equationdisplay.java

JAVA图形特效,详细介绍SWING等的效果开发

    private void drawEquations(Graphics2D g2) {
        for (DrawableEquation drawable: equations) {
            g2.setColor(drawable.getColor());
            drawEquation(g2, drawable.getEquation());
        }
    }

    private void drawEquation(Graphics2D g2, AbstractEquation equation) {
        float x = 0.0f;
        float y = (float) yPositionToPixel(equation.compute(xPixelToPosition(0.0)));
        
        GeneralPath path = new GeneralPath();
        path.moveTo(x, y);
        
        for (x = 0.0f; x < getWidth(); x += 1.0f) {
            double position = xPixelToPosition(x);
            y = (float) yPositionToPixel(equation.compute(position));
            path.lineTo(x, y);
        }
        
        g2.draw(path);
    }

    private void drawGrid(Graphics2D g2) {
        Stroke stroke = g2.getStroke();

        drawVerticalGrid(g2);
        drawHorizontalGrid(g2);

        if (drawText) {
            drawVerticalLabels(g2);
            drawHorizontalLabels(g2);
        }
        
        g2.setStroke(stroke);
    }
    
    private void drawHorizontalLabels(Graphics2D g2) {
        double axisV = xPositionToPixel(originX);

        g2.setColor(COLOR_AXIS);
        for (double y = originY + majorY; y < maxY + majorY; y += majorY) {
            int position = (int) yPositionToPixel(y);
            g2.drawString(formatter.format(y), (int) axisV + 5, position);
        }
        
        for (double y = originY - majorY; y > minY - majorY; y -= majorY) {
            int position = (int) yPositionToPixel(y);
            g2.drawString(formatter.format(y), (int) axisV + 5, position);
        }
    }
    
    private void drawHorizontalGrid(Graphics2D g2) {
        double minorSpacing = majorY / minorY;
        double axisV = xPositionToPixel(originX);
        
        Stroke gridStroke = new BasicStroke(STROKE_GRID);
        Stroke axisStroke = new BasicStroke(STROKE_AXIS);
        
        for (double y = originY + majorY; y < maxY + majorY; y += majorY) {
            g2.setStroke(gridStroke);
            g2.setColor(COLOR_MINOR_GRID);
            for (int i = 0; i < minorY; i++) {
                int position = (int) yPositionToPixel(y - i * minorSpacing);
                g2.drawLine(0, position, getWidth(), position);    
            }

            int position = (int) yPositionToPixel(y);
            g2.setColor(COLOR_MAJOR_GRID);
            g2.drawLine(0, position, getWidth(), position);
            
            g2.setStroke(axisStroke);
            g2.setColor(COLOR_AXIS);
            g2.drawLine((int) axisV - 3, position, (int) axisV + 3, position);
        }

        for (double y = originY - majorY; y > minY - majorY; y -= majorY) {
            g2.setStroke(gridStroke);
            g2.setColor(COLOR_MINOR_GRID);
            for (int i = 0; i < minorY; i++) {
                int position = (int) yPositionToPixel(y + i * minorSpacing);
                g2.drawLine(0, position, getWidth(), position);    
            }

            int position = (int) yPositionToPixel(y);
            g2.setColor(COLOR_MAJOR_GRID);
            g2.drawLine(0, position, getWidth(), position);
            
            g2.setStroke(axisStroke);
            g2.setColor(COLOR_AXIS);
            g2.drawLine((int) axisV - 3, position, (int) axisV + 3, position);
        }
    }

    private void drawVerticalLabels(Graphics2D g2) {
        double axisH = yPositionToPixel(originY);
        FontMetrics metrics = g2.getFontMetrics();
        
        g2.setColor(COLOR_AXIS);

        for (double x = originX + majorX; x < maxX + majorX; x += majorX) {
            int position = (int) xPositionToPixel(x);
            g2.drawString(formatter.format(x), position, (int) axisH + metrics.getHeight());
        }

        for (double x = originX - majorX; x > minX - majorX; x -= majorX) {
            int position = (int) xPositionToPixel(x);
            g2.drawString(formatter.format(x), position, (int) axisH + metrics.getHeight());
        }
    }
    
    private void drawVerticalGrid(Graphics2D g2) {
        double minorSpacing = majorX / minorX;
        double axisH = yPositionToPixel(originY);
        
        Stroke gridStroke = new BasicStroke(STROKE_GRID);
        Stroke axisStroke = new BasicStroke(STROKE_AXIS);
        
        for (double x = originX + majorX; x < maxX + majorX; x += majorX) {
            g2.setStroke(gridStroke);
            g2.setColor(COLOR_MINOR_GRID);
            for (int i = 0; i < minorX; i++) {
                int position = (int) xPositionToPixel(x - i * minorSpacing);
                g2.drawLine(position, 0, position, getHeight());    
            }

            int position = (int) xPositionToPixel(x);
            g2.setColor(COLOR_MAJOR_GRID);
            g2.drawLine(position, 0, position, getHeight());

            g2.setStroke(axisStroke);
            g2.setColor(COLOR_AXIS);
            g2.drawLine(position, (int) axisH - 3, position, (int) axisH + 3);
        }

        for (double x = originX - majorX; x > minX - majorX; x -= majorX) {
            g2.setStroke(gridStroke);
            g2.setColor(COLOR_MINOR_GRID);
            for (int i = 0; i < minorX; i++) {
                int position = (int) xPositionToPixel(x + i * minorSpacing);
                g2.drawLine(position, 0, position, getHeight());    
            }

            int position = (int) xPositionToPixel(x);
            g2.setColor(COLOR_MAJOR_GRID);
            g2.drawLine(position, 0, position, getHeight());
            
            g2.setStroke(axisStroke);
            g2.setColor(COLOR_AXIS);
            g2.drawLine(position, (int) axisH - 3, position, (int) axisH + 3);
        }
    }

    private void drawAxis(Graphics2D g2) {
        double axisH = yPositionToPixel(originY);
        double axisV = xPositionToPixel(originX);
        
        g2.setColor(COLOR_AXIS);
        Stroke stroke = g2.getStroke();
        g2.setStroke(new BasicStroke(STROKE_AXIS));
        
        g2.drawLine(0, (int) axisH, getWidth(), (int) axisH);
        g2.drawLine((int) axisV, 0, (int) axisV, getHeight());
        
        FontMetrics metrics = g2.getFontMetrics();
        g2.drawString(formatter.format(0.0), (int) axisV + 5, (int) axisH + metrics.getHeight());
        
        g2.setStroke(stroke);
    }

    protected void setupGraphics(Graphics2D g2) {
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
    }

    protected void paintBackground(Graphics2D g2) {
        g2.setColor(COLOR_BACKGROUND);
        g2.fill(g2.getClipBounds());
    }

    private class DrawableEquation {
        private AbstractEquation equation;
        private Color color;

        DrawableEquation(AbstractEquation equation, Color color) {
            this.equation = equation;
            this.color = color;
        }
        
        AbstractEquation getEquation() {
            return equation;
        }
        
        Color getColor() {
            return color;
        }
    }
    
    private class ZoomHandler implements MouseWheelListener {
        public void mouseWheelMoved(MouseWheelEvent e) {
            double distanceX = maxX - minX;
            double distanceY = maxY - minY;
            
            double cursorX = minX + distanceX / 2.0;
            double cursorY = minY + distanceY / 2.0;
            
            int rotation = e.getWheelRotation();
            if (rotation < 0) {
                distanceX /= COEFF_ZOOM;
                distanceY /= COEFF_ZOOM;
            } else {
                distanceX *= COEFF_ZOOM;
                distanceY *= COEFF_ZOOM;
            }
            
            minX = cursorX - distanceX / 2.0;
            maxX = cursorX + distanceX / 2.0;
            minY = cursorY - distanceY / 2.0;
            maxY = cursorY + distanceY / 2.0;

            repaint();
        }
    }
    
    private class PanHandler extends MouseAdapter {
        @Override
        public void mousePressed(MouseEvent e) {
            dragStart = e.getPoint();
        }
    }

    private class PanMotionHandler extends MouseMotionAdapter {
        @Override
        public void mouseDragged(MouseEvent e) {
            Point dragEnd = e.getPoint();

            double distance = xPixelToPosition(dragEnd.getX()) -
                              xPixelToPosition(dragStart.getX());
            minX -= distance;
            maxX -= distance;

            distance = yPixelToPosition(dragEnd.getY()) -
                       yPixelToPosition(dragStart.getY());
            minY -= distance;
            maxY -= distance;
            
            repaint();
            dragStart = dragEnd;
        }
    }
}