oak-editor/engine/timeline/timelineundosplit.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 "timelineundosplit.h"

#include "node/block/clip/clip.h"
#include "node/block/transition/transition.h"
#include "node/nodeundo.h"

namespace olive
{

//
// BlockSplitCommand
//
void BlockSplitCommand::prepare()
{
	reconnect_tree_command_ = new MultiUndoCommand();
	new_block_ = static_cast<Block *>(
		Node::copy_node_in_graph(block_, reconnect_tree_command_));
}

void BlockSplitCommand::redo()
{
	old_length_ = block_->length();

	Q_ASSERT(point_ > block_->in() && point_ < block_->out());

	reconnect_tree_command_->redo_now();

	// Determine our new lengths
	Rational new_length = point_ - block_->in();
	Rational new_part_length = block_->out() - point_;

	// Begin an operation
	Track *track = block_->track();

	// Set lengths
	block_->set_length_and_media_out(new_length);
	new_block()->set_length_and_media_in(new_part_length);

	// Insert new block
	track->insert_block_after(new_block(), block_);

	if (ClipBlock *new_clip = dynamic_cast<ClipBlock *>(new_block_)) {
		ClipBlock *old_clip = static_cast<ClipBlock *>(block_);
		new_clip->add_cache_passthrough_from(old_clip);
	}

	// If the block had an out transition, we move it to the new block
	moved_transition_ = NodeInput();

	TransitionBlock *potential_transition =
		dynamic_cast<TransitionBlock *>(new_block()->next());
	if (potential_transition) {
		for (const Node::OutputConnection &output :
			 block_->output_connections()) {
			if (output.second.node() == potential_transition) {
				moved_transition_ = NodeInput(potential_transition,
											  TransitionBlock::k_out_block_input);
				Node::disconnect_edge(block_, moved_transition_);
				Node::connect_edge(new_block(), moved_transition_);
				break;
			}
		}
	}
}

void BlockSplitCommand::undo()
{
	Track *track = block_->track();

	if (moved_transition_.is_valid()) {
		Node::disconnect_edge(new_block(), moved_transition_);
		Node::connect_edge(block_, moved_transition_);
	}

	block_->set_length_and_media_out(old_length_);
	track->ripple_remove_block(new_block());

	// If we ran a reconnect command, disconnect now
	reconnect_tree_command_->undo_now();
}

//
// BlockSplitPreservingLinksCommand
//
Block *BlockSplitPreservingLinksCommand::get_split(Block *original,
												  int time_index) const
{
	if (time_index >= 0 && time_index < times_.size()) {
		int original_index = blocks_.indexOf(original);
		if (original_index != -1) {
			return splits_.at(time_index).at(original_index);
		}
	}

	return nullptr;
}

void BlockSplitPreservingLinksCommand::prepare()
{
	splits_.resize(times_.size());

	for (int i = 0; i < times_.size(); i++) {
		const Rational &time = times_.at(i);

		// FIXME: I realize this isn't going to work if the times aren't ordered. I'm lazy so rather
		//        than writing in a sorting algorithm here, I'll just put an assert as a reminder
		//        if this ever becomes an issue.
		Q_ASSERT(i == 0 || time > times_.at(i - 1));

		QVector<Block *> splits(blocks_.size());

		for (int j = 0; j < blocks_.size(); j++) {
			Block *b = blocks_.at(j);

			if (b->in() < time && b->out() > time) {
				BlockSplitCommand *split_command =
					new BlockSplitCommand(b, time);
				split_command->redo_now();
				splits.replace(j, split_command->new_block());
				commands_.append(split_command);
			} else {
				splits.replace(j, nullptr);
			}
		}

		splits_.replace(i, splits);
	}

	// Now that we've determined all the splits, we can relink everything
	for (int i = 0; i < blocks_.size(); i++) {
		Block *a = blocks_.at(i);

		for (int j = 0; j < blocks_.size(); j++) {
			if (i == j) {
				continue;
			}

			Block *b = blocks_.at(j);

			if (Block::are_linked(a, b)) {
				// These blocks are linked, ensure all the splits are linked too

				foreach (const QVector<Block *> &split_list, splits_) {
					NodeLinkCommand *blc = new NodeLinkCommand(
						split_list.at(i), split_list.at(j), true);
					blc->redo_now();
					commands_.append(blc);
				}
			}
		}
	}
}

//
// TrackSplitAtTimeCommand
//
void TrackSplitAtTimeCommand::prepare()
{
	// Find Block that contains this time
	Block *b = track_->block_containing_time(point_);

	if (b) {
		command_ = new BlockSplitCommand(b, point_);
	}
}

}