/*
* Copyright (c) 1998, 2013, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
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package javax.swing.text.html;
import java.awt.*;
import javax.swing.SizeRequirements;
import javax.swing.event.DocumentEvent;
import javax.swing.text.Document;
import javax.swing.text.Element;
import javax.swing.text.AttributeSet;
import javax.swing.text.StyleConstants;
import javax.swing.text.View;
import javax.swing.text.ViewFactory;
import javax.swing.text.BadLocationException;
import javax.swing.text.JTextComponent;
/**
* Displays the a paragraph, and uses css attributes for its
* configuration.
*
* @author Timothy Prinzing
*/
public class ParagraphView extends javax.swing.text.ParagraphView {
/**
* Constructs a ParagraphView for the given element.
*
* @param elem the element that this view is responsible for
*/
public ParagraphView(Element elem) {
super(elem);
}
/**
* Establishes the parent view for this view. This is
* guaranteed to be called before any other methods if the
* parent view is functioning properly.
* <p>
* This is implemented
* to forward to the superclass as well as call the
* {@link #setPropertiesFromAttributes 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
*/
public void setParent(View parent) {
super.setParent(parent);
if (parent != null) {
setPropertiesFromAttributes();
}
}
/**
* Fetches the attributes to use when rendering. This is
* implemented to multiplex the attributes specified in the
* model with a StyleSheet.
*/
public AttributeSet getAttributes() {
if (attr == null) {
StyleSheet sheet = getStyleSheet();
attr = sheet.getViewAttributes(this);
}
return attr;
}
/**
* Sets up the paragraph from css attributes instead of
* the values found in StyleConstants (i.e. which are used
* by the superclass). Since
*/
protected void setPropertiesFromAttributes() {
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);
}
}
protected StyleSheet getStyleSheet() {
HTMLDocument doc = (HTMLDocument) getDocument();
return doc.getStyleSheet();
}
/**
* Calculate the needs for the paragraph along the minor axis.
*
* <p>If size requirements are explicitly specified for the paragraph,
* use that requirements. Otherwise, use the requirements of the
* superclass {@link javax.swing.text.ParagraphView}.</p>
*
* <p>If the {@code axis} parameter is neither {@code View.X_AXIS} nor
* {@code View.Y_AXIS}, {@link IllegalArgumentException} is thrown. If the
* {@code r} parameter is {@code null,} a new {@code SizeRequirements}
* object is created, otherwise the supplied {@code SizeRequirements}
* object is returned.</p>
*
* @param axis the minor axis
* @param r the input {@code SizeRequirements} object
* @return the new or adjusted {@code SizeRequirements} object
* @throws IllegalArgumentException if the {@code axis} parameter is invalid
*/
protected SizeRequirements calculateMinorAxisRequirements(
int axis, SizeRequirements r) {
r = super.calculateMinorAxisRequirements(axis, r);
if (BlockView.spanSetFromAttributes(axis, r, cssWidth, cssHeight)) {
// 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;
}
/**
* 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
*/
public boolean isVisible() {
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;
}
/**
* Renders using the given rendering surface and area on that
* surface. This is implemented to delegate 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
*/
public void paint(Graphics g, Shape a) {
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);
}
/**
* 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
*/
public float getPreferredSpan(int axis) {
if (!isVisible()) {
return 0;
}
return super.getPreferredSpan(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 <code>View.X_AXIS</code> or
* <code>View.Y_AXIS</code>
* @return the minimum span the view can be rendered into
* @see javax.swing.text.ParagraphView#getMinimumSpan
*/
public float getMinimumSpan(int axis) {
if (!isVisible()) {
return 0;
}
return super.getMinimumSpan(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 <code>View.X_AXIS</code> or
* <code>View.Y_AXIS</code>
* @return the maximum span the view can be rendered into
* @see javax.swing.text.ParagraphView#getMaximumSpan
*/
public float getMaximumSpan(int axis) {
if (!isVisible()) {
return 0;
}
return super.getMaximumSpan(axis);
}
private AttributeSet attr;
private StyleSheet.BoxPainter painter;
private CSS.LengthValue cssWidth;
private CSS.LengthValue cssHeight;
}