Develop Reference

Black box in screen after pressing Android menu button

I am creating a library class in Android Studio for my internship. I have created a custom RelativeLayout that inflates the layout shown below.
I can't find this issue anywhere, so I hope someone is able to help me out.
I have a layout file that looks like this:
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<FrameLayout
android:id="#+id/videoFrame"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_centerInParent="true"
android:background="#color/wallet_holo_blue_light">
<VideoView
android:id="#+id/videoBackground"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="center"
android:background="#null"/>
</FrameLayout>
</RelativeLayout>
I do need the FrameLayout, to be able to scale the VideoView where the VideoView's width is bigger then the parent this Layout is inflated into. I resize this VideoView dynamically on runtime-level, but that all works fine.
When I start the activity with this VideoView, everything is fine.
Whenever I hit the Android "Windows"-button and return to the Activity, a black box appears.
Screenshots
It also happens in Portrait mode. Then the black box is even bigger than half the screen.
After changing screenOrientation, so rotating my tablet, for example, the black box is gone again.
I really have no clue, does anyone know what the problem might be?

Visibility of Gone takes still space of particular control in android?

I am using the LinearLayout and inside there's button I am making visibilty gone based on supported states. SupportedStatuses are true then making Button as Visible but SupprtedStatuse are false then making button as Gone.
This is in a header and Button is Gone but still takes up the space.
Here is the Layout which I am using.
<LinearLayout
android:id="#+id/llparentView"
android:layout_width="match_parent"
android:layout_height="wrap_content
android:orientation="vertical">
<Button
android:id="#+id/btn_change_status"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</LinearLayout>
Anybody have a good solution then it helps me a lot.

You could use a FrameLayout around whatever layout you are using
For example:
<FrameLayout android:layout_width="match_parent" android:layout_height="wrap_content">
<!-- put your views here -->
</FrameLayout>
This will ensure when using View.GONE the FrameLayout collapses on the space.

Try to wrap your button in another Linear/Frame layout and change their visibility as well.

How to position a view off-screen in Android layout

I'm using the Scene/Transition system introduced in 4.4 to simply move an image view from the left to the center of the screen. So the layout for my first scene requires the image to be off screen. I tried android:layout_marginRight but that no effect. What is the correct way to do this?

Use the property translationX or translationY with a negative value. This property sets the horizontal/vertical location of this view relative to its left/top position. You will not see the view off screen in the preview. Run your app and the view must be hidden.
Example:
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.design.widget.FloatingActionButton
android:id="#+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|start"
android:layout_margin="16dp"
android:translationX="-72dp"/>
</FrameLayout>
And then in the activity or fragment simply invoke the animate() function.
FloatingActionButton button = (FloatingActionButton)findViewById(R.id.button);
button.animate().translationX(0);

Was thinking one could make the image be to the right of something that is already at the right side, that should keep it off screen. Also, potentially just make it "gone" and then on transtion make it appear.

How to use two activites in a single screen in android?

I want to display two different activities in a single screen how can i do that in android?Please if anybody has idea share it.And I don't wanna use fragments.
I want to display a screen which contains some fields and below(at the bottom of the screen) I want another screen with some buttons.
Is this possible in android?
If so, How can i do this ?

You can't have two activities in one screen. You can have only one. So, ultimate solution is Fragments.

An activity is not directly a visual component, so I'm thinking that what you're really asking is how to have a single activity display different views.
There's nothing that says you can't rerun setContentView() with a different layout/view ID. But there's another non-fragments way of doing what your probably want.
You can define more than one full-size (match_parent) view in a layout. What you want to do is set the visibility for one of them to "visible" with android:visibility="visible" and all the others to "gone" with android:visibility="gone".
Then when you want to switch the displayed view, you'll run setVisibility(View.GONE) on the outgoing view and setVisibility(View.VISIBLE) on the incoming. It's important to use GONE and not INVISIBLE or the layouts won't render correctly.
Sample layout file:
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >
android:layout_width="match_parent"
android:layout_height="match_parent" >
<ImageView
android:id="#+id/img"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:visibility="visible" />
<SurfaceView
android:id="#+id/video"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:visibility="gone" />
<WebView
android:id="#+id/web"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:visibility="gone" />
</FrameLayout>
Sample Code to switch view:
video.setVisibility(View.VISIBLE);
img.setVisibility(View.GONE);
web.setVisibility(View.GONE);
That said, you probably want to learn how to use fragments since you can handle switching the view along with other state in a single unit of work (a transaction). But the above approach above does work for simple view changes.

Android bringToFront GridView Issue

I'm developing an app which contains an image at the upper half of the screen and a gridview in the half below, like this:
<de.test.gridview.Image
android:id="#+id/image_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:fadingEdgeLength="0dp"
android:scrollbars="none"
android:visibility="gone" />
<de.test.gridview.DraggableGridView
android:id="#+id/grid_view1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#id/topnews_container"
android:background="#FFF"
android:gravity="center"
android:numColumns="auto_fit"
android:stretchMode="none"
android:tag="grid_view_tag" >
</de.test.gridview.DraggableGridView>
The Image is set to visibility=gone and set to visible in the code manually later on.
When I now drag on of the childs of the gridview I cant be able to drag them over the image in the upper half of the screen. They are always behind the image, but never in front of it. I've tried to use
gridView.bringToFront()
and also within the gridView I tried this function. I also tried this on the children of the gridview with gridView.bringChildToFront(child). But nothing worked.
Does anybody have an idea?

I guess view with property set to View.GONE is not operational via bringToFront(). So I believe the following will work (if you are trying to bring the grid to the front/top of z):
gridView.setVisibility(View.INVISIBLE);
gridView.bringToFront();
But its looks like you want to bring imageView to the front (making gridView behind instead of front). If so you need to:
imageView.setVisibility(View.INVISIBLE);
imageView.bringToFront();