動態頁面大小更改爲星雲分頁導致IllegelArgumentException

Question

我使用Eclipse Nebula Pagination API。

• 我有9行一個小例子表和2.

• 我顯示最後頁5/5的頁大小。

• 然後，我嘗試將頁面大小從2更改爲10（使用自定義輸入字段）。

的PageListHelper然後試圖獲得與的fromIndex = 10元素範圍爲= 9引起異常的子列表。

List<?> content = list.subList(fromIndex, toIndex); 

我想對於fromIndex有一個缺失檢查，例如，

if (fromIndex > totalSize) { 
    return emptyPageResult; 
} 

https://github.com/eclipse/nebula/blob/34a465c057ca960e9b9c71eb6cbc15d213304b7a/widgets/pagination/org.eclipse.nebula.widgets.pagination/src/org/eclipse/nebula/widgets/pagination/collections/PageListHelper.java

我試圖改變頁面大小之前將當前頁面重置爲1。 但這並沒有幫助。

=>是否允許動態更改頁面大小？有人知道工作嗎？

編輯

我申請了一個錯誤： https://bugs.eclipse.org/bugs/show_bug.cgi?id=511673

Answer 1

我創建了一個自定義的PageResultLoader包括對的fromIndex檢查：

package org.treez.data.table.nebula.nat; 

import java.util.ArrayList; 
import java.util.List; 

import org.eclipse.nebula.widgets.pagination.IPageLoader; 
import org.eclipse.nebula.widgets.pagination.PageableController; 
import org.eclipse.nebula.widgets.pagination.collections.DefaultSortProcessor; 
import org.eclipse.nebula.widgets.pagination.collections.PageResult; 
import org.eclipse.nebula.widgets.pagination.collections.SortProcessor; 
import org.eclipse.swt.SWT; 
import org.treez.core.data.row.Row; 

public class PageResultLoader implements IPageLoader<PageResult<Row>> { 

private List<Row> items; 

public PageResultLoader(List<Row> items) { 
    this.items = items; 
} 

public void setItems(List<Row> items) { 
    this.items = items; 
} 

public List<Row> getItems() { 
    return items; 
} 

@Override 
public PageResult<Row> loadPage(PageableController controller) { 

    SortProcessor processor = DefaultSortProcessor.getInstance(); 
    int sortDirection = controller.getSortDirection(); 
    if (sortDirection != SWT.NONE) { 
     // Sort the list 
     processor.sort(items, controller.getSortPropertyName(), sortDirection); 
    } 
    int totalSize = items.size(); 
    int pageSize = controller.getPageSize(); 
    int pageIndex = controller.getPageOffset(); 

    int fromIndex = pageIndex; 
    if (fromIndex > totalSize) { 
     return new PageResult<Row>(new ArrayList<Row>(), totalSize); 
    } 

    int toIndex = pageIndex + pageSize; 
    if (toIndex > totalSize) { 
     toIndex = totalSize; 
    } 
    List<Row> content = items.subList(fromIndex, toIndex); 
    return new PageResult<Row>(content, totalSize); 
} 

} 

如果其他人也想動態設置頁面大小，我的分頁組件渲染器可能會作爲一個起點：

public class PaginationComponentRenderer extends AbstractPageControllerComposite { 

//#region ATTRIBUTES 

private Label resultLabel; 

private Label first; 

private Label previous; 

private Text currentPageIndexField; 

private Label totalPagesLabel; 

private Label next; 

private Label last; 

private Text pageSizeField; 

private final int maxPageSize = 1000000; 

//#end region 

//#region CONSTRUCTORS 

public PaginationComponentRenderer(Composite parent, int style, PageableController controller) { 
    super(parent, style, controller); 
    refreshEnabled(controller); 
} 

//#end region 

//#region METHODS 

@Override 
protected void createUI(Composite parent) { 

    GridLayout parentLayout = new GridLayout(1, false); 
    parentLayout.verticalSpacing = 0; 
    parentLayout.marginTop = 0; 
    parentLayout.marginBottom = 0; 
    parent.setLayout(parentLayout); 

    GridLayout layout = new GridLayout(1, false); 
    layout.verticalSpacing = 0; 
    layout.marginTop = 0; 
    layout.marginBottom = 0; 
    this.setLayout(layout); 

    createButtonsAndInputFields(parent); 

    createRowLimitForPagesField(parent); 
} 

@SuppressWarnings("checkstyle:magicnumber") 
private void createButtonsAndInputFields(Composite parent) { 

    FormToolkit toolkit = new FormToolkit(Display.getCurrent()); 
    PageableController controller = getController(); 

    Composite rowContainer = toolkit.createComposite(parent); 

    GridLayout layout = new GridLayout(8, false); 
    layout.verticalSpacing = 0; 
    layout.marginTop = 0; 
    layout.marginBottom = 0; 
    rowContainer.setLayout(layout); 
    rowContainer.setLayoutData(new GridData(SWT.FILL, SWT.NONE, true, false)); 

    createRowsLabel(toolkit, rowContainer); 

    toolkit.createLabel(rowContainer, "  Page "); 

    createFirstButton(toolkit, rowContainer, controller); 
    createPreviousButton(toolkit, rowContainer, controller); 

    createCurrentPageField(toolkit, rowContainer); 

    crateNextButton(toolkit, rowContainer, controller); 
    createLastButton(toolkit, rowContainer, controller); 

    createMaxPageLabel(toolkit, rowContainer, controller); 

} 

private void createFirstButton(FormToolkit toolkit, Composite container, PageableController controller) { 

    first = toolkit.createLabel(container, "", SWT.NONE); 
    first.setImage(Activator.getImage("first")); 
    first.addListener(SWT.MouseDown, (e) -> { 
     controller.setCurrentPage(0); 
    }); 
} 

private void createPreviousButton(FormToolkit toolkit, Composite container, PageableController controller) { 
    previous = toolkit.createLabel(container, "", SWT.NONE); 
    previous.setImage(Activator.getImage("previous")); 
    previous.addListener(SWT.MouseDown, (e) -> { 
     controller.setCurrentPage(controller.getCurrentPage() - 1); 
    }); 
} 

@SuppressWarnings("checkstyle:magicnumber") 
private void createCurrentPageField(FormToolkit toolkit, Composite container) { 
    currentPageIndexField = toolkit.createText(container, "1", SWT.NONE); 
    currentPageIndexField.setLayoutData(new GridData(40, 15)); 
    currentPageIndexField.setToolTipText("Page index"); 
    currentPageIndexField.addTraverseListener((e) -> updateCurrentPageIndex()); 
    currentPageIndexField.addFocusListener(new FocusListener() { 

     @Override 
     public void focusLost(FocusEvent e) { 
      updateCurrentPageIndex(); 
     } 

     @Override 
     public void focusGained(FocusEvent e) { 

     } 

    }); 

} 

private void updateCurrentPageIndex() { 
    PageableController controller = getController(); 
    int pageNumberStartingWithOne = getValidPageIndex(); 
    controller.setCurrentPage(pageNumberStartingWithOne - 1); 
    currentPageIndexField.setText("" + pageNumberStartingWithOne); 
} 

private void createMaxPageLabel(FormToolkit toolkit, Composite parent, PageableController controller) { 
    Composite container = toolkit.createComposite(parent); 
    GridLayout layout = new GridLayout(2, false); 
    layout.verticalSpacing = 0; 
    layout.marginTop = 0; 
    layout.marginBottom = 0; 
    container.setLayout(layout); 

    toolkit.createLabel(container, "of"); 
    totalPagesLabel = toolkit.createLabel(container, "" + controller.getTotalPages()); 
} 

private void crateNextButton(FormToolkit toolkit, Composite container, PageableController controller) { 
    next = toolkit.createLabel(container, "", SWT.NONE); 
    next.setImage(Activator.getImage("next")); 
    next.addListener(SWT.MouseDown, (e) -> { 
     controller.setCurrentPage(controller.getCurrentPage() + 1); 
    }); 
} 

private void createLastButton(FormToolkit toolkit, Composite container, PageableController controller) { 
    last = toolkit.createLabel(container, "", SWT.NONE); 
    last.setImage(Activator.getImage("last")); 
    last.addListener(SWT.MouseDown, (e) -> { 
     controller.setCurrentPage(controller.getTotalPages() - 1); 
    }); 
} 

private void createRowsLabel(FormToolkit toolkit, Composite parent) { 
    resultLabel = toolkit.createLabel(parent, ""); //also see method getResultsText 
} 

@SuppressWarnings("checkstyle:magicnumber") 
private void createRowLimitForPagesField(Composite parent) { 

    FormToolkit toolkit = new FormToolkit(Display.getCurrent()); 
    PageableController controller = getController(); 

    Composite container = toolkit.createComposite(parent); 
    GridLayout layout = new GridLayout(3, false); 
    layout.verticalSpacing = 0; 
    layout.marginTop = 0; 
    layout.marginBottom = 0; 

    container.setLayout(layout); 
    GridData gridData = new GridData(SWT.FILL, SWT.FILL, true, false); 
    container.setLayoutData(gridData); 

    //createSpacer(toolkit, container); 

    toolkit.createLabel(container, "Max rows per page: "); 

    pageSizeField = toolkit.createText(container, "" + controller.getPageSize(), SWT.NONE); 
    pageSizeField.setToolTipText("Maximum number of rows per page"); 

    pageSizeField.setLayoutData(new GridData(40, 15)); 

    pageSizeField.addTraverseListener((e) -> upatePageSize()); 
    pageSizeField.addFocusListener(new FocusListener() { 

     @Override 
     public void focusLost(FocusEvent e) { 
      upatePageSize(); 
     } 

     @Override 
     public void focusGained(FocusEvent arg0) {} 

    }); 
} 

private void upatePageSize() { 
    PageableController controller = getController(); 
    int pageSize = getValidPageSize(); 
    pageSizeField.setText("" + pageSize); 
    controller.setPageSize(pageSize); 

    updateCurrentPageIndex(); 
} 

@Override 
public void pageIndexChanged(int oldPageNumber, int newPageNumber, PageableController controller) { 
    currentPageIndexField.setText("" + (controller.getCurrentPage() + 1)); 
    refreshEnabled(controller); 
} 

@Override 
public void totalElementsChanged(long oldTotalElements, long newTotalElements, PageableController controller) { 
    totalPagesLabel.setText("" + controller.getTotalPages()); 
    upatePageSize(); 
    refreshEnabled(controller); 
} 

@Override 
public void pageSizeChanged(int oldPageSize, int newPageSize, PageableController controller) { 
    pageSizeField.setText("" + controller.getPageSize()); 
    totalPagesLabel.setText("" + controller.getTotalPages()); 
    refreshEnabled(controller); 
} 

@Override 
public void sortChanged(
     String oldPopertyName, 
     String propertyName, 
     int oldSortDirection, 
     int sortDirection, 
     PageableController paginationController) { 
    // Do nothing 
} 

private int getValidPageIndex() { 
    PageableController controller = getController(); 
    int currentPageIndex = controller.getCurrentPage() + 1; 
    int pageIndex = currentPageIndex; 
    try { 
     pageIndex = Integer.parseInt(currentPageIndexField.getText()); 
    } catch (NumberFormatException exception) {} 

    if (pageIndex < 1) { 
     return currentPageIndex; 
    } 

    int totalPages = controller.getTotalPages(); 
    if (pageIndex > totalPages) { 
     return totalPages; 
    } 

    return pageIndex; 
} 

private int getValidPageSize() { 

    PageableController controller = getController(); 
    int currentPageSize = controller.getPageSize(); 
    int pageSize = currentPageSize; 
    try { 
     pageSize = Integer.parseInt(pageSizeField.getText()); 
    } catch (NumberFormatException exception) {} 

    if (pageSize < 1) { 
     return currentPageSize; 
    } 

    if (pageSize > maxPageSize) { 
     return currentPageSize; 
    } 

    return pageSize; 
} 

private void refreshEnabled(PageableController controller) { 
    resultLabel.setText(getResultsText(controller)); 

    boolean hasPrevious = controller.hasPreviousPage(); 
    first.setEnabled(hasPrevious); 
    previous.setEnabled(hasPrevious); 

    boolean hasNext = controller.hasNextPage(); 
    next.setEnabled(hasNext); 
    last.setEnabled(hasNext); 
} 

private static String getResultsText(PageableController controller) { 
    int start = controller.getPageOffset() + 1; 
    int end = start + controller.getPageSize() - 1; 
    long total = controller.getTotalElements(); 
    if (end > total) { 
     end = (int) total; 
    } 

    return "Rows " + start + "..." + end + " of " + total; 

} 

//#end region 

}