MonoTouch tracking movement over controls - xamarin.ios

I have a simple iPhone app with a simple view and a custom view as a child. The child is just a square painted on the main view.
I need to track a touch event that enters this child view but from a touch that started outside the view.
What I've tried so far is to add the TouchesBegin/TouchesMoved events to the parent view. Also tried to add the to the child controls directly but that doesn't track any touches that are not initiated within that control.
The questions are:
a) can I get the control from Position somehow?
b) is this the best way doing this, or is there another way?
Again, I include this video of GamePlay for the game I'm trying to port (on my spare time). It's not a promotion attempt but illustrates what I'm trying to accomplish. I wrote the Win8 and WP7 version of the game so I'm not trying to copy another persons work here. :) Don't watch it if you don't want to know what game it is. The question is still valid without watching this.
http://www.youtube.com/watch?v=13IczvA7Ipo
Thanks
// Johan

I stumbled on the answer myself. In the parent I override TouchesMoved (and Begin and Ended not shown here).
I then iterate the subviews and chech if it's the view I'm looking for by type and then check if the Frame contains the point. The code below is just concept of course.
public override void TouchesMoved (NSSet touches, UIEvent evt)
{
base.TouchesMoved (touches, evt);
UITouch touch = touches.AnyObject as UITouch;
if (touch != null) {
var rp = touch.LocationInView (touch.View);
foreach(var sv in this.View.Subviews)
{
if(!(sv is LetterControl))
continue;
if(sv.Frame.Contains (rp))
{
Console.WriteLine("LetterControl found");
}
}
}
}

Related

Warn the user that he is about to loose his change in Edit view when leaving to view to another in GWT

I want to prevent the user that he will loose his changes in an EditView when changing the view to another.
I use MVP4G in my project and the project is divided as mvp's structure (one package for the template another one for views ..) is there any solution to detect the EditView in the eventBus. or detect the current View shown to user
Thanks in advance
Thanks to the Navigation Event feature in mvp4g, the presenter will get control before the view changes. At this point the presenter can decide if the navigation will be done or not. This is the correct place in a mvp4g application to save your data.
First zu have to mark all events in the eventbus that will change your view with:
#Event(..., navigationEvent = true)
void goToPage1();
Next your presenters have to implement the NavigationConfirmationInterface and the requires confirm-method:
public class Presenter extends ... implements NavigationConfirmationInterface {
public void confirm(NavigationEventCommand event) {
//pseudo method to verify if the view has changed
if (isViewModified(){
//Window shouldn't be used inside a presenter
//this is just to give a simple example
if (Window.confirm("Are you sure you want to leave?")){
event.fireEvent();
}
} else {
event.fireEvent();
}
}
}
And the last thing to do, is to set the presenter of the current view to the confirmation presenter by calling:
event.fireEvent(false);
This is usually done when the presenter gets control.
You will find the documentation here:
https://github.com/FrankHossfeld/mvp4g/wiki/03.-Defining-EventBus#navigation-event
Thanks to MVP4G's team including El Hoss who gives me a hint to check the MVP4G's blog.. I've solved my problem by following this example
http://mvp4g.blogspot.com/2011/06/navigation-control.html

How do I restrict keyboard focus to controls within a Node?

I'm trying to implement a reusable method for displaying a node as a lightweight dialog. The node is added to the top of a StackPane while the background is then blurred. There are 2 problems:
1) Controls in the background node of the stackpane are still able to receive focus.
2) How do I give focus to the top-level node. I know there is a requestFocus method on Node, but I need to give it to a control nested within the node. Since this is intended to be a reusable method, I can't reference the controls directly.
(if I can sidestep the whole problem by finding an existing implementation, that would be best, but I haven't found a 3rd party solution yet)
Thanks
For:
1) 3 alternative suggestions,
a- Add a key event handler to the dialogbox pane to catch the Tab key pressings
dialogbox.addEventFilter(KeyEvent.KEY_PRESSED, new EventHandler<KeyEvent>() {
#Override
public void handle(javafx.scene.input.KeyEvent event) {
if (event.getCode() == KeyCode.TAB) {
System.out.println("TAB pressed");
event.consume(); // do nothing
}
}
});
b- Temporarily disable all children of the main StackPane except the lastly added dialogbox child.
// Assuming dialogbox is at last in the children list
for(int i=0; i<mainPane.getChildren().size()-1; i++){
// Disabling will propagate to sub children recursively
mainPane.getChildren().get(i).setDisable(true);
}
c- Same as b but manually disable focusing to controls by node.setFocusTraversable(false) (spot kick). Surely this will not be your choice..
2) Tell the dialogbox which node should take the focus after the dialog is shown (through constructor or setter method).
// init dialogbox and show it then
dialogbox.setFocusTo(node_in_dialogbox);

MonoTouch.Dialog: Dismissing keyboard by touching anywhere in DialogViewController

NOTE: There are two similar SO questions (1) (2), but neither of them provides an answer.
TL;DR: How can one dismiss the keyboard in a MonoTouch.Dialog by letting the user touch any empty space in the view?
I'm writing an app using MonoTouch.Dialog and a UITabBarController. One of my tabs is "Settings"...
When the user starts typing, the keyboard obstructs the tabbar...
Using MonoTouch.Dialog, the only way to dismiss the keyboard is to go to the last field and press the "return" key. Considering the fact that the user cannot press any tab until the keyboard is gone, I would like a better way to do it. Namely, to dismiss if the user taps anywhere else on the screen.
Without MonoTouch.Dialog, it's a snap: simply override TouchesBegan and call EndEditing. But this doesn't work with MT.D. I've tried subclassing DialogViewController and overriding TouchesBegan there, but it doesn't work. I'm currently at a loss.
Or, I wonder, would I be better off ditching the tabbar so I can use a UINavigationController with a "Back" button on top, which won't be hidden by the keyboard?
I suggest you use a tap gesture recognizer that will not cause interference with the TableView event handlers:
var tap = new UITapGestureRecognizer ();
tap.AddTarget (() => dvc.View.EndEditing (true));
dvc.View.AddGestureRecognizer (tap);
tap.CancelsTouchesInView = false;
You missed my question about it also: Can the keyboard be dismissed by touching outside of the cell in MonoTouch.Dialog?
:-)
This is my #1 feature request for MonoTouch.Dialog.
To answer your question: No. It is not possible. I have searched and asked around and have not found any answers.
I assume because it is just a sectioned (grouped) table and if it wasn't sectioned, there wouldn't be any spot to click. However, that is just my speculation.
I wish that miguel or someone that works on monotouch would answer this and say if it is even possible. Possibly a future enhancement?
I figured out a workaround that satisfies me well enough, so I'm answering my own question.
// I already had this code to set up the dialog view controller.
var bc = new BindingContext (this, settings, "Settings");
var dvc = new DialogViewController (bc.Root, false);
// **** ADD THIS ****
dvc.TableView.DraggingStarted += (sender, e) => {
dvc.View.EndEditing (true);
};
This will dismiss the keyboard whenever the user drags the view a little bit. There's no touch event I could find associated with the tableview, so this is the next best thing. I'd welcome any other ideas. Cheers!
One workaround to use the dragging gesture instead of the tap as proposed (that do not interfere with the table view gestures) is to override MonoTouch.Dialog.DialogViewController.SizingSource (or MonoTouch.Dialog.DialogViewController.Source if you don't want uneven rows) and give it to the DialogViewController. I don't know if it is very clean or safe.
public class CustomTableViewSource : MonoTouch.Dialog.DialogViewController.SizingSource
{
public CustomTableViewSource(MonoTouch.Dialog.DialogViewController dvc) : base(dvc)
{
}
public override void DraggingStarted(UIScrollView scrollView)
{
base.DraggingStarted(scrollView);
if (scrollView != null)
{
scrollView.EndEditing(true);
}
}
}

Issue with Map view delegate method 'mapView:regionDidChange:' do not call

while using map view in my application some times MKMapKit delegate method 'mapView: regionDidChange' do not call.
Its happens only when I drag the map. but when i zoom in or Zoom out Its working perfectly. So its create issue related to place new annotations on map while dragging the map.
I have do this code in mapView:regionDidChange:
int j=0;
-(void) mapView:(MKMapView *)mapsView regionDidChangeAnimated:(BOOL)animated{
zoomLevel = self.mapView.region.span.latitudeDelta;
if (![appDelegate internetConnected]){
return;
}
if (appDelegate.isMapViewRegionChanged) {
if (j==0) {
j++;
return;
}else{
j=0;
appDelegate.isMapViewRegionChanged = FALSE;
return;
}
}
[self callGetMapViewWithObject:nil];
}
/*
first boolean is to check Internet connection.
[appDelegate internetConnected]
Second condition is to return when we navigate from any view controller too map View controller.
appDelegate.isMapViewRegionChanged
Third is a method to place new annotations.
[self callGetMapViewWithObject:nil];
*/
I checked all conditions and booleans but my coding is not reason for this bug.
so may be its related to region did change method.
So while using my app with map, 20% of time its behave like Ideal(method do not call).
can some one help me out with this.
Thank you in advance.
EDIT It broke randomly, so I now call the function again (undoing what I said below), no changes extra... and um, it works. I feel like I'm flipping a coin.
I just had this happen because I have a subclassed MKMapView. I don't know if you're subclassing this or not, but for some reason Apple's super functions, eg: -(void) scrollViewDidScroll; called super but was not intercepted properly and skipped that call.
When I removed the "overridden" call, that was just a call to [super scrollView], it started working properly.
I don't know why apple's code is broken that way (calling super doesn't have the same effect not overriding it), but make sure you're not subclassing these:
ScrollView functions
MKMapView functions...
or perhaps using the WildCard Gesture Recognizer provided very kindly by the answer to why Map Views don't respond to touchesBegan/Moved etc here: How to intercept touches events on a MKMapView or UIWebView objects? .
If this doesn't help, ensure you don't have a view on top of the other views, improper delegates, xibs are arranged and hooked up, the usual stuff.

Monotouch - programming for Swipe Gesture

I am developing a control for an IPAD application (My first time doing Apple development). Its a simple control that mimics a grid - consists of a collection of UIViews (each of which represents a cell) all added to a parent UIView (in a grid like fashion).
One of the requirements is to implement a swipe gesture - the users swipe across the grid to activate/inactivate the cell - this corresponds to a 1/0 in the database.
I create a UISwipeGesture and added it to each of my UIView which represents a cell. That appears to be an incorrect approach as it fires the event for the UIView in which the swipe originated but not across all the UIViews.
My understanding would be that i need to implement the SwipeGesture across the parent UIView which contains all these children UIView. However if i do that how will i know which child UIView has been swiped over? Or any other approach which would make sense?
I know this thread is fairly old, but I created a Swipe extension method that might have helped.
View.Swipe(UISwipeGestureRecognizerDirection.Right).Event += Swipe_Event;
void Swipe_Event(ViewExtensions.SwipeClass sender, UISwipeGestureRecognizer recognizer)
{
View view = sender.View; // do something with view that was swiped.
}
This may not answer your question, but I can speak to the approach I've taken here with a similar use case:
1) I would abandon UIScrollView and use UITableView. You'll notice that UITableView inherits from UIScrollView and has all the performance benefits of virtualization and cell / view re-use. Which you'll find terribly useful as you work towards optimizing your app for performance on device.
2) Utilize the UITableViewCell's ContentView to create custom "Grid" cells. Or better yet, utilize MonoTouch.Dialog if you're not required to create Grid rows ad-hoc.
3) Use this awesome class (props to #praeclarum) to setup gestures in MonoTouch. You essentially provide a UIGestureRecognizer as a generic argument. You can then utilize the LocationInView method to grab the point in the UITableView where the gesture occurred
public void HandleSwipe(UISwipeGestureRecognizer recognizer)
{
if(recognizer.State == UIGestureRecognizerState.Ended) {
var point = recognizer.LocationInView(myTableView);
var indexPath = myTableView.IndexPathForRowAtPoint(point);
// do associated calculations here
}
}
I think you're correct that the gesture recognizer has to be attached to the parent view. In the action method associated with the gesture recognizer I think you can use the Monotouch equivalent of CGRectContainsPoint() to determine whether the swipe occurred in a particular subview. I imagine you would have to iterate through the subviews until you found the one in which the swipe occurred. I'm not aware of a method that would immediately identify the swiped subview.

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