Place symbol texts: the icon shows where the texts go

Each of the nine points has its own icon: a grey square for the symbol
and two bars for the lines of text, where they will go and lined up as
they will be. The grid shows them instead of arrows, and the toolbar
button takes the icon of the point chosen last, so that one sees where
a click on it puts the texts.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

sources/symboltextplacement.cpp

@@ -22,7 +22,11 @@
 #include "qetgraphicsitem/element.h"
 #include "qetgraphicsitem/elementtextitemgroup.h"
 
+#include <QApplication>
 #include <QCoreApplication>
+#include <QPainter>
+#include <QPalette>
+#include <QPixmap>
 #include <QUndoCommand>
 
 namespace {
@@ -127,3 +131,40 @@ QUndoCommand *SymbolTextPlacement::place(const QList<Element *> &elements, Qt::A
 	}
 	return undo;
 }
+
+QIcon SymbolTextPlacement::icon(Qt::Alignment where)
+{
+	const Qt::Alignment lines = linesFor(where);
+	const QPalette palette = QApplication::palette();
+	QIcon icon;
+	for (int size : {16, 22, 24, 32, 48})
+	{
+		QPixmap pixmap(size, size);
+		pixmap.fill(Qt::transparent);
+		QPainter painter(&pixmap);
+		painter.setRenderHint(QPainter::Antialiasing);
+		painter.scale(size / 24.0, size / 24.0);
+
+			//The symbol
+		painter.setPen(Qt::NoPen);
+		painter.setBrush(palette.color(QPalette::Mid));
+		painter.drawRect(QRectF(7, 7, 10, 10));
+
+			//Two lines of text, a long one over a short one
+		const qreal right = (where & Qt::AlignLeft) ? 5.5 : (where & Qt::AlignRight) ? 24 : 18.5;
+		const qreal left = (where & Qt::AlignLeft) ? 0 : (where & Qt::AlignRight) ? 18.5 : 5.5;
+		const qreal top = (where & Qt::AlignTop) ? 0 : (where & Qt::AlignBottom) ? 18.5 : 9.25;
+		painter.setBrush(palette.color(QPalette::WindowText));
+		for (int i = 0; i < 2; ++i)
+		{
+			const qreal width = i == 0 ? right - left : (right - left) * 0.6;
+			const qreal x = lines == Qt::AlignRight ? right - width
+						  : lines == Qt::AlignLeft  ? left
+						  : (left + right - width) / 2;
+			painter.drawRect(QRectF(x, top + i * 3, width, 2.5));
+		}
+		painter.end();
+		icon.addPixmap(pixmap);
+	}
+	return icon;
+}