How to get the object that called the method in iOS? - ios

I have a button that calls a method. I need to access that button inside the method. I don't know how you can access the caller of a method.

-(void)myButtonAction: (id)sender
{
if ([sender isKindOfClass: [UIButton class]])
{
UIButton* btn = sender;
// do something! :)
}
}

if you're using IBAction for handling button event, the sender passed to you will be your button:
- (void) onButtonAction: (id) sender
{
NSLog(#"sender object description %#", sender);
}

Related

How to use sender attributes in Objective-C

I'm using two buttons to do the same action. How can I identify which button was pressed using the "sender" from my IBAction function? (each button has a different Tag)
Here is what I want to do:
- (IBAction)addItemInParent:(id)sender {
NSInteger choice = sender.tag;
}
I hope this question makes sense!
- (IBAction)addItemInParent:(id)sender
{
UIButton *buttonPressed = (UIButton *)sender;
if (buttonPressed.tag == 123)
{
//button with tag 123 was pressed
}else if (buttonPressed.tag == 124
{
//button with tag 124 was pressed
}
}
Just replace my 123 and 124 with what the button tags actually are.
If you are confident that this method is only invoked by a button press, then you can rewrite your method to this one:
- (IBAction)addItemInParent:(UIButton *)sender {
NSInteger choice = sender.tag;
}
If not, check for the class of the sender:
- (IBAction)addItemInParent:(id)sender {
if ([sender isKindOfClass:[UIButton class]]) {
UIButton *button = (UIButton *)sender;
NSInteger choice = button.tag;
}
else {
// handle other cases
}
}
Change id to UIButton like so:
- (IBAction)addItemInParent:(UIButton *)sender {
NSInteger choice = sender.tag;
}
After casting sender to UIButton, did you try:
if (choice == 101)
{
// button whatever was pressed
}
else
{
// the other button was pressed
}
Obviously you should use the tags you assigned to the buttons.
You need to
1) check if the id object is a actually UIView class or subclass
2) typecast the id object to UIView
3) check the tag
4) decide what next based on the tag
if ([sender isKindOfClass:([UIView class])])
{
NSInteger tag = ((UIView *)sender).tag;
if (tag == <tag of button 1>)
{
//do something
}
else if (tag == <tag of button 2>)
{
//do something else
}
}
You need to typecast because id can be any type of object and you must make sure that it is actually an instance of UIView class or subclass to be able to access the tag, as only UIView classes and subclasses have a tag property.

How to implement two IBActions in UIButton without overlap?

I drag 2 IBActions from a UIButton, one with touchDown event and second with drag Inside.
- (IBAction)clickButton:(UIButton *)sender {
NSLog(#"Click Button");
}
- (IBAction)dragInsideButton:(UIButton *)sender {
NSLog(#"Drag Button");
}
But when I drag inside, the touchDown action also gets fired.
How to disable touchDown event when dragInside.
Thanks!
i have solved a problem like this with using drag Events
add events to your button in .xib file or programatically.
programmatically is:
[mybut addTarget:self action:#selector(dragBegan:withEvent: )
forControlEvents: UIControlEventTouchDown];
[mybut addTarget:self action:#selector(dragMoving:withEvent: )
forControlEvents: UIControlEventTouchDragInside];
[mybut addTarget:self action:#selector(dragEnded:withEvent: )
forControlEvents: UIControlEventTouchUpInside |
UIControlEventTouchUpOutside];
then defininitons of events are:
- (void) dragBegan: (UIButton *) c withEvent:ev
{
NSLog(#"dragBegan......");
count=NO;//bool Value to decide the Down Event
c.tag=0;
[self performSelector:#selector(DownSelected:) withObject:mybut afterDelay:0.1];
//user must begin dragging in 0.1 second else touchDownEvent happens
}
- (void) dragMoving: (UIButton *) c withEvent:ev
{
NSLog(#"dragMoving..............");
c.tag++;
}
- (void) dragEnded: (UIButton *) c withEvent:ev
{
NSLog(#"dragEnded..............");
if (c.tag>0 && !count)
{
NSLog(#"make drag events");
}
}
-(void)DownSelected:(UIButton *)c
{
if (c.tag==0) {
NSLog(#"DownEvent");
count=YES;//count made Yes To interrupt drag event
}
}
This method is tested, and should do what I think you're trying to do. You can change the delay in the timer to get the effect you want. I had to connect 3 actions to the button to make this work -- the third action is a touchUp that resets the system to the starting condition.
#interface LastViewController ()
#property (nonatomic) BOOL touchedDown;
#property (strong,nonatomic) NSTimer *downTimer;
#end
#implementation LastViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.touchedDown = NO;
}
-(IBAction)clickDown:(id)sender {
self.downTimer = [NSTimer scheduledTimerWithTimeInterval:.3 target:self selector:#selector(buttonAction:) userInfo:nil repeats:NO];
}
-(IBAction)dragInside:(id)sender {
[self.downTimer invalidate];
[self buttonAction:self];
}
-(void) buttonAction:(id) sender {
if ([sender isKindOfClass:[NSTimer class]]) {
self.touchedDown = YES;
NSLog(#"click down");
}else{
if (! self.touchedDown) {
NSLog(#"Drag");
}
}
}
-(IBAction)touchUpAction:(id)sender {
self.touchedDown = NO;
}
Try this way:
isClicked is property of type BOOL. Set to YES.
- (IBAction)clickButton:(UIButton *)sender { //touch down
if(isClick==YES){
NSLog(#"Click Button");
//do all your stuffs here
}
isClick=YES;
}
- (IBAction)dragInsideButton:(UIButton *)sender {
NSLog(#"Drag Button");
isClick=NO;
}
On top of this you can also implement removeTarget:Action:
Which ever method gets called first set isClick=NO, I expect clickButton is called first in button action.
I got from Two action methods for an UIButton; next track and seek forward:
Change it As per your requirement.
Personally I'd just track the button's state with an integer on your view controller or within a button subclass. If you track what the button is doing you can control what each of the actions do. In your .h file put in some stuff like this:
enum {
MyButtonScanning,
MyButtonStalling,
MyButtonIdle
};
#interface YourClass : UIViewController {
NSInteger buttonModeAt;
}
#property (nonatomic) NSInteger buttonModeAt;
-(IBAction)buttonPushedDown:(id)sender;
-(void)tryScanForward:(id)sender;
-(IBAction)buttonReleasedOutside:(id)sender;
-(IBAction)buttonReleasedInside:(id)sender;
#end
And then in your .m file throw in some of this stuff:
#implementation YourClass
///in your .m file
#synthesize buttonModeAt;
///link this to your button's touch down
-(IBAction)buttonPushedDown:(id)sender {
buttonModeAt = MyButtonStalling;
[self performSelector:#selector(tryScanForward:) withObject:nil afterDelay:1.0];
}
-(void)tryScanForward:(id)sender {
if (buttonModeAt == MyButtonStalling) {
///the button was not released so let's start scanning
buttonModeAt = MyButtonScanning;
////your actual scanning code or a call to it can go here
[self startScanForward];
}
}
////you will link this to the button's touch up outside
-(IBAction)buttonReleasedOutside:(id)sender {
if (buttonModeAt == MyButtonScanning) {
///they released the button and stopped scanning forward
[self stopScanForward];
} else if (buttonModeAt == MyButtonStalling) {
///they released the button before the delay period finished
///but it was outside, so we do nothing
}
self.buttonModeAt = MyButtonIdle;
}
////you will link this to the button's touch up inside
-(IBAction)buttonReleasedInside:(id)sender {
if (buttonModeAt == MyButtonScanning) {
///they released the button and stopped scanning forward
[self stopScanForward];
} else if (buttonModeAt == MyButtonStalling) {
///they released the button before the delay period finished so we skip forward
[self skipForward];
}
self.buttonModeAt = MyButtonIdle;
}
After that just link the button's actions to what I've noted in the comments before the IBactions. I haven't tested this but it should work.
i'm not sure it will work but you can try
- (IBAction)dragInsideButton:(UIButton *)sender {
[sender removeTarget:self forSelector:#selector(clickButton:) forControlEvent:UIControlEventTouchDown];
}

Pass sender of programmatically called segue to destination

Sorry if the title isn't very clear, but hopefully I can elaborate here.
I have a ViewController MatchLineupViewController, which displays 22 buttons to represent rugby players on a team. When the user taps any of these buttons, a modal segue is called programmatically in the following method:
- (IBAction) showSquadSelector:(UIButton *)sender {
[self performSegueWithIdentifier:#"SeguePopupSquad" sender:sender];
}
The modal ViewController which is then displayed is called SquadSelectViewController. It passes back a selected player object to the MatchLineupViewController, which is acting as a delegate. This works perfectly.
However, I want to assign the profile_picture attribute of the returned object to the UIButton that sent the segue in the first place.
EDIT - The returned object is an NSDictionary as shown in the following code:
- (void) selectPlayer:(NSDictionary *)player forButton:(UIButton *)sender {
[sender.imageView setImage:[UIImage imageWithContentsOfFile:[player objectForKey:#"profile_picture"]]];
}
How would I go about doing this? If you require any further code to understand what I am asking, I can provide it.
Many thanks,
Chris
EDIT -
- (IBAction) showSquadSelector:(UIButton *)sender {
[self performSegueWithIdentifier:#"SeguePopupSquad" sender:sender];
}
- (void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([segue.identifier isEqualToString:#"SeguePopupSquad"]) {
SquadSelectViewController *ssvc = (SquadSelectViewController *) segue.destinationViewController;
ssvc.myDelegate = self;
ssvc.senderButton = sender;
}
}
- (void) selectPlayer:(NSDictionary *)player forButton:(UIButton *)sender {
[sender.imageView setImage:[UIImage imageWithContentsOfFile:[player objectForKey:#"profile_picture"]]];
NSLog(#"%#", [player description]);
NSLog(#"%#", [sender description]);
}
You can forward the sender of your showSquadSelector: method to the segue, like this:
[self performSegueWithIdentifier:#"SeguePopupSquad" sender:sender];
The sender of the segue would be the button that triggered the segue, so the code triggered from the segue would know what button has triggered it: your prepareForSegue: would have the correct UIButton. You can now add it to the returned dictionary at a predetermined key (say, #"senderButton") and examine it upon the return from the segue.

Getting Button Tag Value in iPhone

I have made 20 Buttons dynamically, and I got the tag values of all Buttons.
But I need to know how to use that tag values.
I need information on every button pressed with tag values.
So, how do I use those tag values?
You need to set target-action of each button.
[button setTarget:self action:#selector(someMethod:) forControlEvents:UIControlEventTouchUpInside];
Then implement someMethod: like this:
- (void)someMethod:(UIButton *)sender {
if (sender.tag == 1) {
// do action for button with tag 1
} else if (sender.tag == 2) {
// do action for button with tag 2
} // ... and so on
}
Why do you need to use the tag to get the button. You can directly get the buttons reference from its action method.
- (void)onButtonPressed:(UIButton *)button {
// "button" is the button which is pressed
NSLog(#"Pressed Button: %#", button);
// You can still get the tag
int tag = button.tag;
}
I hope you have added the target-action for the button.
[button addTarget:self action:#selector(onButtonPressed:)
forControlEvents:UIControlEventTouchUpInside];
You can get reference to that your buttons using that tags. For example, you've added UIButtons to UIView *mainView. To get reference to that buttons you should write following:
UIButton *buttonWithTag1 = (UIButton *)[mainView viewWithTag:1];
Set the tags like this :
for (createButtonIndex=0; createButtonIndex<buttonsCount; createButtonIndex++)
{
buttonCaps.tag=createButtonIndex;
}
And add the method to trap the tags :-
-(void)buttonsAction:(id)sender
{
UIButton *instanceButton = (UIButton*)sender;
switch(instanceButton.tag)
{
case 1(yourTags):
//Code
break;
case 2:
//Code
break;
}
}
Hope this Helps !!
- (IBAction)buttonPressed:(id)sender {
UIButton selectedButton = (UIButton *)sender;
NSLog(#"Selected button tag is %d%", selectedButton.tag);
}
usefully we use btn tag if You Write One Function For (more than one) Buttons .in action if we want to write separate Action For button at that situvation we use btn tag.it can get two ways
I) case sender.tag
//if we have four buttons Add,mul,sub,div having Same selector and add.tag=10
mul.tag=20,sub.tag=30,div.tag=40;
-(IBAction) dosomthing:(id)sender
{
int x=10;
int y=20;
int result;
if(sender.tag==10)
{
result=x+y;
}else if(sender.tag==20)
{
result=x*y;
}else if(sender.tag==30)
{
result=x-y;
}else if(sender.tag==40)
{
result=x/y;
}
NSLog(#"%i",result);
}
2)Case
UIButton *btn=[self.view viewWithTag:10];
then you got object of add button uyou can Hide It With btn.hidden=YES;
UIButton *btn = (UIButton *)[mainView viewWithTag:button.tag];

Detect which button is pressed with an UIButton Array

I have an UIButton array like this:
#property (nonatomic, retain) IBOutletCollection(UIButton) NSArray *btn_Impact_Collection;
and I have this function:
- (IBAction)impactAction:(id)sender;
In the XIB file I have nine button, each button is connected to btn_Impact_Collection Array with the Referencing Outlet Collection. Moreover the Touch_inside property of each button is connected to the function ImpactAction.
Now, when a button is clicked the ImpactAction function is called, but inside this function, how can i know which button is pressed?
Thanks in advance for the answer!
Cast sender to UIButton class, and that will give you the instance of the clicked button. I don't have Xcode with me but something like:
if ([sender isMemberOfClass:[UIButton class]])
{
UIButton *btn = (UIButton *)sender;
// Then you can reference the title or a tag of the clicked button to do some further conditional logic if you want.
if([btn.currentTitle isEqualToString:#"title of button"])
{
// do something.
}
else if(etc...)
}
Set tags for each button in interface builder (1-9), then say
if ([sender tag] == 1) {
//First button was pressed, react.
}
else if ([sender tag] == 2) {
//Second button was pressed, react.
}
// Etc...
else {
//Last button was pressed, react.
}
And the same for all the others, or you could put it in a switch.
Rather than do a string check on the title (which is slow and can be tedious) you can:
- (void)buttonPressed:(id)sender
{
for( UIButton *button in self.buttonCollection )
{
if( sender == button )
{
// sender is your button (eg. you can access its tag)
}
}
}
Another option.. Cast sender to check if it's a UIButton, then switch sender.tag:
if ([sender isMemberOfClass:[UIButton class]]) {
switch ([sender tag]) {
case 0:
//do stuff for button with tag 0
break;
case 1:
//do stuff for button with tag 1
break;
case 2:
....
break;
default:
break;
}
}

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