imageview.java

Mobile 应用程序使用 Java Micro Edition (Java ME) 平台

	fBounds.setBounds(rect);
        paintHighlights(g, a);
        paintBorder(g, rect);
        if (clip != null) {
            g.clipRect(rect.x + leftInset, rect.y + topInset,
                       rect.width - leftInset - rightInset,
                       rect.height - topInset - bottomInset);
        }
        if (image != null) {
            if (!hasPixels(image)) {
                // No pixels yet, use the default
                Icon icon = (image == null) ? getNoImageIcon() :
                                               getLoadingImageIcon();

                if (icon != null) {
                    icon.paintIcon(getContainer(), g, rect.x + leftInset,
                                   rect.y + topInset);
                }
            }
            else {
                // Draw the image
                g.drawImage(image, rect.x + leftInset, rect.y + topInset,
                            width, height, imageObserver);
            }
        }
        else {
            Icon icon = getNoImageIcon();

            if (icon != null) {
                icon.paintIcon(getContainer(), g, rect.x + leftInset,
                               rect.y + topInset);
            }
            View view = getAltView();
            // Paint the view representing the alt text, if its non-null
            if (view != null && ((state & WIDTH_FLAG) == 0 ||
                                 width > DEFAULT_WIDTH)) {
                // Assume layout along the y direction
                Rectangle altRect = new Rectangle
                    (rect.x + leftInset + DEFAULT_WIDTH, rect.y + topInset,
                     rect.width - leftInset - rightInset - DEFAULT_WIDTH,
                     rect.height - topInset - bottomInset);

                view.paint(g, altRect);
            }
        }
        if (clip != null) {
            // Reset clip.
            g.setClip(clip.x, clip.y, clip.width, clip.height);
        }
    }

    private void paintHighlights(Graphics g, Shape shape) {
	if (container instanceof JTextComponent) {
	    JTextComponent tc = (JTextComponent)container;
	    Highlighter h = tc.getHighlighter();
	    if (h instanceof LayeredHighlighter) {
		((LayeredHighlighter)h).paintLayeredHighlights
		    (g, getStartOffset(), getEndOffset(), shape, tc, this);
	    }
	}
    }

    private void paintBorder(Graphics g, Rectangle rect) {
        Color color = borderColor;

        if ((borderSize > 0 || image == null) && color != null) {
            int xOffset = leftInset - borderSize;
            int yOffset = topInset - borderSize;
            g.setColor(color);
            int n = (image == null) ? 1 : borderSize;
	    for (int counter = 0; counter < n; counter++) {
	        g.drawRect(rect.x + xOffset + counter,
                           rect.y + yOffset + counter,
                           rect.width - counter - counter - xOffset -xOffset-1,
                           rect.height - counter - counter -yOffset-yOffset-1);
            }
        }
    }

    /**
     * Determines the preferred span for this view along an
     * axis.
     *
     * @param axis may be either X_AXIS or Y_AXIS
     * @return   the span the view would like to be rendered into;
     *           typically the view is told to render into the span
     *           that is returned, although there is no guarantee;  
     *           the parent may choose to resize or break the view
     */
    public float getPreferredSpan(int axis) {
        sync();

        // If the attributes specified a width/height, always use it!
        if (axis == View.X_AXIS && (state & WIDTH_FLAG) == WIDTH_FLAG) {
            getPreferredSpanFromAltView(axis);
            return width + leftInset + rightInset;
        }
        if (axis == View.Y_AXIS && (state & HEIGHT_FLAG) == HEIGHT_FLAG) {
            getPreferredSpanFromAltView(axis);
            return height + topInset + bottomInset;
        }

        Image image = getImage();

        if (image != null) {
            switch (axis) {
            case View.X_AXIS:
                return width + leftInset + rightInset;
            case View.Y_AXIS:
                return height + topInset + bottomInset;
            default:
                throw new IllegalArgumentException("Invalid axis: " + axis);
            }
        }
        else {
            View view = getAltView();
            float retValue = 0f;

            if (view != null) {
                retValue = view.getPreferredSpan(axis);
            }
            switch (axis) {
            case View.X_AXIS:
                return retValue + (float)(width + leftInset + rightInset);
            case View.Y_AXIS:
                return retValue + (float)(height + topInset + bottomInset);
            default:
                throw new IllegalArgumentException("Invalid axis: " + axis);
            }
        }
    }

    /**
     * Determines the desired alignment for this view along an
     * axis.  This is implemented to give the alignment to the
     * bottom of the icon along the y axis, and the default
     * along the x axis.
     *
     * @param axis may be either X_AXIS or Y_AXIS
     * @return the desired alignment; this should be a value
     *   between 0.0 and 1.0 where 0 indicates alignment at the
     *   origin and 1.0 indicates alignment to the full span
     *   away from the origin; an alignment of 0.5 would be the
     *   center of the view
     */
    public float getAlignment(int axis) {
	switch (axis) {
	case View.Y_AXIS:
	    return vAlign;
	default:
	    return super.getAlignment(axis);
	}
    }

    /**
     * Provides a mapping from the document model coordinate space
     * to the coordinate space of the view mapped to it.
     *
     * @param pos the position to convert
     * @param a the allocated region to render into
     * @return the bounding box of the given position
     * @exception BadLocationException  if the given position does not represent a
     *   valid location in the associated document
     * @see View#modelToView
     */
    public Shape modelToView(int pos, Shape a, Position.Bias b) throws BadLocationException {
	int p0 = getStartOffset();
	int p1 = getEndOffset();
	if ((pos >= p0) && (pos <= p1)) {
	    Rectangle r = a.getBounds();
	    if (pos == p1) {
		r.x += r.width;
	    }
	    r.width = 0;
	    return r;
	}
	return null;
    }

    /**
     * Provides a mapping from the view coordinate space to the logical
     * coordinate space of the model.
     *
     * @param x the X coordinate
     * @param y the Y coordinate
     * @param a the allocated region to render into
     * @return the location within the model that best represents the
     *  given point of view
     * @see View#viewToModel
     */
    public int viewToModel(float x, float y, Shape a, Position.Bias[] bias) {
	Rectangle alloc = (Rectangle) a;
	if (x < alloc.x + alloc.width) {
	    bias[0] = Position.Bias.Forward;
	    return getStartOffset();
	}
	bias[0] = Position.Bias.Backward;
	return getEndOffset();
    }

    /**
     * Sets the size of the view.  This should cause 
     * layout of the view if it has any layout duties.
     *
     * @param width the width >= 0
     * @param height the height >= 0
     */
    public void setSize(float width, float height) {
        sync();

        if (getImage() == null) {
            View view = getAltView();

            if (view != null) {
		view.setSize(Math.max(0f, width - (float)(DEFAULT_WIDTH + leftInset + rightInset)),
			     Math.max(0f, height - (float)(topInset + bottomInset)));
            }
        }
    }

    /**
     * Returns true if this image within a link?
     */
    private boolean isLink() {
	return ((state & LINK_FLAG) == LINK_FLAG);
    }

    /**
     * Returns true if the passed in image has a non-zero width and height.
     */
    private boolean hasPixels(Image image) {
        return image != null &&
            (image.getHeight(imageObserver) > 0) &&
            (image.getWidth(imageObserver) > 0);
    }

    /**
     * Returns the preferred span of the View used to display the alt text,
     * or 0 if the view does not exist.
     */
    private float getPreferredSpanFromAltView(int axis) {
        if (getImage() == null) {
            View view = getAltView();

            if (view != null) {
                return view.getPreferredSpan(axis);
            }
        }
        return 0f;
    }

    /**
     * Request that this view be repainted.
     * Assumes the view is still at its last-drawn location.
     */
    private void repaint(long delay) {
    	if (container != null && fBounds != null) {
	    container.repaint(delay, fBounds.x, fBounds.y, fBounds.width,
                               fBounds.height);
    	}
    }

    /**
     * Convenience method for getting an integer attribute from the elements
     * AttributeSet.
     */
    private int getIntAttr(HTML.Attribute name, int deflt) {
    	AttributeSet attr = getElement().getAttributes();
    	if (attr.isDefined(name)) {		// does not check parents!
    	    int i;
 	    String val = (String)attr.getAttribute(name);
 	    if (val == null) {
 	    	i = deflt;
            }
 	    else {
 	    	try{
 	            i = Math.max(0, Integer.parseInt(val));
 	    	}catch( NumberFormatException x ) {
 	    	    i = deflt;
 	    	}
            }
	    return i;
	} else
	    return deflt;
    }

    /**
     * Makes sure the necessary properties and image is loaded.
     */
    private void sync() {
        int s = state;
        if ((s & RELOAD_IMAGE_FLAG) != 0) {
            refreshImage();
        }
        s = state;
        if ((s & RELOAD_FLAG) != 0) {
            synchronized(this) {
                state = (state | RELOAD_FLAG) ^ RELOAD_FLAG;
            }
            setPropertiesFromAttributes();
        }
    }

    /**
     * Loads the image and updates the size accordingly. This should be
     * invoked instead of invoking <code>loadImage</code> or
     * <code>updateImageSize</code> directly.
     */
    private void refreshImage() {
	synchronized(this) {
            // clear out width/height/realoadimage flag and set loading flag
            state = (state | LOADING_FLAG | RELOAD_IMAGE_FLAG | WIDTH_FLAG |
                     HEIGHT_FLAG) ^ (WIDTH_FLAG | HEIGHT_FLAG |
                                     RELOAD_IMAGE_FLAG);
            image = null;
            width = height = 0;
        }

        try {
            // Load the image
            loadImage();

            // And update the size params
            updateImageSize();
        }
        finally {
            synchronized(this) {