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.
Related
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");
}
}
}
}
I have a UISplitViewController which has a UINavigationController in the master and a UIViewController in the detail. When the device is orientated into landscape mode I want the normal behaviour to be preserved. I.e. The master gets shown in landscape and hidden in portrait.
However depending what the user clicks in the master depends on which UIViewController is loaded into the detail part of the UISplitViewController. What I would like is for the master to be hidden in landscape mode when a user clicks on a button in the detail UIViewController. The problem is I can't get this to work.
My delegate looks like this (have removed some lines for simpler viewing):
public class SplitControllerDelegate : UISplitViewControllerDelegate {
SplitViewController incomingController;
private bool hideMaster = false;
public override bool ShouldHideViewController (UISplitViewController svc,
UIViewController viewController,
UIInterfaceOrientation inOrientation) {
return hideMaster;
}
public void SetHideMaster(bool value) {
hideMaster = value;
}
}
I then call it from the detail UIViewController like
splitControllerDelegate.SetHideMaster(value);
However nothing changes. I'm unsure of how to make it perform the change? Should the master disappear immediately? What causes the WillHideViewController to fire?
Thanks
Mike
What you're trying to do cannot be done officially. ShouldHideViewController() is called only upon device rotation. So unless you rotate forth and back, your controller won't disappear.
You have various options:
Don't use UIListViewController but some other third party replacement
Use UIViewController containment feature of iOS5 and implement your own split view
Apply a hack to UISplitViewController
About the last point. You should be able to force ShouldHideViewController() being called if you set the Delegate property to NULL and then assign a new delegate. Afterwards, call the WillRotate() method of the split view controller using the current orientation.
I'd go for the 2nd option.
By design you cannot do much with the standard UISplitView, try that third party control :
https://github.com/mattgemmell/MGSplitViewController
I'm creating an IPad application using C#, Mono develop and Monotouch.
I've been using Monotouch.Dialog to create functionality similar to the wifi-settings on an iPhone. I'm using StyledStringElement with an accessory and am now trying to differentiate between tapping the row and tapping the DetailDisclosureButton.
I've been found out that I should override the UITableViewDelegate.AccessoryButtonTapped on the UITableView. I've tried to created a derived class from UITableViewDelegate and hook this into the Monotouch.Dialog. But this is where I got stuck. I didn't manage to replace the existing UITableViewDelegate with my extended version.
So my questions are:
Is this the preferred way of handling this event (to be able to differentiate between a tap on the element and a tap on the DetailDisclosureButton) ?
If not, any pointer on how to accomplish this ?
I have been searching the web for a (similar) example but have not found any yet. Any examples that you know of that could get me started ?
Thanks,
boris
event EventHandler accessoryPushed;
public override void AccessoryButtonTapped (UITableView tableView, NSIndexPath indexPath)
{
if(!accessoryPushed)
{
accessoryPushed(this,EventArgs.Empty);
}
}
You will need to add this to the DailogViewController code that you are using (this will override the tapping action). Instead of a simple function, you may want an event to be triggered, so just handle the event in your main code. That is probably your best bet.
Once you change this line, you will have to implement new functions like AccessorySelected (just mimic the path the code follows when a row is selected except with accessory).
On the other hand, you could try a different navigation method, often disclosure buttons are annoying and you don't want to click on them except to get simple information about the button (like a help feature).
I haven't found any other examples, sorry!
my question is about view controllers, delegates and all that in general. I feel perfectly comfortable with UIView, UIViewController, Delegates and Sources, like UITableView does for instance. It all makes sense.
Now I have implemented my first real custom view. No XIBs involved. It is an autocomplete address picker very much like in the Mail application. It creates those blue buttons whenever a recipient is added and has all the keyboard support like the original.
It subclasses UIView. There is no controller, no delegate, no source. I wonder if I should have either one of those? Or all, to make it a clean implementation.
I just cannot put my finger on the sense a view controller would make in my case. My custom view acts much like a control and a UIButton doesn't have a controller either.
What would it control in my view's case?
Some of my thoughts:
For the source: currently the view has a property "PossibleAutocompleteRecipients" which contains the addresses it autocompletes. I guess this would be a candidate for a "source" implementation. But is that really worth it? I would rather pass the controller to the view and put the property into the controller.
The selected recipients can be retrieved using a "SelectedRecipients" property. But views should not store values, I learned. Where would that go? Into the controller?
What about all the properties like "AllowSelectionFromAddressBook"? Again, if I compare with UIButton, these properties are similar to the button's "Secure" property. So they are allowed to be in the view.
The delegate could have methods like "WillAddRecipient", "WillRemoveRecipient" and so on and the user could return TRUE/FALSE to prevent the action from happening. Correct?
Should I maybe inherit from UIControl in the first place and not from UIView?
And last but not least: my custom view rotates perfectly if the device is rotated. Why don't all views? Why do some need a controller which implements ShouldAutoRotateToDeviceOrientation()?
Does it make sense what I wrote above? In the end I will provide the source on my website because it took me some time to implement it and I would like to share it as I have not found a similar implementaion of the Mail-App-like autocomplete control in MonoTouch.
I just want to learn and understand as much as possible and include it in the source.
René
I can answer part of your question.
I just cannot put my finger on the
sense a view controller would make in
my case
The ViewController is responsible for handling the View's state transitions (load, appear, rotate, etc) These transitions are used mainly when you use a navigation component (UINavigationViewController, UITabBarController). These components needs to received a ViewController that will handles the view's transitions.
For exemple, when you push a ViewController on a UINavigationViewController, it will cause the ViewDidLoad, ViewWillAppear, ViewDidAppear. It will also cause the ViewWillDisappear, ViewDidDisappear of the current ViewController.
So, if your application has only one portrait view, you don't need a ViewController. You can add your custom view as a subview of the main window.
Does any one have an idea how to access the UIScroller class , which is the default subview of UIWebView ?
I want to handle the touches, zooming , panning and scrolling features inside the webview .
Thanks..
I know this thread is old but if anyone comes across it there's a new way.
As of iOS 5 UIWebView now has a property called scrollView which you can't replace but you can set the properties of it. Most people just want to disable zooming/bouncing/scrolling all together which can be done by setting the properties of the scrollView for example if webview is a UIWebView:
webview.scrollView.bounces = NO; //Disables webview from bouncing
webview.scrollView.minimumZoomScale = webview.scrollView.maximumZoomScale = 1.0; //Forces zoom to be at 1 (can be whatever you fancy) and disables zooming
webview.scrollView.bouncesZoom = NO; //Disables bouncing when zooming exceeds minimum or maximum zoom
I suppose you could set the delegate for the scrollView if you want more control, though to be on the safe side you might want to store the original delegate and call its methods appropriately in your custom delegate.
Handling the touches would be more difficult since you can't replace the scrollView to provide your own handlers. Best you could do is add some gesture recognizers as part of the UIView and try to handle them there, but I think UIWebView will still receive the events. Alternatively in iOS 5 they let you access the gesture recognizers directly on UIScrollView.
You can find this by going like this:
[webview objectAtIndex:0]
That should be where it is. If not, put this in your code somewhere and run the program to search for the index of the UIScroller, and replace the 0 above with that index:-
for (UIView *subview in [webView subviews]){
NSLog(#"subviews of webView : %#", [[subview class] description]);
}