Forcing font size to be >= IDS_MINIMUM_UI_FONT_SIZE (usually 5, but for some

locales more than that).Fixed spelling in font.h.Added windows only unittest for
it.

BUG=2919 (http://crbug.com/2919)
TEST=Pass font_unittest on Windows
Patch by cira 
Original Review: http://codereview.chromium.org/125159


git-svn-id: svn://svn.chromium.org/chrome/trunk/src@18552 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 51 insertions, 19 deletions

diff --git a/app/gfx/font.h b/app/gfx/font.h
index bf759f75..ef03d99 100644
--- a/app/gfx/font.h
+++ b/app/gfx/font.h
@@ -65,7 +65,7 @@ class Font {
   }
 
   // Returns a new Font derived from the existing font.
-  // size_deta is the size to add to the current font. See the single
+  // size_delta is the size to add to the current font. See the single
   // argument version of this method for an example.
   // The style parameter specifies the new style for the font, and is a
   // bitmask of the values: BOLD, ITALIC and UNDERLINED.
diff --git a/app/gfx/font_unittest.cc b/app/gfx/font_unittest.cc
index 3a13e2f6..dc81ca8 100644
--- a/app/gfx/font_unittest.cc
+++ b/app/gfx/font_unittest.cc
@@ -56,4 +56,23 @@ TEST_F(FontTest, Widths) {
   ASSERT_GT(cf.GetStringWidth(L"abc"), cf.GetStringWidth(L"ab"));
 }
 
+#if defined(OS_WIN)
+TEST_F(FontTest, DeriveFontResizesIfSizeTooSmall) {
+  // This creates font of height -8.
+  Font cf(Font::CreateFont(L"Arial", 6));
+  Font derived_font = cf.DeriveFont(-4);
+  LOGFONT font_info;
+  GetObject(derived_font.hfont(), sizeof(LOGFONT), &font_info);
+  EXPECT_EQ(-5, font_info.lfHeight);
+}
+
+TEST_F(FontTest, DeriveFontKeepsOriginalSizeIfHeightOk) {
+  // This creates font of height -8.
+  Font cf(Font::CreateFont(L"Arial", 6));
+  Font derived_font = cf.DeriveFont(-2);
+  LOGFONT font_info;
+  GetObject(derived_font.hfont(), sizeof(LOGFONT), &font_info);
+  EXPECT_EQ(-6, font_info.lfHeight);
+}
+#endif
 }  // anonymous namespace
diff --git a/app/gfx/font_win.cc b/app/gfx/font_win.cc
index c1b9d24..5e22efe 100644
--- a/app/gfx/font_win.cc
+++ b/app/gfx/font_win.cc
@@ -9,9 +9,12 @@
 
 #include <algorithm>
 
+#include "app/l10n_util.h"
 #include "app/l10n_util_win.h"
 #include "base/logging.h"
+#include "base/string_util.h"
 #include "base/win_util.h"
+#include "grit/app_locale_settings.h"
 
 namespace gfx {
 
@@ -22,6 +25,25 @@ Font::HFontRef* Font::base_font_ref_;
 // font is bold.
 static const int kTextMetricWeightBold = 700;
 
+// Returns either minimum font allowed for a current locale or
+// lf_height + size_delta value.
+static int AdjustFontSize(int lf_height, int size_delta) {
+  if (lf_height < 0) {
+    lf_height -= size_delta;
+  } else {
+    lf_height += size_delta;
+  }
+  int min_font_size =
+    StringToInt(l10n_util::GetString(IDS_MINIMUM_UI_FONT_SIZE).c_str());
+  // Make sure lf_height is not smaller than allowed min font size for current
+  // locale.
+  if (abs(lf_height) < min_font_size) {
+    return lf_height < 0 ? -min_font_size : min_font_size;
+  } else {
+    return lf_height;
+  }
+}
+
 //
 // Font
 //
@@ -78,12 +100,8 @@ Font::HFontRef* Font::GetBaseFontRef() {
     win_util::GetNonClientMetrics(&metrics);
 
     l10n_util::AdjustUIFont(&metrics.lfMessageFont);
-
-    // See comment in Font::DeriveFont() about font size.
-    // TODO(jungshik): Add a per-locale resource entry for the minimum
-    // font size  and actually enforce the lower-bound. 5 is way too small
-    // for CJK, Thai, and Indian locales.
-    DCHECK_GE(abs(metrics.lfMessageFont.lfHeight), 5);
+    metrics.lfMessageFont.lfHeight =
+        AdjustFontSize(metrics.lfMessageFont.lfHeight, 0);
     HFONT font = CreateFontIndirect(&metrics.lfMessageFont);
     DLOG_ASSERT(font);
     base_font_ref_ = Font::CreateHFontRef(font);
@@ -133,21 +151,10 @@ Font::HFontRef::~HFontRef() {
   DeleteObject(hfont_);
 }
 
-
 Font Font::DeriveFont(int size_delta, int style) const {
   LOGFONT font_info;
   GetObject(hfont(), sizeof(LOGFONT), &font_info);
-  // LOGFONT returns two types of font heights, negative is measured slightly
-  // differently (character height, vs cell height).
-  if (font_info.lfHeight < 0) {
-    font_info.lfHeight -= size_delta;
-  } else {
-    font_info.lfHeight += size_delta;
-  }
-  // Even with "Small Fonts", the smallest readable font size is 5. It is easy
-  // to create a non-drawing font and forget about the fact that text should be
-  // drawn in the UI. This test ensures that the font will be readable.
-  DCHECK_GE(abs(font_info.lfHeight), 5);
+  font_info.lfHeight = AdjustFontSize(font_info.lfHeight, size_delta);
   font_info.lfUnderline = ((style & UNDERLINED) == UNDERLINED);
   font_info.lfItalic = ((style & ITALIC) == ITALIC);
   font_info.lfWeight = (style & BOLD) ? FW_BOLD : FW_NORMAL;
diff --git a/app/resources/app_locale_settings.grd b/app/resources/app_locale_settings.grd
index c86e4dc..e004736 100644
--- a/app/resources/app_locale_settings.grd
+++ b/app/resources/app_locale_settings.grd
@@ -193,6 +193,12 @@
       <message name="IDS_UI_FONT_SIZE_SCALER_XP" use_name_for_id="true">
         100
       </message>
+      
+      <!-- Limit minimum UI font size to 5 for all locales.
+           TODO(cira): add exceptions once we create xtb files. -->
+      <message name="IDS_MINIMUM_UI_FONT_SIZE" use_name_for_id="true">
+        5
+      </message>
     </messages>
   </release>
 </grit>