Determine state of viewcontroller in storyboard - ios6

I'd like to know how to manage this:
I have 4 viewcontrollers in a storyboard, each one has the same class but i would like to know how to determine when they change their state from fullscreen to invisible and viceversa. any hints?. BTW i have a main view that works like evernote with multiple tabs, and i can already switch between them but i want to put different return buttons on each view, don't know where to begin.

You can find out the size of the window with self.view.window.bounds and test it against the frame of your ViewControllers' view with:
CGRectContainsRect(self.view.window.frame, myViewController.view.frame)
This will return true if the view is on screen and false otherwise.

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cannot find GoToElementState under VisualStateManager & VisualStateManager.GoToState returns false

I am trying to use animation using (For a windows 8 Phone Application)
VisualStateManager
But when i do
VisualStateManager.GoToState
it returns false. I have defined all the states and grids properly. I have a Grid Layout with name "ContentPanel" under the Main Grid Layout. Under "ContentPanel" i have rectangles on which this animation has to work. I have created all those rectangles dynamically using Code Behind. I have created all the states and animations in the same code and trying to run this above mentioned line.
I have googled and found different solutions to use GoToElementState() method. But i do not see this method in the class VisualStateManager class that i use. I know that is a static method, But it doesnt show up in the suggestions.
I Also tried to use ExtendedVisualStateManager class. Even this is not available.
Above all, I am not sure why my GoToState is not working. If i have the main element as a Grid (as LayoutRoot) then this animation is working. I used following lines
VisualStateManager.GetVisualStateGroups(this.ContentPanel);
// ContentPanel is the name of the layout
where i have other rectangles on which the
animations has to be binded. Then i used this command..
VisualStateManager.GoToState(this, "stateName", true) // Returns false. Nothing happens when this is executed. Can any one please suggest me with the right implementation of this.
Thanks,
Sri Tej N.
If your Visual States are under a Grid, then
VisualStateManager.GoToState(this, "stateName", true)
won't work because this is most likely a Page, which doesn't contain the Visual States directly.
and
VisualStateManager.GoToState(this.YourGrid, "stateName", true)
won't work either because GoToState's first parameter needs to be a type of Control - Grid doesn't inherit from Control.
You will need to use this one.
ExtendedVisualStateManager.GoToElementState(this.YourGrid, "stateName", true)

WPF Printing multiple pages from a single View Model

I am currently a little bit troubled by the following problem. I have a user interface which basically shows a graphic (a canvas made of Lines, Circles, ... these are all WPF objects). Depending on the selection a user makes in the menu, some items get deleted and some get added. So the basic image looks the same, but a few modifications are made.
The user has the possibility to select - say - 10 different "pages" by clicking a Next/Previous Button.
I am using MVVM Light and my ViewModel contains all the items of the graphic (all Lines, ...).
Now I would like to print that graphic to multiple pages. The first page should contain the graphic with changes from page 1, the second page contains the graphic with changes from page 2 and so on. The actual number of pages is dynamic. I track this with a property CurrentPage and a property PagesTotal.
Whenever I push the "Next" button, this causes a command to be executed which will change the variable CurrentPage and also makes sure that the correct items are displayed.
Now I would like to print this but this is where I'm stuck. I dont' mind leaving the MVVM zone and doing some dirty work in code-behind but I would refuse to draw everything again like in the old GDI days.
Any ideas are really welcome.
Create a UserControl containing your display logic (you graphic, for instance). Grab you ViewModel list and project then in UserControls, setting each ViewModel as each UserControl's DataContext.
Force each one to render calling Measure with infinite value and then Arrange with the resulting DesiredHeight and Width. Then follow the procedures to print WPF visuals (link link link).
Essentially, this should be quite simple if and only if your views work independently; i.e. your ViewModel doesn't contain UiElements that are placed into your View.
Simple solution is to basically print your visual root. If need be encapsulate your Views in a user control first.
PrintDialog printDlg = new PrintDialog();
UserControl1 uc = new UserControl1();
printDlg.PrintVisual(uc, "User Control Printing.");
Reference
Alright, I have to admin that I now switched back to doing the printing through code only. I would have really liked doing it "WPF-style" but handling the multiple pages issue was just too much trouble.
Anyway, there is still one issue regarding the printout left but this will be another question.

Animating a view created in IB using Autolayout

I have a view with a lot of labels and buttons which are created on code because in IB is too complicated. This works ok.
In IB I also created an input view which I want to appear from the bottom by the tap on a button. Very much like a keyboard if you will. Because this input view is strigth forward, it has been created on IB and it contains sliders, labels, etc. I haven't added it as a subview of self.view on IB.
By the tap of the button, I set up all the constrains for the input view: I set the width, I set it on the bottom of the self.view with vertical size, then I remove this constraint, I add the actual heigth and then I animate with [self.view layoutIfNeeded].
The thing is that the input view itsef animates correctly, but its subviews not so much. They kind of appear at once.
I have tried adding a input view programmatically, with only one switch. It animates quite nicely.
I'm guessing that there is a problem with the constrains between the controls and their superView. But I'm not sure about it, because although they do not animate correctly, they are on the correct place and witht the correct proportions. I guess I'm missing something here. Maybe it's not a good idea to mix IB set controls and views and programmatically modifying them?
Does somebody have any experience with that?
Thanks in advance,
I suggest you post to Apple's dev boards on this subject. I've seen several posts there recently. The Apple Engineers who replied said that with Autolayout, you basically give autolayout ownership of your view's center, size, and sometimes, transform.
To animate views that use autolayout, you should apparently use UIView block animation and animate the constraint settings on the views. The system will then animate the changes you make.
Not sure about adding new views programmatically and having them animate into place however.

WPF: Determine if a Panel is visible to the user

I have a WPF usercontrol (myGraphicControl) in a tab (WPF application).
When the form size changes, I redraw the graph in myGraphicControl.
Since the redrawing operation is a I need to do it only the control in in the visible tab.
How the WPF (user)control can detect if it's "visible" actually or not?
PS.
by Visible I mean that user can see it.
say, if a Visible TextBox is located in the currently invisible tab, this textBox is not visible by the user.
I don't believe there is a quick-fix solution here, but you may be able to do something using UIElement.InputHitTest(Point).
You could make a call similar to
//get the coordinates of the top left corner of the child control within
//the parent
var childTopLeft = childControl.TranslatePoint(new Point(), parentControl);
//check whether or not the child control is returned when you request the element
//at that coordinate through hit testing
var isVisible = (parentControl.InputHitTest(childTopLeft) == childControl);
However, I should point out that I haven't tried this myself, and that it probably won't work in the following scenarios:
Transparent items - generally, transparent backgrounds cause hit testing of a control to pass to the parent
Partially occluded items - you can only hit-test one point at a time, so if only part of your child control is visible you will have to check the correct point
I've found that while Steve's method generally works, it works much more reliably if you get a point from somewhere in the middle of the child control. I'm guessing that maybe layout rounding somewhere along the way makes the InputHitTest check somewhat inexact. So, change his first line to the following and you're golden:
var childTopLeft = childControl.TranslatePoint(new Point(childControl.RenderSize.Width/2, childControl.RenderSize.Height/2), parentControl);
Maybe UIElement.IsVisible will be helpful? It works for tab contents well.
Anyway you can use a solution described here.
I have one more solution. The current implementation of TabControl removes inactive tabs from visual tree. So, another way to determine whether your element is visible is to find PresentationSource. It will be null for elements of inactive tabs.

Rotating windows in WPF

I need to create a WPF application which is maximized and which rotates amongst about 10 different screens. Each screen will take the entire area and show different content.
I already know how to maximize the window with
My question is what is best to put inside that window to achieve what I want?
Ideally I'd be able to have 10 different .xaml files and I just load one after the other to take the entire screen. I'm not sure the best approach for accomplishing this in WPF.
Thank you!
One quick way to do this is to use WPF's built in page navigation. By making your root window a NavigationWindow and each view a class derived from Page (similar to work with to a UserControl or Window) you can just set the NavigationWindow.Source to a relative URI that points to the page you want to show (like a web browser) and simply switch it as needed.
This sounds like a classic MVVM application, which is simply too much to put into detail here. Google MVVM or Model-View-ViewModel, or pick up the book Advanced MVVM by Josh Smith (widely regarded as an expert in such things).
However, this is basically what you are going to have:
One class, the ViewModel, is an abstraction of the data that you need to bind to
Your data Model
A View for each thing you want to show. A View is simply something that holds your UI, be it a DataTemplate or a UserControl. Each View is bound to the ViewModel
The Views are the things that will "rotate" (although rotate in WPF implies animation and/or transformation). How you switch between them is up to you, although it sounds almost like something that would be done with a DispatcherTimer and animation (i.e. like fading between pictures in a slideshow).
This question is really too broad for this forum - you will need to do quite a bit of research on WPF fundamentals before proceeding. Again, MVVM is a good direction to start.
EDIT: Something More Lowbrow, per OP Request
This is probably as simple was you can make it (and still create separate XAML files for each piece of content):
First, create 10 UserControls (XAML files) for the stuff you want to show.
Next, add an instance of each of these user controls to your main window. Set the Visibility of each of these to Collapsed, except the first one to show.
Put a "Next" button on the main window.
In the code-behind, handle the Click event for the Next button. In there, keep track of which UserControl is visible, by name. Set the one that is currently visible to Visibility.Collapsed, and set the next one that is supposed to be visible to Visibility.Visible.
This is certainly an ugly solution, and not very WPF-ish, but it will get the job done.

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