Change Font to an interface and stop using FontID. Fonts are shared and

reference counted using std::shared_ptr. This optimizes memory and reduces
potential for allocation bugs.

15 files changed, 60 insertions, 111 deletions

diff --git a/src/CallTip.cxx b/src/CallTip.cxx
index 667e41c96..e6bfc2b7e 100644
--- a/src/CallTip.cxx
+++ b/src/CallTip.cxx
@@ -67,7 +67,6 @@ CallTip::CallTip() noexcept {
 }
 
 CallTip::~CallTip() {
-	font.Release();
 	wCallTip.Destroy();
 }
 
@@ -168,11 +167,11 @@ int CallTip::DrawChunk(Surface *surface, int x, std::string_view sv,
 			xEnd = NextTabPos(x);
 		} else {
 			const std::string_view segText = sv.substr(startSeg, endSeg - startSeg);
-			xEnd = x + static_cast<int>(std::lround(surface->WidthText(font, segText)));
+			xEnd = x + static_cast<int>(std::lround(surface->WidthText(font.get(), segText)));
 			if (draw) {
 				rcClient.left = static_cast<XYPOSITION>(x);
 				rcClient.right = static_cast<XYPOSITION>(xEnd);
-				surface->DrawTextTransparent(rcClient, font, static_cast<XYPOSITION>(ytext),
+				surface->DrawTextTransparent(rcClient, font.get(), static_cast<XYPOSITION>(ytext),
 									segText, asHighlight ? colourSel : colourUnSel);
 			}
 		}
@@ -189,12 +188,12 @@ int CallTip::PaintContents(Surface *surfaceWindow, bool draw) {
 	PRectangle rcClient(1.0f, 1.0f, rcClientSize.right - 1, rcClientSize.bottom - 1);
 
 	// To make a nice small call tip window, it is only sized to fit most normal characters without accents
-	const int ascent = static_cast<int>(std::round(surfaceWindow->Ascent(font) - surfaceWindow->InternalLeading(font)));
+	const int ascent = static_cast<int>(std::round(surfaceWindow->Ascent(font.get()) - surfaceWindow->InternalLeading(font.get())));
 
 	// For each line...
 	// Draw the definition in three parts: before highlight, highlighted, after highlight
 	int ytext = static_cast<int>(rcClient.top) + ascent + 1;
-	rcClient.bottom = ytext + surfaceWindow->Descent(font) + 1;
+	rcClient.bottom = ytext + surfaceWindow->Descent(font.get()) + 1;
 	std::string_view remaining(val);
 	int maxWidth = 0;
 	size_t lineStart = 0;
@@ -286,7 +285,7 @@ PRectangle CallTip::CallTipStart(Sci::Position pos, Point pt, int textHeight, co
 	posStartCallTip = pos;
 	const XYPOSITION deviceHeight = static_cast<XYPOSITION>(surfaceMeasure->DeviceHeightFont(size));
 	const FontParameters fp(faceName, deviceHeight / SC_FONT_SIZE_MULTIPLIER, SC_WEIGHT_NORMAL, false, 0, technology, characterSet);
-	font.Create(fp);
+	font = Font::Allocate(fp);
 	// Look for multiple lines in the text
 	// Only support \n here - simply means container must avoid \r!
 	const int numLines = 1 + static_cast<int>(std::count(val.begin(), val.end(), '\n'));
@@ -294,12 +293,12 @@ PRectangle CallTip::CallTipStart(Sci::Position pos, Point pt, int textHeight, co
 	rectDown = PRectangle(0,0,0,0);
 	offsetMain = insetX;            // changed to right edge of any arrows
 	const int width = PaintContents(surfaceMeasure.get(), false) + insetX;
-	lineHeight = static_cast<int>(std::lround(surfaceMeasure->Height(font)));
+	lineHeight = static_cast<int>(std::lround(surfaceMeasure->Height(font.get())));
 
 	// The returned
 	// rectangle is aligned to the right edge of the last arrow encountered in
 	// the tip text, else to the tip text left edge.
-	const int height = lineHeight * numLines - static_cast<int>(surfaceMeasure->InternalLeading(font)) + borderHeight * 2;
+	const int height = lineHeight * numLines - static_cast<int>(surfaceMeasure->InternalLeading(font.get())) + borderHeight * 2;
 	if (above) {
 		return PRectangle(pt.x - offsetMain, pt.y - verticalOffset - height, pt.x + width - offsetMain, pt.y - verticalOffset);
 	} else {
diff --git a/src/CallTip.h b/src/CallTip.h
index 562b24f9d..6cc89d3a5 100644
--- a/src/CallTip.h
+++ b/src/CallTip.h
@@ -24,7 +24,7 @@ struct Chunk {
 class CallTip {
 	Chunk highlight;    // character offset to start and end of highlighted text
 	std::string val;
-	Font font;
+	std::shared_ptr<Font> font;
 	PRectangle rectUp;      // rectangle of last up angle in the tip
 	PRectangle rectDown;    // rectangle of last down arrow in the tip
 	int lineHeight;         // vertical line spacing
diff --git a/src/EditView.cxx b/src/EditView.cxx
index 87d8134c6..fcb747d21 100644
--- a/src/EditView.cxx
+++ b/src/EditView.cxx
@@ -90,7 +90,7 @@ static int WidthStyledText(Surface *surface, const ViewStyle &vs, int styleOffse
 		size_t endSegment = start;
 		while ((endSegment + 1 < len) && (styles[endSegment + 1] == style))
 			endSegment++;
-		FontAlias fontText = vs.styles[style + styleOffset].font;
+		const Font *fontText = vs.styles[style + styleOffset].font.get();
 		const std::string_view sv(text + start, endSegment - start + 1);
 		width += static_cast<int>(surface->WidthText(fontText, sv));
 		start = endSegment + 1;
@@ -107,7 +107,7 @@ int WidestLineWidth(Surface *surface, const ViewStyle &vs, int styleOffset, cons
 		if (st.multipleStyles) {
 			widthSubLine = WidthStyledText(surface, vs, styleOffset, st.text + start, st.styles + start, lenLine);
 		} else {
-			FontAlias fontText = vs.styles[styleOffset + st.style].font;
+			const Font *fontText = vs.styles[styleOffset + st.style].font.get();
 			const std::string_view text(st.text + start, lenLine);
 			widthSubLine = static_cast<int>(surface->WidthText(fontText, text));
 		}
@@ -120,7 +120,7 @@ int WidestLineWidth(Surface *surface, const ViewStyle &vs, int styleOffset, cons
 
 void DrawTextNoClipPhase(Surface *surface, PRectangle rc, const Style &style, XYPOSITION ybase,
 	std::string_view text, DrawPhase phase) {
-	FontAlias fontText = style.font;
+	const Font *fontText = style.font.get();
 	if (phase & drawBack) {
 		if (phase & drawText) {
 			// Drawing both
@@ -146,7 +146,7 @@ void DrawStyledText(Surface *surface, const ViewStyle &vs, int styleOffset, PRec
 			while (end < length - 1 && st.styles[start + end + 1] == style)
 				end++;
 			style += styleOffset;
-			FontAlias fontText = vs.styles[style].font;
+			const Font *fontText = vs.styles[style].font.get();
 			const std::string_view text(st.text + start + i, end - i + 1);
 			const int width = static_cast<int>(surface->WidthText(fontText, text));
 			PRectangle rcSegment = rcText;
@@ -601,9 +601,9 @@ void EditView::UpdateBidiData(const EditModel &model, const ViewStyle &vstyle, L
 	if (model.BidirectionalEnabled()) {
 		ll->EnsureBidiData();
 		for (int stylesInLine = 0; stylesInLine < ll->numCharsInLine; stylesInLine++) {
-			ll->bidiData->stylesFonts[stylesInLine].MakeAlias(vstyle.styles[ll->styles[stylesInLine]].font);
+			ll->bidiData->stylesFonts[stylesInLine] = vstyle.styles[ll->styles[stylesInLine]].font;
 		}
-		ll->bidiData->stylesFonts[ll->numCharsInLine].ClearFont();
+		ll->bidiData->stylesFonts[ll->numCharsInLine].reset();
 
 		for (int charsInLine = 0; charsInLine < ll->numCharsInLine; charsInLine++) {
 			const int charWidth = UTF8DrawBytes(reinterpret_cast<unsigned char *>(&ll->chars[charsInLine]), ll->numCharsInLine - charsInLine);
@@ -877,7 +877,7 @@ static void DrawTextBlob(Surface *surface, const ViewStyle &vsDraw, PRectangle r
 	if (fillBackground) {
 		surface->FillRectangle(rcSegment, textBack);
 	}
-	FontAlias ctrlCharsFont = vsDraw.styles[STYLE_CONTROLCHAR].font;
+	const Font *ctrlCharsFont = vsDraw.styles[STYLE_CONTROLCHAR].font.get();
 	const int normalCharHeight = static_cast<int>(std::ceil(vsDraw.styles[STYLE_CONTROLCHAR].capitalHeight));
 	PRectangle rcCChar = rcSegment;
 	rcCChar.left = rcCChar.left + 1;
@@ -1202,7 +1202,7 @@ void EditView::DrawFoldDisplayText(Surface *surface, const EditModel &model, con
 
 	PRectangle rcSegment = rcLine;
 	const std::string_view foldDisplayText(text);
-	FontAlias fontText = vsDraw.styles[STYLE_FOLDDISPLAYTEXT].font;
+	const Font *fontText = vsDraw.styles[STYLE_FOLDDISPLAYTEXT].font.get();
 	const int widthFoldDisplayText = static_cast<int>(surface->WidthText(fontText, foldDisplayText));
 
 	int eolInSelection = 0;
@@ -1300,7 +1300,7 @@ void EditView::DrawEOLAnnotationText(Surface *surface, const EditModel &model, c
 	const size_t style = stEOLAnnotation.style + vsDraw.eolAnnotationStyleOffset;
 
 	PRectangle rcSegment = rcLine;
-	FontAlias fontText = vsDraw.styles[style].font;
+	const Font *fontText = vsDraw.styles[style].font.get();
 	const int widthEOLAnnotationText = static_cast<int>(surface->WidthText(fontText, eolAnnotationText));
 
 	const XYPOSITION spaceWidth = vsDraw.styles[ll->EndLineStyle()].spaceWidth;
@@ -1493,7 +1493,7 @@ static void DrawBlockCaret(Surface *surface, const EditModel &model, const ViewS
 	// This character is where the caret block is, we override the colours
 	// (inversed) for drawing the caret here.
 	const int styleMain = ll->styles[offsetFirstChar];
-	FontAlias fontText = vsDraw.styles[styleMain].font;
+	const Font *fontText = vsDraw.styles[styleMain].font.get();
 	const std::string_view text(&ll->chars[offsetFirstChar], numCharsToDraw);
 	surface->DrawTextClipped(rcCaret, fontText,
 		rcCaret.top + vsDraw.maxAscent, text, vsDraw.styles[styleMain].back,
@@ -1883,7 +1883,7 @@ void EditView::DrawForeground(Surface *surface, const EditModel &model, const Vi
 		if (rcSegment.Intersects(rcLine)) {
 			const int styleMain = ll->styles[i];
 			ColourDesired textFore = vsDraw.styles[styleMain].fore;
-			FontAlias textFont = vsDraw.styles[styleMain].font;
+			const Font *textFont = vsDraw.styles[styleMain].font.get();
 			//hotspot foreground
 			const bool inHotspot = (ll->hotspot.Valid()) && ll->hotspot.ContainsCharacter(iDoc);
 			if (inHotspot) {
@@ -1961,7 +1961,7 @@ void EditView::DrawForeground(Surface *surface, const EditModel &model, const Vi
 						// Using one font for all control characters so it can be controlled independently to ensure
 						// the box goes around the characters tightly. Seems to be no way to work out what height
 						// is taken by an individual character - internal leading gives varying results.
-						FontAlias ctrlCharsFont = vsDraw.styles[STYLE_CONTROLCHAR].font;
+						const Font *ctrlCharsFont = vsDraw.styles[STYLE_CONTROLCHAR].font.get();
 						const char cc[2] = { static_cast<char>(vsDraw.controlCharSymbol), '\0' };
 						surface->DrawTextNoClip(rcSegment, ctrlCharsFont,
 							rcSegment.top + vsDraw.maxAscent,
@@ -2509,7 +2509,7 @@ Sci::Position EditView::FormatRange(bool draw, const Sci_RangeToFormat *pfr, Sur
 	// Determining width must happen after fonts have been realised in Refresh
 	int lineNumberWidth = 0;
 	if (lineNumberIndex >= 0) {
-		lineNumberWidth = static_cast<int>(surfaceMeasure->WidthText(vsPrint.styles[STYLE_LINENUMBER].font,
+		lineNumberWidth = static_cast<int>(surfaceMeasure->WidthText(vsPrint.styles[STYLE_LINENUMBER].font.get(),
 			"99999" lineNumberPrintSpace));
 		vsPrint.ms[lineNumberIndex].width = lineNumberWidth;
 		vsPrint.Refresh(*surfaceMeasure, model.pdoc->tabInChars);	// Recalculate fixedColumnWidth
@@ -2589,9 +2589,9 @@ Sci::Position EditView::FormatRange(bool draw, const Sci_RangeToFormat *pfr, Sur
 			rcNumber.right = rcNumber.left + lineNumberWidth;
 			// Right justify
 			rcNumber.left = rcNumber.right - surfaceMeasure->WidthText(
-				vsPrint.styles[STYLE_LINENUMBER].font, number);
+				vsPrint.styles[STYLE_LINENUMBER].font.get(), number);
 			surface->FlushCachedState();
-			surface->DrawTextNoClip(rcNumber, vsPrint.styles[STYLE_LINENUMBER].font,
+			surface->DrawTextNoClip(rcNumber, vsPrint.styles[STYLE_LINENUMBER].font.get(),
 				static_cast<XYPOSITION>(ypos + vsPrint.maxAscent), number,
 				vsPrint.styles[STYLE_LINENUMBER].fore,
 				vsPrint.styles[STYLE_LINENUMBER].back);
diff --git a/src/Editor.cxx b/src/Editor.cxx
index f9bf5a582..7fa790469 100644
--- a/src/Editor.cxx
+++ b/src/Editor.cxx
@@ -1829,7 +1829,7 @@ long Editor::TextWidth(uptr_t style, const char *text) {
 	RefreshStyleData();
 	AutoSurface surface(this);
 	if (surface) {
-		return std::lround(surface->WidthText(vs.styles[style].font, text));
+		return std::lround(surface->WidthText(vs.styles[style].font.get(), text));
 	} else {
 		return 1;
 	}
diff --git a/src/LineMarker.cxx b/src/LineMarker.cxx
index 286f334f5..861ae58aa 100644
--- a/src/LineMarker.cxx
+++ b/src/LineMarker.cxx
@@ -111,7 +111,7 @@ static void DrawMinus(Surface *surface, int centreX, int centreY, int armSize, C
 	surface->FillRectangle(rcH, fore);
 }
 
-void LineMarker::Draw(Surface *surface, PRectangle &rcWhole, Font &fontForCharacter, FoldPart part, int marginStyle) const {
+void LineMarker::Draw(Surface *surface, PRectangle &rcWhole, const Font *fontForCharacter, FoldPart part, int marginStyle) const {
 	if (customDraw) {
 		customDraw(surface, rcWhole, fontForCharacter, static_cast<int>(part), marginStyle, this);
 		return;
diff --git a/src/LineMarker.h b/src/LineMarker.h
index 4173f065e..468c53f13 100644
--- a/src/LineMarker.h
+++ b/src/LineMarker.h
@@ -13,7 +13,7 @@ namespace Scintilla {
 class XPM;
 class RGBAImage;
 
-typedef void (*DrawLineMarkerFn)(Surface *surface, PRectangle &rcWhole, Font &fontForCharacter, int tFold, int marginStyle, const void *lineMarker);
+typedef void (*DrawLineMarkerFn)(Surface *surface, PRectangle &rcWhole, const Font *fontForCharacter, int tFold, int marginStyle, const void *lineMarker);
 
 /**
  */
@@ -44,7 +44,7 @@ public:
 	void SetXPM(const char *textForm);
 	void SetXPM(const char *const *linesForm);
 	void SetRGBAImage(Point sizeRGBAImage, float scale, const unsigned char *pixelsRGBAImage);
-	void Draw(Surface *surface, PRectangle &rcWhole, Font &fontForCharacter, FoldPart part, int marginStyle) const;
+	void Draw(Surface *surface, PRectangle &rcWhole, const Font *fontForCharacter, FoldPart part, int marginStyle) const;
 };
 
 }
diff --git a/src/MarginView.cxx b/src/MarginView.cxx
index d2fb5f77d..27b057bd4 100644
--- a/src/MarginView.cxx
+++ b/src/MarginView.cxx
@@ -188,7 +188,7 @@ void MarginView::PaintMargin(Surface *surface, Sci::Line topLine, PRectangle rc,
 		rcSelMargin.bottom = rc.bottom;
 
 	const Point ptOrigin = model.GetVisibleOriginInMain();
-	FontAlias fontLineNumber = vs.styles[STYLE_LINENUMBER].font;
+	const Font *fontLineNumber = vs.styles[STYLE_LINENUMBER].font.get();
 	for (size_t margin = 0; margin < vs.ms.size(); margin++) {
 		if (vs.ms[margin].width > 0) {
 
diff --git a/src/Platform.h b/src/Platform.h
index 778c9a810..cd096af6b 100644
--- a/src/Platform.h
+++ b/src/Platform.h
@@ -81,7 +81,6 @@ namespace Scintilla {
 // Underlying the implementation of the platform classes are platform specific types.
 // Sometimes these need to be passed around by client code so they are defined here
 
-typedef void *FontID;
 typedef void *SurfaceID;
 typedef void *WindowID;
 typedef void *MenuID;
@@ -124,25 +123,16 @@ struct FontParameters {
 };
 
 class Font {
-protected:
-	FontID fid;
 public:
-	Font() noexcept;
+	Font() noexcept=default;
 	// Deleted so Font objects can not be copied
 	Font(const Font &) = delete;
 	Font(Font &&) = delete;
 	Font &operator=(const Font &) = delete;
 	Font &operator=(Font &&) = delete;
-	virtual ~Font();
-
-	virtual void Create(const FontParameters &fp);
-	virtual void Release();
+	virtual ~Font()=default;
 
-	FontID GetID() const noexcept { return fid; }
-	// Alias another font - caller guarantees not to Release
-	void SetID(FontID fid_) noexcept { fid = fid_; }
-	friend class Surface;
-	friend class SurfaceImpl;
+	static std::shared_ptr<Font> Allocate(const FontParameters &fp);
 };
 
 class IScreenLine {
@@ -206,16 +196,16 @@ public:
 
 	virtual std::unique_ptr<IScreenLineLayout> Layout(const IScreenLine *screenLine) = 0;
 
-	virtual void DrawTextNoClip(PRectangle rc, Font &font_, XYPOSITION ybase, std::string_view text, ColourDesired fore, ColourDesired back) = 0;
-	virtual void DrawTextClipped(PRectangle rc, Font &font_, XYPOSITION ybase, std::string_view text, ColourDesired fore, ColourDesired back) = 0;
-	virtual void DrawTextTransparent(PRectangle rc, Font &font_, XYPOSITION ybase, std::string_view text, ColourDesired fore) = 0;
-	virtual void MeasureWidths(Font &font_, std::string_view text, XYPOSITION *positions) = 0;
-	virtual XYPOSITION WidthText(Font &font_, std::string_view text) = 0;
-	virtual XYPOSITION Ascent(Font &font_)=0;
-	virtual XYPOSITION Descent(Font &font_)=0;
-	virtual XYPOSITION InternalLeading(Font &font_)=0;
-	virtual XYPOSITION Height(Font &font_)=0;
-	virtual XYPOSITION AverageCharWidth(Font &font_)=0;
+	virtual void DrawTextNoClip(PRectangle rc, const Font *font_, XYPOSITION ybase, std::string_view text, ColourDesired fore, ColourDesired back) = 0;
+	virtual void DrawTextClipped(PRectangle rc, const Font *font_, XYPOSITION ybase, std::string_view text, ColourDesired fore, ColourDesired back) = 0;
+	virtual void DrawTextTransparent(PRectangle rc, const Font *font_, XYPOSITION ybase, std::string_view text, ColourDesired fore) = 0;
+	virtual void MeasureWidths(const Font *font_, std::string_view text, XYPOSITION *positions) = 0;
+	virtual XYPOSITION WidthText(const Font *font_, std::string_view text) = 0;
+	virtual XYPOSITION Ascent(const Font *font_)=0;
+	virtual XYPOSITION Descent(const Font *font_)=0;
+	virtual XYPOSITION InternalLeading(const Font *font_)=0;
+	virtual XYPOSITION Height(const Font *font_)=0;
+	virtual XYPOSITION AverageCharWidth(const Font *font_)=0;
 
 	virtual void SetClip(PRectangle rc)=0;
 	virtual void FlushCachedState()=0;
@@ -255,7 +245,7 @@ public:
 	void Show(bool show=true);
 	void InvalidateAll();
 	void InvalidateRectangle(PRectangle rc);
-	virtual void SetFont(Font &font);
+	virtual void SetFont(const Font *font);
 	enum Cursor { cursorInvalid, cursorText, cursorArrow, cursorUp, cursorWait, cursorHoriz, cursorVert, cursorReverseArrow, cursorHand };
 	void SetCursor(Cursor curs);
 	PRectangle GetMonitorRect(Point pt);
@@ -286,7 +276,7 @@ public:
 	~ListBox() override;
 	static ListBox *Allocate();
 
-	void SetFont(Font &font) override =0;
+	void SetFont(const Font *font) override =0;
 	virtual void Create(Window &parent, int ctrlID, Point location, int lineHeight_, bool unicodeMode_, int technology_)=0;
 	virtual void SetAverageCharWidth(int width)=0;
 	virtual void SetVisibleRows(int rows)=0;
diff --git a/src/PositionCache.cxx b/src/PositionCache.cxx
index 55af2dabb..8665c19be 100644
--- a/src/PositionCache.cxx
+++ b/src/PositionCache.cxx
@@ -342,7 +342,7 @@ XYPOSITION ScreenLine::TabWidthMinimumPixels() const {
 }
 
 const Font *ScreenLine::FontOfPosition(size_t position) const {
-	return &ll->bidiData->stylesFonts[start + position];
+	return ll->bidiData->stylesFonts[start + position].get();
 }
 
 XYPOSITION ScreenLine::RepresentationWidth(size_t position) const {
@@ -795,7 +795,7 @@ void PositionCache::MeasureWidths(Surface *surface, const ViewStyle &vstyle, uns
 			probe = probe2;
 		}
 	}
-	FontAlias fontStyle = vstyle.styles[styleNumber].font;
+	const Font *fontStyle = vstyle.styles[styleNumber].font.get();
 	if (len > BreakFinder::lengthStartSubdivision) {
 		// Break up into segments
 		unsigned int startSegment = 0;
diff --git a/src/PositionCache.h b/src/PositionCache.h
index 7573a2dc3..8968092e7 100644
--- a/src/PositionCache.h
+++ b/src/PositionCache.h
@@ -46,7 +46,7 @@ enum PointEnd {
 
 class BidiData {
 public:
-	std::vector<FontAlias> stylesFonts;
+	std::vector<std::shared_ptr<Font>> stylesFonts;
 	std::vector<XYPOSITION> widthReprs;
 	void Resize(size_t maxLineLength_);
 };
diff --git a/src/ScintillaBase.cxx b/src/ScintillaBase.cxx
index 4830357ed..b46a2207a 100644
--- a/src/ScintillaBase.cxx
+++ b/src/ScintillaBase.cxx
@@ -289,7 +289,7 @@ void ScintillaBase::AutoCompleteStart(Sci::Position lenEntered, const char *list
 	rcac.right = rcac.left + widthLB;
 	rcac.bottom = static_cast<XYPOSITION>(std::min(static_cast<int>(rcac.top) + heightLB, static_cast<int>(rcPopupBounds.bottom)));
 	ac.lb->SetPositionRelative(rcac, &wMain);
-	ac.lb->SetFont(vs.styles[STYLE_DEFAULT].font);
+	ac.lb->SetFont(vs.styles[STYLE_DEFAULT].font.get());
 	const unsigned int aveCharWidth = static_cast<unsigned int>(vs.styles[STYLE_DEFAULT].aveCharWidth);
 	ac.lb->SetAverageCharWidth(aveCharWidth);
 	ac.lb->SetDelegate(this);
diff --git a/src/Style.cxx b/src/Style.cxx
index 5a3628e8f..85ac58738 100644
--- a/src/Style.cxx
+++ b/src/Style.cxx
@@ -18,31 +18,6 @@
 
 using namespace Scintilla;
 
-FontAlias::FontAlias() noexcept {
-}
-
-FontAlias::FontAlias(const FontAlias &other) noexcept : Font() {
-	SetID(other.fid);
-}
-
-FontAlias::FontAlias(FontAlias &&other) noexcept : Font() {
-	SetID(other.fid);
-	other.ClearFont();
-}
-
-FontAlias::~FontAlias() {
-	SetID(FontID{});
-	// ~Font will not release the actual font resource since it is now 0
-}
-
-void FontAlias::MakeAlias(const Font &fontOrigin) noexcept {
-	SetID(fontOrigin.GetID());
-}
-
-void FontAlias::ClearFont() noexcept {
-	SetID(FontID{});
-}
-
 bool FontSpecification::operator==(const FontSpecification &other) const noexcept {
 	return fontName == other.fontName &&
 	       weight == other.weight &&
@@ -148,7 +123,7 @@ void Style::Clear(ColourDesired fore_, ColourDesired back_, int size_,
 	visible = visible_;
 	changeable = changeable_;
 	hotspot = hotspot_;
-	font.ClearFont();
+	font.reset();
 	FontMeasurements::ClearMeasurements();
 }
 
@@ -169,7 +144,7 @@ void Style::ClearTo(const Style &source) noexcept {
 	    source.hotspot);
 }
 
-void Style::Copy(const Font &font_, const FontMeasurements &fm_) noexcept {
-	font.MakeAlias(font_);
+void Style::Copy(std::shared_ptr<Font> font_, const FontMeasurements &fm_) noexcept {
+	font = std::move(font_);
 	(FontMeasurements &)(*this) = fm_;
 }
diff --git a/src/Style.h b/src/Style.h
index 071d752ca..769386359 100644
--- a/src/Style.h
+++ b/src/Style.h
@@ -29,20 +29,6 @@ struct FontSpecification {
 	bool operator<(const FontSpecification &other) const noexcept;
 };
 
-// Just like Font but only has a copy of the FontID so should not delete it
-class FontAlias : public Font {
-public:
-	FontAlias() noexcept;
-	// FontAlias objects can be copy or move constructed but not be assigned
-	FontAlias(const FontAlias &) noexcept;
-	FontAlias(FontAlias &&) noexcept;
-	FontAlias &operator=(const FontAlias &) = delete;
-	FontAlias &operator=(FontAlias &&) = delete;
-	~FontAlias() override;
-	void MakeAlias(const Font &fontOrigin) noexcept;
-	void ClearFont() noexcept;
-};
-
 struct FontMeasurements {
 	unsigned int ascent;
 	unsigned int descent;
@@ -68,7 +54,7 @@ public:
 	bool changeable;
 	bool hotspot;
 
-	FontAlias font;
+	std::shared_ptr<Font> font;
 
 	Style();
 	Style(const Style &source) noexcept;
@@ -83,7 +69,7 @@ public:
 	           bool underline_, ecaseForced caseForce_,
 	           bool visible_, bool changeable_, bool hotspot_) noexcept;
 	void ClearTo(const Style &source) noexcept;
-	void Copy(const Font &font_, const FontMeasurements &fm_) noexcept;
+	void Copy(std::shared_ptr<Font> font_, const FontMeasurements &fm_) noexcept;
 	bool IsProtected() const noexcept { return !(changeable && visible);}
 };
 
diff --git a/src/ViewStyle.cxx b/src/ViewStyle.cxx
index d05e82749..0a3451026 100644
--- a/src/ViewStyle.cxx
+++ b/src/ViewStyle.cxx
@@ -37,7 +37,6 @@ MarginStyle::MarginStyle(int style_, int width_, int mask_) noexcept :
 FontRealised::FontRealised() noexcept = default;
 
 FontRealised::~FontRealised() {
-	font.Release();
 }
 
 void FontRealised::Realise(Surface &surface, int zoomLevel, int technology, const FontSpecification &fs) {
@@ -48,13 +47,13 @@ void FontRealised::Realise(Surface &surface, int zoomLevel, int technology, cons
 
 	const float deviceHeight = static_cast<float>(surface.DeviceHeightFont(sizeZoomed));
 	const FontParameters fp(fs.fontName, deviceHeight / SC_FONT_SIZE_MULTIPLIER, fs.weight, fs.italic, fs.extraFontFlag, technology, fs.characterSet);
-	font.Create(fp);
+	font = Font::Allocate(fp);
 
-	ascent = static_cast<unsigned int>(surface.Ascent(font));
-	descent = static_cast<unsigned int>(surface.Descent(font));
-	capitalHeight = surface.Ascent(font) - surface.InternalLeading(font);
-	aveCharWidth = surface.AverageCharWidth(font);
-	spaceWidth = surface.WidthText(font, " ");
+	ascent = static_cast<unsigned int>(surface.Ascent(font.get()));
+	descent = static_cast<unsigned int>(surface.Descent(font.get()));
+	capitalHeight = surface.Ascent(font.get()) - surface.InternalLeading(font.get());
+	aveCharWidth = surface.AverageCharWidth(font.get());
+	spaceWidth = surface.WidthText(font.get(), " ");
 }
 
 ViewStyle::ViewStyle() : markers(MARKER_MAX + 1), indicators(INDICATOR_MAX + 1) {
@@ -345,7 +344,7 @@ void ViewStyle::Refresh(Surface &surface, int tabInChars) {
 	controlCharWidth = 0.0;
 	if (controlCharSymbol >= 32) {
 		const char cc[2] = { static_cast<char>(controlCharSymbol), '\0' };
-		controlCharWidth = surface.WidthText(styles[STYLE_CONTROLCHAR].font, cc);
+		controlCharWidth = surface.WidthText(styles[STYLE_CONTROLCHAR].font.get(), cc);
 	}
 
 	CalculateMarginWidthAndMask();
diff --git a/src/ViewStyle.h b/src/ViewStyle.h
index dc47ed380..b07c34a08 100644
--- a/src/ViewStyle.h
+++ b/src/ViewStyle.h
@@ -29,7 +29,7 @@ public:
 
 class FontRealised : public FontMeasurements {
 public:
-	Font font;
+	std::shared_ptr<Font> font;
 	FontRealised() noexcept;
 	// FontRealised objects can not be copied.
 	FontRealised(const FontRealised &) = delete;