
+  // When a long word makes the tooltip wider than the preferred width,
+  // other lines should be wrapped at the new, longer size.
+  text = FillLines(kWord, kSpace, kMaxSize.width(), 1, kFontList);
+  text += kNewline + kLongWord;
+  text += kNewline + FillLines(kWord, kSpace, kMaxSize.width(), 1, kFontList);
+  TooltipAura::TrimTooltipToFit(kFontList, kMaxSize, &text, &width,
+                                &line_count);
+  EXPECT_GT(width, TooltipAura::kPreferredWidthPixels);
+  EXPECT_LE(width, kMaxSize.width());
+  EXPECT_EQ(3, line_count);
+
+  // A normal small tooltip should stay as is.
+  text = base::ASCIIToUTF16("Small Tooltip");
+  expected_text = text;
+  TooltipAura::TrimTooltipToFit(kFontList, kMaxSize, &text, &width,
                                 &line_count);
-  EXPECT_EQ(gfx::GetStringWidth(ASCIIToUTF16("Small Tooltip"), font_list),
-            width);
+  EXPECT_LE(width, TooltipAura::kPreferredWidthPixels);
   EXPECT_EQ(1, line_count);
-  EXPECT_EQ(ASCIIToUTF16("Small Tooltip"), tooltip);
+  EXPECT_EQ(expected_text, text);
 
-  // Normal small multi-line tooltip should stay as is.
-  tooltip.clear();
-  width = line_count = -1;
-  tooltip = ASCIIToUTF16("Multi line\nTooltip");
-  TooltipAura::TrimTooltipToFit(font_list, max_width, &tooltip, &width,
+  // A normal small multi-line tooltip should stay as is.
+  text = base::ASCIIToUTF16("Multi line\nTooltip");
+  expected_text = text;
+  TooltipAura::TrimTooltipToFit(kFontList, kMaxSize, &text, &width,
                                 &line_count);
-  int expected_width = gfx::GetStringWidth(ASCIIToUTF16("Multi line"),
-                                           font_list);
-  expected_width = std::max(expected_width,
-                            gfx::GetStringWidth(ASCIIToUTF16("Tooltip"),
-                                                font_list));
-  EXPECT_EQ(expected_width, width);
+  EXPECT_LE(width, TooltipAura::kPreferredWidthPixels);
   EXPECT_EQ(2, line_count);
-  EXPECT_EQ(ASCIIToUTF16("Multi line\nTooltip"), tooltip);
+  EXPECT_EQ(expected_text, text);
 
-  // Whitespaces in tooltips are preserved.
-  tooltip.clear();
-  width = line_count = -1;
-  tooltip = ASCIIToUTF16("Small  Tool  t\tip");
-  TooltipAura::TrimTooltipToFit(font_list, max_width, &tooltip, &width,
+  // Whitespace in the middle of tooltips should be preserved.
+  text = base::ASCIIToUTF16("Small  Tool  t\tip");
+  expected_text = text;
+  TooltipAura::TrimTooltipToFit(kFontList, kMaxSize, &text, &width,
                                 &line_count);
-  EXPECT_EQ(gfx::GetStringWidth(ASCIIToUTF16("Small  Tool  t\tip"), font_list),
-            width);
+  EXPECT_LE(width, TooltipAura::kPreferredWidthPixels);
   EXPECT_EQ(1, line_count);
-  EXPECT_EQ(ASCIIToUTF16("Small  Tool  t\tip"), tooltip);
+  EXPECT_EQ(expected_text, text);
 }
 
 }  // namespace corewm