drawing reworked into c++ plugin, moved input handler to Interactions.qml as a PointHandler

Plugins/ZShell/Internal/strokecanvasrenderer.cpp

@@ -0,0 +1,61 @@
+#include "strokecanvasrenderer.hpp"
+#include "strokecanvasitem.hpp"
+
+namespace ZShell::internal {
+
+static void drawStroke(
+	QCanvasPainter *painter,
+	const QVector<QPointF> &points,
+	const QColor &color,
+	float width) {
+
+	if (points.isEmpty())
+		return;
+
+	painter->setStrokeStyle(color);
+	painter->setFillStyle(color);
+	painter->setLineWidth(width);
+	painter->setLineCap(QCanvasPainter::LineCap::Round);
+	painter->setLineJoin(QCanvasPainter::LineJoin::Round);
+
+	if (points.size() == 1) {
+		painter->beginPath();
+		painter->circle(points.front(), width * 0.5f);
+		painter->fill();
+		return;
+	}
+
+	painter->beginPath();
+	painter->moveTo(points[0]);
+
+	for (qsizetype i = 1; i < points.size(); ++i)
+		painter->lineTo(points[i]);
+
+	painter->stroke();
+}
+
+void StrokeCanvasRenderer::synchronizeData(QCanvasPainterItem *item) {
+	auto *canvas = static_cast<StrokeCanvasItem *>(item);
+
+	m_penColor = canvas->m_penColor;
+	m_penWidth = canvas->m_penWidth;
+
+	m_strokes = canvas->m_strokes;
+	m_currentStroke = canvas->m_currentStroke;
+}
+
+void StrokeCanvasRenderer::paint(QCanvasPainter *painter) {
+	painter->clearRect(0, 0, width(), height());
+
+	for (const auto &stroke : m_strokes)
+		drawStroke(painter, stroke.points, stroke.color, stroke.width);
+
+	drawStroke(
+		painter,
+		m_currentStroke.points,
+		m_currentStroke.color,
+		m_currentStroke.width
+		);
+}
+
+};