在小程序上仅绘制一次字符串

Question

New in Java and might be repeated question.

Using full screen applet without title bar to render images on ever 10 millisecond time interval with help of paint method. At the same time I want specific text to be displayed on applet screen at any position.

Since images are dynamic hence I am rendering on 10 millisecond but text is fix and not going to change in whole life of applet.

Now concern is, if I draw text in paint method then its burden on paint method to draw image and text on every 10 millisecond time.

public void paint(Graphics  g) 
{   
    if(img != null)
    {
        g.drawImage(img, 0, 0, null);   
        g.drawString("Hey there!", 0, 0); //Additional load
    }           
}   

Cannot place text on title bar too.

Is it possible to draw text at once and rendered images frequently?

Answer 1

If you want to only draw the text once, then I would recommend having a boolean variable outside your paint method:

boolean drawn = true;
public void paint(Graphics g){
    if(drawn) g.drawString(...);
}

The problem with this is that, if you have any moving pixels or objects, (change position each frame) or simply anything that's supposed to disappear, you'll have to write a lot more to erase it. It's simply more readable to layer paint commands on top of each other, and can be edited and created more easily.

Answer 2

public void paint(Graphics  g) 
{ 

Should instead be:

public void paint(Graphics  g) 
{ 
     super.paint(g); // paint the background, borders etc.

So given doing that will erase the previously drawn text, the answer to your question is - no.

BTW - look up 'premature optimization'.