Develop Reference

Flutter Banner on the top of the app (Android)

Hello, i want to delete the banner that appears at the top of the MaterialApp only happens on Android, in iOs i don't have that issue.
I used the very_good cli
I tried to view if the android_manifest.xml have some information but i didn't find anything that could help me.
I am expecting to delete the black banner with the appName

This could be an AppBar which is located inside a Scaffold. Try looking for it in the project and delete it.
Alternatively this could be based on the android activitie's theme. In the android specific module, open the manifest.xml file and check which themes are used in the activities:
<manifest ...>
<application
...>
<activity
android:name=".MainActivity"
android:exported="true"
android:launchMode="singleTop"
android:theme="#style/LaunchTheme"
android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
android:hardwareAccelerated="true"
android:windowSoftInputMode="adjustResize">
...
</activity>
<meta-data
android:name="io.flutter.embedding.android.NormalTheme"
android:resource="#style/NormalTheme"
/>
...
</application>
</manifest>
In this case, flutter uses LaunchTheme and after the launch it applies NormalTheme.
Open then the styles.xml file (usually located at: android/app/src/main/res/values/styles.xml). Find the styles that match the styles which are used by the activity and check if they both inherit from a NoTitleBar style.
<?xml version="1.0" encoding="utf-8"?>
<resources>
<!-- Theme applied to the Android Window while the process is starting when the OS's Dark Mode setting is off -->
<style name="LaunchTheme" parent="#android:style/Theme.Light.NoTitleBar">
<!-- Show a splash screen on the activity. Automatically removed when
Flutter draws its first frame -->
<item name="android:windowBackground">#drawable/launch_background</item>
</style>
<!-- Theme applied to the Android Window as soon as the process has started.
This theme determines the color of the Android Window while your
Flutter UI initializes, as well as behind your Flutter UI while its
running.
This Theme is only used starting with V2 of Flutter's Android embedding. -->
<style name="NormalTheme" parent="#android:style/Theme.Light.NoTitleBar">
<item name="android:windowBackground">?android:colorBackground</item>
</style>
</resources>

Missing style error when adding a new textview component into the layout

I've searched for the articles that are discussing about the same topic,
but it accidentally seems like there aren't any.
I actually had the problem when setting the layout & edit the style xml file like below:
<!-- Base application theme. -->
<style name="NoTitleBarFulScn" parent="#android:style/Theme.NoTitleBar.Fullscreen">
Customize your theme here.
<item name="colorPrimary">#color/colorPrimary</item>
<item name="colorPreimaryDark">#color/colorPrimaryDark</item>
<item name="ceolorAccent">#color/colorAccent</item>
</style>
And then indicate the manifest file to use the NoTitleBarFulScn style:
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/NoTitleBarFulScn"
android:screenOrientation="landscape" >
<activity android:name=".MainActivity"
android:screenOrientation="landscape">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
Problem solved till here,
but the "Missing styles. Is the correct theme chosen for this layout?" error shows again when I was simply adding a new textview component...(It also shows an error about textview attributes missing below the missing style one.)
I tried also the sdk version setting & "invalidate caches / restart" option, but still doesn't work.
Also it seems like the new version of android studio has been set not to show the detail of the missing attributes it's saying, I still don't know where to find it.
Please give me some advice if possible,
thank you so much!

I've found the solution that I think is the most likely cause in the very beginning,
just simply add
<item name="android:textEditSuggestionItemLayout"></item>
<item name="android:textEditSuggestionContainerLayout"></item>
<item name="android:textEditSuggestionHighlightStyle"></item>
into the style definition of the XML file,
however it seems like the new version of android studio has been set not to show the detail of the missing attributes it's saying, I still don't know where to find it.

How can I achieve this theme with AppCompat?

I am trying to create this theme for one, and just one of my activities:
Since I am learning how this styles work, and I am now beginning to be aware that we have more different & incompatible ways of styling in android than atoms in the whole universe. So I've tried to learn from this site: http://jgilfelt.github.io/android-actionbarstylegenerator
However when I try to apply its theme in my project that is using AppCompat I get the
java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
error type.
I am extending from ActionBarActivity in my tabbed activity and I don't feel safe going back now (someone suggested extending Activity to solve this issue), since in previous posts I was suggested to use AppCompat, and ActionBarActivity seems somehow to be AppCompat related.
I've spent all my week googling for solutions and I've came across these problems:
The official Android styling documentation is deprecated.
The code generated by Android Studio is also deprecated in method such as this.*
http://jgilfelt.github.io/android-actionbarstylegenerator is deprecated.
BUT, to the point now, this is what I have at the moment:
So, the only thing I am not being able to do is
putting the logo in the top left corner of the screen (in the action bar), in a way that only affects the action bar of this particular activity, (Done)
make the orange bar showing which tab is selected.
How can I achieve this in the most simple way?
This is my values/style.xml file:
<resources>
<!-- Base application theme. -->
<style name="SmartCampusTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<item name="colorPrimary">#color/actionbar_bg_color</item>
</style>
<style name="GenericProgressIndicator" parent="#android:style/Widget.ProgressBar.Small">
<item name="android:layout_width">wrap_content</item>
<item name="android:layout_height">wrap_content</item>
<item name="android:indeterminate">true</item>
</style>
</resources>
My AndroidManifest.xml:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="greensmartcampus.eu.smartcampususerfeedbackapp">
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:logo="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/SmartCampusTheme">
<!-- Splash screen while connecting to the web-server -->
<activity
android:name=".HomeScreen"
android:label="#string/title_activity_home_screen"
android:parentActivityName=".AbstractPortraitActivity">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="greensmartcampus.eu.smartcampususerfeedbackapp.AbstractPortraitActivity" />
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<!-- The activity where all actions take place -->
<activity
android:name=".ControlActivity"
android:label="#string/title_activity_home_screen"
android:parentActivityName=".AbstractPortraitActivity">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="greensmartcampus.eu.smartcampususerfeedbackapp.AbstractPortraitActivity" />
</activity>
</application>
</manifest>
*Ps. it's funny how the most up-to-date Android Studio generates deprecated code for tabbed activities and then complains about it being deprecated as if it is your fault...
Important Note: I am a huge fan of MVC and a modularity priest (OSGi practitioner). So I would love if all these styling solutions could be all contained in the style and drawing XML files (as they should be if I correctly recall), the layout information is all contained in my layout files and my java files only contain code about behavior. For example I could just show the action bar icon with java through getSupportActionBar().setDisplayShowHomeEnabled(true), but inserting layout related stuff in java disrupts the MVC pattern. Also, the website that I mention above can create the layout with the icon in the actionbar without using a single java line. I just need to know how can that be done with AppCompat, which apparently is what I am using because other solutions are deprecated.

ActionBar is missing after switching to API21 AppCompat

While working on the Big Nerd Ranch's Criminal Intent project when I updated my AppCompat library from API 19 to API 21 I lost ActionBar. I have tried changing themes around but I can't find a way to get ActionBar.
The full source code is available here.
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.sudhirkhanger.app.criminalintent" >
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity android:name=".CrimeListActivity" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".CrimePagerActivity"
android:label="#string/app_name" >
</activity>
</application>
</manifest>
style.xml
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
</style>
</resources>
Thanks.

To use appcompat-v7, you must inherit from ActionBarActivity. CrimeListActivity inherits from SingleFragmentActivity, which in turn inherits from FragmentActivity, not ActionBarActivity.

I also had that problem I moved the whole line (android:theme="#style/AppTheme) and its works! The theme is a dark theme which looks better.

I came across this issue as well.
The solution is remove the style tag from the manifest.xml (android:theme="#style/AppTheme").
It will use the holo theme, but with the Action Bar.

ActionBarCompat, supportRequestWindowFeature(Window.FEATURE_NO_TITLE) and expected behavior

I'm uncertain of the expected behavior when using ActionBarCompat and supportRequestWindowFeature(Window.FEATURE_NO_TITLE). I see two different behaviors depending on Android version:
On a Android ICS (possibly also from Android 3.0?) device using ActionBarCompat a call to supportRequestWindowFeature(Window.FEATURE_NO_TITLE) would hide the combined titlebar/actionbar
On a Android 2.3 device the actionbar is still visible even though supportRequestWindowFeature(Window.FEATURE_NO_TITLE) is called.
Some additional information: My activities extend android.support.v7.app.ActionBarActivity and my app uses the #style/Theme.AppCompat.Light theme. supportRequestWindowFeature(Window.FEATURE_NO_TITLE) is called before setContentView(). I never make any call to either getSupportActionBar().show() or hide().
So, what's the expected behavior? When I used ABS a call to requestWindowFeature(Window.FEATURE_NO_TITLE) would hide the titlebar/actionbar regardless of Android version.
How would I go about having an android app where some activies use an actionbar while others have none? Should they not extend the same base class?

So I've found a solution to this but it uses styles applied via the AndroidManifest (and therefore needs no code). Keep in mind that this will almost definitely only work if you're using the AppCompat library.
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="..."
android:versionCode="1"
android:versionName="1.0">
<uses-sdk
android:minSdkVersion="7"
android:targetSdkVersion="19" />
<application
android:allowBackup="false"
android:icon="#drawable/launcher"
android:label="#string/app_name"
android:theme="#style/Theme.AppCompat.Light.DarkActionBar">
<activity
android:label="#string/log_in"
android:name=".activities.LogInActivity"
android:parentActivityName=".activities.MainActivity">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value=".activities.MainActivity" />
</activity>
<activity
android:label="#string/app_name"
android:name=".activities.MainActivity"
android:theme="#style/Theme.AppCompat.Light.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:label="#string/sign_up"
android:name=".activities.SignUpActivity"
android:parentActivityName=".activities.MainActivity">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value=".activities.MainActivity" />
</activity>
</application>
</manifest>
Note how I've got a global theme applied directory to the <application> tag, and then also a theme that's individually applied to my MainActivity class through its own <activity> tag. That is the only Activity where I want the Action Bar to be hidden; everywhere else I want it to be visible (which is why I don't have individual themes applied to any of my other Activities as I instead let them inherit from the global application theme).
But you'll quickly find that Theme.AppCompat.Light.NoActionBar doesn't actually exist. This is because I had to create that style myself, which requires two different styles.xml files:
values/styles.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<style name="Theme.AppCompat.Light.NoActionBar" parent="Theme.AppCompat.Light">
<item name="windowActionBar">false</item>
<item name="android:windowNoTitle">true</item>
</style>
</resources>
values-v11/styles.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<style name="Theme.AppCompat.Light.NoActionBar" parent="Theme.AppCompat.Light">
<item name="android:windowActionBar">false</item>
<item name="android:windowNoTitle">true</item>
</style>
</resources>
You must use two different styles.xml files for this as the android:windowActionBar flag didn't exist before Android API version 11.