abstractblock.java

JfreeChart 常用图表例子

     * Arranges the contents of the block, with no constraints, and returns 
     * the block size.
     * 
     * @param g2  the graphics device.
     * 
     * @return The block size (in Java2D units, never <code>null</code>).
     */
    public Size2D arrange(Graphics2D g2) {  
        return arrange(g2, RectangleConstraint.NONE);
    }

    /**
     * Arranges the contents of the block, within the given constraints, and 
     * returns the block size.
     * 
     * @param g2  the graphics device.
     * @param constraint  the constraint (<code>null</code> not permitted).
     * 
     * @return The block size (in Java2D units, never <code>null</code>).
     */
    public Size2D arrange(Graphics2D g2, RectangleConstraint constraint) {
        Size2D base = new Size2D(getWidth(), getHeight());
        return constraint.calculateConstrainedSize(base);
    }

    /**
     * Returns the current bounds of the block.
     * 
     * @return The bounds.
     */
    public Rectangle2D getBounds() {
        return this.bounds;
    }
    
    /**
     * Sets the bounds of the block.
     * 
     * @param bounds  the bounds (<code>null</code> not permitted).
     */
    public void setBounds(Rectangle2D bounds) {
        if (bounds == null) {
            throw new IllegalArgumentException("Null 'bounds' argument.");
        }
        this.bounds = bounds;
    }
    
    /**
     * Calculate the width available for content after subtracting 
     * the margin, border and padding space from the specified fixed 
     * width.
     * 
     * @param fixedWidth  the fixed width.
     * 
     * @return The available space.
     */
    protected double trimToContentWidth(double fixedWidth) {
        double result = this.margin.trimWidth(fixedWidth);
        result = this.border.getInsets().trimWidth(result);
        result = this.padding.trimWidth(result);
        return Math.max(result, 0.0);
    }

    /**
     * Calculate the height available for content after subtracting 
     * the margin, border and padding space from the specified fixed 
     * height.
     * 
     * @param fixedHeight  the fixed height.
     * 
     * @return The available space.
     */
    protected double trimToContentHeight(double fixedHeight) {
        double result = this.margin.trimHeight(fixedHeight);
        result = this.border.getInsets().trimHeight(result);
        result = this.padding.trimHeight(result);
        return Math.max(result, 0.0);
    }
    
    /**
     * Returns a constraint for the content of this block that will result in
     * the bounds of the block matching the specified constraint.
     * 
     * @param c  the outer constraint (<code>null</code> not permitted).
     * 
     * @return The content constraint.
     */
    protected RectangleConstraint toContentConstraint(RectangleConstraint c) {
        if (c == null) {
            throw new IllegalArgumentException("Null 'c' argument.");
        }
        if (c.equals(RectangleConstraint.NONE)) {
            return c;
        }
        double w = c.getWidth();
        Range wr = c.getWidthRange();
        double h = c.getHeight();
        Range hr = c.getHeightRange();
        double ww = trimToContentWidth(w);
        double hh = trimToContentHeight(h);
        Range wwr = trimToContentWidth(wr);
        Range hhr = trimToContentHeight(hr);
        return new RectangleConstraint(
            ww, wwr, c.getWidthConstraintType(), 
            hh, hhr, c.getHeightConstraintType()
        );
    }

    private Range trimToContentWidth(Range r) {
        if (r == null) {
            return null;   
        }
        double lowerBound = 0.0;
        double upperBound = Double.POSITIVE_INFINITY;
        if (r.getLowerBound() > 0.0) {
            lowerBound = trimToContentWidth(r.getLowerBound());   
        }
        if (r.getUpperBound() < Double.POSITIVE_INFINITY) {
            upperBound = trimToContentWidth(r.getUpperBound());
        }
        return new Range(lowerBound, upperBound);
    }
    
    private Range trimToContentHeight(Range r) {
        if (r == null) {
            return null;   
        }
        double lowerBound = 0.0;
        double upperBound = Double.POSITIVE_INFINITY;
        if (r.getLowerBound() > 0.0) {
            lowerBound = trimToContentHeight(r.getLowerBound());   
        }
        if (r.getUpperBound() < Double.POSITIVE_INFINITY) {
            upperBound = trimToContentHeight(r.getUpperBound());
        }
        return new Range(lowerBound, upperBound);
    }
    
    /**
     * Adds the margin, border and padding to the specified content width.
     * 
     * @param contentWidth  the content width.
     * 
     * @return The adjusted width.
     */
    protected double calculateTotalWidth(double contentWidth) {
        double result = contentWidth;
        result = this.padding.extendWidth(result);
        result = this.border.getInsets().extendWidth(result);
        result = this.margin.extendWidth(result);
        return result;
    }

    /**
     * Adds the margin, border and padding to the specified content height.
     * 
     * @param contentHeight  the content height.
     * 
     * @return The adjusted height.
     */
    protected double calculateTotalHeight(double contentHeight) {
        double result = contentHeight;
        result = this.padding.extendHeight(result);
        result = this.border.getInsets().extendHeight(result);
        result = this.margin.extendHeight(result);
        return result;
    }

    /**
     * Reduces the specified area by the amount of space consumed 
     * by the margin.
     * 
     * @param area  the area (<code>null</code> not permitted).
     * 
     * @return The trimmed area.
     */
    protected Rectangle2D trimMargin(Rectangle2D area) {
        // defer argument checking...
        this.margin.trim(area);
        return area;
    }
    
    /**
     * Reduces the specified area by the amount of space consumed 
     * by the border.
     * 
     * @param area  the area (<code>null</code> not permitted).
     * 
     * @return The trimmed area.
     */
    protected Rectangle2D trimBorder(Rectangle2D area) {
        // defer argument checking...
        this.border.getInsets().trim(area);
        return area;
    }

    /**
     * Reduces the specified area by the amount of space consumed 
     * by the padding.
     * 
     * @param area  the area (<code>null</code> not permitted).
     * 
     * @return The trimmed area.
     */
    protected Rectangle2D trimPadding(Rectangle2D area) {
        // defer argument checking...
        this.padding.trim(area);
        return area;
    }

    /**
     * Draws the border around the perimeter of the specified area.
     * 
     * @param g2  the graphics device.
     * @param area  the area.
     */
    protected void drawBorder(Graphics2D g2, Rectangle2D area) {
        this.border.draw(g2, area);
    }
    
    /**
     * Tests this block for equality with an arbitrary object.
     * 
     * @param obj  the object (<code>null</code> permitted).
     * 
     * @return A boolean.
     */
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;   
        }
        if (!(obj instanceof AbstractBlock)) {
            return false;   
        }
        AbstractBlock that = (AbstractBlock) obj;
        if (!this.border.equals(that.border)) {
            return false;   
        }
        if (!this.bounds.equals(that.bounds)) {
            return false;   
        }
        if (!this.margin.equals(that.margin)) {
            return false;   
        }
        if (!this.padding.equals(that.padding)) {
            return false;   
        }
        if (this.height != that.height) {
            return false;   
        }
        if (this.width != that.width) {
            return false;   
        }
        return true;
    }
    
    /**
     * Provides serialization support.
     *
     * @param stream  the output stream.
     *
     * @throws IOException if there is an I/O error.
     */
    private void writeObject(ObjectOutputStream stream) throws IOException {
        stream.defaultWriteObject();
        SerialUtilities.writeShape(this.bounds, stream);
    }

    /**
     * Provides serialization support.
     *
     * @param stream  the input stream.
     *
     * @throws IOException  if there is an I/O error.
     * @throws ClassNotFoundException  if there is a classpath problem.
     */
    private void readObject(ObjectInputStream stream) 
        throws IOException, ClassNotFoundException {
        stream.defaultReadObject();
        this.bounds = (Rectangle2D) SerialUtilities.readShape(stream);
    }

}