more.html

JSP中文介绍,对于菜鸟有用

    graphics2D.draw(carets[1]);
  }
}

private class HitTestMouseListener 
    extends MouseAdapter {
  public void mouseClicked(MouseEvent e) {
    Point2D origin = computeLayoutOrigin();
    float clickX = (float) (e.getX() - origin.getX());
    float clickY = (float) (e.getY() - origin.getY());

    TextHitInfo currentHit = 
      textLayout.hitTestChar(clickX, 
      insertionIndex = currentHit.getInsertionIndex();
    repaint();
  }
}

</PRE>

<A NAME=HIGHLIGHT></A>
<H3>Selection Highlighting</H3>

A <CODE>TextLayout</CODE> object supports highlighting the
entire length or portion of a text string on the screen. In this
example, the text string draws with caret at the
beginning of the line. The end user can drag the mouse from
there or click somewhere else and drag to highlight the characters. 
The 
code uses the<CODE>TextLayout.hitTestChar.</CODE> and
<CODE>TextLayout.getLogicalHighlightShape</CODE> to compute the 
endpoint and get a <CODE>Shape</CODE> that 
represents the highlight region.

<P>
Here is the complete 
<A HREF="./Code/SelectionSample.java">SelectionSample.java</A> 
source code.

<P>
<CENTER>
<IMG SRC="./Art/Selection.gif">
</CENTER>

<PRE>
public void paint(Graphics g) {
  Graphics2D graphics2D = (Graphics2D) g;
  Point2D origin = computeLayoutOrigin();
  graphics2D.translate(origin.getX(), origin.getY());
  boolean haveCaret = anchorEnd == activeEnd;

  if (!haveCaret) {
    Shape highlight = 
      textLayout.getLogicalHighlightShape(
      anchorEnd, activeEnd);
    graphics2D.setColor(HIGHLIGHT_COLOR);
    graphics2D.fill(highlight);
  }

  graphics2D.setColor(TEXT_COLOR);
  extLayout.draw(graphics2D, 0, 0);

  if (haveCaret) {
    Shape[] carets = 
      textLayout.getCaretShapes(anchorEnd);
    graphics2D.setColor(STRONG_CARET_COLOR);
    graphics2D.draw(carets[0]);

    if (carets[1] != null) {
      graphics2D.setColor(WEAK_CARET_COLOR);
      graphics2D.draw(carets[1]);
    }
  } 
}
private class SelectionMouseMotionListener 
    extends MouseMotionAdapter {
  public void mouseDragged(MouseEvent e) {
    Point2D origin = computeLayoutOrigin();

    float clickX = (float) (e.getX() - origin.getX());
    float clickY = (float) (e.getY() - origin.getY());
    TextHitInfo position = 
      textLayout.hitTestChar(clickX, clickY);
    int newActiveEnd = position.getInsertionIndex();

    if (activeEnd != newActiveEnd) {
      activeEnd = newActiveEnd;
      repaint();
    }
  }
}

private class SelectionMouseListener 
    extends MouseAdapter {
  public void mousePressed(MouseEvent e) {
    Point2D origin = computeLayoutOrigin();
    float clickX = (float) (e.getX() - origin.getX());
    float clickY = (float) (e.getY() - origin.getY());
    TextHitInfo position = 
      textLayout.hitTestChar(clickX, clickY);
    anchorEnd = position.getInsertionIndex();
    activeEnd = anchorEnd;
    repaint();
  }
}
</PRE>
	
<A NAME=CARET></A>
<H3>Moving the Caret</H3>

A <CODE>TextLayout</CODE> object supports moving through the
text string on the display one character at a time when the
end user presses the left and right arrow keys. In this next
example, an insertion offset is initially set to 0 and moved
by calling <CODE>TextLayout.getNextRightHit</CODE> and 
<CODE>TextLayout.getNextLeftHit</CODE> as appropriate in response
to left and right arrow key presses.

<P>
Here is the complete 
<A HREF="./Code/ArrowKeySample.java">ArrowKeySample.java</A> source code.

<P>
<CENTER>
<IMG SRC="./Art/Arrow.gif">
</CENTER>

<PRE>
public void paint(Graphics g) {
  Graphics2D graphics2D = (Graphics2D) g;
  Point2D origin = computeLayoutOrigin();
  graphics2D.translate(origin.getX(), origin.getY());

  textLayout.draw(graphics2D, 0, 0);
  Shape[] carets = 
    textLayout.getCaretShapes(insertionIndex);
  graphics2D.setColor(STRONG_CARET_COLOR);
  graphics2D.draw(carets[0]);

  if (carets[1] != null) {
    graphics2D.setColor(WEAK_CARET_COLOR);
    graphics2D.draw(carets[1]);
  }
 }

 private class ArrowKeyListener extends KeyAdapter {
   private void handleArrowKey(boolean rightArrow) {
     TextHitInfo newPosition;

     if (rightArrow) {
       newPosition = 
         textLayout.getNextRightHit(insertionIndex);
     }
     else {
       newPosition = 
         textLayout.getNextLeftHit(insertionIndex);
     }

    if (newPosition != null) {
      insertionIndex = newPosition.getInsertionIndex();
      repaint();
    }
  }
  public void keyPressed(KeyEvent e) {
    int keyCode = e.getKeyCode();

    if (keyCode == KeyEvent.VK_LEFT ||
                   keyCode == KeyEvent.VK_RIGHT) {
      handleArrowKey(keyCode == KeyEvent.VK_RIGHT);
    }
  }
</PRE>

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