Bug [#2027]. Implement font locale SCI_SETFONTLOCALE on Win32 using DirectWrite.

11 files changed, 71 insertions, 9 deletions

diff --git a/doc/ScintillaDoc.html b/doc/ScintillaDoc.html
index f3b26b88f..0443c7a24 100644
--- a/doc/ScintillaDoc.html
+++ b/doc/ScintillaDoc.html
@@ -120,7 +120,7 @@
 
     <h1>Scintilla Documentation</h1>
 
-    <p>Last edited 9 April 2021 NH</p>
+    <p>Last edited 20 April 2021 NH</p>
 
     <p style="background:#90F0C0">Scintilla 5 has moved the lexers from Scintilla into a new
     <a href="Lexilla.html">Lexilla</a> project.<br />
@@ -2970,6 +2970,9 @@ struct Sci_TextToFind {
      <a class="message" href="#SCI_STYLESETHOTSPOT">SCI_STYLESETHOTSPOT(int style, bool
     hotspot)</a><br />
     <a class="message" href="#SCI_STYLEGETHOTSPOT">SCI_STYLEGETHOTSPOT(int style) &rarr; bool</a><br />
+    <a class="message" href="#SCI_SETFONTLOCALE">SCI_SETFONTLOCALE(&lt;unused&gt;, const char
+    *fontName)</a><br />
+    <a class="message" href="#SCI_GETFONTLOCALE">SCI_GETFONTLOCALE(&lt;unused&gt;, char *fontName) &rarr; int</a><br />
     </code>
 
     <p><b id="SCI_STYLERESETDEFAULT">SCI_STYLERESETDEFAULT</b><br />
@@ -3298,6 +3301,15 @@ struct Sci_TextToFind {
        </tbody>
      </table>
 
+    <p><b id="SCI_SETFONTLOCALE">SCI_SETFONTLOCALE(&lt;unused&gt;, const char *localeName)</b><br />
+    <b id="SCI_GETFONTLOCALE">SCI_GETFONTLOCALE(&lt;unused&gt;, char *localeName NUL-terminated) &rarr; int</b><br />
+     These messages set the locale used for font selection with language-dependent glyphs.
+     It may, depending on platform and other circumstances influence the display of text, so setting "zh-Hant" may result in traditional
+     Chinese display and "zh-Hans" may result in simplified Chinese display.
+     It is currently only implemented for Win32 using DirectWrite where the value is passed as the localeName argument to CreateTextFormat.
+     The default value is US English "en-us".
+    </p>
+
     <h2 id="CaretAndSelectionStyles">Caret, selection, and hotspot styles</h2>
 
     <p>The selection is shown by changing the foreground and/or background colours. If one of these
@@ -4121,7 +4133,11 @@ struct Sci_TextToFind {
     <code>SC_TECHNOLOGY_DIRECTWRITEDC</code> differs from
     <code>SC_TECHNOLOGY_DIRECTWRITE</code> by using DirectWrite to draw into a GDI DC.
     Since Direct2D buffers drawing, Scintilla's buffering can be turned off with
-    <code>SCI_SETBUFFEREDDRAW(0)</code>.</p>
+    <code>SCI_SETBUFFEREDDRAW(0)</code>.
+    When using DirectWrite, you can use
+    <a class="message" href="#SCI_SETFONTLOCALE"><code>SCI_SETFONTLOCALE</code></a>
+    to set an appropriate font locale to draw text with expected language-dependent glyphs.
+    </p>
 
     <p><b id="SCI_SETFONTQUALITY">SCI_SETFONTQUALITY(int fontQuality)</b><br />
      <b id="SCI_GETFONTQUALITY">SCI_GETFONTQUALITY &rarr; int</b><br />
diff --git a/doc/ScintillaHistory.html b/doc/ScintillaHistory.html
index a63ac8fc3..5ced2dd86 100644
--- a/doc/ScintillaHistory.html
+++ b/doc/ScintillaHistory.html
@@ -582,6 +582,10 @@
 	On Windows, fix encoding used for text display with DirectWrite.
 	<a href="https://sourceforge.net/p/scintilla/bugs/2246/">Bug #2246</a>.
 	</li>
+	<li>
+	Implement font locale SCI_SETFONTLOCALE. Initially only for DirectWrite on Win32.
+	<a href="https://sourceforge.net/p/scintilla/bugs/2027/">Bug #2027</a>.
+	</li>
     </ul>
     <h3>
        <a href="https://www.scintilla.org/scintilla501.zip">Release 5.0.1</a>
diff --git a/include/Scintilla.h b/include/Scintilla.h
index 1ea5d3fa1..ca512ab71 100644
--- a/include/Scintilla.h
+++ b/include/Scintilla.h
@@ -103,6 +103,8 @@ typedef sptr_t (*SciFnDirect)(sptr_t ptr, unsigned int iMessage, uptr_t wParam,
 #define SCI_GETNEXTTABSTOP 2677
 #define SC_CP_UTF8 65001
 #define SCI_SETCODEPAGE 2037
+#define SCI_SETFONTLOCALE 2760
+#define SCI_GETFONTLOCALE 2761
 #define SC_IME_WINDOWED 0
 #define SC_IME_INLINE 1
 #define SCI_GETIMEINTERACTION 2678
diff --git a/include/Scintilla.iface b/include/Scintilla.iface
index 8cce965cc..946ba1ec8 100644
--- a/include/Scintilla.iface
+++ b/include/Scintilla.iface
@@ -282,6 +282,12 @@ val SC_CP_UTF8=65001
 # The SC_CP_UTF8 value can be used to enter Unicode mode.
 set void SetCodePage=2037(int codePage,)
 
+# Set the locale for displaying text.
+set void SetFontLocale=2760(, string localeName)
+
+# Set the locale for displaying text.
+set void GetFontLocale=2761(, stringresult localeName)
+
 enu IMEInteraction=SC_IME_
 val SC_IME_WINDOWED=0
 val SC_IME_INLINE=1
diff --git a/src/CallTip.cxx b/src/CallTip.cxx
index 22f559ef7..f9f3ce7f7 100644
--- a/src/CallTip.cxx
+++ b/src/CallTip.cxx
@@ -272,7 +272,9 @@ void CallTip::MouseClick(Point pt) noexcept {
 PRectangle CallTip::CallTipStart(Sci::Position pos, Point pt, int textHeight, const char *defn,
                                  const char *faceName, int size,
                                  int codePage_, int characterSet,
-								 int technology, const Window &wParent) {
+                                 int technology,
+                                 const char *localeName,
+                                 const Window &wParent) {
 	clickPlace = 0;
 	val = defn;
 	codePage = codePage_;
@@ -283,7 +285,8 @@ PRectangle CallTip::CallTipStart(Sci::Position pos, Point pt, int textHeight, co
 	inCallTipMode = true;
 	posStartCallTip = pos;
 	const XYPOSITION deviceHeight = static_cast<XYPOSITION>(surfaceMeasure->DeviceHeightFont(size));
-	const FontParameters fp(faceName, deviceHeight / SC_FONT_SIZE_MULTIPLIER, SC_WEIGHT_NORMAL, false, 0, technology, characterSet);
+	const FontParameters fp(faceName, deviceHeight / SC_FONT_SIZE_MULTIPLIER, SC_WEIGHT_NORMAL,
+		false, 0, technology, characterSet, localeName);
 	font = Font::Allocate(fp);
 	// Look for multiple lines in the text
 	// Only support \n here - simply means container must avoid \r!
diff --git a/src/CallTip.h b/src/CallTip.h
index 6cc89d3a5..f1358a94a 100644
--- a/src/CallTip.h
+++ b/src/CallTip.h
@@ -72,7 +72,8 @@ public:
 	/// Setup the calltip and return a rectangle of the area required.
 	PRectangle CallTipStart(Sci::Position pos, Point pt, int textHeight, const char *defn,
 		const char *faceName, int size, int codePage_,
-		int characterSet, int technology, const Window &wParent);
+		int characterSet, int technology, const char *localeName,
+		const Window &wParent);
 
 	void CallTipCancel();
 
diff --git a/src/Editor.cxx b/src/Editor.cxx
index 63ed979d9..208a075aa 100644
--- a/src/Editor.cxx
+++ b/src/Editor.cxx
@@ -7199,6 +7199,16 @@ sptr_t Editor::WndProc(unsigned int iMessage, uptr_t wParam, sptr_t lParam) {
 	case SCI_GETELEMENTALLOWSTRANSLUCENT:
 		return vs.ElementAllowsTranslucent(static_cast<int>(wParam));
 
+	case SCI_SETFONTLOCALE:
+		if (lParam) {
+			vs.SetFontLocaleName(CharPtrFromSPtr(lParam));
+			InvalidateStyleRedraw();
+		}
+		break;
+
+	case SCI_GETFONTLOCALE:
+		return StringResult(lParam, vs.localeName.c_str());
+
 #ifdef INCLUDE_DEPRECATED_FEATURES
 	case SCI_SETSTYLEBITS:
 		vs.EnsureStyle(0xff);
diff --git a/src/ScintillaBase.cxx b/src/ScintillaBase.cxx
index e2fb58206..72bb5f6e0 100644
--- a/src/ScintillaBase.cxx
+++ b/src/ScintillaBase.cxx
@@ -478,6 +478,7 @@ void ScintillaBase::CallTipShow(Point pt, const char *defn) {
 		CodePage(),
 		vs.styles[ctStyle].characterSet,
 		vs.technology,
+		vs.localeName.c_str(),
 		wMain);
 	// If the call-tip window would be out of the client
 	// space
diff --git a/src/ViewStyle.cxx b/src/ViewStyle.cxx
index f553f4205..aa6779728 100644
--- a/src/ViewStyle.cxx
+++ b/src/ViewStyle.cxx
@@ -42,14 +42,15 @@ FontRealised::FontRealised() noexcept = default;
 FontRealised::~FontRealised() {
 }
 
-void FontRealised::Realise(Surface &surface, int zoomLevel, int technology, const FontSpecification &fs) {
+void FontRealised::Realise(Surface &surface, int zoomLevel, int technology, const FontSpecification &fs, const char *localeName) {
 	PLATFORM_ASSERT(fs.fontName);
 	sizeZoomed = fs.size + zoomLevel * SC_FONT_SIZE_MULTIPLIER;
 	if (sizeZoomed <= 2 * SC_FONT_SIZE_MULTIPLIER)	// Hangs if sizeZoomed <= 1
 		sizeZoomed = 2 * SC_FONT_SIZE_MULTIPLIER;
 
 	const float deviceHeight = static_cast<float>(surface.DeviceHeightFont(sizeZoomed));
-	const FontParameters fp(fs.fontName, deviceHeight / SC_FONT_SIZE_MULTIPLIER, fs.weight, fs.italic, fs.extraFontFlag, technology, fs.characterSet);
+	const FontParameters fp(fs.fontName, deviceHeight / SC_FONT_SIZE_MULTIPLIER, fs.weight,
+		fs.italic, fs.extraFontFlag, technology, fs.characterSet, localeName);
 	font = Font::Allocate(fp);
 
 	ascent = static_cast<unsigned int>(surface.Ascent(font.get()));
@@ -152,6 +153,8 @@ ViewStyle::ViewStyle(const ViewStyle &source) : markers(MARKER_MAX + 1), indicat
 	wrapVisualFlagsLocation = source.wrapVisualFlagsLocation;
 	wrapVisualStartIndent = source.wrapVisualStartIndent;
 	wrapIndentMode = source.wrapIndentMode;
+
+	localeName = source.localeName;
 }
 
 ViewStyle::~ViewStyle() {
@@ -286,6 +289,8 @@ void ViewStyle::Init(size_t stylesSize_) {
 	wrapVisualFlagsLocation = 0;
 	wrapVisualStartIndent = 0;
 	wrapIndentMode = SC_WRAPINDENT_FIXED;
+
+	localeName = localeNameDefault;
 }
 
 void ViewStyle::Refresh(Surface &surface, int tabInChars) {
@@ -307,7 +312,7 @@ void ViewStyle::Refresh(Surface &surface, int tabInChars) {
 
 	// Ask platform to allocate each unique font.
 	for (std::pair<const FontSpecification, std::unique_ptr<FontRealised>> &font : fonts) {
-		font.second->Realise(surface, zoomLevel, technology, font.first);
+		font.second->Realise(surface, zoomLevel, technology, font.first, localeName.c_str());
 	}
 
 	// Set the platform font handle and measurements for each style.
@@ -400,6 +405,10 @@ void ViewStyle::SetStyleFontName(int styleIndex, const char *name) {
 	styles[styleIndex].fontName = fontNames.Save(name);
 }
 
+void ViewStyle::SetFontLocaleName(const char *name) {
+	localeName = name;
+}
+
 bool ViewStyle::ProtectionActive() const noexcept {
 	return someStylesProtected;
 }
diff --git a/src/ViewStyle.h b/src/ViewStyle.h
index 7f50804c2..946bd6c60 100644
--- a/src/ViewStyle.h
+++ b/src/ViewStyle.h
@@ -37,7 +37,7 @@ public:
 	FontRealised &operator=(const FontRealised &) = delete;
 	FontRealised &operator=(FontRealised &&) = delete;
 	virtual ~FontRealised();
-	void Realise(Surface &surface, int zoomLevel, int technology, const FontSpecification &fs);
+	void Realise(Surface &surface, int zoomLevel, int technology, const FontSpecification &fs, const char *localeName);
 };
 
 enum class IndentView {none, real, lookForward, lookBoth};
@@ -168,6 +168,8 @@ public:
 	int wrapVisualStartIndent;
 	int wrapIndentMode; // SC_WRAPINDENT_FIXED, _SAME, _INDENT
 
+	std::string localeName;
+
 	ViewStyle();
 	ViewStyle(const ViewStyle &source);
 	ViewStyle(ViewStyle &&) = delete;
@@ -184,6 +186,7 @@ public:
 	void ResetDefaultStyle();
 	void ClearStyles();
 	void SetStyleFontName(int styleIndex, const char *name);
+	void SetFontLocaleName(const char *name);
 	bool ProtectionActive() const noexcept;
 	int ExternalMarginWidth() const noexcept;
 	int MarginFromLocation(Point pt) const noexcept;
diff --git a/test/simpleTests.py b/test/simpleTests.py
index 89e2ff69c..63efc8019 100644
--- a/test/simpleTests.py
+++ b/test/simpleTests.py
@@ -1916,6 +1916,13 @@ class TestStyleAttributes(unittest.TestCase):
 		self.ed.SetDefaultFoldDisplayText(0, b"...")
 		self.assertEquals(self.ed.GetDefaultFoldDisplayText(), b"...")
 
+	def testFontLocale(self):
+		initialLocale = "en-us".encode("UTF-8")
+		testLocale = "zh-Hans".encode("UTF-8")
+		self.assertEquals(self.ed.GetFontLocale(), initialLocale)
+		self.ed.FontLocale = testLocale
+		self.assertEquals(self.ed.GetFontLocale(), testLocale)
+
 class TestIndices(unittest.TestCase):
 	def setUp(self):
 		self.xite = Xite.xiteFrame