For Xamarin.Forms.DatePicker It is not obvious that the date field is "tapable" I want to change the text color of it to blue so the user will think it is clickable?
I see a background color property but not forecolor/text color?
Let me know how I can do that.
I did it just creating a class like that on my Android Project and making no changes on my Forms Pages:
using Xamarin.Forms;
using xxxx.Droid;
[assembly: ExportRenderer(typeof(Xamarin.Forms.DatePicker), typeof(MyDatePickerRederer))]
namespace xxxx.Droid
{
public class MyDatePickerRederer : Xamarin.Forms.Platform.Android.DatePickerRenderer
{
protected override void OnElementChanged(Xamarin.Forms.Platform.Android.ElementChangedEventArgs<Xamarin.Forms.DatePicker> e)
{
base.OnElementChanged(e);
this.Control.SetTextColor(Android.Graphics.Color.Black);
}
}
}
I don't think that the forecolor/text color is accessible at this time and I'm not sure if it will be in the future or not. Typically what you would do in this scenario is create a Custom Renderer to get down into the native implementation of the UIDatePicker control for iOS and change it's properties there. The problem with that in this case is that if you look through the iOS SDK documentation as well, I don't believe there is a way to customize the text on the UIDatePicker picker control. This is why you can't do it in Xamarin.Forms either.
At this point you will probably have to create your own custom control/renderer to make such a small change. Frustrating, I know, but unfortunately that this point I don't think you can actually accomplish the simple thing you are looking to do. :-(
Related
I'm building an Android and iOS app using Xamarin Forms.
What I'm simply trying to do is set a background drawable on my Android app for my ListView items. The root view of my ListView items are StackLayout's:
var listView = new ListView
{
ItemsSource = items,
ItemTemplate = new DataTemplate(() =>
{
return new ViewCell
{
View = new StackLayout(...)
};
}
};
I know I can access the native element by using a custom renderer:
public class MyEntryRenderer : EntryRenderer
{
protected override void OnElementChanged(ElementChangedEventArgs<Entry> e)
{
base.OnElementChanged(e);
if (e.OldElement == null) {
var nativeEditText = (EditText)Control;
...
}
}
}
But I'm not sure how this would work for a StackLayout (or any other layout for that matter).
I first extended StackLayout:
public class ListViewItem : StackLayout
{
}
And I read somewhere that layouts use the VisualElementRenderer, so I tried the following:
public class ListViewItemRenderer : VisualElementRenderer<StackLayout>
{
protected override void OnElementChanged(ElementChangedEventArgs<StackLayout> e)
{
base.OnElementChanged(e);
// any way to access the native element?
}
}
But VisualElementRenderer does not seem to give me access to the native element.
So is there any way I can access the native elements of Layout elements? Or maybe there is a different way to simply set a background drawable on layouts within my Android app?
Even though I still don't know how to access the native element of a layout, the VisualElementRenderer has a method for setting the background drawable on Android (which was exactly what I needed). So I ended up with the following:
protected override void OnElementChanged(ElementChangedEventArgs<StackLayout> e)
{
base.OnElementChanged(e);
SetBackgroundDrawable(Resources.GetDrawable(Resource.Drawable.listViewItem));
}
I understand you want to hook into an existing Layout renderer and extending it to access the native element with extra capabilities like background image.
Eventually the support for background-image will be supported just like background-colour is, I imagine, across the Layout controls. It may be worth while waiting for this as I can't see why they wouldn't implement these in a later release.
In the mean time you would need something that would work and is quite easy to implement?
Creating the background drawable via inheriting the renderer from a Layout may not be the simplest of solutions therefore, although does have its advantages as you can then re-use easily with the extra functionality across all Layouts for an application.
In your code for ListViewItemRenderer, however, it is inheriting from a Xamarin.Forms control (you specified StackLayout) and have not specified a native, platform dependent, control to be the base for the layout control that would have to match the Xamarin.Forms platform dependent control used.
Each Renderer is tied to a native element. Layout controls will be no different than other custom native control renderers.
For a custom control, you will write a renderer something like the following (note I haven't specified a layout renderer as I haven't had a need to do this yet and am just going from past experience - but similar rules should apply to implementing a renderer for a layout as opposed to a custom control):-
// System.Windows.Controls.Grid in this case is the root native control for a WindowsPhone renderer of MyControl
public class MyControlRenderer : ViewRenderer<MyControlView, System.Windows.Controls.Grid>
There is a simpler approach, however to achieve what you want to do:-
The simpler approach would be instead of inheriting from the Stack Layout control, it would be better to inherit from Grid as the root of the control.
Then you can add an Image control to the Grid and also a Stack Layout for the same Grid Row and Column.
By doing the above you will be able to achieve a background-image across the entire listview item row.
I'm trying to put a joypad made with AndEngine on a WebView that will be the view of an ipCamera. How can I do? I've searched a lot about that, but still haven't found the solution. Thank you all very much
You didn't mention what version of AndEngine you are using.
If you are using GLES2 (same technique may work for the GLES1 branch but I have not verified that), look at the AndEngine TextBreakExample.
That example shows how to use the org.andengine.opengl.view.RenderSurfaceView in combination with another layout like a LinearLayout. The "other layout" can contain anything - this example uses an EditText, but you should be able to use a WebView using the same technique.
Be sure and check the res/layout/textbreakexample.xml file. Also note these extra methods in the TextBreakExample.java file
#Override
protected int getLayoutID() {
return R.layout.textbreakexample;
}
#Override
protected int getRenderSurfaceViewID() {
return R.id.textbreakexample_rendersurfaceview;
}
https://github.com/nicolasgramlich/AndEngineExamples/blob/GLES2/src/org/andengine/examples/TextBreakExample.java
https://github.com/nicolasgramlich/AndEngineExamples/blob/GLES2/res/layout/textbreakexample.xml
Also might check out this layout file
https://github.com/nicolasgramlich/AndEngineExamples/blob/GLES2/res/layout/xmllayoutexample.xml
I am trying to do this:
public class DialogMenuHawaii extends Dialog {
Style s = UiFactory.getBaseStyle();
s.setBgTransparency(0);
s.setBgImage( <my image >);
this.setUnselectedStyle(s);
}
but it doesn't work.
First, I suggest you use a theme. We constantly change small implementation details e.g. customizations like the one you are doing will not be portable between LWUIT 1.4 and 1.5. There is no reason whatsoever not to use a theme for something like this.
If you are interested in the pain and suffering of manually coding view logic into your application you can use several methods such as getDialogComponent() to get the style from them and manipulate that. Dialog is a complex beast due to the fact that its really a form padded away from the edges.
Open your '.res' file in resource Editor and select your preferred theme,
Under 'Unselected' tab open the DialogContentPane style, if you don't have one create it look at the end of this answer on HOW TO DO IT?, and set the background image to the image you need to show as Dialog bg
Under 'Unselected' tab open the DialogBody style, if you don't have one create it look at the end of this answer on HOW TO DO IT?, and set the background transparency as '0' and also make sure the background image type is NONE
NOTE: The above code will reflect for all the Dialogs in your application. If you want a particular dialog with background image than derive new styles from these default styles, and follow the above steps to apply it to your DialogMenuHawaii or any runtime Dialogs.
HOW TO: I would recommend you to go through the Shai's blog posts LWUIT Resource Editor Tutorial Part 1 till part 10. To better understand the Resouce Editor its features and capabilities.
:
:
:
PS: Programmatic-ally i haven't been able to achieve it using TextArea which is the case for default Dialog's. If you replace the dialog body component with Label if works fine, the code sample is given below. I haven't delved much into why is it so ? maybe will do it in my free time. Hence i have proposed a working alternative solution which is scripted above using Resource Editor and below using the code
class MyDialog extends Dialog {
public void show() {
Container octnPane = this.getDialogComponent();
octnPane.getUnselectedStyle().setBgTransparency(0, false);
Container ctnPane = (Container)((BorderLayout)octnPane.getLayout()).getCenter();
ctnPane.getUnselectedStyle().setBackgroundType(Style.BACKGROUND_IMAGE_SCALED, false);
ctnPane.getUnselectedStyle().setBgImage(myImage, false);
Label t = new Label("Dialog");
t.setUIID("DialogBody");
t.getUnselectedStyle().setBgTransparency(0, false);
ctnPane.addComponent(t);
super.show();
}
}
This is for Dialog background.
Dialog dialog = new Dialog();
dialog.getDialogStyle().setBgImage(Image.createImage("/image/image.png"));
If you want to set transparency of Dialog with image.
dialog.getStyle().setBgImage(Image.createImage("/image/image.png");
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!
Is it possible to customise the title bar in Java ME?
You might like to check out J2ME Polish, which provides a massive amount of UI customisation for MIDlets, including the title bar: link text
The API doesn't provide functionality for customising the default title bar, but we can attempt to write our own bar. This is in itself a minor breach of UI conventions. Some phones allow us to use setTitle(null) to remove the title. The phones in the Java mobile toolkit behave this way, but the Series 40 and 60 emulators don't seem to support this and instead generates a default title. On the other hand, the Sony Ericssons and Motorolas I've tested seem to support this.
However, we can detect whether the ability to remove the titlebar is present. We do not use the sizeChanged callback as the calling of this function may be delayed when the canvas is not visible. Instead we call getHeight both before and after removing the bar. According to the spec, getHeight should always return the correct and up to date value, even when the canvas is not being displayed. Here is code for implementing the detection:
public static boolean HIDE_TITLE_ENABLED;//Whether the implementation allows us to hide the title bar
static{
//See if we can remove the title by ensuring it is non-nil, then attempting
//to remove it. If we can't, then reset it.
Canvas c=new Canvas(){
protected void paint(Graphics g){
}
};
c.setTitle("test");
int preHeight=c.getHeight();
c.setTitle(null);
int afterHeight=c.getHeight();
HIDE_TITLE_ENABLED=preHeight!=afterHeight;
}
It is also possible to hide the title bar using full screen mode, but this hides other elements as well. This method is popular in games.