Change the way that selections and carets are drawn to use the element APIs.

4 files changed, 195 insertions, 166 deletions

diff --git a/src/EditView.cxx b/src/EditView.cxx
index 2d32c8997..5549e73db 100644
--- a/src/EditView.cxx
+++ b/src/EditView.cxx
@@ -826,42 +826,46 @@ namespace {
 
 constexpr ColourAlpha bugColour = ColourAlpha(0xff, 0, 0xff, 0xf0);
 
-ColourAlpha SelectionBackground(const EditModel &model, const ViewStyle &vsDraw, InSelection inSelection) noexcept {
+// Selection background colours are always defined, the value_or is to show if bug
+
+ColourAlpha SelectionBackground(const EditModel &model, const ViewStyle &vsDraw, InSelection inSelection) {
 	if (inSelection == InSelection::inNone)
 		return bugColour;	// Not selected is a bug
 
-	if (!vsDraw.selection.colours.back)
-		return bugColour;	// Not set -> bug
-
+	int element = SC_ELEMENT_SELECTION_BACK;
+	if (inSelection == InSelection::inAdditional)
+		element = SC_ELEMENT_SELECTION_ADDITIONAL_BACK;
 	if (!model.primarySelection)
-		return vsDraw.selection.background2;	// Secondary selection
-
-	if (inSelection == InSelection::inMain)
-		return *vsDraw.selection.colours.back;	// Main selection
-
-	return vsDraw.selection.additionalBackground;	// Additional selection
+		element = SC_ELEMENT_SELECTION_SECONDARY_BACK;
+	if (!model.hasFocus && vsDraw.ElementColour(SC_ELEMENT_SELECTION_NO_FOCUS_BACK))
+		element = SC_ELEMENT_SELECTION_NO_FOCUS_BACK;
+	return vsDraw.ElementColour(element).value_or(bugColour);
 }
 
-std::optional<ColourAlpha> SelectionForeground(const ViewStyle &vsDraw, InSelection inSelection) noexcept {
+std::optional<ColourAlpha> SelectionForeground(const EditModel &model, const ViewStyle &vsDraw, InSelection inSelection) {
 	if (inSelection == InSelection::inNone)
 		return {};
-	if (inSelection == InSelection::inMain)
-		return vsDraw.selection.colours.fore;
-	if (!vsDraw.selection.colours.fore)	// Main not set means don't use additional either
-		return {};
-	return vsDraw.selection.additionalForeground;
+	int element = SC_ELEMENT_SELECTION_TEXT;
+	if (inSelection == InSelection::inAdditional)
+		element = SC_ELEMENT_SELECTION_ADDITIONAL_TEXT;
+	if (!model.primarySelection)	// Secondary selection
+		element = SC_ELEMENT_SELECTION_SECONDARY_TEXT;
+	if (!model.hasFocus) {
+		if (vsDraw.ElementColour(SC_ELEMENT_SELECTION_NO_FOCUS_TEXT)) {
+			element = SC_ELEMENT_SELECTION_NO_FOCUS_TEXT;
+		} else {
+			return {};
+		}
+	}
+	return vsDraw.ElementColour(element);
 }
 
 }
 
 static ColourAlpha TextBackground(const EditModel &model, const ViewStyle &vsDraw, const LineLayout *ll,
-	std::optional<ColourAlpha> background, InSelection inSelection, bool inHotspot, int styleMain, Sci::Position i) noexcept {
-	if (inSelection && vsDraw.selection.colours.back) {
-		if ((inSelection == InSelection::inMain) && (vsDraw.selection.alpha == SC_ALPHA_NOALPHA)) {
-			return SelectionBackground(model, vsDraw, inSelection);
-		} else if ((inSelection == InSelection::inAdditional) && (vsDraw.selection.additionalAlpha == SC_ALPHA_NOALPHA)) {
-			return SelectionBackground(model, vsDraw, inSelection);
-		}
+	std::optional<ColourAlpha> background, InSelection inSelection, bool inHotspot, int styleMain, Sci::Position i) {
+	if (inSelection && (vsDraw.selection.layer == Layer::base)) {
+		return SelectionBackground(model, vsDraw, inSelection).Opaque();
 	}
 	if ((vsDraw.edgeState == EDGE_BACKGROUND) &&
 		(i >= ll->edgeColumn) &&
@@ -968,34 +972,30 @@ void EditView::DrawEOL(Surface *surface, const EditModel &model, const ViewStyle
 		rcSegment.right = xEol + xStart + virtualSpace;
 		const ColourAlpha backgroundFill = background.value_or(vsDraw.styles[ll->styles[ll->numCharsInLine]].back);
 		surface->FillRectangleAligned(rcSegment, backgroundFill);
-		if (!hideSelection && ((vsDraw.selection.alpha == SC_ALPHA_NOALPHA) || (vsDraw.selection.additionalAlpha == SC_ALPHA_NOALPHA))) {
+		if (!hideSelection && (vsDraw.selection.layer == Layer::base)) {
 			const SelectionSegment virtualSpaceRange(SelectionPosition(model.pdoc->LineEnd(line)),
 				SelectionPosition(model.pdoc->LineEnd(line),
 					model.sel.VirtualSpaceFor(model.pdoc->LineEnd(line))));
 			for (size_t r = 0; r<model.sel.Count(); r++) {
-				const int alpha = (r == model.sel.Main()) ? vsDraw.selection.alpha : vsDraw.selection.additionalAlpha;
-				if (alpha == SC_ALPHA_NOALPHA) {
-					const SelectionSegment portion = model.sel.Range(r).Intersect(virtualSpaceRange);
-					if (!portion.Empty()) {
-						const XYPOSITION spaceWidth = vsDraw.styles[ll->EndLineStyle()].spaceWidth;
-						rcSegment.left = xStart + ll->positions[portion.start.Position() - posLineStart] -
-							static_cast<XYPOSITION>(subLineStart)+portion.start.VirtualSpace() * spaceWidth;
-						rcSegment.right = xStart + ll->positions[portion.end.Position() - posLineStart] -
-							static_cast<XYPOSITION>(subLineStart)+portion.end.VirtualSpace() * spaceWidth;
-						rcSegment.left = (rcSegment.left > rcLine.left) ? rcSegment.left : rcLine.left;
-						rcSegment.right = (rcSegment.right < rcLine.right) ? rcSegment.right : rcLine.right;
-						surface->FillRectangleAligned(rcSegment, Fill(SelectionBackground(model, vsDraw, model.sel.RangeType(r))));
-					}
+				const SelectionSegment portion = model.sel.Range(r).Intersect(virtualSpaceRange);
+				if (!portion.Empty()) {
+					const XYPOSITION spaceWidth = vsDraw.styles[ll->EndLineStyle()].spaceWidth;
+					rcSegment.left = xStart + ll->positions[portion.start.Position() - posLineStart] -
+						static_cast<XYPOSITION>(subLineStart)+portion.start.VirtualSpace() * spaceWidth;
+					rcSegment.right = xStart + ll->positions[portion.end.Position() - posLineStart] -
+						static_cast<XYPOSITION>(subLineStart)+portion.end.VirtualSpace() * spaceWidth;
+					rcSegment.left = (rcSegment.left > rcLine.left) ? rcSegment.left : rcLine.left;
+					rcSegment.right = (rcSegment.right < rcLine.right) ? rcSegment.right : rcLine.right;
+					surface->FillRectangleAligned(rcSegment, Fill(
+						SelectionBackground(model, vsDraw, model.sel.RangeType(r)).Opaque()));
 				}
 			}
 		}
 	}
 
 	InSelection eolInSelection = InSelection::inNone;
-	int alpha = SC_ALPHA_NOALPHA;
 	if (!hideSelection && lastSubLine) {
 		eolInSelection = model.LineEndInSelection(line);
-		alpha = (eolInSelection == InSelection::inMain) ? vsDraw.selection.alpha : vsDraw.selection.additionalAlpha;
 	}
 
 	const ColourAlpha selectionBack = SelectionBackground(model, vsDraw, eolInSelection);
@@ -1024,11 +1024,11 @@ void EditView::DrawEOL(Surface *surface, const EditModel &model, const ViewStyle
 					ctrlChar = hexits;
 				}
 			}
-			const std::optional<ColourAlpha> selectionFore = SelectionForeground(vsDraw, eolInSelection);
+			const std::optional<ColourAlpha> selectionFore = SelectionForeground(model, vsDraw, eolInSelection);
 			const ColourAlpha textFore = selectionFore.value_or(vsDraw.styles[styleMain].fore);
-			if (eolInSelection && vsDraw.selection.colours.back && (line < model.pdoc->LinesTotal() - 1)) {
-				if (alpha == SC_ALPHA_NOALPHA) {
-					surface->FillRectangleAligned(rcSegment, Fill(selectionBack));
+			if (eolInSelection && (line < model.pdoc->LinesTotal() - 1)) {
+				if (vsDraw.selection.layer == Layer::base) {
+					surface->FillRectangleAligned(rcSegment, Fill(selectionBack.Opaque()));
 				} else {
 					surface->FillRectangleAligned(rcSegment, Fill(textBack));
 				}
@@ -1036,8 +1036,8 @@ void EditView::DrawEOL(Surface *surface, const EditModel &model, const ViewStyle
 				surface->FillRectangleAligned(rcSegment, Fill(textBack));
 			}
 			DrawTextBlob(surface, vsDraw, rcSegment, ctrlChar, textBack, textFore, phasesDraw == PhasesDraw::one);
-			if (eolInSelection && vsDraw.selection.colours.back && (line < model.pdoc->LinesTotal() - 1) && (alpha != SC_ALPHA_NOALPHA)) {
-				surface->FillRectangleAligned(rcSegment, ColourAlpha(selectionBack, alpha));
+			if (eolInSelection && (line < model.pdoc->LinesTotal() - 1) && (vsDraw.selection.layer == Layer::over)) {
+				surface->FillRectangleAligned(rcSegment, selectionBack);
 			}
 		}
 	}
@@ -1046,8 +1046,8 @@ void EditView::DrawEOL(Surface *surface, const EditModel &model, const ViewStyle
 	rcSegment.left = xEol + xStart + virtualSpace + blobsWidth;
 	rcSegment.right = rcSegment.left + vsDraw.aveCharWidth;
 
-	if (eolInSelection && vsDraw.selection.colours.back && (line < model.pdoc->LinesTotal() - 1) && (alpha == SC_ALPHA_NOALPHA)) {
-		surface->FillRectangleAligned(rcSegment, Fill(selectionBack));
+	if (eolInSelection && (line < model.pdoc->LinesTotal() - 1) && (vsDraw.selection.layer == Layer::base)) {
+		surface->FillRectangleAligned(rcSegment, Fill(selectionBack.Opaque()));
 	} else {
 		if (background) {
 			surface->FillRectangleAligned(rcSegment, Fill(*background));
@@ -1058,8 +1058,8 @@ void EditView::DrawEOL(Surface *surface, const EditModel &model, const ViewStyle
 		} else {
 			surface->FillRectangleAligned(rcSegment, Fill(vsDraw.styles[STYLE_DEFAULT].back));
 		}
-		if (eolInSelection && vsDraw.selection.colours.back && (line < model.pdoc->LinesTotal() - 1) && (alpha != SC_ALPHA_NOALPHA)) {
-			surface->FillRectangleAligned(rcSegment, ColourAlpha(selectionBack, alpha));
+		if (eolInSelection && (line < model.pdoc->LinesTotal() - 1) && (vsDraw.selection.layer == Layer::over)) {
+			surface->FillRectangleAligned(rcSegment, selectionBack);
 		}
 	}
 
@@ -1227,10 +1227,8 @@ void EditView::DrawFoldDisplayText(Surface *surface, const EditModel &model, con
 	const int widthFoldDisplayText = static_cast<int>(surface->WidthText(fontText, foldDisplayText));
 
 	InSelection eolInSelection = InSelection::inNone;
-	int alpha = SC_ALPHA_NOALPHA;
 	if (!hideSelection) {
 		eolInSelection = model.LineEndInSelection(line);
-		alpha = (eolInSelection == InSelection::inMain) ? vsDraw.selection.alpha : vsDraw.selection.additionalAlpha;
 	}
 
 	const XYPOSITION spaceWidth = vsDraw.styles[ll->EndLineStyle()].spaceWidth;
@@ -1240,7 +1238,7 @@ void EditView::DrawFoldDisplayText(Surface *surface, const EditModel &model, con
 	rcSegment.right = rcSegment.left + static_cast<XYPOSITION>(widthFoldDisplayText);
 
 	const std::optional<ColourAlpha> background = vsDraw.Background(model.pdoc->GetMark(line), model.caret.active, ll->containsCaret);
-	const std::optional<ColourAlpha> selectionFore = SelectionForeground(vsDraw, eolInSelection);
+	const std::optional<ColourAlpha> selectionFore = SelectionForeground(model, vsDraw, eolInSelection);
 	const ColourAlpha textFore = selectionFore.value_or(vsDraw.styles[STYLE_FOLDDISPLAYTEXT].fore);
 	const ColourAlpha textBack = TextBackground(model, vsDraw, ll, background, eolInSelection,
 											false, STYLE_FOLDDISPLAYTEXT, -1);
@@ -1286,8 +1284,8 @@ void EditView::DrawFoldDisplayText(Surface *surface, const EditModel &model, con
 	}
 
 	if (FlagSet(phase, DrawPhase::selectionTranslucent)) {
-		if (eolInSelection && vsDraw.selection.colours.back && (line < model.pdoc->LinesTotal() - 1) && alpha != SC_ALPHA_NOALPHA) {
-			surface->FillRectangleAligned(rcSegment, ColourAlpha(SelectionBackground(model, vsDraw, eolInSelection), alpha));
+		if (eolInSelection && (line < model.pdoc->LinesTotal() - 1) && (vsDraw.selection.layer == Layer::over)) {
+			surface->FillRectangleAligned(rcSegment, SelectionBackground(model, vsDraw, eolInSelection));
 		}
 	}
 }
@@ -1644,8 +1642,11 @@ void EditView::DrawCarets(Surface *surface, const EditModel &model, const ViewSt
 					rcCaret.left = std::round(xposCaret - caretWidthOffset);
 					rcCaret.right = rcCaret.left + vsDraw.caret.width;
 				}
-				const ColourAlpha caretColour = mainCaret ? vsDraw.caret.colour : vsDraw.caret.additionalColour;
-				assert(caretColour.IsOpaque());
+				int elementCaret = mainCaret ? SC_ELEMENT_CARET : SC_ELEMENT_CARET_ADDITIONAL;
+				if (!model.primarySelection)
+					elementCaret = SC_ELEMENT_CARET_SECONDARY;
+				const ColourAlpha caretColour = *vsDraw.ElementColour(elementCaret);
+				//assert(caretColour.IsOpaque());
 				if (drawBlockCaret) {
 					DrawBlockCaret(surface, model, vsDraw, ll, subLine, xStart, offset, posCaret.Position(), rcCaret, caretColour);
 				} else {
@@ -1808,7 +1809,7 @@ static void DrawMarkUnderline(Surface *surface, const EditModel &model, const Vi
 
 static void DrawTranslucentSelection(Surface *surface, const EditModel &model, const ViewStyle &vsDraw, const LineLayout *ll,
 	Sci::Line line, PRectangle rcLine, int subLine, Range lineRange, int xStart, int tabWidthMinimumPixels) {
-	if ((vsDraw.selection.alpha != SC_ALPHA_NOALPHA) || (vsDraw.selection.additionalAlpha != SC_ALPHA_NOALPHA)) {
+	if (vsDraw.selection.layer == Layer::over) {
 		const Sci::Position posLineStart = model.pdoc->LineStart(line);
 		const XYACCUMULATOR subLineStart = ll->positions[lineRange.start];
 		// For each selection draw
@@ -1820,51 +1821,48 @@ static void DrawTranslucentSelection(Surface *surface, const EditModel &model, c
 		const SelectionPosition posEnd(posLineStart + lineRange.end, virtualSpaces);
 		const SelectionSegment virtualSpaceRange(posStart, posEnd);
 		for (size_t r = 0; r < model.sel.Count(); r++) {
-			const int alpha = (r == model.sel.Main()) ? vsDraw.selection.alpha : vsDraw.selection.additionalAlpha;
-			if (alpha != SC_ALPHA_NOALPHA) {
-				const SelectionSegment portion = model.sel.Range(r).Intersect(virtualSpaceRange);
-				if (!portion.Empty()) {
-					const ColourAlpha selectionBack = ColourAlpha(
-						SelectionBackground(model, vsDraw, model.sel.RangeType(r)), alpha);
-					const XYPOSITION spaceWidth = vsDraw.styles[ll->EndLineStyle()].spaceWidth;
-					if (model.BidirectionalEnabled()) {
-						const int selectionStart = static_cast<int>(portion.start.Position() - posLineStart - lineRange.start);
-						const int selectionEnd = static_cast<int>(portion.end.Position() - posLineStart - lineRange.start);
-
-						const ScreenLine screenLine(ll, subLine, vsDraw, rcLine.right, tabWidthMinimumPixels);
-						std::unique_ptr<IScreenLineLayout> slLayout = surface->Layout(&screenLine);
-
-						const std::vector<Interval> intervals = slLayout->FindRangeIntervals(selectionStart, selectionEnd);
-						for (const Interval &interval : intervals) {
-							const XYPOSITION rcRight = interval.right + xStart;
-							const XYPOSITION rcLeft = interval.left + xStart;
-							const PRectangle rcSelection(rcLeft, rcLine.top, rcRight, rcLine.bottom);
-							surface->FillRectangleAligned(rcSelection, selectionBack);
-						}
+			const SelectionSegment portion = model.sel.Range(r).Intersect(virtualSpaceRange);
+			if (!portion.Empty()) {
+				const ColourAlpha selectionBack = SelectionBackground(
+					model, vsDraw, model.sel.RangeType(r));
+				const XYPOSITION spaceWidth = vsDraw.styles[ll->EndLineStyle()].spaceWidth;
+				if (model.BidirectionalEnabled()) {
+					const int selectionStart = static_cast<int>(portion.start.Position() - posLineStart - lineRange.start);
+					const int selectionEnd = static_cast<int>(portion.end.Position() - posLineStart - lineRange.start);
+
+					const ScreenLine screenLine(ll, subLine, vsDraw, rcLine.right, tabWidthMinimumPixels);
+					std::unique_ptr<IScreenLineLayout> slLayout = surface->Layout(&screenLine);
+
+					const std::vector<Interval> intervals = slLayout->FindRangeIntervals(selectionStart, selectionEnd);
+					for (const Interval &interval : intervals) {
+						const XYPOSITION rcRight = interval.right + xStart;
+						const XYPOSITION rcLeft = interval.left + xStart;
+						const PRectangle rcSelection(rcLeft, rcLine.top, rcRight, rcLine.bottom);
+						surface->FillRectangleAligned(rcSelection, selectionBack);
+					}
 
-						if (portion.end.VirtualSpace()) {
-							const XYPOSITION xStartVirtual = ll->positions[lineRange.end] -
-								static_cast<XYPOSITION>(subLineStart) + xStart;
-							PRectangle rcSegment = rcLine;
-							rcSegment.left = xStartVirtual + portion.start.VirtualSpace() * spaceWidth;
-							rcSegment.right = xStartVirtual + portion.end.VirtualSpace() * spaceWidth;
-							surface->FillRectangleAligned(rcSegment, selectionBack);
-						}
-					} else {
+					if (portion.end.VirtualSpace()) {
+						const XYPOSITION xStartVirtual = ll->positions[lineRange.end] -
+							static_cast<XYPOSITION>(subLineStart) + xStart;
 						PRectangle rcSegment = rcLine;
-						rcSegment.left = xStart + ll->positions[portion.start.Position() - posLineStart] -
-							static_cast<XYPOSITION>(subLineStart) + portion.start.VirtualSpace() * spaceWidth;
-						rcSegment.right = xStart + ll->positions[portion.end.Position() - posLineStart] -
-							static_cast<XYPOSITION>(subLineStart) + portion.end.VirtualSpace() * spaceWidth;
-						if ((ll->wrapIndent != 0) && (lineRange.start != 0)) {
-							if ((portion.start.Position() - posLineStart) == lineRange.start && model.sel.Range(r).ContainsCharacter(portion.start.Position() - 1))
-								rcSegment.left -= static_cast<int>(ll->wrapIndent); // indentation added to xStart was truncated to int, so we do the same here
-						}
-						rcSegment.left = (rcSegment.left > rcLine.left) ? rcSegment.left : rcLine.left;
-						rcSegment.right = (rcSegment.right < rcLine.right) ? rcSegment.right : rcLine.right;
-						if (rcSegment.right > rcLine.left)
-							surface->FillRectangleAligned(rcSegment, selectionBack);
+						rcSegment.left = xStartVirtual + portion.start.VirtualSpace() * spaceWidth;
+						rcSegment.right = xStartVirtual + portion.end.VirtualSpace() * spaceWidth;
+						surface->FillRectangleAligned(rcSegment, selectionBack);
 					}
+				} else {
+					PRectangle rcSegment = rcLine;
+					rcSegment.left = xStart + ll->positions[portion.start.Position() - posLineStart] -
+						static_cast<XYPOSITION>(subLineStart) + portion.start.VirtualSpace() * spaceWidth;
+					rcSegment.right = xStart + ll->positions[portion.end.Position() - posLineStart] -
+						static_cast<XYPOSITION>(subLineStart) + portion.end.VirtualSpace() * spaceWidth;
+					if ((ll->wrapIndent != 0) && (lineRange.start != 0)) {
+						if ((portion.start.Position() - posLineStart) == lineRange.start && model.sel.Range(r).ContainsCharacter(portion.start.Position() - 1))
+							rcSegment.left -= static_cast<int>(ll->wrapIndent); // indentation added to xStart was truncated to int, so we do the same here
+					}
+					rcSegment.left = (rcSegment.left > rcLine.left) ? rcSegment.left : rcLine.left;
+					rcSegment.right = (rcSegment.right < rcLine.right) ? rcSegment.right : rcLine.right;
+					if (rcSegment.right > rcLine.left)
+						surface->FillRectangleAligned(rcSegment, selectionBack);
 				}
 			}
 		}
@@ -1972,7 +1970,7 @@ void EditView::DrawForeground(Surface *surface, const EditModel &model, const Vi
 				}
 			}
 			const InSelection inSelection = hideSelection ? InSelection::inNone : model.sel.CharacterInSelection(iDoc);
-			const std::optional<ColourAlpha> selectionFore = SelectionForeground(vsDraw, inSelection);
+			const std::optional<ColourAlpha> selectionFore = SelectionForeground(model, vsDraw, inSelection);
 			if (selectionFore) {
 				textFore = *selectionFore;
 			}
@@ -2461,28 +2459,26 @@ void EditView::PaintText(Surface *surfaceWindow, const EditModel &model, PRectan
 void EditView::FillLineRemainder(Surface *surface, const EditModel &model, const ViewStyle &vsDraw, const LineLayout *ll,
 	Sci::Line line, PRectangle rcArea, int subLine) const {
 		InSelection eolInSelection = InSelection::inNone;
-		int alpha = SC_ALPHA_NOALPHA;
-		if ((!hideSelection) && (subLine == (ll->lines - 1))) {
-			eolInSelection = model.LineEndInSelection(line);
-			alpha = (eolInSelection == InSelection::inMain) ? vsDraw.selection.alpha : vsDraw.selection.additionalAlpha;
-		}
+	if ((!hideSelection) && (subLine == (ll->lines - 1))) {
+		eolInSelection = model.LineEndInSelection(line);
+	}
 
-		const std::optional<ColourAlpha> background = vsDraw.Background(model.pdoc->GetMark(line), model.caret.active, ll->containsCaret);
+	const std::optional<ColourAlpha> background = vsDraw.Background(model.pdoc->GetMark(line), model.caret.active, ll->containsCaret);
 
-		if (eolInSelection && vsDraw.selection.eolFilled && vsDraw.selection.colours.back && (line < model.pdoc->LinesTotal() - 1) && (alpha == SC_ALPHA_NOALPHA)) {
-			surface->FillRectangleAligned(rcArea, Fill(SelectionBackground(model, vsDraw, eolInSelection)));
+	if (eolInSelection && vsDraw.selection.eolFilled && (line < model.pdoc->LinesTotal() - 1) && (vsDraw.selection.layer == Layer::base)) {
+		surface->FillRectangleAligned(rcArea, Fill(SelectionBackground(model, vsDraw, eolInSelection).Opaque()));
+	} else {
+		if (background) {
+			surface->FillRectangleAligned(rcArea, Fill(*background));
+		} else if (vsDraw.styles[ll->styles[ll->numCharsInLine]].eolFilled) {
+			surface->FillRectangleAligned(rcArea, Fill(vsDraw.styles[ll->styles[ll->numCharsInLine]].back));
 		} else {
-			if (background) {
-				surface->FillRectangleAligned(rcArea, Fill(*background));
-			} else if (vsDraw.styles[ll->styles[ll->numCharsInLine]].eolFilled) {
-				surface->FillRectangleAligned(rcArea, Fill(vsDraw.styles[ll->styles[ll->numCharsInLine]].back));
-			} else {
-				surface->FillRectangleAligned(rcArea, Fill(vsDraw.styles[STYLE_DEFAULT].back));
-			}
-			if (eolInSelection && vsDraw.selection.eolFilled && vsDraw.selection.colours.back && (line < model.pdoc->LinesTotal() - 1) && (alpha != SC_ALPHA_NOALPHA)) {
-				surface->FillRectangleAligned(rcArea, ColourAlpha(SelectionBackground(model, vsDraw, eolInSelection), alpha));
-			}
+			surface->FillRectangleAligned(rcArea, Fill(vsDraw.styles[STYLE_DEFAULT].back));
 		}
+		if (eolInSelection && vsDraw.selection.eolFilled && (line < model.pdoc->LinesTotal() - 1) && (vsDraw.selection.layer == Layer::over)) {
+			surface->FillRectangleAligned(rcArea, SelectionBackground(model, vsDraw, eolInSelection));
+		}
+	}
 }
 
 // Space (3 space characters) between line numbers and text when printing.
@@ -2526,10 +2522,8 @@ Sci::Position EditView::FormatRange(bool draw, const Sci_RangeToFormat *pfr, Sur
 	// If this ever gets changed, cached pixmap would need to be recreated if technology != SC_TECHNOLOGY_DEFAULT
 	vsPrint.viewIndentationGuides = IndentView::none;
 	// Don't show the selection when printing
-	vsPrint.selection.colours.back.reset();
-	vsPrint.selection.colours.fore.reset();
-	vsPrint.selection.alpha = SC_ALPHA_NOALPHA;
-	vsPrint.selection.additionalAlpha = SC_ALPHA_NOALPHA;
+	vsPrint.elementColours.clear();
+	vsPrint.elementBaseColours.clear();
 	vsPrint.whitespaceColours.back.reset();
 	vsPrint.whitespaceColours.fore.reset();
 	vsPrint.caretLine.show = false;
diff --git a/src/Editor.cxx b/src/Editor.cxx
index 477173c6b..e6a31f11a 100644
--- a/src/Editor.cxx
+++ b/src/Editor.cxx
@@ -7417,25 +7417,38 @@ sptr_t Editor::WndProc(unsigned int iMessage, uptr_t wParam, sptr_t lParam) {
 		return LinesOnScreen();
 
 	case SCI_SETSELFORE:
-		vs.selection.colours.fore = OptionalColour(wParam, lParam);
-		vs.selection.additionalForeground = ColourAlpha::FromRGB(static_cast<int>(lParam));
+		vs.elementColours[SC_ELEMENT_SELECTION_TEXT] = OptionalColour(wParam, lParam);
+		vs.elementColours[SC_ELEMENT_SELECTION_ADDITIONAL_TEXT] = OptionalColour(wParam, lParam);
 		InvalidateStyleRedraw();
 		break;
 
 	case SCI_SETSELBACK:
-		vs.selection.colours.back = OptionalColour(wParam, lParam);
-		vs.selection.additionalBackground = ColourAlpha::FromRGB(static_cast<int>(lParam));
+		if (wParam) {
+			vs.SetElementRGB(SC_ELEMENT_SELECTION_BACK, static_cast<int>(lParam));
+			vs.SetElementRGB(SC_ELEMENT_SELECTION_ADDITIONAL_BACK, static_cast<int>(lParam));
+		} else {
+			vs.ResetElement(SC_ELEMENT_SELECTION_BACK);
+			vs.ResetElement(SC_ELEMENT_SELECTION_ADDITIONAL_BACK);
+		}
 		InvalidateStyleRedraw();
 		break;
 
-	case SCI_SETSELALPHA:
-		vs.selection.alpha = static_cast<int>(wParam);
-		vs.selection.additionalAlpha = static_cast<int>(wParam);
-		InvalidateStyleRedraw();
+	case SCI_SETSELALPHA: {
+			Layer layerNew = (wParam == SC_ALPHA_NOALPHA) ? Layer::base : Layer::over;
+			if (vs.selection.layer != layerNew) {
+			    vs.selection.layer = layerNew;
+			    UpdateBaseElements();
+			}
+			vs.SetElementAlpha(SC_ELEMENT_SELECTION_BACK, static_cast<int>(wParam));
+			vs.SetElementAlpha(SC_ELEMENT_SELECTION_ADDITIONAL_BACK, static_cast<int>(wParam));
+			InvalidateStyleRedraw();
+		}
 		break;
 
 	case SCI_GETSELALPHA:
-		return vs.selection.alpha;
+		if (vs.selection.layer == Layer::base)
+			return SC_ALPHA_NOALPHA;
+		return vs.ElementColour(SC_ELEMENT_SELECTION_BACK)->GetAlpha();
 
 	case SCI_GETSELEOLFILLED:
 		return vs.selection.eolFilled;
@@ -7455,13 +7468,24 @@ sptr_t Editor::WndProc(unsigned int iMessage, uptr_t wParam, sptr_t lParam) {
 		InvalidateStyleRedraw();
 		break;
 
+	case SCI_SETSELECTIONLAYER:
+		if (vs.selection.layer != static_cast<Layer>(wParam)) {
+			vs.selection.layer = static_cast<Layer>(wParam);
+			UpdateBaseElements();
+			InvalidateStyleRedraw();
+		}
+		break;
+
+	case SCI_GETSELECTIONLAYER:
+		return static_cast<sptr_t>(vs.selection.layer);
+
 	case SCI_SETCARETFORE:
-		vs.caret.colour = ColourAlpha::FromRGB(static_cast<int>(wParam));
+		vs.elementColours[SC_ELEMENT_CARET] = ColourAlpha::FromRGB(static_cast<int>(wParam));
 		InvalidateStyleRedraw();
 		break;
 
 	case SCI_GETCARETFORE:
-		return vs.caret.colour.OpaqueRGB();
+		return vs.ElementColour(SC_ELEMENT_CARET)->OpaqueRGB();
 
 	case SCI_SETCARETSTYLE:
 		if (wParam <= (CARETSTYLE_BLOCK | CARETSTYLE_OVERSTRIKE_BLOCK | CARETSTYLE_BLOCK_AFTER))
@@ -8418,30 +8442,32 @@ sptr_t Editor::WndProc(unsigned int iMessage, uptr_t wParam, sptr_t lParam) {
 		return virtualSpaceOptions;
 
 	case SCI_SETADDITIONALSELFORE:
-		vs.selection.additionalForeground = ColourAlpha::FromRGB(static_cast<int>(wParam));
+		vs.elementColours[SC_ELEMENT_SELECTION_ADDITIONAL_TEXT] = ColourAlpha::FromRGB(static_cast<int>(wParam));
 		InvalidateStyleRedraw();
 		break;
 
 	case SCI_SETADDITIONALSELBACK:
-		vs.selection.additionalBackground = ColourAlpha::FromRGB(static_cast<int>(wParam));
+		vs.SetElementRGB(SC_ELEMENT_SELECTION_ADDITIONAL_BACK, static_cast<int>(wParam));
 		InvalidateStyleRedraw();
 		break;
 
 	case SCI_SETADDITIONALSELALPHA:
-		vs.selection.additionalAlpha = static_cast<int>(wParam);
+		vs.SetElementAlpha(SC_ELEMENT_SELECTION_ADDITIONAL_BACK, static_cast<int>(wParam));
 		InvalidateStyleRedraw();
 		break;
 
 	case SCI_GETADDITIONALSELALPHA:
-		return vs.selection.additionalAlpha;
+		if (vs.selection.layer == Layer::base)
+			return SC_ALPHA_NOALPHA;
+		return vs.ElementColour(SC_ELEMENT_SELECTION_ADDITIONAL_BACK)->GetAlpha();
 
 	case SCI_SETADDITIONALCARETFORE:
-		vs.caret.additionalColour = ColourAlpha::FromRGB(static_cast<int>(wParam));
+		vs.elementColours[SC_ELEMENT_CARET_ADDITIONAL] = ColourAlpha::FromRGB(static_cast<int>(wParam));
 		InvalidateStyleRedraw();
 		break;
 
 	case SCI_GETADDITIONALCARETFORE:
-		return vs.caret.additionalColour.OpaqueRGB();
+		return vs.ElementColour(SC_ELEMENT_CARET_ADDITIONAL)->OpaqueRGB();
 
 	case SCI_ROTATESELECTION:
 		sel.RotateMain();
diff --git a/src/ViewStyle.cxx b/src/ViewStyle.cxx
index 16701983e..ed08ad6ce 100644
--- a/src/ViewStyle.cxx
+++ b/src/ViewStyle.cxx
@@ -196,13 +196,17 @@ void ViewStyle::Init(size_t stylesSize_) {
 	spaceWidth = 8;
 	tabWidth = spaceWidth * 8;
 
-	selection.colours.fore.reset();
-	selection.colours.back = ColourAlpha(0xc0, 0xc0, 0xc0);
-	selection.additionalForeground = ColourAlpha(0xff, 0, 0);
-	selection.additionalBackground = ColourAlpha(0xd7, 0xd7, 0xd7);
-	selection.background2 = ColourAlpha(0xb0, 0xb0, 0xb0);
-	selection.alpha = SC_ALPHA_NOALPHA;
-	selection.additionalAlpha = SC_ALPHA_NOALPHA;
+	// Default is for no selection foregrounds
+	elementColours.erase(SC_ELEMENT_SELECTION_TEXT);
+	elementColours.erase(SC_ELEMENT_SELECTION_ADDITIONAL_TEXT);
+	elementColours.erase(SC_ELEMENT_SELECTION_SECONDARY_TEXT);
+	elementColours.erase(SC_ELEMENT_SELECTION_NO_FOCUS_TEXT);
+	// Shades of grey for selection backgrounds
+	elementBaseColours[SC_ELEMENT_SELECTION_BACK] = ColourAlpha(0xc0, 0xc0, 0xc0, 0xff);
+	elementBaseColours[SC_ELEMENT_SELECTION_ADDITIONAL_BACK] = ColourAlpha(0xd7, 0xd7, 0xd7, 0xff);
+	elementBaseColours[SC_ELEMENT_SELECTION_SECONDARY_BACK] = ColourAlpha(0xb0, 0xb0, 0xb0, 0xff);
+	elementBaseColours[SC_ELEMENT_SELECTION_NO_FOCUS_BACK] = ColourAlpha(0x80, 0x80, 0x80, 0x3f);
+	selection.layer = Layer::base;
 	selection.eolFilled = false;
 
 	foldmarginColour.reset();
@@ -217,8 +221,9 @@ void ViewStyle::Init(size_t stylesSize_) {
 	styles[STYLE_LINENUMBER].fore = ColourAlpha(0, 0, 0);
 	styles[STYLE_LINENUMBER].back = Platform::Chrome();
 
-	caret.colour = ColourAlpha(0, 0, 0);
-	caret.additionalColour = ColourAlpha(0x7f, 0x7f, 0x7f);
+	elementBaseColours[SC_ELEMENT_CARET] = ColourAlpha(0, 0, 0);
+	elementBaseColours[SC_ELEMENT_CARET_ADDITIONAL] = ColourAlpha(0x7f, 0x7f, 0x7f);
+	elementBaseColours[SC_ELEMENT_CARET_SECONDARY] = ColourAlpha(0, 0, 0, 0x40);
 	caret.style = CARETSTYLE_LINE;
 	caret.width = 1;
 
@@ -483,12 +488,15 @@ std::optional<ColourAlpha> ViewStyle::Background(int marksOfLine, bool caretActi
 }
 
 bool ViewStyle::SelectionBackgroundDrawn() const noexcept {
-	return selection.colours.back &&
-		((selection.alpha == SC_ALPHA_NOALPHA) || (selection.additionalAlpha == SC_ALPHA_NOALPHA));
+	return selection.layer == Layer::base;
 }
 
 bool ViewStyle::SelectionTextDrawn() const {
-	return selection.colours.fore.has_value();
+	return
+		ElementIsSet(SC_ELEMENT_SELECTION_TEXT) ||
+		ElementIsSet(SC_ELEMENT_SELECTION_ADDITIONAL_TEXT) ||
+		ElementIsSet(SC_ELEMENT_SELECTION_SECONDARY_TEXT) ||
+		ElementIsSet(SC_ELEMENT_SELECTION_NO_FOCUS_TEXT);
 }
 
 bool ViewStyle::WhitespaceBackgroundDrawn() const noexcept {
@@ -540,6 +548,16 @@ void ViewStyle::ResetElement(int element) {
 	elementColours.erase(element);
 }
 
+void ViewStyle::SetElementRGB(int element, int rgb) {
+	const ColourAlpha current = ElementColour(element).value_or(ColourAlpha(0, 0, 0, 0));
+	elementColours[element] = ColourAlpha(ColourAlpha(rgb), current.GetAlpha());
+}
+
+void ViewStyle::SetElementAlpha(int element, int alpha) {
+	const ColourAlpha current = ElementColour(element).value_or(ColourAlpha(0, 0, 0, 0));
+	elementColours[element] = ColourAlpha(current, std::min(alpha, 0xff));
+}
+
 bool ViewStyle::ElementIsSet(int element) const {
 	ElementMap::const_iterator search = elementColours.find(element);
 	if (search != elementColours.end()) {
diff --git a/src/ViewStyle.h b/src/ViewStyle.h
index a9fe58131..6aab53f64 100644
--- a/src/ViewStyle.h
+++ b/src/ViewStyle.h
@@ -63,18 +63,11 @@ struct ForeBackColours {
 	std::optional<ColourAlpha> back;
 };
 
+enum class Layer { base=0, over=10 };
+
 struct SelectionAppearance {
-	// Colours of main selection
-	ForeBackColours colours;
-	// Colours of additional (non-main) selections
-	ColourAlpha additionalForeground;
-	ColourAlpha additionalBackground;
-	// Background colour on X when not primary selection
-	ColourAlpha background2;
-	// Translucency. SC_ALPHA_NOALPHA: draw selection background beneath text
-	int alpha;
-	// Translucency of additional selections
-	int additionalAlpha;
+	// Whether to draw on base layer or over text
+	Layer layer;
 	// Draw selection past line end characters up to right border
 	bool eolFilled;
 };
@@ -93,10 +86,6 @@ struct CaretLineAppearance {
 };
 
 struct CaretAppearance {
-	// Colour of caret
-	ColourAlpha colour;
-	// Colour of additional (non-main) carets
-	ColourAlpha additionalColour;
 	// Line, block, over-strike bar ... 
 	int style;
 	// Width in pixels
@@ -245,6 +234,8 @@ public:
 	std::optional<ColourAlpha> ElementColour(int element) const;
 	bool ElementAllowsTranslucent(int element) const;
 	void ResetElement(int element);
+	void SetElementRGB(int element, int rgb);
+	void SetElementAlpha(int element, int alpha);
 	bool ElementIsSet(int element) const;
 	bool SetElementBase(int element, ColourAlpha colour);