I have an slide show application. There is a UIView on main screen, I want when someone slide his fingers horizontally it moves to next screen.
What this event is called? (slide fingers horizontally/vertically)
How can i detect this event? Want to call a method xyz on this event
You might be looking for a Page Control.
If not, then you can use touchesMoved:withEvent: to detect the drag event. In this event handler you need to compare the coordinates to detect whether it is moving horizontally or vertically.
Related
I have an application that has a canvas (NSView) where a user can drag an element around. When the mouse leaves the edge of that view it becomes a drag operation.
What I would like to do is when the mouse entered the originating view again it would cancel the operation and would automatically start the move within the canvas again.
I can figure out the second part I just need to figure out how to force a drag and drop to cancel. I need to do this somehow from draggingEntered: so before the mouse is even released.
Make your canvas view respond to drags as well. Initially all its <NSDraggingDestionation> protocol methods would just return “no, do nothing”, but if you start a drag from within the canvas you’d keep track of that, and once the drag leaves and comes back your NSDraggingDestionation methods would return, “Ok, we accept, drag is over, don’t bother animating.”
Then you could continue tracking locally. Like, assuming your canvas had called:
- (void)dragImage:(NSImage *)anImage at:(NSPoint)viewLocation offset:(NSSize)initialOffset event:(NSEvent *)event pasteboard:(NSPasteboard *)pboard source:(id)sourceObj slideBack:(BOOL)slideFlag;
That method would then return control to your canvas
I am using a UIPageViewController to display certain content. I want to be able to display additional content when the user pulls down on the page using a UIPanGestureRecognizer. I can't seem to figure out what I should add my gesture recognizer to such that it does not cancel any of the pageviewcontroller's actions.
One of the apps I worked on has functionality similar to this. It shows a full-screen UIPageViewController, but if the user drags down on a ribbon on the top right corner, it will slide the whole thing down to reveal a view behind (for settings and other stuff).
I think your problem is that the built-in gesture recognizers are for the page turns. So what you'd want to do is either have something to drag on (such as the ribbon on the top left in my app) that will have its own gestures. OR you can iterate through the gesture recognizers that are assigned to UIPageViewController and get the one that matches the PanGesture, then override it with your own functionality to either delegate the event to the UIPageViewController or do the slide down, based on the type of pan.
Hope that helps.
I've encountered a problem where my button should remain "pressed down" while it shows popover called from it. Popover is selector for some filter and filter is shown on button itself. When I tap on it and it shows popover it becomes deselected no matter what.
I think I have to redefine it's behavior on touch event and make it respond not to standart touch up inside. Then I wondered what are other events responsible for? But I couldn't find events list in iOS library and in StackOverflow are only questions about incorrect behavior of touch up inside or touch down.
So what's the difference betweeen touch events?
touch cancel - when you touch button but move your finger away and
it remains deselected?
touch down - right on tap.
touch down repeat ??
touch drag enter ??
touch drag exit ??
touch drag inside ??
touch drag outside ??
touch up inside - when you tap and release button remaining in it's
bounds . It changes UIButtons state to Normal.
touch up outside - when you tap and release button leaving it's
bounds ?
other IBActions are not sent by UIButton, right?
Also how those events change UIButton's appearance? Like highlighted or selected?
I'd appreciate a link on good article about IBActions, because I couldn't find it.
From Apple's doc for UIControlEvents:
UIControlEventTouchCancel
A system event canceling the current touches for the control.
UIControlEventTouchDown
A touch-down event in the control.
UIControlEventTouchDownRepeat
A repeated touch-down event in the control; for this event the value of the UITouch tapCount method is greater than one.
UIControlEventTouchDragEnter
An event where a finger is dragged into the bounds of the control.
UIControlEventTouchDragExit
An event where a finger is dragged from within a control to outside its bounds.
UIControlEventTouchDragInside
An event where a finger is dragged inside the bounds of the control.
UIControlEventTouchDragOutside
An event where a finger is dragged just outside the bounds of the control.
UIControlEventTouchUpInside
A touch-up event in the control where the finger is inside the bounds of the control.
UIControlEventTouchUpOutside
A touch-up event in the control where the finger is outside the bounds of the control.
Listed in, what I would consider, order of common use/likelihood of occurrence for a normal button:
UIControlEventTouchDown: The user tapped the button. This fires on the finger/stylus making contact.
UIControlEventTouchUpInside: The user tapped the button. This fires on the finger/stylus contact pulled back away from the screen.
Useful for sliders and drag events like moving a component around. The below are in order of occurrence:
UIControlEventTouchDragInside: Triggered as the finger drags into the button area.
UIControlEventTouchDragExit: Triggered during a drag motion. It is called only once, as the users finger/stylus leaves the bounds of the button.
UIControlEventTouchDragOutside: Triggered during a drag motion, after 'UIControlEventTouchDragExit', and is called continuously, as long as the original touch continues.
UIControlEventTouchUpOutside: This is simply the finger/stylus being lifted BUT only if the finger/stylus is no longer within the bounds of the button. The important thing (and probably obviously) to call out is that the touch had to have been within the button at some point to associate this event with the button.
Note: My understanding is that the above can be helpful for:
Sliders: as you might expect the touch may have been intentional but because of the quick swipe action, their finger movement may be sloppy and lift up outside of the slider area.
Moving components around, as when you push things around a screen you want the movement to happen when the finger/stylus touches the border of the component/object.
Other events:
UIControlEventTouchCancel: Something out of the user's control is cancelling their touch action. Think of this as something "going wrong" on the phone side of things.
UIControlEventTouchDownRepeat: Want to detect when your user is mad and tapping a button furiously? Want to detect if they're still in Windows mode and are trying to "double click"? Or maybe you designed a button to do something different if they tap twice. This event helps with all of those!
References:
SO 1: Dif between UIControlEventTouchDragOutside and UIControlEventTouchDragExit
SO 2: What is UIControlEventTouchCancel?
I have a UIView within a UIScrollView. When i want to simulate the drag event on the UIView, swipe event on the UIScrollView is being triggered.
As per the documentation , there isn't much of a difference between swipe and drag.
Swipe
1- Place the pointer at the start position.
2- Hold the mouse button.
3- Move the pointer in the swipe direction and release the mouse button.
Drag
1- Place the pointer at the start position.
2- Hold down the mouse button.
3- Move the pointer in the drag direction.
On an ipad I can use two fingers two swipe and one finger to drag. Now, how do i go about doing something similar on the simulator; drag instead of a swipe?
Edit 1:
I should have been clearer first up. Anyway, my problem is that the mouse drag is firing the swipe instead of drag, thereby scrolling the scroll view instead of passing on the drag event to the UIView contained by the scroll view.
I am on macbook pro. Two-finger swipe on the touchpad is being ignored. Touch and drag is causing the same thing as mouse-drag.
Thanks
See Jeff LaMarche's quick note on how to do this. It's documented in the same page you're reading, but Jeff's explanation is clearer.
If you want to simulate a two-finger gesture in the iPhone simulator, hold down the option key. You will get two dots on the screen instead of one. The two dots will default to pinching - if you bring the dot closer to the center of the screen, the other dot comes toward the center, making it easy to simulate a pinch in or pinch out.
If you want to do a different two-finger gesture, get the two dots the distance apart that you want them to be, then hold down the shift key, while still holding down the option key. That will lock the position of the two finger presses together so you can do, for example, a two-finger swipe.
see this documentation below:
iOS Simulator User Guide
Just use the mouse to drag the view, aka, left click the view then move the mouse
I ended up disabling the scrolling from the UI and added two buttons to scroll the scroll view. Since this is a work around only for the emulator, I have used #ifndef to hide the buttons while building for the device.
I have two canvases located to each other. One is supposed to be a kind of workspace you can add items to, select and rearange them. The other one is just a property view.
What I want to do is to be able to draw a rectrangle on the workspace. As long as the user holds down the mouse button the rectangle will show up. If he releases the button all items that are beneath the rectangle will be selected. This currently works good with the MouseDown, MouseStillDown und MouseUp events. I'm drawing another rectangle shaed canvas on the workspace which will be transformed on every MouseStillDown event and the selection will occur on the MouseUp event. My problem is, that if the user hold down the mouse button and moves it to the property canvas and then releases the button the MouseUp event from the workspace isn't called. Neither is the one from the property since it's missing a MouseDown event. So if the user releases the button there the selection won't work and the rectangle stays in the workspace.
Is there an oppurtunity to somehow avoid this? Or is there a better way to determine the area the user selected with it's mouse while holding down the left mouse button?