Added PositionRelative to optimize navigation by character.

6 files changed, 62 insertions, 0 deletions

diff --git a/doc/ScintillaDoc.html b/doc/ScintillaDoc.html
index 57550bfe6..cca207dae 100644
--- a/doc/ScintillaDoc.html
+++ b/doc/ScintillaDoc.html
@@ -1161,6 +1161,7 @@ struct Sci_TextToFind {
     onlyWordCharacters)</a><br />
      <a class="message" href="#SCI_POSITIONBEFORE">SCI_POSITIONBEFORE(int position)</a><br />
      <a class="message" href="#SCI_POSITIONAFTER">SCI_POSITIONAFTER(int position)</a><br />
+     <a class="message" href="#SCI_POSITIONRELATIVE">SCI_POSITIONRELATIVE(int position, int relative)</a><br />
      <a class="message" href="#SCI_COUNTCHARACTERS">SCI_COUNTCHARACTERS(int startPos, int endPos)</a><br />
      <a class="message" href="#SCI_TEXTWIDTH">SCI_TEXTWIDTH(int styleNumber, const char *text)</a><br />
      <a class="message" href="#SCI_TEXTHEIGHT">SCI_TEXTHEIGHT(int line)</a><br />
@@ -1466,6 +1467,11 @@ struct Sci_TextToFind {
      If called with a position within a multi byte character will return the position
      of the start/end of that character.</p>
 
+    <p><b id="SCI_POSITIONRELATIVE">SCI_POSITIONRELATIVE(int position, int relative)</b><br />
+     Count a number of whole characters before or after the argument position and return that position.
+     The minimum position returned is 0 and the maximum is the last position in the document.
+     </p>
+
     <p><b id="SCI_COUNTCHARACTERS">SCI_COUNTCHARACTERS(int startPos, int endPos)</b><br />
      Returns the number of whole characters between two positions..</p>
 
diff --git a/doc/ScintillaHistory.html b/doc/ScintillaHistory.html
index e0ccc5966..97ff11f58 100644
--- a/doc/ScintillaHistory.html
+++ b/doc/ScintillaHistory.html
@@ -452,6 +452,9 @@
 	In Unicode mode C1 control characters are represented by their mnemonics.
 	</li>
 	<li>
+	Added SCI_POSITIONRELATIVE to optimize navigation by character.
+	</li>
+	<li>
 	Option to allow mouse selection to switch to rectangular by pressing Alt after start of gesture.
 	<a href="http://sourceforge.net/p/scintilla/feature-requests/1007/">Feature #1007.</a>
 	</li>
diff --git a/include/Scintilla.h b/include/Scintilla.h
index 5bfcfc266..405cc81f7 100644
--- a/include/Scintilla.h
+++ b/include/Scintilla.h
@@ -673,6 +673,7 @@ typedef sptr_t (*SciFnDirect)(sptr_t ptr, unsigned int iMessage, uptr_t wParam,
 #define SCI_PARAUPEXTEND 2416
 #define SCI_POSITIONBEFORE 2417
 #define SCI_POSITIONAFTER 2418
+#define SCI_POSITIONRELATIVE 2670
 #define SCI_COPYRANGE 2419
 #define SCI_COPYTEXT 2420
 #define SC_SEL_STREAM 0
diff --git a/include/Scintilla.iface b/include/Scintilla.iface
index f7880a035..7909f2084 100644
--- a/include/Scintilla.iface
+++ b/include/Scintilla.iface
@@ -1756,6 +1756,10 @@ fun position PositionBefore=2417(position pos,)
 # page into account. Maximum value returned is the last position in the document.
 fun position PositionAfter=2418(position pos,)
 
+# Given a valid document position, return a position that differs in a number
+# of characters. Returned value is always between 0 and last position in document.
+fun position PositionRelative=2670(position pos, int relative)
+
 # Copy a range of text to the clipboard. Positions are clipped into the document.
 fun void CopyRange=2419(position start, position end)
 
diff --git a/src/Editor.cxx b/src/Editor.cxx
index 7fa1326a7..afc2983ed 100644
--- a/src/Editor.cxx
+++ b/src/Editor.cxx
@@ -7605,6 +7605,9 @@ sptr_t Editor::WndProc(unsigned int iMessage, uptr_t wParam, sptr_t lParam) {
 	case SCI_POSITIONAFTER:
 		return pdoc->MovePositionOutsideChar(wParam + 1, 1, true);
 
+	case SCI_POSITIONRELATIVE:
+		return Platform::Clamp(pdoc->GetRelativePosition(wParam, lParam), 0, pdoc->Length());
+
 	case SCI_LINESCROLL:
 		ScrollTo(topLine + lParam);
 		HorizontalScrollTo(xOffset + static_cast<int>(wParam) * vs.spaceWidth);
diff --git a/test/simpleTests.py b/test/simpleTests.py
index 57607c375..30e74209d 100644
--- a/test/simpleTests.py
+++ b/test/simpleTests.py
@@ -1376,6 +1376,51 @@ class TestMultiSelection(unittest.TestCase):
 		self.assertEquals(self.ed.GetSelectionNCaret(0), 3)
 		self.assertEquals(self.ed.GetSelectionNCaretVirtualSpace(0), 0)
 
+class TestCharacterNavigation(unittest.TestCase):
+	def setUp(self):
+		self.xite = Xite.xiteFrame
+		self.ed = self.xite.ed
+		self.ed.ClearAll()
+		self.ed.EmptyUndoBuffer()
+		self.ed.SetCodePage(65001)
+
+	def tearDown(self):
+		self.ed.SetCodePage(0)
+
+	def testBeforeAfter(self):
+		t = "aåflﬔ-"
+		tv = t.encode("UTF-8")
+		self.ed.SetContents(tv)
+		pos = 0
+		for i in range(len(t)-1):
+			after = self.ed.PositionAfter(pos)
+			self.assert_(after > i)
+			back = self.ed.PositionBefore(after)
+			self.assertEquals(pos, back)
+			pos = after
+
+	def testRelative(self):
+		# \x61  \xc3\xa5  \xef\xac\x82   \xef\xac\x94   \x2d
+		t = "aåflﬔ-"
+		tv = t.encode("UTF-8")
+		self.ed.SetContents(tv)
+		self.assertEquals(self.ed.PositionRelative(1, 2), 6)
+		self.assertEquals(self.ed.PositionRelative(6, -2), 1)
+		pos = 0
+		previous = 0
+		for i in range(1, len(t)):
+			after = self.ed.PositionRelative(pos, i)
+			self.assert_(after > pos)
+			self.assert_(after > previous)
+			previous = after
+		pos = len(t)
+		previous = pos
+		for i in range(1, len(t)-1):
+			after = self.ed.PositionRelative(pos, -i)
+			self.assert_(after < pos)
+			self.assert_(after < previous)
+			previous = after
+
 class TestCaseMapping(unittest.TestCase):
 	def setUp(self):
 		self.xite = Xite.xiteFrame