javax.swing.plaf.TextUI#getRootView ( )源码实例Demo

/**
 * Get first view in the hierarchy that is an instance of the given class.
 * It allows to skip various wrapper-views around the doc-view that holds
 * the child views for the lines.
 *
 * @param component component from which the root view is fetched.
 * @param rootViewClass class of the view to return.
 * @return view being instance of the requested class or null if there
 *  is not one.
 */
public static View getRootView(JTextComponent component, Class rootViewClass) {
    View view = null;
    TextUI textUI = component.getUI();
    if (textUI != null) {
        view = textUI.getRootView(component);
        while (view != null && !rootViewClass.isInstance(view)
            && view.getViewCount() == 1 // must be wrapper view
        ) {
            view = view.getView(0); // get the only child
        }
    }
    
    return view;
}
 

public static DocumentView get(JTextComponent component) {
    TextUI textUI = component.getUI();
    if (textUI != null) {
        View rootView = textUI.getRootView(component);
        if (rootView != null && rootView.getViewCount() > 0) {
            View view = rootView.getView(0);
            if (view instanceof DocumentView) {
                return (DocumentView)view;
            }
        }
    }
    return null;
}
 

public void actionPerformed(ActionEvent evt, JTextComponent target) {
    AbstractDocument adoc = (AbstractDocument)target.getDocument();

    // Dump fold hierarchy
    FoldHierarchy hierarchy = FoldHierarchy.get(target);
    adoc.readLock();
    try {
        hierarchy.lock();
        try {
            /*DEBUG*/System.err.println("FOLD HIERARCHY DUMP:\n" + hierarchy); // NOI18N
            TokenHierarchy<?> th = TokenHierarchy.get(adoc);
            /*DEBUG*/System.err.println("TOKEN HIERARCHY DUMP:\n" + (th != null ? th : "<NULL-TH>")); // NOI18N

        } finally {
            hierarchy.unlock();
        }
    } finally {
        adoc.readUnlock();
    }

    View rootView = null;
    TextUI textUI = target.getUI();
    if (textUI != null) {
        rootView = textUI.getRootView(target); // Root view impl in BasicTextUI
        if (rootView != null && rootView.getViewCount() == 1) {
            rootView = rootView.getView(0); // Get DocumentView
        }
    }
    if (rootView != null) {
        String rootViewDump = (rootView instanceof DocumentView)
                ? ((DocumentView)rootView).toStringDetail()
                : rootView.toString();
        /*DEBUG*/System.err.println("DOCUMENT VIEW: " + System.identityHashCode(rootView) + // NOI18N
                "\n" + rootViewDump); // NOI18N
        int caretOffset = target.getCaretPosition();
        int caretViewIndex = rootView.getViewIndex(caretOffset, Position.Bias.Forward);
        /*DEBUG*/System.err.println("caretOffset=" + caretOffset + ", caretViewIndex=" + caretViewIndex); // NOI18N
        if (caretViewIndex >= 0 && caretViewIndex < rootView.getViewCount()) {
            View caretView = rootView.getView(caretViewIndex);
            /*DEBUG*/System.err.println("caretView: " + caretView); // NOI18N
        }
        /*DEBUG*/System.err.println(FixLineSyntaxState.lineInfosToString(adoc));
        // Check the hierarchy correctness
        //org.netbeans.editor.view.spi.ViewUtilities.checkViewHierarchy(rootView);
    }
    
    if (adoc instanceof BaseDocument) {
        /*DEBUG*/System.err.println("DOCUMENT:\n" + ((BaseDocument)adoc).toStringDetail()); // NOI18N
    }
}
 

private int definitionPreferredWidth() {
  TextUI ui = myEditorPane.getUI();
  View view = ui.getRootView(myEditorPane);
  View definition = findDefinition(view);
  return definition != null ? (int)definition.getPreferredSpan(View.X_AXIS) : -1;
}