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TrayIcon Redraw? [message #666412]

Wed, 20 April 2011 11:24

No real name

Messages: 5
Registered: April 2011

Junior Member

Hi,

I'm trying to write a little program that uses a TrayIcon. I want to change the image there when something happens.

I assign a new image to it though, and the icon doesn't update or redraw. The only way I can get it to do so is to mouse over, which defeats the whole object.

I tried disposing and instantiating a new TrayIcon, that doesn't work either.

This is on Win32 by the way.

Is this a bug? Should I be calling some extra method? (I've tried setVisible as well).

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Re: TrayIcon Redraw? [message #666608 is a reply to message #666412]

Thu, 21 April 2011 10:01

Lakshmi Shanmugam

Messages: 276
Registered: July 2009
Location: India

Senior Member

Hi,

There is no TrayIcon class in SWT, did you mean TrayItem?

Updating the tray item's image works fine for me on Windows XP. Here is an example snippet of TrayItem -> Snippet143.java

I tried to change the image by using this code in the above snippet, and it works fine. Does it work for you?

shell.addListener(SWT.MouseDown, new Listener() {
public void handleEvent(Event event) {
item.setImage(display.getSystemImage(SWT.ICON_ERROR));
}
});

Lakshmi P Shanmugam

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Re: TrayIcon Redraw? [message #666609 is a reply to message #666608]

Thu, 21 April 2011 10:06

No real name

Messages: 5
Registered: April 2011

Junior Member

Yeah, sorry, I meant TrayItem.

In your code, you're changing it from a mouse event on the TrayItem?

Try changing it from a timer or a button press in another window. I'm on XP, and in those cases, it doesn't work.

[Updated on: Thu, 21 April 2011 10:07]

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Re: TrayIcon Redraw? [message #666612 is a reply to message #666609]

Thu, 21 April 2011 10:12

Thomas Schindl

Messages: 6523
Registered: July 2009

Senior Member

Am 21.04.11 12:06, schrieb gareth.foster@thomsonreuters.com:
> Yeah, sorry, I meant TrayItem.
>
> In you're code, you're changing it from a mouse event on the TrayItem?
>
> Try changing it from a timer or a button press in another window. I'm on
> XP, and in those cases, it doesn't work.

Timer? Makes me wonder of you are not syncing with the UI-Thread.

Tom

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Re: TrayIcon Redraw? [message #666621 is a reply to message #666612]

Thu, 21 April 2011 10:52

No real name

Messages: 5
Registered: April 2011

Junior Member

I think I just went part way to solving this by writing a stripped down test case.

Even though the timer fires and changes the value of iTest, the code doesn't get to changing the icon until I mouseover, because it's stuck in the readAndDispatch/sleep methods.

What do I need to do to kick it out of there?

class CMain {

int iTest = 1;

public void test() {

final Display display = Display.getDefault();
Tray tray = display.getSystemTray();
TrayItem trayItem = new TrayItem(tray, SWT.NONE);
trayItem.setImage(display.getSystemImage(SWT.ICON_ERROR));

Timer timer = new Timer();
timer.scheduleAtFixedRate(new TimerTask() {

@Override
public void run() {
++ iTest;
} }, 0, 60 * 1000);

while (true) {
if (!Display.getDefault().readAndDispatch())
Display.getDefault().sleep();

if(iTest % 2 == 0) {
trayItem.setImage(display.getSystemImage(SWT.ICON_INFORMATIO N));
} else {
trayItem.setImage(display.getSystemImage(SWT.ICON_ERROR));
}

}
}

}

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Re: TrayIcon Redraw? [message #666626 is a reply to message #666621]

Thu, 21 April 2011 11:27

No real name

Messages: 5
Registered: April 2011

Junior Member

Solved it, the solution was to use wake(), as talked about half way down this page.

http://book.javanb.com/swt-the-standard-widget-toolkit/ch05l ev1sec6.html

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Re: TrayIcon Redraw? [message #666630 is a reply to message #666621]

Thu, 21 April 2011 11:31

Thomas Schindl

Messages: 6523
Registered: July 2009

Senior Member

Am 21.04.11 12:52, schrieb gareth.foster@thomsonreuters.com:
> I think I just went part way to solving this by writing a stripped down
> test case.
>
> Even though the timer fires and changes the value of iTest, the code
> doesn't get to changing the icon until I mouseover, because it's stuck
> in the readAndDispatch/sleep methods.
>
> What do I need to do to kick it out of there?
>

To make your test code run you'd have to invoke Display.wake() in your
TimerTask but I really don't understand why you you're not doing the
update from withing your TimerTask which makes whole lot more to me:

new TimerTask {
public void run() {
final int i = ++ iTest;
display.syncExec(new Runnable() {
public void run() {
if(i % 2 == 0) {
trayItem.setImage(
display.getSystemImage(SWT.ICON_INFORMATION));
} else {
trayItem.setImage(
display.getSystemImage(SWT.ICON_ERROR));
}
}
});
}
}

Tom

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Re: TrayIcon Redraw? [message #666644 is a reply to message #666630]

Thu, 21 April 2011 12:40

No real name

Messages: 5
Registered: April 2011

Junior Member

I tried doing the update from there, it blew up moaning about accessing SWT widgets from outside the main thread. I thought I'd read this wasn't allowed?

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Re: TrayIcon Redraw? [message #666651 is a reply to message #666644]

Thu, 21 April 2011 12:49

Thomas Schindl

Messages: 6523
Registered: July 2009

Senior Member

That's why you see a display.syncExec() in there which allows you to
sync back from an thread into the UI one.

Tom

Am 21.04.11 14:40, schrieb gareth.foster@thomsonreuters.com:
> I tried doing the update from there, it blew up moaning about accessing
> SWT widgets from outside the main thread. I thought I'd read this wasn't
> allowed?

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Re: TrayIcon Redraw? [message #666652 is a reply to message #666644]

Thu, 21 April 2011 12:50

Thomas Schindl

Messages: 6523
Registered: July 2009

Senior Member

and one more not you can use Display#timerExec so avoid all the thread
syncing stuff.

Am 21.04.11 14:40, schrieb gareth.foster@thomsonreuters.com:
> I tried doing the update from there, it blew up moaning about accessing
> SWT widgets from outside the main thread. I thought I'd read this wasn't
> allowed?

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