I'm programming a King Chess game on the iPhone. When the user touches a square on the screen, I want to know which square was selected.
I am using UIImageViews to show squares on the screen.
UIImageview would not be feasible in your scenario. You can use UIButton with customtype and assign image to that button. So it looks like button but you can add target and you know which square touch/pressed.
Hope this help.
in touchesEnded: method , u can get the position of ur touch.
Then , u go thru all the image views (squares) , comparing their frame positions using CGRectIntersectsRect and find which square is touched.
Related
I have to make view where there will be multiple curved or irregular shaped imageview. Now when i will touch a UIImageview then it will import image from photo gallery.For example: Suppose
I have an UIView with background image.
On that view i have 3 irregular shaped UIImageview.every UIImageview is attached with each other.
Now suppose i have touch in the first UIImageview then it will take an image from photo gallery.
When i have imported the image then that image will be as the background image of the UIImageview.
I have to make sure that if my UIImageviewis smaller then its background image then i will able to move the image or rotate the image or scale or zoom the image to adjust the image according to the size of UIImageview.
How can i do that whole process??? any help by link,source code,tutorial or anything else will be cordially appreciable.
Basically my first priority is that how can i make those irregular shaped UIImageView pro-grammatically.
IF ANY FURTHER QUERY TO ASK THEN PLEASE DON'T HESITATE.
Thanks In Advance
The one way of doing this is as follows:
Subclass from UIImageView set touchesBegan methods for each UIImageView for import image, setting on background and whatever you want to do on touch.
What does 'attached' mean? If all of them should move together, then, again, you have to deal with it in touchesBegan methods, sending messages like 'Hey views, i've moved on this vector:[vector], please do it too'.
In pt. 3.2 i didn't get your point. :( You can set in UIImageView subclass self.contentMode = UIViewContentModeScaleAspectFit or UIViewContentModeScaleToFill, so its image will always fit the view.
About irregular shape, did you read links below? I suppose there's not an super easy way to do it :(
http://www.iphonedevsdk.com/forum/iphone-sdk-development/76923-hittest-collision-for-irregular-shaped-uiviews.html
Draggable UIImageView Partially Transparent & Irregular Shaped
Simple way of using irregular shaped buttons
I'm making a Schedule App for Cocoa Touch and I need to be able to select a time interval just by touching the screen. I mean, the user must be able to select with its fingers a time interval within the "ScheduleView" and then Add an event.
I was thinking of making some kind of rectangular selection, similar to the one that everyone can do in Windows Desktop, but i don't know how to detect multiple touches, neither how to draw the selection rectangle. Can anyone help me?
P.S: The "ScheduleView" it's a UIView, not a UITableView
You'll need to add a UIGestureRecognizer to your view. You can detect touches as a delegate, and this case will probably do best with a UIPanGestureRecognizer. You'll set the delegate to be yourself and draw the box within -(void)panGestureMoveAround:(UIPanGestureRecognizer *)gesture Here is a tutorial.
To draw the box, you could manually draw into the view but it may be easier to reshape a UIView on top and manipulate its border width and color like this SO question.
There are a series UIViews arranged very close.
alt text http://www.mobilepanda.com/questiontouch.png
I hope when my finger touches some of them, my app can detect which UIView touched.
Maybe one or two or three.(because the displayed parts of each UIView are too thin).
I hope to get the middle x value of the touch, then spread the UIView where the middle x value locates and the UIViews near it.
alt text http://www.mobilepanda.com/questiontouch1.png
My way is put a transparent UIView over all these UIView to detect the touch event.
I am not sure if this is ok? or there is any better solution.(for example, make each UIView has the capability to detect the touch, mix and decide which UIView is touched.
Welcome any comment
Thanks
interdev
You don't need to do all that. The OS will decide what the center point of the finger touch is and send an event with the touch x,y coordinates to the correct view. If you make them UIButton's (a subclass of UIView) instead of UIView's the OS will do all the work for you. All you have to do is attach callbacks to each button to the functions you want called for various events (like touchUpInside, touchDownInside, etc).
I have a view that is moving. The view is sometimes on and sometimes off screen - it is twice the width of the screen.
In this view, there are buttons that I need to be able to click.
I've tried doing this in many ways already - using pure buttons
using touches began on UIView
I'm doing the animation using a CGPath in core animation
Any help would be most appreciated
Thanks
Whether the view is moving or not should irrelevent to the touch detection. If you have a UIButton object and are handling the UIEventControlTouchUpInside (forgot the exact name) event , it should be called when it sees a touch. Is that not working for you?
How can I get a non-rectangular shaped button?
For example I do have a PNG image with alpha transparency.
How can I set the shape of a button to this image without the transparent color.
Like the others say you should have a reasonable surface for registering touch events, but I'm sure you know that and have your reasons so I'll just tell you how I did it:
I needed to do this not so long ago and what I did is what Sixten Otto just suggested. There are some hints in my original question ("UPDATE" section) for getting the alpha value for your image at a certain point:
How to create a transparent window with non-rectangular buttons?
Edit: I suggest subclassing UIControl in the example below but if you don't need any special behavior on your button apart from the "non-rectangleness" of it then just subclassing a borderless UIButton set up with your PNG will do the job and require less work. You have more control on the control's behavior by subclassing UIControl and doing it the "hard way" though.
I would suggest that you subclass UIControl and override the touch event methods, then check for alpha under the tapped point and not handle the event if alpha == 0. For drawing you override drawRect: and use the NSImage's drawInRect:fromRec:operation:fraction: method in there to draw your image in the control's frame.
First you need to load the image and get a bitmap representation of it:
buttonImage = [NSImage imageNamed:#"myButtonImage"];
buttonImageRep = [[buttonImage representations] objectAtIndex:0];
Then you can draw it to the control's view: (where stateImage is a pointer to the image that must be drawn depending on if the button is pressed or not)
- (void)drawRect:(NSRect)aRect {
[stateImage drawInRect:[self bounds] fromRect:NSMakeRect(0.0,0.0,[buttonImage size].width,[buttonImage size].height)
operation:NSCompositeSourceOver fraction:1.0];
}
At this point you have drawn your button with your png image. You can override the touch event methods and handle the event if the alpha is not 0:
NSColor *colorUnderMouse = [buttonImageRep colorAtX:mouse.x y:mouse.y];
float alpha = [colorUnderMouse alphaComponent];
That's what I did and it works wonderfully. Hope this helps!
N.B: My example is for the Mac but it should also work on the iPhone, maybe with some slight modifications.
It sounds like you are looking to have the clickable area of the button exactly match the PNG you are using.
If that is what you are looking for, I would firstly say to not do that. The iPhone is pressed using a finger, which generally doesn't have the accuracy to distinguish such a small region.
However if you are stuck on the idea, then the solution is to not use buttons at all, instead handle the click in a parent frame and manually interpret the X/Y value of the click to determine if it is in some bounding region (In the case of a rounded edge button, would likely consist of oring the result of checking 4 circles and 2 rectangles)
Edit:
Realizing part of your original question, I noticed you mentioned you wanted to handle the function automatically based on the Alpha channel. While I would recommend my method of bounding regions, you could in theory accomplish this by sampling the PNG to test the Alpha channel at a value offset by the origin of the button. Potentially even doing this in a normal button's click event.
Rectangular buttons are a button type, you can use the custom button type and assign an image to get rid of the rectangular edges of the button...heres a reference to button types http://developer.apple.com/iphone/library/documentation/UIKit/Reference/UIButton_Class/UIButton/UIButton.html#//apple_ref/doc/c_ref/UIButtonType and to UIButton http://developer.apple.com/iphone/library/documentation/UIKit/Reference/UIButton_Class/UIButton/UIButton.html
As Guvante says, it's really not a good idea to rely on precision touches. Apple, for instance, recommends that controls be at least 44px across.
I'd recommend using a UIButton of type UIButtonTypeCustom, set the button's image to your PNG, and register for touch events (see here for more on event handling). Then, in your action method, you can get the coordinates of the touch out of the event, and test those coordinates against the alpha of your image to see whether you should treat it as a "real" touch or not.
Another option could be to split your button up into multiple, rectangular parts.
#Form right about using 'drawRect' to implement custom shape for button.
But better method to exam touch inside or not inside button is using of
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event;
You can create your button transparent for touches in some parts.
If you can't use custom image for button (for example if you draw text on the button) you can use new method to draw subviews hierarchy into a image:
- (BOOL)drawViewHierarchyInRect:(CGRect)rect afterScreenUpdates:(BOOL)afterUpdates;