javax.swing.text.Element#getElementIndex ( )源码实例Demo

/** The operation to perform when this action is triggered. */
public void actionPerformed(ActionEvent e) {
    JTextComponent target = getTextComponent(e);
    if (target != null) {
        Document doc = target.getDocument();
        Element map = doc.getDefaultRootElement();
        int offs = target.getCaretPosition();
        int lineIndex = map.getElementIndex(offs);
        int lineEnd = map.getElement(lineIndex).getEndOffset() - 1;

        if (select) {
            target.moveCaretPosition(lineEnd);
        } else {
            target.setCaretPosition(lineEnd);
        }
    }            
}
 

@Override
public Shape modelToView(int pos, Shape a, Position.Bias b) throws BadLocationException {
    // line coordinates
    Document doc = getDocument();
    Element map = getElement();
    int lineIndex = map.getElementIndex(pos);
    if (lineIndex < 0) {
        return lineToRect(a, 0);
    }
    Rectangle lineArea = lineToRect(a, lineIndex);

    // determine span from the start of the line
    int tabBase = lineArea.x;
    Element line = map.getElement(lineIndex);
    int p0 = line.getStartOffset();
    Segment s = new Segment();
    doc.getText(p0, pos - p0, s);
    int xOffs = UniTools.getTabbedTextWidth(s, metrics, tabBase, this,p0);

    // fill in the results and return
    lineArea.x += xOffs;
    lineArea.width = 1;
    lineArea.height = metrics.getHeight();
    return lineArea;
}
 

private String getLineNumbersText() {
    final int caretPosition = textArea.getDocument().getLength();
    final Element root = textArea.getDocument().getDefaultRootElement();
    final StringBuilder builder = new StringBuilder();
    builder.append("1").append(System.lineSeparator());

    for (int elementIndex = 2; elementIndex < root.getElementIndex(caretPosition) + 2; elementIndex++) {
        builder.append(elementIndex).append(System.lineSeparator());
    }

    return builder.toString();
}
 

static int getLineNumberForIndex(final Accessible a, int index) {
    final Accessible sa = CAccessible.getSwingAccessible(a);
    if (!(sa instanceof JTextComponent)) return -1;

    final JTextComponent jc = (JTextComponent) sa;
    final Element root = jc.getDocument().getDefaultRootElement();

    // treat -1 special, returns the current caret position
    if (index == -1) index = jc.getCaretPosition();

    // Determine line number (can be -1)
    return root.getElementIndex(index);
}
 

static int getLineNumberForIndex(final Accessible a, int index) {
    final Accessible sa = CAccessible.getSwingAccessible(a);
    if (!(sa instanceof JTextComponent)) return -1;

    final JTextComponent jc = (JTextComponent) sa;
    final Element root = jc.getDocument().getDefaultRootElement();

    // treat -1 special, returns the current caret position
    if (index == -1) index = jc.getCaretPosition();

    // Determine line number (can be -1)
    return root.getElementIndex(index);
}
 

@Override
public void caretUpdate(CaretEvent e) {
	int caretPosition = codeArea.getCaretPosition();
	Element root = codeArea.getDocument().getDefaultRootElement();
	int currentLine = root.getElementIndex(caretPosition);
	if (lastLine != currentLine) {
		repaint();
		lastLine = currentLine;
	}
}
 

static int getLineNumberForIndex(final Accessible a, int index) {
    final Accessible sa = CAccessible.getSwingAccessible(a);
    if (!(sa instanceof JTextComponent)) return -1;

    final JTextComponent jc = (JTextComponent) sa;
    final Element root = jc.getDocument().getDefaultRootElement();

    // treat -1 special, returns the current caret position
    if (index == -1) index = jc.getCaretPosition();

    // Determine line number (can be -1)
    return root.getElementIndex(index);
}
 

static int getLineNumberForIndex(final Accessible a, int index) {
    final Accessible sa = CAccessible.getSwingAccessible(a);
    if (!(sa instanceof JTextComponent)) return -1;

    final JTextComponent jc = (JTextComponent) sa;
    final Element root = jc.getDocument().getDefaultRootElement();

    // treat -1 special, returns the current caret position
    if (index == -1) index = jc.getCaretPosition();

    // Determine line number (can be -1)
    return root.getElementIndex(index);
}
 

private View getExpandedView(){
    Element parentElem = getElement().getParentElement();
    int sei = parentElem.getElementIndex(getStartOffset());
    int so = parentElem.getElement(sei).getStartOffset();
    
    int eei = parentElem.getElementIndex(getEndOffset());
    int eo = parentElem.getElement(eei).getEndOffset();
    
    LockView fakeView = new LockView(
    new DrawEngineFakeDocView(parentElem, so, eo, false, true)
    );
    RootView rootView = new RootView();
    rootView.setView(fakeView);
    return fakeView;
}
 

static int getLineNumberForIndex(final Accessible a, int index) {
    final Accessible sa = CAccessible.getSwingAccessible(a);
    if (!(sa instanceof JTextComponent)) return -1;

    final JTextComponent jc = (JTextComponent) sa;
    final Element root = jc.getDocument().getDefaultRootElement();

    // treat -1 special, returns the current caret position
    if (index == -1) index = jc.getCaretPosition();

    // Determine line number (can be -1)
    return root.getElementIndex(index);
}
 

private void processChangedLines(int offset, int length) throws BadLocationException {
  Element root = getDefaultRootElement();
  String content = getText(0, getLength());
  int startLine = root.getElementIndex(offset);
  int endLine = root.getElementIndex(offset + length);
  for (int i = startLine; i <= endLine; i++) {
    applyHighlighting(content, i);
  }
}
 

/** Count of rows between these two positions */
public static int getLineCount(@NonNull LineDocument doc, int startOffset, int endOffset) {
    if (startOffset > endOffset) {
        return 0;
    }
    Element lineRoot = doc.getParagraphElement(0).getParentElement();
    return lineRoot.getElementIndex(endOffset) - lineRoot.getElementIndex(startOffset) + 1;
}
 

private int getLineAtPoint(int y) {
  Element root = textArea.getDocument().getDefaultRootElement();
  int pos = textArea.viewToModel(new Point(0, y));
  // Java 9: int pos = textArea.viewToModel2D(new Point(0, y));
  return root.getElementIndex(pos);
}
 

private int getLineStart(BaseDocument doc, int offset) {
    Element rootElement = doc.getDefaultRootElement();
    int lineNumber = rootElement.getElementIndex(offset);
    return lineNumber < 0 ? lineNumber : rootElement.getElement(lineNumber).getStartOffset();
}
 

private int getLineEnd(BaseDocument doc, int offset) {
    Element rootElement = doc.getDefaultRootElement();
    int lineNumber = rootElement.getElementIndex(offset);
    return lineNumber < 0 ? lineNumber : rootElement.getElement(lineNumber).getEndOffset();
}
 

private static int followedPosition(JTextComponent tc) {
    Element root = tc.getDocument().getDefaultRootElement();
    return root.getElementIndex(tc.getCaretPosition()) * 6;
}
 

/**
     * Loads child views in a custom way.
     *
     * @param index index at which the views should be added/replaced.
     * @param removeLength number of removed children views. It is useful
     *  when rebuilding children for a portion of the view.
     * @param startOffset starting offset from which the loading starts.
     * @param endOffset ending offset where the loading ends.
     */
    protected void customReloadChildren(int index, int removeLength,
    int startOffset, int endOffset) {

        View[] added = null;
        ViewFactory f = getViewFactory();
        // Null view factory can mean that one of the grand parents is already disconnected
        // from the view hierarchy. No added children for null factory.
        
        if (f != null) {
            Element elem = getElement();

            int elementCount = elem.getElementCount();
            int elementIndex = (elem != null) ? elem.getElementIndex(startOffset) : -1;
            if (elementIndex >= elementCount) {
                return; // Create no after last element
            }
            List childViews = new ArrayList();
            int viewCount = getViewCount();

            loop:
            while (startOffset < endOffset) {
                // Create custom child
                View childView = createCustomView(f, startOffset, endOffset, elementIndex);
                if (childView == null) {
                    throw new IllegalStateException("No view created for area (" // NOI18N
                        + startOffset + ", " + endOffset + ")"); // NOI18N
                }

                // Assuming childView.getStartOffset() is at startOffset
                childViews.add(childView);

                // Update elementIndex
                int childViewEndOffset = childView.getEndOffset();
                while (childViewEndOffset > endOffset) {
/*                    throw new IllegalStateException(
                        "childViewEndOffset=" + childViewEndOffset // NOI18N
                        + " > endOffset=" + endOffset // NOI18N
                    );
 */
                    /* The created child view interferes with a view
                     * that is still present and which is not planned
                     * to be removed.
                     * This can happen e.g. when a fold hierarchy change
                     * (caused by a document change) is fired
                     * prior to the document change gets fired
                     * to the view hierarchy.
                     * The fix for that situation is to continue to remove
                     * the present views until the end of the created view will match
                     * a beginning of a present view.
                     */
                    if (index + removeLength >= viewCount) {
                        // Should not happen but can't remove past the last view
                        break;
                    }
                    endOffset = getView(index + removeLength).getEndOffset();
                    removeLength++;
                    if (LOG.isLoggable(Level.FINE)) {
                        LOG.fine(
                            "GapBoxView.customReloadChildren(): Increased removeLength to "  // NOI18N
                            + removeLength + ", eo=" + endOffset // NOI18N
                        );
                    }
                }

                Element childElem = elem.getElement(elementIndex);
                while (childElem.getEndOffset() <= childViewEndOffset) {
                    elementIndex++;
                    if (elementIndex == elementCount) {
                        // #115034
                        break loop;
                    }
                    childElem = elem.getElement(elementIndex);
                }

                startOffset = childViewEndOffset;
            }

            added = new View[childViews.size()];
            childViews.toArray(added);
        }

        replace(index, removeLength, added);
    }
 

/**
 * Extend rectangular selection either by char in a specified selection
 * or by word (if ctrl is pressed).
 *
 * @param toRight true for right or false for left.
 * @param ctrl 
 */
public void extendRectangularSelection(boolean toRight, boolean ctrl) {
    JTextComponent c = component;
    Document doc = c.getDocument();
    int dotOffset = getDot();
    Element lineRoot = doc.getDefaultRootElement();
    int lineIndex = lineRoot.getElementIndex(dotOffset);
    Element lineElement = lineRoot.getElement(lineIndex);
    float charWidth;
    LockedViewHierarchy lvh = ViewHierarchy.get(c).lock();
    try {
        charWidth = lvh.getDefaultCharWidth();
    } finally {
        lvh.unlock();
    }
    int newDotOffset = -1;
    try {
        int newlineOffset = lineElement.getEndOffset() - 1;
        Rectangle newlineRect = c.modelToView(newlineOffset);
        if (!ctrl) {
            if (toRight) {
                if (rsDotRect.x < newlineRect.x) {
                    newDotOffset = dotOffset + 1;
                } else {
                    rsDotRect.x += charWidth;
                }
            } else { // toLeft
                if (rsDotRect.x > newlineRect.x) {
                    rsDotRect.x -= charWidth;
                    if (rsDotRect.x < newlineRect.x) { // Fix on rsDotRect
                        newDotOffset = newlineOffset;
                    }
                } else {
                    newDotOffset = Math.max(dotOffset - 1, lineElement.getStartOffset());
                }
            }

        } else { // With Ctrl
            int numVirtualChars = 8; // Number of virtual characters per one Ctrl+Shift+Arrow press
            if (toRight) {
                if (rsDotRect.x < newlineRect.x) {
                    newDotOffset = Math.min(Utilities.getNextWord(c, dotOffset), lineElement.getEndOffset() - 1);
                } else { // Extend virtually
                    rsDotRect.x += numVirtualChars * charWidth;
                }
            } else { // toLeft
                if (rsDotRect.x > newlineRect.x) { // Virtually extended
                    rsDotRect.x -= numVirtualChars * charWidth;
                    if (rsDotRect.x < newlineRect.x) {
                        newDotOffset = newlineOffset;
                    }
                } else {
                    newDotOffset = Math.max(Utilities.getPreviousWord(c, dotOffset), lineElement.getStartOffset());
                }
            }
        }

        if (newDotOffset != -1) {
            rsDotRect = c.modelToView(newDotOffset);
            moveDot(newDotOffset); // updates rs and fires state change
        } else {
            updateRectangularSelectionPaintRect();
            fireStateChanged();
        }
    } catch (BadLocationException ex) {
        // Leave selection as is
    }
}
 

/** 
 * Return line index (line number - 1) for some offset in document.
 * 
 * @param doc document to operate on.
 * @param offset offset in document.
 * @return line index >=0 since document always contains at least single '\n'.
 *  Returns 0 if offset <=0. Returns last line index if offset is beyond document's end.
 */
public static int getLineIndex(Document doc, int offset) {
    Element lineRoot = doc.getDefaultRootElement();
    return lineRoot.getElementIndex(offset);
}
 

/**
 * Return line index (line number - 1) for the given offset in the document.
 *
 * @param doc document to operate on
 * @param offset position in document where to start searching
 */
public static int getLineIndex(@NonNull LineDocument doc, int offset) throws BadLocationException {
    checkOffsetValid(doc, offset);
    Element lineRoot = doc.getParagraphElement(0).getParentElement();
    return lineRoot.getElementIndex(offset);
}