org.rstudio.studio.client.workbench.views.source.model.DirtyState.java Source code

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Here is the source code for org.rstudio.studio.client.workbench.views.source.model.DirtyState.java

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/*
 * DirtyState.java
 *
 * Copyright (C) 2009-12 by RStudio, Inc.
 *
 * Unless you have received this program directly from RStudio pursuant
 * to the terms of a commercial license agreement with RStudio, then
 * this program is licensed to you under the terms of version 3 of the
 * GNU Affero General Public License. This program is distributed WITHOUT
 * ANY EXPRESS OR IMPLIED WARRANTY, INCLUDING THOSE OF NON-INFRINGEMENT,
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Please refer to the
 * AGPL (http://www.gnu.org/licenses/agpl-3.0.txt) for more details.
 *
 */
package org.rstudio.studio.client.workbench.views.source.model;

import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.event.logical.shared.HasValueChangeHandlers;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.event.shared.GwtEvent;
import com.google.gwt.event.shared.HandlerManager;
import com.google.gwt.event.shared.HandlerRegistration;
import org.rstudio.studio.client.common.ReadOnlyValue;
import org.rstudio.studio.client.workbench.views.source.editors.text.DocDisplay;
import org.rstudio.studio.client.workbench.views.source.editors.text.events.UndoRedoEvent;
import org.rstudio.studio.client.workbench.views.source.editors.text.events.UndoRedoHandler;

public class DirtyState implements ReadOnlyValue<Boolean> {
    public DirtyState(DocDisplay editor, boolean initialState) {
        editor_ = editor;

        if (initialState)
            markDirty(false);
        else
            markClean();

        editor_.addUndoRedoHandler(new UndoRedoHandler() {
            public void onUndoRedo(UndoRedoEvent event) {
                if (editor_.checkCleanStateToken(cleanUndoStateToken_))
                    markClean();
                else
                    markDirty(true);
            }
        });
    }

    public void markDirty(boolean allowUndoBackToClean) {
        if (!allowUndoBackToClean)
            cleanUndoStateToken_ = JavaScriptObject.createObject();

        if (!value_) {
            value_ = true;
            fire(value_);
        }
    }

    public void markClean() {
        cleanUndoStateToken_ = editor_.getCleanStateToken();
        if (value_) {
            value_ = false;
            fire(value_);
        }
    }

    public Boolean getValue() {
        return value_;
    }

    public HandlerRegistration addValueChangeHandler(ValueChangeHandler<Boolean> handler) {
        return handlers_.addHandler(ValueChangeEvent.getType(), handler);
    }

    public void fireEvent(GwtEvent<?> event) {
        handlers_.fireEvent(event);
    }

    private void fire(boolean value) {
        ValueChangeEvent.fire(new HasValueChangeHandlers<Boolean>() {
            public HandlerRegistration addValueChangeHandler(ValueChangeHandler<Boolean> handler) {
                throw new UnsupportedOperationException();
            }

            public void fireEvent(GwtEvent<?> event) {
                DirtyState.this.fireEvent(event);
            }
        }, value);
    }

    private final HandlerManager handlers_ = new HandlerManager(this);
    private JavaScriptObject cleanUndoStateToken_;
    private boolean value_;
    private final DocDisplay editor_;
}