When using developing Widgets for Android it seems you are not able to add your own custom View classes to a AppWidgetProvider.
For example I created a custom class which extends View, this works fine when used within an Activity but the moment I add it to a Widget I get a "ClassNotFoundException" because Android seems to only allow a set of certain system widgets to be added.
I have seen some apps which look like they have made there own custom widgets. For example there is one that brings up a radial menu when clicked which shows application shortcuts. How are these being implemented? Is there a work around to using my own custom widget? They seem to have a canvas which they are able to draw on within the widget.
Okay quick example https://market.android.com/details?id=zombiesinthelab.widgets.droidpetwidget&feature=top-paid
So this widget is being done by just drawing ImageViews and updating them periodically opposed to using a canvas to draw the frames?
Android Widgets can only contain Layout-Widgets supported by RemoteViews. See this list:
A RemoteViews object (and,
consequently, an App Widget) can
support the following layout classes:
FrameLayout
LinearLayout
RelativeLayout
And the following widget classes:
AnalogClock
Button
Chronometer
ImageButton
ImageView
ProgressBar
TextView
> Descendants of these classes are not
supported.
Pay attention to the last sentence. You can not change this behaviour, it is hard coded in android.
I have not much idea on how to create widgets but following links can definitely help you:
1) http://developer.android.com/guide/topics/appwidgets/index.html
2) http://developer.android.com/guide/practices/ui_guidelines/widget_design.html
Related
I want to show my custom floating button on all screen in my app without putting it in each activity.
Do we have some Global Activity like put a code once will show the Custom View all screen and hide/remove when app killed
I tried lot of things like Screen Overlay display over all apps
Please check code here - How to display custom view on all screen in android from my library
I've never tried to do it the Java/Kotlin way. But have you considered using Fragments?
You can declare xml layout and code for one Activity with a FrameLayout container and an FAB. The container holds all your screens and they switch between each other in the container. The FAB is on top and therefore will be displayed no matter the screen.
The Activity has a reference to any screen that might be displayed in it, so the FAB can behave accordingly.
Not sure if this helps. Perhaps if I see some pictures, I could suggest better.
Related Read:
Creating a fragment: here
Fragment Transactions: here
I want to develop an Android app, where start page of the app GUI, will contain 4 vertical layouts in the main layout. Now, in each layout, I want to add buttons/slider dynamically from the app (instead of adding buttons/slider dynamically in the source code). That means, initially all these 4 layouts will be blank and when user will select any button or slider in another layout, to add it in any of this 4 layouts, the button or slider will be added in that layout. User will be able to add max 10 views in any vertical layout and the views can be either button, slider or custom view.
My attempt:
First I tried to create 4 vertical layout under the main layout for startup page and I got succeed.
I also find after searching that its possible to add views dynamically in layouts in android.
dynamically adding a view to activity layout
But most examples, add views dynamically in android by running loops, instantiating the desired view class and then add it in the main layout. Although, in this way, views are added dynamically in the layout, it is done by modifying the source code.
Is it possible to write the source code in a way, so that it can be done directly from the app? So that when user will click on Add a slider in "layout 1", a slider will be added in layout 1 and then again, when the user will click on "Add a button" in layout 1, a button will be added at the end of the slider. User will be able to customize button or slider properties. Also, if the user change the value of the slider, the app will remember its value.
Now, next time, when the app will be opened, those views will be there in the layouts, they will not be deleted and the values will remain unchanged (for example, a ticked check box will remain ticked), so I think I also need some kind of storage or properties manager.
My question is, is it possible to do this in android (because I never seen such apps in android) and if possible, any idea, how can I implement it?
I am totally new to android, so my knowledge is limited but I completed the basic tutorials on android app development and I have plugin development experience in eclipse.
Thanks a lot in. I will highly appreciate your help.
Of course it is possible:
Every layout (like LinearLayout, RelativeLayout etc.) extends the ViewGroup-class, which offers the addView-method.
To add a new view (like a Slider) to one of your layouts, just instantiate it programmatically (via new) in your activity and assign the appropriate LayoutParams to it
To store the state of user added content, it is the easiest to use SharedPreferences - a simple key-value-store which holds data over the application's lifecycle
Yes. This is possible. To create the Views dynamically, you simply have to either extend the class of the View or just say new Button(Context, AttributeSet); (Not only for Button's every View has a constructor that takes an attribute set and a context).
Using Layout.addView() you can add any View to the Layout.
Using SharedPreferences you can indicate what View belongs in what Layout.
If you decide to extend the View's class, make sure not to do too much in it. I tried that once and it just gave me an OOM (OutOfMemory Error) because I had a ton a Views trying to do stuff at the same time.
I have some problems with the layout and activity and I don't know are they different,are they related?
I think the layout is a place we can add or remove our views and activity is just a place that shows any thing in our layout, is this true?
An activity:
is an instance of Activity, a class in the Android SDK. An activity is responsible for
managing user interaction with a screen of information.
You write subclasses of Activity to implement the functionality that your app requires. A simple application may need only one subclass; a complex application can have many.
A layout:
defines a set of user interface objects and their position on the screen. A layout is made up of definitions written in XML. Each definition is used to create an object that appears on screen, like a button or some text.
A layout deals with the user interface. Its where you set all your views that will be visible on the user interface.
The code behind (.java) sets the layout you created as the content view and manipulates the behavior of the views you have set. For example, sets the text for a text view.
The activity then is the whole thing, the layout and the code behind.
An activity is the java code which attaches actions and puts content to/in a layout. For this the Activity loads the layout.
Briefly,
Activity is the java part of your projects. The program and any kind of algorithms are implemented here. Also layout views come to life in an activity.
Layout is where you organize the views in your page. But without activity, they have no meaning. Because in activity, you have to get these views and use them programmaticaly.
All together, you load views from layout to activity and in activies you implement your whole program.
A layout defines all the appearance of an app and this is of no use without a java program which helps in real functioning of that visual display.
Thus we define what an app does by writing its java code and a special java class called activity decides which layout to use at a particular instant and tells the app how to respond to the user.
I need to implement TextView widget in cocos2d-android-1 and don't know how please help
TextView textView = null;
textView.setText(R.string.billing_not_supported_message);
addChild(textView);
This code not working because addChild needs node. Please help really need.
I completely agree that the android version of cocos2d needs some serious 'standard UI' features adding to it.
At the moment, your only real option is to take a similar approach to my previous answer here
ANDROID:How to open web page in class extends CCLayer
whereby you have a layout which will put a textview on the screen (or you construct it yourself in your handler), and you use a handler from the activity which your scene is running in to show/hide it.
It's clunky and horrible but it works. In my field designer app i faced the same problem, but i also had to have a custom background to the text field, which resized with the text field, that had a rough edge, and the text view had to fall inside that rough edge so all the text was visible on the main bit of the background.
i achieve that using this same technique, but i created a layout xml file so that i had control over how the textview and it's background were displayed.
(note to show/hide the textview i had to give its root layout a constant ID and check for if that ID existed, and was visible, as when people touched outside it, i needed to make it vanish)
i'm making an app that requires indefinite textviews and images. i'm trying to implement a Pulse News app UI but having a hard time implementing one. so i thought of an idea to make a UI like that with the use of textviews, imageview and horizontal scroll view.
textview string values are from parsed xml online and images or the imageviews will be images from a specific directory in the sdcard that my app is using.
can anyone give me ideas how can i do it without using an xml layout or is there any or other options or ways for doing this? thanks...
You can create a viewgroup with one textview and an image. Then it can be added dynamically to your layout many times. This can be done by creating objects in a loop. You can change the content in each viewgroup at the time of inflation.
though i dont know what exactly how pulse new app looks like, but by going through your question (horizontal scroll view in particular) I guess you want to implement a "Gallery" type implementation where in you can swipe left/right on page basis.
If my assumption is correct then you will like to see to ViewPager of android backward compatiblity pkg.