Getting width of Monotouch.Dialog UIViewElement? - xamarin.ios

I'm trying to make an UIView (for a UIViewElement), but how do I get the bounds (at least width) of this UIViewElement?
Thanks
Mojo

UIViewElement just takes the view that you pass into the constructor and adds it to the ContentView of the UITableViewCell.
Since cells are dynamic and not all of them are the same size...
I would recommend you create a UIViewElement subclass with a ContentViewBounds property and set that value inside the GetCell method for your custom element.

Related

UILabel not wrapping in UITableView until device rotate (iOS8)

I have a custom MvxTableViewCell that is associated with an MvxStandardTableViewSource. That Source is then applied to a UITableView. The custom table cell is defined without any Storyboard or NIB. It is laid out in code and uses AutoLayout.
this.searchResultsTable = new UITableView();
this.searchResultsTable.AccessibilityIdentifier = "SearchView_SearchResultsTable";
this.searchResultsTable.TranslatesAutoresizingMaskIntoConstraints = false;
this.searchResultsTable.RowHeight = UITableView.AutomaticDimension;
this.searchResultsTable.EstimatedRowHeight = 44.0f;
this.searchResultsTable.RegisterClassForCellReuse(typeof(CustomerItemCell), new NSString("CustomerItemCell"));
this.searchResultsTable.AllowsMultipleSelectionDuringEditing = true;
this.searchResultsTable.TableFooterView = new UIView();
this.searchResultsTableDataSource = new MvxStandardTableViewSource(this.searchResultsTable, new NSString("CustomerItemCell"));
this.searchResultsTable.Source = this.searchResultsTableDataSource;
The MVxStandardTableViewSource is databound to a ViewModel property of type List
var set = this.CreateBindingSet<SearchView, SearchViewModel>();
set.Bind(this.searchResultsTableDataSource).To(vm => vm.SearchResults);
set.Bind(this.searchBar).For(x => x.Text).To(vm => vm.CurrentSearchCriteria);
set.Apply();
This all works fine until an item in the data source causes some text wrapping in one of the UILabels and consequently a different height to the other cells.
The cell height is mostly correctly calculated but the UILabel within the
cell does not get redrawn until the device is rotated. I am using iOS AutoLayout to layout the various UIViews in the Cell.
Here are some examples of the large cell in my layout, see the
person "THISISAPATIENTWITHA-" (note this is test data not real people's data)
Initial display of cells
Same cells but device has been rotated
Still the same cells with device rotated back to original
How do I get the UILabel to redraw? We only need to support iOS8 and above.
I cannot see an event or method that gets called when the data binding has happened that would allow me to effectively tell the custom cell "You now have your subviews populated with bound data so redraw them"
The table has another issue too that is covered by this question, Implementing cell reuse for varying height cells in UITableView
Simple Repro on Github
https://github.com/munkii/TableCellResizeIssue
UPDATE:
I've forked your GitHub project and submitted a pull request. But here's my updates to your project.
https://github.com/SharpMobileCode/TableCellResizeIssue
First, you're using FluentLayout for your constraints. Nothing wrong with that actually, but that's some good info to tell others. :)
Second, in order for UITableView.AutomaticDimension to work on TableView Cells, there must be enough autolayout constraints defined in order for the cell to calculate the height of the cell. UITableView.AutomaticDimension depends on proper AutoLayout constraints.
Since you were using FluentLayout to abstract iOS AutoLayout constraints, this was not obvious as no warnings were present in the application output window. Though FluentLayout was technically correct, it however wasn't enough for UITableView.AutomaticDimension to automatically calculate each cell height.
So what I did was added a few more constraints. Look in CustomerItemCell.CreateView() in the pull request (or my github link). You can see that I added additional constraints for all the bottom labels so that they add a Bottom Constraint to the ContentView (Just like you did with this.bornLabel). This had to be applied to all the labels on the bottom of the cell. This gives AutoLayout enough information to properly calculate the cell height.
Third, This almost works, but if you rotate to Landscape, you'll notice that the long name cells will be bigger and have extra padding. To fix this, I created another class called AutoLayoutLabel that inherits from UILabel. I overrode the Bounds property so that it changes the PreferredMaxLayoutWidth to the proper width when rotated to Landscape, and back to Portrait. You then will need to use AutoLayoutLabel instead of UILabel. You'll need this for all labels that need to wrap. I'm not sure how to set PreferredMaxLayoutWidth to auto in code, but this is how to do it programmatically (which also works for iOS 7).
public class AutoLayoutLabel : UILabel
{
public override CGRect Bounds
{
get
{
return base.Bounds;
}
set
{
base.Bounds = value;
if(this.Lines == 0 && Bounds.Size.Width != PreferredMaxLayoutWidth)
{
PreferredMaxLayoutWidth = Bounds.Size.Width;
SetNeedsUpdateConstraints();
}
}
}
}
Well, that should do it!
I now have a solution to this part of my issue. Prompted by #SharpMobileCode reference to PreferredMaxLayoutWidth I decided to give that another go. Rather that setting it to Automatic (which seems impossible in code) I am setting it Explicitly, once AutoLayout has done its thing. Like this
/// <summary>
/// Lays out subviews.
/// </summary>
public override void LayoutSubviews()
{
base.LayoutSubviews();
this.nameLabel.PreferredMaxLayoutWidth = this.nameLabel.Frame.Size.Width;
}
I am no longer seeing the Labels not wrap (hurrah!) however I am seeing an issue with what looks like cell reuse. Once I scroll all of the cell off the top of the screen I can scroll it back on and it has reverted to the same height as all the other cells. I can see the label is still wrapping but the cell height is wrong.
The standard table views in MvvmCross date back to iOS4 - while the new UITableViewAutomaticDimension sizing wasn't really added until much more recently (iOS8?)
Most real apps tend to use custom cells rather than the standard ones, but if you do want to use the standard ones, then I'd guess you could try adding some code to the setters in the cell which would trigger resize recalculations - e.g. to setters in https://github.com/MvvmCross/MvvmCross/blob/3.5/Cirrious/Cirrious.MvvmCross.Binding.Touch/Views/MvxStandardTableViewCell.cs#L73
I would guess that judiciously placed calls in there to request layout recalc would cause the parent cell and table to redraw.

how to know the height of a control? I get NaN

I have an application that use the MVVM pattern. In the main view model, I create a view and its viewmodel of another control.
I need to know the height of the control, but when I create the control, if I see the Height value of the control I get NaN.
I use this code in my main view model:
miSecondControl = new mySecondControl(param1, param2);
double myHeight = miSecondControl.height;
This secondary control does not use the MVVM patter but it has code behind, because I only want to use it to print a fixed document, so I think that in this case MVVM would make more complex the solution.
I need the heigh property of the control to know if I need to create a new page because I don't have space in the actual page.
Thanks.
Height/Width are values that are specified at design/layout time.
Use FrameworkElement.ActualHeight and FrameworkElement.ActualWidth to get the rendered Height/Width of a control.

JavaFX access controller's variables from Scene Builder

If I declare something like
#FXML
private final static double PREF_SPACING = 10d;
or
#FXML
private Insets insets = new Insets(10d);
in the controller class,
is there a way to use their values in Scene Builder?
When I want to change the value, I want to change
it only once, in the controller class.
PRELIMINARY ANSWER
I haven't yet tried all of the techniques below, but it seems to be the way you would do it from reading the documentation. If I get some time, I'll try it out later and update this answer with results (or somebody else can do this and post a new answer or edit this one to create a definitive answer). I just wanted to publish something now to point you in what I believe to be the right direction.
If the below is not what you are looking for, add a few more specifics to your questions to fully describe what you want.
Don't using the #FXML annotation here. #FXML is for injecting values from the markup into the controller, not the other way around.
For your first example which is a constant, let's say your controller class is:
class MyControllerType {
public final static double PREF_SPACING = 10d;
}
Then in your fxml, reference the constant:
<?import MyControllerType?>
...
<VBox>
<spacing><MyControllerType fx:constant="PREF_SPACING"/></spacing>
</VBox>
For your second sample which is not a constant or a part of the SceneGraph, you can use an fx:define element to instantiate an instance of the class. Note that you can't directly instantiate an Insets class from FXML as it has no builder class nor zero length constructor. So what you might be able to do is create another placeholder class for the information and instantiate a reference to that in your FXML (or you can create a Builder that FXML can use to instantiate the Insets).
class InsetsHolder {
private Insets insets = new Insets(10d);
public Insets getInsets();
}
<?import InsetsHolder?>
<fx:define>
<InsetsHolder fx:id="i"/>
</fx:define>
<VBox>
<Button text="Click Me!" VBox.margin="$i.insets"/>
</VBox>
SceneBuilder should be able to read fxml files which use the fx:define and fx:constant notation, as well as (possibly) make use of the reference expression $i.insets. SceneBuilder might not have any UI to allow you to edit the values from within the SceneBuilder application, so you will probably need to hand edit the fxml file portions related to the fx:define and fx:constant elements if you wish to make use of these structures.
There is an executable example of using an fx:define element in this mailing list post on designing resolution independent units in FXML.
In general, I think I'd be a bit cautious of maintaining these kind of dependencies between fxml and java code. It may be more prudent to do more of this kind of stuff in plain Java code within the context of the controller initialize method as scottb suggests.
The #FXML annotation enables the JavaFX objects whose names you defined (fx:id) to have their references reflectively injected into nonpublic fields in the controller object as the scene graph is loaded from the fxml markup.
To the best of my knowledge, this is a one way operation. There is no provision for having named static class variables in the controller object injected into the scene graph during loading.
You can accomplish something very similar to what you are requesting by defining the values that you want set as class variables in your controller object's class, and then setting the appropriate object properties programmatically (rather than in markup) in the initialize() method of your controller object.
The initialize() method is called (if it is present) after the loading of the scene graph is complete (so all the GUI objects will have been instantiated) but before control has returned to your application's invoking code.

MonoTouch.Dialog: Setting Entry Alignment for EntryElement

Using the EntryElement to enter data as is results in the data being entered being aligned sort of in the middle.
How do I specify that the entry should be right aligned on an iPad.
For example:
Have you tried overriding CreateTextField on EntryElement ?
That should give you complete control on how to create the UITextField being used for the entry part of the element.
Update Notice that if you override CreateTextField, you should also override the Cellkey property, to ensure that this cell is not shared through the UITableView cell-sharing machinery with other EntryElements.
Of course you'll need to know the right size before being called (or delay settings some properties until you know for sure).

subclass uitableview already in a UIView

I am trying to implement Leah's "Pull to Refresh" code (https://github.com/leah/PullToRefresh) in to my UITableView. However, I have a UIView, so cannot subclass the tableViewController as is required by this.
My structure is
UIView
- UITableView
So there's a UITableView inside my main UIView. I use a UIViewController obviously - and this cannot really change (I think!)
I have tried to change the class in interface builder to the custom uitableviewcontroller above (the pull to refresh one) but it doesn't let me.
Any ideas on how I can subclass the UITableView - NOT the tableViewController??
Here is how I did it:
Change PullToRefreshTableViewController so that it subclasses UIViewController, NOT UITableViewController. Next, add a UITableView * property called tableView to PullToRefreshTableViewController and synthesize it. Lastly, modify your view controller so that it subclasses PullToRefreshTableViewController instead of UIViewController.
That should give you a working implementation of it.

Resources