Files
flameshot/src/widgets/draggablewidgetmaker.cpp
2020-12-06 08:33:19 +02:00

82 lines
2.7 KiB
C++

// Copyright(c) 2017-2019 Alejandro Sirgo Rica & Contributors
//
// This file is part of Flameshot.
//
// Flameshot 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.
//
// Flameshot 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.
//
// You should have received a copy of the GNU General Public License
// along with Flameshot. If not, see <http://www.gnu.org/licenses/>.
#include "draggablewidgetmaker.h"
#include <QMouseEvent>
DraggableWidgetMaker::DraggableWidgetMaker(QObject* parent)
: QObject(parent)
{}
void DraggableWidgetMaker::makeDraggable(QWidget* widget)
{
widget->installEventFilter(this);
}
bool DraggableWidgetMaker::eventFilter(QObject* obj, QEvent* event)
{
auto widget = static_cast<QWidget*>(obj);
// based on https://stackoverflow.com/a/12221360/964478
switch (event->type()) {
case QEvent::MouseButtonPress: {
auto mouseEvent = static_cast<QMouseEvent*>(event);
m_isPressing = false;
m_isDragging = false;
if (mouseEvent->button() == Qt::LeftButton) {
m_isPressing = true;
m_mousePressPos = mouseEvent->globalPos();
m_mouseMovePos = m_mousePressPos;
}
} break;
case QEvent::MouseMove: {
auto mouseEvent = static_cast<QMouseEvent*>(event);
if (m_isPressing) {
QPoint widgetPos = widget->mapToGlobal(widget->pos());
QPoint eventPos = mouseEvent->globalPos();
QPoint diff = eventPos - m_mouseMovePos;
QPoint newPos = widgetPos + diff;
widget->move(widget->mapFromGlobal(newPos));
if (!m_isDragging) {
QPoint totalMovedDiff = eventPos - m_mousePressPos;
if (totalMovedDiff.manhattanLength() > 3) {
m_isDragging = true;
}
}
m_mouseMovePos = eventPos;
}
} break;
case QEvent::MouseButtonRelease: {
if (m_isDragging) {
m_isPressing = false;
m_isDragging = false;
event->ignore();
return true;
}
} break;
default:
break;
}
return QObject::eventFilter(obj, event);
}