From: Enrico Forestieri <forenr@lyx.org>
Date: Fri, 26 Feb 2021 19:30:41 +0000 (+0100)
Subject: Fix cursor navigation in \overbrace and \underbrace
X-Git-Url: https://git.lyx.org/gitweb/?a=commitdiff_plain;h=c2facb8c565610d6a702c39b2f95572551f624be;p=features.git

Fix cursor navigation in \overbrace and \underbrace

Due to the way these decorations are implemented, entering
them with the cursor (either form right or left) required
pressing two times cursor left or right.

Fixes #2264
---

diff --git a/src/Cursor.cpp b/src/Cursor.cpp
index fae9d85c3f..1d492d2c4b 100644
--- a/src/Cursor.cpp
+++ b/src/Cursor.cpp
@@ -2037,20 +2037,39 @@ bool Cursor::mathForward(bool word)
 					posForward();
 				while (pos() < lastpos() && mc == nextMath().mathClass());
 		} else if (openable(nextAtom())) {
+			InsetMathScript const * n = nextMath().asScriptInset();
+			bool to_brace_deco = n
+				&& n->nuc().back()->lyxCode() == MATH_DECORATION_CODE
+				&& n->nuc().back()->mathClass() == MC_OP;
 			// single step: try to enter the next inset
 			pushBackward(nextMath());
 			inset().idxFirst(*this);
+			// Make sure the cursor moves directly to an
+			// \overbrace or \underbrace inset (bug 2264)
+			if (to_brace_deco) {
+				pushBackward(nextMath());
+				inset().idxFirst(*this);
+			}
 		} else
 			posForward();
 		return true;
 	}
 	if (inset().idxForward(*this))
 		return true;
+	InsetMath const * m = inset().asInsetMath();
+	bool from_brace_deco = m
+		&& m->lyxCode() == MATH_DECORATION_CODE
+		&& m->mathClass() == MC_OP;
 	// try to pop forwards --- but don't pop out of math! leave that to
 	// the FINISH lfuns
 	int s = depth() - 2;
-	if (s >= 0 && operator[](s).inset().asInsetMath())
-		return popForward();
+	if (s >= 0 && operator[](s).inset().asInsetMath() && popForward()) {
+		// Make sure the cursor moves directly to an
+		// \overbrace or \underbrace inset (bug 2264)
+		bool to_script = inset().asInsetMath()
+			&& inset().asInsetMath()->asScriptInset();
+		return from_brace_deco && to_script ? mathForward(word) : true;
+	}
 	return false;
 }
 
@@ -2072,21 +2091,41 @@ bool Cursor::mathBackward(bool word)
 				while (pos() > 0 && mc == prevMath().mathClass());
 			}
 		} else if (openable(prevAtom())) {
+			InsetMathScript const * p = prevMath().asScriptInset();
+			bool to_brace_deco = p
+				&& p->nuc().back()->lyxCode() == MATH_DECORATION_CODE
+				&& p->nuc().back()->mathClass() == MC_OP;
 			// single step: try to enter the preceding inset
 			posBackward();
 			push(nextMath());
 			inset().idxLast(*this);
+			// Make sure the cursor moves directly to an
+			// \overbrace or \underbrace inset (bug 2264)
+			if (to_brace_deco) {
+				posBackward();
+				push(nextMath());
+				inset().idxLast(*this);
+			}
 		} else
 			posBackward();
 		return true;
 	}
 	if (inset().idxBackward(*this))
 		return true;
+	InsetMath const * m = inset().asInsetMath();
+	bool from_brace_deco = m
+		&& m->lyxCode() == MATH_DECORATION_CODE
+		&& m->mathClass() == MC_OP;
 	// try to pop backwards --- but don't pop out of math! leave that to
 	// the FINISH lfuns
 	int s = depth() - 2;
-	if (s >= 0 && operator[](s).inset().asInsetMath())
-		return popBackward();
+	if (s >= 0 && operator[](s).inset().asInsetMath() && popBackward()) {
+		// Make sure the cursor moves directly to an
+		// \overbrace or \underbrace inset (bug 2264)
+		bool to_script = inset().asInsetMath()
+			&& inset().asInsetMath()->asScriptInset();
+		return from_brace_deco && to_script ? mathBackward(word) : true;
+	}
 	return false;
 }