aura: Really long tooltips should be wrapped not truncated.

ash/tooltips/tooltip_controller_unittest.cc

Index: ash/tooltips/tooltip_controller_unittest.cc
diff --git a/ash/tooltips/tooltip_controller_unittest.cc b/ash/tooltips/tooltip_controller_unittest.cc
index f07dfd559b7926c9bf87cf4490835681d5603901..044432613e9a9e9bf30ccd4fbfad8ca1878be852 100644
--- a/ash/tooltips/tooltip_controller_unittest.cc
+++ b/ash/tooltips/tooltip_controller_unittest.cc
@@ -10,6 +10,9 @@
 #include "ui/aura/root_window.h"
 #include "ui/aura/test/event_generator.h"
 #include "ui/aura/window.h"
+#include "ui/base/resource/resource_bundle.h"
+#include "ui/base/text/text_elider.h"
+#include "ui/gfx/font.h"
 #include "ui/gfx/point.h"
 #include "ui/views/view.h"
 #include "ui/views/widget/widget.h"
@@ -71,6 +74,11 @@ ash::internal::TooltipController* GetController() {
       aura::client::GetTooltipClient(Shell::GetRootWindow()));
 }
 
+gfx::Font GetDefaultFont() {
+  return ui::ResourceBundle::GetSharedInstance().GetFont(
+      ui::ResourceBundle::BaseFont);
+}
+
 }  // namespace
 
 class TooltipControllerTest : public AshTestBase {
@@ -94,6 +102,15 @@ class TooltipControllerTest : public AshTestBase {
     return GetController()->IsTooltipVisible();
   }
 
+  void TrimTooltipToFit(string16* text,
+                        int* max_width,
+                        int* line_count,
+                        int x,
+                        int y) {
+    ash::internal::TooltipController::TrimTooltipToFit(text, max_width,
+        line_count, x, y);
+  }
+
  private:
   DISALLOW_COPY_AND_ASSIGN(TooltipControllerTest);
 };
@@ -208,5 +225,95 @@ TEST_F(TooltipControllerTest, EnableOrDisableTooltips) {
   EXPECT_TRUE(IsTooltipVisible());
 }
 
+TEST_F(TooltipControllerTest, TrimTooltipToFitTests) {
+  string16 tooltip;
+  int max_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
+  gfx::Font font = GetDefaultFont();
+  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 = font.GetStringWidth(ASCIIToUTF16("tooltip"));
+
+  // Long tooltips should wrap to next line
+  tooltip.clear();
+  max_width = line_count = -1;
+  expect_lines = 3;
+  for (; font.GetStringWidth(tooltip) <= (expect_lines - 1) * max_pixel_width;)
+    tooltip.append(ASCIIToUTF16("This is part of the tooltip"));
+  tooltip_len = tooltip.length();
+  TrimTooltipToFit(&tooltip, &max_width, &line_count, 0, 0);
+  EXPECT_NEAR(max_pixel_width, max_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();
+  max_width = line_count = -1;
+  expect_lines = 13;
+  for (; font.GetStringWidth(tooltip) <= (expect_lines - 1) * max_pixel_width;)
+    tooltip.append(ASCIIToUTF16("This is part of the tooltip"));
+  TrimTooltipToFit(&tooltip, &max_width, &line_count, 0, 0);
+  EXPECT_NEAR(max_pixel_width, max_width, error_in_pixel_width);
+  EXPECT_EQ(max_lines, line_count);
+
+  // Long multi line tooltips should wrap individual lines.
+  tooltip.clear();
+  max_width = line_count = -1;
+  expect_lines = 4;
+  for (; font.GetStringWidth(tooltip) <= (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();
+  TrimTooltipToFit(&tooltip, &max_width, &line_count, 0, 0);
+  EXPECT_NEAR(max_pixel_width, max_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);
+
+  // Tooltip with really long word gets elided.
+  tooltip.clear();
+  max_width = line_count = -1;
+  tooltip = UTF8ToUTF16(std::string('a', max_pixel_width));
+  TrimTooltipToFit(&tooltip, &max_width, &line_count, 0, 0);
+  EXPECT_NEAR(max_pixel_width, max_width, 5);
+  EXPECT_EQ(1, line_count);
+  EXPECT_EQ(ui::ElideText(UTF8ToUTF16(std::string('a', max_pixel_width)), font,
+                          max_pixel_width, ui::ELIDE_AT_END), tooltip);
+
+  // Normal small tooltip should stay as is.
+  tooltip.clear();
+  max_width = line_count = -1;
+  tooltip = ASCIIToUTF16("Small Tooltip");
+  TrimTooltipToFit(&tooltip, &max_width, &line_count, 0, 0);
+  EXPECT_EQ(font.GetStringWidth(ASCIIToUTF16("Small Tooltip")), max_width);
+  EXPECT_EQ(1, line_count);
+  EXPECT_EQ(ASCIIToUTF16("Small Tooltip"), tooltip);
+
+  // Normal small multi-line tooltip should stay as is.
+  tooltip.clear();
+  max_width = line_count = -1;
+  tooltip = ASCIIToUTF16("Multi line\nTooltip");
+  TrimTooltipToFit(&tooltip, &max_width, &line_count, 0, 0);
+  int expected_width = font.GetStringWidth(ASCIIToUTF16("Multi line"));
+  expected_width = std::max(expected_width,
+                            font.GetStringWidth(ASCIIToUTF16("Tooltip")));
+  EXPECT_EQ(expected_width, max_width);
+  EXPECT_EQ(2, line_count);
+  EXPECT_EQ(ASCIIToUTF16("Multi line\nTooltip"), tooltip);
+
+  // Whitespaces in tooltips are preserved.
+  tooltip.clear();
+  max_width = line_count = -1;
+  tooltip = ASCIIToUTF16("Small  Tool  t\tip");
+  TrimTooltipToFit(&tooltip, &max_width, &line_count, 0, 0);
+  EXPECT_EQ(font.GetStringWidth(ASCIIToUTF16("Small  Tool  t\tip")), max_width);
+  EXPECT_EQ(1, line_count);
+  EXPECT_EQ(ASCIIToUTF16("Small  Tool  t\tip"), tooltip);
+}
+
 }  // namespace test
 }  // namespace ash