Select › Color Range: sampled colours, Fuzziness, Invert, a live preview and the panel (13.3b)

src/UI/SampleButton.cpp

@@ -0,0 +1,48 @@
+#include "UI/SampleButton.h"
+#include "Rendering/EyedropperIcon.h"
+#include <QPainter>
+#include <QPainterPath>
+
+SampleButton::SampleButton(std::function<void(QPainter &, const QColor &)> glyph, QWidget *parent) : QToolButton(parent), m_glyph(std::move(glyph))
+{
+    setCheckable(true);
+    setFixedSize(24, 20);
+}
+
+void SampleButton::paintEvent(QPaintEvent *)
+{
+    QPainter painter(this);
+    painter.setRenderHint(QPainter::Antialiasing);
+    if (isChecked()) {
+        QColor tint = palette().color(QPalette::Highlight);
+        tint.setAlphaF(0.25f);
+        painter.setPen(Qt::NoPen);
+        painter.setBrush(tint);
+        painter.drawRoundedRect(QRectF(rect()), 4, 4);
+    }
+    m_glyph(painter, palette().color(QPalette::WindowText));
+}
+
+void sampleEyedropper(QPainter &painter, HueSampleMode mode, const QColor &ink)
+{
+    // A 14-point glyph, centred in the 24 by 20 frame.
+    painter.save();
+    painter.translate(5, 3);
+    painter.save();
+    painter.scale(14.0 / 18, 14.0 / 18);
+    painter.setPen(QPen(ink, 1.5, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
+    EyedropperIcon::paint(painter);
+    painter.restore();
+    if (mode != HueSampleMode::replace) {
+        // An 8-point disc, bottom right, nudged 3 and 1.
+        QPainterPath badge;
+        badge.addEllipse(QRectF(9, 7, 8, 8));
+        QPainterPath sign;
+        sign.setFillRule(Qt::WindingFill);
+        sign.addRect(QRectF(10.75, 10.4, 4.5, 1.2));
+        if (mode == HueSampleMode::add)
+            sign.addRect(QRectF(12.4, 8.75, 1.2, 4.5));
+        painter.fillPath(badge.subtracted(sign), ink);
+    }
+    painter.restore();
+}