Bug [#2141]. Implement end of line annotations.

13 files changed, 343 insertions, 4 deletions

diff --git a/doc/ScintillaDoc.html b/doc/ScintillaDoc.html
index 6ec941395..786b6f27f 100644
--- a/doc/ScintillaDoc.html
+++ b/doc/ScintillaDoc.html
@@ -457,6 +457,8 @@
         <tr>
           <td>&cir; <a class="toc" href="#BuildingScintilla">Building Scintilla</a></td>
 
+          <td>&cir; <a class="toc" href="#EndOfLineAnnotations">End of Line Annotations</a></td>
+
         </tr>
       </tbody>
     </table>
@@ -3725,6 +3727,99 @@ struct Sci_TextToFind {
     before <code>SCI_ANNOTATIONSETSTYLEOFFSET</code> and use the result as the argument to <code>SCI_ANNOTATIONSETSTYLEOFFSET</code>.
     </p>
 
+    <h2 id="EndOfLineAnnotations">End of Line Annotations</h2>
+
+    <p>End of Line Annotations are read-only lines of text at the end of each line of editable text.
+    End of Line Annotations can be used to display an assembler version of code for debugging or to show diagnostic messages inline or to
+    line up different versions of text in a merge tool.</p>
+
+    <p>End of Line Annotations used to display an assembler version of code for debugging</p>
+    <p><img src="eolannotation.png" alt="End of Line Annotations used to display an assembler version of code for debugging" /></p>
+
+    <code>
+     <a class="message" href="#SCI_EOLANNOTATIONSETTEXT">SCI_EOLANNOTATIONSETTEXT(line line, const char *text)</a><br />
+     <a class="message" href="#SCI_EOLANNOTATIONGETTEXT">SCI_EOLANNOTATIONGETTEXT(line line, char *text) &rarr; int</a><br />
+     <a class="message" href="#SCI_EOLANNOTATIONSETSTYLE">SCI_EOLANNOTATIONSETSTYLE(line line, int style)</a><br />
+     <a class="message" href="#SCI_EOLANNOTATIONGETSTYLE">SCI_EOLANNOTATIONGETSTYLE(line line) &rarr; int</a><br />
+     <a class="message" href="#SCI_EOLANNOTATIONCLEARALL">SCI_EOLANNOTATIONCLEARALL</a><br />
+     <a class="message" href="#SCI_EOLANNOTATIONSETVISIBLE">SCI_EOLANNOTATIONSETVISIBLE(int visible)</a><br />
+     <a class="message" href="#SCI_EOLANNOTATIONGETVISIBLE">SCI_EOLANNOTATIONGETVISIBLE &rarr; int</a><br />
+     <a class="message" href="#SCI_EOLANNOTATIONSETSTYLEOFFSET">SCI_EOLANNOTATIONSETSTYLEOFFSET(int style)</a><br />
+     <a class="message" href="#SCI_EOLANNOTATIONGETSTYLEOFFSET">SCI_EOLANNOTATIONGETSTYLEOFFSET &rarr; int</a><br />
+    </code>
+
+    <p>
+     <b id="SCI_EOLANNOTATIONSETTEXT">SCI_EOLANNOTATIONSETTEXT(line line, const char *text)</b><br />
+     <b id="SCI_EOLANNOTATIONGETTEXT">SCI_EOLANNOTATIONGETTEXT(line line, char *text) &rarr; int</b><br />
+     <b id="SCI_EOLANNOTATIONSETSTYLE">SCI_EOLANNOTATIONSETSTYLE(line line, int style)</b><br />
+     <b id="SCI_EOLANNOTATIONGETSTYLE">SCI_EOLANNOTATIONGETSTYLE(line line) &rarr; int</b><br />
+     <b id="SCI_EOLANNOTATIONCLEARALL">SCI_EOLANNOTATIONCLEARALL</b><br />
+     A different string may be set for each line with <code>SCI_EOLANNOTATIONSETTEXT</code>.
+     To clear end of line annotations call <code>SCI_EOLANNOTATIONSETTEXT</code> with a NULL pointer.
+     The whole of the text EOLANNOTATION on a line may be displayed in a particular style with
+     <code>SCI_EOLANNOTATIONSETSTYLE</code> or each character may be individually styled with
+     of the corresponding text byte similar to <code>SCI_SETSTYLINGEX</code>. The text must be set first as it
+     specifies how long the end of line annotation is so how many bytes of styling to read.
+     Setting an end of line annotation will cause a
+     <a class="message" href="#SC_MOD_CHANGEEOLANNOTATION"><code>SC_MOD_CHANGEEOLANNOTATION</code></a>
+     notification to be sent.
+    </p>
+    <p>
+    All the lines can be cleared of end of line annotations with <code>SCI_EOLANNOTATIONCLEARALL</code>
+    which is equivalent to clearing each line (setting to 0) and then deleting other memory used for this feature.
+    </p>
+    <p>
+    Only some style attributes are active in end of line annotations: font, size/sizeFractional, bold/weight, italics, fore, back, and characterSet.
+    </p>
+    <p>
+     <b id="SCI_EOLANNOTATIONSETVISIBLE">SCI_EOLANNOTATIONSETVISIBLE(int visible)</b><br />
+     <b id="SCI_EOLANNOTATIONGETVISIBLE">SCI_EOLANNOTATIONGETVISIBLE &rarr; int</b><br />
+     End of Line Annotations can be made visible in a view and there is a choice of display style when visible.
+     The two messages set and get the annotation display mode. The <code class="parameter">visible</code>
+     argument can be one of:</p>
+
+    <table class="standard" summary="End of Line Annotation visibility">
+      <tbody valign="top">
+        <tr>
+          <th align="left"><code>EOLANNOTATION_HIDDEN</code></th>
+
+          <td>0</td>
+
+          <td>End of Line Annotations are not displayed.</td>
+        </tr>
+
+        <tr>
+          <th align="left"><code>EOLANNOTATION_STANDARD</code></th>
+
+          <td>1</td>
+
+          <td>End of Line Annotations are drawn left justified with no adornment.</td>
+        </tr>
+
+        <tr>
+          <th align="left"><code>EOLANNOTATION_BOXED</code></th>
+
+          <td>2</td>
+
+          <td>End of Line Annotations are indented to match the text and are surrounded by a box.</td>
+        </tr>
+
+      </tbody>
+    </table>
+
+    <p>
+     <b id="SCI_EOLANNOTATIONSETSTYLEOFFSET">SCI_EOLANNOTATIONSETSTYLEOFFSET(int style)</b><br />
+     <b id="SCI_EOLANNOTATIONGETSTYLEOFFSET">SCI_EOLANNOTATIONGETSTYLEOFFSET &rarr; int</b><br />
+    End of Line Annotation styles may be completely separated from standard text styles by setting a style offset. For example,
+    <code>SCI_EOLANNOTATIONSETSTYLEOFFSET(512)</code> would allow the end of line  annotation styles to be numbered from
+    512 up to 767 so they do not overlap styles set by lexers (or margins if margins offset is 256).
+    Each style number set with <code>SCI_EOLANNOTATIONSETSTYLE</code>
+    or <code>SCI_EOLANNOTATIONSETSTYLES</code> has the offset added before looking up the style.
+    </p>
+    <p>
+    Always call <a class="seealso" href="#SCI_ALLOCATEEXTENDEDSTYLES">SCI_ALLOCATEEXTENDEDSTYLES</a>
+    before <code>SCI_EOLANNOTATIONSETSTYLEOFFSET</code> and use the result as the argument to <code>SCI_EOLANNOTATIONSETSTYLEOFFSET</code>.
+    </p>
     <h2 id="OtherSettings">Other settings</h2>
     <code>
      <a class="message" href="#SCI_SETBUFFEREDDRAW">SCI_SETBUFFEREDDRAW(bool buffered)</a><br />
diff --git a/doc/ScintillaHistory.html b/doc/ScintillaHistory.html
index c6d5b0539..10e88fd2a 100644
--- a/doc/ScintillaHistory.html
+++ b/doc/ScintillaHistory.html
@@ -555,6 +555,7 @@
 	<td>Shmuel Zeigerman</td>
 	<td>Chris Graham</td>
 	<td>Hugues Larrive</td>
+	<td>Prakash Sahni</td>
     </tr>
     </table>
     <p>
@@ -574,6 +575,10 @@
 	Released 3 June 2020.
 	</li>
 	<li>
+	End of line annotations implemented.
+	<a href="https://sourceforge.net/p/scintilla/bugs/2141/">Bug #2141</a>.
+	</li>
+	<li>
 	The latex lexer supports lstlisting environment that is similar to verbatim.
 	<a href="https://sourceforge.net/p/scintilla/feature-requests/1358/">Feature #1358</a>.
 	</li>
diff --git a/doc/eolannotation.png b/doc/eolannotation.png
new file mode 100644
index 000000000..5dacbf569
--- /dev/null
+++ b/doc/eolannotation.png
diff --git a/include/Scintilla.h b/include/Scintilla.h
index ad36c19b2..d3b6ac237 100644
--- a/include/Scintilla.h
+++ b/include/Scintilla.h
@@ -1005,6 +1005,18 @@ typedef sptr_t (*SciFnDirect)(sptr_t ptr, unsigned int iMessage, uptr_t wParam,
 #define SCI_SETREPRESENTATION 2665
 #define SCI_GETREPRESENTATION 2666
 #define SCI_CLEARREPRESENTATION 2667
+#define SCI_EOLANNOTATIONSETTEXT 2740
+#define SCI_EOLANNOTATIONGETTEXT 2741
+#define SCI_EOLANNOTATIONSETSTYLE 2742
+#define SCI_EOLANNOTATIONGETSTYLE 2743
+#define SCI_EOLANNOTATIONCLEARALL 2744
+#define EOLANNOTATION_HIDDEN 0
+#define EOLANNOTATION_STANDARD 1
+#define EOLANNOTATION_BOXED 2
+#define SCI_EOLANNOTATIONSETVISIBLE 2745
+#define SCI_EOLANNOTATIONGETVISIBLE 2746
+#define SCI_EOLANNOTATIONSETSTYLEOFFSET 2747
+#define SCI_EOLANNOTATIONGETSTYLEOFFSET 2748
 #define SCI_STARTRECORD 3001
 #define SCI_STOPRECORD 3002
 #define SCI_SETLEXER 4001
@@ -1065,7 +1077,8 @@ typedef sptr_t (*SciFnDirect)(sptr_t ptr, unsigned int iMessage, uptr_t wParam,
 #define SC_MOD_LEXERSTATE 0x80000
 #define SC_MOD_INSERTCHECK 0x100000
 #define SC_MOD_CHANGETABSTOPS 0x200000
-#define SC_MODEVENTMASKALL 0x3FFFFF
+#define SC_MOD_CHANGEEOLANNOTATION 0x400000
+#define SC_MODEVENTMASKALL 0x7FFFFF
 #define SC_UPDATE_CONTENT 0x1
 #define SC_UPDATE_SELECTION 0x2
 #define SC_UPDATE_V_SCROLL 0x4
diff --git a/include/Scintilla.iface b/include/Scintilla.iface
index 2d53ba391..b8d92da19 100644
--- a/include/Scintilla.iface
+++ b/include/Scintilla.iface
@@ -2837,6 +2837,38 @@ get int GetRepresentation=2666(string encodedCharacter, stringresult representat
 # Remove a character representation.
 fun void ClearRepresentation=2667(string encodedCharacter,)
 
+# Set the end of line annotation text for a line
+set void EOLAnnotationSetText=2740(line line, string text)
+
+# Get the end of line annotation text for a line
+get int EOLAnnotationGetText=2741(line line, stringresult text)
+
+# Set the style number for the end of line annotations for a line
+set void EOLAnnotationSetStyle=2742(line line, int style)
+
+# Get the style number for the end of line annotations for a line
+get int EOLAnnotationGetStyle=2743(line line,)
+
+# Clear the end of annotations from all lines
+fun void EOLAnnotationClearAll=2744(,)
+
+enu EOLAnnotationVisible=EOLANNOTATION_
+val EOLANNOTATION_HIDDEN=0
+val EOLANNOTATION_STANDARD=1
+val EOLANNOTATION_BOXED=2
+
+# Set the visibility for the end of line annotations for a view
+set void EOLAnnotationSetVisible=2745(EOLAnnotationVisible visible,)
+
+# Get the visibility for the end of line annotations for a view
+get EOLAnnotationVisible EOLAnnotationGetVisible=2746(,)
+
+# Get the start of the range of style numbers used for end of line annotations
+set void EOLAnnotationSetStyleOffset=2747(int style,)
+
+# Get the start of the range of style numbers used for end of line annotations
+get int EOLAnnotationGetStyleOffset=2748(,)
+
 # Start notifying the container of all key presses and commands.
 fun void StartRecord=3001(,)
 
@@ -2987,7 +3019,8 @@ val SC_MOD_CONTAINER=0x40000
 val SC_MOD_LEXERSTATE=0x80000
 val SC_MOD_INSERTCHECK=0x100000
 val SC_MOD_CHANGETABSTOPS=0x200000
-val SC_MODEVENTMASKALL=0x3FFFFF
+val SC_MOD_CHANGEEOLANNOTATION=0x400000
+val SC_MODEVENTMASKALL=0x7FFFFF
 
 ali SC_MOD_INSERTTEXT=INSERT_TEXT
 ali SC_MOD_DELETETEXT=DELETE_TEXT
@@ -3007,6 +3040,7 @@ ali SC_MOD_CHANGEANNOTATION=CHANGE_ANNOTATION
 ali SC_MOD_LEXERSTATE=LEXER_STATE
 ali SC_MOD_INSERTCHECK=INSERT_CHECK
 ali SC_MOD_CHANGETABSTOPS=CHANGE_TAB_STOPS
+ali SC_MOD_CHANGEEOLANNOTATION=CHANGE_E_O_L_ANNOTATION
 ali SC_MODEVENTMASKALL=EVENT_MASK_ALL
 
 enu Update=SC_UPDATE_
diff --git a/src/Document.cxx b/src/Document.cxx
index ff009ee3e..f17e4f837 100644
--- a/src/Document.cxx
+++ b/src/Document.cxx
@@ -137,6 +137,7 @@ Document::Document(int options) :
 	perLineData[ldState] = std::make_unique<LineState>();
 	perLineData[ldMargin] = std::make_unique<LineAnnotation>();
 	perLineData[ldAnnotation] = std::make_unique<LineAnnotation>();
+	perLineData[ldEOLAnnotation] = std::make_unique<LineAnnotation>();
 
 	decorations = DecorationListCreate(IsLarge());
 
@@ -212,6 +213,10 @@ LineAnnotation *Document::Annotations() const noexcept {
 	return dynamic_cast<LineAnnotation *>(perLineData[ldAnnotation].get());
 }
 
+LineAnnotation *Document::EOLAnnotations() const noexcept {
+	return dynamic_cast<LineAnnotation *>(perLineData[ldEOLAnnotation].get());
+}
+
 int Document::LineEndTypesSupported() const {
 	if ((SC_CP_UTF8 == dbcsCodePage) && pli)
 		return pli->LineEndTypesSupported();
@@ -2385,6 +2390,36 @@ void Document::AnnotationClearAll() {
 	Annotations()->ClearAll();
 }
 
+StyledText Document::EOLAnnotationStyledText(Sci::Line line) const noexcept {
+	const LineAnnotation *pla = EOLAnnotations();
+	return StyledText(pla->Length(line), pla->Text(line),
+		pla->MultipleStyles(line), pla->Style(line), pla->Styles(line));
+}
+
+void Document::EOLAnnotationSetText(Sci::Line line, const char *text) {
+	if (line >= 0 && line < LinesTotal()) {
+		EOLAnnotations()->SetText(line, text);
+		DocModification mh(SC_MOD_CHANGEEOLANNOTATION, LineStart(line),
+			0, 0, 0, line);
+		NotifyModified(mh);
+	}
+}
+
+void Document::EOLAnnotationSetStyle(Sci::Line line, int style) {
+	EOLAnnotations()->SetStyle(line, style);
+	const DocModification mh(SC_MOD_CHANGEEOLANNOTATION, LineStart(line),
+		0, 0, 0, line);
+	NotifyModified(mh);
+}
+
+void Document::EOLAnnotationClearAll() {
+	const Sci::Line maxEditorLine = LinesTotal();
+	for (Sci::Line l=0; l<maxEditorLine; l++)
+		EOLAnnotationSetText(l, nullptr);
+	// Free remaining data
+	EOLAnnotations()->ClearAll();
+}
+
 void Document::IncrementStyleClock() noexcept {
 	styleClock = (styleClock + 1) % 0x100000;
 }
diff --git a/src/Document.h b/src/Document.h
index a1017810e..6e8507f04 100644
--- a/src/Document.h
+++ b/src/Document.h
@@ -244,13 +244,14 @@ private:
 	std::vector<WatcherWithUserData> watchers;
 
 	// ldSize is not real data - it is for dimensions and loops
-	enum lineData { ldMarkers, ldLevels, ldState, ldMargin, ldAnnotation, ldSize };
+	enum lineData { ldMarkers, ldLevels, ldState, ldMargin, ldAnnotation, ldEOLAnnotation, ldSize };
 	std::unique_ptr<PerLine> perLineData[ldSize];
 	LineMarkers *Markers() const noexcept;
 	LineLevels *Levels() const noexcept;
 	LineState *States() const noexcept;
 	LineAnnotation *Margins() const noexcept;
 	LineAnnotation *Annotations() const noexcept;
+	LineAnnotation *EOLAnnotations() const noexcept;
 
 	bool matchesValid;
 	std::unique_ptr<RegexSearchBase> regex;
@@ -483,6 +484,11 @@ public:
 	int AnnotationLines(Sci::Line line) const noexcept;
 	void AnnotationClearAll();
 
+	StyledText EOLAnnotationStyledText(Sci::Line line) const noexcept;
+	void EOLAnnotationSetStyle(Sci::Line line, int style);
+	void EOLAnnotationSetText(Sci::Line line, const char *text);
+	void EOLAnnotationClearAll();
+
 	bool AddWatcher(DocWatcher *watcher, void *userData);
 	bool RemoveWatcher(DocWatcher *watcher, void *userData);
 
diff --git a/src/EditView.cxx b/src/EditView.cxx
index 9599e293f..290106a49 100644
--- a/src/EditView.cxx
+++ b/src/EditView.cxx
@@ -1050,7 +1050,8 @@ void EditView::DrawEOL(Surface *surface, const EditModel &model, const ViewStyle
 		rcSegment.left = rcLine.left;
 	rcSegment.right = rcLine.right;
 
-	const bool fillRemainder = !lastSubLine || !model.GetFoldDisplayText(line);
+	bool drawEOLAnnotationStyledText = (vsDraw.eolAnnotationVisible != EOLANNOTATION_HIDDEN) && model.pdoc->EOLAnnotationStyledText(line).text;
+	const bool fillRemainder = (!lastSubLine || (!model.GetFoldDisplayText(line) && !drawEOLAnnotationStyledText));
 	if (fillRemainder) {
 		// Fill the remainder of the line
 		FillLineRemainder(surface, model, vsDraw, ll, line, rcSegment, subLine);
@@ -1285,6 +1286,95 @@ void EditView::DrawFoldDisplayText(Surface *surface, const EditModel &model, con
 	}
 }
 
+void EditView::DrawEOLAnnotationText(Surface *surface, const EditModel &model, const ViewStyle &vsDraw, const LineLayout *ll, Sci::Line line, int xStart, PRectangle rcLine, int subLine, XYACCUMULATOR subLineStart, DrawPhase phase) {
+
+	const bool lastSubLine = subLine == (ll->lines - 1);
+	if (!lastSubLine)
+		return;
+
+	if (vsDraw.eolAnnotationVisible == EOLANNOTATION_HIDDEN) {
+		return;
+	}
+	const StyledText stEOLAnnotation = model.pdoc->EOLAnnotationStyledText(line);
+	if (!stEOLAnnotation.text || !ValidStyledText(vsDraw, vsDraw.eolAnnotationStyleOffset, stEOLAnnotation)) {
+		return;
+	}
+	const std::string_view eolAnnotationText(stEOLAnnotation.text, stEOLAnnotation.length);
+	const size_t style = stEOLAnnotation.style + vsDraw.eolAnnotationStyleOffset;
+
+	PRectangle rcSegment = rcLine;
+	FontAlias fontText = vsDraw.styles[style].font;
+	const int widthEOLAnnotationText = static_cast<int>(surface->WidthText(fontText, eolAnnotationText));
+
+	const XYPOSITION spaceWidth = vsDraw.styles[ll->EndLineStyle()].spaceWidth;
+	const XYPOSITION virtualSpace = model.sel.VirtualSpaceFor(
+		model.pdoc->LineEnd(line)) * spaceWidth;
+	rcSegment.left = xStart +
+		static_cast<XYPOSITION>(ll->positions[ll->numCharsInLine] - subLineStart)
+		+ virtualSpace + vsDraw.aveCharWidth;
+
+	const char *textFoldDisplay = model.GetFoldDisplayText(line);
+	if (textFoldDisplay) {
+		const std::string_view foldDisplayText(textFoldDisplay);
+		rcSegment.left += (static_cast<int>(surface->WidthText(fontText, foldDisplayText)) + vsDraw.aveCharWidth);
+	}
+	rcSegment.right = rcSegment.left + static_cast<XYPOSITION>(widthEOLAnnotationText);
+
+	const ColourOptional background = vsDraw.Background(model.pdoc->GetMark(line), model.caret.active, ll->containsCaret);
+	ColourDesired textFore = vsDraw.styles[style].fore;
+	const ColourDesired textBack = TextBackground(model, vsDraw, ll, background, false,
+											false, static_cast<int>(style), -1);
+
+	if (model.trackLineWidth) {
+		if (rcSegment.right + 1> lineWidthMaxSeen) {
+			// EOL Annotation text border drawn on rcSegment.right with width 1 is the last visible object of the line
+			lineWidthMaxSeen = static_cast<int>(rcSegment.right + 1);
+		}
+	}
+
+	if (phase & drawBack) {
+		surface->FillRectangle(rcSegment, textBack);
+
+		// Fill Remainder of the line
+		PRectangle rcRemainder = rcSegment;
+		rcRemainder.left = rcRemainder.right;
+		if (rcRemainder.left < rcLine.left)
+			rcRemainder.left = rcLine.left;
+		rcRemainder.right = rcLine.right;
+		FillLineRemainder(surface, model, vsDraw, ll, line, rcRemainder, subLine);
+	}
+
+	if (phase & drawText) {
+		if (phasesDraw != phasesOne) {
+			surface->DrawTextTransparent(rcSegment, fontText,
+			rcSegment.top + vsDraw.maxAscent, eolAnnotationText,
+			textFore);
+		} else {
+			surface->DrawTextNoClip(rcSegment, fontText,
+			rcSegment.top + vsDraw.maxAscent, eolAnnotationText,
+			textFore, textBack);
+		}
+	}
+
+	if (phase & drawIndicatorsFore) {
+		if (vsDraw.eolAnnotationVisible == EOLANNOTATION_BOXED ) {
+			surface->PenColour(textFore);
+			PRectangle rcBox = rcSegment;
+			rcBox.left = std::round(rcSegment.left);
+			rcBox.right = std::round(rcSegment.right);
+			const IntegerRectangle ircBox(rcBox);
+			surface->MoveTo(ircBox.left, ircBox.top);
+			surface->LineTo(ircBox.left, ircBox.bottom);
+			surface->MoveTo(ircBox.right, ircBox.top);
+			surface->LineTo(ircBox.right, ircBox.bottom);
+			surface->MoveTo(ircBox.left, ircBox.top);
+			surface->LineTo(ircBox.right, ircBox.top);
+			surface->MoveTo(ircBox.left, ircBox.bottom - 1);
+			surface->LineTo(ircBox.right, ircBox.bottom - 1);
+		}
+	}
+}
+
 static constexpr bool AnnotationBoxedOrIndented(int annotationVisible) noexcept {
 	return annotationVisible == ANNOTATION_BOXED || annotationVisible == ANNOTATION_INDENTED;
 }
@@ -2039,6 +2129,7 @@ void EditView::DrawLine(Surface *surface, const EditModel &model, const ViewStyl
 			DrawBackground(surface, model, vsDraw, ll, rcLine, lineRange, posLineStart, xStart,
 				subLine, background);
 			DrawFoldDisplayText(surface, model, vsDraw, ll, line, xStart, rcLine, subLine, subLineStart, drawBack);
+			DrawEOLAnnotationText(surface, model, vsDraw, ll, line, xStart, rcLine, subLine, subLineStart, drawBack);
 			phase = static_cast<DrawPhase>(phase & ~drawBack);	// Remove drawBack to not draw again in DrawFoldDisplayText
 			DrawEOL(surface, model, vsDraw, ll, rcLine, line, lineRange.end,
 				xStart, subLine, subLineStart, background);
@@ -2069,6 +2160,7 @@ void EditView::DrawLine(Surface *surface, const EditModel &model, const ViewStyl
 	}
 
 	DrawFoldDisplayText(surface, model, vsDraw, ll, line, xStart, rcLine, subLine, subLineStart, phase);
+	DrawEOLAnnotationText(surface, model, vsDraw, ll, line, xStart, rcLine, subLine, subLineStart, phase);
 
 	if (phasesDraw == phasesOne) {
 		DrawEOL(surface, model, vsDraw, ll, rcLine, line, lineRange.end,
diff --git a/src/EditView.h b/src/EditView.h
index 6eb63a686..8f544f280 100644
--- a/src/EditView.h
+++ b/src/EditView.h
@@ -133,6 +133,8 @@ public:
 		ColourOptional background);
 	void DrawFoldDisplayText(Surface *surface, const EditModel &model, const ViewStyle &vsDraw, const LineLayout *ll,
 		Sci::Line line, int xStart, PRectangle rcLine, int subLine, XYACCUMULATOR subLineStart, DrawPhase phase);
+	void DrawEOLAnnotationText(Surface *surface, const EditModel &model, const ViewStyle &vsDraw, const LineLayout *ll,
+		Sci::Line line, int xStart, PRectangle rcLine, int subLine, XYACCUMULATOR subLineStart, DrawPhase phase);
 	void DrawAnnotation(Surface *surface, const EditModel &model, const ViewStyle &vsDraw, const LineLayout *ll,
 		Sci::Line line, int xStart, PRectangle rcLine, int subLine, DrawPhase phase);
 	void DrawCarets(Surface *surface, const EditModel &model, const ViewStyle &vsDraw, const LineLayout *ll, Sci::Line lineDoc,
diff --git a/src/Editor.cxx b/src/Editor.cxx
index 234a2aaa6..12688da66 100644
--- a/src/Editor.cxx
+++ b/src/Editor.cxx
@@ -2126,6 +2126,7 @@ void Editor::ClearAll() {
 		if (!pdoc->IsReadOnly()) {
 			pcs->Clear();
 			pdoc->AnnotationClearAll();
+			pdoc->EOLAnnotationClearAll();
 			pdoc->MarginClearAll();
 		}
 	}
@@ -2661,6 +2662,11 @@ void Editor::NotifyModified(Document *, DocModification mh, void *) {
 				Redraw();
 			}
 		}
+		if (mh.modificationType & SC_MOD_CHANGEEOLANNOTATION) {
+			if (vs.eolAnnotationVisible) {
+				Redraw();
+			}
+		}
 		CheckModificationForWrap(mh);
 		if (mh.linesAdded != 0) {
 			// Avoid scrolling of display if change before current display
@@ -5303,6 +5309,13 @@ void Editor::SetAnnotationVisible(int visible) {
 	}
 }
 
+void Editor::SetEOLAnnotationVisible(int visible) {
+	if (vs.eolAnnotationVisible != visible) {
+		vs.eolAnnotationVisible = visible;
+		Redraw();
+	}
+}
+
 /**
  * Recursively expand a fold, making lines visible except where they have an unexpanded parent.
  */
@@ -8069,6 +8082,43 @@ sptr_t Editor::WndProc(unsigned int iMessage, uptr_t wParam, sptr_t lParam) {
 	case SCI_ANNOTATIONGETSTYLEOFFSET:
 		return vs.annotationStyleOffset;
 
+	case SCI_EOLANNOTATIONSETTEXT:
+		pdoc->EOLAnnotationSetText(static_cast<Sci::Line>(wParam), CharPtrFromSPtr(lParam));
+		break;
+
+	case SCI_EOLANNOTATIONGETTEXT: {
+			const StyledText st = pdoc->EOLAnnotationStyledText(static_cast<Sci::Line>(wParam));
+			return BytesResult(lParam, reinterpret_cast<const unsigned char *>(st.text), st.length);
+		}
+
+	case SCI_EOLANNOTATIONGETSTYLE: {
+			const StyledText st = pdoc->EOLAnnotationStyledText(static_cast<Sci::Line>(wParam));
+			return st.style;
+		}
+
+	case SCI_EOLANNOTATIONSETSTYLE:
+		pdoc->EOLAnnotationSetStyle(static_cast<Sci::Line>(wParam), static_cast<int>(lParam));
+		break;
+
+	case SCI_EOLANNOTATIONCLEARALL:
+		pdoc->EOLAnnotationClearAll();
+		break;
+
+	case SCI_EOLANNOTATIONSETVISIBLE:
+		SetEOLAnnotationVisible(static_cast<int>(wParam));
+		break;
+
+	case SCI_EOLANNOTATIONGETVISIBLE:
+		return vs.eolAnnotationVisible;
+
+	case SCI_EOLANNOTATIONSETSTYLEOFFSET:
+		vs.eolAnnotationStyleOffset = static_cast<int>(wParam);
+		InvalidateStyleRedraw();
+		break;
+
+	case SCI_EOLANNOTATIONGETSTYLEOFFSET:
+		return vs.eolAnnotationStyleOffset;
+
 	case SCI_RELEASEALLEXTENDEDSTYLES:
 		vs.ReleaseAllExtendedStyles();
 		break;
diff --git a/src/Editor.h b/src/Editor.h
index dda14c311..74137cd48 100644
--- a/src/Editor.h
+++ b/src/Editor.h
@@ -546,6 +546,7 @@ protected:	// ScintillaBase subclass needs access to much of Editor
 	virtual void SetDocPointer(Document *document);
 
 	void SetAnnotationVisible(int visible);
+	void SetEOLAnnotationVisible(int visible);
 
 	Sci::Line ExpandLine(Sci::Line line);
 	void SetFoldExpanded(Sci::Line lineDoc, bool expanded);
diff --git a/src/ViewStyle.cxx b/src/ViewStyle.cxx
index b23d7d695..fab1a2406 100644
--- a/src/ViewStyle.cxx
+++ b/src/ViewStyle.cxx
@@ -129,6 +129,8 @@ ViewStyle::ViewStyle(const ViewStyle &source) : markers(MARKER_MAX + 1), indicat
 	marginStyleOffset = source.marginStyleOffset;
 	annotationVisible = source.annotationVisible;
 	annotationStyleOffset = source.annotationStyleOffset;
+	eolAnnotationVisible = source.eolAnnotationVisible;
+	eolAnnotationStyleOffset = source.eolAnnotationStyleOffset;
 	braceHighlightIndicatorSet = source.braceHighlightIndicatorSet;
 	braceHighlightIndicator = source.braceHighlightIndicator;
 	braceBadLightIndicatorSet = source.braceBadLightIndicatorSet;
@@ -262,6 +264,8 @@ void ViewStyle::Init(size_t stylesSize_) {
 	marginStyleOffset = 0;
 	annotationVisible = ANNOTATION_HIDDEN;
 	annotationStyleOffset = 0;
+	eolAnnotationVisible = EOLANNOTATION_HIDDEN;
+	eolAnnotationStyleOffset = 0;
 	braceHighlightIndicatorSet = false;
 	braceHighlightIndicator = 0;
 	braceBadLightIndicatorSet = false;
diff --git a/src/ViewStyle.h b/src/ViewStyle.h
index 33ea1d6c2..e5bf375f4 100644
--- a/src/ViewStyle.h
+++ b/src/ViewStyle.h
@@ -145,6 +145,8 @@ public:
 	int marginStyleOffset;
 	int annotationVisible;
 	int annotationStyleOffset;
+	int eolAnnotationVisible;
+	int eolAnnotationStyleOffset;
 	bool braceHighlightIndicatorSet;
 	int braceHighlightIndicator;
 	bool braceBadLightIndicatorSet;