Hey all, can anyone please explain how I can subclass UIButton and override some method so that when the user drags off a button it comes up right away? The problem is that when I drag out of the button frame it remains active and down. I want it to stop as soon as the finger leaves the button frame. Any ideas?
(Cocoa Touch)
If anyone ever has this problem, the following code allows for extremely accurate edge sensing while dragging. If you drag out of the button, it wont extend past the button's edge like normal.
(I subclassed UIButton and made the following:)
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
touchBlocker = TRUE;
self.highlighted = TRUE;
NSLog(#"Touch Began");
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [[event allTouches] anyObject];
CGPoint location = [touch locationInView:self];
if (touchBlocker) {
if (!CGRectContainsPoint([self bounds], location)) {
touchBlocker =FALSE;
self.highlighted = FALSE;
NSLog(#"Touch Exit");
}
} else if (CGRectContainsPoint([self bounds], location)) {
touchBlocker = TRUE;
self.highlighted = TRUE;
NSLog(#"Touch Enter");
}
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
touchBlocker = FALSE;
self.highlighted = FALSE;
NSLog(#"Touch Ended");
}
Related
I have a drawing simulation SKScene that works fine in iOS 7 that doesn't work in iOS 8. This is both for the simulator and the device.
The scene should show black lines where the finger touches the screen, and they should persist after you have finished "drawing" a line. Here's a screenshot of it in iOS 7:
Although there are no crashes, the lines don't render at all in iOS 8. I just get a blank canvas. NSLogging indicates that it does register the touchesBegan/Moved/Ended functions correctly.
I have produced the entire class in its entirety:
#implementation CSDraw
-(id)initWithSize:(CGSize)size type:(NSString *)CSType stresslevel:(NSInteger)stress_indicator { //designated initializer
if (self = [super initWithSize:size type: CSType stresslevel:stress_indicator]) {
NSLog(#"Creating new scene from CSDraw within the init");
}
return self;
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
self.swiped = NO;
UITouch *touch = [touches anyObject];
CGPoint positionInScene = [touch locationInNode:self];
self.pathToDraw = CGPathCreateMutable();
CGPathMoveToPoint(self.pathToDraw, NULL, positionInScene.x, positionInScene.y);
self.lineNode = [SKShapeNode node];
self.lineNode.path = self.pathToDraw;
self.lineNode.strokeColor = [SKColor blackColor];
self.lineNode.lineWidth = 10;
self.lineNode.zPosition = 50;
[self addChild:self.lineNode];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
self.swiped = YES;
UITouch* touch = [touches anyObject];
CGPoint positionInScene = [touch locationInNode:self];
CGPathAddLineToPoint(self.pathToDraw, NULL, positionInScene.x, positionInScene.y);
self.lineNode.path = self.pathToDraw;
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch* touch = [touches anyObject];
CGPoint positionInScene = [touch locationInNode:self];
if(!self.swiped) { //user just tapped once, draw a single point
SKSpriteNode *dot = [SKSpriteNode spriteNodeWithColor:[SKColor blackColor] size:CGSizeMake(10, 10)];
dot.position = positionInScene;
[self addChild: dot];
} else { //calls touchesMoved
}
//[self.lineNode removeFromParent]; //comment out this line if you want line to remain on screen
CGPathRelease(self.pathToDraw);
}
#end
This class was written from the code I found in this StackOverFlow answer.
I had a similar problem with a Sprite Kit iOS8 game and fixed it with something like this: Try adding a CGPathMoveToPoint call immediately before the CGPathAddLineToPoint call in your touchesMoved function.
According to the class reference for CGPathAddLineToPoint, calling CGPathAddLineToPoint automatically "updates the current point to the specified location (x,y) [the new endpoint]". However, my lines weren't getting rendered correctly in iOS8 until I did this manually by calling CGPathMoveToPoint before every CGPathAddLineToPoint call. Not sure why this is. Maybe a bug with Sprite Kit in iOS8.
Please find below the modified code, with changes marked with a /* new */ comment. The code assumes that you have a CGPoint property called lastPointTouched.
#implementation CSDraw
-(id)initWithSize:(CGSize)size type:(NSString *)CSType stresslevel:(NSInteger)stress_indicator { //designated initializer
if (self = [super initWithSize:size type: CSType stresslevel:stress_indicator]) {
NSLog(#"Creating new scene from CSDraw within the init");
}
return self;
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
self.swiped = NO;
UITouch *touch = [touches anyObject];
CGPoint positionInScene = [touch locationInNode:self];
self.pathToDraw = CGPathCreateMutable();
CGPathMoveToPoint(self.pathToDraw, NULL, positionInScene.x, positionInScene.y);
/* new */ self.lastPointTouched = positionInScene;
self.lineNode = [SKShapeNode node];
self.lineNode.path = self.pathToDraw;
self.lineNode.strokeColor = [SKColor blackColor];
self.lineNode.lineWidth = 10;
self.lineNode.zPosition = 50;
[self addChild:self.lineNode];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
self.swiped = YES;
UITouch* touch = [touches anyObject];
CGPoint positionInScene = [touch locationInNode:self];
/* new */ CGPathMoveToPoint(self.pathToDraw, NULL, self.lastPointTouched.x, self.lastPointTouched.y);
CGPathAddLineToPoint(self.pathToDraw, NULL, positionInScene.x, positionInScene.y);
/* new */ self.lastPointTouched = positionInScene;
self.lineNode.path = self.pathToDraw;
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch* touch = [touches anyObject];
CGPoint positionInScene = [touch locationInNode:self];
if(!self.swiped) { //user just tapped once, draw a single point
SKSpriteNode *dot = [SKSpriteNode spriteNodeWithColor:[SKColor blackColor] size:CGSizeMake(10, 10)];
dot.position = positionInScene;
[self addChild: dot];
} else { //calls touchesMoved
}
//[self.lineNode removeFromParent]; //comment out this line if you want line to remain on screen
CGPathRelease(self.pathToDraw);
}
#end
I have a Menu ("myMenu") containing CCMenuItemImages. I would like this menu to detect finger swipes and slide accordingly.
My problem is that the CCMenuItemImages seem to absorb the touch event. The swipe works fine when the user touches the menu outside of the CCMenuItemImages, but not when the touch happens on these.
I have tried to put my menu items in a layer to detect touches (refering to answer Scrollable menu using MenuItem's), but this doesn't seem to work either. Any idea why ?
+(id) scene
{
CCScene *scene = [CCScene node];
ModeMenuScene *layer = [ModeMenuScene node];
[scene addChild: layer];
return scene;
}
-(id) init
{
if( (self=[super init] )) {
CGSize winSize = [[CCDirector sharedDirector] winSize];
CCSprite *background = [CCSprite spriteWithFile:#"bg.png"];
background.position=ccp(winSize.width/2,winSize.height/2);
[self addChild:background];
mode1 = [CCMenuItemImage itemFromNormalImage:#"Mode1.png" selectedImage: #"Mode1.png" target:self selector:#selector(goToMode1:)];
mode1label = [CCLabelTTF labelWithString:[NSString stringWithFormat:#"Level 1 %d", n] dimensions:CGSizeMake(220,53) alignment:UITextAlignmentCenter fontName:#"Arial" fontSize:20.0];
mode1label.color = ccc3(167,0,0);
mode1label.position=ccp(55,-30);
[mode1 addChild:mode1label];
// here same kind of code to define mode2,mode3,mode4 (taken out to reduce size of code)
myMenu=[CCMenu menuWithItems:mode1,mode2,mode3,mode4,nil];
[myMenu alignItemsHorizontallyWithPadding:25];
myMenu.position=ccp(winSize.width/2+40,180);
menuLayer = [CCLayer node];
[menuLayer addChild:myMenu];
[self addChild:menuLayer];
[self enableTouch];
}
return self;
}
-(void) disableTouch{
self.isTouchEnabled=NO;
menuLayer.isTouchEnabled=NO;
}
-(void) enableTouch{
self.isTouchEnabled=YES;
menuLayer.isTouchEnabled=YES;
}
-(void) ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [touches anyObject];
CGPoint location = [touch locationInView:[touch view]];
if(location.y>100 && location.y<260) {
draggingMenu=1;
x_initial = location.x;
}
else draggingMenu=0;
}
-(void) ccTouchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [touches anyObject];
CGPoint location = [touch locationInView:[touch view]];
if(draggingMenu==1) {
CGSize winSize = [[CCDirector sharedDirector] winSize];
int x = myMenu.position.x+location.x-x_initial;
x = MAX(0,x);
x = MIN(x,winSize.width/2+40);
myMenu.position=ccp(x,180);
x_initial=location.x;
}
}
- (void) ccTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
draggingMenu=0;
}
- (void)dealloc {
[super dealloc];
}
#end
Solved it by adding :
-(void) registerWithTouchDispatcher
{
[[CCTouchDispatcher sharedDispatcher] addTargetedDelegate:self priority:INT_MIN+1 swallowsTouches:NO];
}
the problem was that CCMenuItemImage swallows the touches and has a high priority set at -128. Thus the need to set priority at INT_MIN+1
I am trying to implement an undo/redo method using NSUndoManager. I have asked other questions on this, but am still stuck.
Where I am at the moment is as follows:
.h
NSUndoManager *undoManager;
#property(nonatomic,retain) NSUndoManager *undoManager;
.m
#synthesize undoManager;
[undoManager setLevelsOfUndo:99];
viewdidload:
NSNotificationCenter *dnc = [NSNotificationCenter defaultCenter];
[dnc addObserver:self selector:#selector(undoButtonTapped) name:#"undo" object:nil];
[dnc addObserver:self selector:#selector(redoButtonTapped) name:#"redo" object:nil];
- (void)resetTheImage:(UIImage*)image
{
NSLog(#"%s", __FUNCTION__);
// image = savedImage.image;
if (image != drawImage.image)
{
[[undoManager prepareWithInvocationTarget:self] resetTheImage];
image = drawImage.image ;
} else {
NSLog(#"That didn't work");
}
}
- (void)undoButtonTapped {
NSLog(#"%s", __FUNCTION__);
[undoManager undo];
}
I get "That didn't work"...
I would appreciate help. I will post the answer to my original question when I figure out what I'm doing wrong.
---EDIT---
I have changed resetTheImage as follows:
- (void)resetTheImage:(UIImage*)image
{
NSLog(#"%s", __FUNCTION__);
image = savedImage.image;
if (image != drawImage.image)
{
drawImage.image = image;
savedImage.image = image;
NSLog(#"undo image");
[[self.undoManager prepareWithInvocationTarget:drawImage.image] image];
} else {
NSLog(#"same image");
savedImage.image = image;
}
}
However, confusion rains - it may help if someone (Brad?, Justin?) can provide a bullet point list of the steps I need to take to get this working. For example:
. Add notifications in ...
. Trigger notifications....
. Have undo /redo buttons point to...
. What methods/functions I really need to build..
....
I wish SO would allow me to give you more points than 1..
(It doesn't help that my "o" key is getting wonky)
It does help that I had a baby granddaughter yesterday :))))
First, I want to thank everyone for any/all assistance. I solved this finally although I'm not sure if it's the best solution.
I made a UIView called from the UIViewController. The controls (colors and brushes) remain in the VC. The drawing methods move to the View Method.
The View Method calls a Drawing method to actually perform the draw, and the View method controls the undo/redo.
Here are some code snippets:
-(void)undoButtonClicked
{
//NSLog(#"%s", __FUNCTION__);
if ([self.currentArray count] == 0) {
//nothing to undo
return;
}
DrawingPath *undonePath = [self.currentArray lastObject];
[self.currentArray removeLastObject];
[self.redoStack addObject:undonePath];
[self setNeedsDisplay];
}
-(void)redoButtonClicked
{
//NSLog(#"%s", __FUNCTION__);
if ([self.redoStack count] == 0) {
// nothing to redo
return;
}
DrawingPath *redonePath = [self.redoStack lastObject];
[self.redoStack removeLastObject];
[self.currentArray addObject:redonePath];
[self setNeedsDisplay];
}
Let me know if anyone wants clarification. Thanks all again..
UPDATE as requested:
These are some headers:
DrawingViewController *mvc;
NSMutableArray *pathArray;
NSMutableArray *colorArray;
NSMutableArray *bufferArray;
NSMutableArray *currentArray;
UIBezierPath *myPath;
NSString *brushSize;
CGPoint lastPoint;
int colorIndex;
NSString *colorKey;
SoundEffect *erasingSound;
SoundEffect *selectSound;
BOOL swiped;
int moved;
UIColor *currentColor;
NSString *result;
}
#property(nonatomic,assign) NSInteger undoSteps;
#property (strong, nonatomic) NSString *result;
#property (strong,nonatomic) UIColor *currentColor;
#property (strong,nonatomic) NSMutableArray *currentArray;
#property (strong,nonatomic) NSMutableArray *bufferArray;
#property (strong,nonatomic) DrawingPath *currentColoredPath;
#property (strong,nonatomic) NSMutableArray *redoStack;
#property (strong, nonatomic) NSString *colorKey;
and here are some more of the methods.. The currentArray then keeps track of points, brush and color in a sort of stack. Undo removes from the stack, and adds into a temp stack that can be used to Redo.
-(void)undoButtonClicked
{
//NSLog(#"%s", __FUNCTION__);
if ([self.currentArray count] == 0) {
//nothing to undo
return;
}
DrawingPath *undonePath = [self.currentArray lastObject];
[self.currentArray removeLastObject];
[self.redoStack addObject:undonePath];
[self setNeedsDisplay];
}
-(void)redoButtonClicked
{
//NSLog(#"%s", __FUNCTION__);
if ([self.redoStack count] == 0) {
// nothing to redo
return;
}
DrawingPath *redonePath = [self.redoStack lastObject];
[self.redoStack removeLastObject];
[self.currentArray addObject:redonePath];
[self setNeedsDisplay];
}
#pragma mark - Touch Methods
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
//NSLog(#"%s", __FUNCTION__);
self.currentColoredPath = [[DrawingPath alloc] init];
[self.currentColoredPath setColor:self.currentColor];
UITouch *touch= [touches anyObject];
[self.currentColoredPath.path moveToPoint:[touch locationInView:self]];
[self.currentArray addObject:self.currentColoredPath];
// Remove all paths from redo stack
[self.redoStack removeAllObjects];
lastPoint = [touch locationInView:self];
lastPoint.y -= 20;
if ([touch tapCount] == 2) {
[self alertOKCancelAction];
return;
}
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
//NSLog(#"%s", __FUNCTION__);
UITouch *touch = [touches anyObject];
[self.currentColoredPath.path addLineToPoint:[touch locationInView:self]];
[self setNeedsDisplay];
CGPoint currentPoint = [touch locationInView:self];
currentPoint.y -= 20;
lastPoint = currentPoint;
}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
//NSLog(#"%s", __FUNCTION__);
self.currentColoredPath = nil;
}
I have a simple drawing class. There is a view controller that includes a color selection bar. Then a UIView that has the CGRect draw functions.
I can draw ok, but when I change the color, all existing strokes are changed. What have I messed up? I want to only change colors for new strokes.
Any help would be welcome. Here are some relevant code snippets:
- (void)drawRect:(CGRect)rect
{
[currentColor setStroke];
for (UIBezierPath *_path in pathArray)
[_path strokeWithBlendMode:kCGBlendModeNormal alpha:1.0];
}
#pragma mark - Touch Methods
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
swiped = NO;
myPath=[[UIBezierPath alloc]init];
myPath.lineWidth=10;
UITouch *touch= [touches anyObject];
[myPath moveToPoint:[touch locationInView:self]];
[pathArray addObject:myPath];
if ([touch tapCount] == 2) {
[self eraseButtonClicked];
return;
}
lastPoint = [touch locationInView:self];
lastPoint.y -= 20;
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
swiped = YES;
UITouch *touch = [touches anyObject];
CGPoint currentPoint = [touch locationInView:self];
currentPoint.y -= 20;
[myPath addLineToPoint:[touch locationInView:self]];
[self setNeedsDisplay];
UIGraphicsBeginImageContext(self.frame.size);
CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 15.0);
CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), red, green, blue, 1.0);
CGContextBeginPath(UIGraphicsGetCurrentContext());
CGContextMoveToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), currentPoint.x, currentPoint.y);
CGContextStrokePath(UIGraphicsGetCurrentContext());
UIGraphicsEndImageContext();
lastPoint = currentPoint;
moved++;
if (moved == 10) {
moved = 0;
}
}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
if ([touch tapCount] == 2) {
[self eraseButtonClicked];
return;
}
}
Your drawRect: is drawing all the paths in the same colour. When you call [currentColor setStroke], you are setting the colour for all the strokes you draw. You'll need to maintain the colours for the strokes as well, and reset the colour before each call to strokeWithBlendMode.
Something like:
- (void)drawRect:(CGRect)rect
{
for( int i=0; i<[pathArray count]; i++) {
[[colorArray objectAtIndex:i] setStroke];
[[pathArray objectAtIndex:i] strokeWithBlendMode:kCGBlendModeNormal alpha:1.0];
}
}
You'll have to make sure you add a UIColor object to the colorArray every time you add a path to pathArray.
You could add [colorArray addObject:currentColor]; after the line [pathArray addObject:myPath];
Imagine that i drag an ImageView in TouchesMoved,how can i recognize that in which direction i dragged it from code ?
You can store a temporary Point from touchesBegan. Add a iVar in "YourImageView" interface.
#interface YourImageView : UIImageView
{
CGPoint previousPt;
//Other iVars.
}
#end
#implementation YourImageView
- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
previousPt = [[touches anyObject] locationInView:self.view];
}
- (void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
const CGPoint p = [[touches anyObject] locationInView:self.view];
if (previousPt.x > p.x)
{
//Dragged right to left
}
else if (previousPt.x < p.x)
{
//Dragged left to right
}
else
{
//no move
}
//Do the same thing for y-direction
}
I would extract a method out of it. But I hope you got the idea.
If you subtract the old position from the new position of the ImageView, then you will get a direction vector. If you want a unit vector, just normalize it.