easyexcel/src/main/java/com/alibaba/excel/write/style/AbstractVerticalCellStyleStrategy.java

package com.alibaba.excel.write.style;

import java.util.List;

import com.alibaba.excel.metadata.Head;
import com.alibaba.excel.metadata.data.WriteCellData;
import com.alibaba.excel.write.handler.context.CellWriteHandlerContext;
import com.alibaba.excel.write.metadata.style.WriteCellStyle;

import org.apache.commons.collections4.CollectionUtils;

/**
 * Use the same style for the column
 *
 * @author Jiaju Zhuang
 */
public abstract class AbstractVerticalCellStyleStrategy extends AbstractCellStyleStrategy {

    @Override
    protected void setHeadCellStyle(CellWriteHandlerContext context) {
        if (!continueProcessing(context)) {
            return;
        }
        WriteCellData<?> cellData = context.getCellDataList().get(0);
        cellData.setWriteCellStyle(headCellStyle(context.getHeadData()));
    }

    @Override
    protected void setContentCellStyle(CellWriteHandlerContext context) {
        if (!continueProcessing(context)) {
            return;
        }
        WriteCellData<?> cellData = context.getCellDataList().get(0);
        cellData.setWriteCellStyle(contentCellStyle(context));
    }

    /**
     * Returns the column width corresponding to each column head.
     *
     * @param context
     * @return
     */
    protected WriteCellStyle contentCellStyle(CellWriteHandlerContext context) {
        return contentCellStyle(context.getHeadData());
    }

    /**
     * Returns the column width corresponding to each column head
     *
     * @param head Nullable
     * @return
     */
    protected abstract WriteCellStyle headCellStyle(Head head);

    /**
     * Returns the column width corresponding to each column head
     *
     * @param head Nullable
     * @return
     */
    protected WriteCellStyle contentCellStyle(Head head) {
        throw new UnsupportedOperationException(
            "One of the two methods 'contentCellStyle(Cell cell, Head head, Integer relativeRowIndex)' and "
                + "'contentCellStyle(Head head)' must be implemented.");
    }

    protected boolean continueProcessing(CellWriteHandlerContext context) {
        List<WriteCellData<?>> cellDataList = context.getCellDataList();
        if (CollectionUtils.isEmpty(cellDataList) || cellDataList.size() > 1) {
            return false;
        }
        return context.getHeadData() != null;
    }
}