I've recently started working on an Android app. I'm not a programming noob, I have been programming in Java since 2009, but this is my first Android app. I have tried following some tutorials on how to set the background colour but it simply isn't working for me. I can't work out what I'm doing wrong.
In my layout directory I have files called: main.xml and view_fact.xml. They both use the linear layout and my LinearLayout Tag is as follows:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#color/background_grey"
>
And in my "values" directory I the contents of "strings.xml" is:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_name">Facts</string>
<color name="background_grey">#E8E8E8</color>
</resources>
But the background colour is not changing from the default black.
I've also tried adding: "android:theme="#android:style/Theme.Light"" in my AndroidManifest.xml file.
None of this is working, any suggestions?
Thank you.
On my view_fact.xml page it looks like this:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#color/background_grey"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Fact:"
android:padding="10dp"
android:textColor="#080808"
/>
<TextView
android:id="#+id/factData"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="10dp"
android:text=""
/>
<Button
android:id="#+id/anotherFactButton"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Another Fact"/>
</LinearLayout>
What's interesting is that the text in "factData" is grey, while the text: "Fact:" in the Text View above is white, and I've tried to change it's colour to red and it doesn't work. It stays white.
Any suggestions? I still haven't managed to get this working; thank you.
If you want to use #color/color_name you have to create a Color.xml file and then it will be accessible in the manner you tried to use it.
Forgive the somewhat obvious questions, but: are you calling setContentView(R.layout.main) in your Activity onCreate? Is there something else in the layout that is filling the LinearLayout and covering the background grey?
Looking at the pastie you linked in the comment I think you need to remove the <?xml version="1.0" encoding="utf-8"?> line at the start. Eclipse won't build a freshly created app with that xml root in a layout..
Although that's strange as the first two examples I've found on the Android Developer site (for example) include it
I'd be interested to see what happens if you remove that line...
In Eclipse if I use
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#E8E8E8"
>
then the background colour changes.
If I change that to
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#string/background_grey"
>
by adding <string name="background_grey">#E8E8E8</string> to /res/values/strings.xml the background changes.
This also works if I declare it as android:background="#color/background_grey" in the layout and <color name="background_grey">#E8E8E8</color> in strings.xml
and if I setup res/values/colors.xml <= I've used colors.xml (while you've used color.xml) however http://developer.android.com/guide/topics/resources/more-resources.html tells us the filename is arbitrary as you can see by the declaration working in the strings.xml file
<?xml version="1.0" encoding="utf-8"?>
<resources>
<color name="background_grey">#E8E8E8</color>
</resources>
and declare the layout as
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#color/background_grey"
>
then the background also changes...
If it doesn't behave the same for you then there's something funky going on or you're using a different layout than the simple example above and, well, there's something funky going on in that layout.
Okay, I've tried lots of different methods of trying to set the background colour and none of them are working. And I'm now having problems with text not updating. So I'm going to try remaking it. Using eclipse and ill make a new question if I'm still having issues. Thanks for the suggestions.
Related
I'd like to change and align the text, and possibly add features on appbar in the screen above.
However, it'd be best if I could find and modify the text and align it IF I don't intend to add features.
But then I wasn't able to find where in android studio I could change the text.
I thought I could find one in the main activity xml file but I couldn't. I looked up at themes.xml and AndroidManifest.xml but couldn't find a clue.
Here is first 13 lines of my main activity xml file just in case.
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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"
tools:context=".MainActivity">
<SurfaceView
android:id="#+id/surface_view"
android:layout_width="match_parent"
android:layout_height="480dp"
app:layout_constraintTop_toTopOf="parent"/>
So, to cut it short, where in android studio can I change the text in toolbar? or appbar? above in the screen without having to create toolbar.xml? (+ align the text in the center and change text color)
Apparantly you don't have toolbar implemented in your xml layout
In Your style file make sure you set it to noActionBar
<style name="Theme.ChatApp" parent="Theme.AppCompat.Light.NoActionBar">
Then you have to add your own toolbar
<androidx.appcompat.widget.Toolbar
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/toolbar"
android:background="#color/white"
app:navigationIcon="#drawable/ic_baseline_dashboard_24"
app:title="here you can put your title"/>
In your activity reference your toolbar in your onCreate
setSupportActionBar(findViewById(R.id.toolbar)
PS : If you are using MaterialToolbar please consider add this material library
implementation 'com.google.android.material:material:1.1.0'
I'm trying to set up a basic BottomActionBar with an attached FloatingActionButton. Currently, everything seems to work, aside from the background of the bar. If I use android:background="some_background_color", the bar is filled in with the desired color.
The problem is that I want my FAB to be cradled, and this approach seems to be incompatible with fabCradleMargin and fabCradleRoundedCornerRadius, as the background bar is unaffected by modifying these values.
All tutorials indicate that app:backgroundTint="some_background_color" is the way to go, but my action bar remains unaffected by this. I've set my API to >= 21, so as far as I know, there are no issues there.
My XML file:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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"
tools:context=".MainActivity">
<androidx.coordinatorlayout.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_constraintBottom_toBottomOf="parent">
<com.google.android.material.bottomappbar.BottomAppBar
android:id="#+id/bottom_app_bar"
style="#style/Widget.MaterialComponents.BottomAppBar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
app:backgroundTint="#color/colorPrimary"
app:fabAlignmentMode="center"
app:fabAttached="true"
app:fabCradleMargin="10dp"
app:fabCradleRoundedCornerRadius="10dp" />
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="#+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/ic_add_white_24dp"
app:layout_anchor="#+id/bottom_app_bar"
app:layout_anchorGravity="center_horizontal"
app:fabSize="normal"/>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
The backgroundTint has no effect on the bar; it remains completely white.
Sorry if this is an elementary question; I'm quite new to Android and have spent quite a while searching for a solution to no avail.
I tested your code
it shows an error for BottomAppBar so I findout this code app:fabAttached="true" is Undefined...
remove it and it will work perfectly.
Goodluck.
I'm creating an free Android application and I'm using OpenStreetMap (OSMdroid library). I have a question. On the webpage: https://www.openstreetmap.org/copyright
I have read, that I should put a text in the corner of map activity (#OpenStreetMap contributors).
How to do this?
I'd like my app to be comply with the OSM license.
Regards
There is a built in copyright overlay for displaying the notice based on the current tile source.
Edit, sample code is below
//Copyright overlay
mCopyrightOverlay = new CopyrightOverlay(context);
mMapView.getOverlays().add(this.mCopyrightOverlay);
Basically, whatever the current tile source is, the text overlay will be drawn.
When you have your layout file simply add a TextView with "#OpenStreetMap contributors" to it. (I recommend to use a RelativeLayout)
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<org.osmdroid.views.MapView android:id="#+id/map"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentEnd="true"
android:text="OpenStreetMap Contributors" />
</RelativeLayout>
I saw in other apps that on startup they all show this and a few seconds later it is fading out so you can use a delayed animation for that.
textView.animate().setStartDelay(3000).alpha(0).setDuration(1000).start();
I have used fragments to define a simple splitview, in the right site i used a layout containing videoview the xml code is:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<VideoView
android:id="#+id/tvT"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
</LinearLayout>
and in the left site in another fragment layout I have defined some buttons to play different videos, The program is running well in emulators, but when I run it on device, the videoview overlapped the whole area and creates a horrible look, what should I do?
You need to post more of your code if you can; what you have posted isn't really enough for people to help you. [Edit: Darn, I thought this was trivial enough to be automatically moved to a comment on the original question :-\ ]
May you could try with "fill_parent" because the video could be to big and uses the hole display:
<VideoView
android:id="#+id/tvT"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
If you can it would be good if you post some code how you setup your fragments.
I have followed this example. However, when I port it to my phone (in order to use the camera), the preview is flipped 90 degrees to the left. Other than that it is working fine.
My question is then: how do I "unflip" the preview?
Here is the content of my layout file:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal">
<android.view.SurfaceView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/preview"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
</android.view.SurfaceView>
</LinearLayout>
Also, when I try to turn the phone myself it stays in 'landscape' mode.
Thanks in advance!
I had the same issue before. I just added a parameter to rotate the view 90. Add this parameter to the surface changed function:
parameters.setRotation(90);