org.eclipse.jface.viewers.CheckboxTreeViewer#getContentProvider ( )源码实例Demo

private static void setChecked(final CheckboxTreeViewer tv, Object element) {
  // When user checks a checkbox in the tree, check all its children and mark parent as greyed
  // When a user uncheck a checkbox, mark the subtree as unchecked and ungrayed and if unique
  // sibling parent as grayed.
  DirectoryTreeContentProvider provider = (DirectoryTreeContentProvider) tv.getContentProvider();

  boolean isChecked = tv.getChecked(element);
  if (tv.getGrayed(element)) {
    isChecked = !isChecked;
  }
  tv.setChecked(element, isChecked);
  tv.setGrayed(element, false);
  if (isChecked) {
    tv.setSubtreeChecked(element, true);
  } else {
    tv.setSubtreeChecked(element, false);
  }
  setGrayed(tv, provider.getParent(element));
}
 

private static void setGrayed(CheckboxTreeViewer tv, Object element) {
  if (element == null) {
    return;
  }
  DirectoryTreeContentProvider provider = (DirectoryTreeContentProvider) tv.getContentProvider();
  boolean checked = tv.getChecked(element);
  boolean grayed = false;
  for (Object object : provider.getChildren(element)) {
    grayed = grayed || tv.getGrayed(object) || tv.getChecked(object);
    checked = checked && tv.getChecked(object) && !tv.getGrayed(element);
  }
  if (checked) {
    tv.setChecked(element, true);
    tv.setGrayed(element, false);
  } else if (grayed) {
    tv.setGrayChecked(element, true);
  } else {
    tv.setChecked(element, false);
    tv.setGrayed(element, false);
  }
  setGrayed(tv, provider.getParent(element));
}
 

/**
 * Returns the list of path selected in <code>tv</code>. It returns the list of checked path
 * without the children of the checked path. Each path is returned as a string giving the relative
 * path from the root of the tree.
 */
static ImmutableList<String> getSelectPathsRelativeToRoot(CheckboxTreeViewer tv) {
  DirectoryTreeContentProvider provider = (DirectoryTreeContentProvider) tv.getContentProvider();
  String root = provider.root.getAbsolutePath();
  ImmutableList.Builder<String> builder = ImmutableList.builder();
  for (Object element : tv.getCheckedElements()) {
    if (!tv.getGrayed(element)) {
      Object parent = provider.getParent(element);
      if (parent == null || tv.getGrayed(parent)) {
        // Only add this element if its parent is not selected (so it's the root).
        String path = ((File) element).getAbsolutePath();
        // Strip root from path
        if (path.startsWith(root)) {
          path = path.substring(root.length());
          if (path.startsWith("/")) {
            path = path.substring(1);
          }
          builder.add(path);
        }
      }
    }
  }
  return builder.build();
}
 

/**
 * Set the root of the directory tree view and refresh the view if appropriate
 */
static void setFileTreeRoot(CheckboxTreeViewer tv, File root) {
  DirectoryTreeContentProvider provider = (DirectoryTreeContentProvider) tv.getContentProvider();
  if ((root == null && provider.getRoot() != null) || !root.equals(provider.getRoot())) {
    provider.setRoot(root);
    tv.refresh();
  }
}
 

/**
 * Ensure that the state of the checkbox and its parents are correct.
 *
 * TODO: Create utils method for use in other checkboxes.
 *
 * @param element
 *            Tree element from which the verification needs to be made
 */
private void maintainCheckIntegrity(final Object element) {
    CheckboxTreeViewer checkboxTreeViewer = getCheckboxTreeViewer();
    ITreeContentProvider contentProvider = (ITreeContentProvider) checkboxTreeViewer.getContentProvider();
    boolean allChecked = true;
    boolean oneChecked = false;
    boolean oneGrayed = false;

    for (Object child : contentProvider.getChildren(element)) {
        if (checkboxTreeViewer.testFindItem(child) == null) {
            continue;
        }

        boolean checked = getChecked(child);
        oneChecked |= checked;
        allChecked &= checked;
        oneGrayed |= (checked && getGrayed(child));

        if (oneGrayed || (oneChecked && !allChecked)) {
            setGrayed(element, true);
            setChecked(element, true);
        } else {
            setGrayed(element, false);
            setChecked(element, allChecked);
        }
    }

    Object parentElement = contentProvider.getParent(element);
    if (parentElement != null) {
        maintainCheckIntegrity(parentElement);
    }
}