framedtext.java

书籍"Java_面向事件编程"的附带光盘代码

import objectdraw.*;
import java.awt.*;

// A FramedText object displays a specified text message on a
// background framed by a distinct border.
public class FramedText extends FramedDisplay {
    
    // Colors used for the text
    private static final Color TEXTCOLOR = Color.gray;
    private static final Color HIGHLIGHTCOLOR = Color.red;
    
    protected Text message;            // The message displayed
    
    // Create a FramedText object displaying the text 'contents'
    // at the position and with the dimensions specified.
    public FramedText( String contents, double x, double y,
                       double width, double height,
                       DrawingCanvas canvas) {
        
        // construct the frame
        super( x, y, width, height, canvas);
        
        // Construct and appropriately position the message
        message = new Text ( contents, x, y, canvas);
        message.setColor( TEXTCOLOR );
        positionContents();
    }

    // Position the message to center it in the frame
    private void positionContents() {
        message.moveTo( displayLeft(), displayTop() );
        message.move( (displayWidth()-message.getWidth())/2,
                      (displayHeight()-message.getHeight()) /2 );
    }        
    
    // Change the font size used
    public void setTextSize( int size) {
        message.setFontSize( size );
        positionContents();
    }
    
    // Highlight the display by changing the text color
    public void highlight() {
        message.setColor( HIGHLIGHTCOLOR );
    }
    
    // Restore the standard text color
    public void unHighlight() {
        message.setColor( TEXTCOLOR );
    }
    
}