DynamicStyleKey.java

/*
 * This program is free software; you can redistribute it and/or modify it under the
 *  terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
 *  Foundation.
 *
 *  You should have received a copy of the GNU Lesser General Public License along with this
 *  program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
 *  or from the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 *  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 Lesser General Public License for more details.
 *
 *  Copyright (c) 2006 - 2013 Pentaho Corporation..  All rights reserved.
 */

package org.pentaho.reporting.engine.classic.core.modules.output.fast.template;

import org.pentaho.reporting.engine.classic.core.AttributeNames;
import org.pentaho.reporting.engine.classic.core.Band;
import org.pentaho.reporting.engine.classic.core.ReportElement;
import org.pentaho.reporting.engine.classic.core.Section;
import org.pentaho.reporting.engine.classic.core.function.ExpressionRuntime;
import org.pentaho.reporting.engine.classic.core.layout.style.SimpleStyleSheet;
import org.pentaho.reporting.engine.classic.core.style.StyleKey;
import org.pentaho.reporting.engine.classic.core.util.AbstractStructureVisitor;
import org.pentaho.reporting.engine.classic.core.util.InstanceID;
import org.pentaho.reporting.libraries.base.util.ArgumentNullException;
import org.pentaho.reporting.libraries.base.util.ObjectUtilities;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

public class DynamicStyleKey {
  private static class StyleInfoCollection {
    private static class StyleInfo {
      private int styleKeyIndex;
      private Object styleValue;

      private StyleInfo( final int styleKeyIndex, final Object styleValue ) {
        this.styleKeyIndex = styleKeyIndex;
        this.styleValue = styleValue;
      }

      public boolean equals( final Object o ) {
        if ( this == o ) {
          return true;
        }
        if ( o == null || getClass() != o.getClass() ) {
          return false;
        }

        final StyleInfo styleInfo = (StyleInfo) o;

        if ( styleKeyIndex != styleInfo.styleKeyIndex ) {
          return false;
        }
        if ( styleValue != null ? !styleValue.equals( styleInfo.styleValue ) : styleInfo.styleValue != null ) {
          return false;
        }
        return true;
      }

      public int hashCode() {
        int result = styleKeyIndex;
        result = 31 * result + ( styleValue != null ? styleValue.hashCode() : 0 );
        return result;
      }
    }

    private ArrayList<StyleInfo> styleInfo;
    private Integer hashCode;
    private long styleChangeTracker;
    private boolean nullValue;

    private StyleInfoCollection( int length, boolean nullValue ) {
      this.styleInfo = new ArrayList<StyleInfo>( length );
      this.nullValue = nullValue;
    }

    public void add( StyleKey k, Object o ) {
      styleInfo.add( new StyleInfo( k.getIdentifier(), o ) );
    }

    public long getStyleChangeTracker() {
      return styleChangeTracker;
    }

    private void setStyleChangeTracker( final long styleChangeTracker ) {
      this.styleChangeTracker = styleChangeTracker;
    }

    public boolean equals( final Object o ) {
      if ( this == o ) {
        return true;
      }
      if ( o == null || getClass() != o.getClass() ) {
        return false;
      }
      final StyleInfoCollection that = (StyleInfoCollection) o;
      if ( ObjectUtilities.equal( hashCode, that.hashCode ) == false ) {
        return false;
      }

      if ( !styleInfo.equals( that.styleInfo ) ) {
        return false;
      }
      if ( nullValue != that.nullValue ) {
        return false;
      }
      return true;
    }

    public int hashCode() {
      if ( hashCode == null ) {
        hashCode = styleInfo.hashCode() + 23 * ( nullValue ? 1 : 0 );
      }
      return hashCode;
    }
  }

  private InstanceID rootBandId;
  private Map<InstanceID, StyleInfoCollection> dynamicStylePerElement;
  private Integer hashCode;

  private DynamicStyleKey( final InstanceID rootBandId,
      final Map<InstanceID, StyleInfoCollection> dynamicStylePerElement ) {
    this.rootBandId = rootBandId;
    this.dynamicStylePerElement = dynamicStylePerElement;
  }

  public boolean equals( final Object o ) {
    if ( this == o ) {
      return true;
    }
    if ( o == null || getClass() != o.getClass() ) {
      return false;
    }

    final DynamicStyleKey that = (DynamicStyleKey) o;
    if ( ObjectUtilities.equal( hashCode, that.hashCode ) == false ) {
      return false;
    }

    if ( !dynamicStylePerElement.equals( that.dynamicStylePerElement ) ) {
      return false;
    }
    if ( !rootBandId.equals( that.rootBandId ) ) {
      return false;
    }

    return true;
  }

  public int hashCode() {
    if ( hashCode == null ) {
      int result = rootBandId.hashCode();
      result = 31 * result + dynamicStylePerElement.hashCode();
      hashCode = result;
    }
    return hashCode;
  }

  public static DynamicStyleKey create( Band band, ExpressionRuntime runtime ) {
    Map<InstanceID, StyleInfoCollection> style = new DynamicStyleKeyProducer().collect( band, runtime );
    return new DynamicStyleKey( band.getObjectID(), style );
  }

  private static class DynamicStyleKeyProducer extends AbstractStructureVisitor {
    private HashMap<InstanceID, StyleKey[]> dynamicTemplateInfo;
    private HashMap<InstanceID, StyleInfoCollection> styleInfo;
    private ExpressionRuntime runtime;

    public Map<InstanceID, StyleInfoCollection> collect( Band band, ExpressionRuntime runtime ) {
      ArgumentNullException.validate( "band", band );
      ArgumentNullException.validate( "runtime", runtime );

      this.runtime = runtime;
      dynamicTemplateInfo =
          (HashMap<InstanceID, StyleKey[]>) band.getAttribute( AttributeNames.Internal.NAMESPACE,
              AttributeNames.Internal.FAST_EXPORT_DYNAMIC_STASH );
      if ( dynamicTemplateInfo == null ) {
        return Collections.emptyMap();
      }
      styleInfo = new HashMap<InstanceID, StyleInfoCollection>();
      inspectElement( band );
      traverseSection( band );
      return styleInfo;
    }

    protected void traverseSection( final Section section ) {
      traverseSectionWithoutSubReports( section );
    }

    protected void inspectElement( final ReportElement element ) {
      StyleKey[] styleIndex = dynamicTemplateInfo.get( element.getObjectID() );
      if ( styleIndex == null || styleIndex.length == 0 ) {
        return;
      }

      Object value = element.getElementType().getValue( runtime, element );
      boolean empty = isEmpty( value );

      StyleInfoCollection lastCollection =
          (StyleInfoCollection) element.getAttribute( AttributeNames.Internal.NAMESPACE,
              AttributeNames.Internal.FAST_EXPORT_ELEMENT_STASH );
      SimpleStyleSheet computedStyle = element.getComputedStyle();
      if ( lastCollection != null && lastCollection.getStyleChangeTracker() == computedStyle.getChangeTrackerHash()
          && lastCollection.nullValue == empty ) {
        // no changes
        styleInfo.put( element.getObjectID(), lastCollection );
        return;
      }

      StyleInfoCollection collection = new StyleInfoCollection( styleIndex.length, empty );
      collection.setStyleChangeTracker( computedStyle.getChangeTrackerHash() );
      for ( StyleKey styleKey : styleIndex ) {
        collection.add( styleKey, computedStyle.getStyleProperty( styleKey ) );
      }
      styleInfo.put( element.getObjectID(), collection );
    }

    private boolean isEmpty( Object o ) {
      if ( o == null ) {
        return true;
      }
      if ( "".equals( o ) ) {
        return true;
      }
      return false;
    }
  }

}