e844. setting the location of a tool tip.txt

这里面包含了一百多个JAVA源文件

By default, when a tool tip of a component appears, its northwest corner appears at the same x-coordinate as the cursor and 20 pixels lower than the y-coordinate of the cursor. To change this default location for a component, the getToolTipLocation() method of the component must be overridden. 
    // Set the location of the tool tip such that its nw corner
    // coincides with the nw corner of the button
    JButton button = new JButton("My Button") {
        public Point getToolTipLocation(MouseEvent event) {
            return new Point(0, 0);
        }
    };
    
    // Set the location of the tool tip such that its nw corner
    // coincides with the bottom center of the button
    button = new JButton("My Button") {
        public Point getToolTipLocation(MouseEvent event) {
            return new Point(getWidth()/2, getHeight());
        }
    };
    
    // Use the default tool tip location
    button = new JButton("My Button") {
        public Point getToolTipLocation(MouseEvent event) {
            return null;
        }
    };
    
    // Set the tool tip text
    button.setToolTipText("aString");