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Diffstat (limited to 'libjava/classpath/javax/swing/text/html/ImageView.java')
-rw-r--r-- | libjava/classpath/javax/swing/text/html/ImageView.java | 441 |
1 files changed, 441 insertions, 0 deletions
diff --git a/libjava/classpath/javax/swing/text/html/ImageView.java b/libjava/classpath/javax/swing/text/html/ImageView.java new file mode 100644 index 00000000000..84b021070a9 --- /dev/null +++ b/libjava/classpath/javax/swing/text/html/ImageView.java @@ -0,0 +1,441 @@ +package javax.swing.text.html; + +import gnu.javax.swing.text.html.CombinedAttributes; +import gnu.javax.swing.text.html.ImageViewIconFactory; + +import java.awt.Graphics; +import java.awt.Image; +import java.awt.MediaTracker; +import java.awt.Rectangle; +import java.awt.Shape; +import java.net.MalformedURLException; +import java.net.URL; + +import javax.swing.Icon; +import javax.swing.ImageIcon; +import javax.swing.text.AttributeSet; +import javax.swing.text.BadLocationException; +import javax.swing.text.Document; +import javax.swing.text.Element; +import javax.swing.text.View; +import javax.swing.text.Position.Bias; +import javax.swing.text.html.HTML.Attribute; + +/** + * A view, representing a single image, represented by the HTML IMG tag. + * + * @author Audrius Meskauskas (AudriusA@Bioinformatics.org) + */ +public class ImageView extends View +{ + /** + * True if the image loads synchronuosly (on demand). By default, the image + * loads asynchronuosly. + */ + boolean loadOnDemand; + + /** + * The image icon, wrapping the image, + */ + ImageIcon imageIcon; + + /** + * The image state. + */ + byte imageState = MediaTracker.LOADING; + + /** + * Creates the image view that represents the given element. + * + * @param element the element, represented by this image view. + */ + public ImageView(Element element) + { + super(element); + } + + /** + * Load or reload the image. This method initiates the image reloading. After + * the image is ready, the repaint event will be scheduled. The current image, + * if it already exists, will be discarded. + * + * @param itsTime + * also load if the "on demand" property is set + */ + void reloadImage(boolean itsTime) + { + URL url = getImageURL(); + if (url == null) + imageState = (byte) MediaTracker.ERRORED; + else if (!(loadOnDemand && !itsTime)) + imageIcon = new ImageIcon(url); + else + imageState = (byte) MediaTracker.LOADING; + } + + /** + * Get the image alignment. This method works handling standart alignment + * attributes in the HTML IMG tag (align = top bottom middle left right). + * Depending from the parameter, either horizontal or vertical alingment + * information is returned. + * + * @param axis - + * either X_AXIS or Y_AXIS + */ + public float getAlignment(int axis) + { + AttributeSet attrs = getAttributes(); + Object al = attrs.getAttribute(Attribute.ALIGN); + + // Default is top left aligned. + if (al == null) + return 0.0f; + + String align = al.toString(); + + if (axis == View.X_AXIS) + { + if (align.equals("middle")) + return 0.5f; + else if (align.equals("left")) + return 0.0f; + else if (align.equals("right")) + return 1.0f; + else + return 0.0f; + } + else if (axis == View.Y_AXIS) + { + if (align.equals("middle")) + return 0.5f; + else if (align.equals("top")) + return 0.0f; + else if (align.equals("bottom")) + return 1.0f; + else + return 0.0f; + } + else + throw new IllegalArgumentException("axis " + axis); + } + + /** + * Get the text that should be shown as the image replacement and also as the + * image tool tip text. The method returns the value of the attribute, having + * the name {@link Attribute#ALT}. If there is no such attribute, the image + * name from the url is returned. If the URL is not available, the empty + * string is returned. + */ + public String getAltText() + { + Object rt = getAttributes().getAttribute(Attribute.ALT); + if (rt != null) + return rt.toString(); + else + { + URL u = getImageURL(); + if (u == null) + return ""; + else + return u.getFile(); + } + } + + /** + * Returns the combination of the document and the style sheet attributes. + */ + public AttributeSet getAttributes() + { + StyleSheet styles = getStyleSheet(); + if (styles == null) + return super.getAttributes(); + else + return CombinedAttributes.combine(super.getAttributes(), + styles.getViewAttributes(this)); + } + + /** + * Get the image to render. May return null if the image is not yet loaded. + */ + public Image getImage() + { + if (imageIcon == null) + return null; + else + return imageIcon.getImage(); + } + + /** + * Get the URL location of the image to render. If this method returns null, + * the "no image" icon is rendered instead. By defaul, url must be present as + * the "src" property of the IMG tag. If it is missing, null is returned and + * the "no image" icon is rendered. + * + * @return the URL location of the image to render. + */ + public URL getImageURL() + { + Object url = getAttributes().getAttribute(Attribute.SRC); + if (url == null) + return null; + + try + { + return new URL(url.toString()); + } + catch (MalformedURLException e) + { + // The URL is malformed - no image. + return null; + } + } + + /** + * Get the icon that should be displayed while the image is loading and hence + * not yet available. + * + * @return an icon, showing a non broken sheet of paper with image. + */ + public Icon getLoadingImageIcon() + { + return ImageViewIconFactory.getLoadingImageIcon(); + } + + /** + * Get the image loading strategy. + * + * @return false (default) if the image is loaded when the view is + * constructed, true if the image is only loaded on demand when + * rendering. + */ + public boolean getLoadsSynchronously() + { + return loadOnDemand; + } + + /** + * Get the icon that should be displayed when the image is not available. + * + * @return an icon, showing a broken sheet of paper with image. + */ + public Icon getNoImageIcon() + { + return ImageViewIconFactory.getNoImageIcon(); + } + + /** + * Get the preferred span of the image along the axis. The image size is first + * requested to the attributes {@link Attribute#WIDTH} and + * {@link Attribute#HEIGHT}. If they are missing, and the image is already + * loaded, the image size is returned. If there are no attributes, and the + * image is not loaded, zero is returned. + * + * @param axis - + * either X_AXIS or Y_AXIS + * @return either width of height of the image, depending on the axis. + */ + public float getPreferredSpan(int axis) + { + AttributeSet attrs = getAttributes(); + + Image image = getImage(); + + if (axis == View.X_AXIS) + { + Object w = attrs.getAttribute(Attribute.WIDTH); + if (w != null) + return Integer.parseInt(w.toString()); + else if (image != null) + return image.getWidth(getContainer()); + else + return getNoImageIcon().getIconWidth(); + } + else if (axis == View.Y_AXIS) + { + Object w = attrs.getAttribute(Attribute.HEIGHT); + if (w != null) + return Integer.parseInt(w.toString()); + else if (image != null) + return image.getHeight(getContainer()); + else + return getNoImageIcon().getIconHeight(); + } + else + throw new IllegalArgumentException("axis " + axis); + } + + /** + * Get the associated style sheet from the document. + * + * @return the associated style sheet. + */ + protected StyleSheet getStyleSheet() + { + Document d = getElement().getDocument(); + if (d instanceof HTMLDocument) + return ((HTMLDocument) d).getStyleSheet(); + else + return null; + } + + /** + * Get the tool tip text. This is overridden to return the value of the + * {@link #getAltText()}. The parameters are ignored. + * + * @return that is returned by getAltText(). + */ + public String getToolTipText(float x, float y, Shape shape) + { + return getAltText(); + } + + /** + * Paints the image or one of the two image state icons. The image is resized + * to the shape bounds. If there is no image available, the alternative text + * is displayed besides the image state icon. + * + * @param g + * the Graphics, used for painting. + * @param bounds + * the bounds of the region where the image or replacing icon must be + * painted. + */ + public void paint(Graphics g, Shape bounds) + { + Rectangle r = bounds.getBounds(); + + if (imageIcon == null) + + { + // Loading image on demand, rendering the loading icon so far. + reloadImage(true); + + // The reloadImage sets the imageIcon, unless the URL is broken + // or malformed. + if (imageIcon != null) + { + if (imageIcon.getImageLoadStatus() != MediaTracker.COMPLETE) + { + // Render "not ready" icon, unless the image is ready + // immediately. + renderIcon(g, r, getLoadingImageIcon()); + // Add the listener to repaint when the icon will be ready. + imageIcon.setImageObserver(getContainer()); + return; + } + } + else + { + renderIcon(g, r, getNoImageIcon()); + return; + } + } + + imageState = (byte) imageIcon.getImageLoadStatus(); + + switch (imageState) + { + case MediaTracker.ABORTED: + case MediaTracker.ERRORED: + renderIcon(g, r, getNoImageIcon()); + break; + case MediaTracker.LOADING: + // If the image is not loaded completely, we still render it, as the + // partial image may be available. + case MediaTracker.COMPLETE: + { + // Paint the scaled image. + Image scaled = imageIcon.getImage().getScaledInstance( + r.width, + r.height, + Image.SCALE_DEFAULT); + ImageIcon painter = new ImageIcon(scaled); + painter.paintIcon(getContainer(), g, r.x, r.y); + } + break; + } + } + + /** + * Render "no image" icon and the alternative "no image" text. The text is + * rendered right from the icon and is aligned to the icon bottom. + */ + private void renderIcon(Graphics g, Rectangle bounds, Icon icon) + { + Shape current = g.getClip(); + try + { + g.setClip(bounds); + if (icon != null) + { + icon.paintIcon(getContainer(), g, bounds.x, bounds.y); + g.drawString(getAltText(), bounds.x + icon.getIconWidth(), + bounds.y + icon.getIconHeight()); + } + } + finally + { + g.setClip(current); + } + } + + /** + * Set if the image should be loaded only when needed (synchronuosly). By + * default, the image loads asynchronuosly. If the image is not yet ready, the + * icon, returned by the {@link #getLoadingImageIcon()}, is displayed. + */ + public void setLoadsSynchronously(boolean load_on_demand) + { + loadOnDemand = load_on_demand; + } + + /** + * Update all cached properties from the attribute set, returned by the + * {@link #getAttributes}. + */ + protected void setPropertiesFromAttributes() + { + // In the current implementation, nothing is cached yet, unless the image + // itself. + imageIcon = null; + } + + /** + * Maps the picture co-ordinates into the image position in the model. As the + * image is not divideable, this is currently implemented always to return the + * start offset. + */ + public int viewToModel(float x, float y, Shape shape, Bias[] bias) + { + return getStartOffset(); + } + + /** + * This is currently implemented always to return the area of the image view, + * as the image is not divideable by character positions. + * + * @param pos character position + * @param area of the image view + * @param bias bias + * + * @return the shape, where the given character position should be mapped. + */ + public Shape modelToView(int pos, Shape area, Bias bias) + throws BadLocationException + { + return area; + } + + /** + * Starts loading the image asynchronuosly. If the image must be loaded + * synchronuosly instead, the {@link #setLoadsSynchronously} must be + * called before calling this method. The passed parameters are not used. + */ + public void setSize(float width, float height) + { + if (imageIcon == null) + reloadImage(false); + } + + +} |