What's the best way to 'link' JSliders to put a cap on the combined value?
Imagine a fighting game where the user can specify character traits like speed, agility, endurance and accuracy. The user is given 100 points to allocate however he chooses, but the total value of all the sliders must not exceed 100. That is, the sliders should not allow such increases.
If the user has allocated 30 points each to speed, agility and endurance, then the slider for accuracy should allow a maximum of 10 points (because 30 + 30 + 30 + 10 = 100). Notwithstanding, the range of the each slider should remain unchanged (in this case, 0 to 100).
I hope this makes sense. Thanks for the help.
"nichts einfacher als das" - dachte ... (insert name :-)
Basically, all such enhanced functionality must be implemented in the model: for JSlider, that's a BoundedRangeModel. Implement/extend and enforce its value to respect the "combined" max. Something like
public static class LimitedBoundedRangeModel extends DefaultBoundedRangeModel {
BoundedRangeModel limit;
public LimitedBoundedRangeModel(BoundedRangeModel limit) {
this.limit = limit;
}
/**
* #inherited <p>
*/
#Override
public void setRangeProperties(int newValue, int newExtent, int newMin,
int newMax, boolean adjusting) {
if (limit != null) {
int combined = newValue + limit.getValue();
if (combined > newMax) {
newValue = newMax - limit.getValue();
}
}
super.setRangeProperties(newValue, newExtent, newMin, newMax, adjusting);
}
}
// use
LimitedBoundedRangeModel firstModel = new LimitedBoundedRangeModel(null);
LimitedBoundedRangeModel secondModel = new LimitedBoundedRangeModel(firstModel);
firstModel.limit= secondModel;
JSlider first = new JSlider(firstModel);
JSlider second = new JSlider(secondModel);
While simple (two dependents only) and crude (direct bidirectional coupling) and as such not really usable out in the wild, it should at least work ... but doesn't - one of those surprises which hit me from time to time ;-) The visual problem is the thumb-position:
the combined max is respected when clicking to the right of the thumb: the thumb never moves over the threshhold
when dragging, the thumb can be moved everywhere which might be expected, as the ui isn't aware of the model tweak - it knows only the "local" max
on drag-end, the thumb remains at that invalid position.. which smells like a bug as now the thumb is out-off synch with the model
The reason for this misbehaviour is that the changeListener in Handler: it doesn't recalculate its thumb position when dragging (which is okay). The subtle bug is, that the internal dragging flag is only reset after the model's adjusting property is reset, so missing the very last notification about the final value ...
Hack around is to invoke the firing of an additional changeEvent, if the adjusting flag changes from true to false
boolean invoke =
(adjusting != getValueIsAdjusting()) && !adjusting;
super.setRangeProperties(newValue, newExtent, newMin, newMax, adjusting);
if (invoke) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
fireStateChanged();
}
});
}
Create 4 sliders and some variables: the maximum total value (say, 100) and the current total (0).
When the value of any of the sliders modifies, do:
// I hope my logic isn't failing me at this point
if (slider.getValue() > (maxTotal - currentTotal))
slider.setValue(maxTotal - currentTotal);
currentTotal = slider1.getValue() + slider2.getValue()
+ slider3.getValue() + slider4.getValue();
Related
I'd like to ask is it possible to stop knob moving further upon hit certain value in JScrollBar ?
For example, set the minimum and maximum value of a vertical scroll bar to 0 and 100. If the user scroll the knob till 60, he or she should not be able to move knob up further but able to move knob down.
Hence, I have simply wrote following adjust listener:
class MyAdjustmentListener2 implements AdjustmentListener
{
public void adjustmentValueChanged(AdjustmentEvent e)
{
label.setText("New Value is " + e.getValue() + " ");
if (e.getValue() < 60 )
{
vbar.setValue(60);
}
}
}
The label is a JLabel I used to monitor the adjusted value, the vbar is a vertical JScrollBar instance. Above code will force the knob jump back to value 60 if user try to move it above the value 60. This slightly different from what I want to achieve.
I have looked into the API of JScrollBar, I didn't found any straight method provided to use. Please share some hints to me here. Thank you for your time and suggestion.
Ok, i am creating a bukkit plugin which uses this event:
public void onCreatureSpawn(CreatureSpawnEvent e) {
// Do stuff
}
Inside of the event i need and if statement to fire every (x) amount of time the Creature event has been fired.
For instance if 10 creatures spawned, out of those 10, i would need the if statement to fire 2 times.
Out of the two creatures, 2 of them will get a special characteristic. My issue is, how can i make it so where this statement only fires (x) out of the many times it has been fired?
I have also tried something along the lines of the example below, but ran into some issues:
int outOf = Plugin.getConfig().getInt("armourSpawn");
int count = 1;
if(count%outOf==0) {
// This will fire (x) out of (x) times
}
count++;
Basically, the user will chose (x) out of 10 Monsters will have some certain characteristic in the config.
Out of ALL the creatures (that are monsters) that spawn i want a ration of (x) to 10 that have the characteristic.
To better illustrate the Random choice solution:
import java.util.Random;
Random rand = new Random();
int percentage = 25; //Set this to whatever percentage you want.
public void onCreatureSpawn(CreatureSpawnEvent e) {
//This will generate a number between 0 and 99 (inclusive)
int generatedNumber = rand.nextInt(100);
//If the generated number is smaller than the percentage you chose, you have "success".
if(generatedNumber < percentage){
addCharacteristic(creature, characteristic);
}else{
//Do whatever you need to normally.
}
}
I am programming a game, but I have ran into an error.
When the player collided with an object, player.hasCollided is set to true.
if(playerBounds.intersects(wolfBounds)){
player.hasCollided = true;
player.dead();
}
Now, when hasCollided is true, something from the LoseScreen class is printed out onto the screen:
if(player.hasCollided){
lose.start(g);
}
In player.dead(), the player's speed is set to 0.
public void dead(){
playerSpeed = 0;
coinBank += coinsCollected;
}
The problem is that in my InputHandler class I make it so that on the lose screen, when the choice is 1, and enter is pressed, restartGame() is called.
public void restartGame(){
obstacleWolf.getNewPosition();
obstacleHole.getNewPosition();
hasLost = false;
player.hasCollided = false;
player.playerSpeed = 5;
player.nextX = 1000;
player.coinsCollected = 0;
player.xElapsed = 0;
}
if(lose.choice == 1 && enter){
game.hasLost = false;
game.restartGame();
System.out.println(player.hasCollided + " " + player.playerSpeed);
}
Those variables ARE being set to what they are meant to be set to (for example playerSpeed becomes 5 from 0, and hasCollided is becoming false from true) but the effects are not taking place. So, like I showed before, lose.start(g); is only meant to be called when hasCollided is true, but even when it becomes false, it is still printed out on the screen.
Here is how the relevant variables/methods are being used:
public void move() {
x = x - player.playerSpeed;
}
(All moving objects share the same move method)
Parts of the game class:
public void tick(){
input.tick();
if(gameState){
player.tick();
player.move();
collision();
treeline.move();
obstacleHole.move();
obstacleWolf.move();
coin.move();
coin.tick();
}
I am not sure if I can make this question clearer. I can provide more code from different classes if needed.
The question can't be answered in its current form (see 2 comments above).
The reason for that is current code structure.
You need to refactor code, then you will find the problem.
Put all modification of player fields in methods of Player class.
Access fields only through methods. Making fields private is old good practice.
Then the only code you need to share would be this Player class.
In one thread environment, that's all.
I'm programming a simple game in java.
I've made a collision test with 30 FPS, where I had to get the size of the window.
Because I haven't had access to the GUI instance, I thought I'd make a shared instance, because this is pretty standard in Objective-C, where I come from.
class GUI extends JFrame {
private static GUI _sharedInstance;
public static GUI sharedInstance() {
if (_sharedInstance == null) {
_sharedInstance = new GUI();
}
return _sharedInstance;
}
}
But for some reason, it was really slow.
Then I replaced the shared instance with public static final instances for the size, and it works fast now, even with 60 FPS or higher.
Can anyone explain me why this happens?
EDIT
So instead of calling GUI.sharedInstance().getWidth(), I'm just calling GUI.windowSize.width.
I have used the public static final Dimension windowSize instead.
EDIT
Here's the collision detection.
So, instead of calling int width = GUI.kWindowWidth;,
I was calling int width = GUI.sharedInstance().getWidth(); before.
// Appears on other side
if (kAppearsOnOtherSide) {
int width = GUI.kWindowWidth;
int height = GUI.kWindowHeight;
// Slow
// int width = GUI.sharedInstance().getWidth();
// int width = GUI.sharedInstance().getHeight();
Point p = this.getSnakeHead().getLocation();
int headX = p.x;
int headY = p.y;
if (headX >= width) {
this.getSnakeHead().setLocation(new Point(headX - width, headY));
} else if (headX < 0) {
this.getSnakeHead().setLocation(new Point(headX + width, headY));
} else if (headY >= height) {
this.getSnakeHead().setLocation(new Point(headX, headY - height));
} else if (headY < 0) {
this.getSnakeHead().setLocation(new Point(headX, headY + height));
}
}
I know that this might not be the real answer to the question, but there could be a problem with a race condition.
I assume that you are trying to use the lazy/singleton pattern, because the construction of the GUI class is quite expensive and you need only one instance.
Now, what happens? If a thread runs into the if statement body, it creates a new GUI instance. Just before the next assignment, it gets paused by the scheduler.
Now another thread pops in, sees that _sharedInstance is still null and creates another GUI instance (and so on...).
Lets assume that there are only two threads.
The first thread runs to the end and the second one is continued, now you have two instances of the GUI class. Nobody says that the unassigned GUI instance gets destroyed or garbage collected.
That could explain tha 50 % performance loss compared to using finally and assigning the GUI instance directly to _sharedInstance.
See e.g. the Java examples at http://en.wikipedia.org/wiki/Singleton_pattern
Double checked locking, inner classes or an enum are the ways you can use.
Im creating an 'Avoid the Blocks' game, and for this i need to move a character around a grid (2D array) using the keys GHKJ. Every x amount of turns (decreasing as the level increases) a shadow must appear, then that shadow becomes a block and if the player moves into that bloack they lose a life.
Most of this is done for me other than the seemingly simple taski of getting the blocks to appear, here is my code so far for the falling blocks:
public void rocked(){
int rockInit = turn;
if(rockInit > 1){
int save = turn;
System.out.println(turn + " ");
B.board[ran.nextInt(12)][ran.nextInt(12)] = shadow;
if(save == turn - 3){
B.board[rockLocX][rockLocY] = rock;
}
}
}
The system.println is simply for debugging purposes, checking the values are being accesed. Turn is increased by 1 for every move the player makes, ran.nextInt(12) is a randomly generated number between 0 and 11, and B.board is the playing board.
It looks like you're never changing "save" after you initialize it to "turn". So then when you check if(save == turn-3), it will always be false, and so never move the block in. If you want to keep track of how many turns have passed, I would recommend a private instance variable "int turnsPassed" that you can increment each turn. Then for each level, you can check if (turnsPassed % x == 0), where x is as you've described it. Hope that helps!