Animating the NSLevelIndicator when the values change - objective-c

Currently I have the following code to update the NSLevelindicator:
[self.headerIndicator selfFloatValue:heightValue]
Is there any way to animate the the level indicator between values when they update?

read this answer to animating sliders. i haven't tried it with level indicators but from the API docs it seems a viable option. the source code there can easily be adapt: NSSlider animation

I have tried this code and it works fine:
Swift:
self.CpuLevel.maxValue = Double(value)

If [[[self.headerIndicator] animator] setFloatValue:heightValue]; doesn't work, you must add the capability yourself. See NSAnimatablePropertyContainer.

You could write your own method, something like this to change the level. The math in there tries to keep the total "animation" time equal regardless of how big the transition is from the old value to the new (around 1 second with these values).
-(void)updateLevel:(NSNumber *) newLevelNum {
float currentLevel = self.level.floatValue;
float newLevel = newLevelNum.floatValue;
if (self.delay == 0.0) // self.delay is a float property set to 0.0 elsewhere
self.delay = .2 /(newLevel - currentLevel);
[self.level setFloatValue:currentLevel + .2];
if (self.level.floatValue - newLevel < .01){
[self performSelector:#selector(updateLevel:) withObject:newLevelNum afterDelay:self.delay];
}
}

Related

SpriteKit displaying variable number

What is the best way to display some value (that changes as the game runs) on the screen in iPhone SpriteKit? The only way I can think of is SKLabelNode, but it's probably not meant to be used like this and also I can't find any way to measure its width, which makes me unable to position it correctly (I want it to be in the bottom right corner). Thanks in advance :).
#Edit
My attempt at doing this:
SKLabelNode *someLabel = [SKLabelNode labelNodeWithFontNamed:#"Chalkduster"];
someLabel.text = some_string;
someLabel.fontSize = 30;
someLabel.fontColor = [SKColor blackColor];
someLabel.position = CGPointMake(some_int, 15);
[self addChild:someLabel];
The values of some_string and some_int change as the game runs, so someLabel is removed, someLabel.text and someLabel.position are re-assigned, and the label is added again. Yes, I am aware that this is a bad way to do this...
Unfortunately, SKLabelNode is your simplest bet, it's just not the most robust tool.
You just want to update its text and its position when you need to. Your code is correct, and if you want to get its actual size, then you would get the width of its frame.
update text:
someLabel.text = theNewText;
update position:
someLabel.position = theNewPosition;
get relative width
float widthOfLabelFrame = someLabel.frame.size.width;
additional alignment settings that might help (vertical baseline is the default):
someLabel.horizontalAlignmentMode = SKLabelHorizontalAlignmentModeRight;
someLabel.verticalAlignmentMode = SKLabelVerticalAlignmentModeBaseline;

Add boundaries to an SKScene

I'm trying to write a basic game using Apple's Sprite Kit framework. So far, I have a ship flying around the screen, using SKPhysicsBody. I want to keep the ship from flying off the screen, so I edited my update method to make the ship's velocity zero. This works most of the time, but every now and then, the ship will fly off the screen.
Here's my update method.
// const int X_MIN = 60;
// const int X_MAX = 853;
// const int Y_MAX = 660;
// const int Y_MIN = 60;
// const float SHIP_SPEED = 50.0;
- (void)update:(CFTimeInterval)currentTime {
if (self.keysPressed & DOWN_ARROW_PRESSED) {
if (self.ship.position.y > Y_MIN) {
[self.ship.physicsBody applyForce:CGVectorMake(0, -SHIP_SPEED)];
} else {
self.ship.physicsBody.velocity = CGVectorMake(self.ship.physicsBody.velocity.dx, 0);
}
}
if (self.keysPressed & UP_ARROW_PRESSED) {
if (self.ship.position.y < Y_MAX) {
[self.ship.physicsBody applyForce:CGVectorMake(0, SHIP_SPEED)];
} else {
self.ship.physicsBody.velocity = CGVectorMake(self.ship.physicsBody.velocity.dx, 0);
}
}
if (self.keysPressed & RIGHT_ARROW_PRESSED) {
if (self.ship.position.x < X_MAX) {
[self.ship.physicsBody applyForce:CGVectorMake(SHIP_SPEED, 0)];
} else {
self.ship.physicsBody.velocity = CGVectorMake(0, self.ship.physicsBody.velocity.dy);
}
}
if (self.keysPressed & LEFT_ARROW_PRESSED) {
if (self.ship.position.x > X_MIN) {
[self.ship.physicsBody applyForce:CGVectorMake(-SHIP_SPEED, 0)];
} else {
self.ship.physicsBody.velocity = CGVectorMake(0, self.ship.physicsBody.velocity.dy);
}
}
}
At first, I used applyImpulse in didBeginContact to push the ship back. This made the ship bounce, but I don't want the ship to bounce. I just want it to stop at the edge.
What is the right way to make the ship stop once it reaches the edge? The code above works most of the time, but every now and then the ship shoots off screen. This is for OS X—not iOS—in case that matters.
Check out this link...
iOS7 SKScene how to make a sprite bounce off the edge of the screen?
[self setPhysicsBody:[SKPhysicsBody bodyWithEdgeLoopFromRect:self.frame]]; //Physics body of Scene
This should set up a barrier around the edge of your scene.
EDIT:
This example project from Apple might also be useful
https://developer.apple.com/library/mac/samplecode/SpriteKit_Physics_Collisions/Introduction/Intro.html
Your code is not clear in what the velocity variables represent. Keep in mind that if the velocity is too high your ship will have travelled multiple points between updates. For example, your ship's X/Y is at (500,500) at the current update. Given a high enough velocity, your ship could be at (500,700) at the very next update. If you had your boundary set at (500,650) your ship would already be past it.
I suggest you do a max check on velocity BEFORE applying it to your ship. This should avoid the problem I outlined above.
As for bouncy, bouncy... did you try setting your ship's self.physicsBody.restitution = 0; ? The restitution is the bounciness of the physics body. If you use your own screen boundaries, then I would recommend setting those to restitution = 0 as well.
Your best bet would be to add a rectangle physics body around the screen (boundary). Set the collision and contact categories of the boundary and player to interact with each other. In the didBeginContact method you can check if the bodies have touched and, if they have, you can call a method to redirect the ship.
Your problem is that your update method may not be checking the location frequently enough before the ship gets off screen.
This will help you to define you screen edges in Swift.
self.physicsBody = SKPhysicsBody ( edgeLoopFromRect: self.frame )

UICollectionView with preview and paging enabled

I am trying to imitate what Apple has when showing the search result in the App Store. (reference: http://searchengineland.com/apple-app-search-shows-only-one-result-at-a-time-133818)
It shows like the detailed-application-info in a cards and it is paged. I am stuck at how to make the previous-and-next card shows when one active card in the middle and the scroll view's paging behaviour is still intact.
I have tried using the UICollectionView and set the clipSubviews to NO, hoping that it will show the previous page and the next page, but as soon as the cell goes off-screen, the cell gets hidden (removed from the view hierarchy) and not displayed. I think thats the flyweight pattern of the UICollectionView (the behavior of UICollectionView). Any ideas of what would be possible?
Cheers,
Rendy Pranata
The problem: UICollectionView as a subclass of UIScrollView essentially animates its bounds by a stride of bounds.size. Although this could mean that all you had to do is decrease the bounds while keeping the frame bigger, unfortunately UICollectionView will not render any cells outside its current bounds... destroying your preview effect.
The Solution:
Create a UICollectionView with paging set to NO and with the desired frame.
Create UICollectionViewCells that are smaller than the UICollectionView's frame/bounds. At this stage, a part of the next cell should show in the frame. This should be visible before implementing the other steps below.
Add a collectionView.contentInset.left and right (I assume your layout is horizontal) equal to the contentOffsetValue method (as shown below for simplicity) so as to align the first and last cells to the middle.
Create a UICollectionViewFlowLayout which overrides the method that gives the stopping point like so:
Like so:
-(CGFloat)contentOffsetValue
{
return self.collectionView.bounds.size.width * 0.5f - self.itemSize.width * 0.5f;
}
- (CGPoint)targetContentOffsetForProposedContentOffset:(CGPoint)proposedContentOffset withScrollingVelocity:(CGPoint)velocity
{
static float EscapeVelocity = 0.5f; // otherwise snap back to the middle
NSArray* layoutAttributesArray = [self layoutAttributesForElementsInRect:self.collectionView.bounds];
if(layoutAttributesArray.count == 0)
return proposedContentOffset;
CGFloat currentBoundsCenterX = self.collectionView.contentOffset.x + self.collectionView.bounds.size.width * 0.5f;
UICollectionViewLayoutAttributes* candidateNextLayoutAttributes = layoutAttributesArray.firstObject;
for (UICollectionViewLayoutAttributes* layoutAttributes in layoutAttributesArray)
{
if ((layoutAttributes.representedElementCategory != UICollectionElementCategoryCell) ||
(layoutAttributes == candidateNextLayoutAttributes)) // skip the first comparison
continue;
if(velocity.x > EscapeVelocity || velocity.x < -(EscapeVelocity))
{
if(velocity.x > EscapeVelocity && layoutAttributes.center.x > candidateNextLayoutAttributes.center.x)
{
candidateNextLayoutAttributes = layoutAttributes;
}
else if (velocity.x < -(EscapeVelocity) && layoutAttributes.center.x < candidateNextLayoutAttributes.center.x)
{
candidateNextLayoutAttributes = layoutAttributes;
}
}
else
{
if(fabsf(currentBoundsCenterX - layoutAttributes.center.x) < fabsf(currentBoundsCenterX - candidateNextLayoutAttributes.center.x))
{
candidateNextLayoutAttributes = layoutAttributes;
}
}
}
return CGPointMake(candidateNextLayoutAttributes.center.x - self.collectionView.bounds.size.width * 0.5f, proposedContentOffset.y);
}
I just put together a sample project which shows how you could do this. I created a container view which is 100 points wider than the 320 points for the screen. Then I put a UICollectionView into that container. This offsets everything by 50 points on both sides of the screen.
Then there is a content cell which simply has a background and a label so you can visually identify what is happening. On the left and right there are empty cells. In the viewDidLoad method the content inset is set to negative values on the left and right to make the empty cells now scroll into view. You can adjust the inset to your preference.
This mimics the behavior fairly closely. To get the label below, like in the example you can simply check the contentOffset value to determine which cell is in focus. To do that you'd use the UIScrollViewDelegate which is a part of UICollectionView.
https://github.com/brennanMKE/Interfaces/tree/master/ListView
You'll notice this sample project has 2 collection views. One is a normal horizontal flow layout while the other one which has larger cells is the one which mimics the example you mentioned.

MKOverlayPathView Trouble enabling user to define pathWidth

Ok so I'm using Apples IOS Breadcrumb [Sample Code][1] .
I've a slider to the BreadcrumbViewController.xib called "lineWidth" and have a UIlabel which shows the value of the slider being changed called "sliderLabel". This I can do with relative ease.
Although now I want whatever number is in the sliderLabel to affect the CrumbPath lineWidth which at the moment is in CrumbPathView.m
{
CrumbPath *crumbs = (CrumbPath *)(self.overlay);
CGFloat lineWidth = MKRoadWidthAtZoomScale(zoomScale);
Now this can be changed to
CGFloat lineWidth = 200;
Or whatever.
so my question is how do I store the value of the sliderLabel located in the BreadcrumbViewController.xib (which is linked to the BreadcrumbViewController.h &.m) and retrieve the stored value (INT) in the CrumbPathView.m?
Im still learning so be nice.
Thank you in advance.

cocos2d progress bar

HI all,
i am developing a puzzle game in iPhone using cocos2d.I need a progress bar (like uiprogress bar) to show the game progress time.But i can't find any good example...
can anyone tell me the way???
well....i get a better solution...here is my code
CCProgressFromTo *to1 = [CCProgressFromTo actionWithDuration:levelTimeLimit from:100 to:0];
timeBar = [CCProgressTimer progressWithFile:#"Bar.png"];
timeBar.type = kCCProgressTimerTypeHorizontalBarLR;
[timeBar setPosition:ccp(384,84)];
[self addChild:timeBar];
[timeBar runAction:to1];
there is a class called CCProgressTimer in latest version of cocos2d..
thanks
You can use a CCSprite that you set the width of using
yourSprite.scaleX = 0.5 //This goes between 0.0 and 1.0.
You will have to calculate the required width, percentage and scaleX-factor manually but its pretty simple. I did my fiend hp bar implementation like this:
-(void)decreaseHp:(float)hpIn {
self.hp = self.hp-hpIn; //Decrease HP by specified amount.
float p = (self.hp*100)/self.maxHp; //Calculate new hp percentage.
self.hpBar.scaleX = p/100; //Convert percentage to a factor between 0 and 1.
}
self is the Fiend object and hpBar is a simple CCSprite with anchor ccp(0,0).
You you don't want you progress bar to stretch, but move instead, you will have to mask it with something and update its position instead of scaleX.