Develop Reference

Drawing animation in a Nattable OverlayPainter

I am trying to render a loading animation on top of a nattable. I use the OverLayPainter mechanism to draw a "glasspane" and some text on top of the table, and this works perfect:
public class MessageOverlay
implements IOverlayPainter {
....
#Override
public void paintOverlay(final GC gc, final ILayer layer) {
this.currentGC = gc;
this.currentLayer = layer;
if (visible) {
currentGC.setAlpha(200);
currentGC.fillRectangle(0, 0, currentLayer.getWidth(), currentLayer
.getHeight());
drawMessage();
if (withLoadingAnimation) {
showAnimation = true;
}
} else {
showAnimation = false;
}
}
}
However, the paintOverlay method is not called regularely but rather everytime the table changes.
To be able to display a smoothe animation, I added a new thread
final Thread animatorThread = new Thread(new Runnable() {
#Override
public void run() {
while (!Thread.interrupted()) {
try {
Thread.sleep(1000 / fps);
} catch (final InterruptedException e) {
break;
}
display.asyncExec(new Runnable() {
#Override
public void run() {
if (showAnimation && !currentGC.isDisposed()) {
final Image currentImage = getNextImage();
final int posX = currentGC.getClipping().width / 2
- currentImage.getBounds().width;
final int posY = currentGC.getClipping().height / 2
- currentImage.getBounds().height;
currentGC.drawImage(currentImage, posX, posY);
}
}
});
}
}
});
animatorThread.start();
As you can see it tries to access the graphics context this.currentGC set in the paintOverlay method. My problem is, that currentGC within the animatorThread is always disposed.
How can I a.) ensure that the context is not disposed in the thread or b.) solve this in an alternative way?
Thanks for the help.

You could try to create a new GC with the current NatTable instance and if needed pass the config from the passed in GC instance. Then you are in charge of disposing the GC instance and should not have the risk of a disposed GC outside your thread.
A simple example could look like the following snippet that simply shows the pane for 1000ms and then removes it again. You need of course to change the logic to be more dynamic with regards to your loading operation then:
AtomicBoolean paneThreadStarted = new AtomicBoolean(false);
...
natTable.addOverlayPainter(new IOverlayPainter() {
#Override
public void paintOverlay(GC gc, ILayer layer) {
if (this.paneThreadStarted.compareAndSet(false, true)) {
Display.getDefault().asyncExec(new Runnable() {
#Override
public void run() {
GC currentGC = new GC(natTable);
currentGC.setForeground(GUIHelper.COLOR_WHITE);
currentGC.setBackground(GUIHelper.COLOR_BLACK);
currentGC.setAlpha(200);
currentGC.fillRectangle(0, 0, layer.getWidth(), layer.getHeight());
String load = "Loading data ...";
Point textExtent = currentGC.textExtent(load);
currentGC.drawText(load,
layer.getWidth() / 2 - textExtent.x / 2,
layer.getHeight() / 2 - textExtent.y / 2,
true);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
currentGC.dispose();
natTable.redraw();
}
});
}
}
});
This way you are able to show the pane again by changing the AtomicBoolean from the outside:
Button showPaneButton = new Button(buttonPanel, SWT.PUSH);
showPaneButton.setText("Show Pane");
showPaneButton.addSelectionListener(new SelectionAdapter() {
#Override
public void widgetSelected(SelectionEvent e) {
this.paneThreadStarted.set(false);
natTable.redraw();
}
});

Thread is blocking execution

I have a simple class which has a thread in it. Whenever user clicks on a button, I want to run the thread. Everything works great, except that whenever I click on the button while the thread is already running, my onTouch executes only after the thread has finished executing.
..
MyTouchAnimatorClass touchAnimatorClass = new MyTouchAnimatorClass();
view.setOnClickListener( new View.OnClickListener()
{
#Override
public void onClick( View view )
{
touchAnimatorClass.onTouch();
}
});
..
And my class with the thread:
Class MyTouchAnimatorClass
{
private boolean threadRunning = false;
public void onTouch() // <-- only executes AFTER the thread is complete
{
if( !threadRunning )
animate();
}
private void animate()
{
threadRunning = true;
Runnable r = new Runnable()
{
#Override
public void run()
{
activity.runOnUiThread(new Runnable()
{
#Override
public void run()
{
int i=0;
boolean doBreak = false;
while( true )
{
i+=1;
if( i == 100 )
break;
}
}
}
}
}
new Thread( r ).start();
threadRunning = false;
}
}
I can't understand why this is happening, isn't the Runnable running in its own thread? Any suggestions please? Thank you!
EDIT:
I tried using
new Thread( r ).start();
Instead of:
r.run();
But unfortunately the same problem persists:
If I click the button the second time (while the thread is still running from the first click), it should execute onTouch, but shouldn't execute animate() since it is still running from the previous click.
What actually happens: The touch is non response until the thread from the first click has finished executing. Then onTouch triggers (even though I pressed it few seconds ago) and a new thread is started again.
If I press the button 10 times quickly, it will do 10 loops in a row, instead of doing one and blocking the others.

activity.runOnUiThread is asking the Android system to run this Runnable on the UI thread.
You can rather do new Thread(r).start();
Like this:
private void animate()
{
threadRunning = true;
//Define the work as a Runnable
Runnable r = new Runnable()
{
#Override
public void run()
{
int i=0;
//boolean doBreak = false; //Not used
while( true )
{
i+=1;
if( i == 100 )
break;
}
threadRunning = false; //Just before leaving
}
}
//Give that work to a new thread and start the thread
new Thread(r).run();
}

Runnable isn't a thread, is just a set of instructions to be executed in a thread
in order to achieve what you want you need to do
new Thread(r).start(); at end of your code

Java Robot clicking is going at 70 clicks per second cannot figure out the math / what is going wrong

volatile private boolean mouseDown = false;
private int max = 0;
private int min = 0;
private Robot robot;
public MouseClickListener()
{
try
{
robot = new Robot();
} catch (AWTException e)
{
e.printStackTrace();
}
}
#Override
public void nativeMouseClicked(NativeMouseEvent nativeMouseEvent)
{
}
#Override
public void nativeMousePressed(NativeMouseEvent nativeMouseEvent)
{
if (nativeMouseEvent.getButton() == NativeMouseEvent.BUTTON1)
{
max = Native.get().getFrame().getCps().getValue() + Native.get().getFrame().getDev().getValue();
min = Native.get().getFrame().getCps().getValue() - Native.get().getFrame().getDev().getValue();
mouseDown = true;
initThread();
}
}
#Override
public void nativeMouseReleased(NativeMouseEvent nativeMouseEvent)
{
if (nativeMouseEvent.getButton() == NativeMouseEvent.BUTTON1)
{
mouseDown = false;
}
}
Hi there, so basically I'm trying to make an auto clicker which clicks at values to a JSlider (a random value between say 9 and 13, just for example).
So on mouse click the initThread method is called, and the clicks per second is worked out ( a random number between the JSlider value, which is from a diff. class), and then from that, I click and then sleep the thread for 1 / randomNum (in seconds) so that it clicks that many times per second.
For some reason it's clicking at like 200cps and lagging my computer out. Does anyone see any problem with my code?
Thanks.
NEW CODE FOR CLICKER;
public class ClickMethod implements Runnable
{
#Override
public void run()
{
System.out.println("STARTED");
do
{
System.out.println("RUNNING");
Random r = new Random();
int random = r.nextInt((max - min) + 1) + min;
robot.mousePress(BUTTON1_MASK);
robot.mouseRelease(BUTTON1_MASK);
try
{
Thread.sleep(1000 / random);
} catch (InterruptedException e)
{
e.printStackTrace();
}
} while (mouseDown);
}
}
For some reason this only runs once and then isn't called when the mouseDown variable changes.

If this is intended to be clicked by you every so often then it creates numerous threads which all click away
public void nativeMousePressed(NativeMouseEvent nativeMouseEvent)
{
if (nativeMouseEvent.getButton() == NativeMouseEvent.BUTTON1)
{
max = Native.get().getFrame().getCps().getValue() + Native.get().getFrame().getDev().getValue();
min = Native.get().getFrame().getCps().getValue() - Native.get().getFrame().getDev().getValue();
mouseDown = true;
initThread();
}
}
You need to remove initThread() from there and call it once somewhere , e.g., in the constructor.

Pause Android app until button press

I have two methods: go() and stop(), and a for loop looping through these methods 3 times. go() activates automatically when the loop starts and stop() will only activate once a button is pressed 3 times:
private static int buttonPress;
for (int i = 0; i < 3, i++) {
go();
do {} while(pressCount < 4);
stop();
}
Whenever the button the pressed, pressCount is incremented by 1:
public void button(View v) {
pressCount++;
}
The problem is that with this setup, when the do while loop launches, the app freezes and crashes.
Is there any way to fix this while still having the go() activate before stop(), having stop() activate after pressCount is greater than 3, and looping through 3 times?
Thanks

you cannot block the main thread for more than 5 seconds if that happens then an anr (Application not responding) dialog pops up.

You cannot pause main thread, the app freezes.
private int loopCount = 0;
private int pressCount = 0;
public void button(View v) { /* Runs when button is clicked */
if (loopCount < 4){
pressCount++;
if (pressCount == 3){
pressCount = 0;
loopCount++;
stop();
}
}
}
This code runs stop() when the button is pressed three times, but runs that only three times. (After 9 presses nothing happens)

try this
private boolean isStop = true;
private int buttonPressedCount = 0;
private void goOrStop() {
if(isStop) {
go();
isStop = false;
} else {
stopIfCan(); // :)
}
}
private void stopIfCan() {
if(buttonPressedCount >= 3 ) {
buttonPressedCount = 0;
isStop = false;
stop();
}
}
public void button(View v) {
buttonPressedCount++;
}

How to use JButtons to Start and Pause SwingWorker thread

I'm trying to learn Threads in Swing.
I have a Frame with a JProgressBar (progress), five JButtons (Start, Suspend, Resume, Cancel, Close), and a JLabel (label1).
The frame opens. Only Start is enabled. Start calls my class Progressor:
Updated Again Once and For All
Progressor progressor; //declared as class variable, initialized new in constructor and again in overridden done method
Here's the ButtonListener class:
public class ButtonListener implements ActionListener{
public void actionPerformed(ActionEvent e)
{
if (e.getSource() == jbStart) {
progressor.execute();
label1.setText("Progressing ...");
jbCancel.setEnabled(true);
jbResume.setEnabled(true);
jbSuspend.setEnabled(true);
jbClose.setEnabled(true);
}
if(e.getSource() == jbCancel) {
progressor.cancel(true);
label1.setText("Progress Canceled");
}
if (e.getSource() == jbSuspend) {
label1.setText(progressor.suspendProgress());
}
if (e.getSource() == jbResume) {
label1.setText(progressor.resumeProgress());
}
if (e.getSource() == jbClose) {
dispose();
}
}
}//buttonlistener
Here's the SwingWorker class:
public class Progressor extends SwingWorker<Void, Integer> {
private volatile boolean suspend = false;
private Object lock = new Object();
#Override
protected Void doInBackground() {
for (int i = 0; i <= 10; i++) {
checkForSuspend();
try {
Thread.sleep(1000);
}
catch (InterruptedException e) {
}
publish(i);
}
return null;
}
#Override
protected void process(List<Integer> list) {
int value = list.get(list.size() - 1);
progress.setValue(value);
}
public void checkForSuspend() {
synchronized (lock) {
while (suspend) {
try {
lock.wait();
} catch (InterruptedException ie){
}
}
}
}//checkForSuspend
#Override
protected void done() {
label1.setText("All Done. Press close to exit");
progressor = new Progressor();
}
public synchronized String suspendProgress() {
suspend = true;
return "Progress suspended ...";
}
public synchronized String resumeProgress() {
synchronized (lock) {
suspend = false;
lock.notify();
return "Progress resumed ...";
}
}
}//Progressor class
Everything works except the cancel doesn't doesn't actually cancel the thread (the progress bar continues).
Should I suspend it before canceling?

This How to Pause and Resume a Thread in Java from another Thread question looks very similar to yours and has some nice examples in the answers.
As for your own code and why it does not work:
You create a new progressor on every click. You should be using and controlling one, instead of creating new ones every time.
When suspending your progressor finishes work instead of suspending. As the above question states - you should be looking at the flag at some points of your computation and acting on it. Example:
while (!cancel) {
if (!suspended) {
for (int i = 1; i <= 10; i++) {
Thread.sleep(1000);
publish(i);
}
}
}
The above code will suspend when it next reaches 10 (unless you resumed it before that), and finish when you press cancel (Cancel needs to be added as an extra flag in the obvious manner).

Your thread should run inside a while loop that looks for a boolean to change value from another object, then simply change the state with setPause(true/false) when you click the button:
while(true){
if(object_everyone_can_reference.getPause()){
Thread.sleep(1000);
}
}