poi/poi-ooxml/src/main/java/org/apache/poi/xslf/usermodel/XSLFDiagram.java

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   this work for additional information regarding copyright ownership.
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package org.apache.poi.xslf.usermodel;

import com.microsoft.schemas.office.drawing.x2008.diagram.CTGroupShape;
import com.microsoft.schemas.office.drawing.x2008.diagram.CTShape;
import org.apache.poi.ooxml.POIXMLDocumentPart;
import org.apache.poi.util.Beta;
import org.apache.xmlbeans.XmlObject;
import org.openxmlformats.schemas.drawingml.x2006.diagram.CTRelIds;
import org.openxmlformats.schemas.drawingml.x2006.main.CTGraphicalObjectData;
import org.openxmlformats.schemas.drawingml.x2006.main.CTGroupShapeProperties;
import org.openxmlformats.schemas.drawingml.x2006.main.CTTextParagraph;
import org.openxmlformats.schemas.presentationml.x2006.main.CTApplicationNonVisualDrawingProps;
import org.openxmlformats.schemas.presentationml.x2006.main.CTGraphicalObjectFrame;
import org.openxmlformats.schemas.presentationml.x2006.main.CTGroupShapeNonVisual;
import org.openxmlformats.schemas.presentationml.x2006.main.CTShapeNonVisual;

import javax.xml.namespace.QName;
import java.awt.geom.Rectangle2D;
import java.util.ArrayList;
import java.util.List;

/**
 * Representation of a DrawingML Diagram
 * <p>
 * This class converts the diagram to an {@link XSLFGroupShape} accessible via {@link #getGroupShape()}. The underlying
 * {@link XSLFDiagramDrawing} used to create the group shape is accessible via {@link #getDiagramDrawing()}.
 * <p>
 * In pptx files, these diagrams are generated by creating SmartArt. When a pptx has SmartArt, a directory with the
 * following structure is created:
 *
 * <pre>
 * ppt/
 *   diagrams/
 *     data#.xml
 *     drawing#.xml^
 *     colors#.xml
 *     quickStyle#.xml
 *     layout#.xml
 *     rels/
 *       data#.xml.rels
 *       drawing#.xml.rels
 * </pre>
 * <p>
 * ^The `drawing#.xml` file is not in the OpenXML spec. It was added as an extension by Microsoft, namespace:
 * http://schemas.microsoft.com/office/drawing/2008/diagram
 * <p>
 * The drawing#.xml file contains the rendered output of the diagram. This class reads the underlying drawing#.xml and
 * converts it to a {@link XSLFGroupShape}.
 * <p>
 * The data, drawing, colors, and quickStyle files are in the OpenXML spec. These contain the instructions that define
 * how to render the diagram. Rendering diagrams from these files is not trivial, they support for loops, if/elses, etc.
 * Integrating such a change into POI would be quite sophisticated and challenging.
 *
 * @since POI 5.2.3
 */
@Beta
public class XSLFDiagram extends XSLFGraphicFrame {

    public static final String DRAWINGML_DIAGRAM_URI = "http://schemas.openxmlformats.org/drawingml/2006/diagram";
    private final XSLFDiagramDrawing _drawing;
    private final XSLFDiagramGroupShape _groupShape;

    /* package protected */ XSLFDiagram(CTGraphicalObjectFrame shape, XSLFSheet sheet) {
        super(shape, sheet);
        _drawing = readDiagramDrawing(shape, sheet);
        _groupShape = initGroupShape();
    }

    private static boolean hasTextContent(CTShape msShapeCt) {
        if (msShapeCt.getTxBody() == null || msShapeCt.getTxXfrm() == null) {
            return false;
        }
        // A shape has text content when there is at least 1 paragraph with 1 paragraph run list
        List<CTTextParagraph> paragraphs = msShapeCt.getTxBody().getPList();
        return paragraphs.stream()
                .flatMap(p -> p.getRList().stream())
                .anyMatch(run -> run.getT() != null && !run.getT().trim().isEmpty());
    }

    private static XSLFDiagramDrawing readDiagramDrawing(CTGraphicalObjectFrame shape, XSLFSheet sheet) {
        CTGraphicalObjectData graphicData = shape.getGraphic().getGraphicData();
        XmlObject[] children = graphicData.selectChildren(new QName(DRAWINGML_DIAGRAM_URI, "relIds"));

        if (children.length == 0) {
            return null;
        }

        // CTRelIds doesn't contain a relationship to the drawing#.xml
        // But it has the same name as the other data#.xml, layout#.xml, etc.
        CTRelIds relIds = (CTRelIds) children[0];
        POIXMLDocumentPart dataModelPart = sheet.getRelationById(relIds.getDm());
        if (dataModelPart == null) {
            return null;
        }
        String dataPartName = dataModelPart.getPackagePart().getPartName().getName();
        String drawingPartName = dataPartName.replace("data", "drawing");
        for (POIXMLDocumentPart.RelationPart rp : sheet.getRelationParts()) {
            if (drawingPartName.equals(rp.getDocumentPart().getPackagePart().getPartName().getName())) {
                if (rp.getDocumentPart() instanceof XSLFDiagramDrawing) {
                    return rp.getDocumentPart();
                }
            }
        }
        return null;
    }

    /**
     * Returns the underlying {@link XSLFDiagramDrawing} used to create this diagram.
     * <p>
     * NOTE: Modifying this drawing will not update the groupShape returned from {@link #getGroupShape()}.
     */
    public XSLFDiagramDrawing getDiagramDrawing() {
        return _drawing;
    }

    /**
     * Returns the diagram represented as a grouped shape.
     */
    public XSLFDiagramGroupShape getGroupShape() {
        return _groupShape;
    }

    // If the shape has text, two XSLFShapes are created. One shape element and one textbox element.
    private List<org.openxmlformats.schemas.presentationml.x2006.main.CTShape> convertShape(CTShape msShapeCt) {
        org.openxmlformats.schemas.presentationml.x2006.main.CTShape shapeCt
                = org.openxmlformats.schemas.presentationml.x2006.main.CTShape.Factory.newInstance();

        // The fields on MS CTShape largely re-use the underlying openxml classes.
        // We just copy the fields from the MS CTShape to the openxml CTShape
        shapeCt.setStyle(msShapeCt.getStyle());
        shapeCt.setSpPr(msShapeCt.getSpPr());

        CTShapeNonVisual nonVisualCt = shapeCt.addNewNvSpPr();
        nonVisualCt.setCNvPr(msShapeCt.getNvSpPr().getCNvPr());
        nonVisualCt.setCNvSpPr(msShapeCt.getNvSpPr().getCNvSpPr());
        nonVisualCt.setNvPr(CTApplicationNonVisualDrawingProps.Factory.newInstance());
        shapeCt.setNvSpPr(nonVisualCt);

        ArrayList<org.openxmlformats.schemas.presentationml.x2006.main.CTShape> shapes = new ArrayList<>();
        shapes.add(shapeCt);

        if (hasTextContent(msShapeCt)) {
            org.openxmlformats.schemas.presentationml.x2006.main.CTShape textShapeCT = convertText(msShapeCt, nonVisualCt);
            shapes.add(textShapeCT);
        }

        return shapes;
    }

    private org.openxmlformats.schemas.presentationml.x2006.main.CTShape convertText(CTShape msShapeCt, CTShapeNonVisual nonVisualCt) {
        org.openxmlformats.schemas.presentationml.x2006.main.CTShape textShapeCT
                = org.openxmlformats.schemas.presentationml.x2006.main.CTShape.Factory.newInstance();

        // SmartArt shapes define a separate `txXfrm` property for the placement of text inside the shape
        // We can't easily (is it even possible?) set a separate xfrm for the text on the openxml CTShape.
        // Instead, we create a separate textbox shape with the same xfrm.
        org.openxmlformats.schemas.drawingml.x2006.main.CTShapeProperties textShapeProps = textShapeCT.addNewSpPr();

        textShapeCT.setTxBody(msShapeCt.getTxBody());
        textShapeCT.setStyle(msShapeCt.getStyle());
        // Create a copy of the nonVisualCt when setting it for the text box.
        // If we shared the one object, a consumer may be surprised that updating the text shape properties
        // also updates the parent shape.
        textShapeCT.setNvSpPr((CTShapeNonVisual) nonVisualCt.copy());
        textShapeCT.getNvSpPr().getCNvSpPr().setTxBox(true);

        textShapeProps.setXfrm(msShapeCt.getTxXfrm());
        int shapeRotation = msShapeCt.getSpPr().getXfrm().getRot();
        int textRotation = msShapeCt.getTxXfrm().getRot();
        if (textRotation != 0) {
            // SmartArt diagrams (e.g. hexagon) have rotated shapes and the txXfrm can change the rotation for visual
            // reasons. We perform that same calculation here again and calculate a new rotation for the text box.
            int resolvedRotation = shapeRotation + textRotation;
            textShapeProps.getXfrm().setRot(resolvedRotation);
        }

        return textShapeCT;
    }

    private XSLFDiagramGroupShape initGroupShape() {
        XSLFDiagramDrawing drawing = getDiagramDrawing();
        if (drawing == null || drawing.getDrawingDocument() == null) {
            return null;
        }

        CTGroupShape msGroupShapeCt = drawing.getDrawingDocument().getDrawing().getSpTree();
        if (msGroupShapeCt == null || msGroupShapeCt.getSpList().isEmpty()) {
            return null;
        }
        return convertMsGroupToGroupShape(msGroupShapeCt, drawing);
    }

    private XSLFDiagramGroupShape convertMsGroupToGroupShape(CTGroupShape msGroupShapeCt, XSLFDiagramDrawing drawing) {
        org.openxmlformats.schemas.presentationml.x2006.main.CTGroupShape groupShapeCt
                = org.openxmlformats.schemas.presentationml.x2006.main.CTGroupShape.Factory.newInstance();

        CTGroupShapeProperties groupShapePropsCt = groupShapeCt.addNewGrpSpPr();

        CTGroupShapeNonVisual groupShapeNonVisualCt = groupShapeCt.addNewNvGrpSpPr();
        groupShapeNonVisualCt.setCNvPr(msGroupShapeCt.getNvGrpSpPr().getCNvPr());
        groupShapeNonVisualCt.setCNvGrpSpPr(msGroupShapeCt.getNvGrpSpPr().getCNvGrpSpPr());
        groupShapeNonVisualCt.setNvPr(CTApplicationNonVisualDrawingProps.Factory.newInstance());

        for (CTShape msShapeCt : msGroupShapeCt.getSpList()) {
            List<org.openxmlformats.schemas.presentationml.x2006.main.CTShape> shapes = convertShape(msShapeCt);
            groupShapeCt.getSpList().addAll(shapes);
        }

        Rectangle2D anchor = super.getAnchor();
        Rectangle2D interiorAnchor = new Rectangle2D.Double(0, 0, anchor.getWidth(), anchor.getHeight());

        XSLFDiagramGroupShape groupShape = new XSLFDiagramGroupShape(groupShapeCt, getSheet(), drawing);
        groupShape.setAnchor(anchor);
        groupShape.setInteriorAnchor(interiorAnchor);
        groupShape.setRotation(super.getRotation());
        return groupShape;
    }

    /**
     * Simple wrapper around XSLFGroupShape to enable accessing underlying diagram relations correctly.
     * <p>
     * Diagrams store relationships to media in `drawing#.xml.rels`. These relationships are accessible using
     * {@link #getRelationById(String)}.
     */
    static class XSLFDiagramGroupShape extends XSLFGroupShape {

        private XSLFDiagramDrawing diagramDrawing;

        protected XSLFDiagramGroupShape(org.openxmlformats.schemas.presentationml.x2006.main.CTGroupShape shape,
                                        XSLFSheet sheet) {
            super(shape, sheet);
        }

        private XSLFDiagramGroupShape(org.openxmlformats.schemas.presentationml.x2006.main.CTGroupShape shape,
                                      XSLFSheet sheet,
                                      XSLFDiagramDrawing diagramDrawing) {
            super(shape, sheet);
            this.diagramDrawing = diagramDrawing;
        }

        POIXMLDocumentPart getRelationById(String id) {
            return diagramDrawing.getRelationById(id);
        }
    }
}