Convert ConstraintLayout to image - android-studio

I try to capture an image of all the elements inside my constaintLayout and then save it to the device.
I have done it on my iOS app, by capturing a UIView to an image with this simple line:
let theImage = self.myView.asImage()
Can I do something similar in Android Studio using Kotlin? Or is there any other layout/view better than constaintLayout that works like uiView in iOS?

Shameless copy and automatic to-kotlin conversion (litterally pasting the java code into a kotlin file in Android Studio) of https://stackoverflow.com/a/34272518/4265739
private fun createBitmapFromView(context: Context, view: View): Bitmap {
val displayMetrics = DisplayMetrics()
(context as Activity).getWindowManager().getDefaultDisplay().getMetrics(displayMetrics)
view.setLayoutParams(LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT))
view.measure(displayMetrics.widthPixels, displayMetrics.heightPixels)
view.layout(0, 0, displayMetrics.widthPixels, displayMetrics.heightPixels)
view.buildDrawingCache()
val bitmap = Bitmap.createBitmap(view.getMeasuredWidth(), view.getMeasuredHeight(), Bitmap.Config.ARGB_8888)
val canvas = Canvas(bitmap)
view.draw(canvas)
return bitmap
}
You can use the function above to create a bitmap containing the contents of the ConstraintLayout. In fact it should work for any View.
ConstraintLayout is the recommended layout to use in android. I cant tell if it works like iuView in IOS, but it is the Android way to do things.

Related

vaadin 7: layout displaced after opening/closing dialog window

I am new to the forum and to programming so hopefully I give you enough details and precise information needed to understand my question.
I am working with vaadin 7 in java EE web aplication and I have a layout problem/phanomena that I cannot explain and I could not find a solution on the net. Basically, when I start the server and test my application on localhost everything looks right. When I open a dialogue window and close it again, the layout of the site looks displaced. I could not find a pattern as to which click causes this effect. Sometimes it happens also when I only change a view. This is how it should look like and this is how it does look like after working in the application.
I looked through the devloper tool in the browser and noticed that in the working html, the attributes "top" and "left" are set for the gridlayout-slot. In the displaced layout these attributes are not set. Furthermore, it seems that the problem occurs more often in chrome. It does also happen in firefox but less often.
I use VerticalLayout, GridLayout and FormLayout.
Did you have similar experience? I am wondering how and when the html files are generated from the vaadin code to find out why they change and how I can fix it.
I am not sure which code exactly is causing the problem, so I am not sure what to post. If you have an idea where to look, I can add more code. Here is how the Dialog is set up:
public class Dialog extends Window implements ClickListener
public Dialog(CustomController controller, String title)
{
super(title);
setModal(true);
setStyleName("dialogWindow");
this.controller = controller;
setWidth("65.0%");
setHeight("90.0%");
// top level component properties
panLayout = new GridLayout();
panLayout.setWidth("100%");
panLayout.setHeight("100%");
buildPanToolbar();
panLayout.addComponent(panToolbar);
buildPanTop();
panLayout.addComponent(panTop);
buildPanTabs();
panLayout.addComponent(tabsheet);
panLayout.setComponentAlignment(tabsheet, Alignment.MIDDLE_CENTER);
panLayout.setRowExpandRatio(2, 1.0f);
tfThema.focus();
setContent(panLayout);
}
The buildSomething() functions are all a combination of GridLayout, FormLayout, HorizontalLayout and VerticalLayout. Below is the buildPanToolbar() function as an example
private void buildPanToolbar()
{
panToolbar = new HorizontalLayout();
panToolbar.setImmediate(false);
panToolbar.setWidth("100%");
panToolbar.setHeight("25px");
panToolbar.setMargin(false);
panToolbar.setSpacing(true);
panToolbar.setStyleName("toolbar");
HorizontalLayout panHelpToolbar = new HorizontalLayout();
panHelpToolbar.setImmediate(false);
panHelpToolbar.setWidth("-1px");
panHelpToolbar.setHeight("25px");
panHelpToolbar.setMargin(false);
panHelpToolbar.setSpacing(true);
panHelpToolbar.setStyleName("toolbarButtons");
panToolbar.addComponent(panHelpToolbar);
pbButton1 = new Button();
pbButton1.setCaption("Button1Text");
pbButton1.setStyleName(BaseTheme.BUTTON_LINK);
pbButton1.setImmediate(true);
pbButton1.setWidth("100px");
pbButton1.setHeight("-1px");
pbButton1.setIcon(new ThemeResource("../images/pic1.gif"));
pbButton1.addClickListener(controller);
panHelpToolbar.addComponent(pbButton1);
panHelpToolbar.setComponentAlignment(pbButton1, Alignment.MIDDLE_LEFT);
pbButton2= new Button();
pbButton2.setCaption("Button2 Text");
pbButton2.setImmediate(true);
pbButton2.setWidth("100%");
pbButton2.setHeight("-1px");
pbButton2.setStyleName(BaseTheme.BUTTON_LINK);
pbButton2.setIcon(new ThemeResource("../images/pic.gif"));
pbButton2.addClickListener(this);
panHelpToolbar.addComponent(pbButton2);
panHelpToolbar.setComponentAlignment(pbButton2, Alignment.MIDDLE_LEFT);
}

this.NavigationController is null

I m using Xamarin for iOS, Xamarin Studio v5.7.1
I having a small problem with the NavigationController.
I m pushing a ViewController programmatically like this:
ProfileViewController profileVC = ProfileViewController.ProfileViewControllerFromNib (this);
navController.PushViewController (profileVC, true)
And in the ViewDidLoad inside the ProfileViewController the NavigationController is null.
I thought to change the segue style to push like this smart guy said but with no success.
Any help will super welcome.
Thanks in advance.
Did you set the RootNavigationController of the window in your AppDelegate?
window.RootViewController = _rootNavigationController;
window.MakeKeyAndVisible ();

When are the bounds and font of a UITextView initialized in Xamarin Forms?

I'm trying to implement an Editor with hint text functionality for a Xamarin.Forms project. This is trivial in Android, because the underlying EntryEditText control has a Hint property. In iOS, the implementation is a bit more complex because the UITextView class does not implement hint text.
I don't like the technique, "set text to the placeholder, clear it if typing starts, return it if typing ends and the text is blank". It means I have to do extra work to tell if the control's blank, and there's a lot of fiddling with the text color involved. But I've been having so much trouble I'm going to have to resort to it. Maybe someone can help me with this.
I started with the answer to Placeholder in UITextView. I started a new Xamarin iOS project and stumbled through a rough Obj-C to C# conversion, and it worked great with a minor change: the Font property of the UITextView isn't initialized yet in the constructor, so I had to override AwakeFromNib() to set the placeholder label's font. I tested it and it worked, so I brought that file into a Xamarin Forms project, and things started getting a little nutty.
The first problem is it turns out apparently MonoTouch has some slight API differences in Xamarin Forms, such as using some types like RectangleF instead of CGRect. This was obvious, if not unexpected. I've been wrestling with some other differences for the past few days, and can't seem to overcome them in a way that makes me happy. Here's my file, trimmed down significantly because I've been trying all kinds of debugging things:
using System;
using MonoTouch.UIKit;
using MonoTouch.Foundation;
using MonoTouch.CoreGraphics;
using System.Drawing;
namespace TestCustomRenderer.iOS {
public class PlaceholderTextView : UITextView {
private UILabel _placeholderLabel;
private NSObject _notificationToken;
private const double UI_PLACEHOLDER_TEXT_CHANGED_ANIMATION_DURATION = 0.25;
private string _placeholder;
public string Placeholder {
get {
return _placeholder;
}
set {
_placeholder = value;
if (_placeholderLabel != null) {
_placeholderLabel.Text = _placeholder;
}
}
}
public PlaceholderTextView() : base(RectangleF.Empty) {
Initialize();
}
private void Initialize() {
_notificationToken = NSNotificationCenter.DefaultCenter.AddObserver(TextDidChangeNotification, HandleTextChanged);
_placeholderLabel = new UILabel(new RectangleF(8, 8, this.Bounds.Size.Width - 16, 25)) {
LineBreakMode = UILineBreakMode.WordWrap,
Lines = 1,
BackgroundColor = UIColor.Green,
TextColor = UIColor.Gray,
Alpha = 1.0f,
Text = Placeholder
};
AddSubview(_placeholderLabel);
_placeholderLabel.SizeToFit();
SendSubviewToBack(_placeholderLabel);
}
public override void DrawRect(RectangleF area, UIViewPrintFormatter formatter) {
base.DrawRect(area, formatter);
if (Text.Length == 0 && Placeholder.Length > 0) {
_placeholderLabel.Alpha = 1;
}
}
private void HandleTextChanged(NSNotification notification) {
if (Placeholder.Length == 0) {
return;
}
UIView.Animate(UI_PLACEHOLDER_TEXT_CHANGED_ANIMATION_DURATION, () => {
if (Text.Length == 0) {
_placeholderLabel.Alpha = 1;
} else {
_placeholderLabel.Alpha = 0;
}
});
}
public override void AwakeFromNib() {
base.AwakeFromNib();
_placeholderLabel.Font = this.Font;
}
protected override void Dispose(bool disposing) {
base.Dispose(disposing);
if (disposing) {
NSNotificationCenter.DefaultCenter.RemoveObserver(_notificationToken);
_placeholderLabel.Dispose();
}
}
}
}
A notable change here is relocation of the label's initialization from DrawRect() to the constructor. As far as I can tell, Xamarin never lets DrawRect() be called. You'll also note I'm not setting the Font property. It turned out in the iOS MonoTouch project, sometimes the parent's font was null and it's illegal to set the label's font to null as well. It seems at some point after construction Xamarin sets the font, so it's safe to set that property in AwakeFromNib().
I wrote a quick Editor-derived class and a custom renderer so Xamarin Forms could render the control, the Renderer is slightly of note because I derived from NativeRenderer instead of EditorRenderer. I needed to call SetNativeControl() from an overridden OnModelSet(), but peeking at the assembly viewer showed that EditorRenderer makes some private calls I'll have to re-implement in mine. Boo. Not posted because this is already huge, but I can edit it in if needed.
The code above is notable because the placeholder isn't visible at all. It looks like in iOS-oriented MonoTouch, you typically initialize a control with a frame, and resizing is a rare enough circumstance you can assume it doesn't happen. In Xamarin Forms, layout is performed by layout containers, so a constructor-provided frame is irrelevant. However, the size of the label is intended to be set in the constructor, so it ends up having negative width. Whoops.
I assumed this could be solved by moving instantiation of the label into AwakeFromNib(), or at least sizing it there. This is when I discovered that for some reason, AwakeFromNib() isn't called in the control. Welp. I tried to find an equivalent callback/event that happened late enough for the bounds to be set, but couldn't find anything on the iOS side. After trying many, many things, I noticed the custom renderer received property change events for the Xamarin Forms Model side of this mess. So, if I listen for Height/Width change events, I can then call a method on the label to give it a reasonable size based on the current control. That exposed another problem.
I cannot find a way to set the label's font to match the UITextView's font. In the constructor, the Font property is null. This is true in both the iOS and Xamarin Forms project. In the iOS project, by the time AwakeFromNib() is called, the property is initialized and all is well. In the XF project, it's never called, and even when I pull stunts like invoking a method from a 5-second delayed Task (to ensure the control is displayed), the property remains null.
Logic and iOS documentation dictates the default value for the font should be 17-point Helvetica. This is true for the placeholder label if I fudge the size so it's visible. It is not true for the UITextView control, though since it reports its font as null I'm unable to see what the font actually is. If I manually set it all is well, of course, but I'd like to be able to handle the default case. This seems like a bug; the box seems to be lying about its font. I have a feeling it's related to whatever reason the Xamarin.Forms.Editor class doesn't have a Font property.
So I'm looking for the answer to two questions:
If I'm extending an iOS control in XF to add a subview, what is the best way to handle sizing that subview? I've found Height/Width changes raise events in the renderer, is this the only available way?
When the property has not been set by a user, is the Font of a UITextView in Xamarin Forms ever set to a non-null value? I can live with a requirement that this control requires the font to be explicitly set, but it's yucky and I'd like to avoid it.
I'm hoping I've missed something obvious because I started barking up the wrong trees.
If I'm extending an iOS control in XF to add a subview, what is the
best way to handle sizing that subview? I've found Height/Width
changes raise events in the renderer, is this the only available way?
This is the only way I know of since the exposed elements of the renderer are so limited.
When the property has not been set by a user, is the Font of a
UITextView in Xamarin Forms ever set to a non-null value? I can live
with a requirement that this control requires the font to be
explicitly set, but it's yucky and I'd like to avoid it.
No, the Font is not assigned a default non-null value.

Displaying Map on Lwuit nokia s40

I'm using Lwuit to develop app on nokia s40 SDK 2.0
I have to add a Map to my application..
So i hav used the code given below but the screen doesnot display anything.
I get a blank screen. How can I display this on lwuit form or container?
(the code runs completely and exits without errors & 'END' is printed)
ApplicationContext.getInstance().setAppID("ruKXq--------Sbgq");
ApplicationContext.getInstance().setToken("kWRp_Vp---------AG7rw");
Display display = Display.getDisplay(COMPANY_Midlet.getInstance());
MapCanvas mapCanvas = new MapCanvas(display) {
public void onMapUpdateError(String description,
Throwable detail, boolean critical) {
// Error handling goes here.
}
public void onMapContentComplete() {
}
};
mapCanvas.getMapDisplay().setState(
new MapDisplayState(new GeoCoordinate(52.51, 13.4, 0), 10));
System.out.println(mapCanvas.getMapDisplay().getState());
display.setCurrent(mapCanvas);
System.out.println("END");
Architecturally the most elegant way would be to create a custom LWUIT component which encapsulates the MapCanvas and exposes a standard LWUIT interface - in other words basic use of an adaptor pattern. There is an example of this pattern to be found within the Nokia Projects Tourist Attractions example (the version updated for LWUIT). Additionally sample code for such a component can be found on GIT hub here

How do you resize a Bitmap under .NET CF 2.0

I have a Bitmap that I want to enlarge programatically to ~1.5x or 2x to its original size. Is there an easy way to do that under .NET CF 2.0?
One "normal" way would be to create a new Bitmap of the desired size, create a Graphics for it and then draw the old image onto it with Graphics.DrawImage(Point, Rectangle). Are any of those calls not available on the Compact Framework?
EDIT: Here's a short but complete app which works on the desktop:
using System;
using System.Drawing;
class Test
{
static void Main()
{
using (Image original = Image.FromFile("original.jpg"))
using (Bitmap bigger = new Bitmap(original.Width * 2,
original.Height * 2,
original.PixelFormat))
using (Graphics g = Graphics.FromImage(bigger))
{
g.DrawImage(original, new Rectangle(Point.Empty, bigger.Size));
bigger.Save("bigger.jpg");
}
}
}
Even though this works, there may well be better ways of doing it in terms of interpolation etc. If it works on the Compact Framework, it would at least give you a starting point.
The CF has access to the standard Graphics and Bitmap objects like the full framework.
Get the original image into a Bitmap
Create a new Bitmap of the desired size
Associate a Graphics object with the NEW Bitmap
Call g.DrawImage() with the old image and the overload to specify width/height
Dispose of things
Versions:
.NET Compact Framework
Supported in: 3.5, 2.0, 1.0

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