Develop Reference

Javafx - Bounds are zero until seen

In an attempt to fix a problem with printing within the margins, I'm trying to scale my forms so that they'd shrink to the size of the paper it will be printed to.
Inside Printable.java that extends VBox
public void scaleToFit(){
double maxWidth = 497.0;
this.requestLayout();
double width = this.getWidth();
if(width > maxWidth){
double widthFrac = maxWidth / width;
this.setScaleX(widthFrac);
}
System.out.println(this.getWidth());
//edited out same process for height
}
Printable will be kept in a HashMap data.table. When my printing window is loaded I run scaleToFit for each of them. main is a ScrollPane.
Inside ModPrintCycle.java that extends VBox
//inside constructor
main.sceneProperty().addListener(new ChangeListener<Scene>(){
#Override
public void changed(ObservableValue<? extends Scene> observable, Scene oldValue, Scene newValue) {
System.out.println("new Scene");
newValue.windowProperty().addListener(new ChangeListener<Window>(){
public void changed(ObservableValue<? extends Window> arg0, Window arg1, Window arg2) {
System.out.println("new Window");
arg2.setOnShown(new EventHandler<WindowEvent>(){
#Override
public void handle(WindowEvent event) {
Platform.runLater(new Runnable(){
#Override
public void run() {
System.out.println(event.toString());
lookingAt = data.tables.size();
while(lookingAt-1 >= 0 ){
showNext(-1);
}
}
});
}
});
}
});
}
});
Just for this example, I also added scaleToFit() in the button that changes between these Printables. [EDIT: Added the scripts that explicitly show the use of scaleToFit()] Note that data.tables is a HashMap containing the Printables.
Inside ModPrintCycle.java continuation
private void showNext(int move){
boolean k = false;
if(move > 0 && lookingAt+move < data.tables.size()){
k = true;
}
else if(move < 0 && lookingAt+move >=0){
k = true;
}
if(k){
lookingAt+= move;
}
show();
}
private void show(){
if(data.tables.size() > 0){
if(lookingAt >= 0 && lookingAt < data.tables.size()){
//tableOrder is an ArrayList<String> for the arrangement of data.tables
if(tableOrder.size() > 0){
Printable pt = data.tables.get(tableOrder.get(lookingAt));
main.setContent(pt);
pt.scaleToFit();
}
}
else{
if(lookingAt < 0){
lookingAt = 0;
show();
}
else if(lookingAt >= data.tables.size()){
lookingAt = data.tables.size()-1;
show();
}
}
txtStatus.setText((lookingAt+1) + " / " + data.tables.size());
}else{
main.setContent(null);
txtStatus.setText("Empty");
}
}
public void printAll(ArrayList<String> pageList){
//PrinterJob pj is global
//conditions and try declarations
pj = PrinterJob.createPrinterJob(curP);
PageLayout pp = curP.createPageLayout(Paper.LEGAL, PageOrientation.PORTRAIT, MarginType.DEFAULT);
PageLayout pl = curP.createPageLayout(Paper.LEGAL, PageOrientation.LANDSCAPE, MarginType.DEFAULT);
for(String p : pageList){
Printable pt = data.tables.get(p);
pt.scaleToFit();
if(pt.isLandscape()){
pj.printPage(pl,pt);
}
else{
pj.printPage(pp,pt);
}
}
pj.endJob();
// catch statements
}
However, whenever scaleToFit() is called for the first time (when ModPrintCycle is loaded), it tells me that the widths are 0, thus will not scale yet. The second time it is called (when I change between them for the first time), it's still 0. When it finally runs a 3rd time (when I look back at the Printable), it finally works and changes the widths as needed.
Since these Printables need to be printed, I cannot ensure that the forms are scaled until someone looks through all of them twice.
How do I force the forms to take their bounds before having to load them?

Since the code you posted is not fully executable (i.e. not MCVE or SSCCE), the problem cannot be reproduced. It is also difficult to guess the cause. But I see your purpose, so I suggest instead of scaling it manually, let the printable scale itself automatically through listener:
#Override
public void start( Stage stage )
{
ScrollPane scrollPane = new ScrollPane( new Printable( new Label( "looong loooong loooooong looooong loooong text" ) ) );
stage.setScene( new Scene( scrollPane ) );
stage.show();
}
class Printable extends VBox
{
public Printable( Node... children )
{
super( children );
Printable me = this;
this.widthProperty().addListener( new ChangeListener<Number>()
{
#Override
public void changed( ObservableValue<? extends Number> observable, Number oldValue, Number newValue )
{
double maxWidth = 100.0;
double width = newValue.doubleValue();
if ( width > maxWidth )
{
double widthFrac = maxWidth / width;
me.setScaleX( widthFrac );
}
}
} );
}
}

Why my GUI won't update even tho repaint() is being called?

I am having some difficulties using swing workers, timers, and I am actually a little confused.
As far as my understanding goes, I have to put on a timer to set-up recurring tasks that have to be called by the EDT.
I'm trying to make a program that shows graphically a sorting alghoritm (like this : https://www.youtube.com/watch?v=kPRA0W1kECg )
I just don't understand why the GUI won't refresh. I am quite sure the repaint method is being called since I put a sysout showing me the ordered values and it seems to work , but the GUI just... doesn't change.
Here's my code:
public class MainWindow {
private JFrame frame;
JPanel panel;
public final static int JFRAME_WIDTH = 800;
public final static int JFRAME_HEIGHT = 600;
public final static int NELEM = 40;
ArrayList<Double> numbers;
ArrayList<myRectangle> drawables = new ArrayList<myRectangle>();
Lock lock = new ReentrantLock();
Condition waitme = lock.newCondition();
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
MainWindow window = new MainWindow();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
public MainWindow() {
initialize();
}
private void initialize() {
frame = new JFrame();
frame.setBounds(100, 100, JFRAME_WIDTH + 20, JFRAME_HEIGHT + 40);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
panel = new myPanel();
frame.getContentPane().add(panel, BorderLayout.CENTER);
Timer timer = new Timer(500, new ActionListener() {
#Override
public void actionPerformed(ActionEvent arg0) {
lock.lock();
try{
//Updating the gui
panel.repaint();
panel.revalidate();
//Giving the OK to the sorting alghoritm to proceed.
waitme.signal();
}catch(Exception e){
e.printStackTrace();
}finally{
lock.unlock();
}
}
});
timer.start();
SwingWorker<Integer, String> sw = new SwingWorker<Integer, String>(){
#Override
protected Integer doInBackground() throws Exception {
mapAndCreate();
bubbleSort();
return null;
}
};
sw.execute();
}
private void bubbleSort() throws InterruptedException{
for(int i=0; i < NELEM; i++){
for(int j=1; j < (NELEM-i); j++){
if(drawables.get(j-1).wid > drawables.get(j).wid){
//swap the elements!
myRectangle temp = drawables.get(j-1);
drawables.set(j-1, drawables.get(j));
drawables.set(j, temp);
lock.lock();
try{
//Wait for the GUI to update.
waitme.await();
}catch(Exception e){
e.printStackTrace();
}finally{
lock.unlock();
}
}
}
}
}
/***
* Function that maps values from 0 to 1 into the rectangle width.
*/
private void mapAndCreate() {
double max = 0;
numbers = new ArrayList<Double>(NELEM);
//Finding maximum.
for(int i = 0; i < NELEM; i++){
Double currElem = Math.random();
if(currElem > max) max = currElem;
numbers.add(currElem);
}
//Mapping process
int offset = 0;
for(int j = 0; j < NELEM; j++){
Integer mapped = (int) (( JFRAME_WIDTH * numbers.get(j) ) / max);
myRectangle rect = new myRectangle(offset , mapped);
drawables.add(rect);
offset += JFRAME_HEIGHT / NELEM;
}
}
private class myRectangle{
int myy , wid , colorR,colorG,colorB;
public myRectangle(int y , int wid){
this.myy = y;
this.wid = wid;
Random r = new Random();
colorR = r.nextInt(255);
colorG = r.nextInt(255);
colorB = r.nextInt(255);
}
}
private class myPanel extends JPanel{
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
for(myRectangle rectan : drawables){
Graphics2D graphics2D = (Graphics2D)g;
System.out.println(rectan.wid);
Rectangle2D.Double rect = new Rectangle2D.Double(0,rectan.myy,rectan.wid,JFRAME_HEIGHT / NELEM);
graphics2D.setColor(new Color(rectan.colorR,rectan.colorG,rectan.colorB));
graphics2D.fill(rect);
}
System.out.println("====================================================================================================");
}
}
}

Most OSs (or rather the UI frameworks which they use) don't support concurrent access. Simply put, you can't render two strings of text at the same time.
That's why Swing runs all rendering operations in the UI thread. Calling rendering functions (like paint()) outside of the UI thread can cause all kinds of problems. So when you do it, Swing will just remember "I should repaint" and return (instead of doing any actual work). That way, Swing protects you but most people would prefer to get an error with a useful message.
A timer always also means that there is a thread somewhere which executes when the timer runs out. This is not the UI thread of Swing. So any paing operations there must be wrapped with EventQueue.invokeLater() or similar.
Another common bug is to hog the UI thread (so no rendering happens because you do complex calculations there). That's what the SwingWorker is for. Again, in most methods of the SwingWorker, calling methods which would render something is forbidden (-> use invokeLater()).
So my guess is that the UI thread waits for the lock and the lock simply isn't unlocked early or often enough. See this demo how to do a simple animation in Swing.
public class TimerBasedAnimation extends JPanel implements ActionListener {
public void paint(Graphics g) {
// setup
// do some first-run init stuff
// calculate the next frame
// render frame
}
public void actionPerformed(ActionEvent e) {
repaint();
}
public static void main(String[] args) {
JFrame frame = new JFrame("TimerBasedAnimation");
frame.add(new TimerBasedAnimation());
...
}
}
As you can see in the code doesn't lock. Instead, you just send "render now" events from actionPerformed to Swing. Some time later, Swing will call paint(). There is no telling (and no way to make sure or force Swing) when this will happen.
So good animation code will take the current time, calculate the animation state at that time and then render it. So it doesn't blindly step through N phases in M seconds. Instead, it adjusts for every frame to create the illusion that the animation is smooth when it really isn't.
Related:
Java: Safe Animations with Swing
How to Use Swing Timers

Problems repainting in a JPanel Runnable

I am writing a program that will play a song and have a JPanel displaying images during it. The song plays fine, the first image is drawn (I assume from the initial call to paintComponent) but somehow the repaint() doesn't seem to be getting called. I could really use an extra set of eyes. I have the code below for the JPanel class that will be displaying the images. Thanks so much!
class pictures extends JPanel implements Runnable {
private ImageIcon images[];
private Thread imagerunner;
private int currentImage;
pictures() {
super();
imagerunner = new Thread(this);
images = new ImageIcon[6];
imagerunner = new Thread(this);
images[0] = new ImageIcon("pic1.jpg");
images[1] = new ImageIcon("pic2.jpg");
images[2] = new ImageIcon("pic3.jpg");
images[3] = new ImageIcon("pic4.jpg");
images[4] = new ImageIcon("pic5.jpg");
images[5] = new ImageIcon("pic6.jpg");
currentImage = 0;
}
public void run() {
int i = 0;
System.out.println("starting pics");
while( i < 100 ) {
System.out.println("about to repaint()");
this.repaint();
System.out.println( "image: " + currentImage );
waiting( 2000 );
currentImage++;
}
System.out.println("done");
}
public void paintComponent( Graphics g ) {
super.paintComponent( g );
System.out.println("repainting");
images[ currentImage ].paintIcon(this,g,0,0);
}
public static void waiting (int n) {
long t0, t1;
t0 = System.currentTimeMillis();
do{
t1 = System.currentTimeMillis();
}
while (t1 - t0 < n);
}
}

You never start the thread imagerunner.
It is assigned twice (for no reason).
You can't modify GUI from another thread. Use Swing utilities for that.

The waiting() method seems to be blocking the EDT. It would be better to use a Swing Timer to schedule the updates.

You would need to do the following:
1) Actually create an instance to run.
2) You will need to invoke repaint() regularly in order to get your display to repaint.
Hope it helps. Cheers!

Make a main method wait on a smaller method (java)

i really need to find better ways to word my questions.
Basically I've created a program that takes information from a webpage and displays it nicely across the screen.
When the user closes the program, they actually hide it.
I also have another method which constantly loops checking for information to see if tis been updated.
unfortunately the problem im having is that it loops to fast, i only want it to check for information every 40 seconds or so.
What i tried was inserting a wait(1000,1000) in the method itself and in the main of the program. but both of these cause IllegalMonitorStateException.
Is this the correct way to make the thread wait properly? or is there a better way?
note: the only thread i have is the main.
MAIN
class Marquee
{
public static void main(String[] args) throws InterruptedException
{
MyFrame frame = new MyFrame();
frame.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
frame.setVisible(true);
frame.setAlwaysOnTop(true);
frame.setBackground(Color.BLACK);
frame.setResizable(true);
while(true)
{
// this doesnt work
frame.wait(1000,1000);
frame.notifyAll();
frame.checkForNewUpdate();
System.out.println(" ____________________________next line _______________________________");
}
}
}
CHECK FOR UPDATES
public String[] checkForNewUpdate()
{
//setVisible(true);
String tempUpdate = getEngineersUpdate();
if (latestUpdate[0] != tempUpdate)
{
// do nothign
setVisible(false);
}
else if(latestUpdate[0]==tempUpdate)
{
latestUpdate[0] = tempUpdate;
//show the page again
setVisible(true);
}
else if(latestUpdate[0]!= "NULL")
{
// do nothing
//latestUpdate[0] = tempUpdate;
}
else
{
latestUpdate[0] = tempUpdate;
}
return latestUpdate;
}
1: WHat am i doing wrong to get this exception
2: Is there any other way to make a gap of time in a method
3: Am i going to have to put all these methods into another thread? Please say no
// my constructor which I failed to mention has a timer in it. only i dont know hwo to use it
class MyFrame extends JFrame implements ActionListener
{
private ActionListener listener;
private Timer t1;
private String [] latestUpdate = new String[1];
public MyFrame()
{
Dimension d = Toolkit.getDefaultToolkit().getScreenSize();// gets the maximum size of the screen
setSize(d.width,(d.height/100)*10);//sets it to max. need to change this
// this shit find the max size of screen and puts it bottom left
GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
GraphicsDevice defaultScreen = ge.getDefaultScreenDevice();
Rectangle rect = defaultScreen.getDefaultConfiguration().getBounds();
int x = (int)rect.getMinX();
int y = (int)rect.getMaxY()-getHeight();
setLocation(x,y-30);
setTitle("ALERT::OUTAGE");
MyPanel panel = new MyPanel();
add(panel);
listener = this;
t1 = new Timer(50,listener);
t1.start();
}
by request, here is getEngineersUpdate()
public String getEngineersUpdate() //gets data from page and sets it to string.
{
String update = "blank";
final WebClient webClient = new WebClient();
webClient.setJavaScriptEnabled(false);// javascript causes some serious problems.
webClient.setCssEnabled(false);
String forChecking;
HtmlPage page;
try
{
URL outageURL = new URL("file:\\C:\\Users\\0vertone\\Desktop\\version control\\OUTAGE\\Outages.html"); //local drive at home
page = webClient.getPage(outageURL);
//All this crap can be gone if we just give the table an id
Object[] dates = page.getByXPath("//span[#id='date']/text()").toArray();
Object[] sites = page.getByXPath("//span[#id='site']/text()").toArray();
Object[] issues = page.getByXPath("//span[#id='issue']/text()").toArray();
System.out.println("" + dates[0].toString());
System.out.println("" + sites[0].toString());
System.out.println("" + issues[0].toString());
update = (dates[0].toString() + " " + sites[0].toString() + " " +issues[0].toString());
forChecking = dates[0].toString();
/**some examples of the getCellAt() method*/
//update = table.getCellAt(0,0).asText(); // This returns DATE/Time
//update = table.getCellAt(1,0).asText(); // This return the actual date
//update = table.getCellAt(0,1).asText(); // This returns, SITE/Sector
//update = table.getCellAt(1,1).asText(); // This returns the actual site issue
}
catch (FailingHttpStatusCodeException a)
{
System.out.println("Failing HTTP Status Execution");
a.printStackTrace();
}
catch (MalformedURLException b)
{
System.out.println("Malformed URL");
b.printStackTrace();
}
catch (IOException c)
{
System.out.println("IO PROBLEMS!");
c.printStackTrace();
}
webClient.closeAllWindows();
return update;
}

I've changed your code so it should work as you intended. I'm not clear on what getEngineersUpdate() does, so I can't say for sure if it will work, but I've given you a start. I've included 2 options for how to handle it, with explanation in the comments. You can see how to use a Timer properly in the constructor, also. Finally, I don't have your full code, so I had to rig something together to simulate it.
class Marquee {
public static void main(String[] args) throws InterruptedException {
MyFrame frame = new MyFrame();
frame.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
frame.setVisible(true);
frame.setAlwaysOnTop(true);
frame.setBackground(Color.BLACK);
frame.setResizable(true);
}
}
class MyFrame extends JFrame {
private String [] latestUpdate = new String[1];
private static final int DISPLAY_TIME = 3000;
private Timer displayTimer;
/*
* Option #1:
* Ideally, you'd have the thread that generates the "Engineers Update" messages call this
* method. If you can't make this event based, then you should use option #2
*/
public void newUpdate(String message) {
setVisible(true);
// change this to whatever you need to.
text.setText(message);
displayTimer.restart();
}
// I used this to test it
private JTextField text;
public MyFrame() {
// gets the maximum size of the screen
Dimension d = Toolkit.getDefaultToolkit().getScreenSize();
//sets it to max. need to change this
setSize(d.width, (d.height / 100) * 10);
// this shit find the max size of screen and puts it bottom left
GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
GraphicsDevice defaultScreen = ge.getDefaultScreenDevice();
Rectangle rect = defaultScreen.getDefaultConfiguration().getBounds();
int x = (int) rect.getMinX();
int y = (int) rect.getMaxY() - getHeight();
setLocation(x, y - 30);
setTitle("ALERT::OUTAGE");
//MyPanel panel = new MyPanel();
//add(panel);
text = new JTextField("Initial Text");
add(text);
// this creates a timer that when it goes off, will hide the frame
displayTimer = new Timer(DISPLAY_TIME, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
setVisible(false);
}
});
// sets the timer not to repeat
displayTimer.setRepeats(false);
//This code is for option #2:
updateTimer = new Timer(UPDATE_INTERVAL, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
checkForNewUpdate();
}
});
updateTimer.start();
}
// This is for option #2
private static final int UPDATE_INTERVAL = 1000;
private Timer updateTimer;
/*
* Option #2:
* Not ideal, but this should work.
*/
public String[] checkForNewUpdate() {
// I don't know how getEngineersUpdate() works
// which would have made it much easier to help you.
String tempUpdate = getEngineersUpdate();
// String comparison doesn't work like this in java.
// you also had a sleeping NullPointerException here
if (!tempUpdate.equals(latestUpdate[0])) {
// this is when you have a new update, correct?
newUpdate(tempUpdate);
latestUpdate[0] = tempUpdate;
} else if (tempUpdate.equals(latestUpdate[0])) {
// it's the same update as last time, so do nothing
} else if (tempUpdate.equals("NULL")) {
// You need to handle this according to what getEngineersUpdate() does
}
return latestUpdate;
}
// This code is rigged to show how it would work
private static int i = 0;
private String getEngineersUpdate() {
// 1 in 6 chance of returning "NULL"
if (Math.random() * 6 - 1 < 0)
return "NULL";
// probability of 1 in 4 of generating a new update
if(Math.random() * 4 - 1 < 0)
return "UPDATE #"+i++;
else
return "UPDATE #"+i;
}
}

I think you can't call wait() on an JFrame, but I am not sure.
You have to call wait() within a snychronized-block. (Example below)
Thread.sleep(1000l) can be used, if it runs in a Thread, but look for the class Timer
It would be much better design, if you create a thread, which checks for updates. You can notify the GUI (JFrame) with some kind of event-listener about the new date to display.
Take a look at the Timer and Callable.

You should create another thread, you should call checkforNewUpdate method from this thread. And also do not forget use SwingUtilities.invokeLater method to update your UI inside checkforNewUpdate method. here is the some part of the code;
public class Marque {
private JFrame frame;
class CheckForUpdate implements Runnable {
public void run() {
while(true) {
checkForNewUpdate();
try {
Thread.sleep(40000);
} catch (InterruptedException e1) {
e1.printStackTrace();
throw new RuntimeException(e1);
} }
}
public String[] checkForNewUpdate() {
//your code
// user interface interaction code
SwingUtilities.invokeLater(new Runnable() {
public void run() {
frame.setVisible(true);
}
});
}
}
public Marque() {
frame = new JFrame();
//....frame related code
new Thread(new CheckForUpdate()).start();
}
public static void main(String[] arg) {
Marque marque = new Marque();
}

How to create Show/Hide details button?

I am using Java Swing to create a JDialog, and i am trying to create a Show/Hide details button to show/hide a report at the bottom of this JDialog.
It works fine for me, but i want to do this with time, to add a small animation effect while showing/hiding the report, i have used TimerTask but it's just showing the report directly without any slow motion ... Here's my current code :
private void showHideDetailsButtonActionPerformed() {
final MyDialog myDialog = this;
int fullHeight = this.getHeight();
int smallHeight = this.getHeight()/2 - 4;
this.setSize( this.getWidth(), smallHeight ); // By default hide the report.
if( this.getHeight() == smallHeight ) { // Show details.
new Timer().schedule(
new java.util.TimerTask() {
#Override
public void run() {
while( myDialog.getHeight() < fullHeight ) {
myDialog.setSize( myDialog.getWidth(), myDialog.getHeight() + 1 );
System.out.println( myDialog.getHeight() );
}
}
},
800
);
}
}

Use javax.swing.Timer, not java.util.Timer... or use Trident.

Trying calling myDialog.repaint() after setting the size in the TimerTask's run() method.