Add Ui::SlideAnimation.

gyp/sources.txt

@@ -14,6 +14,8 @@
 <(src_loc)/ui/effects/radial_animation.h
 <(src_loc)/ui/effects/ripple_animation.cpp
 <(src_loc)/ui/effects/ripple_animation.h
+<(src_loc)/ui/effects/slide_animation.cpp
+<(src_loc)/ui/effects/slide_animation.h
 <(src_loc)/ui/image/image_prepare.cpp
 <(src_loc)/ui/image/image_prepare.h
 <(src_loc)/ui/layers/box_content.cpp

ui/effects/slide_animation.cpp

@@ -0,0 +1,80 @@
+// 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/effects/slide_animation.h"
+
+#include <QtGui/QPainter>
+
+namespace Ui {
+
+void SlideAnimation::setSnapshots(
+		QPixmap leftSnapshot,
+		QPixmap rightSnapshot) {
+	Expects(!leftSnapshot.isNull());
+	Expects(!rightSnapshot.isNull());
+
+	_leftSnapshot = std::move(leftSnapshot);
+	_rightSnapshot = std::move(rightSnapshot);
+	_leftSnapshot.setDevicePixelRatio(style::DevicePixelRatio());
+	_rightSnapshot.setDevicePixelRatio(style::DevicePixelRatio());
+}
+
+void SlideAnimation::paintFrame(QPainter &p, int x, int y, int outerWidth) {
+	const auto dt = _animation.value(1.);
+	if (!animating()) {
+		return;
+	}
+
+	const auto pixelRatio = style::DevicePixelRatio();
+	const auto easeOut = anim::easeOutCirc(1., dt);
+	const auto easeIn = anim::easeInCirc(1., dt);
+	const auto arrivingAlpha = easeIn;
+	const auto departingAlpha = 1. - easeOut;
+	const auto leftCoord = _slideLeft
+		? anim::interpolate(-_leftSnapshotWidth, 0, easeOut)
+		: anim::interpolate(0, -_leftSnapshotWidth, easeIn);
+	const auto leftAlpha = (_slideLeft ? arrivingAlpha : departingAlpha);
+	const auto rightCoord = _slideLeft
+		? anim::interpolate(0, _rightSnapshotWidth, easeIn)
+		: anim::interpolate(_rightSnapshotWidth, 0, easeOut);
+	const auto rightAlpha = (_slideLeft ? departingAlpha : arrivingAlpha);
+
+	if (_overflowHidden) {
+		const auto leftWidth = (_leftSnapshotWidth + leftCoord);
+		if (leftWidth > 0) {
+			p.setOpacity(leftAlpha);
+			p.drawPixmap(
+				x,
+				y,
+				leftWidth,
+				_leftSnapshotHeight,
+				_leftSnapshot,
+				(_leftSnapshot.width() - leftWidth * pixelRatio),
+				0,
+				leftWidth * pixelRatio,
+				_leftSnapshot.height());
+		}
+		const auto rightWidth = _rightSnapshotWidth - rightCoord;
+		if (rightWidth > 0) {
+			p.setOpacity(rightAlpha);
+			p.drawPixmap(
+				x + rightCoord,
+				y,
+				_rightSnapshot,
+				0,
+				0,
+				rightWidth * pixelRatio,
+				_rightSnapshot.height());
+		}
+	} else {
+		p.setOpacity(leftAlpha);
+		p.drawPixmap(x + leftCoord, y, _leftSnapshot);
+		p.setOpacity(rightAlpha);
+		p.drawPixmap(x + rightCoord, y, _rightSnapshot);
+	}
+}
+
+} // namespace Ui

ui/effects/slide_animation.h

@@ -0,0 +1,58 @@
+// 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 "ui/effects/animations.h"
+
+namespace Ui {
+
+class SlideAnimation {
+public:
+	void setSnapshots(QPixmap leftSnapshot, QPixmap rightSnapshot);
+
+	void setOverflowHidden(bool hidden) {
+		_overflowHidden = hidden;
+	}
+
+	template <typename Lambda>
+	void start(bool slideLeft, Lambda &&updateCallback, float64 duration);
+
+	void paintFrame(QPainter &p, int x, int y, int outerWidth);
+
+	bool animating() const {
+		return _animation.animating();
+	}
+
+private:
+	Ui::Animations::Simple _animation;
+	QPixmap _leftSnapshot;
+	QPixmap _rightSnapshot;
+	bool _slideLeft = false;
+	bool _overflowHidden = true;
+	int _leftSnapshotWidth = 0;
+	int _leftSnapshotHeight = 0;
+	int _rightSnapshotWidth = 0;
+
+};
+
+template <typename Lambda>
+void SlideAnimation::start(
+		bool slideLeft,
+		Lambda &&updateCallback,
+		float64 duration) {
+	_slideLeft = slideLeft;
+	if (_slideLeft) {
+		std::swap(_leftSnapshot, _rightSnapshot);
+	}
+	const auto pixelRatio = style::DevicePixelRatio();
+	_leftSnapshotWidth = _leftSnapshot.width() / pixelRatio;
+	_leftSnapshotHeight = _leftSnapshot.height() / pixelRatio;
+	_rightSnapshotWidth = _rightSnapshot.width() / pixelRatio;
+	_animation.start(std::forward<Lambda>(updateCallback), 0., 1., duration);
+}
+
+} // namespace Ui