In my app, I have a couple of UISlider instances to change various values. The values are displayed right next to the slider, as well as rendered in a 3d space in another visible part of the app.
The 3d part includes some rather heavy calculations, and right now it doesn't seem possible to update it live as the slider changes. That would imply that I'd have to set the slider's continuous property to NO, therefore only getting updates when the slider has finished changing.
I'd prefer to have the displayed value update live, however. Is there a way to have a slider that is continuous (so I can update my value-label in real time) and still sends some kind of message once the user has finished interacting with it? My gut feeling right now is to subclass UISlider and override the touchesEnded: method. Is that feasible?
You can do this with simple target/actions.
Set a target and action for the UIControlEventValueChanged event, and then another target and action for the UIControlEventTouchUpInside event. With the continuous property set to YES, the value changed event will fire as the slider changes value, while the touch up inside event will only fire when the user releases the control.
I just had to do this, so I looked up touch properties, and used the full IBAction header.
This should be a viable alternative for people who want some extra control, though Jas's is definitely easier on the code side.
- (IBAction)itemSlider:(UISlider *)itemSlider withEvent:(UIEvent*)e;
{
UITouch * touch = [e.allTouches anyObject];
if( touch.phase != UITouchPhaseMoved && touch.phase != UITouchPhaseBegan)
{
//The user hasn't ended using the slider yet.
}
}
:D
Also note you should connect the UIControlEventTouchUpOutside event as well in case the user drags his finger out of the control before lifting it.
In Swift 3:
#IBAction func sliderValueChanged(_ slider: UISlider, _ event: UIEvent) {
guard let touch = event.allTouches?.first, touch.phase != .ended else {
// ended
return
}
// not ended yet
}
Related
I have been trying to focus the first button but focus engine takes the third button right below the tab bar as the first item to be focussed. I tried with preferred focus view but found that when i place the buttons in vertical order then preferred takes the preferred view to be focussed but when i placed all the buttons in horizontal plane it always takes the third button.The other approach i can think of if Focus Guide but i wonder how that will work in this scenario?
override weak var preferredFocusedView: UIView? {
get {
return thrirdButton
}
}
It happens because focus engine takes the nearest possible focus element as 1st element as you can see from the picture attached.I have attached the context screenshot for the view controller. Any help or clue to solve this will be appreciated.
Solution :
We need to add focus guide just above button 3 and redirect it to button one when the focus guide is focussed.
private var focusGuide = UIFocusGuide()
self.view.addLayoutGuide(focusGuide)
self.focusGuide.bottomAnchor.constraintEqualToAnchor(self.button3.topAnchor).active = true
self.focusGuide.leftAnchor.constraintEqualToAnchor(self.button3.leftAnchor).active = true
// Width and height
self.focusGuide.widthAnchor.constraintEqualToAnchor(self.button3.widthAnchor).active = true
self.focusGuide.heightAnchor.constraintEqualToAnchor(self.button3.heightAnchor).active = true
focusGuide.centerXAnchor.constraintEqualToAnchor(self.button3.centerXAnchor).active = true
override func didUpdateFocusInContext(context: UIFocusUpdateContext, withAnimationCoordinator coordinator: UIFocusAnimationCoordinator) {
self.focusGuide.preferredFocusedView = button1
}
Try adding a UIFocusGuide just above the button rows. In that case, before reaching the button, it will hit your focus guide in which you can redirect the preferredFocusedView to that particular button. The code to redirect is to be done by overriding didUpdateFocusInContext method.
Assuming you have setup the focus guide in viewDidload, the following is a sample,
override func didUpdateFocusInContext(context: UIFocusUpdateContext, withAnimationCoordinator coordinator: UIFocusAnimationCoordinator) {
super.didUpdateFocusInContext(context, withAnimationCoordinator: coordinator)
self.focusGuide.preferredFocusedView = self.mypreferredbutton
}
TO initialise a focus guide ( Do the addition of guide to view in viewDidLoad)
var focusGuide = UIFocusGuide()
self.view.addLayoutGuide(self.sidefocusGuide)
self.focusGuide.leftAnchor.constraintEqualToAnchor(self.placerLabel.leftAnchor).active = true
self.focusGuide.rightAnchor.constraintEqualToAnchor(self.placerLabel.rightAnchor).active = true
self.focusGuide.topAnchor.constraintEqualToAnchor(self.audioTable.topAnchor).active = true
I too faced a similar issue but somehow able to do it through this. The preferredFocusedView approach will also work, but you have to do lot of circus by updating some reference variable and then calling setneedsfocusupdate for that view. Try the focus guide way. Hope it helps.
EDITED:
I have added code how to setup the guide. In this case I have put the guide on the right side of my view. So, whenever your focus hits the guide, it redirects to the preferredfocusguide view that you want the focus to go to in the didUpdateFocusInContext. "There is only one view in focus at anytime.", remember thes ? So, the moment it hits the guide, the overriden method gets hit which in turn moves your focus to the guide's preferred view. For examples, you can refer to Apple's UIKitCatlog app for tvOS and here is one link explaining the same.
The best way to give the initial focus to your preferred view is by using preferredFocusEnivronments.
override var preferredFocusEnvironments: [UIFocusEnvironment] {
return [firstButton]
}
preferredFocusEnvironments will be called before didUpdateFocus, that way you can inform the system, where you want the focus to be redirected.
The project have some views with different buttons. When I hide a view and show the other view, I can't get the focus on my button.
I think is related to setNeedsFocusUpdate. I have read the Apple doc. There is not any example.
Does anyone know how to do it and put an example (Objective C)?
You need to override preferredFocusedView, and when you are hiding one view and showing there call this method setNeedsFocusUpdate, your preferredFocusedView implementation should be something like this
- (UIView *)preferredFocusedView
{
// Add your logic here, it could be more complicated then what is below
if (view1.hidden)
{
return _button;
}
else
{
return _button2
}
}
And if you want to make custom view get focus, override canBecomeFocused method and return true
Edit
You can use add a breakpoint and execute this command po [buttonYouWantToFocus _whyIsThisViewNotFocusable] it will tell you why its not focusable.
If you are adding a sub view programmatically, maybe this is what you want:
- (UIView *)preferredFocusedView {
return [view1 preferredFocusedView];
}
I realize your question is specific to Objective-C but here is a way to solve for this in Swift. You need to override the preferredFocusedView property.
override var preferredFocusedView: UIView? {
guard primaryView.hidden == false else {
return secondaryView
}
return primaryView
}
Then just call setNeedsFocusUpdate() whenever an event happens that causes your views to be hidden. Hope this helps...
Another option (if you don't want to use preferredFocusedView) is, instead of setting your view to be hidden, simply remove it from it's superview, like so:
myView.removeFromSuperview()
This automatically takes the focus away from the button that is removed and gives it to another one that is still on screen.
I have an object I want to drag around the screen with the mouse in Processing. I set acquired to true on mouse down over the object, and to false on mouse up, thus:
void mousePressed() {
if (overThing()) {
acquired = true;
}
}
void mouseReleased() {
acquired = false;
}
I then query acquired in my update(), and drag the object if it is true.
void update() {
\\ other stuff...
if (acquired) {
\\ drag thing code ...
}
}
This all works fine in Processing. mouseReleased() gets called whether I release the mouse inside or outside the active window.
However, when I move the code to Chrome, using processing.js (v1.4.8), mouseReleased() is not called if I release the mouse outside the canvas (whether the mouse is still over the web page, or outside the browser window). So when I return the (now unclicked) mouse to the canvas, the object is still getting dragged around.
I tried including a test of mousePressed in update(), but that also returns true in these circumstances.
Any help on what I need to do to make mouse state changes outside the canvas visible with processing.js?
I don't know about Processing specifically, but releasing mouse buttons outside a widget is a common issue in GUI development.
I suspect that you have no way of knowing the precise time when the mouse is released outside the widget, but you do have two options:
Set acquired = false in mouseOut(), as #Kevin suggests.
I assume there is some type of mouseEntered() method in Processing, and also some way of knowing if the mouse button is currently pressed (either a global variable, or an event object passed to mouseEntered()). You can catch the mouse entered event, check if the mouse has been released, and set acquired = false then.
Like so:
void mouseEntered() {
if (mouse button is pressed) {
acquired = false;
}
}
Edit: From your comments, #Susan, it seems like there is a bug in processing.js, where mousePressed is not set to false if the mouse button is released outside the canvas. One thing pointing to this being a bug is that the mouse movement example on the processing website also shows this behaviour.
Depending upon how much control you have over the website this is going on, and how much effort you want to go to, you could fix the bug yourself by writing some javascript (separate from your processing code):
Define a mouseUp() event on the page <body>, to catch all mouse release events on the page.
In the mouseUp() event, check if the event comes from your Processing control. (There is probably an event object passed to the mouseUp() function, and you might have to give your Processing control an ID to identify it)
If the event doesn't come from your Processing control, then fire a mouseUp event yourself, on the Processing control. This should (hopefully!) trigger a mouse event inside your Processing code.
I'm not sure what Processing will make of the mouse (x,y) position being outside its control when it handles the event you send it. You might want to set a flag on the event object (assuming you can add extra data to the event object) to say "don't use the (x,y) position of this event - it's outside the control".
Edit2: It was easier than I thought! Here is the JavaScript code to detect the mouse being released outside of the Processing canvas and send the mouseReleased event to the canvas. I've tested it on the mouse movement example from the Processing website, and it fixes the bug.
It uses jQuery (although it could be re-written to not use jQuery), and it assumes your Processing canvas has the ID "processingCanvas":
$(':not(processingCanvas)').mouseup(function(){
Processing.getInstanceById('processingCanvas').mouseReleased();
});
To use this code, include it anywhere in your page (in a JavaScript file or in <script> tags) and make sure you have the jQuery library included before this code.
The Processing object allows JavaScript to call any functions defined in your Processing code. Here I've used it to call Processing's built in mouseReleased() function, but if you wanted to call a custom function to handle the mouse-released-outside state differently, then you could.
You should use the mouseOut() function to detect when the mouse leaves the sketch:
void mouseOut() {
acquired = false;
}
More info in the reference here.
I try to implement a custom ContextMenu in a LongListSelector.
I'm not using the ContextMenu from Microsoft.Phone.Controls.Toolkit, it's basically the same as in the Rowi App:
(source: hiddenpineapple.com)
Approach 1
My list item toggles a VisualState on hold and an overlay is shown with controls in it.
The problem
I can't find a way to go back to the default state when the user clicks outside of the list item (as in the default ContextMenu).
Approach 2
I've implemented a custom template for the toolkit ContextMenu which looks exactly the same. I had to move its margin top to -itemHeight, as by default it is below the item.
The problem
The problem with this solution is, that it automatically closes itself when opening and I couldn't figure out how to avoid this.
Another problem was that it didn't work well with TiltEffect.IsTiltEnabled from the Toolkit (visual problems).
I need your help
Any suggestions on how to get this working?
Answer
Thanks to Cheese, now I know how to properly close the menu when the user clicks outside.
His suggestion was to get the coordinates of a Tap event on the current page, and check if it's inside the menu. When not, close the menu.
So I added a Tap listener to the page when the menu opens, and removed it when the menu closes. From the page listener I got the event coordinates and could check if it's inside the control which holds the menu (same size and position). I received the position of the control with Point leftUpperPoint = control.TransformToVisual(page).Transform(new Point(0, 0)) and the rightLowerPoint by adding the ActualWidth and ActualHeight.
But then I realized:
Why should I even calculate if the tap is inside the menu? I always want to close the menu when the user taps anywhere on the screen. If it's outside, yes. If it's on a menu button, yes.
Another modification I made was to listen for MouseLeftButtonDown instead of Tap as it also triggers when the user swipes.
So I removed this code and came up with the following:
private void ToggleMenu(object sender, System.Windows.Input.GestureEventArgs e)
{
PhoneApplicationFrame frame = ((PhoneApplicationFrame)Application.Current.RootVisual);
VisualState state = this.States.CurrentState;
if (state == null || state.Name == "DefaultState")
{
frame.MouseLeftButtonDown += MouseDownDelegate;
this.State = "MenuState";
}
else
{
frame.MouseLeftButtonDown -= MouseDownDelegate;
this.State = "DefaultState";
}
}
private void MouseDownDelegate(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
ToggleMenu(sender, null);
}
This works perfectly!
Thanks to Cheese for the hint.
Something like this by #denniscode http://dotnet.dzone.com/articles/rowi-show-tap-menu
Approach 1 problem
The best solution would be:
Get the menus coordinates, when user makes a tap - you check are tap coordinates on menu or not, if not - dissmiss - simple.
Approach 2 problem
I guess you had some button in a corner and when you tapped on it - nothing happened? And when you dissmissed the Tilt all worked. It seems that tilt works faster than a click, so, tilt changes the button coordinates, and device thiks you have missed/or dragged off
You can use what #ScottIsAFool suggested and maybe create another Dependency Property on your TapMenu control of type UIElement named CloseWhenTappedElement and automatically listen for Tap events inside your control once set. For example
<Grid x:Name="TapArea"/>
<TapMenu CloseWhenTappedElement="{Binding ElementName=TapArea"}/>
I am currently using pagination in a UIScrollView, and for tracking any page change I use;
-(void) scrollViewWillBeginDecelerating:(UIScrollView *)scrollView
{
if (_previousContentOffset > _pageContainer.contentOffset.x)
{
NSLog(#"Less");
_currentPageIdx--;
}
else if (_previousContentOffset < _pageContainer.contentOffset.x)
{
_currentPageIdx++;
NSLog(#"More");
}
}
Now the problem is that, this method isn't tracking the touch fast enough, so when this method is called, the user can be 3 pages along if he/she is paging like a maniac. I tried setting
_pageContainer.decelerationRate = UIScrollViewDecelerationRateFast;
but that didn't make the tracking much faster.
Is there a solution or alternative for this?
Use scrollViewDidScroll: instead. It is being called continuously while the user scrolls.