From 8b8a02b4bd250d28bc0f42287ca3d167b7210f39 Mon Sep 17 00:00:00 2001
From: Neil <nyamatongwe@gmail.com>
Date: Fri, 19 Mar 2021 16:15:16 +1100
Subject: UTF-8 text drawing and measurement. Move SurfaceGDI::WidthText to
 match declaration order.

---
 qt/ScintillaEditBase/PlatQt.cpp | 81 +++++++++++++++++++++++++++++++++++++++++
 qt/ScintillaEditBase/PlatQt.h   | 11 ++++++
 2 files changed, 92 insertions(+)

(limited to 'qt/ScintillaEditBase')

diff --git a/qt/ScintillaEditBase/PlatQt.cpp b/qt/ScintillaEditBase/PlatQt.cpp
index 6a26d47c4..a1adf0a0d 100644
--- a/qt/ScintillaEditBase/PlatQt.cpp
+++ b/qt/ScintillaEditBase/PlatQt.cpp
@@ -557,6 +557,87 @@ XYPOSITION SurfaceImpl::WidthText(const Font *font, std::string_view text)
 	return metrics.width(su);
 }
 
+void SurfaceImpl::DrawTextNoClipUTF8(PRectangle rc,
+				 const Font *font,
+				 XYPOSITION ybase,
+				 std::string_view text,
+				 ColourDesired fore,
+				 ColourDesired back)
+{
+	SetFont(font);
+	PenColour(fore);
+
+	GetPainter()->setBackground(QColorFromCA(back));
+	GetPainter()->setBackgroundMode(Qt::OpaqueMode);
+	QString su = QString::fromUtf8(text.data(), static_cast<int>(text.length()));
+	GetPainter()->drawText(QPointF(rc.left, ybase), su);
+}
+
+void SurfaceImpl::DrawTextClippedUTF8(PRectangle rc,
+				  const Font *font,
+				  XYPOSITION ybase,
+				  std::string_view text,
+				  ColourDesired fore,
+				  ColourDesired back)
+{
+	SetClip(rc);
+	DrawTextNoClip(rc, font, ybase, text, fore, back);
+	PopClip();
+}
+
+void SurfaceImpl::DrawTextTransparentUTF8(PRectangle rc,
+				      const Font *font,
+				      XYPOSITION ybase,
+				      std::string_view text,
+	ColourDesired fore)
+{
+	SetFont(font);
+	PenColour(fore);
+
+	GetPainter()->setBackgroundMode(Qt::TransparentMode);
+	QString su = QString::fromUtf8(text.data(), static_cast<int>(text.length()));
+	GetPainter()->drawText(QPointF(rc.left, ybase), su);
+}
+
+void SurfaceImpl::MeasureWidthsUTF8(const Font *font,
+				std::string_view text,
+				XYPOSITION *positions)
+{
+	if (!font)
+		return;
+	QString su = QString::fromUtf8(text.data(), static_cast<int>(text.length()));
+	QTextLayout tlay(su, *FontPointer(font), GetPaintDevice());
+	tlay.beginLayout();
+	QTextLine tl = tlay.createLine();
+	tlay.endLayout();
+	int fit = su.size();
+	int ui=0;
+	size_t i=0;
+	while (ui<fit) {
+		const unsigned char uch = text[i];
+		const unsigned int byteCount = UTF8BytesOfLead[uch];
+		const int codeUnits = UTF16LengthFromUTF8ByteCount(byteCount);
+		qreal xPosition = tl.cursorToX(ui+codeUnits);
+		for (size_t bytePos=0; (bytePos<byteCount) && (i<text.length()); bytePos++) {
+			positions[i++] = xPosition;
+		}
+		ui += codeUnits;
+	}
+	XYPOSITION lastPos = 0;
+	if (i > 0)
+		lastPos = positions[i-1];
+	while (i<text.length()) {
+		positions[i++] = lastPos;
+	}
+}
+
+XYPOSITION SurfaceImpl::WidthTextUTF8(const Font *font, std::string_view text)
+{
+	QFontMetricsF metrics(*FontPointer(font), device);
+	QString su = QString::fromUtf8(text.data(), static_cast<int>(text.length()));
+	return metrics.width(su);
+}
+
 XYPOSITION SurfaceImpl::Ascent(const Font *font)
 {
 	QFontMetricsF metrics(*FontPointer(font), device);
diff --git a/qt/ScintillaEditBase/PlatQt.h b/qt/ScintillaEditBase/PlatQt.h
index c690e7697..a743a4be5 100644
--- a/qt/ScintillaEditBase/PlatQt.h
+++ b/qt/ScintillaEditBase/PlatQt.h
@@ -126,6 +126,17 @@ public:
 	void MeasureWidths(const Font *font, std::string_view text,
 		XYPOSITION *positions) override;
 	XYPOSITION WidthText(const Font *font, std::string_view text) override;
+
+	void DrawTextNoClipUTF8(PRectangle rc, const Font *font_, XYPOSITION ybase,
+		std::string_view text, ColourDesired fore, ColourDesired back) override;
+	void DrawTextClippedUTF8(PRectangle rc, const Font *font_, XYPOSITION ybase,
+		std::string_view text, ColourDesired fore, ColourDesired back) override;
+	void DrawTextTransparentUTF8(PRectangle rc, const Font *font_, XYPOSITION ybase,
+		std::string_view text, ColourDesired fore) override;
+	void MeasureWidthsUTF8(const Font *font_, std::string_view text,
+		XYPOSITION *positions) override;
+	XYPOSITION WidthTextUTF8(const Font *font_, std::string_view text) override;
+
 	XYPOSITION Ascent(const Font *font) override;
 	XYPOSITION Descent(const Font *font) override;
 	XYPOSITION InternalLeading(const Font *font) override;
-- 
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