initial commit for 0.4.18 version of Telegram Desktop

Telegram/SourceFiles/gui/scrollarea.h

@@ -0,0 +1,174 @@
+/*
+This file is part of Telegram Desktop,
+an unofficial desktop messaging app, see https://telegram.org
+
+Telegram Desktop is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+It is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+Full license: https://github.com/telegramdesktop/tdesktop/blob/master/LICENSE
+Copyright (c) 2014 John Preston, https://tdesktop.com
+*/
+#pragma once
+
+#include <QtWidgets/QScrollArea>
+#include "style.h"
+
+enum TouchScrollState {
+	TouchScrollManual, // Scrolling manually with the finger on the screen
+	TouchScrollAuto, // Scrolling automatically
+	TouchScrollAcceleration // Scrolling automatically but a finger is on the screen
+};
+
+class ScrollArea;
+
+class ScrollShadow : public QWidget {
+	Q_OBJECT
+
+public:
+
+	ScrollShadow(ScrollArea *parent, const style::flatScroll *st);
+
+	void paintEvent(QPaintEvent *e);
+
+public slots:
+
+	void changeVisibility(bool shown);
+
+private:
+
+	const style::flatScroll *_st;
+
+};
+
+class ScrollBar : public QWidget, public Animated {
+	Q_OBJECT
+
+public:
+
+	ScrollBar(ScrollArea *parent, bool vertical, const style::flatScroll *st);
+
+	void recountSize();
+
+	void paintEvent(QPaintEvent *e);
+	void enterEvent(QEvent *e);
+	void leaveEvent(QEvent *e);
+	void mouseMoveEvent(QMouseEvent *e);
+	void mousePressEvent(QMouseEvent *e);
+	void mouseReleaseEvent(QMouseEvent *e);
+	void resizeEvent(QResizeEvent *e);
+
+	bool animStep(float64 ms);
+
+	void hideTimeout(int64 dt);
+
+public slots:
+
+	void updateBar();
+	void onHideTimer();
+
+signals:
+
+	void topShadowVisibility(bool);
+	void bottomShadowVisibility(bool);
+
+private:
+
+	ScrollArea *_area;
+	const style::flatScroll *_st;
+
+	bool _vertical;
+	bool _over, _overbar, _moving;
+	bool _topSh, _bottomSh;
+
+	QPoint _dragStart;
+	QScrollBar *_connected;
+
+	int32 _startFrom, _scrollMax;
+
+	int64 _hideIn;
+	QTimer _hideTimer;
+
+	anim::cvalue a_bg, a_bar;
+	QRect _bar;
+};
+
+class ScrollArea : public QScrollArea {
+	Q_OBJECT
+
+public:
+
+	ScrollArea(QWidget *parent, const style::flatScroll &st = st::scrollDef, bool handleTouch = true);
+
+	bool viewportEvent(QEvent *e);
+	void touchEvent(QTouchEvent *e);
+
+	bool eventFilter(QObject *obj, QEvent *e);
+
+	void resizeEvent(QResizeEvent *e);
+	void moveEvent(QMoveEvent *e);
+
+	void enterEvent(QEvent *e);
+	void leaveEvent(QEvent *e);
+
+	int scrollWidth() const;
+	int scrollHeight() const;
+	int scrollLeftMax() const;
+	int scrollTopMax() const;
+	int scrollLeft() const;
+	int scrollTop() const;
+
+	void setWidget(QWidget *widget);
+
+	void rangeChanged(int oldMax, int newMax, bool vertical);
+
+public slots:
+
+	void scrollToY(int toTop, int toBottom = -1);
+	void onScrolled();
+
+	void onTouchTimer();
+	void onTouchScrollTimer();
+
+signals:
+
+	void scrolled();
+	void scrollStarted();
+	void scrollFinished();
+	void geometryChanged();
+
+private:
+
+	bool touchScroll(const QPoint &delta);
+
+	void touchScrollUpdated(const QPoint &screenPos);
+
+	void touchResetSpeed();
+	void touchUpdateSpeed();
+	void touchDeaccelerate(int32 elapsed);
+
+	style::flatScroll _st;
+	ScrollBar hor, vert;
+	ScrollShadow topSh, bottomSh;
+	int32 _horValue, _vertValue;
+
+	bool _touchEnabled;
+	QTimer _touchTimer;
+	bool _touchScroll, _touchPress, _touchRightButton;
+	QPoint _touchStart, _touchPrevPos, _touchPos;
+
+	TouchScrollState _touchScrollState;
+	bool _touchPrevPosValid, _touchWaitingAcceleration;
+	QPoint _touchSpeed;
+	uint64 _touchSpeedTime, _touchAccelerationTime, _touchTime;
+	QTimer _touchScrollTimer;
+
+	bool _widgetAcceptsTouch;
+
+};