The Java Tutorials have been written for JDK 8. Examples and practices described in this page don't take advantage of improvements introduced in later releases and might use technology no longer available.
See Java Language Changes for a summary of updated language features in Java SE 9 and subsequent releases.
See JDK Release Notes for information about new features, enhancements, and removed or deprecated options for all JDK releases.
Any
Shape
object can be used as a clipping path that restricts the portion of the drawing area that will be rendered. The clipping path is part of the
Graphics2D
context; to set the clip attribute, you call Graphics2D.setClip
and pass in the Shape
that defines the clipping path you want to use. You can shrink the clipping path by calling the clip
method and passing in another Shape
; the clip is set to the intersection of the current clip and the specified Shape
.
This example animates a clipping path to reveal different portions of an image.
ClipImage.java
contains the complete code for this applet. The applet requires the clouds.jpg
image file.
The clipping path is defined by the intersection of an ellipse and a rectangle whose dimensions are set randomly. The ellipse is passed to the setClip
method, and then clip
is called to set the clipping path to the intersection of the ellipse and the rectangle.
private Ellipse2D ellipse = new Ellipse2D.Float(); private Rectangle2D rect = new Rectangle2D.Float(); ... ellipse.setFrame(x, y, ew, eh); g2.setClip(ellipse); rect.setRect(x+5, y+5, ew-10, eh-10); g2.clip(rect);
A clipping area can also be created from a text string. The following example creates a TextLayout
with the string The Starry Night. Then, it gets the outline of the TextLayout
. The
TextLayout.getOutline
method returns a Shape
object and a Rectangle
is created from the bounds of this Shape
object. The bounds contain all the pixels the layout can draw. The color in the graphics context is set to blue and the outline shape is drawn, as illustrated by the following image and code snippet.
FontRenderContext frc = g2.getFontRenderContext(); Font f = new Font("Helvetica", 1, w/10); String s = new String("The Starry Night"); TextLayout textTl = new TextLayout(s, f, frc); AffineTransform transform = new AffineTransform(); Shape outline = textTl.getOutline(null); Rectangle r = outline.getBounds(); transform = g2.getTransform(); transform.translate(w/2-(r.width/2), h/2+(r.height/2)); g2.transform(transform); g2.setColor(Color.blue); g2.draw(outline);
Next, a clipping area is set on the graphics context using the Shape
object created from getOutline
. The starry.gif
image, which is Van Gogh's famous painting, The Starry Night, is drawn into this clipping area starting at the lower left corner of the Rectangle
object.
g2.setClip(outline); g2.drawImage(img, r.x, r.y, r.width, r.height, this);
Starry.java
contains the complete code for this program. This applet requires the Starry.gif
image file.