| /* |
| * Copyright (c) 1997, 2008, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package javax.swing; |
| |
| import java.awt.*; |
| import java.awt.event.*; |
| import java.awt.image.VolatileImage; |
| import java.awt.peer.ComponentPeer; |
| import java.applet.Applet; |
| import java.beans.Transient; |
| import javax.swing.plaf.ViewportUI; |
| |
| import javax.swing.event.*; |
| import javax.swing.border.*; |
| import javax.accessibility.*; |
| |
| |
| import java.io.Serializable; |
| |
| |
| /** |
| * The "viewport" or "porthole" through which you see the underlying |
| * information. When you scroll, what moves is the viewport. It is like |
| * peering through a camera's viewfinder. Moving the viewfinder upwards |
| * brings new things into view at the top of the picture and loses |
| * things that were at the bottom. |
| * <p> |
| * By default, <code>JViewport</code> is opaque. To change this, use the |
| * <code>setOpaque</code> method. |
| * <p> |
| * <b>NOTE:</b>We have implemented a faster scrolling algorithm that |
| * does not require a buffer to draw in. The algorithm works as follows: |
| * <ol><li>The view and parent view and checked to see if they are |
| * <code>JComponents</code>, |
| * if they aren't, stop and repaint the whole viewport. |
| * <li>If the viewport is obscured by an ancestor, stop and repaint the whole |
| * viewport. |
| * <li>Compute the region that will become visible, if it is as big as |
| * the viewport, stop and repaint the whole view region. |
| * <li>Obtain the ancestor <code>Window</code>'s graphics and |
| * do a <code>copyArea</code> on the scrolled region. |
| * <li>Message the view to repaint the newly visible region. |
| * <li>The next time paint is invoked on the viewport, if the clip region |
| * is smaller than the viewport size a timer is kicked off to repaint the |
| * whole region. |
| * </ol> |
| * In general this approach is much faster. Compared to the backing store |
| * approach this avoids the overhead of maintaining an offscreen buffer and |
| * having to do two <code>copyArea</code>s. |
| * Compared to the non backing store case this |
| * approach will greatly reduce the painted region. |
| * <p> |
| * This approach can cause slower times than the backing store approach |
| * when the viewport is obscured by another window, or partially offscreen. |
| * When another window |
| * obscures the viewport the copyArea will copy garbage and a |
| * paint event will be generated by the system to inform us we need to |
| * paint the newly exposed region. The only way to handle this is to |
| * repaint the whole viewport, which can cause slower performance than the |
| * backing store case. In most applications very rarely will the user be |
| * scrolling while the viewport is obscured by another window or offscreen, |
| * so this optimization is usually worth the performance hit when obscured. |
| * <p> |
| * <strong>Warning:</strong> Swing is not thread safe. For more |
| * information see <a |
| * href="package-summary.html#threading">Swing's Threading |
| * Policy</a>. |
| * <p> |
| * <strong>Warning:</strong> |
| * Serialized objects of this class will not be compatible with |
| * future Swing releases. The current serialization support is |
| * appropriate for short term storage or RMI between applications running |
| * the same version of Swing. As of 1.4, support for long term storage |
| * of all JavaBeans<sup><font size="-2">TM</font></sup> |
| * has been added to the <code>java.beans</code> package. |
| * Please see {@link java.beans.XMLEncoder}. |
| * |
| * @author Hans Muller |
| * @author Philip Milne |
| * @see JScrollPane |
| */ |
| public class JViewport extends JComponent implements Accessible |
| { |
| /** |
| * @see #getUIClassID |
| * @see #readObject |
| */ |
| private static final String uiClassID = "ViewportUI"; |
| |
| /** Property used to indicate window blitting should not be done. |
| */ |
| static final Object EnableWindowBlit = "EnableWindowBlit"; |
| |
| /** |
| * True when the viewport dimensions have been determined. |
| * The default is false. |
| */ |
| protected boolean isViewSizeSet = false; |
| |
| /** |
| * The last <code>viewPosition</code> that we've painted, so we know how |
| * much of the backing store image is valid. |
| */ |
| protected Point lastPaintPosition = null; |
| |
| /** |
| * True when this viewport is maintaining an offscreen image of its |
| * contents, so that some scrolling can take place using fast "bit-blit" |
| * operations instead of by accessing the view object to construct the |
| * display. The default is <code>false</code>. |
| * |
| * @deprecated As of Java 2 platform v1.3 |
| * @see #setScrollMode |
| */ |
| @Deprecated |
| protected boolean backingStore = false; |
| |
| /** The view image used for a backing store. */ |
| transient protected Image backingStoreImage = null; |
| |
| /** |
| * The <code>scrollUnderway</code> flag is used for components like |
| * <code>JList</code>. When the downarrow key is pressed on a |
| * <code>JList</code> and the selected |
| * cell is the last in the list, the <code>scrollpane</code> autoscrolls. |
| * Here, the old selected cell needs repainting and so we need |
| * a flag to make the viewport do the optimized painting |
| * only when there is an explicit call to |
| * <code>setViewPosition(Point)</code>. |
| * When <code>setBounds</code> is called through other routes, |
| * the flag is off and the view repaints normally. Another approach |
| * would be to remove this from the <code>JViewport</code> |
| * class and have the <code>JList</code> manage this case by using |
| * <code>setBackingStoreEnabled</code>. The default is |
| * <code>false</code>. |
| */ |
| protected boolean scrollUnderway = false; |
| |
| /* |
| * Listener that is notified each time the view changes size. |
| */ |
| private ComponentListener viewListener = null; |
| |
| /* Only one <code>ChangeEvent</code> is needed per |
| * <code>JViewport</code> instance since the |
| * event's only (read-only) state is the source property. The source |
| * of events generated here is always "this". |
| */ |
| private transient ChangeEvent changeEvent = null; |
| |
| /** |
| * Use <code>graphics.copyArea</code> to implement scrolling. |
| * This is the fastest for most applications. |
| * |
| * @see #setScrollMode |
| * @since 1.3 |
| */ |
| public static final int BLIT_SCROLL_MODE = 1; |
| |
| /** |
| * Draws viewport contents into an offscreen image. |
| * This was previously the default mode for <code>JTable</code>. |
| * This mode may offer advantages over "blit mode" |
| * in some cases, but it requires a large chunk of extra RAM. |
| * |
| * @see #setScrollMode |
| * @since 1.3 |
| */ |
| public static final int BACKINGSTORE_SCROLL_MODE = 2; |
| |
| /** |
| * This mode uses the very simple method of redrawing the entire |
| * contents of the scrollpane each time it is scrolled. |
| * This was the default behavior in Swing 1.0 and Swing 1.1. |
| * Either of the other two options will provide better performance |
| * in most cases. |
| * |
| * @see #setScrollMode |
| * @since 1.3 |
| */ |
| public static final int SIMPLE_SCROLL_MODE = 0; |
| |
| /** |
| * @see #setScrollMode |
| * @since 1.3 |
| */ |
| private int scrollMode = BLIT_SCROLL_MODE; |
| |
| // |
| // Window blitting: |
| // |
| // As mentioned in the javadoc when using windowBlit a paint event |
| // will be generated by the system if copyArea copies a non-visible |
| // portion of the view (in other words, it copies garbage). We are |
| // not guaranteed to receive the paint event before other mouse events, |
| // so we can not be sure we haven't already copied garbage a bunch of |
| // times to different parts of the view. For that reason when a blit |
| // happens and the Component is obscured (the check for obscurity |
| // is not supported on all platforms and is checked via ComponentPeer |
| // methods) the ivar repaintAll is set to true. When paint is received |
| // if repaintAll is true (we previously did a blit) it is set to |
| // false, and if the clip region is smaller than the viewport |
| // waitingForRepaint is set to true and a timer is started. When |
| // the timer fires if waitingForRepaint is true, repaint is invoked. |
| // In the mean time, if the view is asked to scroll and waitingForRepaint |
| // is true, a blit will not happen, instead the non-backing store case |
| // of scrolling will happen, which will reset waitingForRepaint. |
| // waitingForRepaint is set to false in paint when the clip rect is |
| // bigger (or equal) to the size of the viewport. |
| // A Timer is used instead of just a repaint as it appeared to offer |
| // better performance. |
| |
| |
| /** |
| * This is set to true in <code>setViewPosition</code> |
| * if doing a window blit and the viewport is obscured. |
| */ |
| private transient boolean repaintAll; |
| |
| /** |
| * This is set to true in paint, if <code>repaintAll</code> |
| * is true and the clip rectangle does not match the bounds. |
| * If true, and scrolling happens the |
| * repaint manager is not cleared which then allows for the repaint |
| * previously invoked to succeed. |
| */ |
| private transient boolean waitingForRepaint; |
| |
| /** |
| * Instead of directly invoking repaint, a <code>Timer</code> |
| * is started and when it fires, repaint is invoked. |
| */ |
| private transient Timer repaintTimer; |
| |
| /** |
| * Set to true in paintView when paint is invoked. |
| */ |
| private transient boolean inBlitPaint; |
| |
| /** |
| * Whether or not a valid view has been installed. |
| */ |
| private boolean hasHadValidView; |
| |
| /** Creates a <code>JViewport</code>. */ |
| public JViewport() { |
| super(); |
| setLayout(createLayoutManager()); |
| setOpaque(true); |
| updateUI(); |
| setInheritsPopupMenu(true); |
| } |
| |
| |
| |
| /** |
| * Returns the L&F object that renders this component. |
| * |
| * @return a <code>ViewportUI</code> object |
| * @since 1.3 |
| */ |
| public ViewportUI getUI() { |
| return (ViewportUI)ui; |
| } |
| |
| |
| /** |
| * Sets the L&F object that renders this component. |
| * |
| * @param ui the <code>ViewportUI</code> L&F object |
| * @see UIDefaults#getUI |
| * @beaninfo |
| * bound: true |
| * hidden: true |
| * attribute: visualUpdate true |
| * description: The UI object that implements the Component's LookAndFeel. |
| * @since 1.3 |
| */ |
| public void setUI(ViewportUI ui) { |
| super.setUI(ui); |
| } |
| |
| |
| /** |
| * Resets the UI property to a value from the current look and feel. |
| * |
| * @see JComponent#updateUI |
| */ |
| public void updateUI() { |
| setUI((ViewportUI)UIManager.getUI(this)); |
| } |
| |
| |
| /** |
| * Returns a string that specifies the name of the L&F class |
| * that renders this component. |
| * |
| * @return the string "ViewportUI" |
| * |
| * @see JComponent#getUIClassID |
| * @see UIDefaults#getUI |
| */ |
| public String getUIClassID() { |
| return uiClassID; |
| } |
| |
| |
| /** |
| * Sets the <code>JViewport</code>'s one lightweight child, |
| * which can be <code>null</code>. |
| * (Since there is only one child which occupies the entire viewport, |
| * the <code>constraints</code> and <code>index</code> |
| * arguments are ignored.) |
| * |
| * @param child the lightweight <code>child</code> of the viewport |
| * @param constraints the <code>constraints</code> to be respected |
| * @param index the index |
| * @see #setView |
| */ |
| protected void addImpl(Component child, Object constraints, int index) { |
| setView(child); |
| } |
| |
| |
| /** |
| * Removes the <code>Viewport</code>s one lightweight child. |
| * |
| * @see #setView |
| */ |
| public void remove(Component child) { |
| child.removeComponentListener(viewListener); |
| super.remove(child); |
| } |
| |
| |
| /** |
| * Scrolls the view so that <code>Rectangle</code> |
| * within the view becomes visible. |
| * <p> |
| * This attempts to validate the view before scrolling if the |
| * view is currently not valid - <code>isValid</code> returns false. |
| * To avoid excessive validation when the containment hierarchy is |
| * being created this will not validate if one of the ancestors does not |
| * have a peer, or there is no validate root ancestor, or one of the |
| * ancestors is not a <code>Window</code> or <code>Applet</code>. |
| * <p> |
| * Note that this method will not scroll outside of the |
| * valid viewport; for example, if <code>contentRect</code> is larger |
| * than the viewport, scrolling will be confined to the viewport's |
| * bounds. |
| * |
| * @param contentRect the <code>Rectangle</code> to display |
| * @see JComponent#isValidateRoot |
| * @see java.awt.Component#isValid |
| * @see java.awt.Component#getPeer |
| */ |
| public void scrollRectToVisible(Rectangle contentRect) { |
| Component view = getView(); |
| |
| if (view == null) { |
| return; |
| } else { |
| if (!view.isValid()) { |
| // If the view is not valid, validate. scrollRectToVisible |
| // may fail if the view is not valid first, contentRect |
| // could be bigger than invalid size. |
| validateView(); |
| } |
| int dx, dy; |
| |
| dx = positionAdjustment(getWidth(), contentRect.width, contentRect.x); |
| dy = positionAdjustment(getHeight(), contentRect.height, contentRect.y); |
| |
| if (dx != 0 || dy != 0) { |
| Point viewPosition = getViewPosition(); |
| Dimension viewSize = view.getSize(); |
| int startX = viewPosition.x; |
| int startY = viewPosition.y; |
| Dimension extent = getExtentSize(); |
| |
| viewPosition.x -= dx; |
| viewPosition.y -= dy; |
| // Only constrain the location if the view is valid. If the |
| // the view isn't valid, it typically indicates the view |
| // isn't visible yet and most likely has a bogus size as will |
| // we, and therefore we shouldn't constrain the scrolling |
| if (view.isValid()) { |
| if (getParent().getComponentOrientation().isLeftToRight()) { |
| if (viewPosition.x + extent.width > viewSize.width) { |
| viewPosition.x = Math.max(0, viewSize.width - extent.width); |
| } else if (viewPosition.x < 0) { |
| viewPosition.x = 0; |
| } |
| } else { |
| if (extent.width > viewSize.width) { |
| viewPosition.x = viewSize.width - extent.width; |
| } else { |
| viewPosition.x = Math.max(0, Math.min(viewSize.width - extent.width, viewPosition.x)); |
| } |
| } |
| if (viewPosition.y + extent.height > viewSize.height) { |
| viewPosition.y = Math.max(0, viewSize.height - |
| extent.height); |
| } |
| else if (viewPosition.y < 0) { |
| viewPosition.y = 0; |
| } |
| } |
| if (viewPosition.x != startX || viewPosition.y != startY) { |
| setViewPosition(viewPosition); |
| // NOTE: How JViewport currently works with the |
| // backing store is not foolproof. The sequence of |
| // events when setViewPosition |
| // (scrollRectToVisible) is called is to reset the |
| // views bounds, which causes a repaint on the |
| // visible region and sets an ivar indicating |
| // scrolling (scrollUnderway). When |
| // JViewport.paint is invoked if scrollUnderway is |
| // true, the backing store is blitted. This fails |
| // if between the time setViewPosition is invoked |
| // and paint is received another repaint is queued |
| // indicating part of the view is invalid. There |
| // is no way for JViewport to notice another |
| // repaint has occured and it ends up blitting |
| // what is now a dirty region and the repaint is |
| // never delivered. |
| // It just so happens JTable encounters this |
| // behavior by way of scrollRectToVisible, for |
| // this reason scrollUnderway is set to false |
| // here, which effectively disables the backing |
| // store. |
| scrollUnderway = false; |
| } |
| } |
| } |
| } |
| |
| /** |
| * Ascends the <code>Viewport</code>'s parents stopping when |
| * a component is found that returns |
| * <code>true</code> to <code>isValidateRoot</code>. |
| * If all the <code>Component</code>'s parents are visible, |
| * <code>validate</code> will then be invoked on it. The |
| * <code>RepaintManager</code> is then invoked with |
| * <code>removeInvalidComponent</code>. This |
| * is the synchronous version of a <code>revalidate</code>. |
| */ |
| private void validateView() { |
| Component validateRoot = SwingUtilities.getValidateRoot(this, false); |
| |
| if (validateRoot == null) { |
| return; |
| } |
| |
| // Validate the root. |
| validateRoot.validate(); |
| |
| // And let the RepaintManager it does not have to validate from |
| // validateRoot anymore. |
| RepaintManager rm = RepaintManager.currentManager(this); |
| |
| if (rm != null) { |
| rm.removeInvalidComponent((JComponent)validateRoot); |
| } |
| } |
| |
| /* Used by the scrollRectToVisible method to determine the |
| * proper direction and amount to move by. The integer variables are named |
| * width, but this method is applicable to height also. The code assumes that |
| * parentWidth/childWidth are positive and childAt can be negative. |
| */ |
| private int positionAdjustment(int parentWidth, int childWidth, int childAt) { |
| |
| // +-----+ |
| // | --- | No Change |
| // +-----+ |
| if (childAt >= 0 && childWidth + childAt <= parentWidth) { |
| return 0; |
| } |
| |
| // +-----+ |
| // --------- No Change |
| // +-----+ |
| if (childAt <= 0 && childWidth + childAt >= parentWidth) { |
| return 0; |
| } |
| |
| // +-----+ +-----+ |
| // | ---- -> | ----| |
| // +-----+ +-----+ |
| if (childAt > 0 && childWidth <= parentWidth) { |
| return -childAt + parentWidth - childWidth; |
| } |
| |
| // +-----+ +-----+ |
| // | -------- -> |-------- |
| // +-----+ +-----+ |
| if (childAt >= 0 && childWidth >= parentWidth) { |
| return -childAt; |
| } |
| |
| // +-----+ +-----+ |
| // ---- | -> |---- | |
| // +-----+ +-----+ |
| if (childAt <= 0 && childWidth <= parentWidth) { |
| return -childAt; |
| } |
| |
| // +-----+ +-----+ |
| //-------- | -> --------| |
| // +-----+ +-----+ |
| if (childAt < 0 && childWidth >= parentWidth) { |
| return -childAt + parentWidth - childWidth; |
| } |
| |
| return 0; |
| } |
| |
| |
| /** |
| * The viewport "scrolls" its child (called the "view") by the |
| * normal parent/child clipping (typically the view is moved in |
| * the opposite direction of the scroll). A non-<code>null</code> border, |
| * or non-zero insets, isn't supported, to prevent the geometry |
| * of this component from becoming complex enough to inhibit |
| * subclassing. To create a <code>JViewport</code> with a border, |
| * add it to a <code>JPanel</code> that has a border. |
| * <p>Note: If <code>border</code> is non-<code>null</code>, this |
| * method will throw an exception as borders are not supported on |
| * a <code>JViewPort</code>. |
| * |
| * @param border the <code>Border</code> to set |
| * @exception IllegalArgumentException this method is not implemented |
| */ |
| public final void setBorder(Border border) { |
| if (border != null) { |
| throw new IllegalArgumentException("JViewport.setBorder() not supported"); |
| } |
| } |
| |
| |
| /** |
| * Returns the insets (border) dimensions as (0,0,0,0), since borders |
| * are not supported on a <code>JViewport</code>. |
| * |
| * @return a <code>Rectange</code> of zero dimension and zero origin |
| * @see #setBorder |
| */ |
| public final Insets getInsets() { |
| return new Insets(0, 0, 0, 0); |
| } |
| |
| /** |
| * Returns an <code>Insets</code> object containing this |
| * <code>JViewport</code>s inset values. The passed-in |
| * <code>Insets</code> object will be reinitialized, and |
| * all existing values within this object are overwritten. |
| * |
| * @param insets the <code>Insets</code> object which can be reused |
| * @return this viewports inset values |
| * @see #getInsets |
| * @beaninfo |
| * expert: true |
| */ |
| public final Insets getInsets(Insets insets) { |
| insets.left = insets.top = insets.right = insets.bottom = 0; |
| return insets; |
| } |
| |
| |
| private Graphics getBackingStoreGraphics(Graphics g) { |
| Graphics bsg = backingStoreImage.getGraphics(); |
| bsg.setColor(g.getColor()); |
| bsg.setFont(g.getFont()); |
| bsg.setClip(g.getClipBounds()); |
| return bsg; |
| } |
| |
| |
| private void paintViaBackingStore(Graphics g) { |
| Graphics bsg = getBackingStoreGraphics(g); |
| try { |
| super.paint(bsg); |
| g.drawImage(backingStoreImage, 0, 0, this); |
| } finally { |
| bsg.dispose(); |
| } |
| } |
| |
| private void paintViaBackingStore(Graphics g, Rectangle oClip) { |
| Graphics bsg = getBackingStoreGraphics(g); |
| try { |
| super.paint(bsg); |
| g.setClip(oClip); |
| g.drawImage(backingStoreImage, 0, 0, this); |
| } finally { |
| bsg.dispose(); |
| } |
| } |
| |
| /** |
| * The <code>JViewport</code> overrides the default implementation of |
| * this method (in <code>JComponent</code>) to return false. |
| * This ensures |
| * that the drawing machinery will call the <code>Viewport</code>'s |
| * <code>paint</code> |
| * implementation rather than messaging the <code>JViewport</code>'s |
| * children directly. |
| * |
| * @return false |
| */ |
| public boolean isOptimizedDrawingEnabled() { |
| return false; |
| } |
| |
| /** |
| * Returns true if scroll mode is a BACKINGSTORE_SCROLL_MODE to cause |
| * painting to originate from <code>JViewport</code>, or one of its |
| * ancestors. Otherwise returns false. |
| * |
| * @return true if if scroll mode is a BACKINGSTORE_SCROLL_MODE. |
| * @see JComponent#isPaintingOrigin() |
| */ |
| boolean isPaintingOrigin() { |
| return scrollMode == BACKINGSTORE_SCROLL_MODE; |
| } |
| |
| |
| /** |
| * Only used by the paint method below. |
| */ |
| private Point getViewLocation() { |
| Component view = getView(); |
| if (view != null) { |
| return view.getLocation(); |
| } |
| else { |
| return new Point(0,0); |
| } |
| } |
| |
| /** |
| * Depending on whether the <code>backingStore</code> is enabled, |
| * either paint the image through the backing store or paint |
| * just the recently exposed part, using the backing store |
| * to "blit" the remainder. |
| * <blockquote> |
| * The term "blit" is the pronounced version of the PDP-10 |
| * BLT (BLock Transfer) instruction, which copied a block of |
| * bits. (In case you were curious.) |
| * </blockquote> |
| * |
| * @param g the <code>Graphics</code> context within which to paint |
| */ |
| public void paint(Graphics g) |
| { |
| int width = getWidth(); |
| int height = getHeight(); |
| |
| if ((width <= 0) || (height <= 0)) { |
| return; |
| } |
| |
| if (inBlitPaint) { |
| // We invoked paint as part of copyArea cleanup, let it through. |
| super.paint(g); |
| return; |
| } |
| |
| if (repaintAll) { |
| repaintAll = false; |
| Rectangle clipB = g.getClipBounds(); |
| if (clipB.width < getWidth() || |
| clipB.height < getHeight()) { |
| waitingForRepaint = true; |
| if (repaintTimer == null) { |
| repaintTimer = createRepaintTimer(); |
| } |
| repaintTimer.stop(); |
| repaintTimer.start(); |
| // We really don't need to paint, a future repaint will |
| // take care of it, but if we don't we get an ugly flicker. |
| } |
| else { |
| if (repaintTimer != null) { |
| repaintTimer.stop(); |
| } |
| waitingForRepaint = false; |
| } |
| } |
| else if (waitingForRepaint) { |
| // Need a complete repaint before resetting waitingForRepaint |
| Rectangle clipB = g.getClipBounds(); |
| if (clipB.width >= getWidth() && |
| clipB.height >= getHeight()) { |
| waitingForRepaint = false; |
| repaintTimer.stop(); |
| } |
| } |
| |
| if (!backingStore || isBlitting() || getView() == null) { |
| super.paint(g); |
| lastPaintPosition = getViewLocation(); |
| return; |
| } |
| |
| // If the view is smaller than the viewport and we are not opaque |
| // (that is, we won't paint our background), we should set the |
| // clip. Otherwise, as the bounds of the view vary, we will |
| // blit garbage into the exposed areas. |
| Rectangle viewBounds = getView().getBounds(); |
| if (!isOpaque()) { |
| g.clipRect(0, 0, viewBounds.width, viewBounds.height); |
| } |
| |
| if (backingStoreImage == null) { |
| // Backing store is enabled but this is the first call to paint. |
| // Create the backing store, paint it and then copy to g. |
| // The backing store image will be created with the size of |
| // the viewport. We must make sure the clip region is the |
| // same size, otherwise when scrolling the backing image |
| // the region outside of the clipped region will not be painted, |
| // and result in empty areas. |
| backingStoreImage = createImage(width, height); |
| Rectangle clip = g.getClipBounds(); |
| if (clip.width != width || clip.height != height) { |
| if (!isOpaque()) { |
| g.setClip(0, 0, Math.min(viewBounds.width, width), |
| Math.min(viewBounds.height, height)); |
| } |
| else { |
| g.setClip(0, 0, width, height); |
| } |
| paintViaBackingStore(g, clip); |
| } |
| else { |
| paintViaBackingStore(g); |
| } |
| } |
| else { |
| if (!scrollUnderway || lastPaintPosition.equals(getViewLocation())) { |
| // No scrolling happened: repaint required area via backing store. |
| paintViaBackingStore(g); |
| } else { |
| // The image was scrolled. Manipulate the backing store and flush it to g. |
| Point blitFrom = new Point(); |
| Point blitTo = new Point(); |
| Dimension blitSize = new Dimension(); |
| Rectangle blitPaint = new Rectangle(); |
| |
| Point newLocation = getViewLocation(); |
| int dx = newLocation.x - lastPaintPosition.x; |
| int dy = newLocation.y - lastPaintPosition.y; |
| boolean canBlit = computeBlit(dx, dy, blitFrom, blitTo, blitSize, blitPaint); |
| if (!canBlit) { |
| // The image was either moved diagonally or |
| // moved by more than the image size: paint normally. |
| paintViaBackingStore(g); |
| } else { |
| int bdx = blitTo.x - blitFrom.x; |
| int bdy = blitTo.y - blitFrom.y; |
| |
| // Move the relevant part of the backing store. |
| Rectangle clip = g.getClipBounds(); |
| // We don't want to inherit the clip region when copying |
| // bits, if it is inherited it will result in not moving |
| // all of the image resulting in garbage appearing on |
| // the screen. |
| g.setClip(0, 0, width, height); |
| Graphics bsg = getBackingStoreGraphics(g); |
| try { |
| bsg.copyArea(blitFrom.x, blitFrom.y, blitSize.width, blitSize.height, bdx, bdy); |
| |
| g.setClip(clip.x, clip.y, clip.width, clip.height); |
| // Paint the rest of the view; the part that has just been exposed. |
| Rectangle r = viewBounds.intersection(blitPaint); |
| bsg.setClip(r); |
| super.paint(bsg); |
| |
| // Copy whole of the backing store to g. |
| g.drawImage(backingStoreImage, 0, 0, this); |
| } finally { |
| bsg.dispose(); |
| } |
| } |
| } |
| } |
| lastPaintPosition = getViewLocation(); |
| scrollUnderway = false; |
| } |
| |
| |
| /** |
| * Sets the bounds of this viewport. If the viewport's width |
| * or height has changed, fire a <code>StateChanged</code> event. |
| * |
| * @param x left edge of the origin |
| * @param y top edge of the origin |
| * @param w width in pixels |
| * @param h height in pixels |
| * |
| * @see JComponent#reshape(int, int, int, int) |
| */ |
| public void reshape(int x, int y, int w, int h) { |
| boolean sizeChanged = (getWidth() != w) || (getHeight() != h); |
| if (sizeChanged) { |
| backingStoreImage = null; |
| } |
| super.reshape(x, y, w, h); |
| if (sizeChanged) { |
| fireStateChanged(); |
| } |
| } |
| |
| |
| /** |
| * Used to control the method of scrolling the viewport contents. |
| * You may want to change this mode to get maximum performance for your |
| * use case. |
| * |
| * @param mode one of the following values: |
| * <ul> |
| * <li> JViewport.BLIT_SCROLL_MODE |
| * <li> JViewport.BACKINGSTORE_SCROLL_MODE |
| * <li> JViewport.SIMPLE_SCROLL_MODE |
| * </ul> |
| * |
| * @see #BLIT_SCROLL_MODE |
| * @see #BACKINGSTORE_SCROLL_MODE |
| * @see #SIMPLE_SCROLL_MODE |
| * |
| * @beaninfo |
| * bound: false |
| * description: Method of moving contents for incremental scrolls. |
| * enum: BLIT_SCROLL_MODE JViewport.BLIT_SCROLL_MODE |
| * BACKINGSTORE_SCROLL_MODE JViewport.BACKINGSTORE_SCROLL_MODE |
| * SIMPLE_SCROLL_MODE JViewport.SIMPLE_SCROLL_MODE |
| * |
| * @since 1.3 |
| */ |
| public void setScrollMode(int mode) { |
| scrollMode = mode; |
| backingStore = mode == BACKINGSTORE_SCROLL_MODE; |
| } |
| |
| /** |
| * Returns the current scrolling mode. |
| * |
| * @return the <code>scrollMode</code> property |
| * @see #setScrollMode |
| * @since 1.3 |
| */ |
| public int getScrollMode() { |
| return scrollMode; |
| } |
| |
| /** |
| * Returns <code>true</code> if this viewport is maintaining |
| * an offscreen image of its contents. |
| * |
| * @return <code>true</code> if <code>scrollMode</code> is |
| * <code>BACKINGSTORE_SCROLL_MODE</code> |
| * |
| * @deprecated As of Java 2 platform v1.3, replaced by |
| * <code>getScrollMode()</code>. |
| */ |
| @Deprecated |
| public boolean isBackingStoreEnabled() { |
| return scrollMode == BACKINGSTORE_SCROLL_MODE; |
| } |
| |
| |
| /** |
| * If true if this viewport will maintain an offscreen |
| * image of its contents. The image is used to reduce the cost |
| * of small one dimensional changes to the <code>viewPosition</code>. |
| * Rather than repainting the entire viewport we use |
| * <code>Graphics.copyArea</code> to effect some of the scroll. |
| * |
| * @param enabled if true, maintain an offscreen backing store |
| * |
| * @deprecated As of Java 2 platform v1.3, replaced by |
| * <code>setScrollMode()</code>. |
| */ |
| @Deprecated |
| public void setBackingStoreEnabled(boolean enabled) { |
| if (enabled) { |
| setScrollMode(BACKINGSTORE_SCROLL_MODE); |
| } else { |
| setScrollMode(BLIT_SCROLL_MODE); |
| } |
| } |
| |
| private boolean isBlitting() { |
| Component view = getView(); |
| return (scrollMode == BLIT_SCROLL_MODE) && |
| (view instanceof JComponent) && view.isOpaque(); |
| } |
| |
| |
| /** |
| * Returns the <code>JViewport</code>'s one child or <code>null</code>. |
| * |
| * @return the viewports child, or <code>null</code> if none exists |
| * |
| * @see #setView |
| */ |
| public Component getView() { |
| return (getComponentCount() > 0) ? getComponent(0) : null; |
| } |
| |
| /** |
| * Sets the <code>JViewport</code>'s one lightweight child |
| * (<code>view</code>), which can be <code>null</code>. |
| * |
| * @param view the viewport's new lightweight child |
| * |
| * @see #getView |
| */ |
| public void setView(Component view) { |
| |
| /* Remove the viewport's existing children, if any. |
| * Note that removeAll() isn't used here because it |
| * doesn't call remove() (which JViewport overrides). |
| */ |
| int n = getComponentCount(); |
| for(int i = n - 1; i >= 0; i--) { |
| remove(getComponent(i)); |
| } |
| |
| isViewSizeSet = false; |
| |
| if (view != null) { |
| super.addImpl(view, null, -1); |
| viewListener = createViewListener(); |
| view.addComponentListener(viewListener); |
| } |
| |
| if (hasHadValidView) { |
| // Only fire a change if a view has been installed. |
| fireStateChanged(); |
| } |
| else if (view != null) { |
| hasHadValidView = true; |
| } |
| |
| revalidate(); |
| repaint(); |
| } |
| |
| |
| /** |
| * If the view's size hasn't been explicitly set, return the |
| * preferred size, otherwise return the view's current size. |
| * If there is no view, return 0,0. |
| * |
| * @return a <code>Dimension</code> object specifying the size of the view |
| */ |
| public Dimension getViewSize() { |
| Component view = getView(); |
| |
| if (view == null) { |
| return new Dimension(0,0); |
| } |
| else if (isViewSizeSet) { |
| return view.getSize(); |
| } |
| else { |
| return view.getPreferredSize(); |
| } |
| } |
| |
| |
| /** |
| * Sets the size of the view. A state changed event will be fired. |
| * |
| * @param newSize a <code>Dimension</code> object specifying the new |
| * size of the view |
| */ |
| public void setViewSize(Dimension newSize) { |
| Component view = getView(); |
| if (view != null) { |
| Dimension oldSize = view.getSize(); |
| if (!newSize.equals(oldSize)) { |
| // scrollUnderway will be true if this is invoked as the |
| // result of a validate and setViewPosition was previously |
| // invoked. |
| scrollUnderway = false; |
| view.setSize(newSize); |
| isViewSizeSet = true; |
| fireStateChanged(); |
| } |
| } |
| } |
| |
| /** |
| * Returns the view coordinates that appear in the upper left |
| * hand corner of the viewport, or 0,0 if there's no view. |
| * |
| * @return a <code>Point</code> object giving the upper left coordinates |
| */ |
| public Point getViewPosition() { |
| Component view = getView(); |
| if (view != null) { |
| Point p = view.getLocation(); |
| p.x = -p.x; |
| p.y = -p.y; |
| return p; |
| } |
| else { |
| return new Point(0,0); |
| } |
| } |
| |
| |
| /** |
| * Sets the view coordinates that appear in the upper left |
| * hand corner of the viewport, does nothing if there's no view. |
| * |
| * @param p a <code>Point</code> object giving the upper left coordinates |
| */ |
| public void setViewPosition(Point p) |
| { |
| Component view = getView(); |
| if (view == null) { |
| return; |
| } |
| |
| int oldX, oldY, x = p.x, y = p.y; |
| |
| /* Collect the old x,y values for the views location |
| * and do the song and dance to avoid allocating |
| * a Rectangle object if we don't have to. |
| */ |
| if (view instanceof JComponent) { |
| JComponent c = (JComponent)view; |
| oldX = c.getX(); |
| oldY = c.getY(); |
| } |
| else { |
| Rectangle r = view.getBounds(); |
| oldX = r.x; |
| oldY = r.y; |
| } |
| |
| /* The view scrolls in the opposite direction to mouse |
| * movement. |
| */ |
| int newX = -x; |
| int newY = -y; |
| |
| if ((oldX != newX) || (oldY != newY)) { |
| if (!waitingForRepaint && isBlitting() && canUseWindowBlitter()) { |
| RepaintManager rm = RepaintManager.currentManager(this); |
| // The cast to JComponent will work, if view is not |
| // a JComponent, isBlitting will return false. |
| JComponent jview = (JComponent)view; |
| Rectangle dirty = rm.getDirtyRegion(jview); |
| if (dirty == null || !dirty.contains(jview.getVisibleRect())) { |
| rm.beginPaint(); |
| try { |
| Graphics g = JComponent.safelyGetGraphics(this); |
| flushViewDirtyRegion(g, dirty); |
| view.setLocation(newX, newY); |
| g.setClip(0,0,getWidth(), Math.min(getHeight(), |
| jview.getHeight())); |
| // Repaint the complete component if the blit succeeded |
| // and needsRepaintAfterBlit returns true. |
| repaintAll = (windowBlitPaint(g) && |
| needsRepaintAfterBlit()); |
| g.dispose(); |
| rm.markCompletelyClean((JComponent)getParent()); |
| rm.markCompletelyClean(this); |
| rm.markCompletelyClean(jview); |
| } finally { |
| rm.endPaint(); |
| } |
| } |
| else { |
| // The visible region is dirty, no point in doing copyArea |
| view.setLocation(newX, newY); |
| repaintAll = false; |
| } |
| } |
| else { |
| scrollUnderway = true; |
| // This calls setBounds(), and then repaint(). |
| view.setLocation(newX, newY); |
| repaintAll = false; |
| } |
| fireStateChanged(); |
| } |
| } |
| |
| |
| /** |
| * Returns a rectangle whose origin is <code>getViewPosition</code> |
| * and size is <code>getExtentSize</code>. |
| * This is the visible part of the view, in view coordinates. |
| * |
| * @return a <code>Rectangle</code> giving the visible part of |
| * the view using view coordinates. |
| */ |
| public Rectangle getViewRect() { |
| return new Rectangle(getViewPosition(), getExtentSize()); |
| } |
| |
| |
| /** |
| * Computes the parameters for a blit where the backing store image |
| * currently contains <code>oldLoc</code> in the upper left hand corner |
| * and we're scrolling to <code>newLoc</code>. |
| * The parameters are modified |
| * to return the values required for the blit. |
| * |
| * @param dx the horizontal delta |
| * @param dy the vertical delta |
| * @param blitFrom the <code>Point</code> we're blitting from |
| * @param blitTo the <code>Point</code> we're blitting to |
| * @param blitSize the <code>Dimension</code> of the area to blit |
| * @param blitPaint the area to blit |
| * @return true if the parameters are modified and we're ready to blit; |
| * false otherwise |
| */ |
| protected boolean computeBlit( |
| int dx, |
| int dy, |
| Point blitFrom, |
| Point blitTo, |
| Dimension blitSize, |
| Rectangle blitPaint) |
| { |
| int dxAbs = Math.abs(dx); |
| int dyAbs = Math.abs(dy); |
| Dimension extentSize = getExtentSize(); |
| |
| if ((dx == 0) && (dy != 0) && (dyAbs < extentSize.height)) { |
| if (dy < 0) { |
| blitFrom.y = -dy; |
| blitTo.y = 0; |
| blitPaint.y = extentSize.height + dy; |
| } |
| else { |
| blitFrom.y = 0; |
| blitTo.y = dy; |
| blitPaint.y = 0; |
| } |
| |
| blitPaint.x = blitFrom.x = blitTo.x = 0; |
| |
| blitSize.width = extentSize.width; |
| blitSize.height = extentSize.height - dyAbs; |
| |
| blitPaint.width = extentSize.width; |
| blitPaint.height = dyAbs; |
| |
| return true; |
| } |
| |
| else if ((dy == 0) && (dx != 0) && (dxAbs < extentSize.width)) { |
| if (dx < 0) { |
| blitFrom.x = -dx; |
| blitTo.x = 0; |
| blitPaint.x = extentSize.width + dx; |
| } |
| else { |
| blitFrom.x = 0; |
| blitTo.x = dx; |
| blitPaint.x = 0; |
| } |
| |
| blitPaint.y = blitFrom.y = blitTo.y = 0; |
| |
| blitSize.width = extentSize.width - dxAbs; |
| blitSize.height = extentSize.height; |
| |
| blitPaint.width = dxAbs; |
| blitPaint.height = extentSize.height; |
| |
| return true; |
| } |
| |
| else { |
| return false; |
| } |
| } |
| |
| |
| /** |
| * Returns the size of the visible part of the view in view coordinates. |
| * |
| * @return a <code>Dimension</code> object giving the size of the view |
| */ |
| @Transient |
| public Dimension getExtentSize() { |
| return getSize(); |
| } |
| |
| |
| /** |
| * Converts a size in pixel coordinates to view coordinates. |
| * Subclasses of viewport that support "logical coordinates" |
| * will override this method. |
| * |
| * @param size a <code>Dimension</code> object using pixel coordinates |
| * @return a <code>Dimension</code> object converted to view coordinates |
| */ |
| public Dimension toViewCoordinates(Dimension size) { |
| return new Dimension(size); |
| } |
| |
| /** |
| * Converts a point in pixel coordinates to view coordinates. |
| * Subclasses of viewport that support "logical coordinates" |
| * will override this method. |
| * |
| * @param p a <code>Point</code> object using pixel coordinates |
| * @return a <code>Point</code> object converted to view coordinates |
| */ |
| public Point toViewCoordinates(Point p) { |
| return new Point(p); |
| } |
| |
| |
| /** |
| * Sets the size of the visible part of the view using view coordinates. |
| * |
| * @param newExtent a <code>Dimension</code> object specifying |
| * the size of the view |
| */ |
| public void setExtentSize(Dimension newExtent) { |
| Dimension oldExtent = getExtentSize(); |
| if (!newExtent.equals(oldExtent)) { |
| setSize(newExtent); |
| fireStateChanged(); |
| } |
| } |
| |
| /** |
| * A listener for the view. |
| * <p> |
| * <strong>Warning:</strong> |
| * Serialized objects of this class will not be compatible with |
| * future Swing releases. The current serialization support is |
| * appropriate for short term storage or RMI between applications running |
| * the same version of Swing. As of 1.4, support for long term storage |
| * of all JavaBeans<sup><font size="-2">TM</font></sup> |
| * has been added to the <code>java.beans</code> package. |
| * Please see {@link java.beans.XMLEncoder}. |
| */ |
| protected class ViewListener extends ComponentAdapter implements Serializable |
| { |
| public void componentResized(ComponentEvent e) { |
| fireStateChanged(); |
| revalidate(); |
| } |
| } |
| |
| /** |
| * Creates a listener for the view. |
| * @return a <code>ViewListener</code> |
| */ |
| protected ViewListener createViewListener() { |
| return new ViewListener(); |
| } |
| |
| |
| /** |
| * Subclassers can override this to install a different |
| * layout manager (or <code>null</code>) in the constructor. Returns |
| * the <code>LayoutManager</code> to install on the <code>JViewport</code>. |
| * |
| * @return a <code>LayoutManager</code> |
| */ |
| protected LayoutManager createLayoutManager() { |
| return ViewportLayout.SHARED_INSTANCE; |
| } |
| |
| |
| /** |
| * Adds a <code>ChangeListener</code> to the list that is |
| * notified each time the view's |
| * size, position, or the viewport's extent size has changed. |
| * |
| * @param l the <code>ChangeListener</code> to add |
| * @see #removeChangeListener |
| * @see #setViewPosition |
| * @see #setViewSize |
| * @see #setExtentSize |
| */ |
| public void addChangeListener(ChangeListener l) { |
| listenerList.add(ChangeListener.class, l); |
| } |
| |
| /** |
| * Removes a <code>ChangeListener</code> from the list that's notified each |
| * time the views size, position, or the viewports extent size |
| * has changed. |
| * |
| * @param l the <code>ChangeListener</code> to remove |
| * @see #addChangeListener |
| */ |
| public void removeChangeListener(ChangeListener l) { |
| listenerList.remove(ChangeListener.class, l); |
| } |
| |
| /** |
| * Returns an array of all the <code>ChangeListener</code>s added |
| * to this JViewport with addChangeListener(). |
| * |
| * @return all of the <code>ChangeListener</code>s added or an empty |
| * array if no listeners have been added |
| * @since 1.4 |
| */ |
| public ChangeListener[] getChangeListeners() { |
| return listenerList.getListeners(ChangeListener.class); |
| } |
| |
| /** |
| * Notifies all <code>ChangeListeners</code> when the views |
| * size, position, or the viewports extent size has changed. |
| * |
| * @see #addChangeListener |
| * @see #removeChangeListener |
| * @see EventListenerList |
| */ |
| protected void fireStateChanged() |
| { |
| Object[] listeners = listenerList.getListenerList(); |
| for (int i = listeners.length - 2; i >= 0; i -= 2) { |
| if (listeners[i] == ChangeListener.class) { |
| if (changeEvent == null) { |
| changeEvent = new ChangeEvent(this); |
| } |
| ((ChangeListener)listeners[i + 1]).stateChanged(changeEvent); |
| } |
| } |
| } |
| |
| /** |
| * Always repaint in the parents coordinate system to make sure |
| * only one paint is performed by the <code>RepaintManager</code>. |
| * |
| * @param tm maximum time in milliseconds before update |
| * @param x the <code>x</code> coordinate (pixels over from left) |
| * @param y the <code>y</code> coordinate (pixels down from top) |
| * @param w the width |
| * @param h the height |
| * @see java.awt.Component#update(java.awt.Graphics) |
| */ |
| public void repaint(long tm, int x, int y, int w, int h) { |
| Container parent = getParent(); |
| if(parent != null) |
| parent.repaint(tm,x+getX(),y+getY(),w,h); |
| else |
| super.repaint(tm,x,y,w,h); |
| } |
| |
| |
| /** |
| * Returns a string representation of this <code>JViewport</code>. |
| * This method |
| * is intended to be used only for debugging purposes, and the |
| * content and format of the returned string may vary between |
| * implementations. The returned string may be empty but may not |
| * be <code>null</code>. |
| * |
| * @return a string representation of this <code>JViewport</code> |
| */ |
| protected String paramString() { |
| String isViewSizeSetString = (isViewSizeSet ? |
| "true" : "false"); |
| String lastPaintPositionString = (lastPaintPosition != null ? |
| lastPaintPosition.toString() : ""); |
| String scrollUnderwayString = (scrollUnderway ? |
| "true" : "false"); |
| |
| return super.paramString() + |
| ",isViewSizeSet=" + isViewSizeSetString + |
| ",lastPaintPosition=" + lastPaintPositionString + |
| ",scrollUnderway=" + scrollUnderwayString; |
| } |
| |
| // |
| // Following is used when doBlit is true. |
| // |
| |
| /** |
| * Notifies listeners of a property change. This is subclassed to update |
| * the <code>windowBlit</code> property. |
| * (The <code>putClientProperty</code> property is final). |
| * |
| * @param propertyName a string containing the property name |
| * @param oldValue the old value of the property |
| * @param newValue the new value of the property |
| */ |
| protected void firePropertyChange(String propertyName, Object oldValue, |
| Object newValue) { |
| super.firePropertyChange(propertyName, oldValue, newValue); |
| if (propertyName.equals(EnableWindowBlit)) { |
| if (newValue != null) { |
| setScrollMode(BLIT_SCROLL_MODE); |
| } else { |
| setScrollMode(SIMPLE_SCROLL_MODE); |
| } |
| } |
| } |
| |
| /** |
| * Returns true if the component needs to be completely repainted after |
| * a blit and a paint is received. |
| */ |
| private boolean needsRepaintAfterBlit() { |
| // Find the first heavy weight ancestor. isObscured and |
| // canDetermineObscurity are only appropriate for heavy weights. |
| Component heavyParent = getParent(); |
| |
| while (heavyParent != null && heavyParent.isLightweight()) { |
| heavyParent = heavyParent.getParent(); |
| } |
| |
| if (heavyParent != null) { |
| ComponentPeer peer = heavyParent.getPeer(); |
| |
| if (peer != null && peer.canDetermineObscurity() && |
| !peer.isObscured()) { |
| // The peer says we aren't obscured, therefore we can assume |
| // that we won't later be messaged to paint a portion that |
| // we tried to blit that wasn't valid. |
| // It is certainly possible that when we blited we were |
| // obscured, and by the time this is invoked we aren't, but the |
| // chances of that happening are pretty slim. |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| private Timer createRepaintTimer() { |
| Timer timer = new Timer(300, new ActionListener() { |
| public void actionPerformed(ActionEvent ae) { |
| // waitingForRepaint will be false if a paint came down |
| // with the complete clip rect, in which case we don't |
| // have to cause a repaint. |
| if (waitingForRepaint) { |
| repaint(); |
| } |
| } |
| }); |
| timer.setRepeats(false); |
| return timer; |
| } |
| |
| /** |
| * If the repaint manager has a dirty region for the view, the view is |
| * asked to paint. |
| * |
| * @param g the <code>Graphics</code> context within which to paint |
| */ |
| private void flushViewDirtyRegion(Graphics g, Rectangle dirty) { |
| JComponent view = (JComponent) getView(); |
| if(dirty != null && dirty.width > 0 && dirty.height > 0) { |
| dirty.x += view.getX(); |
| dirty.y += view.getY(); |
| Rectangle clip = g.getClipBounds(); |
| if (clip == null) { |
| // Only happens in 1.2 |
| g.setClip(0, 0, getWidth(), getHeight()); |
| } |
| g.clipRect(dirty.x, dirty.y, dirty.width, dirty.height); |
| clip = g.getClipBounds(); |
| // Only paint the dirty region if it is visible. |
| if (clip.width > 0 && clip.height > 0) { |
| paintView(g); |
| } |
| } |
| } |
| |
| /** |
| * Used when blitting. |
| * |
| * @param g the <code>Graphics</code> context within which to paint |
| * @return true if blitting succeeded; otherwise false |
| */ |
| private boolean windowBlitPaint(Graphics g) { |
| int width = getWidth(); |
| int height = getHeight(); |
| |
| if ((width == 0) || (height == 0)) { |
| return false; |
| } |
| |
| boolean retValue; |
| RepaintManager rm = RepaintManager.currentManager(this); |
| JComponent view = (JComponent) getView(); |
| |
| if (lastPaintPosition == null || |
| lastPaintPosition.equals(getViewLocation())) { |
| paintView(g); |
| retValue = false; |
| } else { |
| // The image was scrolled. Manipulate the backing store and flush |
| // it to g. |
| Point blitFrom = new Point(); |
| Point blitTo = new Point(); |
| Dimension blitSize = new Dimension(); |
| Rectangle blitPaint = new Rectangle(); |
| |
| Point newLocation = getViewLocation(); |
| int dx = newLocation.x - lastPaintPosition.x; |
| int dy = newLocation.y - lastPaintPosition.y; |
| boolean canBlit = computeBlit(dx, dy, blitFrom, blitTo, blitSize, |
| blitPaint); |
| if (!canBlit) { |
| paintView(g); |
| retValue = false; |
| } else { |
| // Prepare the rest of the view; the part that has just been |
| // exposed. |
| Rectangle r = view.getBounds().intersection(blitPaint); |
| r.x -= view.getX(); |
| r.y -= view.getY(); |
| |
| blitDoubleBuffered(view, g, r.x, r.y, r.width, r.height, |
| blitFrom.x, blitFrom.y, blitTo.x, blitTo.y, |
| blitSize.width, blitSize.height); |
| retValue = true; |
| } |
| } |
| lastPaintPosition = getViewLocation(); |
| return retValue; |
| } |
| |
| // |
| // NOTE: the code below uses paintForceDoubleBuffered for historical |
| // reasons. If we're going to allow a blit we've already accounted for |
| // everything that paintImmediately and _paintImmediately does, for that |
| // reason we call into paintForceDoubleBuffered to diregard whether or |
| // not setDoubleBuffered(true) was invoked on the view. |
| // |
| |
| private void blitDoubleBuffered(JComponent view, Graphics g, |
| int clipX, int clipY, int clipW, int clipH, |
| int blitFromX, int blitFromY, int blitToX, int blitToY, |
| int blitW, int blitH) { |
| // NOTE: |
| // blitFrom/blitTo are in JViewport coordinates system |
| // not the views coordinate space. |
| // clip* are in the views coordinate space. |
| RepaintManager rm = RepaintManager.currentManager(this); |
| int bdx = blitToX - blitFromX; |
| int bdy = blitToY - blitFromY; |
| |
| // Shift the scrolled region |
| rm.copyArea(this, g, blitFromX, blitFromY, blitW, blitH, bdx, bdy, |
| false); |
| |
| // Paint the newly exposed region. |
| int x = view.getX(); |
| int y = view.getY(); |
| g.translate(x, y); |
| g.setClip(clipX, clipY, clipW, clipH); |
| view.paintForceDoubleBuffered(g); |
| g.translate(-x, -y); |
| } |
| |
| /** |
| * Called to paint the view, usually when <code>blitPaint</code> |
| * can not blit. |
| * |
| * @param g the <code>Graphics</code> context within which to paint |
| */ |
| private void paintView(Graphics g) { |
| Rectangle clip = g.getClipBounds(); |
| JComponent view = (JComponent)getView(); |
| |
| if (view.getWidth() >= getWidth()) { |
| // Graphics is relative to JViewport, need to map to view's |
| // coordinates space. |
| int x = view.getX(); |
| int y = view.getY(); |
| g.translate(x, y); |
| g.setClip(clip.x - x, clip.y - y, clip.width, clip.height); |
| view.paintForceDoubleBuffered(g); |
| g.translate(-x, -y); |
| g.setClip(clip.x, clip.y, clip.width, clip.height); |
| } |
| else { |
| // To avoid any problems that may result from the viewport being |
| // bigger than the view we start painting from the viewport. |
| try { |
| inBlitPaint = true; |
| paintForceDoubleBuffered(g); |
| } finally { |
| inBlitPaint = false; |
| } |
| } |
| } |
| |
| /** |
| * Returns true if the viewport is not obscured by one of its ancestors, |
| * or its ancestors children and if the viewport is showing. Blitting |
| * when the view isn't showing will work, |
| * or rather <code>copyArea</code> will work, |
| * but will not produce the expected behavior. |
| */ |
| private boolean canUseWindowBlitter() { |
| if (!isShowing() || (!(getParent() instanceof JComponent) && |
| !(getView() instanceof JComponent))) { |
| return false; |
| } |
| if (isPainting()) { |
| // We're in the process of painting, don't blit. If we were |
| // to blit we would draw on top of what we're already drawing, |
| // so bail. |
| return false; |
| } |
| |
| Rectangle dirtyRegion = RepaintManager.currentManager(this). |
| getDirtyRegion((JComponent)getParent()); |
| |
| if (dirtyRegion != null && dirtyRegion.width > 0 && |
| dirtyRegion.height > 0) { |
| // Part of the scrollpane needs to be repainted too, don't blit. |
| return false; |
| } |
| |
| Rectangle clip = new Rectangle(0,0,getWidth(),getHeight()); |
| Rectangle oldClip = new Rectangle(); |
| Rectangle tmp2 = null; |
| Container parent; |
| Component lastParent = null; |
| int x, y, w, h; |
| |
| for(parent = this; parent != null && isLightweightComponent(parent); parent = parent.getParent()) { |
| x = parent.getX(); |
| y = parent.getY(); |
| w = parent.getWidth(); |
| h = parent.getHeight(); |
| |
| oldClip.setBounds(clip); |
| SwingUtilities.computeIntersection(0, 0, w, h, clip); |
| if(!clip.equals(oldClip)) |
| return false; |
| |
| if(lastParent != null && parent instanceof JComponent && |
| !((JComponent)parent).isOptimizedDrawingEnabled()) { |
| Component comps[] = parent.getComponents(); |
| int index = 0; |
| |
| for(int i = comps.length - 1 ;i >= 0; i--) { |
| if(comps[i] == lastParent) { |
| index = i - 1; |
| break; |
| } |
| } |
| |
| while(index >= 0) { |
| tmp2 = comps[index].getBounds(tmp2); |
| |
| if(tmp2.intersects(clip)) |
| return false; |
| index--; |
| } |
| } |
| clip.x += x; |
| clip.y += y; |
| lastParent = parent; |
| } |
| if (parent == null) { |
| // No Window parent. |
| return false; |
| } |
| return true; |
| } |
| |
| |
| ///////////////// |
| // Accessibility support |
| //////////////// |
| |
| /** |
| * Gets the AccessibleContext associated with this JViewport. |
| * For viewports, the AccessibleContext takes the form of an |
| * AccessibleJViewport. |
| * A new AccessibleJViewport instance is created if necessary. |
| * |
| * @return an AccessibleJViewport that serves as the |
| * AccessibleContext of this JViewport |
| */ |
| public AccessibleContext getAccessibleContext() { |
| if (accessibleContext == null) { |
| accessibleContext = new AccessibleJViewport(); |
| } |
| return accessibleContext; |
| } |
| |
| /** |
| * This class implements accessibility support for the |
| * <code>JViewport</code> class. It provides an implementation of the |
| * Java Accessibility API appropriate to viewport user-interface elements. |
| * <p> |
| * <strong>Warning:</strong> |
| * Serialized objects of this class will not be compatible with |
| * future Swing releases. The current serialization support is |
| * appropriate for short term storage or RMI between applications running |
| * the same version of Swing. As of 1.4, support for long term storage |
| * of all JavaBeans<sup><font size="-2">TM</font></sup> |
| * has been added to the <code>java.beans</code> package. |
| * Please see {@link java.beans.XMLEncoder}. |
| */ |
| protected class AccessibleJViewport extends AccessibleJComponent { |
| /** |
| * Get the role of this object. |
| * |
| * @return an instance of AccessibleRole describing the role of |
| * the object |
| */ |
| public AccessibleRole getAccessibleRole() { |
| return AccessibleRole.VIEWPORT; |
| } |
| } // inner class AccessibleJViewport |
| } |
