Feature [feature-requests:#1453] Added SCI_STYLESETINVISIBLEREPRESENTATION to

make it easier to edit around invisible text.
This also allows representing long lexemes with a single character to provide a
summarized view.

12 files changed, 94 insertions, 1 deletions

diff --git a/call/ScintillaCall.cxx b/call/ScintillaCall.cxx
index 1f496c53d..434e3fdf0 100644
--- a/call/ScintillaCall.cxx
+++ b/call/ScintillaCall.cxx
@@ -647,6 +647,18 @@ bool ScintillaCall::StyleGetCheckMonospaced(int style) {
 	return Call(Message::StyleGetCheckMonospaced, style);
 }
 
+void ScintillaCall::StyleSetInvisibleRepresentation(int style, const char *representation) {
+	CallString(Message::StyleSetInvisibleRepresentation, style, representation);
+}
+
+int ScintillaCall::StyleGetInvisibleRepresentation(int style, char *representation) {
+	return static_cast<int>(CallPointer(Message::StyleGetInvisibleRepresentation, style, representation));
+}
+
+std::string ScintillaCall::StyleGetInvisibleRepresentation(int style) {
+	return CallReturnString(Message::StyleGetInvisibleRepresentation, style);
+}
+
 void ScintillaCall::SetElementColour(Scintilla::Element element, ColourAlpha colourElement) {
 	Call(Message::SetElementColour, static_cast<uintptr_t>(element), colourElement);
 }
diff --git a/doc/ScintillaDoc.html b/doc/ScintillaDoc.html
index a9a7e72ed..fb5d59dfd 100644
--- a/doc/ScintillaDoc.html
+++ b/doc/ScintillaDoc.html
@@ -3248,6 +3248,8 @@ struct Sci_TextToFindFull {
      <a class="message" href="#SCI_STYLESETCHECKMONOSPACED">SCI_STYLESETCHECKMONOSPACED(int style, bool
     checkMonospaced)</a><br />
     <a class="message" href="#SCI_STYLEGETCHECKMONOSPACED">SCI_STYLEGETCHECKMONOSPACED(int style) &rarr; bool</a><br />
+    <a class="message" href="#SCI_STYLESETINVISIBLEREPRESENTATION">SCI_STYLESETINVISIBLEREPRESENTATION(int style, const char *representation)</a><br />
+    <a class="message" href="#SCI_STYLEGETINVISIBLEREPRESENTATION">SCI_STYLEGETINVISIBLEREPRESENTATION(int style, char *representation NUL-terminated) &rarr; int</a><br />
     <a class="message" href="#SCI_SETFONTLOCALE">SCI_SETFONTLOCALE(&lt;unused&gt;, const char *localeName)</a><br />
     <a class="message" href="#SCI_GETFONTLOCALE">SCI_GETFONTLOCALE(&lt;unused&gt;, char *localeName) &rarr; int</a><br />
     </code>
@@ -3514,6 +3516,15 @@ struct Sci_TextToFindFull {
     Applications may apply the 'check monospaced' attribute just to fonts known to be monospaced or on all fonts, leaving it to Scintilla to
     reject fonts that are proportional.</p>
 
+    <p><b id="SCI_STYLESETINVISIBLEREPRESENTATION">SCI_STYLESETINVISIBLEREPRESENTATION(int style, const char *representation)</b><br />
+    <b id="SCI_STYLEGETINVISIBLEREPRESENTATION">SCI_STYLEGETINVISIBLEREPRESENTATION(int style, char *representation NUL-terminated) &rarr; int</b><br />
+     When a style is made invisible with <a class="seealso" href="#SCI_STYLESETVISIBLE">SCI_STYLESETVISIBLE</a>, text is difficult to edit as
+     the cursor can be at both sides of the invisible text segment. With these messages invisible text segements can be made visible with a single
+     UTF8 characater giving the user an indication if the cursor is left or right of the invisible text. The character is displayed using the current style.</p>
+
+    <p>The <code>representation</code> parameter is a zero terminated string holding the one character used to represent the invisible text segment. Only the first character
+    is used, the character is decoded as UTF-8.</p>
+
     <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.
diff --git a/doc/ScintillaHistory.html b/doc/ScintillaHistory.html
index abbf4f4ef..cac690226 100644
--- a/doc/ScintillaHistory.html
+++ b/doc/ScintillaHistory.html
@@ -573,6 +573,7 @@
 	<td>Jacky Yang</td>
       </tr><tr>
 	<td>Reinhard Nißl</td>
+	<td>Ferdinand Oeinck</td>
     </tr>
     </table>
     <h2>Releases</h2>
@@ -584,6 +585,11 @@
 	Released 27 August 2022.
 	</li>
 	<li>
+	Added SCI_STYLESETINVISIBLEREPRESENTATION to make it easier to edit around invisible text.
+	This also allows representing long lexemes with a single character to provide a summarized view.
+	<a href="https://sourceforge.net/p/scintilla/feature-requests/1453/">Feature #1453</a>.
+	</li>
+	<li>
 	Removed NotifyLexerChanged notification from DocWatcher.
 	This is a private interface but could be used by independent platform layers
 	and was exposed by ScintillaDocument in the Qt implementation of ScintillaEdit.
diff --git a/include/Scintilla.h b/include/Scintilla.h
index 5781674e3..03302e293 100644
--- a/include/Scintilla.h
+++ b/include/Scintilla.h
@@ -280,6 +280,8 @@ typedef sptr_t (*SciFnDirectStatus)(sptr_t ptr, unsigned int iMessage, uptr_t wP
 #define SCI_STYLESETHOTSPOT 2409
 #define SCI_STYLESETCHECKMONOSPACED 2254
 #define SCI_STYLEGETCHECKMONOSPACED 2255
+#define SCI_STYLESETINVISIBLEREPRESENTATION 2256
+#define SCI_STYLEGETINVISIBLEREPRESENTATION 2257
 #define SC_ELEMENT_LIST 0
 #define SC_ELEMENT_LIST_BACK 1
 #define SC_ELEMENT_LIST_SELECTED 2
diff --git a/include/Scintilla.iface b/include/Scintilla.iface
index bd6cb76de..b03b8c8ca 100644
--- a/include/Scintilla.iface
+++ b/include/Scintilla.iface
@@ -694,6 +694,12 @@ set void StyleSetCheckMonospaced=2254(int style, bool checkMonospaced)
 # Get whether a style may be monospaced.
 get bool StyleGetCheckMonospaced=2255(int style,)
 
+# Set the invisible representation for a style.
+set void StyleSetInvisibleRepresentation=2256(int style, string representation)
+
+# Get the invisible representation for a style.
+get int StyleGetInvisibleRepresentation=2257(int style, stringresult representation)
+
 enu Element=SC_ELEMENT_
 val SC_ELEMENT_LIST=0
 val SC_ELEMENT_LIST_BACK=1
diff --git a/include/ScintillaCall.h b/include/ScintillaCall.h
index 0e79e37db..4b8e3c732 100644
--- a/include/ScintillaCall.h
+++ b/include/ScintillaCall.h
@@ -200,6 +200,9 @@ public:
 	void StyleSetHotSpot(int style, bool hotspot);
 	void StyleSetCheckMonospaced(int style, bool checkMonospaced);
 	bool StyleGetCheckMonospaced(int style);
+	void StyleSetInvisibleRepresentation(int style, const char *representation);
+	int StyleGetInvisibleRepresentation(int style, char *representation);
+	std::string StyleGetInvisibleRepresentation(int style);
 	void SetElementColour(Scintilla::Element element, ColourAlpha colourElement);
 	ColourAlpha ElementColour(Scintilla::Element element);
 	void ResetElementColour(Scintilla::Element element);
diff --git a/include/ScintillaMessages.h b/include/ScintillaMessages.h
index 663d6e12c..118655689 100644
--- a/include/ScintillaMessages.h
+++ b/include/ScintillaMessages.h
@@ -136,6 +136,8 @@ enum class Message {
 	StyleSetHotSpot = 2409,
 	StyleSetCheckMonospaced = 2254,
 	StyleGetCheckMonospaced = 2255,
+	StyleSetInvisibleRepresentation = 2256,
+	StyleGetInvisibleRepresentation = 2257,
 	SetElementColour = 2753,
 	GetElementColour = 2754,
 	ResetElementColour = 2755,
diff --git a/src/EditView.cxx b/src/EditView.cxx
index 86e59b4dc..8a7a50a7e 100644
--- a/src/EditView.cxx
+++ b/src/EditView.cxx
@@ -435,6 +435,21 @@ void LayoutSegments(IPositionCache *pCache,
 						std::string_view(&ll->chars[ts.start], ts.length), &ll->positions[ts.start + 1], multiThreaded);
 				}
 			}
+		} else if (vstyle.styles[ll->styles[ts.start]].invisibleRepresentation[0]) {
+			const int styleInvisible = ll->styles[ts.start];
+			const std::string_view text = vstyle.styles[styleInvisible].invisibleRepresentation;
+			XYPOSITION positionsRepr[Representation::maxLength + 1];
+			// invisibleRepresentation is UTF-8 which only matches cache if document is UTF-8
+			// or it only contains ASCII which is a subset of all currently supported encodings.
+			if (textUnicode || ViewIsASCII(text)) {
+				pCache->MeasureWidths(surface, vstyle, styleInvisible, text, positionsRepr, multiThreaded);
+			} else {
+				surface->MeasureWidthsUTF8(vstyle.styles[styleInvisible].font.get(), text, positionsRepr);
+			}
+			const XYPOSITION representationWidth = positionsRepr[text.length() - 1];
+			for (int ii = 0; ii < ts.length; ii++) {
+				ll->positions[ts.start + 1 + ii] = representationWidth;
+			}
 		}
 	}
 }
@@ -2230,6 +2245,15 @@ void EditView::DrawForeground(Surface *surface, const EditModel &model, const Vi
 						surface->DrawTextNoClip(rcSegment, textFont,
 							rcSegment.top + vsDraw.maxAscent, text, textFore, textBack);
 					}
+				} else if (vsDraw.styles[styleMain].invisibleRepresentation[0]) {
+					const std::string_view text = vsDraw.styles[styleMain].invisibleRepresentation;
+  					if (phasesDraw != PhasesDraw::One) {
+						surface->DrawTextTransparentUTF8(rcSegment, textFont,
+							rcSegment.top + vsDraw.maxAscent, text, textFore);
+					} else {
+						surface->DrawTextNoClipUTF8(rcSegment, textFont,
+							rcSegment.top + vsDraw.maxAscent, text, textFore, textBack);
+					}
 				}
 				if (vsDraw.viewWhitespace != WhiteSpace::Invisible ||
 					(inIndentation && vsDraw.viewIndentationGuides != IndentView::None)) {
diff --git a/src/Editor.cxx b/src/Editor.cxx
index 97c141bae..35148299e 100644
--- a/src/Editor.cxx
+++ b/src/Editor.cxx
@@ -5832,6 +5832,19 @@ void Editor::StyleSetMessage(Message iMessage, uptr_t wParam, sptr_t lParam) {
 	case Message::StyleSetVisible:
 		vs.styles[wParam].visible = lParam != 0;
 		break;
+	case Message::StyleSetInvisibleRepresentation: {
+		const char *utf8 = ConstCharPtrFromSPtr(lParam);
+		char *rep = vs.styles[wParam].invisibleRepresentation;
+		const int classified = UTF8Classify(utf8);
+		if (!(classified & UTF8MaskInvalid)) {
+			// valid UTF-8
+			int len = classified & UTF8MaskWidth;
+			while (len--)
+				*rep++ = *utf8++;
+		}
+		*rep = 0;
+		break;
+	}
 	case Message::StyleSetChangeable:
 		vs.styles[wParam].changeable = lParam != 0;
 		break;
@@ -5878,6 +5891,8 @@ sptr_t Editor::StyleGetMessage(Message iMessage, uptr_t wParam, sptr_t lParam) {
 		return vs.styles[wParam].visible ? 1 : 0;
 	case Message::StyleGetChangeable:
 		return vs.styles[wParam].changeable ? 1 : 0;
+	case Message::StyleGetInvisibleRepresentation:
+		return StringResult(lParam, vs.styles[wParam].invisibleRepresentation);
 	case Message::StyleGetHotSpot:
 		return vs.styles[wParam].hotspot ? 1 : 0;
 	case Message::StyleGetCheckMonospaced:
@@ -7328,6 +7343,7 @@ sptr_t Editor::WndProc(Message iMessage, uptr_t wParam, sptr_t lParam) {
 	case Message::StyleSetChangeable:
 	case Message::StyleSetHotSpot:
 	case Message::StyleSetCheckMonospaced:
+	case Message::StyleSetInvisibleRepresentation:
 		StyleSetMessage(iMessage, wParam, lParam);
 		break;
 
@@ -7347,6 +7363,7 @@ sptr_t Editor::WndProc(Message iMessage, uptr_t wParam, sptr_t lParam) {
 	case Message::StyleGetChangeable:
 	case Message::StyleGetHotSpot:
 	case Message::StyleGetCheckMonospaced:
+	case Message::StyleGetInvisibleRepresentation:
 		return StyleGetMessage(iMessage, wParam, lParam);
 
 	case Message::StyleResetDefault:
diff --git a/src/Style.cxx b/src/Style.cxx
index 76ffa4942..a45072292 100644
--- a/src/Style.cxx
+++ b/src/Style.cxx
@@ -72,7 +72,8 @@ Style::Style(const char *fontName_) noexcept :
 	caseForce(CaseForce::mixed),
 	visible(true),
 	changeable(true),
-	hotspot(false) {
+	hotspot(false),
+	invisibleRepresentation{} {
 }
 
 void Style::Copy(std::shared_ptr<Font> font_, const FontMeasurements &fm_) noexcept {
diff --git a/src/Style.h b/src/Style.h
index 6cef6bb60..da8159d6c 100644
--- a/src/Style.h
+++ b/src/Style.h
@@ -51,6 +51,7 @@ public:
 	bool visible;
 	bool changeable;
 	bool hotspot;
+	char invisibleRepresentation[5];
 
 	std::shared_ptr<Font> font;
 
diff --git a/test/simpleTests.py b/test/simpleTests.py
index 6c55c7cf4..92d6a92a7 100644
--- a/test/simpleTests.py
+++ b/test/simpleTests.py
@@ -1956,6 +1956,7 @@ class TestStyleAttributes(unittest.TestCase):
 		self.ed.EmptyUndoBuffer()
 		self.testColour = 0x171615
 		self.testFont = b"Georgia"
+		self.testRepresentation = "\N{BULLET}".encode("utf-8")
 
 	def tearDown(self):
 		self.ed.StyleResetDefault()
@@ -1971,6 +1972,13 @@ class TestStyleAttributes(unittest.TestCase):
 		self.ed.StyleSetSizeFractional(self.ed.STYLE_DEFAULT, 1234)
 		self.assertEquals(self.ed.StyleGetSizeFractional(self.ed.STYLE_DEFAULT), 1234)
 
+	def testInvisibleRepresentation(self):
+		self.assertEquals(self.ed.StyleGetInvisibleRepresentation(self.ed.STYLE_DEFAULT), b"")
+		self.ed.StyleSetInvisibleRepresentation(self.ed.STYLE_DEFAULT, self.testRepresentation)
+		self.assertEquals(self.ed.StyleGetInvisibleRepresentation(self.ed.STYLE_DEFAULT), self.testRepresentation)
+		self.ed.StyleSetInvisibleRepresentation(self.ed.STYLE_DEFAULT, b"\000")
+		self.assertEquals(self.ed.StyleGetInvisibleRepresentation(self.ed.STYLE_DEFAULT), b"")
+
 	def testBold(self):
 		self.ed.StyleSetBold(self.ed.STYLE_DEFAULT, 1)
 		self.assertEquals(self.ed.StyleGetBold(self.ed.STYLE_DEFAULT), 1)