FileDocCategorySizeDatePackage
ParagraphView.javaAPI DocJava SE 6 API9199Tue Jun 10 00:27:00 BST 2008javax.swing.text.html

ParagraphView

public class ParagraphView extends ParagraphView
Displays the a paragraph, and uses css attributes for its configuration.
author
Timothy Prinzing
version
1.30 11/17/05

Fields Summary
private AttributeSet
attr
private StyleSheet$BoxPainter
painter
private CSS$LengthValue
cssWidth
private CSS$LengthValue
cssHeight
Constructors Summary
public ParagraphView(Element elem)
Constructs a ParagraphView for the given element.

param
elem the element that this view is responsible for

	super(elem);
    
Methods Summary
protected javax.swing.SizeRequirementscalculateMinorAxisRequirements(int axis, javax.swing.SizeRequirements r)
Calculate the needs for the paragraph along the minor axis. This implemented to use the requirements of the superclass, modified slightly to set a minimum span allowed. Typical html rendering doesn't let the view size shrink smaller than the length of the longest word.

	r = super.calculateMinorAxisRequirements(axis, r);

        if (!BlockView.spanSetFromAttributes(axis, r, cssWidth, cssHeight)) {
            // PENDING(prinz) Need to make this better so it doesn't require
            // InlineView and works with font changes within the word.

            // find the longest minimum span.
            float min = 0;
            int n = getLayoutViewCount();
            for (int i = 0; i < n; i++) {
                View v = getLayoutView(i);
                if (v instanceof InlineView) {
                    float wordSpan = ((InlineView) v).getLongestWordSpan();
                    min = Math.max(wordSpan, min);
                } else {
                    min = Math.max(v.getMinimumSpan(axis), min);
                }
            }
            r.minimum = Math.max(r.minimum, (int) min);
            r.preferred = Math.max(r.minimum,  r.preferred);
            r.maximum = Math.max(r.preferred, r.maximum);
        }
        else {
            // Offset by the margins so that pref/min/max return the
            // right value.
            int margin = (axis == X_AXIS) ? getLeftInset() + getRightInset() :
                                            getTopInset() + getBottomInset();
            r.minimum -= margin;
            r.preferred -= margin;
            r.maximum -= margin;
        }
	return r;
    
public javax.swing.text.AttributeSetgetAttributes()
Fetches the attributes to use when rendering. This is implemented to multiplex the attributes specified in the model with a StyleSheet.

	if (attr == null) {
	    StyleSheet sheet = getStyleSheet();
	    attr = sheet.getViewAttributes(this);
	}
	return attr;
    
public floatgetMaximumSpan(int axis)
Determines the maximum span for this view along an axis. Returns 0 if the view is not visible, otherwise it calls the superclass method ot get the maximum span.

param
axis may be either View.X_AXIS or View.Y_AXIS
return
the maximum span the view can be rendered into
see
javax.swing.text.ParagraphView#getMaximumSpan

	if (!isVisible()) {
	    return 0;
	}
	return super.getMaximumSpan(axis);
    
public floatgetMinimumSpan(int axis)
Determines the minimum span for this view along an axis. Returns 0 if the view is not visible, otherwise it calls the superclass method to get the minimum span.

param
axis may be either View.X_AXIS or View.Y_AXIS
return
the minimum span the view can be rendered into
see
javax.swing.text.ParagraphView#getMinimumSpan

	if (!isVisible()) {
	    return 0;
	}
	return super.getMinimumSpan(axis);
    
public floatgetPreferredSpan(int axis)
Determines the preferred span for this view. Returns 0 if the view is not visible, otherwise it calls the superclass method to get the preferred span. axis.

param
axis may be either View.X_AXIS or View.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
see
javax.swing.text.ParagraphView#getPreferredSpan

	if (!isVisible()) {
	    return 0;
	}
	return super.getPreferredSpan(axis);
    
protected javax.swing.text.html.StyleSheetgetStyleSheet()

	HTMLDocument doc = (HTMLDocument) getDocument();
	return doc.getStyleSheet();
    
public booleanisVisible()
Indicates whether or not this view should be displayed. If none of the children wish to be displayed and the only visible child is the break that ends the paragraph, the paragraph will not be considered visible. Otherwise, it will be considered visible and return true.

return
true if the paragraph should be displayed

	
	int n = getLayoutViewCount() - 1;
	for (int i = 0; i < n; i++) {
	    View v = getLayoutView(i);
	    if (v.isVisible()) {
		return true;
	    }
	}
	if (n > 0) {
	    View v = getLayoutView(n);
	    if ((v.getEndOffset() - v.getStartOffset()) == 1) {
		return false;
	    }
	}
	// If it's the last paragraph and not editable, it shouldn't
	// be visible.
	if (getStartOffset() == getDocument().getLength()) {
	    boolean editable = false;
	    Component c = getContainer();
	    if (c instanceof JTextComponent) {
		editable = ((JTextComponent)c).isEditable();
	    }
	    if (!editable) {
		return false;
	    }
	}
	return true;
    
public voidpaint(java.awt.Graphics g, java.awt.Shape a)
Renders using the given rendering surface and area on that surface. This is implemented to delgate to the superclass after stashing the base coordinate for tab calculations.

param
g the rendering surface to use
param
a the allocated region to render into
see
View#paint

        if (a == null) {
            return;
        }
        
	Rectangle r;
	if (a instanceof Rectangle) {
	    r = (Rectangle) a;
	} else {
	    r = a.getBounds();
	}
	painter.paint(g, r.x, r.y, r.width, r.height, this);
        super.paint(g, a);
    
public voidsetParent(javax.swing.text.View parent)
Establishes the parent view for this view. This is guaranteed to be called before any other methods if the parent view is functioning properly.

This is implemented to forward to the superclass as well as call the setPropertiesFromAttributes method to set the paragraph properties from the css attributes. The call is made at this time to ensure the ability to resolve upward through the parents view attributes.

param
parent the new parent, or null if the view is being removed from a parent it was previously added to

	super.setParent(parent);
        if (parent != null) {
	    setPropertiesFromAttributes();
        }
    
protected voidsetPropertiesFromAttributes()
Sets up the paragraph from css attributes instead of the values found in StyleConstants (i.e. which are used by the superclass). Since

	StyleSheet sheet = getStyleSheet();
	attr = sheet.getViewAttributes(this);
	painter = sheet.getBoxPainter(attr);
	if (attr != null) {
	    super.setPropertiesFromAttributes();
	    setInsets((short) painter.getInset(TOP, this),
		      (short) painter.getInset(LEFT, this),
		      (short) painter.getInset(BOTTOM, this),
		      (short) painter.getInset(RIGHT, this));
	    Object o = attr.getAttribute(CSS.Attribute.TEXT_ALIGN);
	    if (o != null) {
		// set horizontal alignment
		String ta = o.toString();
		if (ta.equals("left")) {
		    setJustification(StyleConstants.ALIGN_LEFT);
		} else if (ta.equals("center")) {
		    setJustification(StyleConstants.ALIGN_CENTER);
		} else if (ta.equals("right")) {
		    setJustification(StyleConstants.ALIGN_RIGHT);
		} else if (ta.equals("justify")) {
		    setJustification(StyleConstants.ALIGN_JUSTIFIED);
		}
	    }
            // Get the width/height
            cssWidth = (CSS.LengthValue)attr.getAttribute(
                                        CSS.Attribute.WIDTH);
            cssHeight = (CSS.LengthValue)attr.getAttribute(
                                         CSS.Attribute.HEIGHT);
	}