oak-editor/app/widget/timelinewidget/trackview/trackviewsplitter.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 "trackviewsplitter.h"

#include <QDebug>
#include <QPainter>

#include "node/output/track/track.h"

namespace olive
{

TrackViewSplitter::TrackViewSplitter(Qt::Alignment vertical_alignment,
									 QWidget *parent)
	: QSplitter(Qt::Vertical, parent)
	, alignment_(vertical_alignment)
	, spacer_height_(0)
{
	setHandleWidth(1);

	int initial_height = 0;

	// Add empty spacer so we get a splitter handle after the last element
	QWidget *spacer = new QWidget();
	addWidget(spacer);

	setFixedHeight(initial_height);
}

void TrackViewSplitter::handle_receiver(TrackViewSplitterHandle *h, int diff)
{
	int ele_id = -1;

	for (int i = 0; i < count(); i++) {
		if (handle(i) == h) {
			ele_id = i;
			break;
		}
	}

	// The handle index is actually always one above the element index
	if (alignment_ == Qt::AlignTop) {
		ele_id--;
	} else if (alignment_ == Qt::AlignBottom) {
		diff = -diff;
	}

	QList<int> element_sizes = sizes();

	int old_ele_sz = element_sizes.at(ele_id);

	// Transform element size by diff
	int new_ele_sz = old_ele_sz + diff;

	// Limit by track minimum height
	new_ele_sz = qMax(new_ele_sz, Track::get_minimum_track_height_in_pixels());

	if (alignment_ == Qt::AlignBottom) {
		ele_id = count() - ele_id - 1;
	}

	set_track_height(ele_id, new_ele_sz);

	emit track_height_changed(ele_id, new_ele_sz);
}

void TrackViewSplitter::set_track_height(int index, int h)
{
	QList<int> element_sizes = sizes();

	if (alignment_ == Qt::AlignBottom) {
		index = count() - index - 1;
	}

	int old_ele_sz = element_sizes.at(index);

	int diff = h - old_ele_sz;

	// Set new size on element
	element_sizes.replace(index, h);
	setSizes(element_sizes);

	// Increase height by the difference
	setFixedHeight(height() + diff);
}

void TrackViewSplitter::set_height_with_sizes(QList<int> sizes)
{
	int start_height = 0;

	// Add spacer height too
	if (alignment_ == Qt::AlignBottom) {
		sizes.replace(0, spacer_height_);
	} else {
		sizes.replace(sizes.size() - 1, spacer_height_);
	}

	foreach (int s, sizes) {
		start_height += s + handleWidth();
	}

	// The spacer doesn't need a handle width
	start_height -= handleWidth();

	setFixedHeight(start_height);
	setSizes(sizes);
}

void TrackViewSplitter::insert(int index, int height, QWidget *item)
{
	QList<int> sz = sizes();

	if (alignment_ == Qt::AlignBottom) {
		index = count() - index;
	}

	sz.insert(index, height);
	insertWidget(index, item);

	set_height_with_sizes(sz);
}

void TrackViewSplitter::remove(int index)
{
	QList<int> sz = sizes();

	if (alignment_ == Qt::AlignBottom) {
		index = count() - 1 - index;
	}

	sz.removeAt(index);
	delete widget(index);

	set_height_with_sizes(sz);
}

void TrackViewSplitter::set_spacer_height(int height)
{
	spacer_height_ = height;
	set_height_with_sizes(sizes());
}

QSplitterHandle *TrackViewSplitter::createHandle()
{
	return new TrackViewSplitterHandle(orientation(), this);
}

TrackViewSplitterHandle::TrackViewSplitterHandle(Qt::Orientation orientation,
												 QSplitter *parent)
	: QSplitterHandle(orientation, parent)
	, dragging_(false)
{
}

void TrackViewSplitterHandle::mousePressEvent(QMouseEvent *)
{
}

void TrackViewSplitterHandle::mouseMoveEvent(QMouseEvent *)
{
	if (dragging_) {
		static_cast<TrackViewSplitter *>(parent())->handle_receiver(
			this, QCursor::pos().y() - drag_y_);
	}

	drag_y_ = QCursor::pos().y();
	dragging_ = true;
}

void TrackViewSplitterHandle::mouseReleaseEvent(QMouseEvent *)
{
	dragging_ = false;
}

void TrackViewSplitterHandle::paintEvent(QPaintEvent *)
{
	QPainter p(this);
	p.fillRect(rect(), palette().base());
}

}