oak-editor/app/widget/handmovableview/handmovableview.cpp

/***

  Olive - Non-Linear Video Editor
  Copyright (C) 2022 Olive Team
  Modifications Copyright (C) 2025 mikesolar

  This program 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.

  This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.

***/

#include "handmovableview.h"

#include <QMouseEvent>

#include "config/config.h"
#include "core.h"

namespace olive
{

#define super QGraphicsView

HandMovableView::HandMovableView(QWidget *parent)
	: super(parent)
	, dragging_hand_(false)
	, default_drag_mode_(NoDrag)
	, is_timeline_axes_(false)
{
	connect(Core::instance(), &Core::tool_changed, this,
			&HandMovableView::application_tool_changed);
}

void HandMovableView::application_tool_changed(Tool::Item tool)
{
	if (tool == Tool::k_hand) {
		setDragMode(ScrollHandDrag);
		setInteractive(false);
	} else {
		setDragMode(default_drag_mode_);
		setInteractive(true);
	}

	ToolChangedEvent(tool);
}

bool HandMovableView::hand_press(QMouseEvent *event)
{
	if (event->button() == Qt::MiddleButton) {
		pre_hand_drag_mode_ = dragMode();
		dragging_hand_ = true;

		setDragMode(ScrollHandDrag);
		setInteractive(false);

		// Transform mouse event to act like the left button is pressed
		QMouseEvent transformed(event->type(), event->pos(), Qt::LeftButton,
								Qt::LeftButton, event->modifiers());

		transformed_pos_ = QPoint(0, 0);

		super::mousePressEvent(&transformed);

		return true;
	}

	return false;
}

bool HandMovableView::hand_move(QMouseEvent *event)
{
	if (dragging_hand_) {
		// Transform mouse event to act like the left button is pressed
		QPoint adjustment(0, 0);

		QMouseEvent transformed(event->type(), event->pos() - transformed_pos_,
								Qt::LeftButton, Qt::LeftButton,
								event->modifiers());

		if (event->pos().x() < 0) {
			transformed_pos_.setX(transformed_pos_.x() + width());
			adjustment.setX(width());
		} else if (event->pos().x() >= width()) {
			transformed_pos_.setX(transformed_pos_.x() - width());
			adjustment.setX(-width());
		}

		if (event->pos().y() < 0) {
			transformed_pos_.setY(transformed_pos_.y() + height());
			adjustment.setY(height());
		} else if (event->pos().y() >= height()) {
			transformed_pos_.setY(transformed_pos_.y() - height());
			adjustment.setY(-height());
		}

		if (!adjustment.isNull()) {
			QCursor::setPos(QCursor::pos() + adjustment);
		}

		super::mouseMoveEvent(&transformed);
	}
	return dragging_hand_;
}

bool HandMovableView::hand_release(QMouseEvent *event)
{
	if (dragging_hand_) {
		// Transform mouse event to act like the left button is pressed
		QMouseEvent transformed(event->type(), event->localPos(),
								event->windowPos(), event->screenPos(),
								Qt::LeftButton, Qt::LeftButton,
								event->modifiers(), event->source());

		super::mouseReleaseEvent(&transformed);

		setInteractive(true);
		setDragMode(pre_hand_drag_mode_);

		dragging_hand_ = false;

		return true;
	}

	return false;
}

void HandMovableView::set_default_drag_mode(HandMovableView::DragMode mode)
{
	default_drag_mode_ = mode;
	setDragMode(default_drag_mode_);
}

const HandMovableView::DragMode &HandMovableView::get_default_drag_mode() const
{
	return default_drag_mode_;
}

bool HandMovableView::WheelEventIsAZoomEvent(QWheelEvent *event)
{
	return (static_cast<bool>(event->modifiers() & Qt::ControlModifier) ==
			!OAK_CONFIG("ScrollZooms").toBool());
}

qreal HandMovableView::get_scroll_zoom_multiplier(QWheelEvent *event)
{
	qreal v =
		(static_cast<qreal>(event->angleDelta().x() + event->angleDelta().y()) *
		 0.001);
	if (event->inverted()) {
		v = -v;
	}
	return 1.0 + v;
}

void HandMovableView::wheelEvent(QWheelEvent *event)
{
	if (WheelEventIsAZoomEvent(event)) {
		if (!event->angleDelta().isNull()) {
			qreal multiplier = get_scroll_zoom_multiplier(event);

			QPointF cursor_pos;
#if QT_VERSION >= QT_VERSION_CHECK(5, 14, 0)
			cursor_pos = event->position();
#else
			cursor_pos = event->posF();
#endif

			zoom_into_cursor_position(event, multiplier, cursor_pos);
		}
	} else if (is_timeline_axes_) {
#if (QT_VERSION >= QT_VERSION_CHECK(5, 12, 0))

		QPoint angle_delta = event->angleDelta();

		if (OAK_CONFIG("InvertTimelineScrollAxes")
				.toBool() // Check if config is set to invert timeline axes
			&&
			event->source() !=
				Qt::MouseEventSynthesizedBySystem) { // Never flip axes on Apple trackpads though
			angle_delta = QPoint(angle_delta.y(), angle_delta.x());
		}

		QWheelEvent e(
#if (QT_VERSION >= QT_VERSION_CHECK(5, 14, 0))
			event->position(), event->globalPosition(),
#else
			event->pos(), event->globalPos(),
#endif
			event->pixelDelta(), angle_delta, event->buttons(),
			event->modifiers(), event->phase(), event->inverted(),
			event->source());

#else

		Qt::Orientation orientation = event->orientation();

		if (OAK_CONFIG("InvertTimelineScrollAxes").toBool()) {
			orientation = (orientation == Qt::Horizontal) ? Qt::Vertical :
															Qt::Horizontal;
		}

		QWheelEvent e(event->pos(), event->globalPos(), event->pixelDelta(),
					  event->angleDelta(), event->delta(), orientation,
					  event->buttons(), event->modifiers());
#endif

		super::wheelEvent(&e);
	} else {
		super::wheelEvent(event);
	}
}

void HandMovableView::zoom_into_cursor_position(QWheelEvent *event,
											 double multiplier,
											 const QPointF &cursor_pos)
{
	Q_UNUSED(event)
	Q_UNUSED(multiplier)
	Q_UNUSED(cursor_pos)
}

}