textutilities.java

来自「JfreeChart 常用图表例子」· Java 代码 · 共 885 行 · 第 1/3 页

            );
        }
        return bounds;
    }
    
    /**
     * Draws a string such that the specified anchor point is aligned to the 
     * given (x, y) location.
     *
     * @param text  the text.
     * @param g2  the graphics device.
     * @param x  the x coordinate (Java 2D).
     * @param y  the y coordinate (Java 2D).
     * @param anchor  the anchor location.
     * 
     * @return The text bounds (adjusted for the text position).
     */
    public static Rectangle2D drawAlignedString(final String text,
                                                final Graphics2D g2,
                                                final float x,
                                                final float y,
                                                final TextAnchor anchor) {

        final Rectangle2D textBounds = new Rectangle2D.Double();
        final float[] adjust = deriveTextBoundsAnchorOffsets(
            g2, text, anchor, textBounds
        );
        // adjust text bounds to match string position
        textBounds.setRect(
            x + adjust[0], y + adjust[1] + adjust[2], 
            textBounds.getWidth(), textBounds.getHeight()
        );
        g2.drawString(text, x + adjust[0], y + adjust[1]);
        return textBounds;

    }

    /**
     * A utility method that calculates the anchor offsets for a string.  
     * Normally, the (x, y) coordinate for drawing text is a point on the 
     * baseline at the left of the text string.  If you add these offsets to 
     * (x, y) and draw the string, then the anchor point should coincide with 
     * the (x, y) point.
     *
     * @param g2  the graphics device (not <code>null</code>).
     * @param text  the text.
     * @param anchor  the anchor point.
     * @param textBounds  the text bounds (if not <code>null</code>, this 
     *                    object will be updated by this method to match the 
     *                    string bounds).
     * 
     * @return  The offsets.
     */
    private static float[] deriveTextBoundsAnchorOffsets(final Graphics2D g2, 
            final String text, final TextAnchor anchor,
            final Rectangle2D textBounds) {

        final float[] result = new float[3];
        final FontRenderContext frc = g2.getFontRenderContext();
        final Font f = g2.getFont();
        final FontMetrics fm = g2.getFontMetrics(f);
        final Rectangle2D bounds = TextUtilities.getTextBounds(text, g2, fm);
        final LineMetrics metrics = f.getLineMetrics(text, frc);
        final float ascent = metrics.getAscent();
        result[2] = - ascent;
        final float halfAscent = ascent / 2.0f;
        final float descent = metrics.getDescent();
        final float leading = metrics.getLeading();
        float xAdj = 0.0f;
        float yAdj = 0.0f;

        if (anchor == TextAnchor.TOP_CENTER
                || anchor == TextAnchor.CENTER
                || anchor == TextAnchor.BOTTOM_CENTER
                || anchor == TextAnchor.BASELINE_CENTER
                || anchor == TextAnchor.HALF_ASCENT_CENTER) {
                    
            xAdj = (float) -bounds.getWidth() / 2.0f;
            
        }
        else if (anchor == TextAnchor.TOP_RIGHT
                || anchor == TextAnchor.CENTER_RIGHT
                || anchor == TextAnchor.BOTTOM_RIGHT
                || anchor == TextAnchor.BASELINE_RIGHT
                || anchor == TextAnchor.HALF_ASCENT_RIGHT) {
                    
            xAdj = (float) -bounds.getWidth();
            
        }

        if (anchor == TextAnchor.TOP_LEFT
                || anchor == TextAnchor.TOP_CENTER
                || anchor == TextAnchor.TOP_RIGHT) {
                    
            yAdj = -descent - leading + (float) bounds.getHeight();
            
        }
        else if (anchor == TextAnchor.HALF_ASCENT_LEFT
                || anchor == TextAnchor.HALF_ASCENT_CENTER
                || anchor == TextAnchor.HALF_ASCENT_RIGHT) {
                    
            yAdj = halfAscent;
            
        }
        else if (anchor == TextAnchor.CENTER_LEFT
                || anchor == TextAnchor.CENTER
                || anchor == TextAnchor.CENTER_RIGHT) {
                    
            yAdj = -descent - leading + (float) (bounds.getHeight() / 2.0);
            
        }
        else if (anchor == TextAnchor.BASELINE_LEFT
                || anchor == TextAnchor.BASELINE_CENTER
                || anchor == TextAnchor.BASELINE_RIGHT) {
                    
            yAdj = 0.0f;
            
        }
        else if (anchor == TextAnchor.BOTTOM_LEFT
                || anchor == TextAnchor.BOTTOM_CENTER
                || anchor == TextAnchor.BOTTOM_RIGHT) {
                    
            yAdj = -metrics.getDescent() - metrics.getLeading();
            
        }
        if (textBounds != null) {
            textBounds.setRect(bounds);   
        }
        result[0] = xAdj;
        result[1] = yAdj;
        return result;

    }

    /** 
     * A flag that controls whether or not the rotated string workaround is 
     * used. 
     */
    private static boolean useDrawRotatedStringWorkaround = true;

    /**
     * Sets the flag that controls whether or not the rotated string 
     * workaround is used.
     *
     * @param use  the new flag value.
     */
    public static void setUseDrawRotatedStringWorkaround(final boolean use) {
        useDrawRotatedStringWorkaround = use;
    }

    /**
     * A utility method for drawing rotated text.
     * <P>
     * A common rotation is -Math.PI/2 which draws text 'vertically' (with the 
     * top of the characters on the left).
     *
     * @param text  the text.
     * @param g2  the graphics device.
     * @param angle  the angle of the (clockwise) rotation (in radians).
     * @param x  the x-coordinate.
     * @param y  the y-coordinate.
     */
    public static void drawRotatedString(final String text,
                                         final Graphics2D g2,
                                         final double angle,
                                         final float x,
                                         final float y) {
        drawRotatedString(text, g2, x, y, angle, x, y);
    }

    /**
     * A utility method for drawing rotated text.
     * <P>
     * A common rotation is -Math.PI/2 which draws text 'vertically' (with the 
     * top of the characters on the left).
     *
     * @param text  the text.
     * @param g2  the graphics device.
     * @param textX  the x-coordinate for the text (before rotation).
     * @param textY  the y-coordinate for the text (before rotation).
     * @param angle  the angle of the (clockwise) rotation (in radians).
     * @param rotateX  the point about which the text is rotated.
     * @param rotateY  the point about which the text is rotated.
     */
    public static void drawRotatedString(final String text,
                                         final Graphics2D g2,
                                         final float textX,
                                         final float textY,
                                         final double angle,
                                         final float rotateX,
                                         final float rotateY) {

        if ((text == null) || (text.equals(""))) {
            return;
        }

        final AffineTransform saved = g2.getTransform();

        // apply the rotation...
        final AffineTransform rotate = AffineTransform.getRotateInstance(
            angle, rotateX, rotateY
        );
        g2.transform(rotate);

        if (useDrawRotatedStringWorkaround) {
            // workaround for JDC bug ID 4312117 and others...
            final TextLayout tl = new TextLayout(
                text, g2.getFont(), g2.getFontRenderContext()
            );
            tl.draw(g2, textX, textY);
        }
        else {
            // replaces this code...
            g2.drawString(text, textX, textY);
        }
        g2.setTransform(saved);

    }

    /**
     * Draws a string that is aligned by one anchor point and rotated about 
     * another anchor point.
     *
     * @param text  the text.
     * @param g2  the graphics device.
     * @param x  the x-coordinate for positioning the text.
     * @param y  the y-coordinate for positioning the text.
     * @param textAnchor  the text anchor.
     * @param angle  the rotation angle.
     * @param rotationX  the x-coordinate for the rotation anchor point.
     * @param rotationY  the y-coordinate for the rotation anchor point.
     */
    public static void drawRotatedString(final String text,
                                         final Graphics2D g2,
                                         final float x,
                                         final float y,
                                         final TextAnchor textAnchor,
                                         final double angle,
                                         final float rotationX,
                                         final float rotationY) {

        if (text == null || text.equals("")) {
            return;
        }
        final float[] textAdj = deriveTextBoundsAnchorOffsets(
            g2, text, textAnchor
        );
        drawRotatedString(
            text, g2, x + textAdj[0], y + textAdj[1],
            angle, rotationX, rotationY
        );

    }

    /**
     * Draws a string that is aligned by one anchor point and rotated about 
     * another anchor point.
     *
     * @param text  the text.
     * @param g2  the graphics device.
     * @param x  the x-coordinate for positioning the text.
     * @param y  the y-coordinate for positioning the text.
     * @param textAnchor  the text anchor.
     * @param angle  the rotation angle (in radians).
     * @param rotationAnchor  the rotation anchor.
     */
    public static void drawRotatedString(final String text,
                                         final Graphics2D g2,
                                         final float x,
                                         final float y,
                                         final TextAnchor textAnchor,
                                         final double angle,
                                         final TextAnchor rotationAnchor) {

        if (text == null || text.equals("")) {
            return;
        }
        final float[] textAdj = deriveTextBoundsAnchorOffsets(
            g2, text, textAnchor
        );
        final float[] rotateAdj = deriveRotationAnchorOffsets(
            g2, text, rotationAnchor
        );
        drawRotatedString(
            text, g2, x + textAdj[0], y + textAdj[1],
            angle, x + textAdj[0] + rotateAdj[0], y + textAdj[1] + rotateAdj[1]
        );

    }

    /**
     * Returns a shape that represents the bounds of the string after the 
     * specified rotation has been applied.
     * 
     * @param text  the text (<code>null</code> permitted).