From 5bcd894429e7a85164458261965a4c9e3c1f2d2e Mon Sep 17 00:00:00 2001
From: 23rd <23rd@vivaldi.net>
Date: Sun, 17 Jan 2021 04:56:47 +0300
Subject: [PATCH] Added initial implementation of arc painter.

---
 CMakeLists.txt           |  2 +
 ui/paint/arcs.cpp        | 92 ++++++++++++++++++++++++++++++++++++++++
 ui/paint/arcs.h          | 68 +++++++++++++++++++++++++++++
 ui/widgets/widgets.style | 11 +++++
 4 files changed, 173 insertions(+)
 create mode 100644 ui/paint/arcs.cpp
 create mode 100644 ui/paint/arcs.h

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 56b575a..770ba1a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -69,6 +69,8 @@ PRIVATE
     ui/layers/layer_manager.h
     ui/layers/layer_widget.cpp
     ui/layers/layer_widget.h
+    ui/paint/arcs.cpp
+    ui/paint/arcs.h
     ui/paint/blob.cpp
     ui/paint/blob.h
     ui/paint/blobs.cpp
diff --git a/ui/paint/arcs.cpp b/ui/paint/arcs.cpp
new file mode 100644
index 0000000..9538b99
--- /dev/null
+++ b/ui/paint/arcs.cpp
@@ -0,0 +1,92 @@
+// This file is part of Desktop App Toolkit,
+// a set of libraries for developing nice desktop applications.
+//
+// For license and copyright information please follow this link:
+// https://github.com/desktop-app/legal/blob/master/LEGAL
+//
+#include "ui/paint/arcs.h"
+
+#include "ui/painter.h"
+
+namespace Ui::Paint {
+
+ArcsAnimation::ArcsAnimation(
+	const style::ArcsAnimation &st,
+	int count,
+	VerticalDirection direction,
+	int centerX,
+	int startY)
+: _st(st)
+, _center(centerX)
+, _start(startY)
+, _horizontalDirection(HorizontalDirection::None)
+, _verticalDirection(direction)
+, _startAngle((st.deltaAngle
+	+ ((direction == VerticalDirection::Up) ? 90 : 270)) * 16)
+, _spanAngle(-st.deltaAngle * 2 * 16) {
+	initArcs(count);
+}
+
+ArcsAnimation::ArcsAnimation(
+	const style::ArcsAnimation &st,
+	int count,
+	HorizontalDirection direction,
+	int startX,
+	int centerY)
+: _st(st)
+, _center(centerY)
+, _start(startX)
+, _horizontalDirection(direction)
+, _verticalDirection(VerticalDirection::None)
+, _startAngle((st.deltaAngle
+	+ ((direction == HorizontalDirection::Left) ? 180 : 0)) * 16)
+, _spanAngle(-st.deltaAngle * 2 * 16) {
+	initArcs(count);
+}
+
+void ArcsAnimation::initArcs(int count) {
+	_arcs.reserve(count);
+
+	for (auto i = 0; i < count; i++) {
+		auto arc = Arc{ .rect = computeArcRect(i) };
+		_arcs.push_back(std::move(arc));
+	}
+}
+
+QRectF ArcsAnimation::computeArcRect(int index) const {
+	const auto w = _st.startWidth + _st.deltaWidth * index;
+	const auto h = _st.startHeight + _st.deltaHeight * index;
+	if (_horizontalDirection != HorizontalDirection::None) {
+		auto rect = QRectF(0, _center - h / 2.0, w, h);
+		if (_horizontalDirection == HorizontalDirection::Right) {
+			rect.moveRight(_start + index * _st.space);
+		} else {
+			rect.moveLeft(_start - index * _st.space);
+		}
+		return rect;
+	} else if (_verticalDirection != VerticalDirection::None) {
+		auto rect = QRectF(_center - w / 2.0, 0, w, h);
+		if (_verticalDirection == VerticalDirection::Up) {
+			rect.moveTop(_start - index * _st.space);
+		} else {
+			rect.moveBottom(_start + index * _st.space);
+		}
+		return rect;
+	}
+	return QRectF();
+}
+
+void ArcsAnimation::paint(Painter &p, std::optional<QColor> colorOverride) {
+	PainterHighQualityEnabler hq(p);
+	QPen pen;
+	pen.setWidth(_st.stroke);
+	pen.setCapStyle(Qt::RoundCap);
+	pen.setColor(colorOverride ? (*colorOverride) : _st.fg->c);
+	p.setPen(pen);
+	for (const auto &arc : _arcs) {
+		p.drawArc(arc.rect, _startAngle, _spanAngle);
+	}
+}
+
+
+} // namespace Ui::Paint
diff --git a/ui/paint/arcs.h b/ui/paint/arcs.h
new file mode 100644
index 0000000..1c4988e
--- /dev/null
+++ b/ui/paint/arcs.h
@@ -0,0 +1,68 @@
+// This file is part of Desktop App Toolkit,
+// a set of libraries for developing nice desktop applications.
+//
+// For license and copyright information please follow this link:
+// https://github.com/desktop-app/legal/blob/master/LEGAL
+//
+#pragma once
+
+#include "styles/style_widgets.h"
+
+class Painter;
+
+namespace Ui::Paint {
+
+class ArcsAnimation {
+public:
+
+	enum class HorizontalDirection {
+		Left,
+		Right,
+		None,
+	};
+
+	enum class VerticalDirection {
+		Up,
+		Down,
+		None,
+	};
+
+	ArcsAnimation(
+		const style::ArcsAnimation &st,
+		int count,
+		VerticalDirection direction,
+		int centerX,
+		int startY);
+
+	ArcsAnimation(
+		const style::ArcsAnimation &st,
+		int count,
+		HorizontalDirection direction,
+		int startX,
+		int centerY);
+
+	void paint(
+		Painter &p,
+		std::optional<QColor> colorOverride = std::nullopt);
+
+private:
+	struct Arc {
+		QRectF rect;
+	};
+
+	void initArcs(int count);
+	QRectF computeArcRect(int index) const;
+
+	const style::ArcsAnimation &_st;
+	const int _center;
+	const int _start;
+	const HorizontalDirection _horizontalDirection;
+	const VerticalDirection _verticalDirection;
+	const int _startAngle;
+	const int _spanAngle;
+
+	std::vector<Arc> _arcs;
+
+};
+
+} // namespace Ui::Paint
diff --git a/ui/widgets/widgets.style b/ui/widgets/widgets.style
index 11671a9..36f0e4d 100644
--- a/ui/widgets/widgets.style
+++ b/ui/widgets/widgets.style
@@ -410,6 +410,17 @@ CrossLineAnimation {
 	stroke: pixels;
 }
 
+ArcsAnimation {
+	fg: color;
+	stroke: pixels;
+	space: pixels;
+	deltaAngle: int;
+	deltaHeight: pixels;
+	deltaWidth: pixels;
+	startHeight: pixels;
+	startWidth: pixels;
+}
+
 MultiSelectItem {
 	padding: margins;
 	maxWidth: pixels;