sprotty/src/model-source/commit-model.ts

A next-gen framework for graphical views

/********************************************************************************
 * Copyright (c) 2019 TypeFox and others.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the Eclipse
 * Public License v. 2.0 are satisfied: GNU General Public License, version 2
 * with the GNU Classpath Exception which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 ********************************************************************************/

import { inject, injectable } from 'inversify';
import { Action } from 'sprotty-protocol/lib/actions';
import { SModelRoot } from 'sprotty-protocol/lib/model';
import { CommandExecutionContext, CommandReturn, SystemCommand } from '../base/commands/command';
import { SModelRootImpl } from '../base/model/smodel';
import { TYPES } from '../base/types';
import { ModelSource } from './model-source';

/**
 * Commit the current SModel back to the model source.
 *
 * The SModel (AKA internal model) contains a lot of dirty/transitional state, such
 * as intermediate move postions or handles. When a user interaction that spans multiple
 * commands finishes, it fires a CommitModelAction to write the final changes back to
 * the model source.
 */
export interface CommitModelAction extends Action {
    kind: typeof CommitModelAction.KIND;
}
export namespace CommitModelAction {
    export const KIND = 'commitModel';

    export function create(): CommitModelAction {
        return {
            kind: KIND
        };
    }
}

@injectable()
export class CommitModelCommand extends SystemCommand {
    static readonly KIND = CommitModelAction.KIND;

    @inject(TYPES.ModelSource) modelSource: ModelSource;

    originalModel: SModelRoot;
    newModel: SModelRoot;

    constructor(@inject(TYPES.Action) protected readonly action: CommitModelAction) {
        super();
    }

    execute(context: CommandExecutionContext): CommandReturn {
        this.newModel = context.modelFactory.createSchema(context.root);
        return this.doCommit(this.newModel, context.root, true);
    }

    protected doCommit(model: SModelRoot, result: SModelRootImpl, doSetOriginal: boolean): CommandReturn {
        const commitResult = this.modelSource.commitModel(model);
        if (commitResult instanceof Promise) {
            return commitResult.then(originalModel => {
                if (doSetOriginal)
                    this.originalModel = originalModel;
                return result;
            });
        } else {
            if (doSetOriginal)
                this.originalModel = commitResult;
            return result;
        }
    }

    undo(context: CommandExecutionContext): CommandReturn {
        return this.doCommit(this.originalModel, context.root, false);
    }

    redo(context: CommandExecutionContext): CommandReturn {
        return this.doCommit(this.newModel, context.root, false);
    }
}