This week's giveaway is in the Android forum.
We're giving away four copies of Android Security Essentials Live Lessons and have Godfrey Nolan on-line!
See this thread for details.
The moose likes Applets and the fly likes Applet focus solution Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login


Win a copy of Android Security Essentials Live Lessons this week in the Android forum!
JavaRanch » Java Forums » Java » Applets
Bookmark "Applet focus solution" Watch "Applet focus solution" New topic
Author

Applet focus solution

Darren Brooks
Ranch Hand

Joined: Dec 29, 2005
Posts: 31
I conducted a fruitless search for solutions to getting my applet to appear in a web page with focus (so the user doesn't first have to click on it to interact with it). Many others seem to have searched in vain, as well, so I thought I'd contribute my two bytes on this subject.

One post on JavaRanch suggested requestFocus(), yet this only works once the applet is active. Below is how I used this head start (if you will ;] ) to accomplish giving an applet focus.

Here is a solution that has worked for me (I would appreciate your thoughts):

First, my class extends Applet and implements Runnable, so run() has the following statement inside the WHILE loop:



As mentioned above, focusApplet() is called by a looping thread instance in run() (e.g., a "timer"). This method is called repeatedly until hasFocus() == true. hasFocus() is an Applet method. One cannot set the focus on an Applet until is has become active (e.g., isActive() == true).

I have added some variables to check how long it takes for my Applet to become active; uncomment the System.out.println call and use a command line to open the applet to see the result (e.g., appletviewer applet.html).

By the way, Calling [if (!hasFocus()) focusApplet()] logic from inside run() is 8x faster than checking hasFocus() inside focusApplet() itself. The event seems to take literally nanoseconds to occur!

I made the method below synchronized - this seems to prevent an error when the applet shuts down (race condition? - I haven't really checked into it). It makes sense synchronizing the method. I hope some java gurus will explain if this is not appropriate.

Daia Yum
Greenhorn

Joined: Mar 23, 2009
Posts: 19

First, my class extends Applet and implements Runnable, so run() has the following statement inside the WHILE loop:


What is the while loop here.
I want to call a method when I press S key in the keyboard without using mouse.
But my applet is not getting the focus.
My Applet code is here.



Please help me out. Is anything wrong in my code???


Daia
 
I agree. Here's the link: http://aspose.com/file-tools
 
subject: Applet focus solution
 
Similar Threads
getting the index of the closest value in an array that is sorted in reverse order
requestFocusInWindow() doesnt work
Focus problem
Focus problems in an interior JTextField
Is this a good approach?